Sample records for radiation induced crystallinity

  1. Tyrosine/Cysteine Cluster Sensitizing Human ?D-Crystallin to Ultraviolet Radiation-Induced Photoaggregation in Vitro

    E-print Network

    Schafheimer, Steven Nathaniel

    Ultraviolet radiation (UVR) exposure is a major risk factor for age-related cataract, a protein-aggregation disease of the human lens often involving the major proteins of the lens, the crystallins. ?D-Crystallin (H?D-Crys) ...

  2. The radiation-induced crystalline-to-amorphous transition in zircon

    SciTech Connect

    Weber, W.J. (Materials Sciences Department, Pacific Northwest Laboratory, P.O. Box 999, Richland, Washington 99352 (United States)); Ewing, R.C.; Wang, L. (Department of Earth and Planetary Sciences, University of New Mexico, Albuquerque, New Mexico 87131 (United States))

    1994-03-01

    A comprehensive understanding of radiation effects in zircon, ZrSiO[sub 4], over a broad range of time scales (0.5 h to 570 million years) has been obtained by a study of natural zircon, Pu-doped zircon, and ion-beam irradiated zircon. Radiation damage in zircon results in the simultaneous accumulation of both point defects and amorphous regions. The amorphization process is consistent with models based on the multiple overlap of particle tracks, suggesting that amorphization occurs as a result of a critical defect concentration. The amorphization dose increases with temperature in two stages (below 300 K and above 473 K) and is nearly independent of the damage source ([alpha]-decay events or heavy-ion beams) at 300 K. Recrystallization of completely amorphous zircon occurs above 1300 K and is a two-step process that involves the initial formation of pseudo-cubic ZrO[sub 2].

  3. Tyrosine/Cysteine Cluster Sensitizing Human ?D-Crystallin to Ultraviolet Radiation-Induced Photoaggregation in Vitro

    PubMed Central

    2015-01-01

    Ultraviolet radiation (UVR) exposure is a major risk factor for age-related cataract, a protein-aggregation disease of the human lens often involving the major proteins of the lens, the crystallins. ?D-Crystallin (H?D-Crys) is abundant in the nucleus of the human lens, and its folding and aggregation have been extensively studied. Previous work showed that H?D-Crys photoaggregates in vitro upon exposure to UVA/UVB light and that its conserved tryptophans are not required for aggregation. Surprisingly, the tryptophan residues play a photoprotective role because of a distinctive energy-transfer mechanism. H?D-Crys also contains 14 tyrosine residues, 12 of which are organized as six pairs. We investigated the role of the tyrosines of H?D-Crys by replacing pairs with alanines and monitoring photoaggregation using light scattering and SDS-PAGE. Mutating both tyrosines in the Y16/Y28 pair to alanine slowed the formation of light-scattering aggregates. Further mutant studies implicated Y16 as important for photoaggregation. Mass spectrometry revealed that C18, in contact with Y16, is heavily oxidized during UVR exposure. Analysis of multiple mutant proteins by mass spectrometry suggested that Y16 and C18 likely participate in the same photochemical process. The data suggest an initial photoaggregation pathway for H?D-Crys in which excited-state Y16 interacts with C18, initiating radical polymerization. PMID:24410332

  4. High pulse repetition frequency ultrasound system for ex vivo measurement of mechanical properties of crystalline lenses with laser-induced microbubble interrogated by acoustic radiation force

    PubMed Central

    Yoon, Sangpil; Aglyamov, Salavat; Karpiouk, Andrei; Emelianov, Stanislav

    2012-01-01

    A high pulse repetition frequency ultrasound system for ex vivo measurement of mechanical properties of animal crystalline lens was developed and validated. We measured the bulk displacement of laser-induced microbubbles created at different positions within the lