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Sample records for low-energy x-ray irradiation

  1. 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

  2. Low energy (soft) x rays

    International Nuclear Information System (INIS)

    Hoshi, Masaharu; Antoku, Shigetoshi; Russell, W.J.; Miller, R.C.; Nakamura, Nori; Mizuno, Masayoshi; Nishio, Shoji.

    1987-05-01

    Dosimetry of low-energy (soft) X rays produced by the SOFTEX Model CMBW-2 was performed using Nuclear Associates Type 30 - 330 PTW, Exradin Type A2, and Shonka-Wyckoff ionization chambers with a Keithley Model 602 electrometer. Thermoluminescent (BeO chip) dosimeters were used with a Harshaw Detector 2000-A and Picoammeter-B readout system. Beam quality measurements were made using aluminum absorbers; exposure rates were assessed by the current of the X-ray tube and by exposure times. Dose distributions were established, and the average factors for non-uniformity were calculated. The means of obtaining accurate absorbed and exposed doses using these methods are discussed. Survival of V79 cells was assessed by irradiating them with soft X rays, 200 kVp X rays, and 60 Co gamma rays. The relative biological effectiveness (RBE) values for soft X rays with 0, 0.2, 0.7 mm added thicknesses of aluminum were 1.6, which were compared to 60 Co. The RBE of 200 kVp X rays relative to 60 Co was 1.3. Results of this study are available for reference in future RERF studies of cell survival. (author)

  3. 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®

  4. 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)

  5. Dose conversion factors and linear energy transfer for irradiation of thin blood layers with low-energy X rays

    International Nuclear Information System (INIS)

    Verhaegen, F.; Seuntjens, J.

    1994-01-01

    For irradiation of thin samples of biological material with low-energy X rays, conversion of measured air kerma, free in air to average absorbed dose to the sample is necessary. In the present paper, conversion factors from measured air kerma to average absorbed dose in thin blood samples are given for four low-energy X-ray qualities (14-50 kVp). These factors were obtained by Monte Carlo simulation of a practical sample holder. Data for different thicknesses of the blood and backing layer are presented. The conversion factors are found to depend strongly on the thicknesses of the blood layer and backing layer. In radiobiological work, knowledge of linear energy transfer (LET) values for the radiation quality used is often required. Track-averaged LET values for low-energy X rays are presented in this work. It is concluded that the thickness of the sample does not influence the LET value appreciably, indicating that for all radiobiological purposes this value can be regarded as a constant throughout the sample. Furthermore, the large difference between the LET value for a 50 kV spectrum found in this work and the value given in ICRU Report 16 is pointed out. 16 refs., 7 figs., 1 tab

  6. A track length estimator method for dose calculations in low-energy X-ray irradiations. Implementation, properties and performance

    Energy Technology Data Exchange (ETDEWEB)

    Baldacci, F.; Delaire, F.; Letang, J.M.; Sarrut, D.; Smekens, F.; Freud, N. [Lyon-1 Univ. - CREATIS, CNRS UMR5220, Inserm U1044, INSA-Lyon, Centre Leon Berard (France); Mittone, A.; Coan, P. [LMU Munich (Germany). Dept. of Physics; LMU Munich (Germany). Faculty of Medicine; Bravin, A.; Ferrero, C. [European Synchrotron Radiation Facility, Grenoble (France); Gasilov, S. [LMU Munich (Germany). Dept. of Physics

    2015-05-01

    The track length estimator (TLE) method, an 'on-the-fly' fluence tally in Monte Carlo (MC) simulations, recently implemented in GATE 6.2, is known as a powerful tool to accelerate dose calculations in the domain of low-energy X-ray irradiations using the kerma approximation. Overall efficiency gains of the TLE with respect to analogous MC were reported in the literature for regions of interest in various applications (photon beam radiation therapy, X-ray imaging). The behaviour of the TLE method in terms of statistical properties, dose deposition patterns, and computational efficiency compared to analogous MC simulations was investigated. The statistical properties of the dose deposition were first assessed. Derivations of the variance reduction factor of TLE versus analogous MC were carried out, starting from the expression of the dose estimate variance in the TLE and analogous MC schemes. Two test cases were chosen to benchmark the TLE performance in comparison with analogous MC: (i) a small animal irradiation under stereotactic synchrotron radiation therapy conditions and (ii) the irradiation of a human pelvis during a cone beam computed tomography acquisition. Dose distribution patterns and efficiency gain maps were analysed. The efficiency gain exhibits strong variations within a given irradiation case, depending on the geometrical (voxel size, ballistics) and physical (material and beam properties) parameters on the voxel scale. Typical values lie between 10 and 103, with lower levels in dense regions (bone) outside the irradiated channels (scattered dose only), and higher levels in soft tissues directly exposed to the beams.

  7. Low energy x-ray spectrometer

    International Nuclear Information System (INIS)

    Woodruff, W.R.

    1981-01-01

    A subkilovolt spectrometer has been produced to permit high-energy-resolution, time-dependent x-ray intensity measurements. The diffracting element is a curved mica (d = 9.95A) crystal. To preclude higher order (n > 1) diffractions, a carbon x-ray mirror that reflects only photons with energies less than approx. 1.1 keV is utilized ahead of the diffracting element. The nominal energy range of interest is 800 to 900 eV. The diffracted photons are detected by a gold-surface photoelectric diode designed to have a very good frequency response, and whose current is recorded on an oscilloscope. A thin, aluminium light barrier is placed between the diffracting crystal and the photoelectric diode detector to keep any uv generated on or scattered by the crystal from illuminating the detector. High spectral energy resolution is provided by many photocathodes between 8- and 50-eV wide placed serially along the diffracted x-ray beam at the detector position. The spectrometer was calibrated for energy and energy dispersion using the Ni Lα 1 2 lines produced in the LLNL IONAC accelerator and in third order using a molybdenum target x-ray tube. For the latter calibration the carbon mirror was replaced by one surfaced with rhodium to raise the cut-off energy to about 3 keV. The carbon mirror reflection dependence on energy was measured using one of our Henke x-ray sources. The curved mica crystal diffraction efficiency was measured on our Low-Energy x-ray (LEX) machine. The spectrometer performs well although some changes in the way the x-ray mirror is held are desirable. 16 figures

  8. DCARR: a spectrograph for measuring low-energy x rays

    International Nuclear Information System (INIS)

    Anon.

    1978-01-01

    DCARR, the Differential Critical Angle Reflection Refraction detector system, is described. This detector was designed to measure low-energy x rays, 500 to 5000 eV, with a high degree of resolution, 250 eV. DCARR was developed because these low-energy measurements are of interest in the diagnostics of x-radiation in nuclear tests and available equipment could not make measurements at this low an energy in field tests. DCARR is a versatile piece of equipment that can also be used as a laboratory tool, such as in measuring the low-energy x rays emitted by lasers and various x-ray machines

  9. Low Energy X-Ray Diagnostics - 1981.

    Science.gov (United States)

    1981-01-01

    41MEAS) Opt. Comm., 9, 246, (1973); also Phys. Rev. A, ( MODELED ) .01 11, 989, (1975). 13. R. Thack, H. Mahr, C. L. Tang, and P. L. Hartman , Phys. Rev...Transmission Gratings: R. Tatchyn and I. Lindau 301 Analysis and Modeling Results Holographic X-Ray Gratings to be Produced at P.L. Csonka and R...orbit. The degree of polarization depends on the Calfonia ad CSR an8 eVstorage ring at Cornell electron energy, wavelength, and vertical viewing Univrsit

  10. High-resolution imaging of coronary calcifications by intense low-energy fluoroscopic X-ray obtained from synchrotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Ohtsuka, S.; Sugishita, Y.; Takeda, T.; Itai, Y.; Tada, J.; Hyodo, K.; Ando, M. [Inst. of Clinical Medicine, Univ. of Tsukuba, Ibaraki (Japan). Dept. of Cardiology

    2000-07-01

    In order to obtain an intense monochromatic low-energy X-ray from synchrotron radiation (SR) and apply it to detect coronary calcifications, the SR beam was reflected with a silicon crystal to be expanded (150 mm in height and 80 mm in width) and to be monochromatized at an energy level of 37 keV. The X-ray was intermittently irradiated to obtain dynamic imaging of 30 images/s. Images were recorded by a digital fluorography system. The low-energy X-ray from SR sharply visualized calcification of coronary arteries, while conventional X-ray could not visualize coronary calcification. The intense monochromatic low-energy X-ray from SR is sensitive, has high-resolution for imaging coronary calcification and may serve as a screening method for coronary artery disease.

  11. Photoemission measurements for low energy x-ray detector applications

    International Nuclear Information System (INIS)

    Day, R.H.

    1981-01-01

    Photoemission has been studied for nearly 100 years as both a means of investigating quantum physics, and as a practical technique for transducing optical/x-ray photons into electrical currents. Numerous x-ray detection schemes, such as streak cameras and x-ray sensitive diodes, exploit this process because of its simplicity, adaptability, and speed. Recent emphasis on diagnostics for low temperature, high density, and short-lived, plasmas for inertial confinement fusion has stimulated interest in x-ray photoemission in the sub-kilovolt regime. In this paper, a review of x-ray photoemission measurements in the 50 eV to 10 keV x-ray region is given and the experimental techniques are reviewed. A semiempirical model of x-ray photoemission is discussed and compared to experimental measurements. Finally, examples of absolutely calibrated instruments are shown

  12. Low energy X-ray radiation impact on coated Si constructions

    International Nuclear Information System (INIS)

    Adliene, D.; Cibulskaite, I.; Meskinis, S.

    2010-01-01

    Low energy X-ray radiation impact on the coated Si structures is discussed in this paper. Experimental sandwich structures consisting of amorphous hydrogenated a:C-H or SiO x -containing DLC films were synthesized on Si wafers using direct ion deposition method and exposed to low energy (medical diagnostic range) X-ray photons. Irradiation of samples was performed continuously or in sequences and protective characteristics of the irradiated DLC films were investigated. Experimental data were used as the input data for Monte Carlo modelling of X-ray scattering effects in the coated silicon constructions, which affect significantly the 'signal to noise ratio' in DLC-coated Si structures proposed for their application in medical radiation detectors. Modelling results obtained in the case of DLC coatings were compared to the results of calculations performed for other commonly used combinations coating-detector material. The evaluation method of coated structures for their possible application in medical radiation detector constructions has been proposed in this paper. It is based on the best achieved compatibility between the appropriate mechanical characteristics, coating's resistance against the radiation damage and the lowest estimated scattering to total dose ratio in the coated radiation sensitive volume.

  13. Gas Pixel Detectors for low energy X-ray polarimetry

    International Nuclear Information System (INIS)

    Spandre, Gloria

    2007-01-01

    Gas Pixel Detectors are position-sensitive proportional counters in which a complete integration between the gas amplification structure and the read-out electronics has been reached. Various generation of Application-Specific Integrated Circuit (ASIC) have been designed in deep submicron CMOS technology to realize a monolithic device which is at the same time the charge collecting electrode and the analog amplifying and charge measuring front-end electronics. The experimental response of a detector with 22060 pixels at 80 μm pitch to polarized and un-polarized X-ray radiation is shown and the application of this device for Astronomical X-ray Polarimetry discussed

  14. X-ray irradiation of yeast cells

    Science.gov (United States)

    Masini, Alessandra; Batani, Dimitri; Previdi, Fabio; Conti, Aldo; Pisani, Francesca; Botto, Cesare; Bortolotto, Fulvia; Torsiello, Flavia; Turcu, I. C. Edmond; Allott, Ric M.; Lisi, Nicola; Milani, Marziale; Costato, Michele; Pozzi, Achille; Koenig, Michel

    1997-10-01

    Saccharomyces Cerevisiae yeast cells were irradiated using the soft X-ray laser-plasma source at Rutherford Laboratory. The aim was to produce a selective damage of enzyme metabolic activity at the wall and membrane level (responsible for fermentation) without interfering with respiration (taking place in mitochondria) and with nuclear and DNA activity. The source was calibrated by PIN diodes and X-ray spectrometers. Teflon stripes were chosen as targets for the UV laser, emitting X-rays at about 0.9 keV, characterized by a very large decay exponent in biological matter. X-ray doses to the different cell compartments were calculated following a Lambert-Bouguet-Beer law. After irradiation, the selective damage to metabolic activity at the membrane level was measured by monitoring CO2 production with pressure silicon detectors. Preliminary results gave evidence of pressure reduction for irradiated samples and non-linear response to doses. Also metabolic oscillations were evidenced in cell suspensions and it was shown that X-ray irradiation changed the oscillation frequency.

  15. X-ray dosimetry of low energy using ZrO2 in Mammography

    International Nuclear Information System (INIS)

    Palacios P, L.L.; Rivera M, T.; Ortiz C, H.; Guzman, G.; Azorin, J.; Garcia H, M.

    2008-01-01

    This work reports the experimental results of the thermoluminescent dosemeters (DTL) of nano particles of zirconium dioxide (ZrO 2 ), prepared by the precipitation for X rays method of low energy that are used in mammography equipment. It is observed that the response of the TL curve for X rays of low energy coincides with the TL curve of ZrO 2 reported for conventional X rays. This curve presents two peaks, at 160 and 270 C respectively, being that of more intensity the second peak. (Author)

  16. X-raying with low dose irradiation

    International Nuclear Information System (INIS)

    Malevich, E.E.; Kisel, E.M.; Shpita, I.D.; Lazovsky, A.S.

    2001-01-01

    With the purpose of the improvement of diagnostics quality and reduction of beam load on a patient in modern x-ray devices pulse x-raying is applied. It is based on the using of radiation pulses with various frequencies of intervals between them instead of continuous radiation. At pulse x-raying with the net control the principle of filling of an interval is used, when the information about the image, received with the last pulse, get into memory and is displayed before occurrence of other pulse. It creates impression of the continuous image even at low frequency of pulses. Due to the unique concept of the simultaneous (double) control, all of 3 parameters, which define the quality of the image (pressure(voltage), force of a current and length of a pulse), are adjusted automatically at each pulse, thus optimum adaptation to varied thickness of object during dynamic researches occurs. At x-raying pulse the presence of a free interval from x-ray radiation between two pulses results in the decrease of a radiation dose. Pulsing occurs some times per one second with equal intervals between pulses. Thus, the degree of decrease irradiation dose depends on duration of a pause between pulses. On the screen the image of last pulse before occurrence of the following is kept and repeats. The principle of x-raying pulse was realized in system Grid Controlled Fluoroscopy by the firm 'Philips Medi zin Systeme'. In the x-ray tube of this system inclusion and de energizing of radiation occurs directly on a source. Electron cloud is broken off by the special grid, which is located between the cathode and the anode and operates as a barrier. Thus the tube continues to be energized. In usual devices for pulses formation is used generator pulsation system, which at increase and attenuation of a x-ray pulse results in occurrence of the increasing and fading radiation which are not participating in the formation of the image, but creating beam load on the patient and the personnel. Thus

  17. Neutron and X-ray emission studies in a low energy plasma focus

    Energy Technology Data Exchange (ETDEWEB)

    Zakaullah, M. [Quaid-i-Azam Univ., Islamabad (Pakistan). Dept. of Physics; Murtaza, G. [Quaid-i-Azam Univ., Islamabad (Pakistan). Dept. of Physics; Qamar, S. [Quaid-i-Azam Univ., Islamabad (Pakistan). Dept. of Physics; Ahmad, I. [Quaid-i-Azam Univ., Islamabad (Pakistan). Dept. of Physics; Beg, M.M. [Quaid-i-Azam Univ., Islamabad (Pakistan). Dept. of Physics

    1996-03-01

    In a low energy Mather-type plasma focus energized by a single 32 {mu}F capacitor, the X-ray and neutron emission is investigated using time-integrated and time-resolved detectors. The X-ray emission profile has a width (FWHM) of 40-50 ns. The neutron emission profile is broader compared to the X-ray emission profile and also delayed by 30-40 ns. To identify different regimes of X-ray emission, an X-ray pin-hole camera along with different absorption filters is employed. While the X-ray emission is high within a narrow pressure range of 2.0-2.5 mbar, the neutron emission is intense for a wider range of 1.0-4.5 mbar. The intense X-ray emission seems to originate from the axially moving shock wave. These results also indicate rather different production mechanisms for X-ray and neutron emission. Also on comparing the X-ray images with Al(2 {mu}m), Al(5 {mu}m), Al(9 {mu}m) filters, we find that the bulk of X-rays from the focus filament have energies less than 2 keV. (orig.).

  18. Solar X-ray Spectrometer (SOXS) Mission – Low Energy Payload

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... We present the first results from the 'Low Energy Detector' payload of 'Solar X-ray Spectrometer (SOXS)' mission, which was launched onboard GSAT-2 Indian spacecraft on 08 May 2003 by GSLV-D2 rocket to study the solar flares. The SOXS Low Energy Detector (SLD) payload was designed, developed ...

  19. Temporal characteristics and saturation effects of organic scintillators to low-energy X-rays

    International Nuclear Information System (INIS)

    Pronko, J.G.; Chase, L.F.

    1979-01-01

    Rise time, short and long term decay characteristics and possible saturation effects of the fluorescence of NE102, NE111, and doped NE111 organic scintillators were investigated using low-energy X-rays from a laser produced plasma. The laser system consisted of a pulsed Nd:glass facility operating at a pulse width of 0.2 ns at levels up to 10 J. The NE111 samples consisted of a matrix of scintillators with benzophenone, acetophenone, and piperidine each at concentrations of 0, 1, 2, 5, and 10 percent. The rise time of NE102 was measured at (640+-50) ps while that of both the doped and undoped NE111 was 2 ns) of irradiance used in this investigation. (Auth.)

  20. Compact alpha-excited sources of low energy x-rays

    International Nuclear Information System (INIS)

    Amlauer, K.; Tuohy, I.

    1976-01-01

    A discussion is given of the use of alpha emitting isotopes, such as 210 Po and 244 Cm, for the production of low energy x-rays (less than 5.9 keV). The design of currently available sources is described, and x-ray fluxes observed from various target materials are presented. Commercial applications of the alpha excitation technique are briefly discussed

  1. Development of low-energy X-ray spectrometry at the Laboratoire National Henri Becquerel

    International Nuclear Information System (INIS)

    Lepy, M.C.; Plagnard, J.

    2007-01-01

    In the frame of the French Metrology Institute, the Laboratoire National Henri Becquerel performs accurate characterization of semiconductor detectors that are in use in a number of applications. Their efficiency calibration, energy resolution and the detailed shape of their response function are parameters of interest for accurate processing of low-energy X-ray spectra to be applied to elements identification and fundamental research studies. The tools specifically developed for low-energy detectors calibration and characterization are described, from the use of radioactivity standard to the development of a tunable monochromatic X-ray source. (Author)

  2. Comparison of the results for quality implementation of low energy X rays

    International Nuclear Information System (INIS)

    Affonseca, M; Ochoa, R; Almeida, C.E. de; Peixoto, J.G.

    2001-01-01

    It describes the comparison of the results for qualities implementation of low energy X rays, using a pan tak tube, HF 160, which has tungsten white, beryllium window, is water-cooled and it has a 160 K B generator [es

  3. Solar X-ray Spectrometer (SOXS) Mission – Low Energy Payload ...

    Indian Academy of Sciences (India)

    Solar X-ray Spectrometer (SOXS)' mission, which was launched onboard GSAT-2 Indian spacecraft on 08 May 2003 by GSLV-D2 rocket to study the solar flares. The SOXS Low Energy Detector (SLD) payload was designed, developed and ...

  4. Low-Energy Microfocus X-Ray Source for Enhanced Testing Capability in the Stray Light Facility

    Science.gov (United States)

    Gaskin, Jessica; O'Dell, Stephen; Kolodziejczak, Jeff

    2015-01-01

    Research toward high-resolution, soft x-ray optics (mirrors and gratings) necessary for the next generation large x-ray observatories requires x-ray testing using a low-energy x-ray source with fine angular size (energy microfocus (approximately 0.1 mm spot) x-ray source from TruFocus Corporation that mates directly to the Stray Light Facility (SLF). MSFC X-ray Astronomy team members are internationally recognized for their expertise in the development, fabrication, and testing of grazing-incidence optics for x-ray telescopes. One of the key MSFC facilities for testing novel x-ray instrumentation is the SLF. This facility is an approximately 100-m-long beam line equipped with multiple x-ray sources and detectors. This new source adds to the already robust compliment of instrumentation, allowing MSFC to support additional internal and community x-ray testing needs.

  5. Superiority of Low Energy 160 KV X-Rays Compared to High Energy 6 MV X-Rays in Heavy Element Radiosensitization for Cancer Treatment

    Science.gov (United States)

    Lim, Sara N.; Pradhan, Anil K.; Nahar, Sultana N.; Barth, Rolf F.; Yang, Weilian; Nakkula, Robin J.; Palmer, Alycia; Turro, Claudia

    2013-06-01

    High energy X-rays in the MeV range are generally employed in conventional radiation therapy from linear accelerators (LINAC) to ensure sufficient penetration depths. However, lower energy X-rays in the keV range may be more effective when coupled with heavy element (high-Z or HZ) radiosensitizers. Numerical simulations of X-ray energy deposition for tumor phantoms sensitized with HZ radiosensitizers were performed using the Monte Carlo code Geant4. The results showed enhancement in energy deposition to radiosensitized phantoms relative to unsensitized phantoms for low energy X-rays in the keV range. In contrast, minimal enhancement was seen using high energy X-rays in the MeV range. Dose enhancement factors (DEFs) were computed and showed radiosensitization only in the low energy range nitrate, was initially used because it was 7x less toxic that an equivalent amount of carboplatin in vitro studies. This would allow us to separate the radiotoxic and the chemotoxic effects of HZ sensitizers. Results from this study showed a 10-fold dose dependent reduction in surviving fractions (SF) of radiosensitized cells treated with low energy 160 kV X-rays compared to those treated with 6 MV X-rays. This is in agreement with our simulations that show an increase in dose deposition in radiosensitized tumors for low energy X-rays. Due to unforeen in vivo toxicity, however, another in vitro study was performed using the commonly used, Pt-based chemotherapeutic drug carboplatin which confirmed earlier results. This lays the ground work for a planned in vivo study using F98 glioma bearing rats. This study demonstrates that while high energy X-rays are commonly used in cancer radiotherapy, low energy keV X-rays might be much more effective with HZ radiosensitization.

  6. Performance of room temperature mercuric iodide (HgI2) detectors in the ultra low energy x-ray region

    International Nuclear Information System (INIS)

    Dabrowski, A.J.; Iwanczyk, J.S.; Barton, J.B.; Huth, G.C.; Whited, R.; Ortale, C.; Economou, T.E.; Turkevich, A.L.

    1980-01-01

    Performance of room temperature mercuric iodide x-ray spectrometers has been recently improved through new fabrication techniques and further development of low noise associated electronic systems. This progress has extended the range of measurements to the ultra low energy x-ray region at room temperature. This paper reports the study of the effect of contact material on the performance of HgI 2 detectors in the low energy x-ray region

  7. GaAs low-energy X-ray radioluminescence nuclear battery

    Science.gov (United States)

    Zhang, Zheng-Rong; Liu, Yun-Peng; Tang, Xiao-Bin; Xu, Zhi-Heng; Yuan, Zi-Cheng; Liu, Kai; Chen, Wang

    2018-01-01

    The output properties of X-ray radioluminescence (RL) nuclear batteries with different phosphor layers were investigated by using low-energy X-ray. Results indicated that the values of electrical parameters increased as the X-ray energy increased, and the output power of nuclear battery with ZnS:Cu phosphor layer was greater than those of batteries with ZnS:Ag, (Zn,Cd)S:Cu or Y2O3:Eu phosphor layers under the same excitation conditions. To analyze the RL effects of the phosphor layers under X-ray excitation, we measured the RL spectra of the different phosphor layers. Their fluorescence emissions were absorbed by the GaAs device. In addition, considering luminescence utilization in batteries, we introduced an aluminum (Al) film between the X-ray emitter and phosphor layer. Al film is a high performance reflective material and can increase the fluorescence reaching the GaAs photovoltaic device. This approach significantly improved the output power of the battery.

  8. MiR-34a is up-regulated in response to low dose, low energy X-ray induced DNA damage in breast cells

    International Nuclear Information System (INIS)

    Stankevicins, Luiza; Almeida, Carlos Eduardo de; Moura Gallo, Claudia Vitoria de; Almeida da Silva, Ana Paula; Ventura dos Passos, Flavia; Santos Ferreira, Evelin dos; Menks Ribeiro, Maria Cecilia; G David, Mariano; J Pires, Evandro; Ferreira-Machado, Samara Cristina; Vassetzky, Yegor

    2013-01-01

    MicroRNAs are non-coding RNAs involved in the regulation of gene expression including DNA damage responses. Low doses of low energy X-ray radiation, similar to those used in mammographic exams, has been described to be genotoxic. In the present work we investigated the expression of miR-34a; a well described p53-regulated miRNA implicated in cell responses to X-ray irradiation at low doses. Non-cancerous breast cell line MCF-10A and cancerous T-47D and MCF-7 cell lines were submitted to a low-energy X-ray irradiation (ranging from 28–30 Kv) using a dose of 5 Gy. The expression level of miR-34a, let-7a and miR-21 was assessed by qRT-PCR at 4 and 24 hours post-irradiation. DNA damage was then measured by comet assay and micronuclei estimation in MCF-10A and MCF-7 cell lines, where an increase of miR-34a levels could be observed after irradiation. The rate of apoptotic cells was estimated by nuclear staining and fluorescence microscopy. These experiments were also performed at low doses (3; 12 and 48 mGy) in MCF-10A and MCF-7 cell lines. We have observed an increase in miR-34a expression 4 hours post-irradiation at 5 Gy in MCF-10A and MCF-7 cell lines while its level did not change in T-47D, a breast cancer cell line bearing non-functional p53. At low doses, miR-34a was up-regulated in non-tumoral MCF-10A to a higher extent as compared to MCF-7. MiR-34a levels decreased 24 hours post-irradiation. We have also observed DNA damage and apoptosis at low-energy X-ray irradiation at low doses and the high dose in MCF-10A and MCF-7 4 and 24 hours post-irradiation relative to the mock control. Low energy X-ray is able to promote DNA strand breaks and miR-34a might be involved in cell responses to low energy X-ray DNA damage. MiR-34a expression correlates with X-ray dose, time after irradiation and cell type. The present study reinforces the need of investigating consequences of low dose X-ray irradiation of breast cells

  9. Low-energy x-ray dosimetry studies (6 to 16 keV) at SSRL beamline 1-5

    International Nuclear Information System (INIS)

    Ipe, N.E.; Chatterji, S.; Fassograve, A.; Kase, K.R.; Seefred, R.; Bilski, P.; Soares, C.

    1997-01-01

    Synchrotron radiation facilities provide a unique opportunity for low-energy x-ray dosimetry studies because of the availability of monochromatic x-ray beams. Results of such studies performed at the Stanford Synchrotron Radiation Laboratory (SSRL) are described. Polish lithium fluoride thermoluminescent dosemeters (TLDs), MTS-N(LiF:Mg, Ti- 0.4 mm thick), MCP-N (LiF:Mg, Cu, P - 0.4 mm thick) were exposed free in air to monochromatic x-rays (6 - 16 keV). These exposures were monitored with an SSRL ionization chamber. The responses (counts/Gy) of MTS-N and MCP-N were generally found to increase with increasing energy. The response at 16 keV is about 3 and 4 times higher than the response at 6 keV for MTS-N and MCP-N, respectively. Irradiation at 6 keV indicates a fairly linear dose response for both type of TLDs over a dose range of 0.01 to 0.4 Gy. In addition there appears to be no significant difference in responses between irradiating the TLDs from the front and the back sides. The energy response of the PTW ionization chamber type 23342 relative to the SSRL ionization chamber is within ±4.5% between 6 and 16 keV. Both the TLDs and the PTW ionization chamber can also be used for beam dosimetry. copyright 1997 American Institute of Physics

  10. Large area APDs for low energy X-ray detection in intense magnetic fields

    International Nuclear Information System (INIS)

    Boucher, M.; Huot, O.; Knowles, P.E.; Ludhova, L.; Mulhauser, F.; Schaller, L.A.; Conde, C.A.N.; Santos, J.M.F. dos; Fernandes, L.M.P.; Veloso, J.F.C.A.; Kottmann, F.; Antognini, A.; Pohl, R.; Taqqu, D.

    2003-01-01

    An experiment to measure the energy difference between the 2S-2P atomic levels (Lamb shift) in muonic hydrogen is being prepared at PSI. Since the energy levels of muonic hydrogen are a factor of 186 more energetic than those of hydrogen, according to the ratio of reduced masses, the transitions lie in the soft X-ray region. The experiment needs long-lived muonic hydrogen in the 2S state. This is achieved by stopping a low energy muon beam in a small volume of low pressure hydrogen in a 5 T magnetic field. A pulsed beam from a tunable laser induces the 2S-2P transition and the 1.9 keV X-ray photons resulting from the 2P-1S deexcitation will be detected. Measuring the coincidences between the laser pulse and the X-ray as a function of the laser wavelength allows us to determine the Lamb shift. In this presentation we will discuss the perspectives of using large area avalanche photodiodes for the direct detection of the X-rays. Compared to gaseous detectors, they are more compact and simpler in operation. They are also insensitive to magnetic fields

  11. Large area APDs for low energy X-ray detection in intense magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Boucher, M.; Huot, O.; Knowles, P.E.; Ludhova, L.; Mulhauser, F. E-mail: francoise.mulhauser@unifr.ch; Schaller, L.A.; Conde, C.A.N.; Santos, J.M.F. dos; Fernandes, L.M.P.; Veloso, J.F.C.A.; Kottmann, F.; Antognini, A.; Pohl, R.; Taqqu, D

    2003-06-01

    An experiment to measure the energy difference between the 2S-2P atomic levels (Lamb shift) in muonic hydrogen is being prepared at PSI. Since the energy levels of muonic hydrogen are a factor of 186 more energetic than those of hydrogen, according to the ratio of reduced masses, the transitions lie in the soft X-ray region. The experiment needs long-lived muonic hydrogen in the 2S state. This is achieved by stopping a low energy muon beam in a small volume of low pressure hydrogen in a 5 T magnetic field. A pulsed beam from a tunable laser induces the 2S-2P transition and the 1.9 keV X-ray photons resulting from the 2P-1S deexcitation will be detected. Measuring the coincidences between the laser pulse and the X-ray as a function of the laser wavelength allows us to determine the Lamb shift. In this presentation we will discuss the perspectives of using large area avalanche photodiodes for the direct detection of the X-rays. Compared to gaseous detectors, they are more compact and simpler in operation. They are also insensitive to magnetic fields.

  12. Response of TLD-100 LiF dosimeters for X-rays of low energies

    International Nuclear Information System (INIS)

    Bonzi, E. V.; Mainardi, R. T.

    2011-10-01

    In diverse practical applications as the existent in radiological clinics, industrial facilities and research laboratories, the solid state dosimeters are used for the measure of the different types of ionizing radiations. At the present time dosimeters are manufactured with different types of materials that present thermoluminescent properties, to the effects of determining the absorbed radiation dose. Under these conditions, the radiation dose is determined integrated in all the range of energies of the beam of X-rays, since it assumes that the response of these dosimeters is lineal with the energy of the photons or radiant particles. Because interest exists in advancing in the development of a determination method in the way of the X-rays spectrum emitted by a tube of those used in diagnostic or therapy, we have measured the response of TLD-100 LiF dosimeters for low energies, minor at 60 keV, for a several group of these dosimeters. (Author)

  13. Low-energy X-ray and gamma spectrometry using silicon photodiodes

    International Nuclear Information System (INIS)

    Silva, Iran Jose Oliveira da

    2000-08-01

    The use of semiconductor detectors for radiation detection has increased in recent years due to advantages they present in comparison to other types of detectors. As the working principle of commercially available photodiodes is similar to the semiconductor detector, this study was carried out to evaluate the use of Si photodiodes for low energy x-ray and gamma spectrometry. The photodiodes investigated were SFH-205, SFH-206, BPW-34 and XRA-50 which have the following characteristics: active area of 0,07 cm 2 and 0,25 cm 2 , thickness of the depletion ranging from 100 to 200 μm and junction capacitance of 72 pF. The photodiode was polarized with a reverse bias and connected to a charge sensitive pre-amplifier, followed by a amplifier and multichannel pulse analyzer. Standard radiation source used in this experiment were 241 Am, 109 Cd, 57 Co and 133 Ba. The X-ray fluorescence of lead and silver were also measured through K- and L-lines. All the measurements were made with the photodiodes at room temperature.The results show that the responses of the photodiodes very linear by the x-ray energy and that the energy resolution in FWHM varied between 1.9 keV and 4.4 keV for peaks corresponding to 11.9 keV to 59 keV. The BPW-34 showed the best energy resolution and the lower dark current. The full-energy peak efficiency was also determined and it was observed that the peak efficiency decreases rapidly above 50 keV. The resolution and efficiency are similar to the values obtained with other semiconductor detectors, evidencing that the photodiodes used in that study can be used as a good performance detector for low energy X-ray and gamma spectrometry. (author)

  14. A new fully integrated X-ray irradiator system for dosimetric research

    International Nuclear Information System (INIS)

    Richter, D.; Mittelstraß, D.; Kreutzer, S.; Pintaske, R.; Dornich, K.; Fuchs, M.

    2016-01-01

    A fully housed X-ray irradiator was developed for use within lexsyg or Magnettech desktop equipment. The importance of hardening of the low energy photon radiation is discussed, its performance and feasibility is empirically shown and sustained by basic numerical simulations. Results of the latter for various materials are given for different X-ray source settings in order to provide estimates on the required setup for the irradiation of different geometries and materials. A Si-photodiode provides real-time monitoring of the X-ray-irradiator designed for use in dosimetric dating and other dosimetric application where irradiation of small samples or dosemeters is required. - Highlights: • Bench top X-ray irradiator provides variable dose-rates. • Simulation of low energy photon irradiation and hardening of X-ray. • Al-hardening for the irradiation of H_2O, BeO, Al_2O_3, quartz, feldspars and zircon. • Dosimetric dating equipment for luminescence and ESR.

  15. Establishment of standard low energy x-ray, radioprotection levels, for calibration of instruments

    International Nuclear Information System (INIS)

    Oliveira, Eliane Carmo

    1995-01-01

    Seven standard low energy X-rays fields were established, radioprotection level, at the Calibration Laboratory of IPEN. Five of the standard calibration qualities used at the National Physical Laboratory, England, with energies between 16 and 38 keV, and two recommended by the International Standard Organization, with energies of 33 and 48 keV, were reproduced. The calibration conditions, radiotherapy level, from 14 to 21 keV, were also verified. Different portable radiation monitors as ionization chambers and Geiger-Mueller detectors were studied in relation to their energy dependence. (author)

  16. X-ray evidence of low-energy photon therapy for cervical lordosis restoration and radial head spur healing

    Science.gov (United States)

    Fitz-Ritson, Donald; Filonenko, Natalia; Salansky, Norman M.

    1994-09-01

    X rays were used for low energy photon therapy (LEPT) efficacy assessment for cervical lordosis restoration and radial head spur healing. Two cases, their evaluation, and treatment are discussed along with the follow-up results.

  17. Characterization of low energy X-rays beams with an extrapolation chamber

    International Nuclear Information System (INIS)

    Bastos, Fernanda Martins

    2015-01-01

    In laboratories involving Radiological Protection practices, it is usual to use reference radiations for calibrating dosimeters and to study their response in terms of energy dependence. The International Organization for Standardization (ISO) established four series of reference X-rays beams in the ISO- 4037 standard: the L and H series, as low and high air Kerma rates, respectively, the N series of narrow spectrum and W series of wide spectrum. The X-rays beams with tube potential below 30 kV, called 'low energy beams' are, in most cases, critical as far as the determination of their parameters for characterization purpose, such as half-value layer. Extrapolation chambers are parallel plate ionization chambers that have one mobile electrode that allows variation of the air volume in its interior. These detectors are commonly used to measure the quantity Absorbed Dose, mostly in the medium surface, based on the extrapolation of the linear ionization current as a function of the distance between the electrodes. In this work, a characterization of a model 23392 PTW extrapolation chamber was done in low energy X-rays beams of the ISO- 4037 standard, by determining the polarization voltage range through the saturation curves and the value of the true null electrode spacing. In addition, the metrological reliability of the extrapolation chamber was studied with measurements of the value of leakage current and repeatability tests; limit values were established for the proper use of the chamber. The PTW23392 extrapolation chamber was calibrated in terms of air Kerma in some of the ISO radiation series of low energy; the traceability of the chamber to the National Standard Dosimeter was established. The study of energy dependency of the extrapolation chamber and the assessment of the uncertainties related to the calibration coefficient were also done; it was shown that the energy dependence was reduced to 4% when the extrapolation technique was used. Finally, the first

  18. Investigation of multilayered nanocomposites as low energy X-Rays attenuators

    International Nuclear Information System (INIS)

    Silva, Liliane; Batista, Adriana S.M.; Nascimento, Jefferson P.; Furtado, Clascídia A.; Faria, Luiz O.

    2017-01-01

    The development of radiation attenuating materials has application in radioprotection and conditioning of short-lived waste. Polymeric materials can serve as a matrix for the dispersion of nanomaterials with good attenuation features, resulting in lightweight, conformable, flexible and easy-to-process materials. Thus, some well-known shielding materials could be used in low proportion for the formation of new materials. On the other hand, nanostructured carbon materials, such as graphene oxide (GO) and carbon nanotubes (NTCs), have been reported recently to show enhanced attenuation properties. In this sense, polymeric matrixes provide the necessary flexibility for use in various applications that require molding. For the present work, poly(vinylidene fluoride) [PVDF] homopolymers and its fluorinated copolymers were filled with nanosized metallic and graphene oxides in order to produce nanocomposites with increased low energy X-ray attenuation efficiency. Film samples of PVDF/reduced Graphene Oxide [PVDF/rGO] and Poly(vinylidene fluoride – tryfluorethylene)/Barium Oxide [P(VDF-TrFE)/BaO] were synthesized. In a second step, the samples were then sandwiched between Kapton® layers and exposed to X-rays source (8.5 keV). The samples were characterized with Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS). The attenuation coefficient was evaluated and compared with the attenuation of the individual constituents. It was observed an increase in the linear attenuation coefficient of the layered materials, justifying further investigation of these nanostructured composites as X-ray or gamma radiation attenuators. (author)

  19. Hard x-ray to low energy gamma ray spectrum of the Crab Nebula

    International Nuclear Information System (INIS)

    Jung, G.V.

    1986-01-01

    The spectrum of the Crab Nebula has been determined in the energy range 10 keV to 5 MeV from the data of the UCSD/MIT Hard-X-ray and Low Energy Gamma Ray Experiment on the first High Energy Astronomy Observatory, HEAO-1. The x-ray to γ-ray portion of the continuous emission from the Crab is indicative of the electron spectrum, its transport through the nebula, and the physical conditions near the shocked interface between the nebular region and the wind which is the physical link between the nebula and the pulsar, NP0532. The power-law dependence of the spectrum found in the lower-energy decade of this observation (10 to 100 keV) is not continued without modification to higher energies. Evidence for this has been accumulating from previous observations in the γ-ray ranges of 1-10 MeV and above 35 MeV. The observations on which this dissertation is based further characterize the spectral change in the 100 keV to 1 MeV region. These observations provide a crucial connection between the x-ray and γ-ray spectrum of the non-pulsed emission of the Crab Nebula. The continuity of this spectrum suggests that the emission mechanism responsible for the non-pulsed γ-rays observed above 35 MeV is of the same origin as the emission at lower energies, i.e. that of synchrotron radiation in the magnetic field of the nebula

  20. Investigation of multilayered nanocomposites as low energy X-Rays attenuators

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Liliane; Batista, Adriana S.M.; Nascimento, Jefferson P.; Furtado, Clascídia A.; Faria, Luiz O., E-mail: asfisica@gmail.com, E-mail: adriananuclear@yahoo.com.br, E-mail: farialo@cdtn.br, E-mail: nascimentopatricio@yahoo.com.br, E-mail: clas@cdtn.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil); Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2017-11-01

    The development of radiation attenuating materials has application in radioprotection and conditioning of short-lived waste. Polymeric materials can serve as a matrix for the dispersion of nanomaterials with good attenuation features, resulting in lightweight, conformable, flexible and easy-to-process materials. Thus, some well-known shielding materials could be used in low proportion for the formation of new materials. On the other hand, nanostructured carbon materials, such as graphene oxide (GO) and carbon nanotubes (NTCs), have been reported recently to show enhanced attenuation properties. In this sense, polymeric matrixes provide the necessary flexibility for use in various applications that require molding. For the present work, poly(vinylidene fluoride) [PVDF] homopolymers and its fluorinated copolymers were filled with nanosized metallic and graphene oxides in order to produce nanocomposites with increased low energy X-ray attenuation efficiency. Film samples of PVDF/reduced Graphene Oxide [PVDF/rGO] and Poly(vinylidene fluoride – tryfluorethylene)/Barium Oxide [P(VDF-TrFE)/BaO] were synthesized. In a second step, the samples were then sandwiched between Kapton® layers and exposed to X-rays source (8.5 keV). The samples were characterized with Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS). The attenuation coefficient was evaluated and compared with the attenuation of the individual constituents. It was observed an increase in the linear attenuation coefficient of the layered materials, justifying further investigation of these nanostructured composites as X-ray or gamma radiation attenuators. (author)

  1. X-ray Spectral Survey of WGACAT Quasars, II: Optical and Radio Properties of Quasars with Low Energy X-ray Cut-offs

    OpenAIRE

    Elvis, Martin; Fiore, Fabrizio; Giommi, Paolo; Padovani, Paolo

    1997-01-01

    We have selected quasars with X-ray colors suggestive of a low energy cut-off, from the ROSAT PSPC pointed archive. We examine the radio and optical properties of these 13 quasars. Five out of the seven quasars with good optical spectra show associated optical absorption lines, with two having high delta-v candidate systems. Two other cut-off quasars show reddening associated with the quasar. We conclude that absorption is highly likely to be the cause of the X-ray cut-offs, and that the abso...

  2. Contribution to the study of low-energy X-ray-induced degradations on the oxide-silicon interfacial transition layer of MOS structures

    International Nuclear Information System (INIS)

    Boukabache, Ali

    1983-01-01

    The Si-SiO_2 interface is considered as a transition layer. Its thickness is typically about 10 A. It contains traps which exchange charges with silicon by a tunneling mechanism. Its influence on MOS capacitor, gate-controlled diode and MOS transistor is analyzed. Long channel MOST's (P-Substrate) are irradiated with low energy X-ray (between 0 and 240 Krads) in order to validate the model. Capacitance, recombination velocity and 1/f noise measurements indicate that the X- ray induce traps distributed in space and in energy. These traps provoke a decrease in mobility. Additionally, X-rays create a fixed oxide charge which induce a shift in the characteristics of MOS structures. Finally, under irradiation the behaviour of the gate-controlled diode and the MOS capacitor are in accordance with theoretical model of the interfacial layer. The overall noise behaviour cannot be explained by existing theoretical models. (author) [fr

  3. Clinical implementation of a low energy x-ray therapy device in the treatment of breast cancer

    International Nuclear Information System (INIS)

    Haworth, A.; University of Western Australia, WA; Joseph, D.; Lanzon, P.; Caswell, N.; Ebert, M.; University of Western Asutralia, WA

    2001-01-01

    Full text: A low energy device producing x-rays of maximum operating potential of 50kV is used to treat primary breast tumours intraoperatively. In pathologically favourable cases, the treatment replaces conventional external beam irradiation. For patients at greater risk of local recurrence, the treatment replaces conventional 'boost' therapy. The dosimetry of the device will be described in a companion paper. QA tests prior to irradiation include: output calibration/verification; isotropy verification and external radiation monitor (the secondary beam termination device) functionality. The internal radiation monitor count (similar to setting monitor units on a linac) for a prescribed dose is calculated from tables of measured depth dose and applicator factors. The spherical applicator which best suits the size of the excised tumour is lightly sutured into position maintaining as much distance between the skin surface as possible to minimise skin erythema. Radiation protection is achieved with the use of portable lead shields and tungsten impregnated silicon drapes. Patients entered into a TROG randomised clinical trial comparing intraoperative with conventional postoperative radiotherapy after conservative breast surgery for women with early stage breast cancer will be studied in collaboration with the CRC/University College London, Cancer Trials Centre (UK) to record the effects of local tumour control, cosmesis, patient satisfaction and health economics. QA tests take approximately 15 minutes to perform and a treatment prescription of 5Gy at 1cm depth with a 5cm applicator would take approximately 30 minutes. A low energy x-ray device may be used intraoperatively in selected cases to replace conventional radiotherapy minimising the inconvenience for patients and reducing waiting lists on treatment machines. Copyright (2001) Australasian College of Physical Scientists and Engineers in Medicine

  4. Energy response of graphite-mixed magnesium borate TLDs to low energy x-rays

    DEFF Research Database (Denmark)

    Pelliccioni, M.; Prokic, M.; Esposito, A.

    1991-01-01

    Graphite-mixed sintered magnesium borate TL dosemeters are attractive for beta/gamma dosimetry because they combine a low energy dependence to beta-rays with near tissue or air equivalence to photon irradiations and a high sensitivity. In this paper results from the experimental measurements...

  5. Effect of x-ray irradiated rat fetus mandible

    International Nuclear Information System (INIS)

    Han, Chang Gun; You, Dong Soo

    1978-01-01

    The effect of irradiation of x-ray to developing rat mandible in the gestation stage was focused on the study of mandible development and the side effect of x-ray irradiation. The author studied the effect of x-ray irradiation with the gestated rat and their offsprings. 100 rads, 200 rads, 300 rads and 400 rads of x-ray was irradiated in regular order schematically at the lower left abdomen of gestated rat. 18 1/2 days after conception, their offsprings were sacrificed and examined their developing mandible with histological findings. The results were as followed. 1. In the 100-200 rads irradiated rat offsprings, bony trabeclulation was revealed irregular shape. In combine with this finding, osteoblast and fibroblast were appeared shrunken of their nucleus and location of eccentric position. 2. In the 300-400 rads irradiated rat offsprings, decrease of fibroblast and osteoblast appearance in the periosteum were prominently observed and empty lacunae were frequently appeared in their bone matrix. 3. The advent of osteoclast and resorption of cortical bone were appeared in proportion to increasing of x-ray irradiation.

  6. Low-energy X-ray treatment of basal-cell carcinomas on and around eyelids

    International Nuclear Information System (INIS)

    Hendel, B.

    1982-01-01

    The results and experience gained with soft-radiation therapy of eyelid basal-cell carcinomas at the Dermatological University Clinic of Munich are presented in this thesis which supplies statistical data specific of patients and basilomas, discusses the irradiation technique used and compares it with those applied in other medical centres. Next it submits the curative results of eyelid basiloma irradiation comparing these with those obtained in other clinics. A separate chapter is dedicated to relapses showing i.a. possible recidivation causes followed by a presentation of each relapse case. The thesis concludes with a comparison of X-ray therapy and its results in the treatment of eyelid basal-cell carcinomas with other therapeutical methods and their results. (orig./MG) [de

  7. Impact of X-ray irradiation on PMMA thin films

    Energy Technology Data Exchange (ETDEWEB)

    Iqbal, Saman, E-mail: saman.khan343@gmail.com [Physics Department, University of Engineering and Technology, Lahore (Pakistan); Rafique, Muhammad Shahid [Physics Department, University of Engineering and Technology, Lahore (Pakistan); Anjum, Safia [Physics Department, Lahore College for Woman University, Lahore (Pakistan); Hayat, Asma [Physics Department, University of Engineering and Technology, Lahore (Pakistan); Iqbal, Nida [Faculty of Biomedical Engineering and Health Science, Universiti Teknologi Malaysia (UTM) (Malaysia)

    2012-10-15

    Highlights: Black-Right-Pointing-Pointer PMMA thin films were deposited at 300 Degree-Sign C and 500 Degree-Sign C using PLD technique. Black-Right-Pointing-Pointer These films were irradiated with different fluence of laser produced X-rays. Black-Right-Pointing-Pointer Irradiation affects the ordered packing as well as surface morphology of film. Black-Right-Pointing-Pointer Hardness of film decreases up to certain value of X-ray fluence. Black-Right-Pointing-Pointer Absorption in UV-visible range exhibits a non linear behavior. - Abstract: The objective of this project is to explore the effect of X-ray irradiation of thin polymeric films deposited at various substrate temperatures. pulsed laser deposition (PLD) technique is used for the deposition of PMMA thin films on glass substrate at 300 Degree-Sign C and 500 Degree-Sign C. These films have been irradiated with various X-rays fluences ranging from 2.56 to 5.76 mJ cm{sup -2}. Characterization of the films (before and after the irradiation) is done with help of X-ray Diffractrometer, Optical Microscope, Vickers hardness tester and UV-vis spectroscopy techniques. From XRD data, it is revealed that ordered packing has been improved for the films deposited at 300 Degree-Sign C. However after irradiation the films exhibited the amorphous behavior regardless of the X-ray fluence. Film deposited at 500 Degree-Sign C shows amorphous structure before and after irradiation. Hardness and particle size of thin film have also increased with the increasing substrate temperature. However, the irradiation has reverse effect i.e. the particle size as well as the hardness has reduced. Irradiation has also enhanced the absorption in the UV-visible region.

  8. Impact of X-ray irradiation on PMMA thin films

    International Nuclear Information System (INIS)

    Iqbal, Saman; Rafique, Muhammad Shahid; Anjum, Safia; Hayat, Asma; Iqbal, Nida

    2012-01-01

    Highlights: ► PMMA thin films were deposited at 300 °C and 500 °C using PLD technique. ► These films were irradiated with different fluence of laser produced X-rays. ► Irradiation affects the ordered packing as well as surface morphology of film. ► Hardness of film decreases up to certain value of X-ray fluence. ► Absorption in UV–visible range exhibits a non linear behavior. - Abstract: The objective of this project is to explore the effect of X-ray irradiation of thin polymeric films deposited at various substrate temperatures. pulsed laser deposition (PLD) technique is used for the deposition of PMMA thin films on glass substrate at 300 °C and 500 °C. These films have been irradiated with various X-rays fluences ranging from 2.56 to 5.76 mJ cm −2 . Characterization of the films (before and after the irradiation) is done with help of X-ray Diffractrometer, Optical Microscope, Vickers hardness tester and UV–vis spectroscopy techniques. From XRD data, it is revealed that ordered packing has been improved for the films deposited at 300 °C. However after irradiation the films exhibited the amorphous behavior regardless of the X-ray fluence. Film deposited at 500 °C shows amorphous structure before and after irradiation. Hardness and particle size of thin film have also increased with the increasing substrate temperature. However, the irradiation has reverse effect i.e. the particle size as well as the hardness has reduced. Irradiation has also enhanced the absorption in the UV–visible region.

  9. Quality control of X-ray irradiator by biological markers

    International Nuclear Information System (INIS)

    Miura, Miwa; Lukmanul Hakkim, F.; Yoshida, Masahiro; Matsuda, Naoki; Morita, Naoko

    2011-01-01

    The exposure of animals or cultured cells to radiation is the essential and common step in experimental researches to elucidate biological effects of radiation. When an X-ray generator is used as a radiation source, physical parameters including dose, dose rate, and the energy spectrum of X-ray play crucial roles in biological outcome. Therefore, those parameters are the important points to be checked in quality control and to be carefully considered in advance to the irradiation to obtain the accurate and reproductive results. Here we measured radiation dose emitted from the X-ray irradiator for research purposes by using clonogenic survival of cultured mammalian cells as a biological marker in parallel with physical dosimetry. The results drawn from both methods exhibited good consistency in the dose distribution on the irradiation stage. Furthermore, the close relationship was observed between cell survival and the photon energy spectrum by using different filter components. These results suggest that biological dosimetry is applicable to quality control of X-ray irradiator in adjunct to physical dosimetry and that it possibly helps better understanding of the optimal irradiating condition by X-ray users in life-science field. (author)

  10. Sphere of equivalence--a novel target volume concept for intraoperative radiotherapy using low-energy X rays.

    Science.gov (United States)

    Herskind, Carsten; Griebel, Jürgen; Kraus-Tiefenbacher, Uta; Wenz, Frederik

    2008-12-01

    Accelerated partial breast radiotherapy with low-energy photons from a miniature X-ray machine is undergoing a randomized clinical trial (Targeted Intra-operative Radiation Therapy [TARGIT]) in a selected subgroup of patients treated with breast-conserving surgery. The steep radial dose gradient implies reduced tumor cell control with increasing depth in the tumor bed. The purpose was to compare the expected risk of local recurrence in this nonuniform radiation field with that after conventional external beam radiotherapy. The relative biologic effectiveness of low-energy photons was modeled using the linear-quadratic formalism including repair of sublethal lesions during protracted irradiation. Doses of 50-kV X-rays (Intrabeam) were converted to equivalent fractionated doses, EQD2, as function of depth in the tumor bed. The probability of local control was estimated using a logistic dose-response relationship fitted to clinical data from fractionated radiotherapy. The model calculations show that, for a cohort of patients, the increase in local control in the high-dose region near the applicator partly compensates the reduction of local control at greater distances. Thus a "sphere of equivalence" exists within which the risk of recurrence is equal to that after external fractionated radiotherapy. The spatial distribution of recurrences inside this sphere will be different from that after conventional radiotherapy. A novel target volume concept is presented here. The incidence of recurrences arising in the tumor bed around the excised tumor will test the validity of this concept and the efficacy of the treatment. Recurrences elsewhere will have implications for the rationale of TARGIT.

  11. Quickness analysis and realization of DDC316 in low-energy X-rays detection acquisition system

    International Nuclear Information System (INIS)

    Gao Fuqiang; Zhang Yaqiong; Zhang Xiaojiao

    2011-01-01

    According to the performance requirements of Industry low-energy X-rays Detection acquisition sys- tem, through analyzing the characteristics of low-energy X-rays, DDC316 and series of other ADC chips, to research the impact on systems rapidity when using DDC316 chip to achieve signal amplifier and A/D conversion the detection system based on FPGA technique, choose series of Cyclone EPIC3T144C8 as the main control chip which produced by Altera company, in order to improve the rapidity of the system. (authors)

  12. Methodology for calibration of ionization chambers for X-ray of low energy in absorbed dose to water

    International Nuclear Information System (INIS)

    Oliveira, C.T.; Vivolo, V.; Potiens, M.P.A.

    2015-01-01

    The beams of low energy X-ray (10 to 150 kV) are used in several places in the world to treat a wide variety of surface disorders, and between these malignancies. As in Brazil, at this moment, there is no calibration laboratory providing the control service or calibration of parallel plate ionization chambers, the aim of this project was to establish a methodology for calibration of this kind of ionization chambers at low energy X-ray beams in terms of absorbed dose to water using simulators in the LCI. (author)

  13. 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

  14. Low-energy d-d excitations in MnO studied by resonant x-ray fluorescence spectroscopy

    International Nuclear Information System (INIS)

    Butorin, S.M.; Guo, J.; Magnuson, M.

    1997-01-01

    Resonant soft X-ray emission spectroscopy has been demonstrated to possess interesting abilities for studies of electronic structure in various systems, such as symmetry probing, alignment and polarization dependence, sensitivity to channel interference, etc. In the present abstract the authors focus on the feasibility of resonant soft X-ray emission to probe low energy excitations by means of resonant electronic X-ray Raman scattering. Resonant X-ray emission can be regarded as an inelastic scattering process where a system in the ground state is transferred to a low excited state via a virtual core excitation. The energy closeness to a core excitation of the exciting radiation enhances the (generally) low probability for inelastic scattering at these wavelengths. Therefore soft X-ray emission spectroscopy (in resonant electronic Raman mode) can be used to study low energy d-d excitations in transition metal systems. The involvement of the intermediate core state allows one to use the selection rules of X-ray emission, and the appearance of the elastically scattered line in the spectra provides the reference to the ground state

  15. Low-energy d-d excitations in MnO studied by resonant x-ray fluorescence spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Butorin, S.M.; Guo, J.; Magnuson, M. [Uppsala Univ. (Sweden)] [and others

    1997-04-01

    Resonant soft X-ray emission spectroscopy has been demonstrated to possess interesting abilities for studies of electronic structure in various systems, such as symmetry probing, alignment and polarization dependence, sensitivity to channel interference, etc. In the present abstract the authors focus on the feasibility of resonant soft X-ray emission to probe low energy excitations by means of resonant electronic X-ray Raman scattering. Resonant X-ray emission can be regarded as an inelastic scattering process where a system in the ground state is transferred to a low excited state via a virtual core excitation. The energy closeness to a core excitation of the exciting radiation enhances the (generally) low probability for inelastic scattering at these wavelengths. Therefore soft X-ray emission spectroscopy (in resonant electronic Raman mode) can be used to study low energy d-d excitations in transition metal systems. The involvement of the intermediate core state allows one to use the selection rules of X-ray emission, and the appearance of the elastically scattered line in the spectra provides the reference to the ground state.

  16. Performance test for implantation of a primary standard of low energy X-ray beams

    International Nuclear Information System (INIS)

    Cardoso, Ricardo de Souza; Bossio, Francisco; Peixoto, Jose Guilherme P.

    2005-01-01

    The implementation of a standard laboratory of calibration chambers that will serve to radiotherapy activities, radiodiagnosis and radioprotection, depends on the knowledge of physical and dosimetric parameters that characterize the quality of the radiation beam. With the aim of verifying the reliability of the ionizing free-air chamber with variable volume manufactured by Victoreen Instruments, model 481, as a primary standard, a study of the performance of the chamber to x-rays qualities of low energy was developed in this work. These qualities are the ones recommended by 'Bureau International des Poids et Mesures' - BIPM, for daily routine of the calibration service performed by the 'Laboratorio Nacional de Metrologia das Radiacoes Ionizantes - LNMRI/IRD, for calibration of this secondary standard chambers that serve to the control in hospitals, clinics and industries. The results obtained at the present work show that the Victoreen chamber model 481 behaves as a primary standard, being easy to handle and having simple mechanical construction, and showing an expanded uncertainty equal to 0,26%, regarding the quality of the radiation beam of 30 kV. However, some of the equipment used at the present study need to be submitted to a strict routine calibration, in order for the laboratory to be in accordance with the recommendations of the standard ABNT -NBR ISO/IEC 17025 (2003). (author)

  17. Study of energy dependence of a extrapolation chamber in low energy X-rays beams

    International Nuclear Information System (INIS)

    Bastos, Fernanda M.; Silva, Teogenes A. da

    2014-01-01

    This work was with the main objective to study the energy dependence of extrapolation chamber in low energy X-rays to determine the value of the uncertainty associated with the variation of the incident radiation energy in the measures in which it is used. For studying the dependence of energy, were conducted comparative ionization current measurements between the extrapolation chamber and two ionization chambers: a chamber mammography, RC6M model, Radcal with energy dependence less than 5% and a 2575 model radioprotection chamber NE Technology; both chambers have very thin windows, allowing its application in low power beams. Measurements were made at four different depths of 1.0 to 4.0 mm extrapolation chamber, 1.0 mm interval, for each reference radiation. The study showed that there is a variable energy dependence on the volume of the extrapolation chamber. In other analysis, it is concluded that the energy dependence of extrapolation chamber becomes smaller when using the slope of the ionization current versus depth for the different radiation reference; this shows that the extrapolation technique, used for the absorbed dose calculation, reduces the uncertainty associated with the influence of the response variation with energy radiation

  18. Degradation of organophosphorus compounds by X-ray irradiation

    International Nuclear Information System (INIS)

    Trebse, P.; Arcon, I.

    2002-01-01

    Complete text of publication follows. Our research presented in this contribution aims to elucidate the degradation mechanisms of organophosphate pesticides as organic pollutants by X-ray irradiation. Diazinon, one of the most widely used pesticides in Slovenia, has been chosen as a model compound for the study of radiation induced degradation of organophosphorus pesticides. Recent studies have shown that the degradation of the pesticide at normal conditions (room temperature, exposure to daylight) is strongly enhanced when the pesticide is exposed to UV light (Hg lamp, λ=254 nm, XeCl excimer laser, λ=308 nm). In our study we irradiated the pesticide in aqueous media with a white x-ray beam from a conventional x-ray source. Mo X-ray tube operating at the high voltage of 55 kV and a current of 45 mA was used. The flux of the continuous X-ray beam was stabilized within 1%. Saturated water solution of the pesticide (volume: 4mL, conc. of 40 mg L -1 ) was inserted in 1 cm long lucite cell with 1 mm thick lucite windows. The whole volume of the solution in the cell was exposed to the unfiltered X-ray beam. The dose rate on the sample was about 1 mGy/s. Different irradiation times between 30 min to 120 min were chosen to study the dependence of the pesticide decomposition with the absorbed dose. Solid phase extraction was employed for sample extraction from the solution, and gas chromatography was used for the identification and quantification of the compounds. The results show that the concentration of the pesticide in the solution decreases exponentially with the exposure time, i.e. with the absorbed dose. At irradiation conditions described above, the time constant of the exponential decrease was 74 min

  19. A new detector system for low energy X-ray fluorescence coupled with soft X-ray microscopy: First tests and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Gianoncelli, Alessandra, E-mail: alessandra.gianoncelli@elettra.eu [Elettra-Sincrotrone Trieste S.C.p.A., Strada Statale SS14, km 163.5, Basovizza 34149 (Italy); Bufon, Jernej [INFN Trieste, Padriciano 99, Trieste 34149 (Italy); Elettra-Sincrotrone Trieste S.C.p.A., Strada Statale SS14, km 163.5, Basovizza 34149 (Italy); University of Trieste, Piazzale Europa 1, Trieste 34127 (Italy); Ahangarianabhari, Mahdi [Politecnico di Milano, Via Anzani 42, Como 22100 (Italy); INFN Milano, Via Celoria 16, Milano 20133 (Italy); Altissimo, Matteo [Elettra-Sincrotrone Trieste S.C.p.A., Strada Statale SS14, km 163.5, Basovizza 34149 (Italy); Bellutti, Pierluigi [Fondazione Bruno Kessler, Via Sommarive 18, Trento 38123 (Italy); Bertuccio, Giuseppe [Politecnico di Milano, Via Anzani 42, Como 22100 (Italy); INFN Milano, Via Celoria 16, Milano 20133 (Italy); Borghes, Roberto [Elettra-Sincrotrone Trieste S.C.p.A., Strada Statale SS14, km 163.5, Basovizza 34149 (Italy); Carrato, Sergio [University of Trieste, Piazzale Europa 1, Trieste 34127 (Italy); Cautero, Giuseppe [Elettra-Sincrotrone Trieste S.C.p.A., Strada Statale SS14, km 163.5, Basovizza 34149 (Italy); INFN Trieste, Padriciano 99, Trieste 34149 (Italy); Fabiani, Sergio [INFN Trieste, Padriciano 99, Trieste 34149 (Italy); Giacomini, Gabriele [Fondazione Bruno Kessler, Via Sommarive 18, Trento 38123 (Italy); Giuressi, Dario [Elettra-Sincrotrone Trieste S.C.p.A., Strada Statale SS14, km 163.5, Basovizza 34149 (Italy); INFN Trieste, Padriciano 99, Trieste 34149 (Italy); Kourousias, George [Elettra-Sincrotrone Trieste S.C.p.A., Strada Statale SS14, km 163.5, Basovizza 34149 (Italy); Menk, Ralf Hendrik [Elettra-Sincrotrone Trieste S.C.p.A., Strada Statale SS14, km 163.5, Basovizza 34149 (Italy); INFN Trieste, Padriciano 99, Trieste 34149 (Italy); Picciotto, Antonino; Piemonte, Claudio [Fondazione Bruno Kessler, Via Sommarive 18, Trento 38123 (Italy); Rachevski, Alexandre [INFN Trieste, Padriciano 99, Trieste 34149 (Italy); and others

    2016-04-21

    The last decades have witnessed substantial efforts in the development of several detector technologies for X-ray fluorescence (XRF) applications. In spite of the increasing trend towards performing, cost-effective and reliable XRF systems, detectors for soft X-ray spectroscopy still remain a challenge, requiring further study, engineering and customization in order to yield effective and efficient systems. In this paper we report on the development, first characterization and tests of a novel multielement detector system based on low leakage current silicon drift detectors (SDD) coupled to ultra low noise custom CMOS preamplifiers for synchrotron-based low energy XRF. This new system exhibits the potential for improving the count rate by at least an order of magnitude resulting in ten-fold shorter dwell time at an energy resolution similar to that of single element silicon drift detectors.

  20. Low-energy x-ray dosimetry studies (7 to 17.5 keV) with synchroton radiation

    International Nuclear Information System (INIS)

    Ipe, N.E.; Bellamy, H.; Flood, J.R.

    1995-06-01

    Unique properties of synchrotron radiation (SR), such as its high intensity, brightness, polarization, and broad spectral distribution (extending from x-ray to infra-red wavelengths) make it an attractive light source for numerous experiments. As SR facilities are rapidly being built all over the world, they introduce the need for low-energy x-ray dosemeters because of the potential radiation exposure to experimenters. However, they also provide a unique opportunity for low-energy x-ray dosimetry studies because of the availability of monochromatic x-ray beams. Results of such studies performed at the Stanford Synchrotron Radiation Laboratory are described. Lithium fluoride TLDs (TLD-100) of varying thicknesses (0.015 to 0.08 cm) were exposed free in air to monochromatic x-rays (7 to 17.5 keV). These exposures were monitored with ionization chambers. The response (nC/Gy) was found to increase with increasing TLD thickness and with increasing beam energy. A steeper increase in response with increasing energy was observed with the thicker TLDs. The responses at 7 and 17.5 keV were within a factor of 2.3 and 5.2 for the 0.015 and 0.08 cm-thick TLDs, respectively. The effects of narrow (beam size smaller than the dosemeter) and broad (beam size larger than the dosemeter) beams on the response of the TLDs are also reported

  1. 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

  2. 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.

  3. 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.

  4. 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

  5. High resolution low energy X-ray microradiography using a CCD camera

    Czech Academy of Sciences Publication Activity Database

    Touš, J.; Horodysky, P.; Blažek, K.; Nikl, Martin; Mareš, Jiří A.

    2011-01-01

    Roč. 6, C1 (2011), s. 1-5 ISSN 1748-0221 R&D Projects: GA AV ČR KAN300100802 Institutional research plan: CEZ:AV0Z10100521 Keywords : X-ray radiography and digital radiography * inspection with x-rays * detection of defects Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.869, year: 2011

  6. X-ray yields by low energy heavy ion excitation in alkali halide solid targets

    International Nuclear Information System (INIS)

    Kurup, M.B.; Prasad, K.G.; Sharma, R.P.

    1981-01-01

    Solid targets of the alkali halides KCl, NaCl and KBr are bombarded with ion beams of 35 Cl + , 40 Ar + and 63 Cu + in the energy range 165 keV to 320 keV. The MO and characteristic K X-ray yields resulting from the ion-atom collision have been systematically studied. Both MO and Cl K X-ray yields are enhanced by factors 3.5 and 2 respectively in KCl targets as compared to that in NaCl when bombarded with either Cl + or Ar + projectiles. An intercomparison of MO and K X-ray yields for a given projectile-target combination has shown that the latter increases ten times faster than the former as the energy of the projectile is increased from 165 to 320 keV indicating a correspondingly stronger velocity dependence of the K X-ray production process. The X-ray yields observed in the symmetric Cl-Cl collision are identical to those observed in the asymmetric Ar-Cl collision for the same projectile velocities in both KCl and NaCl targets. It is inferred that the multiple ionization of the projectile resulting in an increase in the binding energy of its inner shells offsets the expected enhancement in the X-ray yields in a symmetric collision. The same projectiles, Ar or Cl, incident on KBr targets have produced only Br L X-rays. Using substantially heavier projectiles than the target atoms (Na, K and Cl), like 63 Cu + ions, the inner shell excitation by recoiling atoms is shown. (orig.)

  7. Application of a low energy x-ray spectrometer to analyses of suspended air particulate matter

    International Nuclear Information System (INIS)

    Giauque, R.D.; Garrett, R.B.; Goda, L.Y.; Jaklevic, J.M.; Malone, D.F.

    1975-01-01

    A semiconductor detector x-ray spectrometer has been constructed for the analysis of elements in air particulate specimens. The excitation radiation is provided, either directly or indirectly, using a low power (40 watts) Ag anode x-ray tube. Less than 100 ng for most of the elements in the range Mg → Zr, Pb are easily detected within two 1-minute counting intervals. A calibration technique for light element analysis and an experimental method which compensates for particle size effects are discussed. (auth)

  8. 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)

  9. Low Energy X-Ray and Electron Physics and Technology for High-Temperature Plasma Diagnostics

    Science.gov (United States)

    1987-10-01

    cransmission band for Che rejeccion of such background radiacions around Che 500-1000 eV region by combining as a primary monochromator a 300 ßg...X-Radiations of the Solar Corona," Technical Report No. 7, 1-413, AFOSR 66-2446 (September 1966). 30. "X-Ray Absorption in the 2 to

  10. X-ray induction by low energy protons: the quantification problem

    International Nuclear Information System (INIS)

    Oliver, A.; Miranda, J.

    1988-01-01

    The quantification analysis employing X-ray induction produced by protons with energies lower than 1 MeV, must be done considering the variations on cross sections by proton energy loss, when crossing the target. In this work, it is presented some results of thickness of thin films in the determination of alloys. (A.C.A.S.) [pt

  11. An InGrid based Low Energy X-ray Detector

    CERN Document Server

    Krieger, Christoph; Kaminski, Jochen; Lupberger, Michael; Vafeiadis, Theodoros

    2014-01-01

    An X-ray detector based on the combination of an integrated Micromegas stage with a pixel chip has been built in order to be installed at the CERN Axion Solar Telescope. Due to its high granularity and spatial resolution this detector allows for a topological background suppression along with a detection threshold below $1\\,\\text{keV}$. Tests at the CAST Detector Lab show the detector's ability to detect X-ray photons down to an energy as low as $277\\,\\text{eV}$. The first background data taken after the installation at the CAST experiment underline the detector's performance with an average background rate of $5\\times10^{-5}\\,/\\text{keV}/\\text{cm}^2/\\text{s}$ between 2 and $10\\,\\text{keV}$ when using a lead shielding.

  12. Low-energy x-ray response of photographic films. Part I. Mathematical models

    International Nuclear Information System (INIS)

    Henke, B.L.; Kwok, S.L.; Uejio, J.Y.; Yamada, H.T.; Young, G.C.

    1984-01-01

    Relatively simple mathematical models are developed for optical density as a function of the x-ray intensity, its angle of incidence and photon energy in the 100 to 10,000 eV region for monolayer and emulsion types of photographic films. Semi-empirical relations have been applied to characterize a monolayer film, Kodak 101-07, and an emulsion type film, Kodak RAR 2497, which fit calibration data at nine photon energies well within typical experimental error

  13. Low-energy x-ray response of photographic films. I. Mathematical models

    International Nuclear Information System (INIS)

    Henke, B.L.; Kwok, S.L.; Uejio, J.Y.; Yamada, H.T.; Young, G.C.

    1984-01-01

    Relatively simple mathematical models are developed to determine the optical density as a function of the x-ray intensity, its angle of incidence, and its photon energy in the 100--10,000-eV region for monolayer and emulsion types of photographic films. Semiempirical relations are applied to characterize a monolayer film (Kodak 101-07) and an emilsion-type film (Kodak RAR 2497); these relations fit calibration data at nine photon energies well within typical experimental error

  14. Induction of strand breaks in DNA films by low energy electrons and soft X-ray under nitrous oxide atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Alizadeh, Elahe, E-mail: Elahe.Alizadeh@USherbrooke.ca [Groupe en science des radiations, Departement de medecine nucleaire et radiobiologie, Faculte de medecine et des sciences de la sante, Universite de Sherbrooke, Sherbrooke, J1H 5N4 (Canada); Sanche, Leon, E-mail: Leon.Sanche@USherbrooke.ca [Groupe en science des radiations, Departement de medecine nucleaire et radiobiologie, Faculte de medecine et des sciences de la sante, Universite de Sherbrooke, Sherbrooke, J1H 5N4 (Canada)

    2012-01-15

    Five-monolayer (5 ML) plasmid DNA films deposited on glass and tantalum substrates were exposed to Al K{sub {alpha}} X-rays of 1.5 keV under gaseous nitrous oxide (N{sub 2}O) at atmospheric pressure and temperature. Whereas the damage yields for DNA deposited on glass are due to soft X-rays, those arising from DNA on tantalum are due to both the interaction of low energy photoelectrons from the metal and X-rays. Then, the differences in the yields of damage on glass and tantalum substrates, essentially arises from interaction of essentially low-energy electrons (LEEs) with DNA molecules and the surrounding atmosphere. The G-values (i.e., the number of moles of product per Joule of energy absorbed) for DNA strand breaks induced by LEEs (G{sub LEE}) and the lower limit of G-values for soft X-ray photons (G{sub XL}) were calculated and the results compared to those from previous studies under atmospheric conditions and other ambient gases, such as N{sub 2} and O{sub 2}. Under N{sub 2}O, the G-values for loss of supercoiled DNA are 103{+-}15 nmol/J for X-rays, and 737{+-}110 nmol/J for LEEs. Compared to corresponding values in an O{sub 2} atmosphere, the effectiveness of X-rays to damage DNA in N{sub 2}O is less, but the G value for LEEs in N{sub 2}O is more than twice the corresponding value for an oxygenated environment. This result indicates a higher effectiveness for LEEs relative to N{sub 2} and O{sub 2} environments in causing SSB and DSB in an N{sub 2}O environment. Thus, the previously observed radiosensitization of cells by N{sub 2}O may not be only due to OH{sup {center_dot}} radicals but also to the reaction of LEE with N{sub 2}O molecules near DNA. The previous experiments with N{sub 2} and O{sub 2} and the present one demonstrate the possibility to investigate damage induced by LEEs to biomolecules under various types of surrounding atmospheres. - Highlights: > A completely different and new approach is applied to investigate the radiation chemistry of N

  15. Analysis of the procedures and criteria for implantation of X-ray beams for ISO 4037 reference at low energies

    International Nuclear Information System (INIS)

    Figueiredo, Marcus Tadeu Tanuri de

    2012-01-01

    According to the radiological protection principles, practices involving ionizing radiation must be planned and carried out under the guarantee that the values of individual doses, the number of people exposed to radiation and the probability of accidental exposures are as low as reasonably achievable. Therefore, radiation dosimetry is required to be done with reliable instruments designed for measuring dosimetric quantities. The reliability of the dosimetry depends on both the calibration of the dosimeter and its proper performance under certain test conditions. The International Standardization Organization (ISO), in order to promote international standardization and metrological coherency, established sets of reference X-ray beams for dosimeter calibration and typing-test; they are expected to be implemented in metrology laboratories in compliance with specific technical requirements. At low energies there are specific requirements that need to be considered in both the implementation of the reference beams and their use in calibration and testing. The present study is an analysis of the procedures and criteria for ISO 4037 reference radiation implementation, at low energies. In the Dosimeter Calibration Laboratory of the Development Center of Nuclear Technology (LCD / CDTN), experiments were performed for determining the X-ray reference radiation parameters. Alternatives to the usual methods for half-value layer determination were studied. Spectra of reference beams were simulated with software and compared with experimental measurements. Different climatic conditions were reproduced in the Laboratory for analysis of its influence on the determination of the beam parameters. Uncertainties in the measurements of studied parameters were evaluated. According to the ISO 4037 criteria, the low energy X-ray beams were considered to be implemented; they allowed the determination of the conversion coefficients from air kerma to the operational radiation protection

  16. Food irradiation by low energy electrons

    International Nuclear Information System (INIS)

    Bird, J.R.

    1985-01-01

    For some special cases, the use of low energy electrons has advantages over the use of gamma-rays or higher energy electrons for the direct irradiation of food. These advantages arise from details of the interaction processes which are responsible for the production of physical, chemical and biological effects. Factors involved include depth of penetration, dose distribution, irradiation geometry, the possible production of radioactivity and costs

  17. Low-energy X-ray detection in cryogenic detectors with tungsten thermometers

    International Nuclear Information System (INIS)

    Colling, P.; Nucciotti, A.; Bucci, C.; Cooper, S.; Ferger, P.; Frank, M.; Nagel, U.; Proebst, F.; Seidel, W.

    1994-08-01

    In the course of our development of calorimetric particle detectors with superconducting phase transition thermometers, we have succeeded in depositing epitaxial α-tungsten films on sapphire which have critical temperatures T c near 15 mK. To our knowledge this is the first time that the T c of bulk tungsten has been observed in thin films. Such films used as thermometers are very sensitive and provide good energy resolution: with 4 g and 32 g sapphire crystals energy resolutions of better than 100eV (FWHM) for 1.5 KeV X-rays have been achieved. (orig.)

  18. Extension to Low Energies (<7keV) of High Pressure X-Ray Absorption Spectroscopy

    International Nuclear Information System (INIS)

    Itie, J.-P.; Flank, A.-M.; Lagarde, P.; Idir, M.; Polian, A.; Couzinet, B.

    2007-01-01

    High pressure x-ray absorption has been performed down to 3.6 keV, thanks to the new LUCIA beamline (SLS, PSI) and to the use of perforated diamonds or Be gasket. Various experimental geometries are proposed, depending on the energy of the edge and on the concentration of the studied element. A few examples will be presented: BaTiO3 at the titanium K edge, Zn0.95 Mn0.05O at the manganese K edge, KCl at the potassium K edge

  19. Si(Li) detectors with thin dead layers for low energy x-ray detection

    International Nuclear Information System (INIS)

    Rossington, C.S.; Walton, J.T.; Jaklevic, J.M.

    1990-10-01

    Regions of incomplete charge collection, or ''dead layers'', are compared for Si(Li) detectors fabricated with Au and Pd entrance window electrodes. The dead layers were measured by characterizing the detector spectral response to x-ray energies above and below the Si Kα absorption edge. It was found that Si(Li) detectors with Pd electrodes exhibit consistently thinner effective Si dead layers than those with Au electrodes. Furthermore, it is demonstrated that the minimum thickness required for low resistivity Pd electrodes is thinner than that required for low resistivity Au electrodes, which further reduces the signal attenuation in Pd/Si(Li) detectors. A model, based on Pd compensation of oxygen vacancies in the SiO 2 at the entrance window Si(Li) surface, is proposed to explain the observed differences in detector dead layer thickness. Electrode structures for optimum Si(Li) detector performance at low x-ray energies are discussed. 18 refs., 8 figs., 1 tab

  20. Inspection of small multi-layered plastic tubing during extrusion, using low-energy X-ray beams

    International Nuclear Information System (INIS)

    Armentrout, C.; Basinger, T.; Beyer, J.; Colesa, B.; Olsztyn, P.; Smith, K.; Strandberg, C.; Sullivan, D.; Thomson, J.

    1999-01-01

    The automotive industry uses nylon tubing with a thin ETFE (ethylene-tetrafluroethylene) inner layer to carry fuel from the tank to the engine. This fluorocarbon inner barrier layer is important to reduce the migration of hydrocarbons into the environment. Pilot Industries has developed a series of real-time inspection stations for dimensional measurements and flaw detection during the extrusion of this tubing. These stations are named LERA TM (low-energy radioscopic analysis), use a low energy X-ray source, a special high-resolution image converter and intensifier (ICI) stage, image capture hardware, a personal computer, and software that was specially designed to meet this task. Each LERA TM station operates up to 20 h a day, 6 days a week and nearly every week of the year. The tubing walls are 1-2 mm thick and the outer layer is nylon and the inner 0.2 mm thick layer is ethylene-tetrafluroethylene

  1. 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

  2. The influence of an extrapolation chamber over the low energy X-ray beam radiation field

    Energy Technology Data Exchange (ETDEWEB)

    Tanuri de F, M. T.; Da Silva, T. A., E-mail: mttf@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear / CNEN, Av. Pte. Antonio Carlos 6627, 31270-901 Pampulha, Belo Horizonte, Minas Gerais (Brazil)

    2016-10-15

    The extrapolation chambers are detectors whose sensitive volume can be modified by changing the distance between the electrodes and has been widely used for beta particles primary measurement system. In this work, was performed a PTW 23392 extrapolation chamber Monte Carlo simulation, by mean the MCNPX code. Although the sensitive volume of an extrapolation chamber can be reduced to very small size, their packaging is large enough to modify the radiation field and change the absorbed dose measurements values. Experiments were performed to calculate correction factors for this purpose. The validation of the Monte Carlo model was done by comparing the spectra obtained with a CdTe detector according to the ISO 4037 criteria. Agreements smaller than 5% for half value layers, 10% for spectral resolution and 1% for mean energy, were found. It was verified that the correction factors are dependent of the X-ray beam quality. (Author)

  3. The influence of an extrapolation chamber over the low energy X-ray beam radiation field

    International Nuclear Information System (INIS)

    Tanuri de F, M. T.; Da Silva, T. A.

    2016-10-01

    The extrapolation chambers are detectors whose sensitive volume can be modified by changing the distance between the electrodes and has been widely used for beta particles primary measurement system. In this work, was performed a PTW 23392 extrapolation chamber Monte Carlo simulation, by mean the MCNPX code. Although the sensitive volume of an extrapolation chamber can be reduced to very small size, their packaging is large enough to modify the radiation field and change the absorbed dose measurements values. Experiments were performed to calculate correction factors for this purpose. The validation of the Monte Carlo model was done by comparing the spectra obtained with a CdTe detector according to the ISO 4037 criteria. Agreements smaller than 5% for half value layers, 10% for spectral resolution and 1% for mean energy, were found. It was verified that the correction factors are dependent of the X-ray beam quality. (Author)

  4. Characterization of an extrapolation chamber for low-energy X-rays: Experimental and Monte Carlo preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Neves, Lucio P., E-mail: lpneves@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN), Comissao Nacional de Energia Nuclear, Av. Prof. Lineu Prestes 2242, 05508-000 Sao Paulo, SP (Brazil); Silva, Eric A.B., E-mail: ebrito@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN), Comissao Nacional de Energia Nuclear, Av. Prof. Lineu Prestes 2242, 05508-000 Sao Paulo, SP (Brazil); Perini, Ana P., E-mail: aperini@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN), Comissao Nacional de Energia Nuclear, Av. Prof. Lineu Prestes 2242, 05508-000 Sao Paulo, SP (Brazil); Maidana, Nora L., E-mail: nmaidana@if.usp.br [Universidade de Sao Paulo, Instituto de Fisica, Travessa R 187, 05508-900 Sao Paulo, SP (Brazil); Caldas, Linda V.E., E-mail: lcaldas@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN), Comissao Nacional de Energia Nuclear, Av. Prof. Lineu Prestes 2242, 05508-000 Sao Paulo, SP (Brazil)

    2012-07-15

    The extrapolation chamber is a parallel-plate ionization chamber that allows variation of its air-cavity volume. In this work, an experimental study and MCNP-4C Monte Carlo code simulations of an ionization chamber designed and constructed at the Calibration Laboratory at IPEN to be used as a secondary dosimetry standard for low-energy X-rays are reported. The results obtained were within the international recommendations, and the simulations showed that the components of the extrapolation chamber may influence its response up to 11.0%. - Highlights: Black-Right-Pointing-Pointer A homemade extrapolation chamber was studied experimentally and with Monte Carlo. Black-Right-Pointing-Pointer It was characterized as a secondary dosimetry standard, for low energy X-rays. Black-Right-Pointing-Pointer Several characterization tests were performed and the results were satisfactory. Black-Right-Pointing-Pointer Simulation showed that its components may influence the response up to 11.0%. Black-Right-Pointing-Pointer This chamber may be used as a secondary standard at our laboratory.

  5. Irradiating cell samples in an x-ray radiation cabinet-the effect of tube filtration

    International Nuclear Information System (INIS)

    Parkin, Adrian; Wright, Ian; Yates, Stuart; Goldstone, Karen E; Russell, Paul; Starr, Christy

    2004-01-01

    The cell irradiation cabinet described is used for creating DNA damage in cell samples in order to study tumourigenesis. The medical research laboratory involved was using the manufacturer's quoted dose rate (32.2 mGy s -1 ) to determine the required exposure time to impart a dose of 10 Gy. The x-ray output was investigated when the exposure failed to produce cell cycle arrest. The x-ray tube was fitted with only a 0.76 mm beryllium filter, and the spectrum therefore contained a high proportion of low energy photons which were being removed by the polystyrene sample flask as demonstrated by dose measurements in air and through the sample flask. Incorporation of a 0.5 mm aluminium filter removed most of these low energy photons but greatly reduced the dose rate to 3.8 mGy s -1 . The manufacturer's quoted dose rates from a lightly filtered tube are misleading: the contribution of the very low energy component of the spectrum to the dose is not relevant since it will be removed by a sample flask. (note)

  6. 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

  7. 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

  8. 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

  9. Control of the Low-energy X-rays by Using MCNP5 and Numerical Analysis for a New Concept Intra-oral X-ray Imaging System

    Science.gov (United States)

    Huh, Jangyong; Ji, Yunseo; Lee, Rena

    2018-05-01

    An X-ray control algorithm to modulate the X-ray intensity distribution over the FOV (field of view) has been developed by using numerical analysis and MCNP5, a particle transport simulation code on the basis of the Monte Carlo method. X-rays, which are widely used in medical diagnostic imaging, should be controlled in order to maximize the performance of the X-ray imaging system. However, transporting X-rays, like a liquid or a gas is conveyed through a physical form such as pipes, is not possible. In the present study, an X-ray control algorithm and technique to uniformize the Xray intensity projected on the image sensor were developed using a flattening filter and a collimator in order to alleviate the anisotropy of the distribution of X-rays due to intrinsic features of the X-ray generator. The proposed method, which is combined with MCNP5 modeling and numerical analysis, aimed to optimize a flattening filter and a collimator for a uniform distribution of X-rays. Their size and shape were estimated from the method. The simulation and the experimental results both showed that the method yielded an intensity distribution over an X-ray field of 6×4 cm2 at SID (source to image-receptor distance) of 5 cm with a uniformity of more than 90% when the flattening filter and the collimator were mounted on the system. The proposed algorithm and technique are not only confined to flattening filter development but can also be applied for other X-ray related research and development efforts.

  10. Development of high resolution x-ray CT technique for irradiated fuel assembly

    Energy Technology Data Exchange (ETDEWEB)

    Ishimi, Akihiro; Katsuyama, Kozo; Maeda, Koji; Asaga, Takeo [Japan Atomic Energy Agency, Oarai Research and Development Center, Oarai, Ibaraki (Japan)

    2012-03-15

    High X-ray CT technique was developed to observe the irradiation performance of FBR fuel assembly and MOX fuel. In this technique, the high energy X-ray pulse (12MeV) was used synchronizing detection system with the X-ray pulse to reduce the effect of the gamma ray emissions from the irradiated fuel assembly. In this study, this technique was upgraded to obtain high resolution X-ray CT image. In this upgrading, the collimator which had slit width of 0.1 mm and X-ray detector of a highly sensitive silicon semiconductor detector (100 channels) was introduced in the X-ray CT system. As a result of these developments, high resolution X-ray CT images could be obtained on the transverse cross section of irradiated fuel assembly. (author)

  11. A new large solid angle multi-element silicon drift detector system for low energy X-ray fluorescence spectroscopy

    Science.gov (United States)

    Bufon, J.; Schillani, S.; Altissimo, M.; Bellutti, P.; Bertuccio, G.; Billè, F.; Borghes, R.; Borghi, G.; Cautero, G.; Cirrincione, D.; Fabiani, S.; Ficorella, F.; Gandola, M.; Gianoncelli, A.; Giuressi, D.; Kourousias, G.; Mele, F.; Menk, R. H.; Picciotto, A.; Rachevski, A.; Rashevskaya, I.; Sammartini, M.; Stolfa, A.; Zampa, G.; Zampa, N.; Zorzi, N.; Vacchi, A.

    2018-03-01

    Low-energy X-ray fluorescence (LEXRF) is an essential tool for bio-related research of organic samples, whose composition is dominated by light elements. Working at energies below 2 keV and being able to detect fluorescence photons of lightweight elements such as carbon (277 eV) is still a challenge, since it requires in-vacuum operations to avoid in-air photon absorption. Moreover, the detectors must have a thin entrance window and collect photons at an angle of incidence near 90 degrees to minimize the absorption by the protective coating. Considering the low fluorescence yield of light elements, it is important to cover a substantial part of the solid angle detecting ideally all emitted X-ray fluorescence (XRF) photons. Furthermore, the energy resolution of the detection system should be close to the Fano limit in order to discriminate elements whose XRF emission lines are often very close within the energy spectra. To ensure all these features, a system consisting of four monolithic multi-element silicon drift detectors was developed. The use of four separate detector units allows optimizing the incidence angle on all the sensor elements. The multi-element approach in turn provides a lower leakage current on each anode, which, in combination with ultra-low noise preamplifiers, is necessary to achieve an energy resolution close to the Fano limit. The potential of the new detection system and its applicability for typical LEXRF applications has been proved on the Elettra TwinMic beamline.

  12. Measurement of the exposure rate due to low energy x-rays emitted from video display terminals

    International Nuclear Information System (INIS)

    Campos, L.L.

    1988-01-01

    Thermoluminescent dosimeters of CaSO 4 :Dy have been used to measure the low energy x-rays emitted from Video Display Terminals (VDTs). For each terminal, three points were measured with five dosimeters at each point. The points were at distances of 5 and 50 cm in front of the screen and at 65 cm with an angle of approximately 50 0 . The last two positions approximate to positions of the lenses of the eye and the gonads respectively. A survey of 50 VDTs at a distance of 5 cm from the screen resulted in exposure rates nearly fifteen times below the exposure rate of 0.5 mR h -1 (0.129 μC kg -1 h -1 ) which is the limit recommended by the International Atomic Energy Agency (IAEA), Safety Series No. 9 (1967) Basic Safety Standards for Radiation Protection. (author)

  13. 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)

  14. 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)

  15. Is low-energy-ion bombardment generated X-ray emission a secondary mutational source to ion-beam-induced genetic mutation?

    Energy Technology Data Exchange (ETDEWEB)

    Thongkumkoon, P. [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); 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); Thopan, P.; Yaopromsiri, C. [Plasma and Beam Physics Research Facility, Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Suwannakachorn, D. [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); 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: ► Detected X-ray emission from metal, plastic and biological samples. ► Characteristic X-ray emission was detected from metal but not from non-metals. ► Low-energy ion bombarded bacteria held in different sample holders. ► Bacteria held in metal holder had higher mutation rate than in plastic holder. ► Ion-beam-induced X-ray from biological sample is not a basic mutation source. -- Abstract: Low-energy ion beam biotechnology has achieved tremendous successes in inducing crop mutation and gene transfer. However, mechanisms involved in the related processes are not yet well understood. In ion-beam-induced mutation, ion-bombardment-produced X-ray has been proposed to be one of the secondary mutation sources, but the speculation has not yet been experimentally tested. We carried out this investigation to test whether the low-energy ion-beam-produced X-ray was a source of ion-beam-induced mutation. In the investigation, X-ray emission from 29-keV nitrogen- or argon- ion beam bombarded bacterial Escherichia coli (E. coli) cells held in a metal or plastic sample holder was in situ detected using a highly sensitive X-ray detector. The ion beam bombarded bacterial cells held in different material holders were observed for mutation induction. The results led to a conclusion that secondary X-ray emitted from ion-beam-bombarded biological living materials themselves was not a, or at least a negligible, mutational source, but the ion-beam-induced X-ray emission from the metal that made the sample holder could be a source of mutation.

  16. Is low-energy-ion bombardment generated X-ray emission a secondary mutational source to ion-beam-induced genetic mutation?

    International Nuclear Information System (INIS)

    Thongkumkoon, P.; Prakrajang, K.; Thopan, P.; Yaopromsiri, C.; Suwannakachorn, D.; Yu, L.D.

    2013-01-01

    Highlights: ► Detected X-ray emission from metal, plastic and biological samples. ► Characteristic X-ray emission was detected from metal but not from non-metals. ► Low-energy ion bombarded bacteria held in different sample holders. ► Bacteria held in metal holder had higher mutation rate than in plastic holder. ► Ion-beam-induced X-ray from biological sample is not a basic mutation source. -- Abstract: Low-energy ion beam biotechnology has achieved tremendous successes in inducing crop mutation and gene transfer. However, mechanisms involved in the related processes are not yet well understood. In ion-beam-induced mutation, ion-bombardment-produced X-ray has been proposed to be one of the secondary mutation sources, but the speculation has not yet been experimentally tested. We carried out this investigation to test whether the low-energy ion-beam-produced X-ray was a source of ion-beam-induced mutation. In the investigation, X-ray emission from 29-keV nitrogen- or argon- ion beam bombarded bacterial Escherichia coli (E. coli) cells held in a metal or plastic sample holder was in situ detected using a highly sensitive X-ray detector. The ion beam bombarded bacterial cells held in different material holders were observed for mutation induction. The results led to a conclusion that secondary X-ray emitted from ion-beam-bombarded biological living materials themselves was not a, or at least a negligible, mutational source, but the ion-beam-induced X-ray emission from the metal that made the sample holder could be a source of mutation

  17. 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)

  18. Elemental distribution in ascending aortic after radiotherapy and chemotherapy by Low Energy X-ray Fluorescence spectroscopy

    Science.gov (United States)

    Mantuano, A.; Mota, C. L.; Pickler, A.; Sena, G.; Braz, D.; Salata, C.; de Almeida, C. E.; Costa, F. N.; Barroso, R. C.

    2018-05-01

    Breast cancer (BC) is the most frequent cancer and the leading cause of cancer-related mortality in women. The treatment techniques for the BC include chemotherapy (CT) and/or radiotherapy (RT) and can modify elementary the cell matrix by calcificating tissues due to biological and morphological changes. Also, treatments for BC induce cardiotoxicity and it is important to understand the mechanisms involved in order to prevent this late effect in treated breast cancer patients. The high incidence of cardiovascular mortality in breast cancer patients is partially credited to increased intimal and medial calcifications of the aorta. The aim of this work is to investigate the distibution of low atomic number elements such as Magnesium (Mg), due to its importance for the cardiac metabolism; iron (Fe), since BC treatment may be associated with oxidative stress; and Sodium (Na), that is extremely related to the damage of endothelial cells. An optimal technique to observe these changes in aorta tissue is soft X-ray FLuorescence that can provide elemental maps of these important elements. The results performed by Low Energy X-ray Fluorescence LEXRF analyses showed that when the tissue is submitted to treatments with CT and/or RT, some normal structures become disorganized, and consequently the intensity of elemental compounds can be changed. All the experiments were carried out at the TwinMic beamline at Elettra Synchrotron facility using as animal model Wistar rats in order to evaluate the distribution of Na, Mg and Fe in aorta walls of Wistar rats, after BC treatment. Simultaneous acquisition of LEXRF and attenuation coefficient maps suggest that the combined chemotherapy and radiotherapy caused more damage to the aortic tissue as compared to radiation therapy alone. These findings add an in-depth understanding of elemental lack or excess in the tissue and contribute to locate these changes.

  19. Adjustment of a low energy, X-rays generator (6 kV - 50 mA). Application to X-rays detectors calibration

    International Nuclear Information System (INIS)

    Legistre, C.

    1995-02-01

    The aim of this memoir is the calibration of an aluminium photocathode X-rays photoelectric detector, in the spectral range 0,5 keV - 1,5 KeV, with a continuous X-ray source. The detectors's calibration consist to measure the detector's sensitivity versus incident energy. In order to produce monochromatic incident beam on the detector, we used a multilayer mirror whose reflectivity was characterized. The measurements are compared to those realized in an other laboratory. (authors). 36 refs., 61 figs., 13 tabs., 2 photos

  20. Simulation of medical irradiation and X-ray detector signals

    Energy Technology Data Exchange (ETDEWEB)

    Kreisler, Bjoern

    2010-02-08

    -Carlo simulation of the irradiation head of the medical linear accelerator is constructed for the irradiation with electrons and photons in the second part of this thesis. The simulation is validated by comparison with water phantom measurements. Available information from the measurements is limited to the depth dose deposition and dose profiles in selected water depths. The simulation allows the evaluation of dose depositions and spectral particle distributions at various locations. In the electron irradiation mode, a collimation close to the patient is performed by an electron applicator. A possible reduction of the side leakage is evaluated by optimising the collimation of the beam. Medical irradiation with MeV-electrons and X-ray photons is the part of the clinical tumour treatment which is evaluated in this work. (orig.)

  1. Simulation of medical irradiation and X-ray detector signals

    International Nuclear Information System (INIS)

    Kreisler, Bjoern

    2010-01-01

    the irradiation head of the medical linear accelerator is constructed for the irradiation with electrons and photons in the second part of this thesis. The simulation is validated by comparison with water phantom measurements. Available information from the measurements is limited to the depth dose deposition and dose profiles in selected water depths. The simulation allows the evaluation of dose depositions and spectral particle distributions at various locations. In the electron irradiation mode, a collimation close to the patient is performed by an electron applicator. A possible reduction of the side leakage is evaluated by optimising the collimation of the beam. Medical irradiation with MeV-electrons and X-ray photons is the part of the clinical tumour treatment which is evaluated in this work. (orig.)

  2. In situ x-ray diffraction investigations during low energy ion nitriding of austenitic stainless steel grade 1.4571

    International Nuclear Information System (INIS)

    Manova, D; Mändl, S; Gerlach, J W; Hirsch, D; Neumann, H; Rauschenbach, B

    2014-01-01

    Insertion of nitrogen into austenitic stainless steel leads to anomalously fast nitrogen diffusion and the formation of an expanded face-centred cubic phase which is known to contain a large amount of mechanical stress. In situ x-ray diffraction (XRD) measurements during low energy nitrogen ion implantation into steel 316Ti at 300–550 °C allow a direct view into diffusion and phase formation. While the layer growth is directly observable from the decreasing substrate reflection intensity, the time evolution of the intensities for the expanded phase reflection is much more complex: several mechanisms including at least formation and annealing of defects, twinning, reduction of the crystal symmetry, or grain rotation may be active inside the expanded phase, besides the thermally activated decay of the metastable expanded phase. This locally varying coherence length or scattering intensity from the expanded phase is furthermore a function of temperature and time, additionally complicating the deconvolution of XRD spectra for stress and concentration gradients. As no concise modelling of this coherence length is possible at present, a simple qualitative model assuming a dependence of the scattering intensity on the depth, influence by stress and plastic flow during the nitriding process is proposed for understanding the underlying processes. (paper)

  3. Establishment of a primary standard system for low energy X-rays using a free air ionization chamber

    International Nuclear Information System (INIS)

    Silva, Natalia Fiorini da

    2016-01-01

    In this work a primary standard system was established for low energy X-rays (10 kV to 50 kV), using a free air ionization chamber with concentric cylinders, Victoreen (Model 481-5), at the Calibration Laboratory of Instruments (LCI) of the Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP). For this, a new ionization chamber alignment protocol was developed for the radiation system and a modification on the micrometer housing used for the movement of the internal cylinders was ma de. The results obtained for the stability and characterization tests showed to be within the limits established by the standards IEC 61674 and IEC 60731. The correction factors for photon attenuation in the air, transmission and scattering in the diaphragm, scattering and fluorescence and ion recombination were also determined. These values were compared with those obtained by the German primary standard laboratory, Physikalisch-Technische Bundesanstalt (PTB), showing good agreement. Finally, the absolute values of the quantity air kerma rate for the standard qualities direct beams MWV28 and WMV35 and the attenuated beams WMH28 and WMH35 were determined; the results are in agreement, with a maximum difference of 3,8% with the values obtained using the secondary standard system of LCI. (author)

  4. Highly sensitive x-ray detectors in the low-energy range on n-type 4H-SiC epitaxial layers

    Energy Technology Data Exchange (ETDEWEB)

    Mandal, Krishna C.; Muzykov, Peter G. [Department of Electrical Engineering, University of South Carolina, Columbia, South Carolina 29208 (United States); Russell Terry, J. [Space Science and Applications Group (ISR-1), Intelligence and Space Research Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2012-07-30

    Schottky diodes on n-type 4H-SiC epitaxial layers have been fabricated for low-energy x-ray detection. The detectors were highly sensitive to soft x-rays and showed improved response compared to the commercial SiC UV photodiodes. Current-voltage characteristics at 475 K showed low leakage current revealing the possibility of high temperature operation. The high quality of the epi-layer was confirmed by x-ray diffraction and chemical etching. Thermally stimulated current measurements performed at 94-550 K revealed low density of deep levels which may cause charge trapping. No charge trapping on detectors' responsivity in the low x-ray energy was found.

  5. 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)

  6. 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)

  7. Comparison of the air-kerma standards of the BEV and the BIPM in the low-energy X-ray range

    International Nuclear Information System (INIS)

    Burns, D.T.; Witzani, J.

    2002-09-01

    A direct comparison has been made between the air-kerma standards of the BEV and the BIPM in the low-energy x-ray range. The results at the different radiation qualities show the standards to be in reasonable agreement with respect to the combined relative standard uncertainty of the comparison of 2.4 x 10 -3 . (authors)

  8. 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.

  9. 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

  10. A portable organic plastic scintillator dosimetry system for low energy X-rays: a feasibility study using an intraoperative X-ray unit as the radiation source

    International Nuclear Information System (INIS)

    Williams, Kerry; Robinson, Neil; Trapp, Jamie; Geso, Moshi; Ackerly, Trevor; Das, Ram; Kemp, Penny

    2007-01-01

    The effective use of near water equivalent organic plastic scintillators (OPS) for radiation dosimetry with high-energy sources under laboratory conditions is recognized. In this work, an OPS-based dosimeter using a photodiode combined with improved solid state detection and signal processing techniques has been developed; it offers the potential for the construction of a stable and fully portable dosimeter which will extend the useful range of measurement beyond the usual MeV area and provide reliable readings down to sub-100 keV X-ray energy levels. In these experiments, the instrument described has been used for the dosimetry of INTRABEAM intraoperative radiotherapy (IORT) equipment at distances as low as 1.8 mm from the effective source, i.e., 0.2 mm from the X-ray probe surface. Comparison is shown with dosimetry measurements made using the calibrated reference ion chamber supplied by the IORT equipment manufacturer. (author)

  11. Detectability of Sungrazing Comet Soft X-ray Irradiance

    Directory of Open Access Journals (Sweden)

    Su Yeon Oh

    2007-12-01

    Full Text Available Originating from the Oort cloud, some comets disappear to impact against the Sun or to split up by strong gravitational force. Then they don't go back to the Oort cloud. They are called sungrazing comets. The comets are detected by sublimation of ices and ejection of gas and dust through solar heat close to the Sun. There exists the charge transfer from heavy ions in the solar wind to neutral atoms in the cometary atmosphere by interaction with the solar wind. Cometary atoms would be excited to high electronic levels and their de-excitation would result in X-ray emission, or it would be scattering of solar X-ray emission by very small cometary grains. We calculated the X-ray emission applying the model suggested by Mendis & Flammer (1984 and Cravens (1997. In our estimation, the sungrazing comet whose nucleus size is about 1 km in radius might be detectable within a distance of 3 solar radius from the sun on soft X-ray solar camera.

  12. 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

  13. 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.

  14. 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

  15. Development of a methodology for low-energy X-ray absorption correction in biological samples using radiation scattering techniques

    International Nuclear Information System (INIS)

    Pereira, Marcelo O.; Anjos, Marcelino J.; Lopes, Ricardo T.

    2009-01-01

    Non-destructive techniques with X-ray, such as tomography, radiography and X-ray fluorescence are sensitive to the attenuation coefficient and have a large field of applications in medical as well as industrial area. In the case of X-ray fluorescence analysis the knowledge of photon X-ray attenuation coefficients provides important information to obtain the elemental concentration. On the other hand, the mass attenuation coefficient values are determined by transmission methods. So, the use of X-ray scattering can be considered as an alternative to transmission methods. This work proposes a new method for obtain the X-ray absorption curve through superposition peak Rayleigh and Compton scattering of the lines L a e L β of Tungsten (Tungsten L lines of an X-ray tube with W anode). The absorption curve was obtained using standard samples with effective atomic number in the range from 6 to 16. The method were applied in certified samples of bovine liver (NIST 1577B) , milk powder and V-10. The experimental measurements were obtained using the portable system EDXRF of the Nuclear Instrumentation Laboratory (LIN-COPPE/UFRJ) with Tungsten (W) anode. (author)

  16. Clinical aspects of intraoperative radiotherapy in early breast cancer: short-term complications after IORT in women treated with low energy x-rays

    International Nuclear Information System (INIS)

    Tuschy, Benjamin; Berlit, Sebastian; Romero, Simone; Sperk, Elena; Wenz, Frederik; Kehl, Sven; Sütterlin, Marc

    2013-01-01

    To assess postoperative complications, clinical outcome and histological findings in patients undergoing intraoperative radiotherapy with low energy x-rays for early breast cancer. We retrospectively analysed data of 208 women who underwent intraoperative irradiation during breast conserving surgery (BCS) between 2002 and 2007. Demographic, clinical and surgical parameters as well as short-term complications within the first postoperative week and histological findings were evaluated. Toxicities were assessed using the CTC/EORTC Score. Postoperative complications were rare and the immediate toxicity low, without any grade 3/4 acute toxicity. The most frequent postoperative side effects were suggillation (24%) and palpable seroma (17.3%). In 78.6% of the axillary seroma and in 25% of the breast seroma a needle aspiration was inevitable. Erythema grade I-II of the breast was found in 27 women (13%); whereas in 7 patients (3.4%), mastitis was confirmed. In 57.7% of the cases, the pathological assessment revealed ductal invasive breast cancer and tumour size ranged between 0.1 and 4.5 cm (mean = 1.6 cm). IORT using Intrabeam ® during BCS is safe, although it is associated with postoperative adverse events such as seroma. These should be mentioned and explained to women in detail during the preoperative discussion. This explicitly clinical description is useful for daily clinical practice; especially for giving a detailed analysis of the postoperative side effects during preoperative counselling

  17. 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...

  18. 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 ...

  19. 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

  20. 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.

  1. Studies on combination effects of peplomycin and x-ray irradiation

    International Nuclear Information System (INIS)

    Munenaga, Yasuichi

    1984-01-01

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

  2. 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.

  3. Comparison of the air-kerma standards of the VNIIM and the BIPM in the low-energy X-ray range

    International Nuclear Information System (INIS)

    Burns, D.T.; Villevalde, N.D.; Oborin, A.V.; Yurjatin, E.N.

    2002-05-01

    An indirect comparison has been made between the air erma standards of the VNIIM and the BIPM in the low-energy x-ray range. The results show the standards to be in agreement at the level of one to two standard uncertainties. The trend in the results at different radiation qualities is explained in terms of the photon-scatter correction applied to the VNIIM standard. (authors)

  4. 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.

  5. Possibility of coherent hard x-ray production by pumping with synchrotron radiation and low energy photons. Period covered: November 17, 1976--August 16, 1977

    International Nuclear Information System (INIS)

    Csonka, P.L.

    1977-01-01

    Coherent x-rays in the keV range could be produced by pumping a suitable gas with synchrotron radiation in combination with low energy photon beams in the presence of appropriately arranged mirrors. With a wiggler magnet placed in the low beta section of the PEP machine to be constructed at Stanford, 1020 eV coherent photons could be produced from Ne. Appropriate synchrotron radiation will produce a highly ionized cool gas. Low energy photons modify the outer electron structure of ions to enhance lasing: they modify the lifetime of the inverted state, counterbalance unwanted collisionally induced transitions, reduce Stark line broadening

  6. 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.

  7. Calculated and measured dose distribution in electron and X-ray irradiated water phantom

    CERN Document Server

    Ziaie, F; Bulka, S; Afarideh, H; Hadji-Saeid, S M

    2002-01-01

    The Bremsstrahlung yields produced by incident electrons on a tantalum converter have been calculated by using a Monte-Carlo computer code. The tantalum thickness as an X-ray converter was optimized for 2, 2.5, 5, 7.5, and 10 MeV electron beams. The dose distribution in scanning and conveyor direction for both 2 MeV electron and X-ray converted from 2 MeV electron beam have been calculated and compared with experimental results. The economical aspects of low energy electron conversion were discussed as well.

  8. Technical Note: Effect of explicit M and N-shell atomic transitions on a low-energy x-ray source

    Energy Technology Data Exchange (ETDEWEB)

    Watson, Peter G. F., E-mail: peter.watson@mail.mcgill.ca; Seuntjens, Jan [Medical Physics Unit, McGill University, Montreal, Quebec H4A 3J1 (Canada)

    2016-04-15

    Purpose: In EGSnrc, atomic transitions to and from the M and N-shells are treated in an average way by default. This approach is justified in which the energy difference between explicit and average M and N-shell binding energies is less than 1 keV, and for most applications can be considered negligible. However, for simulations of low energy x-ray sources on thin, high-Z targets, characteristic x-rays can make up a significant portion of the source spectra. As of release V4-2.4.0, EGSnrc has included an option to enable a more complete algorithm of all atomic transitions available in the EADL compilation. In this paper, the effect of M and N-shell averaging on the calculation of half-value layer (HVL) and relative depth dose (RDD) curve of a 50 kVp intraoperative x-ray tube with a thin gold target was investigated. Methods: A 50 kVp miniature x-ray source with a gold target (The INTRABEAM System, Carl Zeiss, Germany) was modeled with the EGSnrc user code cavity, both with and without M and N-shell averaging. From photon fluence spectra simulations, the source HVLs were determined analytically. The same source model was then used with egs-chamber to calculate RDD curves in water. Results: A 4% increase of HVL was reported when accounting for explicit M and N-shell transitions, and up to a 9% decrease in local relative dose for normalization at 3 mm depth in water. Conclusions: The EGSnrc default of using averaged M and N-shell binding energies has an observable effect on the HVL and RDD of a low energy x-ray source with high-Z target. For accurate modeling of this class of devices, explicit atomic transitions should be included.

  9. 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.

  10. 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)

  11. 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

  12. Measurement of actinide concentration in solution samples from the NUCEF reprocessing facility by X-ray and low energy gamma-ray spectroscopy

    International Nuclear Information System (INIS)

    Howarth, P.J.A.; Uchiyama, Gunzo; Asakura, Toshihide; Sawada, Mutsumi; Hagiya, Hiromichi; Fujine, Sachio

    1999-01-01

    X-ray and low-energy gamma-ray spectroscopy has been used to measure actinide concentration within the backend nuclear fuel reprocessing research facility at NUCEF. Research on advanced reprocessing techniques at NUCEF is based on the PARC refinement of the PUREX process which aims to recover Am and Cm from the highly active waste stream and to control and partition Np and Tc. It is hoped that the PARC process will mitigate the environmental impact of the wastes and improve the economy of reprocessing. The main actinides for which assay is required are U, Pu, Np and Am and knowledge of these concentrations will enable the following to be determined: i.) evaluation of the distribution of actinides throughout the reprocessing facility ii.) verification of the simulated actinide distribution from chemical kinetic simulations of the PARC process and iii.) assurance of safety and control over migrant radioactive species. The research presented here shows that passive measurement of x-rays and low-energy gamma-rays from solution samples provides an accurate and non-destructive means for assaying the concentration. The measurement technique is based on the use of the characteristic low energy gamma-rays and internal conversion x-ray emission from actinides (11 keV to 22 keV). The x-ray emission is a few orders of magnitude more intense than the characteristic gamma-ray emission and can be easily detected from solutions. The experimental system described here can be used for solution monitoring to a minimum concentration of typically 10-6 M for Pu, 10-10 M for Am and 10-6 M for Np. (author)

  13. 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.

  14. 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.

  15. 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.

  16. 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)

  17. 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)

  18. 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)

  19. Optimization of aluminum thickness for absorption of undesired Ti K X-rays in the measurement of low energy brachytherapy source strength

    Energy Technology Data Exchange (ETDEWEB)

    Kashian, S., E-mail: skashian@aeoi.org.ir [Radiation Applications Research School, Nuclear Science and Technology Research Institute, Tehran (Iran, Islamic Republic of); Physics Department, Shiraz University, Shiraz 71454 (Iran, Islamic Republic of); Raisali, G., E-mail: graisali@aeoi.org.ir [Radiation Applications Research School, Nuclear Science and Technology Research Institute, Tehran (Iran, Islamic Republic of); Eskandari, M.R., E-mail: eskandari@susc.ac.ir [Physics Department, Shiraz University, Shiraz 71454 (Iran, Islamic Republic of); Nuclear Engineering Department, Shiraz University, Shiraz (Iran, Islamic Republic of); Khalafi, H., E-mail: hkhalafi@aeoi.org.ir [Radiation Applications Research School, Nuclear Science and Technology Research Institute, Tehran (Iran, Islamic Republic of)

    2011-02-15

    The contribution of Ti K X-rays to total air kerma strength for low energy brachytherapy sources ({sup 125}I and {sup 103}Pd) are calculated for different source-to-aperture distances of an indigenously designed free air ionization chamber. For 30 cm source-to-aperture distance, calculated contribution of Ti K X-rays is 4%. The Ti K X-rays can be eliminated by a relatively thin aluminum filter, but the primary photons emitted by the source will also be attenuated. This effect should be compensated by applying a suitable correction factor. The uncertainty in the attenuation correction factor has been also calculated for different thicknesses of aluminum by a Monte Carlo uncertainty analysis algorithm programmed in FORTRAN. The results show that the optimum thickness of the aluminum absorber is 100 {mu}m, for which the contribution of Ti K X-rays in air kerma strength is reduced to less than one hundredth of the uncertainty in the correction factor, ensuring that the uncertainty in the air kerma strength will be mainly due to the uncertainty in the correction factor. The calculated uncertainties are 1.7 x 10{sup -3}, and 3.4 x 10{sup -3} for {sup 125}I and {sup 103}Pd sources, respectively.

  20. 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

  1. 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.

  2. 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

  3. 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

  4. 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

  5. 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.

  6. Low-energy x-ray and electron physics and applications to diagnostics development for laser-produced plasma research. Final report, April 30, 1980-April 29, 1981

    Energy Technology Data Exchange (ETDEWEB)

    Henke, B.L.

    1981-08-01

    This final report describes a collaborative extension of an ongoing research program in low-energy x-ray and electron physics into particular areas of immediate need for the diagnostics of plasmas as involved in laser-produced fusion research. It has been for the continued support for one year of a post-doctoral research associate and for three student research assistants who have been applied to the following specific efforts: (1) the continuation of our research on the absolute characterization of x-ray photocathode systems for the 0.1 to 10 keV photon energy region. The research results were applied collaboratively to the design, construction and calibration of photocathodes for time-resolved detection with the XRD and the streak and framing cameras; (2) the design, construction and absolute calibration of optimized, bolt-on spectrographs for the absolute measurement of laser-produced plasma spectra.

  7. Low-energy x-ray and electron physics and applications to diagnostics development for laser-produced plasma research. Final report, April 30, 1980-April 29, 1981

    International Nuclear Information System (INIS)

    Henke, B.L.

    1981-08-01

    This final report describes a collaborative extension of an ongoing research program in low-energy x-ray and electron physics into particular areas of immediate need for the diagnostics of plasmas as involved in laser-produced fusion research. It has been for the continued support for one year of a post-doctoral research associate and for three student research assistants who have been applied to the following specific efforts: (1) the continuation of our research on the absolute characterization of x-ray photocathode systems for the 0.1 to 10 keV photon energy region. The research results were applied collaboratively to the design, construction and calibration of photocathodes for time-resolved detection with the XRD and the streak and framing cameras; (2) the design, construction and absolute calibration of optimized, bolt-on spectrographs for the absolute measurement of laser-produced plasma spectra

  8. 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

  9. 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.)

  10. Low-energy X-ray and gamma spectrometry using silicon photodiodes; Espectrometria de raios X e gama de baixa energia utilizando fotodiodos de silicio

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Iran Jose Oliveira da

    2000-08-01

    The use of semiconductor detectors for radiation detection has increased in recent years due to advantages they present in comparison to other types of detectors. As the working principle of commercially available photodiodes is similar to the semiconductor detector, this study was carried out to evaluate the use of Si photodiodes for low energy x-ray and gamma spectrometry. The photodiodes investigated were SFH-205, SFH-206, BPW-34 and XRA-50 which have the following characteristics: active area of 0,07 cm{sup 2} and 0,25 cm{sup 2}, thickness of the depletion ranging from 100 to 200 {mu}m and junction capacitance of 72 pF. The photodiode was polarized with a reverse bias and connected to a charge sensitive pre-amplifier, followed by a amplifier and multichannel pulse analyzer. Standard radiation source used in this experiment were {sup 241} Am, {sup 109} Cd, {sup 57} Co and {sup 133} Ba. The X-ray fluorescence of lead and silver were also measured through K- and L-lines. All the measurements were made with the photodiodes at room temperature.The results show that the responses of the photodiodes very linear by the x-ray energy and that the energy resolution in FWHM varied between 1.9 keV and 4.4 keV for peaks corresponding to 11.9 keV to 59 keV. The BPW-34 showed the best energy resolution and the lower dark current. The full-energy peak efficiency was also determined and it was observed that the peak efficiency decreases rapidly above 50 keV. The resolution and efficiency are similar to the values obtained with other semiconductor detectors, evidencing that the photodiodes used in that study can be used as a good performance detector for low energy X-ray and gamma spectrometry. (author)

  11. 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.

  12. 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.

  13. 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

  14. 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

  15. 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.

  16. 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)

  17. Determining the platinum loading and distribution of industrial scale polymer electrolyte membrane fuel cell electrodes using low energy X-ray imaging

    DEFF Research Database (Denmark)

    Holst, T.; Vassiliev, Anton; Kerr, R.

    2014-01-01

    Low energy X-ray imaging (E <25 keV) is herein demonstrated to be a rapid, effective and non-destructive tool for the quantitative determination of the platinum loading and distribution over the entire geometric area of gas diffusion electrodes for polymer electrolyte membrane fuel cells. A linea...... of electrodes fabricated using an industrial spraying process. This technique proves to be an attractive option for the electrode performance study, the process optimization and quality control of electrode fabrication on an industrial scale....

  18. Surface structure of Bi2Se3(111) determined by low-energy electron diffraction and surface x-ray diffraction

    DEFF Research Database (Denmark)

    dos Reis, Diogo Duarte; Barreto, Lucas; Bianchi, Marco

    2013-01-01

    The surface structure of the prototypical topological insulator Bi2Se3 is determined by low-energy electron diffraction and surface x-ray diffraction at room temperature. Both approaches show that the crystal is terminated by an intact quintuple layer. Specifically, an alternative termination by ...... by a bismuth bilayer is ruled out. Surface relaxations obtained by both techniques are in good agreement with each other and found to be small. This includes the relaxation of the van der Waals gap between the first two quintuple layers....

  19. Complementary low energy ion scattering and X-ray photoelectron spectroscopy characterization of polystyrene submitted to N{sub 2}/H{sub 2} glow discharge

    Energy Technology Data Exchange (ETDEWEB)

    Bonatto, F., E-mail: bonatto02@yahoo.com.br [Instituto de Fisica, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul 91509-900 (Brazil); Rovani, S. [Universidade de Caxias do Sul, Caxias do Sul, Rio Grande do Sul 95070-560 (Brazil); Kaufmann, I.R.; Soares, G.V. [Instituto de Fisica, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul 91509-900 (Brazil); Baumvol, I.J.R. [Instituto de Fisica, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul 91509-900 (Brazil); Universidade de Caxias do Sul, Caxias do Sul, Rio Grande do Sul 95070-560 (Brazil); Krug, C. [Instituto de Fisica, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul 91509-900 (Brazil)

    2012-02-15

    Low energy ion scattering (LEIS) and X-ray photoelectron spectroscopy (XPS) were used to access the elemental composition and chemical bonding characteristics of polystyrene (PS) surfaces sequentially treated by corona and glow discharge (plasma) processing in N{sub 2}/H{sub 2} ambient. The latter has shown activity as suppressor of pathogenic Staphylococcus epidermidis biofilms. LEIS indicated that oxygen from the corona discharge process is progressively replaced by nitrogen at the PS surface. XPS shows C=N and N-C=O chemical groups as significant inhibitors of bacterial adhesion, suggesting application in medical devices.

  20. Oxidation of nanostructured Ti films produced by low energy cluster beam deposition: An X-ray Photoelectron Spectroscopy characterization

    International Nuclear Information System (INIS)

    Simone, Monica de; Snidero, Elena; Coreno, Marcello; Bongiorno, Gero; Giorgetti, Luca; Amati, Matteo; Cepek, Cinzia

    2012-01-01

    We used in-situ X-ray Photoelectron Spectroscopy (XPS) to study the oxidation process of a cluster-assembled metallic titanium film exposed to molecular oxygen at room temperature. The nanostructured film has been grown on a Si(111) substrate, in ultra high vacuum conditions, by coupling a supersonic cluster beam deposition system with an XPS experimental chamber. Our results show that upon in-situ oxygen exposure Ti 3+ is the first oxidation state observed, followed by Ti 4+ , whereas Ti 2+ is practically absent during the whole process. Our results compare well with the existing literature on Ti films produced using other techniques.

  1. 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.

  2. 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)

  3. 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

  4. 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

  5. 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.

  6. 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)

  7. 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)

  8. Low Energy X-Ray and γ-Ray Detectors Fabricated on n-Type 4H-SiC Epitaxial Layer

    Science.gov (United States)

    Mandal, Krishna C.; Muzykov, Peter G.; Chaudhuri, Sandeep K.; Terry, J. Russell

    2013-08-01

    Schottky barrier diode (SBD) radiation detectors have been fabricated on n-type 4H-SiC epitaxial layers and evaluated for low energy x- and γ-rays detection. The detectors were found to be highly sensitive to soft x-rays in the 50 eV to few keV range and showed 2.1 % energy resolution for 59.6 keV gamma rays. The response to soft x-rays for these detectors was significantly higher than that of commercial off-the-shelf (COTS) SiC UV photodiodes. The devices have been characterized by current-voltage (I-V) measurements in the 94-700 K range, thermally stimulated current (TSC) spectroscopy, x-ray diffraction (XRD) rocking curve measurements, and defect delineating chemical etching. I-V characteristics of the detectors at 500 K showed low leakage current ( nA at 200 V) revealing a possibility of high temperature operation. The XRD rocking curve measurements revealed high quality of the epitaxial layer exhibiting a full width at half maximum (FWHM) of the rocking curve 3.6 arc sec. TSC studies in a wide range of temperature (94-550 K) revealed presence of relatively shallow levels ( 0.25 eV) in the epi bulk with a density 7×1013 cm-3 related to Al and B impurities and deeper levels located near the metal-semiconductor interface.

  9. Deaths of cancer cells observed after X-Ray irradiation

    International Nuclear Information System (INIS)

    Kuwahara, Yoshikazu; Oikawa, Toshiyuki; Ochiai, Yasushi; Fukumoto, Motoi; Kurihara, Ai; Noma, Naoto; Shimura, Tsutomu; Fukumoto, Manabu; Ohkubo, Yasuhito

    2011-01-01

    Radiation induces cell death by apoptosis, autophagy (autophagic cell death, APCD), necrosis, which are respectively called type I, II, III programmed cell death, senescence, mitotic catastrophe, etc. This paper mainly describes details of authors' studies on APCD of clinically relevant radioresistant (CRR) HepG2-8960-R cells established from proliferating survivor even after repeated X-irradiation of >30 days x 2 Gy/day to the parent HepG2 cells. Autophagy forms autophagosome where many proteins are thoroughly degraded differing from proteasomal ubiquitin system, has been known essentially related to death and survival of injured cells under certain tissue conditions, and is distinguishable from other modes of cell death by morphological and cytochemical means. One of important authors' findings is as follows. APCD of CRR cells is normally seen in 20% and of the parent strain, 5%. When they are X-irradiated at 10 Gy, APCD of the latter is more (70%) than the former (40%), and no APCD is induced by 2 Gy x 5 days in the former in contrast to the latter. APCD by radiation is thus conceivably suppressed in CRR cells, suggesting that their radioresistance can be reversed by treatment to induce APCD. Autophagy is usually suppressed by mammalian target of rapamycin (mTOR), and when CRR cells are treated with rapamycin, they become radiosensitive to the comparable level to the parent HepG2. When HepG2 cells are treated with 3-methyladenine, an inhibitor of autophagy, or Beclin siRNA, they become radioresistant. For effectiveness of APCD induction and suppression on cancer therapy, results are contradictory in certain reports and autophagy should be a problem to be further elucidated from radiation biology aspect. (author)

  10. 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

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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...

  17. 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.)

  18. 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.)

  19. 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.

  20. 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.

  1. 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)

  2. 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

  3. 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.

  4. 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

  5. Quantification of 2D elemental distribution maps of intermediate-thick biological sections by low energy synchrotron μ-X-ray fluorescence spectrometry

    Science.gov (United States)

    Kump, P.; Vogel-Mikuš, K.

    2018-05-01

    Two fundamental-parameter (FP) based models for quantification of 2D elemental distribution maps of intermediate-thick biological samples by synchrotron low energy μ-X-ray fluorescence spectrometry (SR-μ-XRF) are presented and applied to the elemental analysis in experiments with monochromatic focused photon beam excitation at two low energy X-ray fluorescence beamlines—TwinMic, Elettra Sincrotrone Trieste, Italy, and ID21, ESRF, Grenoble, France. The models assume intermediate-thick biological samples composed of measured elements, the sources of the measurable spectral lines, and by the residual matrix, which affects the measured intensities through absorption. In the first model a fixed residual matrix of the sample is assumed, while in the second model the residual matrix is obtained by the iteration refinement of elemental concentrations and an adjusted residual matrix. The absorption of the incident focused beam in the biological sample at each scanned pixel position, determined from the output of a photodiode or a CCD camera, is applied as a control in the iteration procedure of quantification.

  6. 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

  7. 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.)

  8. 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)

  9. 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)

  10. 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

  11. 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

  12. 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.

  13. 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).

  14. Prominent soft x-ray lines of Sr-like Au41+ in low-energy EBIT spectrum

    International Nuclear Information System (INIS)

    Vilkas, Marius Jonas; Ishikawa, Yasuyuki; Traebert, Elmar

    2007-01-01

    Relativistic multireference Moeller-Plesset perturbation theory has been employed to calculate with high accuracy the energy levels and transition probabilities of Cu- to Sr-like gold ions. The many-body calculations were carried out to identify the unassigned blended lines in the 35-40 A region of the low-energy EBIT spectrum of the gold ions [Traebert et al 2001 Can. J. Phys.79153]. Most of the prominent lines in the 35-40 A region were identified as the emission lines in Sr-like gold

  15. 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.

  16. Radioprotective effect of Ganoderma lucidum (Leyss. ex. Fr. ) Karst after X-ray irradiation in mice

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, H.Y.; Lian, S.L.; Lin, C.C. (Kaohsiung Medical College (Taiwan))

    1990-01-01

    Six to seven week old male mice of ICR strain were exposed to 500 or 650 cGy of X-ray during experiments to determine if Ganoderma lucidum could be a factor in modification of radiation damage. Continuous intraperitoneal injection of the extract from Ganoderma lucidum before or after irradiation of 500 and 650 cGy of X-ray was found to improve the 30-day survival fractions of ICR mice, but wasn't significant by statistical analysis. The administration also enhanced the recoveries of the body weights and increased the recovery of hemograms of irradiated mice from radiation damage by injecting before or after radiation exposure, especially for the treatment of 500 cGy irradiation. The 10-day CFUs was significantly higher for Ganoderma lucidum treated groups than for untreated groups. However, the differences of radioprotective effect between the X-ray irradiated groups with Ganoderma lucidum pretreated and post-treated were not significant (p greater than 0.05).

  17. 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.

  18. Radioprotective effect of Ganoderma lucidum (Leyss. ex. Fr.) Karst after X-ray irradiation in mice

    International Nuclear Information System (INIS)

    Hsu, H.Y.; Lian, S.L.; Lin, C.C.

    1990-01-01

    Six to seven week old male mice of ICR strain were exposed to 500 or 650 cGy of X-ray during experiments to determine if Ganoderma lucidum could be a factor in modification of radiation damage. Continuous intraperitoneal injection of the extract from Ganoderma lucidum before or after irradiation of 500 and 650 cGy of X-ray was found to improve the 30-day survival fractions of ICR mice, but wasn't significant by statistical analysis. The administration also enhanced the recoveries of the body weights and increased the recovery of hemograms of irradiated mice from radiation damage by injecting before or after radiation exposure, especially for the treatment of 500 cGy irradiation. The 10-day CFUs was significantly higher for Ganoderma lucidum treated groups than for untreated groups. However, the differences of radioprotective effect between the X-ray irradiated groups with Ganoderma lucidum pretreated and post-treated were not significant (p greater than 0.05)

  19. 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)

  20. 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)

  1. 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

  2. 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.

  3. 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

  4. X-ray irradiation of RC-MAP pre-stored for various numbers of days. Effect of X-ray irradiation on RC-MAP and reuse of RC-MAP after irradiation

    International Nuclear Information System (INIS)

    Yamada, Naotomo; Nagumo, Fumio; Kawasaki, Seiji; Matsuzaki, Miwako; Tadano, Jutaro

    1995-01-01

    X-ray irradiation is currently in wide use as a means of preventing post-transfusion graft-versus-host disease (PT-GVHD). In this study, we evaluated the effects of X-ray irradiation on RC-MAP pre-stored for various numbers of days, and assessed how long irradiated RC-MAP can be stored. RC-MAP was irradiated at a dosage of 15 Gy at 1, 7, 14, 21 or 28 days after blood collection. These specimens were referred to as group I, II, III, IV and V (X-ray-irradiated groups), respectively. Non-irradiated RC-MAP was used as the control. Results showed that plasma K concentration increased after X-ray irradiation. It is therefore advisable that RC-MAPs be used immediately in infants and in renal failure. However, to maximize the efficiency of blood product use, it seemed possible that groups I and II could be used within two weeks after irradiation, and group III within one week. On the basis of this increase in K concentration, however, groups IV and V plasma should be used immediately after irradiation. (author)

  5. 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)

  6. An X-Ray facility to perform irradiation tests and TID studies on electronics and detectors

    CERN Document Server

    Brundu, Davide; Cadeddu, Sandro; Wyllie, Ken; Ciambrone, Paolo

    2018-01-01

    The X-Ray irradiation system of the LHCb group, installed in Cagliari, is presented; with a particular focus on the setup configuration and dose rate calibration. The system can be used to perform Total Ionizing Dose (TID) studies for detectors, readout and front-end electronics. It was already used to test the nSYNC chip, an ASIC for the readout of the LHCb upgraded muon system.

  7. 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

  8. 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

  9. 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.

  10. Industrial X-ray imaging based on scintillators and CMOS APS array: direct X-ray irradiation effects

    International Nuclear Information System (INIS)

    Kim, Kwang Hyun; Jeon, Sung Chae; Kim, Young Soo; Cho, Gyuseong

    2005-01-01

    To see the effects of the direct X-ray in a Lanex screen-coupled CMOS APS imager, we measured modulation transfer function (MTF), noise power spectrum (NPS), and detective quantum efficiency (DQE). These measurements were performed under the condition of non-destructive test (NDT). By increasing the cumulative exposure on the imager, the MTF was degraded, and also leading to the DQE degradation. Each parameter changed by the exposure is described in detail

  11. 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.)

  12. 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

  13. 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

  14. 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

  15. 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.

  16. Challenges in validating radiation sterilization with low energy electron irradiation

    International Nuclear Information System (INIS)

    Miller, A.; Helt-Hansen, J.

    2011-01-01

    Complete text of publication follows. Low energy electron irradiation (80-300 keV) is used increasingly for sterilization or decontamination in connection with isolators for aseptic filling lines in the pharmaceutical industry. It is not defined how validation for this process shall be carried out. A method can be derived from the medical device standard for radiation sterilization, ISO 11137, because the principles described in this standard can be applied to almost any industrial irradiation process. The validations elements are: Process definition, concerning specification of the dose required for the process and the maximum acceptable dose for the product. Installation qualification, concerning acceptance the irradiation facility. Operational qualification, concerning characterization of the facility. Performance qualification, concerning setting up the process. Process control, concerning routine monitoring. The limited penetration of the low energy electrons leads to problems with respect to executing these validation steps. This paper discusses these problems, and shows with examples how they can be solved.

  17. Bone fragility induced by X-ray irradiation in relation to cortical bone-mineral content

    International Nuclear Information System (INIS)

    Nyaruba, M.M.; Yamamoto, I.; Morita, R.; Kimura, H.

    1998-01-01

    The purpose of this study was to investigate the effects of fractional irradiation on the biomechanical properties of bone in the rat in relation to the cortical bone-mineral content (BMC), and to compare these effects with those brought about by single-dose irradiation. Seventy-five veteran female Wistar rats were divided into 4 groups. Group 1 was the control group. The left tibiae of the remaining rats were exposed to irradiation. Group 2 received one single dose of X-rays at 10-60 Gy. Groups 3 and 4 received fractional irradiation up to different cumulative doses (10-60 Gy): group 3 received 2.5 Gy once a day; group 4 received 1.25 Gy twice a day. Twenty-four weeks after irradiation, the rats were killed and the BMC in each tibial diaphysis was determined by dual-energy X-ray absorptiometry (DXA). The bones were then loaded to failure in a three-point bending test. The control group showed no difference (p>0.05) between left and right tibiae, neither in BMC nor in the maximum load at fracture. Single-dose irradiation caused a 16% (p=0.0366) decrease in the maximum load at 40 Gy, and a 19% (p=0.008) decrease at 60 Gy. The once-daily fractional dose of irradiation caused a 10% (p=0.0022) decrease in the maximum load of the irradiated tibiae at 60 Gy when compared to the intact contralateral tibiae. The twice-daily fractional dose of irradiation had no observable effect on the maximum load of the irradiated tibiae. Neither fractional irradiation modality had an effect on BMC. (orig./MG)

  18. 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.

  19. 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

  20. TU-AB-BRC-07: Efficiency of An IAEA Phase-Space Source for a Low Energy X-Ray Tube Using Egs++

    Energy Technology Data Exchange (ETDEWEB)

    Watson, PGF; Renaud, MA; Seuntjens, J [McGill University, Montreal, Quebec (Canada)

    2016-06-15

    Purpose: To extend the capability of the EGSnrc C++ class library (egs++) to write and read IAEA phase-space files as a particle source, and to assess the relative efficiency gain in dose calculation using an IAEA phase-space source for modelling a miniature low energy x-ray source. Methods: We created a new ausgab object to score particles exiting a user-defined geometry and write them to an IAEA phase-space file. A new particle source was created to read from IAEA phase-space data. With these tools, a phase-space file was generated for particles exiting a miniature 50 kVp x-ray tube (The INTRABEAM System, Carl Zeiss). The phase-space source was validated by comparing calculated PDDs with a full electron source simulation of the INTRABEAM. The dose calculation efficiency gain of the phase-space source was determined relative to the full simulation. The efficiency gain as a function of i) depth in water, and ii) job parallelization was investigated. Results: The phase-space and electron source PDDs were found to agree to 0.5% RMS, comparable to statistical uncertainties. The use of a phase-space source for the INTRABEAM led to a relative efficiency gain of greater than 20 over the full electron source simulation, with an increase of up to a factor of 196. The efficiency gain was found to decrease with depth in water, due to the influence of scattering. Job parallelization (across 2 to 256 cores) was not found to have any detrimental effect on efficiency gain. Conclusion: A set of tools has been developed for writing and reading IAEA phase-space files, which can be used with any egs++ user code. For simulation of a low energy x-ray tube, the use of a phase-space source was found to increase the relative dose calculation efficiency by factor of up to 196. The authors acknowledge partial support by the CREATE Medical Physics Research Training Network grant of the Natural Sciences and Engineering Research Council (Grant No. 432290).

  1. 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

  2. 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.)

  3. 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)

  4. 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

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. 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)

  10. 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)

  11. 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

  12. 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

  13. 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)

  14. Setup for in situ x-ray diffraction study of swift heavy ion irradiated materials.

    Science.gov (United States)

    Kulriya, P K; Singh, F; Tripathi, A; Ahuja, R; Kothari, A; Dutt, R N; Mishra, Y K; Kumar, Amit; Avasthi, D K

    2007-11-01

    An in situ x-ray diffraction (XRD) setup is designed and installed in the materials science beam line of the Pelletron accelerator at the Inter-University Accelerator Centre for in situ studies of phase change in swift heavy ion irradiated materials. A high vacuum chamber with suitable windows for incident and diffracted X-rays is integrated with the goniometer and the beamline. Indigenously made liquid nitrogen (LN2) temperature sample cooling unit is installed. The snapshots of growth of particles with fluence of 90 MeV Ni ions were recorded using in situ XRD experiment, illustrating the potential of this in situ facility. A thin film of C60 was used to test the sample cooling unit. It shows that the phase of the C60 film transforms from a cubic lattice (at room temperature) to a fcc lattice at around T=255 K.

  15. Setup for in situ x-ray diffraction study of swift heavy ion irradiated materials

    Science.gov (United States)

    Kulriya, P. K.; Singh, F.; Tripathi, A.; Ahuja, R.; Kothari, A.; Dutt, R. N.; Mishra, Y. K.; Kumar, Amit; Avasthi, D. K.

    2007-11-01

    An in situ x-ray diffraction (XRD) setup is designed and installed in the materials science beam line of the Pelletron accelerator at the Inter-University Accelerator Centre for in situ studies of phase change in swift heavy ion irradiated materials. A high vacuum chamber with suitable windows for incident and diffracted X-rays is integrated with the goniometer and the beamline. Indigenously made liquid nitrogen (LN2) temperature sample cooling unit is installed. The snapshots of growth of particles with fluence of 90MeV Ni ions were recorded using in situ XRD experiment, illustrating the potential of this in situ facility. A thin film of C60 was used to test the sample cooling unit. It shows that the phase of the C60 film transforms from a cubic lattice (at room temperature) to a fcc lattice at around T =255K.

  16. 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.

  17. 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

  18. Low-energy electron irradiation assisted diffusion of gold nanoparticles in polymer matrix

    International Nuclear Information System (INIS)

    Deore, Avinash V.; Bhoraskar, V.N.; Dhole, S.D.

    2014-01-01

    A simple and controllable method to synthesize nanoparticles in the surface region of polymers was used by low energy electron irradiation. Using this method, gold nanoparticles have been synthesized by irradiating gold coated PVA (Polyvinyl Alcohol) sheets. This method was easy in operation and even period of few minutes was sufficient to obtain the nanoparticles. The coatings (∼10 μm) made from a mixture of ethanol and HAuCl 4 on PVA sheets (∼150 μm) by simple drop cast method were irradiated with 30 keV electrons, at room temperature and 10 −6 mbar vacuum level. The electron fluence was varied from coating to coating in the range of 0 to 24×10 15 e/cm 2 . The irradiated samples were characterized by the UV–Vis, XRD, SEM and RBS techniques. The plasmon absorption peak at ∼539 nm in UV–Vis spectra was an evidence for the initiation of the growth of gold nanoparticles. The X-ray diffraction results and the blue shift in the plasmon absorption peak reveal that the size of nanoparticles could be tailored in the range from 58 to 40 nm by varying the electron fluence. The diffusion of gold in the PVA was confirmed by the Rutherford backscattering spectroscopy and scanning electron microscopy techniques. This method of synthesis of metal nanoparticles by low energy electron beam irradiation has the key importance in the development of new fabrication techniques for nanomaterials. - Highlights: • The results indicate that low energy electrons can effectively be used for the synthesis of nanoparticles of different sizes. • This study leads to a definite conclusion that gold nanoparticles have been synthesized in surface region of the PVA sheet. • The size of nanoparticles decreases with increasing electron fluence. • The depth of diffusion of Au atoms at maximum fluence was found to be ∼1.5 μm

  19. 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

  20. 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).

  1. 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)

  2. Low energy He+ irradiation effect on graphite surface

    International Nuclear Information System (INIS)

    Asari, E.; Nakamura, K.G.; Kitajima, M.; Kawabe, T.

    1992-01-01

    Study on the lattice disordering and the secondary electron emission under low energy (1-5keV) He + irradiation is reported. Real-time Raman measurements show that difference in the observed Raman spectra for different ion energies is due to the difference of the damage depth. The relation between the observed Raman spectrum and the depth profile of lattice damage is discussed. Energy dependence of the secondary electron emission coefficient are also described. (author)

  3. 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.

  4. SU-E-T-537: Comparison of Intra-Operative Soft X-Rays to Low Energy Electron Beams for Treatment of Superficial Lesions

    International Nuclear Information System (INIS)

    Chinsky, B; Diak, A; Gros, S; Sethi

    2014-01-01

    Purpose: Superficial soft x-ray applicators have recently been designed for use with existing intra-operative radiotherapy systems. These applicators may be used in treating superficial lesions which are conventionally treated with electron beams. The purpose of this abstract is to compare dose distributions of an intra-operative 50kV x-ray unit with low energy electrons for the treatment of superficial lesions. Methods: Dosimetric parameters for 1 and 3-cm diameter Intrabeam superficial x-ray applicators were measured with EBT3 Gafchromic film in a solid water phantom. Depth dose distributions and profiles (d=2, 5, 10 and 15mm) were obtained by prescribing a dose of 400cGy at 5mm depth below the phantom surface. Corresponding dose profiles for 6-MeV electrons were acquired from a Varian Clinac 21EX at 100 SSD. H and D calibration curves were generated for each modality for 0-800cGy. Results: Dose coverage, penumbra, dose uniformity, surface dose, and dose fall-off were examined. Compared to electrons, Intrabeam lateral dose coverage at 5mm depth was 70% larger with a much sharper (1/4) penumbra. Electron isodose levels bulged with depth, whereas Intrabeam isodose levels exhibited a convex cone shape. The Intrabeam dose profiles demonstrated horns in the dose distribution up to a 5mm depth and an exponential dose fall-off. Relative surface dose was higher for the Intrabeam applicators. Treatment times were comparable for both modalities. Conclusions: The very small penumbra of Intrabeam at shallow depths could be useful in treating superficial lesions adjacent to critical structures. The exponential dose fall-off of Intrabeam makes it appealing in the sparing of structures beyond the lesion. However, for lesions past a depth of 5mm, electrons would be desirable as they penetrate farther and provide skin sparing. Intrabeam may be preferable for sites that are difficult to treat with electrons due to mechanical and physical limitations

  5. 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.

  6. 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

  7. Dose controlled low energy electron irradiator for biomolecular films.

    Science.gov (United States)

    Kumar, S V K; Tare, Satej T; Upalekar, Yogesh V; Tsering, Thupten

    2016-03-01

    We have developed a multi target, Low Energy Electron (LEE), precise dose controlled irradiator for biomolecular films. Up to seven samples can be irradiated one after another at any preset electron energy and dose under UHV conditions without venting the chamber. In addition, one more sample goes through all the steps except irradiation, which can be used as control for comparison with the irradiated samples. All the samples are protected against stray electron irradiation by biasing them at -20 V during the entire period, except during irradiation. Ethernet based communication electronics hardware, LEE beam control electronics and computer interface were developed in house. The user Graphical User Interface to control the irradiation and dose measurement was developed using National Instruments Lab Windows CVI. The working and reliability of the dose controlled irradiator has been fully tested over the electron energy range of 0.5 to 500 eV by studying LEE induced single strand breaks to ΦX174 RF1 dsDNA.

  8. Dose controlled low energy electron irradiator for biomolecular films

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, S. V. K., E-mail: svkk@tifr.res.in; Tare, Satej T.; Upalekar, Yogesh V.; Tsering, Thupten [Tata Institute of Fundamental Research, Homi Bhabha Road, Colaba, Mumbai 400 005 (India)

    2016-03-15

    We have developed a multi target, Low Energy Electron (LEE), precise dose controlled irradiator for biomolecular films. Up to seven samples can be irradiated one after another at any preset electron energy and dose under UHV conditions without venting the chamber. In addition, one more sample goes through all the steps except irradiation, which can be used as control for comparison with the irradiated samples. All the samples are protected against stray electron irradiation by biasing them at −20 V during the entire period, except during irradiation. Ethernet based communication electronics hardware, LEE beam control electronics and computer interface were developed in house. The user Graphical User Interface to control the irradiation and dose measurement was developed using National Instruments Lab Windows CVI. The working and reliability of the dose controlled irradiator has been fully tested over the electron energy range of 0.5 to 500 eV by studying LEE induced single strand breaks to ΦX174 RF1 dsDNA.

  9. 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.

  10. High-precision radiosurgical dose delivery by interlaced microbeam arrays of high-flux low-energy synchrotron X-rays.

    Directory of Open Access Journals (Sweden)

    Raphaël Serduc

    Full Text Available Microbeam Radiation Therapy (MRT is a preclinical form of radiosurgery dedicated to brain tumor treatment. It uses micrometer-wide synchrotron-generated X-ray beams on the basis of spatial beam fractionation. Due to the radioresistance of normal brain vasculature to MRT, a continuous blood supply can be maintained which would in part explain the surprising tolerance of normal tissues to very high radiation doses (hundreds of Gy. Based on this well described normal tissue sparing effect of microplanar beams, we developed a new irradiation geometry which allows the delivery of a high uniform dose deposition at a given brain target whereas surrounding normal tissues are irradiated by well tolerated parallel microbeams only. Normal rat brains were exposed to 4 focally interlaced arrays of 10 microplanar beams (52 microm wide, spaced 200 microm on-center, 50 to 350 keV in energy range, targeted from 4 different ports, with a peak entrance dose of 200Gy each, to deliver an homogenous dose to a target volume of 7 mm(3 in the caudate nucleus. Magnetic resonance imaging follow-up of rats showed a highly localized increase in blood vessel permeability, starting 1 week after irradiation. Contrast agent diffusion was confined to the target volume and was still observed 1 month after irradiation, along with histopathological changes, including damaged blood vessels. No changes in vessel permeability were detected in the normal brain tissue surrounding the target. The interlacing radiation-induced reduction of spontaneous seizures of epileptic rats illustrated the potential pre-clinical applications of this new irradiation geometry. Finally, Monte Carlo simulations performed on a human-sized head phantom suggested that synchrotron photons can be used for human radiosurgical applications. Our data show that interlaced microbeam irradiation allows a high homogeneous dose deposition in a brain target and leads to a confined tissue necrosis while sparing

  11. 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)

  12. Measurements of laser generated soft X-ray emission from irradiated gold foils

    Energy Technology Data Exchange (ETDEWEB)

    Davis, J. S.; Keiter, P. A.; Klein, S. R.; Drake, R. P.; Shvarts, D. [University of Michigan, 2455 Hayward St., Ann Arbor, Michigan 48109 (United States); Frank, Y.; Raicher, E.; Fraenkel, M. [Soreq Nuclear Research Center, Yavne (Israel)

    2016-11-15

    Soft x-ray emission from laser irradiated gold foils was measured at the Omega-60 laser system using the Dante photodiode array. The foils were heated with 2 kJ, 6 ns laser pulses and foil thicknesses were varied between 0.5, 1.0, and 2.0 μm. Initial Dante analysis indicates peak emission temperatures of roughly 100 eV and 80 eV for the 0.5 μm and 1.0 μm thick foils, respectively, with little measurable emission from the 2.0 μm foils.

  13. Indirect (x-ray) irradiation of encapsulated microtargets in the Iskra-5 facility

    International Nuclear Information System (INIS)

    Abzaev, F.M.; Bel'kov, S.A.; Bessarab, A.V.; Bondarenko, S.V.; Gaidash, V.A.; Garanin, S.G.; Dolgoleva, G.V.; Zhidkov, N.V.; Izgorodin, V.M.; Kirillov, G.A.; Kochemasov, G.G.; Litvin, D.N.; Martynenko, S.P.; Murugov, V.M.; Mkhitar'yan, L.S.; Pinegin, A.V.; Petrov, S.I.; Senik, A.V.; Suslov, N.A.; Bushuev, V.S.

    1998-01-01

    Experiments on the indirect (x-ray) irradiation of high-aspect-ratio capsules (with a diameter-to-thickness ratio ≅900) filled with DT gas are performed on the Iskra-5 laser facility. It is shown that all the characteristics measured (neutron yield, ion temperature, shell implosion time, etc.) are faithfully reproduced in calculations based on the one-dimensional SNDA (spectral nonequilibrium diffusion of absorption) program for nonequilibrium radiation gas dynamics. The calculations provide an explanation for the experimentally detected generation of a smaller number of neutrons in an experiment with a higher measured value for the ion temperature of DT gas

  14. EPR study of electron traps in x-ray-irradiated yttria-stabilized zirconia

    International Nuclear Information System (INIS)

    Azzoni, C.B.; Paleari, A.

    1989-01-01

    Single crystals of yttria-stabilized zirconia (12 mol % of Y 2 O 3 ) have been x-ray irradiated at room temperature. The electron paramagnetic resonance spectrum of the filled electron traps is analyzed in terms of a single oxygen vacancy type of defect with its symmetry axis along the left-angle 111 right-angle direction. The angular dependence of the linewidth and the asymmetry of the line shape are attributed to the disordered rearrangements of the anion sublattice surrounding the oxygen vacancy. This affects the local crystal fields and the directions of the symmetry axis of the defects

  15. EPR study of electron traps in x-ray-irradiated yttria-stabilized zirconia

    Energy Technology Data Exchange (ETDEWEB)

    Azzoni, C.B.; Paleari, A. (Dipartimento di Fisica, Alessandro Volta dell' Universita di Pavia, via Bassi 6, 27100 Pavia, Italy (IT))

    1989-10-01

    Single crystals of yttria-stabilized zirconia (12 mol % of Y{sub 2}O{sub 3}) have been x-ray irradiated at room temperature. The electron paramagnetic resonance spectrum of the filled electron traps is analyzed in terms of a single oxygen vacancy type of defect with its symmetry axis along the {l angle}111{r angle} direction. The angular dependence of the linewidth and the asymmetry of the line shape are attributed to the disordered rearrangements of the anion sublattice surrounding the oxygen vacancy. This affects the local crystal fields and the directions of the symmetry axis of the defects.

  16. X-ray topographic investigation of the deformation field around spots irradiated by FLASH single pulses

    Czech Academy of Sciences Publication Activity Database

    Wierzchowski, W.; Wieteska, K.; Balcer, T.; Klinger, D.; Sobierajski, R.; Zymierska, D.; Chalupský, Jaromír; Hájková, Věra; Burian, Tomáš; Gleeson, A.J.; Juha, Libor; Tiedtke, K.; Toleikis, S.; Vyšín, Luděk; Wabnitz, H.; Gaudin, J.

    2011-01-01

    Roč. 80, č. 10 (2011), s. 1036-1040 ISSN 0969-806X R&D Projects: GA AV ČR KAN300100702; GA MŠk LC510; GA ČR(CZ) GAP108/11/1312; GA MŠk(CZ) LC528; GA MŠk LA08024; GA AV ČR IAAX00100903; GA MŠk(CZ) ME10046 Institutional research plan: CEZ:AV0Z10100523 Keywords : silicon * FLASH irradiation * x-ray topography * deformation fields Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.227, year: 2011

  17. Effects of low-dose continuously fractionated X-ray irradiation on murine peripheral blood lymphocytes

    International Nuclear Information System (INIS)

    Xie Yi; Zhang Hong; Dang Bingrong; Hao Jifang; Guo Hongyun; Wang Xiaohu

    2007-01-01

    For estimating biological risks from low doses continual irradiation, we investigated the effects of exposure to continuously fractionated X-rays on murine immune system. The BALB/c mice were irradiated with 0.07Gy at the first day and 0.08 Gy/d in the following 12 days at a dose rate of 0.2 Gy/min. The peripheral blood lymphocyte cycle and death were determined by flow cytometry at the cumulative doses of 0, 0.07, 0.23, 0.39, 0.55, 0.71, 0.87 and 1.03 Gy respectively. The results showed that the cycle of peripheral blood lymphocyte was arrested in G 0 /G 1 at cumulative doses of 0.07, 0.23, 0.71 and 0.87 Gy, and in G 2 /M at cumulative doses of 0.39 and 1.03 Gy; the percentage of death of peripheral blood lymphocyte was ascended with dose increasing, and reached the death peak at cumulative doses of 0.71 Gy. The results suggested that low doses continual X-rays total-body irradiated could result in changes of cellular cycle and death, and some damages to immunocytes, which accorded to linear square model. (authors)

  18. 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

  19. X-RAY IRRADIATION OF H{sub 2}O + CO ICE MIXTURES WITH SYNCHROTRON LIGHT

    Energy Technology Data Exchange (ETDEWEB)

    Jiménez-Escobar, A.; Ciaravella, A.; Micela, G.; Cecchi-Pestellini, C. [INAF–Osservatorio Astronomico di Palermo, P.za Parlamento 1, I-90134 Palermo (Italy); Chen, Y.-J.; Huang, C.-H., E-mail: jimenezea@astropa.inaf.it, E-mail: ciarave@astropa.inaf.it, E-mail: giusi@astropa.inaf.it, E-mail: cecchi-pestellini@astropa.inaf.it, E-mail: asperchen@phy.ncu.edu.tw, E-mail: 101222023@cc.ncu.edu.tw [Department of Physics, National Central University, Jhongli District, Taoyuan City 32054, Taiwan (China)

    2016-03-20

    We irradiated a (4:1) mixture of water and carbon monoxide with soft X-rays of energies up to 1.2 keV. The experiments were performed using the spherical grating monochromator beamline at National Synchrotron Radiation Research Center in Taiwan. Both monochromatic (300 and 900 eV) and broader energy fluxes (250–1200 eV) were employed. During the irradiation, the H{sub 2}O + CO mixture was ionized, excited, and fragmented, producing a number of reactive species. The composition of the ice has been monitored throughout both the irradiation and warm-up phases. We identified several products, which can be related through a plausible chemical reaction scheme. Such chemistry is initiated by the injection of energetic photoelectrons that produce multiple ionization events generating a secondary electron cascade. The results have been discussed in light of a model for protoplanetary disks around young solar-type stars.

  20. 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

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. 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

  6. 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)

  7. 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)

  8. 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

  9. Degradation and crosslinking of perfluoroalkyl polyethers under X-ray irradiation in ultrahigh vacuum

    International Nuclear Information System (INIS)

    Mori, S.; Morales, W.

    1989-03-01

    Degradation of three types of commercially available perfluoroalkyl polyethers (PFPE)-Demnum S200, Fomblin Z25, and Krytox 16256-by X-ray irradiation was studied by using X-ray photoemission spectroscopy (XPS) and a mass spectrometer under ultra-high-vacuum conditions. The carbons in the polymers were characterized by chemical shifts of Cls binding energies. Gaseous products containing COF2 and low-molecular-weight fluorocarbons were formed. From Fomblin Z25, which has acetal linkages (-OCF2O-), a large quantity of COF2 gas was evolved. Liquid products became tacky after a long irradiation time, and some did not dissolve in Freon. High-pressure liquid chromatography (HPLC) showed that molecular weight distribution became broader and that higher molecular weight polymers were formed from Demnum and Krytox. We concluded from these results that degradation and cross-linking took place simultaneously. Demnum crosslinked more easily than the other fluids. The time dependence of both XPS spectra of Cls and mass spectra showed that C-O-bonded carbons in PFPE'S were removed faster than other carbons. There was no substrate effect on the degradation reaction because the first-order rate constants calculated from the change of gaseous products were similar when stainless steel (440C) and gold-coated surfaces were used. Metal fluorides were formed on stainless steel during the reaction. A mechanism for the degradation of PFPE'S is discussed on the basis of their molecular structures

  10. 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.

  11. 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)

  12. Dose characterization of the rad sourceTM 2400 X-ray irradiator for oyster pasteurization

    International Nuclear Information System (INIS)

    Wagner, Jennifer Koop; Dillon, Jeff A.; Blythe, Eugene K.; Ford, John R.

    2009-01-01

    The RS 2400's cylindrical X-ray source yields dose rates high enough to allow the irradiator to replace widely used gamma irradiators. Except for the leftmost 5 cm, beam uniformity is within 10% at the tube surface. At maximum operating parameters, the beam has HVL 1 =13.66 mm aluminum, HC=0.47, and hν eq =88.5 keV. Maximum dose rates to tissue are 65 Gy min -1 ±3.1% at tube surface, 37 Gy min -1 ±3.1% at center of canisters, 14.1 Gy min -1 ±6.5% for thin-shelled oysters, and 12.3 Gy min -1 ±6.2% for thick-shelled oysters

  13. 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)

  14. 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.)

  15. 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)

  16. 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.

  17. 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)

  18. 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)

  19. Changes in ultrastructure of rat ovaries after early postnatal x-ray irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Matsumoto, A [Juntendo Univ., Tokyo (Japan). School of Medicine

    1975-02-01

    Female rats were irradiated with 190R of X-rays at 10 days of age and the ovarian ultrastructures were studied 4 and 7 months after irradiation. Ultrastructural changes were found in germinal epithelial cells, in fibroblasts in the tunica albuginea and in interstitial cells. The germinal epithelial cells exhibited various signs of degeneration but no sign of proliferation. Electron density of their basal part was reduced considerably. Their mitochondria became swollen and free ribosomes were decreased in number. The nuclei often protruded from the free surface of these cells. These cells frequently fragmented and, finally, complete desquamation occurred. The basement membrane became unevently thickened. Nuclei of enlarged fibroblasts in the tunica albuginea became irregularly ellipsoid in shape, and the nuclear envelope was occasionally invaginated. Various cytoplasmic organelles of the fibroblasts were well-developed. Some abnormal invasion of cytoplasm into the nucleus was found in the interstitial cells showing the ultrastructural characteristics of steroid hormone synthesis. Various cytoplasmic roganelles and inclusions invaded into the nuclei of these cells and the nuclear envelope sometimes disappeared locally. These interstitial cells contained a large number of irregular-shaped electron dense mitochondria with vesicular cristae, and numerous dilated vesicles of smooth-surfaced endoplasmic reticulum (SER). The cells of the anovular follicles in the irradiated ovaries resembled, in fine structure, the granulosa cells in normal primary follicles of non-irradiated ovaries. These cells seemed to be less affected by early postnatal irradiation.

  20. 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.

  1. 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

  2. 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.

  3. Electron channeling X-ray microanalysis for cation configuration in irradiate magnesium alimate spinel

    International Nuclear Information System (INIS)

    Matsumura, S.; Soeda, T.; Zaluzec, N. J.; Kinoshita, C.

    1999-01-01

    High angular resolution electron channeling X-ray spectroscopy (HARECXS) was examined as a practical tool to locate lattice-ions in spinel crystals. The orientation dependent intensity distribution of emitted X-rays obtained by HARECXS is so sensitive to lattice-ion configuration in the illuminated areas that the occupation probabilities on specific positions in the crystal lattice can be determined accurately through comparison with the theoretical rocking curves. HARECXS measurements have revealed partially disordered cation arrangement in MgO·nAl 2 O 3 with n = 1.0 and 2.4. Most Al 3+ lattice-ions occupy the octahedral (VIII) sites, while Mg 2 lattice-ions reside on both the tetrahedral (IV) and the octahedral (VIII) sites. The structural vacancies are enriched in the IV-sites. Further evacuation of cations from the IV-sites to the VIII-sites is recognized in a disordering process induced by irradiation with 1 MeV Ne + ions up to 8.9 dpa at 870 K

  4. 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

  5. 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.)

  6. 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

  7. Anomalous small-angle x-ray scattering of a femtosecond irradiated germano silicate fibre preform.

    Energy Technology Data Exchange (ETDEWEB)

    Hindle, F.; Fertein, E.; Seifert, S.; Przygodski, C.S.; Bocquet, R.; Douay, M.; Bychkov, E.; Experimental Facilities Division (APS); LPCA, CNRS; PhLAM; Univ. des Sciences et Tech. de Lille

    2005-01-01

    RADIATION is shown to induce significant mesoscopic structure. The scattering intensity for irradiated glasses is close to two orders of magnitude greater than that of unexposed material. Anomalous small-angle X-ray scattering (ASAXS) around the germanium K-edge for the silica and germanium doped silica regions of a fiber preform is used to demonstrate that identical structures are induced in both glass materials, with germanium displaying a capacity to isomorphically replace silicon in the case of the germanium doped silica. Analysis of measured scattering indicates that photo-inscribed features are produced at two distinct scales with typical radii of R {approx} 20 Angstroms and R{sub min} {approx} 200 Angstroms.

  8. ESR dosimetry below 1 Gy, in X-ray irradiated tooth enamel

    International Nuclear Information System (INIS)

    Fainstein, Carlos; Winkler, Elin

    2000-01-01

    Tooth enamel, extracted from molars, was irradiated with 66 keV X-rays, with doses up to 1 Gy. The preparation of the powder samples is described, as well as the protocol for the acquisition and processing of the spectra. The radiation induced paramagnetism is measured, at room temperature, by ESR Spectroscopy. The ESR spectra is well described considering two paramagnetic species, with magnetic moments (in units of Bohr magneton) g=2,0041, and g 1 =2,0018, g 2 =1,9972. The ESR data (peak-to-peak amplitude per mg, hpp/mg, vs dose D), for doses 0 Gy 2 =0,996) with the linear expression: [hpp/mg] = -0,2(0,4)+14,9(0,5). D [Gy]. The result supports the growing confidence in the use of this material, and method, in Retrospective Dosimetry. (author)

  9. ESR Dosimetry Below 1 Gy, in X-Ray Irradiated Tooth Enamel

    International Nuclear Information System (INIS)

    Fainstein, Carlos; Winkler, E; Dubner, D; Gisone, P; Perez, M.R; Saravi, M; Alvarez, P; Davila, F

    2000-01-01

    Tooth enamel, extracted from molars, was irradiated with 66keV X-rays, with doses up to 1Gy.The preparation of the powder samples is described, as well as the protocol for the acquisition and processing of the spectra.The radiation induced paramagnetism is measured, at room temperature, by ESR Spectroscopy.The ESR spectra is well described considering two paramagnetic species, with magnetic moments (in units of Bohr magnetons) g=2,0041, and g1=2,0018, g2=1,9972.The ESR data (peak-to-peak amplitude per mg, hpp/mg, vs dose D), for doses 0Gy 2 =0,996) with the linear expression: [hpp/mg] = -0,2( 0,4)+14,9(0,5). D [Gy].The result supports the growing confidence in the use of this material, and method, in Retrospective Dosimetry

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

    Directory of Open Access Journals (Sweden)

    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.

  11. Study of human blood and hemocomponents irradiated by low angle x ray scattering (LAXS)

    Energy Technology Data Exchange (ETDEWEB)

    Pinto, Nivia G. Villela; Barroso, Regina C. [Universidade do Estado do Rio de Janeiro (UERJ), RJ (Brazil). Inst. de Fisica. Dept. de Fisica Aplicada e Termodinamica], e-mail: nitatag@gmail.com; Mota, Carla L.S.; Almeida, Andre P.; Azeredo, Soraia R.; Braz, Delson [Coordenacao dos Programas de Pos-graduacao em Engenharia (COPPE/UFRJ), RJ (Brazil). Lab. de Instrumentacao Nuclear], e-mail: delson@lin.ufrj.br

    2009-07-01

    Irradiation of blood and blood components is currently practiced in developed and in a few developing countries. The main purpose of this process is the prevention of graft versus host disease in immunodeficient patients. The Food and Drug Administration recommends a dose range of 15 Gy to 25 Gy for these blood components. When x-ray photons are scattered from biological samples, their angular distribution shows one or more peaks in the forward direction of scattering. These peaks are characteristic for the investigated samples. Due to its wide range of biological and medical applications, low-angle x-ray scattering has attracted the attention of many authors. Thus in this present work was studied the possible variations in scattering profiles due to the irradiation when the gender of patients was considered. Fresh blood specimens were obtained from volunteers using vacutainer tubes containing EDTA, at the Dr. Eliel Figueiredo Laboratory, Rio de Janeiro. All the samples were lyophilized for 48 hours in a freeze drier in order to remove the water. The scattering measurements were carried out in e-2e reflection geometry using a powder diffractometer Shimadzu XRD- 6000. The measured characterization parameters for LAXS were associated with epidemiological data (gender). The mean values of the different parameters were compared using the Students's t-test for each characterization parameters. The scattering profiles from plasma and formed elements are characterized by the presence of two peaks in the forward direction of scattering. For epidemiological data (gender) analyzed was not found significant changes in the mostly of characterization parameters (p>0.05). (author)

  12. Study of human blood and hemocomponents irradiated by low angle x ray scattering (LAXS)

    International Nuclear Information System (INIS)

    Pinto, Nivia G. Villela; Barroso, Regina C.; Mota, Carla L.S.; Almeida, Andre P.; Azeredo, Soraia R.; Braz, Delson

    2009-01-01

    Irradiation of blood and blood components is currently practiced in developed and in a few developing countries. The main purpose of this process is the prevention of graft versus host disease in immunodeficient patients. The Food and Drug Administration recommends a dose range of 15 Gy to 25 Gy for these blood components. When x-ray photons are scattered from biological samples, their angular distribution shows one or more peaks in the forward direction of scattering. These peaks are characteristic for the investigated samples. Due to its wide range of biological and medical applications, low-angle x-ray scattering has attracted the attention of many authors. Thus in this present work was studied the possible variations in scattering profiles due to the irradiation when the gender of patients was considered. Fresh blood specimens were obtained from volunteers using vacutainer tubes containing EDTA, at the Dr. Eliel Figueiredo Laboratory, Rio de Janeiro. All the samples were lyophilized for 48 hours in a freeze drier in order to remove the water. The scattering measurements were carried out in e-2e reflection geometry using a powder diffractometer Shimadzu XRD- 6000. The measured characterization parameters for LAXS were associated with epidemiological data (gender). The mean values of the different parameters were compared using the Students's t-test for each characterization parameters. The scattering profiles from plasma and formed elements are characterized by the presence of two peaks in the forward direction of scattering. For epidemiological data (gender) analyzed was not found significant changes in the mostly of characterization parameters (p>0.05). (author)

  13. 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)

  14. 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

  15. 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.

  16. 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

  17. 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.

  18. 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).

  19. Angular dependence of optical fibre thermoluminescent dosimeters irradiated using kilo- and megavoltage X-rays

    International Nuclear Information System (INIS)

    Moradi, F.; Ung, N.M.; Mahdiraji, G.A.; Khandaker, M.U.; Entezam, A.; See, M.H.; Taib, N.A.; Amin, Y.M.; Bradley, D.A.

    2017-01-01

    Prior investigation of the suitability of optical fibres as thermoluminescent dosimeters for diagnostic and therapeutic radiation beams has not included detailed study of the effect of beam angulation. Present study of such response has made use of optical fibre of cylindrical shape, exposed to 30 kVp photons from an X-ray tube and a 6 MV photon beam from a linear accelerator. The effect of the irradiation medium was also studied, comparing response free-in-air against on-surface and in-depth irradiations through use of solid-water™ phantom. Standard optical fibre (ø =125 µm) shows non-uniform response to beams delivered at different incident angles. Monte Carlo simulation provided support for the experimental results, also obtaining absorbed dose in the fibres. The results of free-in-air condition simulated with mono-energy beam show angle-independent response for photons within the energy range 100–500 keV, while dependency has been observed for beam energies of <100 keV and >500 keV. Experimentally, the angular dependency up to 35% is observed in 30 kVp free-in-air, while in 6 MeV beam, this is reduced to 20%, 10%, and 3% in free-in-air, on phantom surface, and in-depth conditions, respectively. The observations have been justified by considering the range of secondary electrons in the dosimeter and the effect of scattered radiation. - Highlights: • Irradiated free-in-air standard optical fibre dosimeters show significant angular dependence. • The dependency varies for photon energies obtained at kVp and MV potentials. • The irradiation medium influences the angular dependence. • With MeV beam irradiations under CPE conditions the angular dependence decreases to 3%.

  20. Pathogens Inactivated by Low-Energy-Electron Irradiation Maintain Antigenic Properties and Induce Protective Immune Responses

    Science.gov (United States)

    Fertey, Jasmin; Bayer, Lea; Grunwald, Thomas; Pohl, Alexandra; Beckmann, Jana; Gotzmann, Gaby; Casado, Javier Portillo; Schönfelder, Jessy; Rögner, Frank-Holm; Wetzel, Christiane; Thoma, Martin; Bailer, Susanne M.; Hiller, Ekkehard; Rupp, Steffen; Ulbert, Sebastian

    2016-01-01

    Inactivated vaccines are commonly produced by incubating pathogens with chemicals such as formaldehyde or β-propiolactone. This is a time-consuming process, the inactivation efficiency displays high variability and extensive downstream procedures are often required. Moreover, application of chemicals alters the antigenic components of the viruses or bacteria, resulting in reduced antibody specificity and therefore stimulation of a less effective immune response. An alternative method for inactivation of pathogens is ionizing radiation. It acts very fast and predominantly damages nucleic acids, conserving most of the antigenic structures. However, currently used irradiation technologies (mostly gamma-rays and high energy electrons) require large and complex shielding constructions to protect the environment from radioactivity or X-rays generated during the process. This excludes them from direct integration into biological production facilities. Here, low-energy electron irradiation (LEEI) is presented as an alternative inactivation method for pathogens in liquid solutions. LEEI can be used in normal laboratories, including good manufacturing practice (GMP)- or high biosafety level (BSL)-environments, as only minor shielding is necessary. We show that LEEI efficiently inactivates different viruses (influenza A (H3N8), porcine reproductive and respiratory syndrome virus (PRRSV), equine herpesvirus 1 (EHV-1)) and bacteria (Escherichia coli) and maintains their antigenicity. Moreover, LEEI-inactivated influenza A viruses elicit protective immune responses in animals, as analyzed by virus neutralization assays and viral load determination upon challenge. These results have implications for novel ways of developing and manufacturing inactivated vaccines with improved efficacy. PMID:27886076

  1. Thermoluminescence study of X-ray irradiated muscovite mineral under various heating rate

    International Nuclear Information System (INIS)

    Kalita, J.M.; Wary, G.

    2014-01-01

    The thermoluminescence (TL) glow curves of X-ray irradiated micro-grain natural muscovite were recorded within 298–520 K at various linear heating rates (2 K/s, 4 K/s, 6 K/s, 8 K/s and 10 K/s). Natural TL of muscovite was checked, but no significant TL was observed within 298–520 K in any heating rate. Within the heating rate 2–10 K/s only a low temperature distinct peak was observed in the temperature range 348–357 K. The TL parameters such as activation energy, order of kinetic, geometrical symmetry factor and pre-exponential frequency factor were investigated from the glow peak by Peak Shape (PS) method and Computerized Glow Curve Deconvolution (CGCD) technique. At lowest heating rate the glow peak obeys non-first order kinetic and at the highest heating rate it follows the second order kinetic. The variation of peak integrals, peak maximum temperatures, FWHM and activation energy with heating rates were investigated, and the glow curves at higher rates were found to be influenced by the presence of the thermal quenching. The thermal quenching activation energy and pre-exponential factor were calculated and found to be 2.31±0.02 eV and 3.46×10 14 s −1 , respectively. -- Highlights: • Muscovite is a silicate mineral with chemical formula KAl 2 (Si 3 Al)O 10 (OH,F) 2 . • TL of natural and X-ray induced muscovite was studied under various heating rates. • TL parameters were evaluated by Peak Shape and CGCD method. • Thermal quenching parameters (W and C) of muscovite were evaluated

  2. 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

  3. Study of the conductivity induced by radiation in teflon irradiated by X-ray

    International Nuclear Information System (INIS)

    Faria, R.M.

    1980-01-01

    It's measured the X-ray induced currents in teflon FEP which show the following features: a) At the beginning the current increases and reaches a maximum at about 10s, b) It decays slowly during 30 minutes, when a steady state is reached the delayed conductivity was also measured. The sample were 25 μm thick and the irradiated area was 12,5 cm 2 ; the applied field was of the order of 10 4 V/cm and the dose rate of order of 10 2 R/S. It was observed that a new measurement of the induced conductivity does not duplicate the first one, but after a few hours it comes back to the original one. In order to show that the increase and the decrease of the current is not caused by an electric field effect we realized a measurement where we polled the sample intermitently while it was irradiated. The current thus obtained had about the same values of the first measurement, when the voltage was applied all the time during the measurement. The absorption current of a teflon sample which shows after some days the effect of its variation due the variation of the ambiental temperature are measured. (Author) [pt

  4. Response of the skin of hamsters to fractionated irradiation with X rays or accelerated carbon ions

    International Nuclear Information System (INIS)

    Leith, J.T.; Powers-Risius, P.; Woodruff, K.H.; McDonald, M.; Howard, J.

    1981-01-01

    The ventral thoracic skin of hamsters was irradiated with either single, split (two fractions given in 24 hr), or multiple (five fractions given daily) exposures of X rays or accelerated carbon ions using a 4-cm spread Bragg peak. Animals were positioned in the heavy-ion beam so that the ventral thoracic skin surface was 1 cm distal to the proximal peak of the modified beam. Early skin reactions from 6 to 30 days postirradiation were assessed. Using the average skin reactions produced in this period, it was found that the relative biological effect (RBE) for single doses of carbon ions was about 1.6 (5-17 Gy per fraction), for two fractions about 1.8 (5-17 Gy perfraction), and for five fractions about 1.9 (2.4-7.2 Gy per fraction). The fractional amount of sublethal damage repaired after carbon ion irradiation was about 0.3 (at dose levels of 2.4-8.0 Gy per fraction) compared to a value of about 0.45 (at dose levels of 60-13.0 Gy per fraction) found for the fractionated X irradiations, indicting about a 33% decrease in the relative amount of sublethal damage repaired after carbon ion irradiation in this position in the spread Bragg curve. Also, data were interpreted using plots of the reciprocal total dose needed to produce a given level of skin damage versus the dose per fraction used in the multifraction experiments, and of the RBE versus dose per fraction obtained from a nonparametric analysis of the responses. These approaches allow estimation of RBE at dose levels relevant to the clinical situation. Also, estimation may be made of the maximum permissible RBE by using the zero dose intercept value from the linear reciprocal dose plot. With this approach, the RBE at a dose level of 2 Gy is about 2.5 and the maximum RBE value is about 2.7

  5. Irradiation of intense characteristic x-rays from weakly ionized linear molybdenum plasma

    International Nuclear Information System (INIS)

    Sato, Eiichi; Hayasi, Yasuomi

    2003-01-01

    In the plasma flash x-ray generator, a high-voltage main condenser of approximately 200 nF is charged up to 55 kV by a power supply, and electric charges in the condenser are discharged to an x-ray tube after triggering the cathode electrode. The flash x-rays are then produced. The x-ray tube is a demountable triode that is connected to a turbo molecular pump with a pressure of approximately 1 mPa. As electron flows from the cathode electrode are roughly converged to a rod molybdenum target of 2.0 mm in diameter by the electric field in the x-ray tube, weakly ionized linear plasma, which consists of molybdenum ions and electrons, forms by target evaporation. At a charging voltage of 55 kV, the maximum tube voltage was almost equal to the charging voltage of the main condenser, and the peak current was about 20 kA. When the charging voltage was increased, the linear plasma formed, and the K-series characteristic x-ray intensities increased. The K lines were quite sharp and intense, and hardly any bremsstrahlung rays were detected. The x-ray pulse widths were approximately 700 ns, and the time-integrated x-ray intensity had a value of approximately 35 μC/kg at 1.0 m from the x-ray source with a charging voltage of 50 kV. (author)

  6. 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.

  7. Time-resolved x-ray line emission studies of thermal transport in multiple beam uv-irradiated targets

    International Nuclear Information System (INIS)

    Jaanimagi, P.A.; Henke, B.L.; Delettrez, J.; Richardson, M.C.

    1984-01-01

    Thermal transport in spherical targets irradiated with multiple, nanosecond duration laser beams, has been a topic of much discussion recently. Different inferences on the level of thermal flux inhibition have been drawn from plasma velocity and x-ray spectroscopic diagnostics. We present new measurements of thermal transport on spherical targets made through time-resolved x-ray spectroscopic measurements of the progress of the ablation surface through thin layers of material on the surface of the target. These measurements, made with 6 and 12 uv (351 nm) nanosecond beams from OMEGA, will be compared to previous thermal transport measurements. Transparencies of the conference presentation are given

  8. 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

  9. 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

  10. 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.

  11. X-ray irradiation induced reduction and nanoclustering of lead in borosilicate glass

    NARCIS (Netherlands)

    Stanley, H.B.; Banerjee, D.; Breemen, van L.C.A.; Ciston, J.; Liebscher, C.H.; Martis, V.; Merino, D.H.; Longo, A.; Pattison, P.; Peters, G.W.M.; Portale, G.; Sen, Sabyasachi; Bras, W.

    2014-01-01

    We have studied the formation of nanoparticles in lead sulfide (PbS)-doped borosilicate glass subjected to a two-step nucleation and growth heat treatment using in situ small-angle X-ray scattering (SAXS). The microstructure produced was subsequently characterized using X-ray powder diffraction

  12. 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

  13. Argon defect complexes in low energy Ar irradiated molybdenum

    International Nuclear Information System (INIS)

    Veen, A. van; Buters, W.T.M.; Kolk, G.J. van der; Caspers, L.M.; Armstrong, T.R.

    1982-01-01

    Thermal desorption spectrometry has been used to study the defects created in Mo irradiated along the direction with Ar ions ranging in energy from 0.1 to 2 keV. In addition to monitoring the release of the implanted Ar, additional information has been obtained by decoration of the defects with low energy helium and subsequent monitoring of the helium release. The studies show evidence that the Ar can be trapped in both substitutional sites and in a configuration in which the Ar is associated with vacancies (ArVsub(n), n >= 2). Most of the Ar implanted at high energy is released at approx. equal to 1500 K by thermal vacancy assisted diffusion. Argon trapped closer to the surface is released at lower temperatures via at least three different surface related release mechanisms. Additional results are presented on the interaction of self interstitial atoms (introduced by 100 eV Xe bombardment) with the Ar defects. Substitutional Ar is found to convert to interstitial Ar which seems to be mobile at room temperature. The Ar-vacancy complexes are found to be reduced to substitutional Ar. The results of atomistic calculations of the release mechanisms will also be presented. (orig.)

  14. 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)

  15. 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.

  16. Bright x-ray sources from laser irradiation of foams with high concentration of Ti

    Energy Technology Data Exchange (ETDEWEB)

    Pérez, F., E-mail: perez75@llnl.gov; Patterson, J. R.; May, M.; Colvin, J. D.; Biener, M. M.; Wittstock, A.; Kucheyev, S. O.; Charnvanichborikarn, S.; Satcher, J. H.; Gammon, S. A.; Poco, J. F.; Fournier, K. B. [Lawrence Livermore National Laboratory, 7000 East Ave., Livermore, California 94550 (United States); Fujioka, S.; Zhang, Z.; Ishihara, K.; Tanaka, N.; Ikenouchi, T.; Nishimura, H. [Institute of Laser Engineering, Osaka University, 2-6 Yamada-Oka, Suita, Osaka 565-0871 (Japan)

    2014-02-15

    Low-density foams irradiated by a 20 kJ laser at the Omega laser facility (Laboratory for Laser Energetics, Rochester, NY, USA) are shown to convert more than 5% of the laser energy into 4.6 to 6.0 keV x rays. This record efficiency with foam targets is due to novel fabrication techniques based on atomic-layer-deposition of Ti atoms on an aerogel scaffold. A Ti concentration of 33 at. % was obtained in a foam with a total density of 5 mg/cm{sup 3}. The dynamics of the ionization front through these foams were investigated at the 1 kJ laser of the Gekko XII facility (Institute for Laser Engineering, Osaka, Japan). Hydrodynamic simulations can reproduce the average electron temperature but fail to predict accurately the heat front velocity in the foam. This discrepancy is shown to be unrelated to the possible water adsorbed in the foam but could be attributed to effects of the foam micro-structure.

  17. X-ray diffraction pattern and relative crystallinity of irradiated arrowroot starch

    Energy Technology Data Exchange (ETDEWEB)

    Barroso, Aline G.; Garcia, Rafael H.L.; Del Mastro, Nelida L., E-mail: nlmastro@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2017-11-01

    After cereals, tubers and roots are the major source of starch for food and industrial uses. Arrowroot refers to any plant of the genus Marantha, but the term is most commonly used to describe the easily digested starch obtained from the rhizomes of Marantha arundinacae. The rhizomes of this herbaceous plant contain about 20% of starch. As few studies exist on arrowroot starch, the objective of this preliminary work was to study the X-ray diffraction patterns (XRD) patterns of arrowroot starch when treated by γ-radiation with doses up to 15 kGy in a {sup 60}Co source. The XRD patterns of the arrowroot starch exhibited A-type crystalline arrangements with strong peaks at approximately 15º, 17º, 18º and 23º (2θ). A slight increase of diffractogram peaks intensity was noticed after the irradiation process. The crystallinity index was calculated using Bruker DIFFRAC.EVA version 4.2 software. Relative crystallinity seems to increase with radiation doses, and this effect is more noticeable at low doses. That can be attributed to different radiation sensitivity among the amorphous and crystalline regions of the arrowroot starch molecule. Present results will contribute to elucidate the behavior under radiation treatment of this starchy component increasingly employed by the food industry. (author)

  18. Dysplasia of the temporo-maxillary joint of mouse embryos due to x-ray irradiation

    International Nuclear Information System (INIS)

    Shibata, Shigeo

    1974-01-01

    On the 9-13 pregnant days of ddN mice 200-300 R of X-ray was daily irradiated, and observations were made on the formation of micro-mandible and changes in the temporo-maxillary joint in the embryos on the 18th pregnant day using skeletal and H-E stain specimens. Gross observation revealed the emergence of observable micro-mandible in groups exposed to 200 R on the 10th and 11th pregnant days and in groups exposed to 300 R on the 11th and 12th pregnant days. By skeletal specimens also, micro-mandible was observed in groups exposed on and after the 10th pregnant day, and anomaly of the malar arch was frequently associated with anomaly of the mandibular branches and growth inhibition of the anterior region of the mandible. Histologically, there were observed embryos totally lacking the temporo-maxillary joint composing elements, resulting in fusion with the temporal bone, or embryos lacking the elements partially or complicated by anomaly of cartilagious tissue of the mandibular head. (Mukohata, S.)

  19. Experience with Exacin ointment for erosive dermatitis arising after X-ray and electron irradiation

    International Nuclear Information System (INIS)

    Suzuki, Yoshihiko

    1995-01-01

    An ointment containing Exacin (isepamicin sulfate) was used to prevent infection in 12 female patients with erosive (acute) or chronic dermatitis caused by X-ray and electron irradiation. Underlying diseases were skin metastasis from breast cancer (n=3), advanced cervical cancer (n=3), positive margin of cervical cancer (n=2), vaginal cancer (n=2), recurrence of rectal cancer (n=one), and vulvar cancer (n=one). Exacin ointment (a daily dose of approximately 6 g) was applied in two or more divided doses to lesions in the vulva (n=9), axillary chest wall (n=one), and chest wall (n=2) for 16-65 days in the group of erosive radiodermatitis (n=10) and for 3-10 months in the group of chronic radiodermatitis (n=2). In the group of erosive radiodermatitis, 8 were evaluated as remarkably improved; in the group of chronic radiodermatitis, one was evaluated as slightly improved and one as unchanged. Exacin ointment was considered to be effective for erosive dermatitis to prevent infection. (N.K.)

  20. X-ray diffraction pattern and relative crystallinity of irradiated arrowroot starch

    International Nuclear Information System (INIS)

    Barroso, Aline G.; Garcia, Rafael H.L.; Del Mastro, Nelida L.

    2017-01-01

    After cereals, tubers and roots are the major source of starch for food and industrial uses. Arrowroot refers to any plant of the genus Marantha, but the term is most commonly used to describe the easily digested starch obtained from the rhizomes of Marantha arundinacae. The rhizomes of this herbaceous plant contain about 20% of starch. As few studies exist on arrowroot starch, the objective of this preliminary work was to study the X-ray diffraction patterns (XRD) patterns of arrowroot starch when treated by γ-radiation with doses up to 15 kGy in a "6"0Co source. The XRD patterns of the arrowroot starch exhibited A-type crystalline arrangements with strong peaks at approximately 15º, 17º, 18º and 23º (2θ). A slight increase of diffractogram peaks intensity was noticed after the irradiation process. The crystallinity index was calculated using Bruker DIFFRAC.EVA version 4.2 software. Relative crystallinity seems to increase with radiation doses, and this effect is more noticeable at low doses. That can be attributed to different radiation sensitivity among the amorphous and crystalline regions of the arrowroot starch molecule. Present results will contribute to elucidate the behavior under radiation treatment of this starchy component increasingly employed by the food industry. (author)

  1. Microbicidal effectiveness of X-rays used for sterilization purposes

    DEFF Research Database (Denmark)

    Tallentire, Alan; Miller, Arne

    2015-01-01

    The radiation response of spores of Bacillus pumilus was examined for irradiation with 5–7 MeV X-ray at commercial sterilization facilities. The response was found to be the same as that for irradiation with cobalt 60 photons, 10 MeV electrons and low energy electrons at 100 and 80 keV....

  2. 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

  3. 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

  4. 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

  5. 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)

  6. Anatomical alterations of Phaseolus vulgaris L. mature leaves irradiated with X-rays.

    Science.gov (United States)

    De Micco, V; Arena, C; Aronne, G

    2014-01-01

    The cultivation of higher plants in Space involves not only the development of new agro-technologies for the design of ecologically closed Space greenhouses, but also understanding of the effects of Space factors on biological systems. Among Space factors, ionising radiation is one of the main constraints to the growth of organisms. In this paper, we analyse the effect of low-LET radiation on leaf histology and cytology in Phaseolus vulgaris L. plants subjected to increasing doses of X-rays (0.3, 10, 50, 100 Gy). Leaves irradiated at tissue maturity were compared with not-irradiated controls. Semi-thin sections of leaves were analysed through light and epi-fluorescence microscopy. Digital image analysis was applied to quantify anatomical parameters, with a specific focus on the occurrence of signs of structural damage as well as alterations at subcellular level, such as the accumulation of phenolic compounds and chloroplast size. Results showed that even at high levels of radiation, general anatomical structure was not severely perturbed. Slight changes in mesophyll density and cell enlargement were detected at the highest level of radiation. However, at 100 Gy, higher levels of phenolic compounds accumulated along chloroplast membranes: this accompanied an increase in number of chloroplasts. The reduced content of chlorophylls at high levels of radiation was associated with reduced size of the chloroplasts. All data are discussed in terms of the possible role of cellular modifications in the maintenance of high radioresistance and photosynthetic efficiency. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.

  7. Non-destructive assessment of the polarity of GaN nanowire ensembles using low-energy electron diffraction and x-ray photoelectron diffraction

    Czech Academy of Sciences Publication Activity Database

    Romanyuk, Olexandr; Fernández-Garrido, S.; Jiříček, Petr; Bartoš, Igor; Geelhaar, L.; Brandt, O.; Paskova, T.

    2015-01-01

    Roč. 106, č. 2 (2015), "021602-1"-"021602-4" ISSN 0003-6951 Grant - others:AVČR(CZ) M100101201 Institutional support: RVO:68378271 Keywords : GaN nanowires * X-ray photoelectron diffraction * LEED I-V * GaN polarity Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.142, year: 2015

  8. 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)

  9. Studies of Bystander Effect and Intercellular Communication in Human Epithelial Cell Cultures Irradiated with X-rays

    International Nuclear Information System (INIS)

    Romppanen, E.; Trott, K. R.; Musatonen, R.; Leszcznski, D.; Belyakov, O.

    2004-01-01

    The bystander effect is a phenomenon whereby biological consequences of irradiation are expressed in nonexposed cells in the vicinity of exposed cells. Two main pathways have been proposed to mediate the bystander effect: Gap Junction Intercellular Communication (GJIC) and medium borne soluble factors dependent mechanisms. The present study was designed to evaluate the relative contributions of gap junction intercellular communication and of soluble extracellular factors on the bystander effects of low dose X-ray irradiation. HaCaT human epithelial cell monolayers were exposed to X-ray using specially constructed shield, which cover 95% or 56% or 0% of the cells from the radiation. To evaluate whether the GJIC is involved in transmission of the bystander signal from irradiated to nonirradiated cells, irradiations were performed in presence or absence of GJIC inhibitor lindane. The cytochalasin B block technique was used to quantify fractions of micronucleated cells 48 hours after the irradiation. Our results suggest that more micronucleated cells are induced in partially shielded monolayers than expected according to back extrapolation of the data from open field irradiation. Treatment with lindane considerably reduced amount of the bystander damage. We demonstrated that fraction of micronucleated cells after X-rays irradiation of 5% of cells with 1 Gy was 0.07±0.08 (without lindane) and 0.05±0.004 (in presence of lindane). Irradiation of 100% of cells with the same dose resulted in 0.023±0.04 /without lindane) and 0.013±0.02 (in presence of lindane) fractions of micronucleated cells. Comparison with open field data showed that the fraction of micronucleated cells after irradiation of 5% of the cell culture was 5-10 times greater than the estimated fraction assuming no bystander effect. Irradiation of 44% of cells ded not demonstrate a pronounced bystander effect. (Author) 20 refs

  10. 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.

  11. 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

  12. 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.

  13. Silicon passivation study under low energy electron irradiation conditions

    International Nuclear Information System (INIS)

    Cluzel, R.

    2010-01-01

    Backside illuminated thinned CMOS (Complementary Metal Oxide Semiconductor) imaging system is a technology developed to increase the signal to noise ratio and the sensibility of such sensors. This configuration is adapted to the electrons detection from the energy range of [1 - 12 keV]. The impinging electron creates by multiplication several hundreds of secondary electrons close to the surface. A P ++ highly-doped passivation layer of the rear face is required to reduce the secondary electron surface recombination rate. Thanks to the potential barrier induced by the P ++ layer, the passivation layer increases the collected charges number and so the sensor collection gain. The goal of this study is to develop some experimental methods in order to determine the effect of six different passivation processes on the collection gain. Beforehand, the energy profile deposited by an incident electron is studied with the combination of Monte-Carlo simulations and some analytical calculations. The final collection gain model shows that the mirror effect from the passivation layer is a key factor at high energies whereas the passivation layer has to be as thin as possible at low energies. A first experimental setup which consists in irradiating P ++ /N large diodes allows to study the passivation process impacts on the surface recombinations. Thanks to a second setup based on a single event upset directly on thinned CMOS sensor, passivation techniques are discriminated in term of mirror effect and the implied spreading charges. The doping atoms activation laser annealing is turn out to be a multiplication gain inhomogeneity source impacting directly the matrix uniformity. (author)

  14. Mortality and sterility induced in Piophila casei by x-ray and neutron irradiation

    International Nuclear Information System (INIS)

    Sacchi, L.; Gasperi, G.; Grigolo, A.; Caprotti, M.; Pinelli, T.; Altieri, S.

    1977-01-01

    Different doses of neutrons and X-rays were given to 5-day-old pupae of Piophila casei L. (Diptera, Piophilidae), just before their emergence. The mortality and sterility induced by the different types of radiation were measured. Neutrons are more effective than X-rays in provoking lethal lesions in somatic cells. Females are more resistant than males to the sterilizing action of neutrons, the relative biological efficiency of neutrons being 6 and 3.5, respectively

  15. Mortality and sterility induced in Piophila casei by x-ray and neutron irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Sacchi, L; Gasperi, G [Pavia Univ. (Italy). Ist. di Zoologia; Grigolo, A [Bari Univ. (Italy). Ist. di Zoologia e Anatomia Comparata; Caprotti, M [Pavia Univ. (Italy). Fondazio Clinica del Lavoro. Reparto di Radiologia; Pinelli, T; Altieri, S [Pavia Univ. (Italy). Istituto di Fisica Nucleare

    1977-01-01

    Different doses of neutrons and X-rays were given to 5-day-old pupae of Piophila casei L. (Diptera, Piophilidae), just before their emergence. The mortality and sterility induced by the different types of radiation were measured. Neutrons are more effective than X-rays in provoking lethal lesions in somatic cells. Females are more resistant than males to the sterilizing action of neutrons, the relative biological efficiency of neutrons being 6 and 3.5, respectively.

  16. 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.)

  17. 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

  18. 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.)

  19. X-RAY IRRADIATION OF THE LkCa 15 PROTOPLANETARY DISK

    Energy Technology Data Exchange (ETDEWEB)

    Skinner, Stephen L. [CASA, University of Colorado, Boulder, CO 80309-0389 (United States); Guedel, Manuel, E-mail: stephen.skinner@colorado.edu, E-mail: manuel.guedel@univie.ac.at [Department of Astronomy, University of Vienna, Tuerkenschanzstr. 17, A-1180 Vienna (Austria)

    2013-03-01

    LkCa 15 in the Taurus star-forming region has recently gained attention as the first accreting T Tauri star likely to host a young protoplanet. High spatial resolution infrared observations have detected the suspected protoplanet within a dust-depleted inner gap of the LkCa 15 transition disk at a distance of {approx}15 AU from the star. If this object's status as a protoplanet is confirmed, then LkCa 15 will serve as a unique laboratory for constraining physical conditions within a planet-forming disk. Previous models of the LkCa 15 disk have accounted for disk heating by the stellar photosphere but have ignored the potential importance of X-ray ionization and heating. We report here the detection of LkCa 15 as a bright X-ray source with Chandra. The X-ray emission is characterized by a cool, heavily absorbed plasma component at kT {sub cool} Almost-Equal-To 0.3 keV and a harder component at kT {sub hot} Almost-Equal-To 5 keV. We use the observed X-ray properties to provide initial estimates of the X-ray ionization and heating rates within the tenuous inner disk. These estimates and the observed X-ray properties of LkCa 15 can be used as a starting point for developing more realistic disk models of this benchmark system.

  20. L-shell x-ray yields and production cross-sections of molybdenum induced by low-energy highly charged argon ions

    International Nuclear Information System (INIS)

    Du Juan; Xu Jinzhang; Chen Ximeng; Yang Zhihu; Shao Jianxiong; Cui Ying; Zhang Hongqiang; Gao Zhimin; Liu Yuwen

    2007-01-01

    L-shell x-ray yields of molybdenum bombarded by highly charged Ar q+ ions (q=11-16) are measured. The x-ray production cross-sections are extracted from the yields data. The energy of the incident Ar ions ranges from 200 to 350 keV. After the binding energy correction, experimental data are explained in the framework of binary-encounter-approximation (BEA). The direct ionization is treated in the united atom (UA) limit (Lapicki and Lichten 1985 Phys. Rev. A 31 1354), not in the separate atom (SA) limit. The calculation results of BEA (Gacia and Fortner 1973 Rev. Mod. Phys. 45 111) are much lower than the experimental results, while the results of binding energy modified BEA are basically in agreement with the experimental results

  1. Measurements of L-shell x-ray production cross-sections of Au and Ag by low energy electron impact

    International Nuclear Information System (INIS)

    Wu, Y; An, Z; Liu, M T; Duan, Y M; Tang, C H; Luo, Z M

    2004-01-01

    Au L α and L β and Ag L-shell x-ray production cross-sections by electron impact have been measured in the incident energy region from near threshold to about 25 keV. Thin films with thick aluminium substrates were used as targets in the experiments. The effect of directional and energy spreading of the electron beam within the active films and x-ray enhancement due to backscattering electrons and bremsstrahlung photons from the substrates are corrected by means of Monte Carlo simulations. The corrected experimental data provided by this method are compared with calculated cross-sections from a PWBA theory with Coulomb, relativistic and exchange corrections and with other experimental data available in the literature

  2. 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)

  3. Structure of X-ray photoelectron spectra of low-energy and core electrons of Ln(C6H4OCH3COO-3

    Directory of Open Access Journals (Sweden)

    Teterin Yury A.

    2005-01-01

    Full Text Available This paper deals with the results of an X-ray photo electron spectroscopy of lanthanide ortho-metoxybenzoates Ln(C6H4OCH3COO-3, where Ln represents lanthanides La through Lu except for Pm and C6H4OCH3COO- - residuum of ortho-metoxybenzoic acid. The core and outer electron X-ray photo electron spectroscopy spectra in the binding energy range of 0-1250 eV were shown to exhibit a complex, fine structure. The said structure was established due to the outer (0-15 eV binding energy and inner (15-50 eV binding energy valence molecular orbital from the filled Ln5p and O2s atomic shells multiple splitting, many-body perturbation, dynamic effect, etc. The mechanisms of such a fine structure formation were shown to manifest different probabilities in the spectrum of a certain electronic shell. There fore, the fine X-ray photo electron spectroscopy spectral structure resulting from a certain mechanism can be interpreted and its quantitative parameters related to the physical and chemical properties of the studied com pounds (degree of delocalization and participation of Ln4f electrons in the chemical bond, electronic configuration and oxidation states, density of uncoupled electrons on paramagnetic ions, degree of participation of the low binding energy filled electronic shells of lanthanide and ligands information of the outer and in nervalence molecular orbitals, lanthanide close environment structure in amorphous materials, etc.

  4. Response of TLD-100 LiF dosimeters for X-rays of low energies; Respuesta de dosimetros de TLD-100 de LiF para rayos X de bajas energias

    Energy Technology Data Exchange (ETDEWEB)

    Bonzi, E. V.; Mainardi, R. T. [Universidad Nacional de Cordoba, Facultad de Matematica, Astronomia y Fisica, Av. Haya de la Torre y Av. Medina Allende s/n, Ciudad Universitaria, X5016LEA Cordoba (Argentina)

    2011-10-15

    In diverse practical applications as the existent in radiological clinics, industrial facilities and research laboratories, the solid state dosimeters are used for the measure of the different types of ionizing radiations. At the present time dosimeters are manufactured with different types of materials that present thermoluminescent properties, to the effects of determining the absorbed radiation dose. Under these conditions, the radiation dose is determined integrated in all the range of energies of the beam of X-rays, since it assumes that the response of these dosimeters is lineal with the energy of the photons or radiant particles. Because interest exists in advancing in the development of a determination method in the way of the X-rays spectrum emitted by a tube of those used in diagnostic or therapy, we have measured the response of TLD-100 LiF dosimeters for low energies, minor at 60 keV, for a several group of these dosimeters. (Author)

  5. 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.

  6. 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)

  7. 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

  8. 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

  9. Determination of dose enhancement caused by gold-nanoparticles irradiated with proton, X-rays (kV and MV) and electron beams, using alanine/EPR dosimeters

    International Nuclear Information System (INIS)

    Smith, Clare L.; Ackerly, Trevor; Best, Stephen P.; Gagliardi, Frank; Kie, Katahira; Little, Peter J.; McCorkell, Giulia; Sale, Charlotte A.; Tsunei, Yusuke; Tominaga, Takahiro; Volaric, Sioe See; Geso, Moshi

    2015-01-01

    The main aims of this research was to employ alanine doped with gold-nanoparticles “AuNPs” to determine the levels of dose enhancement caused by these particles when irradiated with proton beams, low and high energy X-rays and electrons. DL-alanine was impregnated with 5 nm gold-nanoparticles (3% by weight) and added as a uniform layer within a wax pellet of dimensions 10 × 5 × 5 mm. Control pellets, containing DL-Alanine were also produced, and placed within a phantom, and exposed to various types of radiations: low energy (kV ranges) X-rays were obtained from a superficial machine, high energy (MV) X-rays and electrons derived from a linear accelerator, and protons were produced by the Hyogo Ion Beam Centre in Japan. Nominal doses received ranged from 2 to 20 Gy (within clinical range). The Electron Paramagnetic Resonance (EPR) spectra of the irradiated samples were recorded on a BRUKER Elexsys 9.5 MHz. The dose enhancement caused by gold nanoparticles for 80 kV x-rays was found to be more than 60% at about 5 Gy. Smaller dose enhancements (under the same measurement conditions) were observed for megavoltage x-ray beams (up to 10%). Dose enhancement caused by charged particles indicated minimal values for 6 MeV electrons (approximately 5%) whilst less than that is obtained with protons of 150 MeV. The proton results validate the latest simulation results based on Monte Carlo calculations but the dose enhancement is significantly less than that reported in cell and animal model systems, (about 20%). We attribute this difference to the fact that alanine only measures the levels of free radicals generated by the inclusion of nanoparticles and not the redox type radicals (such as reactive oxygen species) generated from aqueous media in cells. Dose enhancement caused by 5 nm gold-nanoparticles with radiotherapy type proton beams has been found to be less than 5% as determined when using alanine/wax as both a phantom and dosimeter. This agrees well

  10. Analysis of the procedures and criteria for implantation of X-ray beams for ISO 4037 reference at low energies; Analise dos procedimentos e criterios de implantacao de feixes de raios X de referencia ISO 4037 em baixas energias

    Energy Technology Data Exchange (ETDEWEB)

    Figueiredo, Marcus Tadeu Tanuri de

    2012-07-01

    According to the radiological protection principles, practices involving ionizing radiation must be planned and carried out under the guarantee that the values of individual doses, the number of people exposed to radiation and the probability of accidental exposures are as low as reasonably achievable. Therefore, radiation dosimetry is required to be done with reliable instruments designed for measuring dosimetric quantities. The reliability of the dosimetry depends on both the calibration of the dosimeter and its proper performance under certain test conditions. The International Standardization Organization (ISO), in order to promote international standardization and metrological coherency, established sets of reference X-ray beams for dosimeter calibration and typing-test; they are expected to be implemented in metrology laboratories in compliance with specific technical requirements. At low energies there are specific requirements that need to be considered in both the implementation of the reference beams and their use in calibration and testing. The present study is an analysis of the procedures and criteria for ISO 4037 reference radiation implementation, at low energies. In the Dosimeter Calibration Laboratory of the Development Center of Nuclear Technology (LCD / CDTN), experiments were performed for determining the X-ray reference radiation parameters. Alternatives to the usual methods for half-value layer determination were studied. Spectra of reference beams were simulated with software and compared with experimental measurements. Different climatic conditions were reproduced in the Laboratory for analysis of its influence on the determination of the beam parameters. Uncertainties in the measurements of studied parameters were evaluated. According to the ISO 4037 criteria, the low energy X-ray beams were considered to be implemented; they allowed the determination of the conversion coefficients from air kerma to the operational radiation protection

  11. 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)

  12. 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.

  13. 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

  14. 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.

  15. 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)

  16. Determination of Fission Products in Irradiated Fuel by X-Ray Fluorescence

    DEFF Research Database (Denmark)

    Mogensen, Mogens Bjerg; Als-Nielsen, Jens Aage; Andersen, Niels Hessel

    X-ray fluorescence i s a well e s t a b l i s h e d analytical tool for measuring elemental composition of fairly large (~ 5 cm2) "cold" samples. A version of t h i s technique has been developed for a n a l y s i s of radial d i s t r i b u t i o n of f i s s i o n products Xe, Cs and Ba...... in the scanning d i rection and 2 mm long. The measured Xe Ko x-ray i n t e n s i t i e s are converted to absolute concentrations by comparing to the intens i t y from a Xe gas standard. In the case of Cs and Ba s o l id standards may be used. The X-ray fluorescence analysis i s compared to other techniques used...... to obtain radial f i s s i o n product profiles, i t i s shown how a combination of X-ray fluorescence and electron probe micro a n a l y s i s i s able to reveal the amount of Xe in the grain boundary porosities....

  17. 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

  18. Depth determination of low-energy photon emitter deposits in tissue by means of high-resolution X-ray spectrometry

    International Nuclear Information System (INIS)

    Schlueter, W.

    1982-01-01

    A method has been developed for ascertaining the depth of low-energy photon emitters deposited in wounds. It is based on the determination of the energy-dependent absorption of the emitted photons by the tissue separating source and detector. The method is applicable to counting for low-energy photon-emitting nuclides that can be characterized by more than one quantum energy. Attenuation coefficients were given for lard, beef, and five tissue- equivalent materials. For spectrometry, a planar Ge(Li) detector proved most suitable. (author)

  19. Velocity-Resolved [Ne III] from X-Ray Irradiated Sz 102 Microjets

    Science.gov (United States)

    Liu, C.-F.; Shang, H.; Walter, F. M.; Herczeg, G. J.

    2014-03-01

    Neon emission lines are good indicators of high-excitation regions close to a young stellar system because of their high ionization potentials and large critical densities. We have discovered [Ne III] .3869 emission from the microjet of low-mass young star Sz 102. Spectroastrometric analysis of the two-dimensional [Ne III] spectral image obtained from the archival high-dispersion (R - 33,000) Very Large Telescope/UVES spectra suggests that the emission consists of two velocity components spatially separated by ~ 0.''3. The stronger redshifted component is centered at ~ +21 km s-1 with a line width of ~ 140 km s-1, and the weaker blueshifted component at ~ -90 km s-1 with a larger line width of ~ 190 km s-1. Both components have large line widths that extend across the systemic velocity, suggesting their origin from diverging streamlines of a wide-angle wind. Optical line ratio diagnostics indicate that Sz 102 drives a pair of hot (T . 2 ◊ 104 K) and ionized (ne . 2 ◊ 104 cm-3) jets. The blueshifted jet has on average ~ 50% higher temperature and electron density. We suggest that the jet is ionized by an embedded hard X-ray source close to the driving region. Freezing-in of the ionization state is consistent with the flow speed and the Ne2+ recombination timescales. We postulate that these X-rays originate from hard coronae or stellar flares; the hard (keV) X-ray photons ionize neon in the inner wind, while the soft X-rays are mostly absorbed by the accretion funnel. These postulates await validation from high-sensitivity X-ray and subarcsecond resolution optical observations.

  20. Low-energy irradiation effects of gas cluster ion beams

    International Nuclear Information System (INIS)

    Houzumi, Shingo; Takeshima, Keigo; Mochiji, Kozo; Toyoda, Noriaki; Yamada, Isao

    2007-01-01

    A cluster-ion irradiation system with cluster-size selection has been developed to study the effects of the cluster size for surface processes using cluster ions. A permanent magnet with a magnetic field of 1.2 T is installed for size separation of large cluster ions. Trace formations at HOPG surface by the irradiation with size-selected Ar-cluster ions under acceleration energy of 30 keV were investigated by a scanning tunneling microscopy. Generation behavior of the crater-like traces is strongly affected by the number of constituent atoms (cluster size) of the irradiating cluster ion. When the incident cluster ion is composed of 100-3000 atoms, crater-like traces are observed on the irradiated surfaces. In contrast, such traces are not observed at all with the irradiation of the cluster-ions composed of over 5000 atoms. Such the behavior is discussed on the basis of the kinetic energy per constituent atom of the cluster ion. To study GCIB irradiation effects against macromolecule, GCIB was irradiated on DNA molecules absorbed on graphite surface. By the GCIB irradiation, much more DNA molecules was sputtered away as compared with the monomer-ion irradiation. (author)

  1. X-ray spectroscopy study of electronic structure of laser-irradiated Au nanoparticles in a silica film

    International Nuclear Information System (INIS)

    Jonnard, P.; Bercegol, H.; Lamaignere, L.; Morreeuw, J.-P.; Rullier, J.-L.; Cottancin, E.; Pellarin, M.

    2005-01-01

    The electronic structure of gold nanoparticles embedded in a silica film is studied, both before and after irradiation at 355 nm by a laser. The Au 5d occupied valence states are observed by x-ray emission spectroscopy. They show that before irradiation the gold atoms are in metallic states within the nanoparticles. After irradiation with a fluence of 0.5 J/cm 2 , it is found that gold valence states are close to those of a metal-poor gold silicide; thanks to a comparison of the experimental Au 5d states with the calculated ones for gold silicides using the density-functional theory. The formation of such a compound is driven by the diffusion of the gold atoms into the silica film upon the laser irradiation. At higher fluence, 1 J/cm 2 , we find a higher percentage of metallic gold that could be attributed to annealing in the silica matrix

  2. Production of humoral factors that stimulate spleen colony-forming units in mice irradiated with moderate doses of X rays

    International Nuclear Information System (INIS)

    Grande, T.; Gonzalez, J.; Tejero, C.; Maganto, G.; Bueren, J.A.

    1990-01-01

    The production of humoral factors that stimulate spleen colony-forming units (CFU-S) has been studied in irradiated mice using an in vivo diffusion chamber assay. The experiments show that a significant release of factors that stimulate CFU-S takes place in the first few days after irradiation with moderate doses of 1.5 or 5 Gy. In contrast, the release of significant amounts of these humoral factors was not seen in animals irradiated with either low (0.75 Gy) or high (10 Gy) doses of X rays. The correlation observed between the production of factors that stimulate the CFU-S and the hemopoietic regeneration kinetics of the irradiated mice suggests that these factors represent part of the physiological regulators controlling the proliferation of CFU-S

  3. Advanced light element and low energy X-ray line analysis using Energy Dispersive Spectrometry (EDS) with Silicon Drift Detectors (SDD)

    Science.gov (United States)

    Salge, T.; Palasse, L.; Berlin, J.; Hansen, B.; Terborg, R.; Falke, M.

    2013-12-01

    Introduction: Characterization at the micro- to nano-scale is crucial for understanding many processes in earth, planetary, material and biological sciences. The composition of thin electron transparent samples can be analyzed in the nm-range using transmission electron microscopes (TEM) or, specific sample holders provided, in the field emission scanning electron microscope (FE-SEM). Nevertheless both methods often require complex sample preparation. An alternative method is to analyze bulk samples with a FE-SEM. In order to decrease the excitation volume for generated X-rays, low accelerating voltages (HVNelson et al. 2012. GCA 86: 1-20. [5] Salge et al. 2013. LPI Contrib .No. 1737: 89. [6] M. Falke et al. 2013. EURO BioMat. 23-24.04.2013, Weimar, Germany. [7] H. Yurdakul et al. 2013.accepted for MC 2013, 25-30.08.2013, Regensburg, Germany [8] O. Tunckan 2010. PhD thesis. Anadolu University, Eskisehir, Turkey.

  4. Simulation results for PLATO: a prototype hybrid X-ray photon counting detector with a low energy threshold for fusion plasma diagnostics

    International Nuclear Information System (INIS)

    Habib, A.; Menouni, M.; Pangaud, P.; Morel, C.; Fenzi, C.; Colledani, G.; Moureau, G.; Escarguel, A.

    2017-01-01

    PLATO is a prototype hybrid X-ray photon counting detector that has been designed to meet the specifications for plasma diagnostics for the WEST tokamak platform (Tungsten (W) Environment in Steady-state Tokamak) in southern France, with potential perspectives for ITER. PLATO represents a customized solution that fulfills high sensitivity, low dispersion and high photon counting rate. The PLATO prototype matrix is composed of 16 × 18 pixels with a 70 μm pixel pitch. New techniques have been used in analog sensitive blocks to minimize noise coupling through supply rails and substrate, and to suppress threshold dispersion across the matrix. The PLATO ASIC is designed in CMOS 0.13 μm technology and was submitted for a fabrication run in June 2016. The chip is designed to be bump-bonded to a silicon sensor. This paper presents pixel architecture as well as simulation results while highlighting novel solutions.

  5. The effect of x-ray irradiation on proliferation and differentiation of epithelial cells in mouse skin

    International Nuclear Information System (INIS)

    Tanabe, Akira

    1980-01-01

    To elucidate radiation injuries and the recovery mechanism of epithelial cells exposed to 150 R or 450 R of x-ray, the epidermal proliferative unit (EPU) in the backs of mice was analysed histologically and dynamically by measuring the labelled index of cells with 3 H-thymidine and measuring differentiation index of cells. EPU was normal for 6 days after irradiation with both 150 R and 450 R. However, partial hyperplasia and EPU disorders in a range consistent with hyperplasia appeared in segmented preparations 7 days after irradiation. Both doses inhibited cell differentiation for 5 days after irradiation. Cell proliferation, which was higher than the normal rate, peaked 7 days after irradiation with 150 R and 9 days after irradiation with 540 R. Cell proliferation returned to normal 10 days after irradiation. DNA synthesis was inhibited one day after irradiation with both 150 R and 450 R, but it returned to normal 3 days after irradiation. There was an overshoot of DNA synthesis, but synthesis returned to normal 9 days after irradiation with 150 R and 12 days after irradiation with 450 R. EPU disorders returned to normal according to normalization of cell differentiation and DNA synthesis. (Tsunoda, M.)

  6. Tuning of the optical properties of In-rich In{sub x}Ga{sub 1−x}N (x=0.82−0.49) alloys by light-ion irradiation at low energy

    Energy Technology Data Exchange (ETDEWEB)

    De Luca, Marta; Polimeni, Antonio; Capizzi, Mario [Dipartimento di Fisica, Sapienza Università di Roma, P.le A. Moro 2, 00185 Roma (Italy); Pettinari, Giorgio [School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD (United Kingdom); Ciatto, Gianluca; Fonda, Emiliano [Synchrotron SOLEIL, L' Orme des Merisiers, Saint-Aubin, BP 48, 91192 Gif sur Yvette Cedex (France); Amidani, Lucia; Boscherini, Federico [Department of Physics and CNISM, University of Bologna, V. le C. Berti Pichat 6/2, 40127 Bologna (Italy); Filippone, Francesco; Bonapasta, Aldo Amore [CNR-Istituto di Struttura della Materia (ISM), Via Salaria Km 29.5, CP 10, I-00016 Monterotondo Stazione (Italy); Knübel, Andreas; Cimalla, Volker; Ambacher, Oliver [Fraunhofer Institute for Applied Solid State Physics, Tullastr. 72, 79108 Freiburg (Germany); Giubertoni, Damiano; Bersani, Massimo [CMM - Fondazione Bruno Kessler, Trieste, via Sommarive 18, 38100, Povo Trento (Italy)

    2013-12-04

    The effects of low-energy irradiation by light ions (H and He) on the properties of In-rich In{sub x}Ga{sub 1−x}N alloys are investigated by optical and structural techniques. H-irradiation gives rise to a remarkable blue-shift of light emission and absorption edge energies. X-ray absorption measurements and first-principle calculations address the microscopic origin of these effects.

  7. Tuning of the optical properties of In-rich InxGa1−xN (x=0.82−0.49) alloys by light-ion irradiation at low energy

    International Nuclear Information System (INIS)

    De Luca, Marta; Polimeni, Antonio; Capizzi, Mario; Pettinari, Giorgio; Ciatto, Gianluca; Fonda, Emiliano; Amidani, Lucia; Boscherini, Federico; Filippone, Francesco; Bonapasta, Aldo Amore; Knübel, Andreas; Cimalla, Volker; Ambacher, Oliver; Giubertoni, Damiano; Bersani, Massimo

    2013-01-01

    The effects of low-energy irradiation by light ions (H and He) on the properties of In-rich In x Ga 1−x N alloys are investigated by optical and structural techniques. H-irradiation gives rise to a remarkable blue-shift of light emission and absorption edge energies. X-ray absorption measurements and first-principle calculations address the microscopic origin of these effects

  8. 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)

  9. Irradiation of gold nanoparticles by x-rays: Monte Carlo simulation of dose enhancements and the spatial properties of the secondary electrons production.

    Science.gov (United States)

    Leung, Michael K K; Chow, James C L; Chithrani, B Devika; Lee, Martin J G; Oms, Barbara; Jaffray, David A

    2011-02-01

    The aim of this study is to understand the characteristics of secondary electrons generated from the interaction of gold nanoparticles (GNPs) with x-rays as a function of nanoparticle size and beam energy and thereby further the understanding of GNP-enhanced radiotherapy. The effective range, deflection angle, dose deposition, energy, and interaction processes of electrons produced from the interaction of x-rays with a GNP were calculated by Monte Carlo simulations. The GEANT4 code was used to simulate and track electrons generated from a 2, 50, and 100 nm diameter GNP when it is irradiated with a 50 kVp, 250 kVp, cobalt-60, and 6 MV photon beam in water. When a GNP was present, depending on the beam energies used, secondary electron production was increased by 10- to 2000-fold compared to an absence of a GNP. Low-energy photon beams were much more efficient at interacting with the GNP by two to three orders of magnitude compared to MV energies and increased the deflection angle. GNPs with larger diameters also contributed more dose. The majority of the energy deposition was outside the GNP, rather than self-absorbed by the nanoparticle. The mean effective range of electron tracks for the beams tested ranged from approximately 3 microm to 1 mm. These simulated results yield important insights concerning the spatial distributions and elevated dose in GNP-enhanced radiotherapy. The authors conclude that the irradiation of GNP at lower photon energies will be more efficient for cell killing. This conclusion is consistent with published studies.

  10. 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.

  11. 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.

  12. 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.

  13. Assessment of irradiation of children certain organs resulted from X-ray chest examination

    International Nuclear Information System (INIS)

    Kostenetskij, M.I.; Sukhomlina, A.N.

    1983-01-01

    Specific absorbed doses were studied for cerfain critical organs due to X-ray chest examination of children. Dosimetric investigations were conducted using water-plexiglas phantom, imitating the body of 12 year old child. The error of measurements doesn't exceed +-3%, the low reshold of sensitivity equals 0.005 r/min. RUM-20 apparatus was used as an X-ray source. It was established that specific absorbed doses for lungs, as well as for mammary abd thyroid glands were the maximum ones under direct radiation. Doses for gonads are hundred times less, than those for lungs. It is recommended to shield both gonads and thyroid gland. Data on dose equivalents testify to the fact that to decrease the summary dose equivalent it is necessary to use the minimum radiation fields, decreasing voltage and exposition abd increasing source-surface distance with regard to the maximum information of the film image

  14. Chromosomal aberrations of the Chinese hamster cell line V79 after irradiation with X-rays and heavy ions

    International Nuclear Information System (INIS)

    Mueller, W.

    1985-02-01

    The study on hand examines chromosomal aberrations in Chinese hamster 79 cells. Irradiation involved a number of heavy ions ranging from neon to uranium with an energy variation between 0.3 and 20 MeV/u. Linear energy transfer ranged from 270 to 16,300 keV/μm. X-ray tests were run for reasons of comparison. Experiments showed the following results: 1) Aberration rate increases in dependence of nuclear charge number or LET resp. 2) The distribution of the chromosome-damage instances found differed markedly from corresponding measurements following irradiation with thinly ionizing radiation. In contrast to x-irradiation, it is possible, therefore, to obtain high aberration yields in preparations made immediately after irradiation. 3) The maximum of aberration yield after heavy-ion irradiation could be shown to occur as early as 4h after irradiation. This is true in x-irradiation for but small doses. 4) The radiation-sensitizing effect of caffeine and its action on the repair system of the cell could be confirmed for x-irradiation and could be described for heavy ions for the first time. 5) The radiation-protection effect of cysteamine could be re-affirmed for thinly ionizing radiation, however, it could not be verified for heavy ions. 6) Irradiation of cells by means of particles of a defined range supports the hypothesis that the particularly radiation-sensitive regions of the nucleus membrane constitute the cell's crucial target. (orig./MG) [de

  15. Homogenious focusing with a transient soft X-ray laser for irradiation experiments

    Czech Academy of Sciences Publication Activity Database

    Kazamias, S.; Cassou, K.; Guilbaud, O.; Klisnick, A.; Ros, D.; Plé, F.; Jamelot, G.; Rus, Bedřich; Kozlová, Michaela; Stupka, Michal; Mocek, Tomáš; Douillet, D.; Zeitoun, P.; Joyeux, D.; Phalippou, D.

    2006-01-01

    Roč. 263, - (2006), s. 98-104 ISSN 0030-4018 R&D Projects: GA MŠk(CZ) LC528; GA ČR GA202/05/2316 Institutional research plan: CEZ:AV0Z10100523 Keywords : soft X-Ray laser * focusing * laser plasma * UV radiation * beam profile Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.480, year: 2006

  16. Optimized K (alpha) x-ray flashes from femtosecond-laser-irradiated foils

    Czech Academy of Sciences Publication Activity Database

    Lu, W.; Nicoul, M.; Shymanovich, U.; Tarasevitch, A.; Zhou, P.; Sokolowski-Tinten, K.; von der Linde, D.; Mašek, Martin; Gibbon, P.; Teubner, U.

    2009-01-01

    Roč. 80, č. 2 (2009), 026404/1-026404/10 ISSN 1539-3755 R&D Projects: GA MŠk(CZ) LC528 Institutional research plan: CEZ:AV0Z10100523 Keywords : copper * electron density * high-speed optical techniques * plasma density * plasma production by laser * plasma simulation * plasma x-ray sources * titanium Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 2.400, year: 2009

  17. Effect of low X-ray dose irradiation on properties triglycine sulfate doped by chromium

    CERN Document Server

    Kamysheva, L N; Golitsyna, O M

    2002-01-01

    One studied effect of X-ray low dose on pulse re-polarization in triglycine sulfate crystals (TGS) with various concentration of chromium ions. It is shown that within 20.0 deg C-T sub c temperature range alpha activation field values depend unambiguously on radiation dose for various polarity switching current pulses. One detected decrease of unipolarity of TGS crystal caused by chromium ions due to interaction of radiation defects with impurity ones

  18. A simple irradiation facility for radiobiological experiments with low energy protons from a cyclotron

    International Nuclear Information System (INIS)

    Mukherjee, B.

    1982-01-01

    An experimental facility for irradiation of small biological targets with low-energy protons has been developed. The depth-dose distribution in soft-tissue is calculated from the proton energy spectrum. (orig.)

  19. Radiosensitivity of grapevines. Empirical modelling of the radiosensitivity of some clones to x-ray irradiation. Pt. 1

    International Nuclear Information System (INIS)

    Koeroesi, F.; Jezierska-Szabo, E.

    1999-01-01

    Empirical and formal (Poisson) models were utilized, applying experimental growth data to characterize the radiosensitivity of six grapevine clones to X-ray irradiation. According to the radiosensitivity constants (k), target numbers (n) and volumes, GR 37 doses and energy deposition, the following radiosensitivity order has been found for various vine brands: Chardonnay clone type < Harslevelue K. 9 < Koevidinka K. 8 < Muscat Ottonel clone type < Irsai Oliver K. 11 < Cabernet Sauvignon E. 153. The model can be expanded to describe the radiosensitivity of other plant species and varieties, and also the efficiency of various radioprotecting agents and conditions. (author)

  20. The status of Tsukuba BNCT trial: BPA-based boron neutron capture therapy combined with X-ray irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, T., E-mail: tetsu_tsukuba@yahoo.co.jp [Department of Neurosurgery, Graduate School of Comprehensive Human Science, University of Tsukuba, Tennodai 1-1-1, Tsukuba (Japan)] [Department of Radiation Oncology, Graduate School of Comprehensive Human Science, University of Tsukuba, Tennodai 1-1-1, Tsukuba (Japan); Nakai, K. [Department of Neurosurgery, Graduate School of Comprehensive Human Science, University of Tsukuba, Tennodai 1-1-1, Tsukuba (Japan); Nariai, T. [Department of Neurosurgery, Tokyo Medical and Dental University, Yushima 1-5-45, Bunkyo-ku, Tokyo (Japan); Kumada, H.; Okumura, T.; Mizumoto, M.; Tsuboi, K. [Department of Radiation Oncology, Graduate School of Comprehensive Human Science, University of Tsukuba, Tennodai 1-1-1, Tsukuba (Japan); Zaboronok, A.; Ishikawa, E.; Aiyama, H.; Endo, K.; Takada, T.; Yoshida, F.; Shibata, Y.; Matsumura, A. [Department of Neurosurgery, Graduate School of Comprehensive Human Science, University of Tsukuba, Tennodai 1-1-1, Tsukuba (Japan)

    2011-12-15

    The phase II trial has been prepared to assess the effectiveness of BPA (250 mg/kg)-based NCT combined with X-ray irradiation and temozolomide (75 mg/m{sup 2}) for the treatment of newly diagnosed GBM. BPA uptake is determined by {sup 18}F-BPA-PET and/or {sup 11}C-MET-PET, and a tumor with the lesion to normal ratio of 2 or more is indicated for BNCT. The maximum normal brain point dose prescribed was limited to 13.0 Gy or less. Primary end point is overall survival.

  1. Study of HeLa cells clone survival after X-ray irradiation in the presence of cisplatin

    Science.gov (United States)

    Baulin, A. A.; Sukhikh, E. S.; Vasilyev, S. A.; Sukhikh, L. G.; Sheino, I. N.

    2017-09-01

    Radiation therapy in the presence of heavy elements nuclei (Z > 53) is widely developed these days. The presence of such nuclei in cancer cells results in the local increase of energy release from primary photon beam thus increasing relative biological efficiency. In this paper we present the preliminary results of the cell survival study while irradiating cells by X-Ray photon beam in the presence of cisplatin (Pt, Z = 78). The preliminary results show the decrease of the cell survival in the presence of both radiation and cisplatin.

  2. Production of haploid plant of 'Banpeiyu' pummelo [Citrus maxima (Burm.) Merr.] by pollination with soft X-ray-irradiated pollen

    International Nuclear Information System (INIS)

    Yahata, Masaki; Yasuda, Kiichi; Kunitake, Hisato; Nagasawa, Kohji; Harusaki, Seiichi; Komatsu, Haruki

    2010-01-01

    To induce haploid plants in Citrus maxima (Burm.) Merr. 'Banpeiyu', we evaluated the effect of pollination with soft X-ray-irradiated pollen on fruit set and seed development, and carried out ovule culture. When 'Banpeiyu' pummelo pistils were pollinated with X-ray-irradiated pollen of 'Fukuhara' sweet orange [C. sinensis (L.) Osbeck], the exposure doses affected the fruit set. The number of seeds per fruit was also affected by the exposure dose, and tended to decrease as the dose increased; however, all developed seeds obtained from these crosses were diploid. In the ovule culture of 'Banpeiyu' pummelo, six embryoids shown haploidy were obtained in all treatments. One haploid plantlet with 9 chromosomes was regenerated from an embryoid in a culture of ovules established 40 days after pollination with 400 Gray (Gy)-irradiated pollen of 'Tosa-buntan' pummelo (C. maxima). This haploid was suggested to be derived from 'Banpeiyu' pummelo by random amplified polymorphic DNA (RAPD) and cleaved amplified polymorphic sequence (CAPS) analysis. (author)

  3. Synchrotron X-ray diffraction investigations on strains in the oxide layer of an irradiated Zircaloy fuel cladding

    International Nuclear Information System (INIS)

    Chollet, Mélanie; Valance, Stéphane; Abolhassani, Sousan; Stein, Gene; Grolimund, Daniel; Martin, Matthias; Bertsch, Johannes

    2017-01-01

    For the first time the microstructure of the oxide layer of a Zircaloy-2 cladding after 9 cycles of irradiation in a boiling water reactor has been analyzed with synchrotron micro-X-ray diffraction. Crystallographic strains of the monoclinic and to some extent of the tetragonal ZrO 2 are depicted through the thick oxide layer. Thin layers of sub-oxide at the oxide-metal interface as found for autoclave-tested samples and described in the literature, have not been observed in this material maybe resulting from irradiation damage. Shifts of selected diffraction peaks of the monoclinic oxide show that the uniform strain produced during oxidation is orientated in the lattice and displays variations along the oxide layer. Diffraction peaks and their shifts from families of diffracting planes could be translated into a virtual tensor. This virtual tensor exhibits changes through the oxide layer passing by tensile or compressive components. - Highlights: •A Zircaloy-2 cladding irradiated 9 cycles was investigated thanks to synchrotron X-ray diffraction. •Microstructure and uniform strain through the oxide layer is revealed. •The m-ZrO 2 uniform strain is oriented presenting compression along the (−111) plane. •Virtual tensor is built based on reflecting planes of families of grains. •Tensor components vary from tensile to compressive along the oxide layer.

  4. Synchrotron X-ray diffraction investigations on strains in the oxide layer of an irradiated Zircaloy fuel cladding

    Energy Technology Data Exchange (ETDEWEB)

    Chollet, Mélanie, E-mail: melanie.chollet@psi.ch [Paul Scherrer Institute, NES, 5232 Villigen (Switzerland); Valance, Stéphane; Abolhassani, Sousan; Stein, Gene [Paul Scherrer Institute, NES, 5232 Villigen (Switzerland); Grolimund, Daniel [Paul Scherrer Institute, SLS, 5232 Villigen (Switzerland); Martin, Matthias; Bertsch, Johannes [Paul Scherrer Institute, NES, 5232 Villigen (Switzerland)

    2017-05-15

    For the first time the microstructure of the oxide layer of a Zircaloy-2 cladding after 9 cycles of irradiation in a boiling water reactor has been analyzed with synchrotron micro-X-ray diffraction. Crystallographic strains of the monoclinic and to some extent of the tetragonal ZrO{sub 2} are depicted through the thick oxide layer. Thin layers of sub-oxide at the oxide-metal interface as found for autoclave-tested samples and described in the literature, have not been observed in this material maybe resulting from irradiation damage. Shifts of selected diffraction peaks of the monoclinic oxide show that the uniform strain produced during oxidation is orientated in the lattice and displays variations along the oxide layer. Diffraction peaks and their shifts from families of diffracting planes could be translated into a virtual tensor. This virtual tensor exhibits changes through the oxide layer passing by tensile or compressive components. - Highlights: •A Zircaloy-2 cladding irradiated 9 cycles was investigated thanks to synchrotron X-ray diffraction. •Microstructure and uniform strain through the oxide layer is revealed. •The m-ZrO{sub 2} uniform strain is oriented presenting compression along the (−111) plane. •Virtual tensor is built based on reflecting planes of families of grains. •Tensor components vary from tensile to compressive along the oxide layer.

  5. Effects of large dose X-ray irradiation of head on reproductive endocrine function in male rats

    International Nuclear Information System (INIS)

    Gong Shouliang; Liu Shuzheng

    1990-01-01

    The change in hypothalamic dopamine (DA), serum gonadotrophins (LH, FSH), urine testosterone (TS), testicular cAMP, and pituitary and testis indices at different intervals after irradiation of head with 10 Gy X-rays in male rats were observed. The results showed that DA and gonadotrophins changed essentially in the same direction following head irradiation. The change in testicular cAMP content which coincided with that of serum gonadotrophins was especially interesting. The urine TS content changed in the same direction with that of serum LH. The pituitary and testicular indices showed no marked changes. The above data illustrated that an acute irradiation of head could cause marked changes leading to release of hypothalamic DA and anterior pituitary gonadotrophins. The changes in testicular cAMP may be secondary to those of the LH release, and TS production and secretion may be closely related to the change in testicular cAMP under the regulation of gonadotrophins

  6. Study on stable fly eradication by sterile-male technique. Effects of X-ray irradiation on the stable fly

    Energy Technology Data Exchange (ETDEWEB)

    Chung, K H; Ryu, J; Kwon, S H [Korea Atomic Energy Research Inst., Seoul (Republic of Korea)

    1975-01-01

    This experiment was performed to investigate the X-ray sensitivities at the various stages of life cycle and to determine the sterillizing dose of stable fly, Stomoxys calcitrans(L). A dose of 300 rad caused about 50% mortality in 2-hour-old eggs as measured by egg hatch, and 100% mortality was obtained with a dose of 1 Krad. Sub-lethal dose (LDsub(50)) for the pupal age at irradiation. A significant reduction of egg hatch by 1.5% was observed when treated males with 3 Krad at pupal stage were mated to untreated virgin females. On the other hand, 100% sterility in females was resulted by Krad irradiation and oviposition was completely inhibited with 3 Krad. Thus, both sexes of stable fly could be sterilized with a dose of 4 Krad irradiated 50 3-5 days old pupae.

  7. Effect of X-rays on oogenesis of Tilapia mossambica Peters 2. Irradiation of 15 days old larvae

    Energy Technology Data Exchange (ETDEWEB)

    Chmilevskij, D.A. (Leningradskij Gosudarstvennyj Univ. (USSR). Biologicheskij Nauchno-Issledovatel' skij Inst.)

    1982-07-01

    Tilapia larvae of 15 days old after hatching were exposed to x-rays at a dose of 350 R and gonad state in fishes of up to 120 days old was studied. The largest part of sex cells was perished in fishes of 20-30 days old. At the age of 60 days the process of gonad recovery began in consequence of which the number of sex cells in experimental fishes till the end of experiment (fishes of 120 days old after hatching) was the same as in control fishes of the same age. However, unlike the experiment with irradiation of larvae of 6 days old, during irradiation of larvae of 15 days old there was no complete recovery of gonads-oocytes of the irradiated fishes didn't reach the stage of oocyte development under control.

  8. Effect of X-rays on oogenesis of Telapia mossambica Peters 2. Irradiation of 15 days old larvae

    International Nuclear Information System (INIS)

    Chmilevskij, D.A.

    1982-01-01

    Tilapia larvae of 15 days old after hatching were exposed to x-rays at a dose of 350 R and gonad state in fishes of up to 120 days old was studied. The largest part of sex cells was perished in fishes of 20-30 days old. At the age of 60 days the process of gonad recovery began in consequence of which the number of sex cells in experimetnal fishes tall the end of experiment (fishes of 120 days old after hatching) was the same as in control fishes of the same age. However, unlike the experiment with irradiation of larvae of 6 days old, during irradiation of larvae of 15 days old there was no complete recovery of gonads-oocutes of the irradiated fishes didn't reach the stage of oocyte development under control

  9. The effect of X-ray irradiation on a red cell component in WB, WRC and LPRC

    International Nuclear Information System (INIS)

    Tayama, Tatsuya; Toyota, Kuroh; Nagahashi, Hisakata; Masuyama, Tetsuya; Haneda, Kenji; Juji, Takeo.

    1990-01-01

    In spite of the use of X-ray irradiation on blood products, few data about its effect on components are reported. We need more informations about a quality of irradiated red cell components. This study shows in vitro changes of irradiated red cell component in WB, WRC and LPRC as the minimum dose of 1,500, 3,000, and 5,000 rads. The fact as follows were observed in response to irradiated doses: 1) increased fragility of red cell membrane, 2) increased amount of plasma K and plasma Hb, and 3) decrease of ATP in WB.2,3-DPG, glucose, pH, Ht and Cl. The numbers of RBC, WBC and Platelet were not affected by irradiation with doses between 1,500 and 5,000 rads. According to these results, the followings are recommended: 1) irradiation with 1,500 rads is a proper method for WB, 2) in order to avoid the risk of increased plasma K, WB should be used within 1 week after irradiation, and WRC and LPRC should be used 24 hours after irradiation. (author)

  10. Irradiation of micro-organisms with mono-energetic X-rays; biological consequences of the Auger effect

    Energy Technology Data Exchange (ETDEWEB)

    Halpern, A; Muetze, B [Kernforschungsanlage Juelich G.m.b.H. (Germany, F.R.)

    1978-07-01

    The radiation resonance effect reported previously for isolated biomolecules has now for the first time been observed in a cellular system. Dried bacteria, Micrococcus denitrificans, in which TdR in DNA was partially substituted by BUdR, were subjected to mono-energetic X-rays of energies below or above the K-edge for Br. Subsequently, the colony-forming ability was assayed. For photon energy slightly above the K-edge, the lethality/rad was greater than that below the K-edge. This is interpreted in terms of the Auger effect initiated selectively by photo-absorption in constituent Br atoms. The differential absorption of low-energy photons in constituent atoms of DNA is also discussed.

  11. Effects of PTEN transfer on cell cycle progression and expression of P27kipl followed by X-ray irradiation

    International Nuclear Information System (INIS)

    Tian Mei; Wu Congmei; Liu Linlin; Piao Chunji; Li Xiuyi

    2007-01-01

    Objective: To investigate the effect of pEgr-hPTEN stable transfer combined with irradiation on the cell cycle progression and the expression of cell cycle kinase inhibitor P27 kipl protein of SHG-44 human glioma cells. Methods: pEgr-hPTEN vector containing the exogenous wild type PTEN gene was transfected into SHG-44 cells under mediation of lipofectamine in vitro, the positive cell clones were selected and amplified by using G418. Western blotting was used to measure the expression of PTEN protein. Transmission electron microscope was adopted to detect the cell ultrastructural changes and flow cytometry was adopted to analysis the changes of cell cycle progression and the expression of P27 kipl in SHG-44-sPTEN cells followed by different doses of X-ray irradiation. Results: Egr-1 promoter could be induced and activated by irradiation and then enhanced the expression of downstream PTEN gene within 5 Gy. The ultrastructure of SHG-44-sPTEN cells had many degenerative changes and many early apoptotic changes including the chromosome condensate around the nuclear envelope. pEgr-hPTEN stable transfer combined with X-ray irradiation could significantly induce G 1 arrest. The expression of P27 kipl proteins increased in SHG-44-sPTEN stable transfected cells. Conclusion: PTEN stable transfer combined with irradiation can significantly induce G 1 arrest. The molecular basis may be correlated with the enhanced expression of PTEN induced by irradiation and increased expression of cell cycle kinase inhibitor P27 kipl . (authors)

  12. Phase-changes in cell cycle of wound tissue irradiated with 5.21 Gy 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 phase-changes in cell cycle of wound tissue which was locally irradiated with 5.21 Gy soft X-rays. Methods: Flow cytometry and PI staining were used to analyze cell cycle. Cell proliferation was determined with BrdU labeling. Results: During 3-9 days after irradiation, the percentage of the G 0 /G 1 phase cells in wound of the control side decreased while the percentage of S phase cells increased and reached the highest value on day 9. The percentage of G 2 /M phase cells also increased, and reached its peak on day 15. The percentage of G 0 /G 1 phase cell increased in wound of the irradiation side and was higher than that of the control wound, meanwhile the percentages of S and G 2 /M cells were significantly lower than those of the control wound. In the period of 12-22 days after wounding, the percentage of S phase cells increased and reached its peak value on the 22 th day. When most of cells were in S phase and arrested dramatically. Through the whole healing process, the percentage of G 2 /M in wound of the irradiation side was lower than that of the non-irradiated wound. The BrdU-positive cells were fibroblasts, endothelial cells and smooth muscle cells. Conclusion: These results suggest that G 1 block, S phase arrest, and switch of G 2 /M with suppression of mitotic activity of these cells are induced by local 5.21 Gy soft X-ray irradiation. Therefore, wound healing delay is induced partly by cell cycle arrest

  13. Medium from X-rayed cultures induces DNA strand-breaks in non-irradiated HeLa cells

    International Nuclear Information System (INIS)

    Ikushima, T.; Okuyama, K.; Tanizaki, Y.

    2002-01-01

    There is growing evidence to indicate that several types of responses are induced by ionizing radiation in non-irradiated cells. Such bystander effects include the killing of non-irradiated cells, the induction of sister chromatid exchanges and chromosomal aberrations, and the induction of gene mutations and chromosomal instability and enhanced cell growth. In the present study, we assessed whether the medium from irradiated cultures can induce DNA strand-breaks in non-irradiated cells, using single-cell gel electrophoresis assay (comet assay). HeLa cells in culture were irradiated with 0.5 to 8 Gy of 140 kVp X-rays and one hour later, the medium was taken from the irradiated culture, passed through a filter and transferred to the parallel culture of non-irradiated HeLa cells as non-target cells. After incubation for 30 min, the comet assay was performed under alkaline and neutral conditions. Such treatments resulted in a dose-dependent increase in tail moment under either alkaline or neutral condition, indicating the induction of DNA single- or double-strand breaks, respectively. It was also shown that the clonogenic survival was reduced in the cells cultured in the medium from irradiated cultures. Such a change was not detected at all when medium alone was irradiated. These results provided disputed evidence that irradiated cells released certain genotoxic factor(s) into the culture medium that can induce DNA strand breaks leading to cell death. Our results suggest that physical contact between irradiated and non-irradiated cells may not be necessary for the bystander effects observed in this study. It appears that bystander responses may be mediated by multiple mechanisms

  14. 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

  15. Comparison of the air-kerma standards of the PTB and the BIPM in the low-energy X-ray range

    International Nuclear Information System (INIS)

    Burns, D.T.; Bueermann, L.; Kramer, H.M.; Lange, B.

    2001-09-01

    A direct comparison has been made between the air-kerma standards of the Physikalisch-Technische Bundesanstalt (PTB), Germany, and the Bureau International des Poids et Mesures (BIPM) in the x-ray range from 10 kV to 50 kV. Additional measurements were made at 80 kV and 100 kV to provide information on the electron-loss correction for the BIPM standard at these qualities. The comparison took place at the BIPM in March 1999 using the reference conditions recommended by the CCRI. There is general agreement at the level of one standard uncertainty, although there is a significant trend in the results between 30 kV and 50 kVa. This is in part due to the treatment of fluorescence radiation. The effect of fluorescence for the BIPM standard has been calculated using the Monte Carlo code EGSnrc and the fluorescence correction calculated in this way and the effect of including these new values in the present comparison are given. It should be noted, however, that these new correction factors for the BIPM standard have not yet been adopted. The result at 10 kV is significantly different from the others. This is not uncommon and raises a number of possibilities, for example the large corrections for air attenuation and guard wire attenuation, or unexplained aperture effects that have arisen in certain comparisons. In this respect, it is possible that the uncertainties for the 10 kV quality are underestimated. The measurements at 80 kV and 100 kV were made principally to test the correction factors for the BIPM standard, making use of the fact that the large electrode separation of the PTB PK100 chamber results in very little electron loss. (authors)

  16. A new light on Alkaptonuria: A Fourier-transform infrared microscopy (FTIRM) and low energy X-ray fluorescence (LEXRF) microscopy correlative study on a rare disease.

    Science.gov (United States)

    Mitri, Elisa; Millucci, Lia; Merolle, Lucia; Bernardini, Giulia; Vaccari, Lisa; Gianoncelli, Alessandra; Santucci, Annalisa

    2017-05-01

    Alkaptonuria (AKU) is an ultra-rare disease associated to the lack of an enzyme involved in tyrosine catabolism. This deficiency results in the accumulation of homogentisic acid (HGA) in the form of ochronotic pigment in joint cartilage, leading to a severe arthropathy. Secondary amyloidosis has been also unequivocally assessed as a comorbidity of AKU arthropathy. Composition of ochronotic pigment and how it is structurally related to amyloid is still unknown. We exploited Synchrotron Radiation Infrared and X-Ray Fluorescence microscopies in combination with conventional bio-assays and analytical tools to characterize chemical composition and morphology of AKU cartilage. We evinced that AKU cartilage is characterized by proteoglycans depletion, increased Sodium levels, accumulation of lipids in the peri-lacunar regions and amyloid formation. We also highlighted an increase of aromatic compounds and oxygen-containing species, depletion in overall Magnesium content (although localized in the peri-lacunar region) and the presence of calcium carbonate fragments in proximity of cartilage lacunae. We highlighted common features between AKU and arthropathy, but also specific signatures of the disease, like presence of amyloids and peculiar calcifications. Our analyses provide a unified picture of AKU cartilage, shedding a new light on the disease and opening new perspectives. Ochronotic pigment is a hallmark of AKU and responsible of tissue degeneration. Conventional bio-assays have not yet clarified its composition and its structural relationship with amyloids. The present work proposes new strategies for filling the aforementioned gap that encompass the integration of new analytical approaches with standardized analyses. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. 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.

  18. Comparison of recovery in the rat lens epithelium after x-ray, fission neutron, or /sup 56/Fe particle irradiation

    International Nuclear Information System (INIS)

    Riley, E.F.; Lindgren, A.L.; Ainsworth, E.J.

    1985-01-01

    The authors are comparing the radiobiological effectiveness of 10 Gy (1000 rads) of 250 kVp X-rays, 2 Gy (200 rads) of fission neutrons, and 1.5 Gy (150 rds) of 600 MeV /sup 56/Fe particles (LET about 180-200 keV/μm). They are evaluating the persistence of latent radiation damage and the very slow recovery (> 1 month) in cells of the central zone of the rat lens epithelium. The central zone is essentially a G/sub o/ population of cells (1 mitotic figure per 2000 cells). These cells normally respond to the mitogenic stimulus of wounding with a ''burst'' of DNA synthesis at 14 hours and a ''burst'' of mitosis at 24 hours after wounding. Irradiation before wounding causes a delay and suppression of the response. With increasing time between irradiation and wounding, the authors note less delay and less suppression of the response. They also note fewer abnormal mitotic figures. For example, at 28 days the X-irradiated, neutron irradiated, and iron irradiated cells developed respectively, 39%, 36%, and 21% fewer abnormal mitotic figures than at 7 days post-irradiation. Slower recovery after /sup 56/Fe particle irradiation is indicated. They are now comparing the amounts of delay and suppression of the responses after exposure to the different radiations

  19. Transforming growth factor beta 1 expression and inflammatory cells in tooth extraction socket after X-ray irradiation

    Directory of Open Access Journals (Sweden)

    Ramadhan Hardani Putra

    2016-06-01

    Full Text Available Background: Radiographic examination is often used in dentistry to evaluate tooth extraction complications. X-ray used in radiographic examination, however, has negative effects, including damage to DNA and inflammatory response during wound healing process. Purpose: This study aimed to analyze the effects of X-ray irradiation on transforming growth factor beta 1 (TGF-ß1 expression and number of inflammatory cells in tooth extraction sockets. Method: Thirty rats were divided into three groups, which consist of control group (with a radiation of 0 mSv, treatment group 1 (with a radiation of 0.08 mSv, and treatment group 2 (with a radiation of 0.16 mSv. These rats in each group were sacrificed on days 3 and 5 after treatment. Inflammatory cells which were observed in this research were PMN, macrophages, and lymphocytes. Histopathological and immunohistochemical examinations were used to calculate the number of inflammatory cells and TGF-ß1 expression. Obtained data were analyzed using SPSS 16.0 software with one way ANOVA and Tukey’s HSD tests. Result: There was no significant decrease in the number of PMN. On the other hand, there were significant decreases in the number of macrophages and lymphocytes in the sacrificed group on day-5 with the radiation of 0.16 mSv. Similarly, the most significant decreased expression of TGF-ß1 was found in the group sacrificed on day 5 with the radiation of 0.16 mSv. Conclusion: X-ray irradiation with 0.08 mSv and 0.16 mSv doses can decrease TGF-ß1 expression and number of inflammatory cells in tooth extraction sockets on day 3 and 5 post extraction.

  20. In situ investigation of the surface silvering of late Roman coins by combined use of high energy broad-beam and low energy micro-beam X-ray fluorescence techniques

    Energy Technology Data Exchange (ETDEWEB)

    Romano, F.P., E-mail: romanop@lns.infn.it [IBAM, CNR, Via Biblioteca 4, 95124 Catania (Italy); LNS, INFN, Via S. Sofia 62, 95123 Catania (Italy); Garraffo, S. [ITABC, CNR, Via Salaria km 29.300, 00016 Monterotondo, Roma (Italy); Pappalardo, L. [IBAM, CNR, Via Biblioteca 4, 95124 Catania (Italy); LNS, INFN, Via S. Sofia 62, 95123 Catania (Italy); Rizzo, F. [LNS, INFN, Via S. Sofia 62, 95123 Catania (Italy); Dipartimento di Fisica e Astronomia, Universita di Catania, Via S. Sofia 64, 95123 Catania (Italy)

    2012-07-15

    The compositional analysis of archeological metals performed with the X-ray Fluorescence technique (XRF) provides information on the ancient technology. One of the most interesting case-study concerns the techniques used by Romans for silvering the surface of coins. Different metallurgical processes have been suggested in previous studies. Recently the investigation has been addressed to the mercury-silvering and to its possible use in the mass-production of coins minted during the late period (after 294 AD). In the present paper the non-destructive investigation of the silvering process used for manufacturing the Roman nummi - the important typology of coin introduced by Diocletian in his monetary reform - is approached by the combined use of the standard X-Ray Fluorescence (XRF) and the low energy micro-X-Ray Fluorescence (LE-{mu}XRF) portable methods. The research was focused on the systematic determination of the mercury presence in a large number of samples and on its correlation with silver in the surface of the coins. 1041 Roman nummi belonging to the Misurata Treasure were analyzed in situ, at the Leptis Magna Museum (Al Khums, Libya). The treasure, composed of about 108 thousand silvered coins, gives the unique opportunity to study the Roman coinage in a wide interval of time (about 40 years in the period 294-333 AD) and in almost all the imperial mints operating in the Roman world. - Highlights: Black-Right-Pointing-Pointer Custom-building of a high energy broad-beam and a low energy micro-beam XRF Black-Right-Pointing-Pointer In situ analysis of the silvering methods in late Roman nummi with plated surfaces Black-Right-Pointing-Pointer The broad-beam XRF was applied for the detection of mercury traces in the coin alloy. Black-Right-Pointing-Pointer The low energy micro-XRF was used to scan the surface patina of the coins. Black-Right-Pointing-Pointer The correlation between mercury and silver at the coin surface was evidenced.

  1. 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.)

  2. High-resolution 3D dose distribution measured for two low-energy x-ray brachytherapy seeds: 125I and 103Pd

    International Nuclear Information System (INIS)

    Massillon-JL, G.; Minniti, R.; Mitch, M.G.; Soares, C.G.; Hearn, R.A.

    2011-01-01

    In this work, we have investigated the 3D absorbed dose distribution around 125 I and 103 Pd low-energy photon brachytherapy seeds using a high-spatial-resolution gel scanning system to address the current difficulty in measuring absorbed dose at close distances to these sources as a consequence of high dose rate gradient. A new version of BANG-gel coupled with a small format laser CT scanner has been used. Measurements were performed with 100 μm resolution in all dimensions. In particular, radial dose function and absorbed dose rate in the plane parallel to the sources longitudinal-axis were derived at radial distances smaller than or equal to 1 cm. In addition, the energy dependence was evaluated, finding that, within measurement uncertainties, the gel response is independent of the energy for energy photon values between 20 keV and 1250 keV. We have observed that at distances larger than 1.4 mm from the source, the delivered dose is similar to predictions from published Monte Carlo calculations (MC) for the 125 I seed. For distances between 1 mm and 3 mm, differences in magnitude and shape are significant for the 103 Pd seed, where an enhancement is observed. In the enhancement region, a difference of up to 70% in the radial dose function was obtained. Such observation suggests a contribution from other radionuclides emitting beta-particles or electrons, and not considered by MC. To understand the effect, spectrometry measurements were performed. A small contribution of 102 Rh/ 102m Rh radionuclide relative to 103 Pd was observed and its importance on the absorbed dose measured at close distances to the seed is time dependent and consequently, avoids reproducible measurements. Finally, the results obtained in this work underscore the importance of using high-spatial-resolution and water-equivalent detectors for measuring absorbed dose in low-energy photon radiation fields.

  3. Histological studies on the regeneration of small-intestine epithelium of rats irradiated with sublethal doses of x rays

    Energy Technology Data Exchange (ETDEWEB)

    Lewicki, Z; Figurski, R; Sulikowska, A

    1975-01-01

    The dynamics of regeneration of small-intestine epithelium was studied in rats irradiated with x rays in sublethal doses of 550, 600, or 750 R. Sixty-two irradiated and 22 control animals were used in the experiment. They were killed 1, 2, 4, 6, 8, 14, and 25 days after the irradiation. Specimens of duodenum and jejunum were examined histologically, the sections being stained with H. E. and p.a.S. Already 1 and 2 days after irradiation the intestinal villi became shorter and deformed. The blood vessels were damaged, the enterocytes showed features of degeneration and vacuolization, the epithelium was detached by the exudate which accumulated in the strong. Irradiation markedly disturbed the regeneration of intestinal epithelium in the period from the 1st to the 6th day. Cytological calculations indicate tha on the 1st and 2nd days after irradiation the number of epithelial cells of the villi, and particularly of young cryptal ones, markedly dropped. On the 4th and 6th days increased proliferation of young cryptal cells considerably surpassed the physiological rate. The accompanying disturbances in differentiation consisted in a decreased acidophilic to basophilic cells ration and in retardation of maturation of goblet cells. The absolute number of goblet cells was increased, as well as their proportion to the number of enterocytes.

  4. Demonstration of a neonlike argon soft-x-ray laser with a picosecond-laser-irradiated gas puff target.

    Science.gov (United States)

    Fiedorowicz, H; Bartnik, A; Dunn, J; Smith, R F; Hunter, J; Nilsen, J; Osterheld, A L; Shlyaptsev, V N

    2001-09-15

    We demonstrate a neonlike argon-ion x-ray laser, using a short-pulse laser-irradiated gas puff target. The gas puff target was formed by pulsed injection of gas from a high-pressure solenoid valve through a nozzle in the form of a narrow slit and irradiated with a combination of long, 600-ps and short, 6-ps high-power laser pulses with a total of 10 J of energy in a traveling-wave excitation scheme. Lasing was observed on the 3p (1)S(0)?3s (1)P(1) transition at 46.9 nm and the 3d (1)P(1)?3p (1)P(1) transition at 45.1 nm. A gain of 11 cm(-1) was measured on these transitions for targets up to 0.9 cm long.

  5. Gene mutations, chromosome aberrations and survival after X-ray irradiation of cultured Chinese hamster cells at cysteamine protection

    International Nuclear Information System (INIS)

    Elisova, I.V.; Feoktistova, I.P.

    1983-01-01

    The culture of Chinese hamster cells (clone 431) has been used to study cysteamine action on mutagenous effect of X-rays, determined by the induction of resistance of gene mutations to 6-thioguanine and chromosomal abberations, as well as on the reproductive form of death of irradiated cells. Dose--- effect curves are obtained under conditions of irradiation with and without protector. The factor of dose alteration is 2.0 for chromosomal aberrations and cell survival, and 2.8 for gene mutations. It is sUpposed that cysteamine affects the general mechanisms, which take part in the realis zation of injuries that bring about gene mutations, chromosomal aberrations and cell lethality

  6. Dose characterization of the rad source{sup TM} 2400 X-ray irradiator for oyster pasteurization

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, Jennifer Koop [Department of Nuclear Engineering, Texas A and M University, College Station, TX 77843-3133 (United States)], E-mail: jenkoop@gmail.com; Dillon, Jeff A. [Experimental Seafood Processing Laboratory, Mississippi State University, Pascagoula, MS 39567 (United States); Blythe, Eugene K. [Coastal Research and Extension Center, Mississippi State University, South Mississippi Branch Experiment Station, Poplarville, MS 39470 (United States); Ford, John R. [Department of Nuclear Engineering, Texas A and M University, College Station, TX 77843-3133 (United States)

    2009-02-15

    The RS 2400's cylindrical X-ray source yields dose rates high enough to allow the irradiator to replace widely used gamma irradiators. Except for the leftmost 5 cm, beam uniformity is within 10% at the tube surface. At maximum operating parameters, the beam has HVL{sub 1}=13.66 mm aluminum, HC=0.47, and h{nu}{sub eq}=88.5 keV. Maximum dose rates to tissue are 65 Gy min{sup -1}{+-}3.1% at tube surface, 37 Gy min{sup -1}{+-}3.1% at center of canisters, 14.1 Gy min{sup -1}{+-}6.5% for thin-shelled oysters, and 12.3 Gy min{sup -1}{+-}6.2% for thick-shelled oysters.

  7. Interlaboratory comparison of techniques for measuring lung burdens of low-energy X-ray emitters. Part of a coordinated programme on the calibration of burdens of inhaled plutonium by external counting

    International Nuclear Information System (INIS)

    Newton, D.; Fry, F.A.; Taylor, B.T.; Eagle, M.C.; Sharma, R.C.

    1978-02-01

    An interlaboratory exercise has been conducted to assess techniques of detection and calibration in the direct measurement of lung contamination with plutonium and other nuclides emitting only low-energy X-rays. Three volunteers, of small, intermediate and large physique, inhaled an aerosol incorporating Pd-103, a 20-keV X-ray emitter, and visited 13 other laboratories in the UK, Europe and North America. Participants in the exercise were asked to estimate each subject's lung content, using their procedures for assessing burdens of plutonium, and their estimates were compared with values derived independently from measurements of Cr-51, also incorporated in the inhaled particles, by gamma-ray spectrometry. Laboratories' calibration procedures were in most cases based on elaborate thorax phantoms, and these generally led to underestimates of the subjects' contents, in some instances by a factor of three or more; only one such laboratory produced estimates in satisfactory agreement with the independently-known values. The ''phoswich'' detectors, employed by most participants, appeared to be more sensitive than gas counters. If a standard configuration were required, offering the highest sensitivity in most situations, the choice would be a pair of 12-cm diameter phoswich detectors viewing the left and right anterior surfaces of the upper thorax. No improvement in sensitivity would result from increasing the size, although larger units may offer other advantages

  8. 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

  9. 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)

  10. Tin Oxide Crystals Exposed by Low-Energy {110} Facets for Enhanced Electrochemical Heavy Metal Ions Sensing: X-ray Absorption Fine Structure Experimental Combined with Density-Functional Theory Evidence.

    Science.gov (United States)

    Jin, Zhen; Yang, Meng; Chen, Shao-Hua; Liu, Jin-Huai; Li, Qun-Xiang; Huang, Xing-Jiu

    2017-02-21

    Herein, we revealed that the electrochemical behaviors on the detection of heavy metal ions (HMIs) would largely rely on the exposed facets of SnO 2 nanoparticles. Compared to the high-energy {221} facet, the low-energy {110} facet of SnO 2 possessed better electrochemical performance. The adsorption/desorption tests, density-functional theory (DFT) calculations, and X-ray absorption fine structure (XAFS) studies showed that the lower barrier energy of surface diffusion on {110} facet was critical for the superior electrochemical property, which was favorable for the ions diffusion on the electrode, and further leading the enhanced electrochemical performance. Through the combination of experiments and theoretical calculations, a reliable interpretation of the mechanism for electroanalysis of HMIs with nanomaterials exposed by different crystal facets has been provided. Furthermore, it provides a deep insight into understanding the key factor to improve the electrochemical performance for HMIs detection, so as to design high-performance electrochemical sensors.

  11. The effect of low energy helium ion irradiation on tungsten-tantalum (W-Ta) alloys under fusion relevant conditions

    Science.gov (United States)

    Gonderman, S.; Tripathi, J. K.; Novakowski, T. J.; Sizyuk, T.; Hassanein, A.

    2017-08-01

    Currently, tungsten remains the best candidate for plasma-facing components (PFCs) for future fusion devices because of its high melting point, low erosion, and strong mechanical properties. However, continued investigation has shown tungsten to undergo severe morphology changes under fusion-like conditions. These results motivate the study of innovative PFC materials which are resistant to surface morphology evolution. The goal of this work is to examine tungsten-tantalum (W-Ta) alloys, a potential PFC material, and their response to low energy helium ion irradiation. Specifically, W-Ta samples are exposed to 100 eV helium irradiations with a flux of 1.15 × 1021 ions m-2 s-1, at 873 K, 1023 K, and 1173 K for 1 h duration. Scanning electron microscopy (SEM) reveals significant changes in surface deterioration due to helium ion irradiation as a function of both temperature and tantalum concentration in W-Ta samples. X-Ray Diffraction (XRD) studies show a slight lattice parameter expansion in W-Ta alloy samples compared to pure W samples. The observed lattice parameter expansion in W-Ta alloy samples (proportional to increasing Ta wt.% concentrations) reflect significant differences observed in the evolution of surface morphology, i.e., fuzz development processes for both increasing Ta wt.% concentration and target temperature. These results suggest a correlation between the observed morphology differences and the induced crystal structure change caused by the presence of tantalum. Shifts in the XRD peaks before and after 100 eV helium irradiation with a flux of 1.15 × 1021 ions m-2 s-1, 1023 K, for 1 h showed a significant difference in the magnitude of the shift. This has suggested a possible link between the atomic spacing of the material and the accumulated damage. Ongoing research is needed on W-Ta alloys and other innovative materials for their application as irradiation resistant materials in future fusion or irradiation environments.

  12. On the effect of x-ray irradiation on the deformation and fracture behavior of human cortical bone

    Energy Technology Data Exchange (ETDEWEB)

    Barth, Holly D.; Launey, Maximilien E.; McDowell, Alastair A.; Ager III, Joel W.; Ritchie, Robert O.

    2010-01-10

    In situ mechanical testing coupled with imaging using high-energy synchrotron x-ray diffraction or tomography imaging is gaining in popularity as a technique to investigate micrometer and even sub-micrometer deformation and fracture mechanisms in mineralized tissues, such as bone and teeth. However, the role of the irradiation in affecting the nature and properties of the tissue is not always taken into account. Accordingly, we examine here the effect of x-ray synchrotron-source irradiation on the mechanistic aspects of deformation and fracture in human cortical bone. Specifically, the strength, ductility and fracture resistance (both work-of-fracture and resistance-curve fracture toughness) of human femoral bone in the transverse (breaking) orientation were evaluated following exposures to 0.05, 70, 210 and 630 kGy irradiation. Our results show that the radiation typically used in tomography imaging can have a major and deleterious impact on the strength, post-yield behavior and fracture toughness of cortical bone, with the severity of the effect progressively increasing with higher doses of radiation. Plasticity was essentially suppressed after as little as 70 kGy of radiation; the fracture toughness was decreased by a factor of five after 210 kGy of radiation. Mechanistically, the irradiation was found to alter the salient toughening mechanisms, manifest by the progressive elimination of the bone's capacity for plastic deformation which restricts the intrinsic toughening from the formation 'plastic zones' around crack-like defects. Deep-ultraviolet Raman spectroscopy indicated that this behavior could be related to degradation in the collagen integrity.

  13. Characterization of the effects of x-ray irradiation on the hierarchical structure and mechanical properties of human cortical bone

    Energy Technology Data Exchange (ETDEWEB)

    Barth, Holly; Zimmermann, Elizabeth; Schaible, Eric; Tang, Simon; Alliston, Tamara; Ritchie, Robert

    2011-08-19

    Bone comprises a complex structure of primarily collagen, hydroxyapatite and water, where each hierarchical structural level contributes to its strength, ductility and toughness. These properties, however, are degraded by irradiation, arising from medical therapy or bone-allograft sterilization. We provide here a mechanistic framework for how irradiation affects the nature and properties of human cortical bone over a range of characteristic (nano to macro) length-scales, following x-­ray exposures up to 630 kGy. Macroscopically, bone strength, ductility and fracture resistance are seen to be progressively degraded with increasing irradiation levels. At the micron-­scale, fracture properties, evaluated using in-situ scanning electron microscopy and synchrotron x-ray computed micro-tomography, provide mechanistic information on how cracks interact with the bone-matrix structure. At sub-micron scales, strength properties are evaluated with in-situ tensile tests in the synchrotron using small-/wide-angle x-ray scattering/diffraction, where strains are simultaneously measured in the macroscopic tissue, collagen fibrils and mineral. Compared to healthy bone, results show that the fibrillar strain is decreased by ~40% following 70 kGy exposures, consistent with significant stiffening and degradation of the collagen. We attribute the irradiation-­induced deterioration in mechanical properties to mechanisms at multiple length-scales, including changes in crack paths at micron-­scales, loss of plasticity from suppressed fibrillar sliding at sub-­micron scales, and the loss and damage of collagen at the nano-­scales, the latter being assessed using Raman and Fourier-Transform-Infrared spectroscopy and a fluorometric assay.

  14. Toward an organ based dose prescription method for the improved accuracy of murine dose in orthovoltage x-ray irradiators

    International Nuclear Information System (INIS)

    Belley, Matthew D.; Wang, Chu; Nguyen, Giao; Gunasingha, Rathnayaka; Chao, Nelson J.; Chen, Benny J.; Dewhirst, Mark W.; Yoshizumi, Terry T.

    2014-01-01

    Purpose: Accurate dosimetry is essential when irradiating mice to ensure that functional and molecular endpoints are well understood for the radiation dose delivered. Conventional methods of prescribing dose in mice involve the use of a single dose rate measurement and assume a uniform average dose throughout all organs of the entire mouse. Here, the authors report the individual average organ dose values for the irradiation of a 12, 23, and 33 g mouse on a 320 kVp x-ray irradiator and calculate the resulting error from using conventional dose prescription methods. Methods: Organ doses were simulated in the Geant4 application for tomographic emission toolkit using the MOBY mouse whole-body phantom. Dosimetry was performed for three beams utilizing filters A (1.65 mm Al), B (2.0 mm Al), and C (0.1 mm Cu + 2.5 mm Al), respectively. In addition, simulated x-ray spectra were validated with physical half-value layer measurements. Results: Average doses in soft-tissue organs were found to vary by as much as 23%–32% depending on the filter. Compared to filters A and B, filter C provided the hardest beam and had the lowest variation in soft-tissue average organ doses across all mouse sizes, with a difference of 23% for the median mouse size of 23 g. Conclusions: This work suggests a new dose prescription method in small animal dosimetry: it presents a departure from the conventional approach of assigninga single dose value for irradiation of mice to a more comprehensive approach of characterizing individual organ doses to minimize the error and uncertainty. In human radiation therapy, clinical treatment planning establishes the target dose as well as the dose distribution, however, this has generally not been done in small animal research. These results suggest that organ dose errors will be minimized by calibrating the dose rates for all filters, and using different dose rates for different organs

  15. 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.

  16. Saffron extracts effect on processes in brain structures under exposure to x-ray irradiation of medium dose

    International Nuclear Information System (INIS)

    Rzaeva, A.

    2012-01-01

    Full text : Process of ionizing radiation on live organism is accompanied by interaction of free radicals (FR) with molecules of proteins, nucleic acids and lipids. In its turn, FR occurs subsequently by excitation and ionization of molecules. Besides all, ionizing radiation becomes the reason of accumulation in body tissues of toxic products (radio toxic) that strengthen beam effect. Endogenous antioxidatic system (EAS) of an organism plays a significant role in detoxication of redundant quantity of FR formed in cells. Ionizing radiation influences negatively to high-grade functioning of basic EAS enzymes. Besides, during radiation injuries, the level of FR increases. In case of its exhaustion and lack insertion of natural antioxidants (bioantioxidants) to organism plays a therapeutic role. Thus, in our work we used saffron extract in experiments with the purpose of studying its effect on the activity of antioxidant enzymes at radiation influence. Determination of proteins has been carried out with Lowry method. In the result of carried-out researches, it has been detected fixed dynamics of activity change of antioxidant enzymes in various brain structures of white rats within x-ray irradiation at medium dose, and joint impact of x-ray radiation of saffron extract. Under exposure to X-ray irradiation of medium dose in some brain structures decreasing of catalase activity was revealed. Tendency towards decreasing is more developed on the 3th day of irradiation. As opposed to catalase activity GPO activity was increased. Insertion of saffron extract to experimental animals (for 21 days before irradiation) conducive to prevention the decreasing of catalase activity stabilizes GPO activity and exerts an effective influence. Thereby, bioantioxidants have significant role in the regulation of processes occurred in tissues and cells under the influence of extreme factors. Antioxidant protection system of organism carries out continuous protection of organism from toxic

  17. Late changes in lungs of rats irradiated with 6.5 Gy of X-rays

    International Nuclear Information System (INIS)

    Mazanowska, A.M.; Jelenska, M.M.; Dancewicz, A.M.

    1978-01-01

    1, 3, 6 and 9 months after exposure of mature male rats to 650 rads of X-rays, the composition of isolated lung collagen has been estimated and the distribution of fatty acids in lipids of lung wash analyzed. The results obtained indicate that during the development of lung fibrosis proportion of type I to type III collagen in this organ increases. At the same period increases proportion of saturated fatty acids in lipids isolated from lung wash. Thus, radiation-induced fibrosis is accompanied not only by collagen accumulation but also by an essential change in the type of collagen produced. It seems that also the increased saturation of fatty acids in lung surfactant contributes to the impairment of function of fibrotic lung. (orig./AJ) [de

  18. 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

  19. 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.

  20. 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.

  1. Mechanism of soft x-ray continuum radiation from low-energy pinch discharges of hydrogen and ultra-low field ignition of solid fuels

    Science.gov (United States)

    Mills, R.; Lotoski, J.; Lu, Y.

    2017-09-01

    EUV continuum radiation (10-30 nm) arising only from very low energy pulsed pinch gas discharges comprising some hydrogen was first observed at BlackLight Power, Inc. and reproduced at the Harvard Center for Astrophysics (CfA). The source was determined to be due to the transition of H to the lower-energy hydrogen or hydrino state H(1/4) whose emission matches that observed wherein alternative sources were eliminated. The identity of the catalyst that accepts 3 · 27.2 eV from the H to cause the H to H(1/4) transition was determined to HOH versus 3H. The mechanism was elucidated using different oxide-coated electrodes that were selective in forming HOH versus plasma forming metal atoms as well as from the intensity profile that was a mismatch for the multi-body reaction required during 3H catalysis. The HOH catalyst was further shown to give EUV radiation of the same nature by igniting a solid fuel comprising a source of H and HOH catalyst by passing a low voltage, high current through the fuel to produce explosive plasma. No chemical reaction can release such high-energy light. No high field existed to form highly ionized ions that could give radiation in this EUV region that persisted even without power input. This plasma source serves as strong evidence for the existence of the transition of H to hydrino H(1/4) by HOH as the catalyst and a corresponding new power source wherein initial extraordinarily brilliant light-emitting prototypes are already producing photovoltaic generated electrical power. The hydrino product of a catalyst reaction of atomic hydrogen was analyzed by multiple spectroscopic techniques. Moreover, the mH catalyst was identified to be active in astronomical sources such as the Sun, stars and interstellar medium wherein the characteristics of hydrino match those of the dark matter of the Universe.

  2. Thermoluminescence Response of Copper-Doped Potassium Borate Glass Subjected to 6 Megavolt X-Ray Irradiation

    Science.gov (United States)

    Hossain, I.; Shekaili, N. K.; Wagiran, H.

    2015-03-01

    This study addresses the characteristics of Cu-doped and undoped potassium borate glass for use as ionizing radiation dosimeters by investigating and comparing the thermoluminescence responses, linearity, sensitivity and dose response s of the two types of glasses. A number of samples based on xK 2 CO 3 + (100 - x)H 3 BO 3 , where 10 ≤ x ≤ 30 mol.%, have been prepared using a melt quenching technique. The amorphous phases were identified using X-ray diffraction (XRD). The undoped potassium borate samples 20K 2 CO 3 + 80H 3 BO 3 (mol.%) and Cu-doped (0.5 mol.%) samples were placed in a solid phantom apparatus and irradiated with in X-ray tube under 6 MV accelerating voltage with doses ranging from 0.5 to 4.0 Gy. This beam was produced by the Primus MLC 3339 linear accelerator (LINAC) available at Hospital Sultan Ismail, Johor Bahru, Malaysia. The results clearly show the superiority of Cu-doped glass in terms of response and sensitivity to producing luminescence over undoped potassium borate glass. The sensitivity of Cu-doped glass is 6.75 times greater than that of undoped glass.

  3. Study of the gamma emission from the 31-year isomer of 178Hf induced by X-ray irradiation

    International Nuclear Information System (INIS)

    Collins, C.B.; Davanloo, F.; Iosif, M.C.

    1999-01-01

    A sample containing 6.3x10 14 nuclei of the 16 + isomer of 178 Hf having a half-life of 31 years and excitation energy of 2.446 MeV was irradiated with x-ray pulses derived from a device operated at 15mA to produce Bremsstrahlung radiation with an end point energy set to be 90 keV. Gamma-spectra of the isomeric target were taken with a Ge-detector. Intensity of the 325.5 keV (6 + →4 + transition in the ground state band of 178 Hf was found to increase by about 2%. Such an accelerated decay of the 178 Hf isomer is consistent with an integrated cross section of 3x10 -23 cm 2 ·keV if the resonant absorption takes place within the energy ranges corresponding to the maxima of the x-ray flux, either near 20 keV, or at the K emission lines of W

  4. ROVIBRATIONALLY RESOLVED DIRECT PHOTODISSOCIATION THROUGH THE LYMAN AND WERNER TRANSITIONS OF H2 FOR FUV/X-RAY-IRRADIATED ENVIRONMENTS

    International Nuclear Information System (INIS)

    Gay, C. D.; Porter, R. L.; Stancil, P. C.; Abel, N. P.; Ferland, G. J.; Shaw, G.; Van Hoof, P. A. M.; Williams, R. J. R.

    2012-01-01

    Using ab initio potential curves and dipole transition moments, cross-section calculations were performed for the direct continuum photodissociation of H 2 through the B 1 Σ + u 1 Σ + g (Lyman) and C 1 Π u 1 Σ + g (Werner) transitions. Partial cross-sections were obtained for wavelengths from 100 Å to the dissociation threshold between the upper electronic state and each of the 301 bound rovibrational levels v''J'' within the ground electronic state. The resulting cross-sections are incorporated into three representative classes of interstellar gas models: diffuse clouds, photon-dominated regions, and X-ray-dominated regions (XDRs). The models, which used the CLOUDY plasma/molecular spectra simulation code, demonstrate that direct photodissociation is comparable to fluorescent dissociation (or spontaneous radiative dissociation, the Solomon process) as an H 2 destruction mechanism in intense far-ultraviolet or X-ray-irradiated gas. In particular, changes in H 2 rotational column densities are found to be as large as 20% in the XDR model with the inclusion of direct photodissociation. The photodestruction rate from some high-lying rovibrational levels can be enhanced by pumping from H Lyβ due to a wavelength coincidence with cross-section resonances resulting from quasi-bound levels of the upper electronic states. Given the relatively large size of the photodissociation data set, a strategy is described to create truncated, but reliable, cross-section data consistent with the wavelength resolving power of typical observations.

  5. Temperature-dependent surface modification of Ta due to high-flux, low-energy He+ ion irradiation

    International Nuclear Information System (INIS)

    Novakowski, T.J.; Tripathi, J.K.; Hassanein, A.

    2015-01-01

    This work examines the response of Tantalum (Ta) as a potential candidate for plasma-facing components (PFCs) in future nuclear fusion reactors. Tantalum samples were exposed to high-flux, low-energy He + ion irradiation at different temperatures in the range of 823–1223 K. The samples were irradiated at normal incidence with 100 eV He + ions at constant flux of 1.2 × 10 21 ions m −2  s −1 to a total fluence of 4.3 × 10 24 ions m −2 . An additional Ta sample was also irradiated at 1023 K using a higher ion fluence of 1.7 × 10 25 ions m −2 (at the same flux of 1.2 × 10 21 ions m −2  s −1 ), to confirm the possibility of fuzz formation at higher fluence. This higher fluence was chosen to roughly correspond to the lower fluence threshold of fuzz formation in Tungsten (W). Surface morphology was characterized with a combination of field-emission scanning electron microscopy (FE-SEM) and atomic force microscopy (AFM). These results demonstrate that the main mode of surface damage is pinholes with an average size of ∼70 nm 2 for all temperatures. However, significantly larger pinholes are observed at elevated temperatures (1123 and 1223 K) resulting from the agglomeration of smaller pinholes. Ex situ X-ray photoelectron spectroscopy (XPS) provides information about the oxidation characteristics of irradiated surfaces, showing minimal exfoliation of the irradiated Ta surface. Additionally, optical reflectivity measurements are performed to further characterize radiation damage on Ta samples, showing gradual reductions in the optical reflectivity as a function of temperature.

  6. Si(Li) X-ray detector

    International Nuclear Information System (INIS)

    Yuan Xianglin; Li Zhiyong; Hong Xiuse

    1990-08-01

    The fabrication technology of the 10∼80 mm 2 Si(Li) X-ray detectors are described and some problems concerning technology and measurement are discussed. The specifications of the detectors are shown as well. The Si(Li) X-ray detector is a kind of low energy X-ray detectors. Owing to very high energy resolution, fine linearity and high detection efficiency in the range of low energy X-rays, it is widely used in the fields of nuclear physics, medicine, geology and environmental protection, etc,. It is also a kernel component for the scanning electron microscope and X-ray fluorescence analysis systems

  7. Velocity-resolved [Ne III] from X-ray irradiated Sz 102 microjets

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Chun-Fan; Shang, Hsien [Institute of Astronomy and Astrophysics, Academia Sinica (ASIAA), P.O. Box 23-141, Taipei 10641, Taiwan (China); Walter, Frederick M. [Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY 11794-3800 (United States); Herczeg, Gregory J. [The Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871 (China)

    2014-05-10

    Neon emission lines are good indicators of high-excitation regions close to a young stellar system because of their high ionization potentials and large critical densities. We have discovered [Ne III] λ3869 emission from the microjets of Sz 102, a low-mass young star in Lupus III. Spectroastrometric analyses of two-dimensional [Ne III] spectra obtained from archival high-dispersion (R ≈ 33, 000) Very Large Telescope/UVES data suggest that the emission consists of two velocity components spatially separated by ∼0.''3, or a projected distance of ∼60 AU. The stronger redshifted component is centered at ∼ + 21 km s{sup –1} with a line width of ∼140 km s{sup –1}, and the weaker blueshifted component at ∼ – 90 km s{sup –1} with a line width of ∼190 km s{sup –1}. The two components trace velocity centroids of the known microjets and show large line widths that extend across the systemic velocity, suggesting their potential origins in wide-angle winds that may eventually collimate into jets. Optical line ratios indicate that the microjets are hot (T ≲ 1.6 × 10{sup 4} K) and ionized (n{sub e} ≳ 5.7 × 10{sup 4} cm{sup –3}). The blueshifted component has ∼13% higher temperature and ∼46% higher electron density than the redshifted counterpart, forming a system of an asymmetric pair of jets. The detection of the [Ne III] λ3869 line with the distinct velocity profile suggests that the emission originates in flows that may have been strongly ionized by deeply embedded hard X-ray sources, most likely generated by magnetic processes. The discovery of [Ne III] λ3869 emission along with other optical forbidden lines from Sz 102 supports the picture of wide-angle winds surrounding magnetic loops in the close vicinity of the young star. Future high-sensitivity X-ray imaging and high angular-resolution optical spectroscopy may help confirm the picture proposed.

  8. Velocity-resolved [Ne III] from X-ray irradiated Sz 102 microjets

    International Nuclear Information System (INIS)

    Liu, Chun-Fan; Shang, Hsien; Walter, Frederick M.; Herczeg, Gregory J.

    2014-01-01

    Neon emission lines are good indicators of high-excitation regions close to a young stellar system because of their high ionization potentials and large critical densities. We have discovered [Ne III] λ3869 emission from the microjets of Sz 102, a low-mass young star in Lupus III. Spectroastrometric analyses of two-dimensional [Ne III] spectra obtained from archival high-dispersion (R ≈ 33, 000) Very Large Telescope/UVES data suggest that the emission consists of two velocity components spatially separated by ∼0.''3, or a projected distance of ∼60 AU. The stronger redshifted component is centered at ∼ + 21 km s –1 with a line width of ∼140 km s –1 , and the weaker blueshifted component at ∼ – 90 km s –1 with a line width of ∼190 km s –1 . The two components trace velocity centroids of the known microjets and show large line widths that extend across the systemic velocity, suggesting their potential origins in wide-angle winds that may eventually collimate into jets. Optical line ratios indicate that the microjets are hot (T ≲ 1.6 × 10 4 K) and ionized (n e ≳ 5.7 × 10 4 cm –3 ). The blueshifted component has ∼13% higher temperature and ∼46% higher electron density than the redshifted counterpart, forming a system of an asymmetric pair of jets. The detection of the [Ne III] λ3869 line with the distinct velocity profile suggests that the emission originates in flows that may have been strongly ionized by deeply embedded hard X-ray sources, most likely generated by magnetic processes. The discovery of [Ne III] λ3869 emission along with other optical forbidden lines from Sz 102 supports the picture of wide-angle winds surrounding magnetic loops in the close vicinity of the young star. Future high-sensitivity X-ray imaging and high angular-resolution optical spectroscopy may help confirm the picture proposed.

  9. 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.

  10. Inhibitory effects of prior low-dose X-ray irradiation on carbon tetrachloride-induced hepatopathy in acatalasemic mice

    International Nuclear Information System (INIS)

    Yamaoka, Kiyonori; Kataoka, Takahiro; Taguchi, Takehito; Wang, Da-Hong; Mori, Shuji; Hanamoto, Katsumi; Kira, Shohei; Nomura, Takaharu

    2004-01-01

    The catalase activities in blood and organs of the acatalasemic (C3H/AnLCs b Cs b ) mouse of C3H strain are lower than those of the normal (C3H/AnLCs a Cs a ) mouse. We examined the effects of prior low-dose (0.5 Gy) X-ray irradiation, which reduced the oxidative damage under carbon tetrachloride-induced hepatopathy in the acatalasemic or normal mice. The acatalasemic mice showed a significantly lower catalase activity and a significantly higher glutathione peroxidase activity compared with those in the normal mice. Moreover, low-dose irradiation increased the catalase activity in the acatalasemic mouse liver to a level similar to that of the normal mouse liver. Pathological examinations and analyses of blood glutamic oxaloacetic and glutamic pyruvic transaminase activity and lipid peroxide levels showed that carbon tetrachloride induced hepatopathy was inhibited by low-dose irradiation. These findings may indicate that the free radical reaction induced by the lack of catalase and the administration of carbon tetrachloride is more properly neutralized by high glutathione peroxidase activity and low-dose irradiation in the acatalasemic mouse liver. (author)

  11. Analysis of fine structure of X-ray spectra from laser-irradiated gold dot

    International Nuclear Information System (INIS)

    Yang Guohong; Zhang Jiyan; Zhang Baohan; Zhou Yuqing; Li Jun

    2000-01-01

    The X-ray emission spectra from highly stripped plasma of gold has been observed by focusing a Nd-glass frequency tripled laser beam onto the surface of the gold dot at the XINGGUANG II laser facilities. The spectra of gold ions in the range of 0.0003 nm-0.0004 nm was recorded using the plate PET (2d = 0.8742 nm) crystal spectrometer. The code of average energy of relativistic sub-arrays was built on the basis of the code MCDF (Multi-Configuration-Dirac-Fock). Using the spin-orbit-split-arrays (SOSA) formalism, mean wavelengths and full widths at half height of isolated peaks of sub-arrays of lower charged gold ions, isoelectronic with Cu, Zn, Ga and Ge, was calculated. Twenty-six lines are interpreted, they pertain mainly to transitions of 3d-nf (n = 5,6,7) of gold ions from Ni-like to As-like. These results of experiment and calculation have important application in plasma diagnostics and examination of high Z elemental atomic structure calculation

  12. Bystander effects and compartmental stress response to X-ray irradiation in L929 cells.

    Science.gov (United States)

    Temelie, Mihaela; Stroe, Daniela; Petcu, Ileana; Mustaciosu, Cosmin; Moisoi, Nicoleta; Savu, Diana

    2016-08-01

    Bystander effects are indirect consequences of radiation and many other stress factors. They occur in cells that are not directly exposed to these factors, but receive signals from affected cells either by gap junctions or by molecules released in the medium. Characterizing these effects and deciphering the underlying mechanisms involved in radiation-induced bystander effects are relevant for cancer radiotherapy and radioprotection. At doses of X-ray radiation 0.5 and 1 Gy, we detected bystander effects as increased numbers of micronuclei shortly after the treatment, through medium transfer and by co-cultures. Interestingly, bystander cells did not exhibit long-term adverse changes in viability. Evaluation of several compartmental stress markers (CHOP, BiP, mtHsp60, cytHsp70) by qRT-PCR did not reveal expression changes at transcriptional level. We investigated the involvement of ROS and NO in this process by addition of specific scavengers of these molecules, DMSO or c-PTIO in the transferred medium. This approach proved that ROS but not NO is involved in the induction of lesions in the acceptor cells. These results indicate that L929 cells are susceptible to stress effects of radiation-induced bystander signaling.

  13. Influence of X-ray irradiation on metabolic effects of adrenaline

    Energy Technology Data Exchange (ETDEWEB)

    Szyszko, A [Wojskowy Instytut Higieny i Epidemiologii, Warsaw (Poland)

    1976-01-01

    Effects of 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, as 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 its effect was noted in either not irradiated mice or on the fourth day after irradiation.

  14. Investigation of the yield process by deformation luminescence of X-ray irradiated KCl:Ca2+

    International Nuclear Information System (INIS)

    Nakamura, S.; Ida, K.; Ohgaku, T.

    2011-01-01

    It is found that deformation luminescence gives us information about the microscopic yield process of X-ray irradiated KCl:Ca 2+ . The stress-strain curve has a macroscopic yield point. But we find that luminescence appears to start before the macroscopic yield. This means that dislocation begin to move before the macroscopic yield because deformation luminescence is attributed to radiation-induced dislocation motion. The beginning of luminescence is considered to be the microscopic yield. Investigating the dependence of microscopic yield stress on strain rate and impurity concentration gives us additional information. The activation volume obtained from the dependence of microscopic yield stress on strain rate is comparable to the value estimated from the concentration of impurity. Then the dislocation starts to move overcoming impurity-vacancy dipoles as obstacles to dislocation motion. The dislocation density starts to increase at the microscopic yield point and then sharply increases to the macroscopic yield.

  15. Application of the autoblood treated by preliminary extracorporeal X-ray irradiation in the therapy of bronchial asthma patients

    International Nuclear Information System (INIS)

    Goguev, N.T.

    1985-01-01

    A therapeutic method including extracorporeal x-ray irradiation of the autoblood of patients with bronchial asthma complicated by cortisone dependence and polyvalent drug intolerance, has been elaborated and clinically tested. The use of this method brings about good short-term results in 90% of cases and good long-term results in 40% of cases (14-38 months). It provides an opportunity to give up corticosteroids in more than 60% of patients and to decrease the hormone dose in the rest of cortisone-dependent patients with bronchial asthma. The above therapeutic method can be used as an independent type of treatment, especially in the presence of polyvalent drug allergy and as an element of multiple modality therapy of bronchial asthma patients. The method was used under in-patient conditions only. No side effects were marked in the course of the clinical trial. To carry out this type of therapy, patients should be thoroughly screened

  16. Influence of silver and copper doping on luminescent properties of zinc-phosphate glasses after x-ray irradiation

    Science.gov (United States)

    Murashov, Alexander A.; Sidorov, Alexander I.; Shakhverdov, Teimur A.; Stolyarchuk, Maxim V.

    2017-11-01

    It is shown, experimentally, that in silver- and copper-containing zinc-phosphate glasses, metal molecular clusters are formed during the glass synthesis. X-ray irradiation of these glasses led to the considerable increase of its luminescence in visible spectral range. This effect is caused by the transformation of the charged metal molecular clusters into the neutral state. Luminescence and excitation spectra of the glass, doped with silver and copper simultaneously, change significantly in comparison with the spectra of glasses doped with one metal. The reason for this can be the formation of hybrid AgnCum molecular clusters. The computer simulation of the structure and optical properties of such clusters by the time-dependent density functional theory method is presented. It is shown that the optimal luminescent material for photonics application, in comparison with other studied materials, is glass, containing hybrid molecular clusters.

  17. Effect of a low-dose x-ray irradiation on the development and differentiation of the cerebral cortex, (15)

    International Nuclear Information System (INIS)

    Hayashi, Yasushi; Hoshino, Kiyoshi; Hayasaka, Shizuka; Kameyama, Yoshiro

    1981-01-01

    Mice of 17 day's gestation received x-rays of 10 R, 25 R, or 100 R, and those of 13 or 15 day's gestation received 10 R in a single exposure. These irradiated fetuses were examined for the weight of the brain, thickness of the cerebral cortex, density of the cortical cells and branching of the pyramidal cells in the fifth layer of the cortex 12 weeks after birth. Decrease in the thickness of the cortex was observed in the mice which received 100 R at 17 day's gestation. A decrease in the branching index of the pyramidal cells was found in the mice which received 100 R. Although a decreasing tendency of the branching index was also recognized in those which received 10 R at 13 days of gestation, showing no statistically significant difference. (Ueda, J.)

  18. Radiation-induced defect-formation in lithium hydride and deuteride monocrystals. [Electron and X-ray irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Pustovarov, V.A.; Betenekova, T.A.; Zav' yalov, N.A.; Cholakh, S.O. (Ural' skij Politekhnicheskij Inst., Sverdlovsk (USSR))

    1983-08-01

    Methods of stationary and pulse absorption spectroscopy were used to investigate into processes of formation and decay of radiation defects in cubic LiH and LiD crystals. F- and V-centers form at low temperatures during crystal irradiation by photons, creating excitons selectively, accelerator electrons, X-ray radiation. Analysis of possible mechanisms of defect formation shows that radiation defect formation in LiH is based on radiationless exciton decay. It is shown that efficiency of F- and V-centers generation in pure and impure crystals in 80-298 K range is the same. Exciton decay with formation of Frenkel radiation defects in pure LiH and LiD crystals takes place, probably, in regular crystal lattice points. Process of radiation defect formation as a result of near activator exciton decay takes place in impure LiH-Na, LiD-Na crystals.

  19. Modifying action of DNA synthesis precursors on Aspergillus nidulans conidium irradiated by ultraviolet and X-rays

    International Nuclear Information System (INIS)

    Muronets, E.M.; Kameneva, S.V.

    1975-01-01

    Modification of inactivation action of radiation on conidia Aspergillus nidulans, UVS + and UVS strains, by desoxynucleosides, purine and pyrimidine bases is shown. The modification manifested in increased conidia survival is revealed when the precursor of DNA synthesis is added to the suspension before exposure to ultraviolet or X-rays. In the case of postradiation application of the substance no modification is observed. The modifying effect of different precursors becomes equally apparent with equimolar solutions and increases at higher concentration of the latter. An increase in thymidine endogenic pool in the exposed conidia does not affect their survival. When conidia are exposed to ultraviolet rays through a thymidine filter the survival rate increases to the same extent as in the case when they are exposed to irradiation in thymidine solution. The authors suggest that modification of the inactivating radiation action by DNA precursors at exposure of conidia Aspergillus nidulans is caused by the radioprotective effect of precursors not related to reparation [ru

  20. 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

  1. 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

  2. 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.

  3. Developmental abnormalities of the vitreous in mouse fetuses caused by simultaneous irradiation of x-rays and ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    Shirai, S; Yuguchi, S; Majima, A [Nagoya City Univ. (Japan). Faculty of Medicine

    1980-10-01

    Eye abnormalities in mouse fetuses caused by irradiation of X-rays alone, or simultaneous irradiation of X-rays and ultrasound on day 7 of gestation were histologically studied on day 18 of gestation. Developmental abnormalities of the vitreous were examined in the present experiment, and the following results were obtained. 1. Developmental abnormalities of the vitreous were observed in 23 fetuses, and unilateral cases were 15 of 23 fetuses. In 31 eyes with these abnormalities, much more abundant mesenchymal tissue of components of primary vitreous was found in the retrolental vitreous cavity than in the normal eyes. 2. The above 31 eyes were also accompanied by a variety of ocular abnormalities such as microphthalmia, faulty closure of the fetal fissure, aplasia and hypoplasia of the optic nerve, goniodysgenesis, and corneolenticular adhesion. Complications observed to be associated with developmental abnormalities of the vitreous were lens abnormalities, retinal traction and fold, fibrovascular anastomosis between mesenchymal tissues of the chamber angle and vitreous cavity, retinal rosette, and anomalies of the optic nerve head. 3. The histological findings of 17 eyes corresponded to anterior persistent hyperplastic primary vitreous (PHPV) encountered clinically, those of 3 eyes to posterior PHPV, those of 6 eyes to mixed type of both anterior and posterior types, and those of 5 eyes to PHPV of the optic nerve head. In 3 bilateral cases, the type was different for either eye. 4. From these results, it was considered that the pathogenesis of PHPV of Reese and congenital retinal fold of Mann consists of the maldevelopment of the components of the primary vitreous, and that the type of defect depends on the portion involved and the degree depends on the time at which the maldevelopment occurs.

  4. Developmental abnormalities of the optic nerve head in mouse fetuses caused by simultaneous irradiation of x-rays and ultrasound

    International Nuclear Information System (INIS)

    Shirai, Shoichiro; Yuguchi, Shuji; Majima, Akio.

    1981-01-01

    Eye abnormalities in mouse fetuses caused by irradiation of X-rays alone, or simultaneous irradiation of X-rays and ultrasound on day 7 of gestation were histologically studied on day 18 of gestation. Developmental abnormalities of the optic nerve head were examined in the present experiment, and the following results were obtained: 1. Developmental abnormalities of the optic nerve head associated with developmental abnormalities of the vitreous were detected in 4 fetuses (5 eyes). In all cases, excessive mesenchymal tissue of components of the primary vitreous was found from the optic nerve head to the vitreous cavity. It was impossible to distinguish between the neuroectodermal tissue of Bergmeister's papilla and the mesodermal tissue of components of the primary vitreous. 2. In 3 fetuses (4 eyes), the fetal fissure involving the optic nerve head was open. At the peripapillary region, the inner layer of the optic cup was everted and hyperplastic. The inner neuroblastic layer of the everted portion contacted the outer coat of the eyeball, directly. In these cases, the optic nerve entrance was very wide. 3. The relation between the congenital optic nerve head anomalies encountered clinically and those observed experimentally in the mouse fetuses was discussed. It was considered that the pathogenesis of congenital optic nerve head anomalies consists of the malformation of the primitive epithelial papilla, the faulty closure of the proximal end of the fetal fissure, the anomalies of Bergmeister's papilla, the anomalies of the hyaloid system, or the abnormal differentiation and growth of the neuroectodermal cells of the optic cup. (author)

  5. Developmental abnormalities of the vitreous in mouse fetuses caused by simultaneous irradiation of x-rays and ultrasound

    International Nuclear Information System (INIS)

    Shirai, Shoichiro; Yuguchi, Shuji; Majima, Akio

    1980-01-01

    Eye abnormalities in mouse fetuses caused by irradiation of X-rays alone, or simultaneous irradiation of X-rays and ultrasound on day 7 of gestation were histologically studied on day 18 of gestation. Developmental abnormalities of the vitreous were examined in the present experiment, and the following results were obtained. 1. Developmental abnormalities of the vitreous were observed in 23 fetused, and unilateral cases were 15 of 23 fetuses. In 31 eyes with these abnormalities, much more abundant mesenchymal tissue of components of primary vitreous was found in the retrolental vitreous cavity than in the normal eyes. 2. The above 31 eyes were also accompanied by a variety of ocular abnormalities such as microphthalmia, faulty closure of the fetal fissure, aplasia and hypoplasia of the optic nerve, goniodysgenesis, and corneolenticular adhesion. Complications observed to be associated with developmental abnormalities of the vitreous were lens abnormalities, retinal traction and fold, fibrovascular anastomosis between mesenchymal tissues of the chamber angle and vitrious cavity, retinal rosette, and anomalies of the optic nerve head. 3. The histological findings of 17 eyes corresponded to anterior persistent hyperplastic primary vitreous (PHPV) encountered clinically, those of 3 eyes to posterior PHPV, those of 6 eyes to mixed type of both anterior and posterior types, and those of 5 eyes to PHPV of the optic nerve head. In 3 bilateral cases, the type was different for either eye. 4. From these results, it was considered that the pathogenesis of PHPV of Reese and congenital retinal fold of Mann consists of the maldevelopment of the components of the primary vitreous, and that the type of defect is depends on the portion involved and the degree depends on the time at which the maldevelopment occurs. (author)

  6. A Study on the Effects of the X-Ray Irradiation and Thyroid Gland on the Erythropoietic System in Rabbit

    International Nuclear Information System (INIS)

    Kim, Kong Keun

    1967-01-01

    The effects of X-ray irradiation and the thyroid gland on the erythropoietic system were studied in the white male rabbits. The total body irradiation was done in doses of 250r and 500r to each of 5 rabbits for 10 days. The factors were 220 KV, 10 mA, FLI/4 Cu+1 mmAl (HVL:2.0 mmCu) 50 cm F.S.D. The thyroid dysfunction was experimentally induced by giving 2 mg of thyroid tablets per kg body weight for 15 days in 5 rabbits for hyperthyroidism and by giving 1.5 mC of 131 I per kg body weight in another 5 rabbits for hypothyroidism. Fourteen healthy rabbits were used as control. The hematologic changes and ferrokinetic data obtained from 59 Fe and apparent half survival of the red blood cells obtained from 51 Cr were compared. Following were the results: A. X-ray irradiated group; 1) There were no significant changes in hematologic findings except for leucopenia. A slight decrease of red blood cells was observed in 500r irradiated animals. 2) The decrease in the iron turnover rates of the plasma and red blood cells as well as in the red cell renewal rate were found in both groups. A significant decrease of the red cell iron utilization rate was observed in the 500r irradiated animals. 3) The apparent half survival times of the red blood cells were slightly, in the 250r (12.1±0.80 days), and markedly shortened in the 500r irradiated animals (9.8±1.38 days), the normal being 14.0±1.6 days. 4) It appears, therefore, that the anemia caused by X-ray irradiation is due to the inhibition of hemopoietic function and the excess destruction of the red blood cells. B. 1) The slight increase of the red blood cell count and circulating blood volume with the normal serum iron level were observed in the hyperthyoid group, while the decrease of the red and white blood cell counts, hemoglobin and hematocrit values with a marked decrease of the serum iron level in the hypothyroid group. 2) A marked decrease of the plasma iron disappearance rate with increase of plasma iron turnover

  7. Effect of Ar9+ irradiation on Zr-1Nb-1Sn-0.1Fe alloy characterized by Grazing Incidence X-ray diffraction technique

    Science.gov (United States)

    Dutta, Argha; Das, Kalipada; Gayathri, N.; Menon, Ranjini; Nabhiraj, P. Y.; Mukherjee, Paramita

    2018-03-01

    The microstructural parameters such as domain size and microstrain have been estimated from Grazing Incidence X-ray Diffraction (GIXRD) data for Ar9+ irradiated Zr-1Nb-1Sn-0.1Fe sample as a function of dpa (dose). Detail studies using X-ray Diffraction Line Profile Analysis (XRDLPA) from GIXRD data has been carried out to characterize the microstructural parameters like domain size and microstrain. The reorientation of the grains due to effect of irradiation at high dpa (dose) has been qualitatively assessed by the texture parameter P(hkl).

  8. Dose-incidence relationships for exencephalia, anophthalmia and prenatal mortality in mouse embryos irradiated with fission neutrons or 250 kV X-rays

    Energy Technology Data Exchange (ETDEWEB)

    Friedberg, W.; Faulkner, D.N.; Neas, B.R.; Hanneman, G.D.; Darden, E.B. Jr.; Deal, R.B. Jr.; Parker, D.E.

    1987-08-01

    Groups of pregnant mice were irradiated at selected times between 10.00 hours on gestation day 7 and 16.00 hours on day 8. Each group received 0.39 Gy of neutrons or 1.60 Gy of X-rays, or was sham irradiated. We identified a period of high susceptibility of the embryos to radiation-induced exencephalia, anophthalmia and prenatal mortality early in gestation day 8. Dose-incidence relationships in this period were investigated with 0.19-0.48 Gy of neutrons and with 0.40-2.00 Gy of X-rays.

  9. Dose-incidence relationships for exencephalia, anophthalmia and prenatal mortality in mouse embryos irradiated with fission neutrons or 250 kV X-rays

    International Nuclear Information System (INIS)

    Friedberg, W.; Faulkner, D.N.; Neas, B.R.; Hanneman, G.D.; Deal, R.B. Jr.; Parker, D.E.

    1987-01-01

    Groups of pregnant mice were irradiated at selected times between 10.00 hours on gestation day 7 and 16.00 hours on day 8. Each group received 0.39 Gy of neutrons or 1.60 Gy of X-rays, or was sham irradiated. We identified a period of high susceptibility of the embryos to radiation-induced exencephalia, anophthalmia and prenatal mortality early in gestation day 8. Dose-incidence relationships in this period were investigated with 0.19-0.48 Gy of neutrons and with 0.40-2.00 Gy of X-rays. (author)

  10. Study of food intake dynamics in rats following acute whole-body irradiation with X rays

    International Nuclear Information System (INIS)

    Smajda, B.; Ahlers, I.; Datelinka, I.

    1987-01-01

    The effects were studied of whole-body X-irradiation with sublethal (2.39 Gy) and medium lethal (5.74 Gy) doses on food intake by rats. The lower dose caused a temporary decrease in food intake, with a minimum of 63.3% of the control level on the 2nd day after irradiation. The decrease was statistically significant up to the 4th day after irradiation. No substantial changes were observed in the parameters of the circadian rhythm in food intake with the maximum on the 3rd day after irradiation, with only 8% of the initial value. The food intake was reduced until the 9th day after irradiation. The daily thythm of food intake was strongly disturbed during the first three days after irradiation, then restoring gradually and on the 9th day showing the original phasing and shape. The results obtained were in agreement with the assumed neural regulation mechanism of food intake and its circadian rhythm in the rat. (author). 5 figs., 12 refs

  11. Preventive effect of ganoderma lucidum (Reishi) on the suppression of hematopoietic system by X-ray irradiation

    International Nuclear Information System (INIS)

    Itoh, Hiroko; Nakata, Fukuyoshi; Sasaki, Hiroyuki; Ito, Hitoshi

    2013-01-01

    Reishi has been used for a roborant or the elixir of life from ancient times. In the present study, the preventive effects of Reishi on hematopoietic suppression from X-ray irradiation in mice were investigated. 5.0 Gy-irradiated mice induced the decrease of red blood cell, platelet, white blood cell, granulocytes, the index of spleen and thymus, and the number of spleen cells. Oral administration of Reishi tended to decrease these damage on hematopoiesis, and reticuloendothelial system. Reishi enhanced the degree of spleen cells-mediated sheep red blood cells (SRBC) hemolysis (quantitative hemolysis of SRBC). Reishi augmented the level of erythroid burst-forming cell (BFU-E), and accelerated the recovery of the number of BFU-E in X-irradiated mice, although Reishi did not influence red blood cell counts and colony-forming unit-erythropoetin dependent (CFU-E) number. A significant elevation in the CFU-GM (granulocytes-macrophages) level was observed. Histological examinations revealed that Reishi accerelated the hematopoietic recovery and decrease on damage of spleen and thymus. (author)

  12. The nuclear pore density in rat liver cells upon regeneration and total body X-ray irradiation

    International Nuclear Information System (INIS)

    Kuz'mina, S.N.; Troitskaya, L.P.; Mirkhamidova, P.A.; Bul'dyaeva, T.V.; Zbarskij, I.B.; Grigor'ev, V.B.; Akademiya Meditsinskikh Nauk SSSR, Moscow. Inst. Virusologii)

    1979-01-01

    The nuclear pore density has been investigated in rat liver cells in the course of regeneration and X-ray irradiation. It has been found that the number of pore complexes (PC) per nuclear shell (NS) unit area in the liver cells is not constant. In an hour following whole-body irradiation of rats with a regenerating liver at the 1200 R dose the number of PC per 1 μm 2 of the nuclear shell area decreases by 5, 8 times as compared with the PC density in the regenerating liver cells of the irradiated rats, the PC degradation and structural rupture being observed. It has been established by means of the freezing-etching method which enables PC surfaces observation as for cytoplasma as well as for nucleoplasma that the PC peripheral granulas and the central granula consist of subparticles being approximately of the same size. The central granula forms a channel through which the material containing RNA passes from the nucleus to the cytoplasma. On the basis of the fact that the treatement by Triton X-100, disarranging the integrity of the NS membranous structure, preserves PC in relation to the fibrous layer as well as on the basis of the unequal nuclear pore state observed on the platinum-carbon replicas from nuclei splits it is supposed that PC can be formed in the nucleus and then in the course of repening ''built in'' PS

  13. Low-energy electron irradiation induced top-surface nanocrystallization of amorphous carbon film

    Science.gov (United States)

    Chen, Cheng; Fan, Xue; Diao, Dongfeng

    2016-10-01

    We report a low-energy electron irradiation method to nanocrystallize the top-surface of amorphous carbon film in electron cyclotron resonance plasma system. The nanostructure evolution of the carbon film as a function of electron irradiation density and time was examined by transmission electron microscope (TEM) and Raman spectroscopy. The results showed that the electron irradiation gave rise to the formation of sp2 nanocrystallites in the film top-surface within 4 nm thickness. The formation of sp2 nanocrystallite was ascribed to the inelastic electron scattering in the top-surface of carbon film. The frictional property of low-energy electron irradiated film was measured by a pin-on-disk tribometer. The sp2 nanocrystallized top-surface induced a lower friction coefficient than that of the original pure amorphous film. This method enables a convenient nanocrystallization of amorphous surface.

  14. Effect of continuous irradiation with low dose X-rays on the reproductive complications in male diabetic rats

    International Nuclear Information System (INIS)

    Zhao Hongguang; Xu Songbai; Li Pengwu; Wang Zhicheng; Lin Chenghe; Gong Shouliang

    2009-01-01

    Objective: To explore the effects of 75 mGy irradiation on the apoptosis of spermatogenic cells and antioxidant capacity of serum and testis and hormone levels in male rats with diabetes mellitus (DM). Methods: Rats were injected intraperitoneally with streptozotocin (STZ) to develop diabetes. The diabetic rats were irradiated with 75 mGy X-rays every other day for 4 weeks. Their survival rate and body weight were recorded 12 weeks after development of diabetes. The apeptosis percentage of germ cells was measured with flow cytometry and TUNEL method. The changes of anti-oxidation and gonadal hormone levels in serum and testis were measured with kits. Results: After the rats suffered from diabetes for 12 weeks, the survival rate in DM group was 25% (6/24), 100% in normal control group (16116). The survival rate in 75 mGy + DM group (9/16,56.25%) was obviously higher than that in the DM group (χ 2 = 4.00,P < 0.05). Meanwhile, the percentage of apaptotic spermatogenic cells in the diabetic rats was significantly larger than those in the normal control and irradiation groups (F = 5.496, P < 0.05). MDA and NO levels in serum and testis of diabetic rats were higher in varying degrees than that in the normal control, while the serum and testis MDA content in the 75 mGy + DM group were lower than those in the DM group especially in the testis (F = 10.644, P < 0.01). 75 mGy X-ray irradiation decreased NO content in the diabetic rats serum significantly (F = 14.379, P < 0.05) and increased NOS activity and TS, FSH level (F = 9.676, 43.194 and 5.282, respectively, P < 0.05 and P < 0.01). Conclusions: LDR could decrease the MDA level and NO content, and increase the antioxidant enzyme activity and TS and FSH levels in testis and serum of diabetic rats. (authors)

  15. 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.

  16. 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

  17. 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

  18. Age-related effects of X-ray irradiation on mouse hippocampus

    DEFF Research Database (Denmark)

    Casciati, Arianna; Dobos, Katalin; Antonelli, Francesca

    2016-01-01

    Therapeutic irradiation of pediatric and adult patients can profoundly affect adult neurogenesis, and cognitive impairment manifests as a deficit in hippocampal-dependent functions. Age plays a major role in susceptibility to radiation, and younger children are at higher risk of cognitive decay w...

  19. Naturally irradiated fluorite as a historic violet pigment: Raman spectroscopic and X-ray diffraction study

    Czech Academy of Sciences Publication Activity Database

    Čermáková, Zdeňka; Bezdička, Petr; Němec, I.; Hradilová, J.; Šrein, V.; Blažek, Jan; Hradil, David

    2015-01-01

    Roč. 46, č. 2 (2015), s. 236-243 ISSN 0377-0486 R&D Projects: GA ČR GAP103/12/2211 Institutional support: RVO:61388980 ; RVO:67985556 Keywords : fluorite * pigment * fluorescence bands * diffraction lines broadening * irradiation Subject RIV: CA - Inorganic Chemistry Impact factor: 2.395, year: 2015

  20. Chromosomes and irradiation: in vitro study of the action of X-rays on human lymphocytes

    International Nuclear Information System (INIS)

    Mouriquand, C.; Patet, J.; Gilly, C.; Wolff, C.

    1966-01-01

    Radioinduced chromosomal aberrations were studied in vitro on leukocytes of human peripheral blood after x irradiation at 25, 50, 100, 200, and 300 R. The numeric and structural anomalies were examined on 600 karyotypes. The relationship between these disorders and the dose delivered to the blood are discussed. An explanation on their mechanism of formation is tentatively given. (authors) [fr

  1. 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.

  2. The functional state of perfused liver tissue in X-ray irradiated rats

    International Nuclear Information System (INIS)

    Borovikova, G.V.; Dokshina, G.A.; Lapteva, T.A.

    1981-01-01

    The results of studying the functional state of perfused liver tissue isolated from rates after irradiation in the 18.06x10 - 2 Kl/kg dose, which has been estimated by transamination process rate catalized alanine-(KF 2.6x1.2, ALT and aspartate by aminotransferases (KF 2.6x1.1, ACT), gluconeogenesis and urea production intensity presented. When comparing the results obtained on the perfused liver deprived of homeostatic body effects it has been found that the liver isolated from the body for the first 24 hours of the radiation sickness development possesses a higher radiation activity which manifests itself in intensification of the processes of gluconeogenesis and transamination with substrate addition. The third 24 hours upon irradiation in the isolated liver the intensity of the gluconeogenesis and transamination processes is attenuated

  3. Functional state of perfused liver tissue in X-ray irradiated rats

    Energy Technology Data Exchange (ETDEWEB)

    Borovikova, G.V.; Dokshina, G.A.; Lapteva, T.A. (Tomskij Gosudarstvennyj Univ. (USSR). Nauchno-Issledovatel' skij Inst. Biologii i Biofiziki)

    1981-01-01

    The results of studying the functional state of perfused liver tissue isolated from rats after irradiation in the 18.06x10/sup -2/ Kl/kg dose, which has been estimated by transamination process rate catalized alanine-(KF 2.6x1.2, ALT and aspartate by aminotransferases (KF 2.6x1.1, ACT), gluconeogenesis and urea production intensity presented. When comparing the results obtained on the perfused liver deprived of homeostatic body effects it has been found that the liver isolated from the body for the first 24 hours of the radiation sickness development possesses a higher radiation activity which manifests itself in intensification of the processes of gluconeogenesis and transamination with substrate addition. The third 24 hours upon irradiation in the isolated liver the intensity of the gluconeogenesis and transamination processes is attenuated.

  4. Pathological studies on carcinoma of the lung in rats induced by external x-ray irradiation

    International Nuclear Information System (INIS)

    Kodama, Tetsuro

    1978-01-01

    Lung tumors in Wistar rats were induced by administration of various doses of external irradiation through the anterior chest wall. Pulmonary fibrosis following external irradiation was observed in 13 of 17 rats (76.4%) in Group I (800R/day for 5 days), in 26 of 36 rats (78.8%) in Group II (800R/WK for 5 WKs), and in 6 of 18 rats (35.3%) in Group III (500R/WK for 4 WKs). The degree of pulmonary fibrosis was greater each time in the rats given 4,000R than in the rats given 2,000R. In Groups I and II 5 pulmonary tumors (2 squamous cell carcinomas, 1 adenocarcinoma, and 2 adenomas) were observed in 3 of 16 rats (17.6%), and 10 pulmonary tumors (4 squamous cell carcinomas, 1 adenocarcinoma, 4 adenomas, and 1 fibrosarcoma) were observed in 9 of 33 rats (24.2%), respectively. In Group III only 1 case of pulmonary adenoma was observed among 17 rats (6.8%). The first case of epithelial tumor of the lung was found in a rat in Group I. Histological findings during the course of the experiment revealed that the earliest changes following irradiation were those of radiation pneuminitis, characterized by engorged capillaries and edema in collapsed alveoli, with lymphocytic and plasma cell infiltrations. In addition, the nuclei of the lining cells of the alveoli and bronchioles were enlarged and atypical. From the 10th through the 20th experimental week, fibrosis of the alveolar septum and adenomatous hyperplasia of the alveolar lining became extensive, particularly in the bronchiolo-alveolar areas of the periphery of the lung. Atypical adenomatous hyperplasia occurred within the fibrotic lesion or in proximity to it. It was frequently followed by carcinoma, suggesting that carcinoma in the present experiment arose in atypical epithelium, induced by irradiation of the bronchiolo-alveolar epithelial lining

  5. Pathological studies on carcinoma of the lung in rats induced by external x-ray irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Kodama, T [Hiroshima Univ. (Japan). School of Medicine

    1978-08-01

    Lung tumors in Wistar rats were induced by administration of various doses of external irradiation through the anterior chest wall. Pulmonary fibrosis following external irradiation was observed in 13 of 17 rats (76.4%) in Group I (800R/day for 5 days), in 26 of 36 rats (78.8%) in Group II (800R/WK for 5 WKs), and in 6 of 18 rats (35.3%) in Group III (500R/WK for 4 WKs). The degree of pulmonary fibrosis was greater each time in the rats given 4,000R than in the rats given 2,000R. In Groups I and II 5 pulmonary tumors (2 squamous cell carcinomas, 1 adenocarcinoma, and 2 adenomas) were observed in 3 of 16 rats (17.6%), and 10 pulmonary tumors (4 squamous cell carcinomas, 1 adenocarcinoma, 4 adenomas, and 1 fibrosarcoma) were observed in 9 of 33 rats (24.2%), respectively. In Group III only 1 case of pulmonary adenoma was observed among 17 rats (6.8%). The first case of epithelial tumor of the lung was found in a rat in Group I. Histological findings during the course of the experiment revealed that the earliest changes following irradiation were those of radiation pneuminitis, characterized by engorged capillaries and edema in collapsed alveoli, with lymphocytic and plasma cell infiltrations. In addition, the nuclei of the lining cells of the alveoli and bronchioles were enlarged and atypical. From the 10th through the 20th experimental week, fibrosis of the alveolar septum and adenomatous hyperplasia of the alveolar lining became extensive, particularly in the bronchiolo-alveolar areas of the periphery of the lung. Atypical adenomatous hyperplasia occurred within the fibrotic lesion or in proximity to it. It was frequently followed by carcinoma, suggesting that carcinoma in the present experiment arose in atypical epithelium, induced by irradiation of the bronchiolo-alveolar epithelial lining.

  6. Life-shortening and carcinogenesis in mice irradiated neonatally with x rays

    International Nuclear Information System (INIS)

    Sasaki, S.; Kasuga, T.

    1981-01-01

    The characteristics of life-shortening and carcinogenesis were investigated in x-irradiated neonatal B6WFr mice. Animals were irradiated with 24 hr after birth and allowed to complete their normal life span. Mean life span was shortened linearly with doses at a rate of 9.1% per 100 R for females and 9.8% for males. The spectrum of neoplastic diseases was apparently modulated by x irradiation, showing neonatal B6WFr mice to be highly susceptible to the induction of thymic lymphoma, liver tumor, and pituitary tumor. The dose-response relationship for thymice lymphoma could be described by a linear-quadratic model, and linearity could be rejected. Thymic lymphoma developed after a short latent period, resulting in death between 100 and 450 days of age. Liver and pituitary tumors increased with increasing dose up to 400 R and decreased thereafter. The latent period for liver tumor development was apparently shortened with increasing doses. Pituitary tumor developed in excess only in females after a long latent period

  7. Chemical protection against gastrointestinal radiation injury in mice by WR 2822, WR 2823, or WR 109342 after 4 MeV x ray or fission neutron irradiation

    International Nuclear Information System (INIS)

    Connor, A.M.; Sigdestad, C.P.

    1982-01-01

    Three compounds were tested for their radioprotective properties against the effects of 4 MeV X rays or fission neutron irradiation. The endpoints tested were lethality, intestinal crypt survival, and DNA synthesizing cellularity. Two of the compounds tested; S-2(4-aminobutylamino) ethylphosphorothioc acid (WR 2822) and the aminopentylamino derivative (WR 109342). All drugs were administered via intraperitoneal injections at their approximately maximum tolerated dose. WR 2822 was shown to have a slight protective effect against X rays and neutrons. The dose modification factor (DMF) for gastrointestinal death (LD/sub 50(6)/) was 1.23 for X rays and 1.51 for neutrons. The assay for intestinal crypt survival produced DMF's of 1.44 (X rays) and 1.4 (neutrons). WR 2823 also showed a protective action in these assays. The DMF for LD/sub 50(6)/ was 1.32 (X rays) and 1.42 (neutrons). WR 109342 was found to be extremely toxic and had no significant protective effects. All three drugs were more toxic and demonstrated less protection in most of these assays than the benchmark radioprotective agent WR 2721, although WR 2822 protected against lethal effects of fission neutrons almost as well as WR 2721. Both WR 2822 and WR 2823 produced greater protection in the crypt survival assays for fission neutron irradiation than WR 2721

  8. Effect of head irradiation with X-rays on neuroendocrine in male rats of hypothalamic arcuate nucleus lesions

    International Nuclear Information System (INIS)

    Gong Shouliang; Li Xiuyi; Wei Jun; Liu Shuzheng

    1992-01-01

    It has been demonstrated that neonatal administration of monosodium glutamine (MSG) results in clearly defined lesions of the hypothalamic arcuate nucleus. The present study showed that neuroendocrine function changed significantly in adulthood when baby rats were injected with MSG (4 mg/g BW, ip) 2 and 4 days after their birth. The serum LH, FSH, TSH and GH and serum and urine testosterone (TS) levels and pituitary cAMP content were lower in MSG treated rats than those of intact rats, but the serum PRL level increased significantly and the testicular cAMP content did not change. Forty eight hours after head irradiation with 10 Gy X-rays in the male rats treated with MSG, the serum LH, FSH, TSH and GH and serum and urine TS levels tended to decrease, while the serum PRL level tended to increase and the pituitary and testicular cAMP contents didn't change. The results suggest that the functional irregularity of neuroendocrine system in MSG treated rats with extensive lesions of hypothalamic arcuate nucleus were not so significant as those of intact rats in response to irradiation

  9. Microscopic and flow cytometric study of micronuclei in iododeoxyuridine labelled cells irradiated with soft X-rays

    International Nuclear Information System (INIS)

    Ludwikow, G.; Staalnacke, C.G.; Johanson, K.J.; Sundell-Bergman, S.; Richter, S.; Swedish Univ. of Agricultural Sciences, Uppsala; Uppsala Univ.

    1990-01-01

    Iododeoxyuridine labelled (IUdR(+)) and unlabelled (IUdR(-)) CHO cells irradiated with 2 Gy of soft X-rays showed only minor differences in the kinetics of micronuclei formation during the first 20 hours postirradiation period. Between 20 to 40 hours, the IUdR(-) cells showed approximately a constant number of micronuclei while the number of micronuclei in IUdR(+) cells was still increasing. The frequency of micronuclei was higher in IUdR(+) cells compared to IUdR(-) cells at 24 hours after irradiation with various doses up to 4.0 Gy. Dose modifying factors were found to be 1.3 (microscopic evaluation) and 1.8 (flow cytometric evaluation). Flow cytometry with use of two parameters, fluorescence from propidium iodide and light scattering, seems to be a good tool to estimate the frequency of micronuclei in CHO cells in the dose range up to about 4 Gy. At higher doses perturbation of the cell cycle and the appearance of dying cells will influence the results. (orig.)

  10. Changes in regional blood flow of normal and tumor tissues following hyperthermia and combined X-ray irradiation

    International Nuclear Information System (INIS)

    Suga, Kazuyoshi

    1986-01-01

    Hyperthermia and X-ray irradiation were given to Ehrlich tumors, which were induced in the ventrum of the right hind foot of ICR mice, and to the normal tissues. Their effects on regional blood flow were examined using Xe-133 local clearance method. Blood flow of the normal tissues remained unchanged by heating at 41 deg C for 30 minutes, and increased by heating at 43 deg C and 45 deg C for 30 minutes. On the contrary, blood flow of the tumors decreased with an increase in temperature. When hypertermia (43 deg C for 30 minutes) was combined with irradiation of 30 Gy, decrease in blood flow of the tumors was greater than the normal tissues at 24 hours. Blood flow of the tumors depended on tumor size. The decreased amount of blood flow by hyperthermia was more for tumors > 250 mm 3 than tumors 3 . Blood flow ratios of tumor to normal tissues were also smaller in tumors > 250 mm 3 than tumors 3 . In the case of tumors 3 , blood flow tended to return to normal at 3 hr after heating at 43 deg C for 30 min. However, this was not seen in tumors > 250 mm 3 . (Namekawa, K.)

  11. 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)

  12. 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.

  13. 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.

  14. 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)

  15. 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

  16. Sci-Thur AM: YIS – 07: Optimizing dual-energy x-ray parameters using a single filter for both high and low-energy images to enhance soft-tissue imaging

    Energy Technology Data Exchange (ETDEWEB)

    Bowman, Wesley; Sattarivand, Mike [Department of Radiation Oncology, Dalhousie University at Nova Scotia Health Authority, Department of Radiation Oncology, Dalhousie University at Nova Scotia Health Authority (Canada)

    2016-08-15

    Objective: To optimize dual-energy parameters of ExacTrac stereoscopic x-ray imaging system for lung SBRT patients Methods: Simulated spectra and a lung phantom were used to optimize filter material, thickness, kVps, and weighting factors to obtain bone subtracted dual-energy images. Spektr simulations were used to identify material in the atomic number (Z) range [3–83] based on a metric defined to separate spectrums of high and low energies. Both energies used the same filter due to time constraints of image acquisition in lung SBRT imaging. A lung phantom containing bone, soft tissue, and a tumor mimicking material was imaged with filter thicknesses range [0–1] mm and kVp range [60–140]. A cost function based on contrast-to-noise-ratio of bone, soft tissue, and tumor, as well as image noise content, was defined to optimize filter thickness and kVp. Using the optimized parameters, dual-energy images of anthropomorphic Rando phantom were acquired and evaluated for bone subtraction. Imaging dose was measured with dual-energy technique using tin filtering. Results: Tin was the material of choice providing the best energy separation, non-toxicity, and non-reactiveness. The best soft-tissue-only image in the lung phantom was obtained using 0.3 mm tin and [140, 80] kVp pair. Dual-energy images of the Rando phantom had noticeable bone elimination when compared to no filtration. Dose was lower with tin filtering compared to no filtration. Conclusions: Dual-energy soft-tissue imaging is feasible using ExacTrac stereoscopic imaging system utilizing a single tin filter for both high and low energies and optimized acquisition parameters.

  17. Sci-Thur AM: YIS – 07: Optimizing dual-energy x-ray parameters using a single filter for both high and low-energy images to enhance soft-tissue imaging

    International Nuclear Information System (INIS)

    Bowman, Wesley; Sattarivand, Mike

    2016-01-01

    Objective: To optimize dual-energy parameters of ExacTrac stereoscopic x-ray imaging system for lung SBRT patients Methods: Simulated spectra and a lung phantom were used to optimize filter material, thickness, kVps, and weighting factors to obtain bone subtracted dual-energy images. Spektr simulations were used to identify material in the atomic number (Z) range [3–83] based on a metric defined to separate spectrums of high and low energies. Both energies used the same filter due to time constraints of image acquisition in lung SBRT imaging. A lung phantom containing bone, soft tissue, and a tumor mimicking material was imaged with filter thicknesses range [0–1] mm and kVp range [60–140]. A cost function based on contrast-to-noise-ratio of bone, soft tissue, and tumor, as well as image noise content, was defined to optimize filter thickness and kVp. Using the optimized parameters, dual-energy images of anthropomorphic Rando phantom were acquired and evaluated for bone subtraction. Imaging dose was measured with dual-energy technique using tin filtering. Results: Tin was the material of choice providing the best energy separation, non-toxicity, and non-reactiveness. The best soft-tissue-only image in the lung phantom was obtained using 0.3 mm tin and [140, 80] kVp pair. Dual-energy images of the Rando phantom had noticeable bone elimination when compared to no filtration. Dose was lower with tin filtering compared to no filtration. Conclusions: Dual-energy soft-tissue imaging is feasible using ExacTrac stereoscopic imaging system utilizing a single tin filter for both high and low energies and optimized acquisition parameters.

  18. MOX fuel irradiation behaviour: Results from X-ray microbeam analysis

    International Nuclear Information System (INIS)

    Walker, C.T.; Goll, W.; Matsumura, T.

    1997-01-01

    The behaviour of plutonium, xenon and caesium were investigated in two sections of irradiated MOX fuel produced by the OCOM process. In one fuel (OCOM30), the MOX agglomerates contained 18 wt% fissile plutonium, and had a low volume fraction of 0.17; in the other (OCOM15) the agglomerates contained 9 wt% fissile plutonium, and had a high volume fraction of 0.34. Both fuels had been irradiated under normal power reactor conditions to a burn-up of approximately 44 GWd/t. The main aim of the work was to establish whether the above differences in composition affected the percentage fission gas released by the fuels. Since U/Pu interdiffusion did not occurred during the irradiation, both fuels remained inhomogeneous on the microscopic scale. However, the concentration of plutonium in the MOX agglomerates decreases by about 50% as a result of fission, whereas the plutonium content of the UO 2 matrix increased by about a factor of four to approximately 2 wt% due to neutron capture by 238 U. The agglomerates in the OCOM15 fuel generally exhibited a finer structure due to the lower burn-up. More than 80% of the fission gas had been released from the oxide lattice of the MOX agglomerates in both fuels. However, a very high fraction of this gas precipitated and remained in the pore structure of the agglomerates. Consequently, puncturing revealed that for both fuels the percentage of gas released to the rod free volume increased from less than 0.5% at 10 GWd/t to a maximum of 3.5% at 45 GWd/t. The conclusion is that the percentage of gas released by MOX fuel is largely unaffected of the level of inhomogeneity of the fuel. In both fuels caesium showed near complete retention in both the MOX agglomerates and the UO 2 matrix. (author). 8 refs, 11 figs, 3 tabs

  19. Yellow hilum color mutants induced by X-ray irradiation in the soybean variety Fukuyutaka

    International Nuclear Information System (INIS)

    Takagi, Y.; Nakamura, D.; Yokoo, H.; Kishikawa, H.

    1990-01-01

    A total of 33 000 seeds with a light brown hilum were X-irradiated with 20 and 24 kr in 1982 and 1983, respectively. Seven yellow hilum mutants were selected from the M 2 (3 in 1983 and 4 in 1984) and compared for yield components and 2 quality traits with the original variety Fukuyutaka. Line 85-1 was selected from the M 6 in 1987. It was similar to Fukuyutaka for all characters and showed better tofu quality with regard to appearance and lustre. It was recommended for release under the name Murayutaka in 1988

  20. Skull x-ray

    Science.gov (United States)

    X-ray - head; X-ray - skull; Skull radiography; Head x-ray ... There is low radiation exposure. X-rays are monitored and regulated to provide the minimum amount of radiation exposure needed to produce the image. Most ...

  1. Neck x-ray

    Science.gov (United States)

    X-ray - neck; Cervical spine x-ray; Lateral neck x-ray ... There is low radiation exposure. X-rays are monitored so that the lowest amount of radiation is used to produce the image. Pregnant women and ...

  2. Low energy ion implantation and high energy heavy ion irradiation in C60 films

    International Nuclear Information System (INIS)

    Narayanan, K.L.; Yamaguchi, M.; Dharmarasu, N.; Kojima, N.; Kanjilal, D.

    2001-01-01

    C 60 films have been bombarded with low energy boron ions and high energy swift heavy ions (SHI) of silver and oxygen at different doses. Raman scattering and Fourier transform infrared (FTIR) studies were carried out on the virgin and irradiated films and the results are in good agreement with each other. The films subject to low energy boron ion implantation showed destruction of the bukky balls whereas the films subject to high energy ion irradiation did not show appreciable effects on their structure. These results indicate that C 60 films are more prone to defects by elastic collision and subsequent implantation at lower energy. Irradiation at higher energy was less effective in creating appreciable defects through electronic excitation by inelastic collisions at similar energy density

  3. Establishment of a primary standard system for low energy X-rays using a free air ionization chamber; Estabelecimento de um sistema padrao primario para raios-X de energias baixas com uma camara de ionizacao de ar livre

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Natalia Fiorini da

    2016-08-01

    In this work a primary standard system was established for low energy X-rays (10 kV to 50 kV), using a free air ionization chamber with concentric cylinders, Victoreen (Model 481-5), at the Calibration Laboratory of Instruments (LCI) of the Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP). For this, a new ionization chamber alignment protocol was developed for the radiation system and a modification on the micrometer housing used for the movement of the internal cylinders was ma de. The results obtained for the stability and characterization tests showed to be within the limits established by the standards IEC 61674 and IEC 60731. The correction factors for photon attenuation in the air, transmission and scattering in the diaphragm, scattering and fluorescence and ion recombination were also determined. These values were compared with those obtained by the German primary standard laboratory, Physikalisch-Technische Bundesanstalt (PTB), showing good agreement. Finally, the absolute values of the quantity air kerma rate for the standard qualities direct beams MWV28 and WMV35 and the attenuated beams WMH28 and WMH35 were determined; the results are in agreement, with a maximum difference of 3,8% with the values obtained using the secondary standard system of LCI. (author)

  4. Gas bubble network formation in irradiated beryllium pebbles monitored by X-Ray micro-tomography

    Energy Technology Data Exchange (ETDEWEB)

    Bolier, E; Ferrero, C. [Forschungszentrum Karlsruhe, Zimer 203, Gebaeude 451, Abteilung HVT-TL (Germany); Moslang, A. [Forschungszentrum Karlsruhe GmbH, FZK, Karlsruhe (Germany); Pieritz, R.A. [CNRS, Lab. de Glaciologie et Geophysique de l' Environnement, 38 - Saint Martin d' Heres (France)

    2007-07-01

    Full text of publication follows: The efficient and safe operation of helium cooled ceramic breeder blankets requires among others an efficient tritium release during operation at blanket relevant temperatures. In the past out-of-pile thermal desorption studies on low temperature neutron irradiated beryllium have shown that tritium and helium release peaks occur together. This phenomenon can be interpreted in terms of growth and coalescence of helium bubbles and tritium that either is trapped inside the helium bubbles in form of T{sub 2} molecules or in their strain field. With increasing temperature the bubble density and size at grain interfaces increase together with the probability of interconnected porosities and channel formation to the outer surface, leading to simultaneous helium and tritium release peaks in TDS. For a reliable prediction of gas release up to end-of-life conditions at blanket relevant temperatures, knowledge of the dynamics of bubble growth and coalescence as well as the 3D distribution of bubble network formation is indispensable. Such data could also be used to experimentally validate any future model predictions of tritium and helium release rates. A high resolution computer aided micro-tomography (CMT) setup has been developed at the European Synchrotron Radiation Facility which allowed reconstructing 3-D images of beryllium pebbles without damaging them. By postprocessing the data a 3D rendering of inner surfaces and of interconnected channel networks can be obtained, thus allowing the identification of open porosities in neutron irradiated and tempered beryllium pebbles. In our case Beryllium pebbles of 2 mm diameter had been neutron irradiated in the 'Beryllium' experiment at 770 K with 1.24 x 10{sup 25} nxm{sup -2} resulting in 480 appm He and 12 appm Tritium. After annealing at 1500 K CMT was performed on the pebbles with 4.9 and 1.4 {mu}m voxel resolution, respectively, followed by morphological and topological post

  5. Structural shielding at irradiation tests with x-rays up to 400 kV

    International Nuclear Information System (INIS)

    Rabitsch, H.; Schachinger, E.

    1979-12-01

    Tables worked out in accordance to the dimensioning method following DIN 54113 are given for the determination protective barriers thicknesses against effective and stray radiation in practical operation conditions. The tables comprise irradiation operation with directional and non-directional radiation sources radiators beams collimated and are restricted to steel as dispersive material for the barrier thicknesses against stray radiation. The calculations of protective barriers against stray radiation show that operation with properly chosen primary beam limiting orifice yields in considerable savings in protective shield thickness when compared to operation without or with mismatched orifice to film size. It further shows a relative indifference against changes of the stray area (film size) or the focus - film sheet distance. The protective shield thickness for the most common exposure conditions calculated according to the Austrian Regulations for Radiation Protection are on the safe side when compared to protective barriere thicknesses calculated according to DIN 54113. (V.M.)

  6. Experimental study on carcinoma of the stomach in rats induced by administration of N-methyl-N'-nitro-N-nitrosoguanidine and x-ray irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Haizuka, S [Hiroshima Univ. (Japan).School of Medicine

    1979-12-01

    Induction of gastrointestinal cancer in 109 6-week-old wistar rats (54 males, 55 fem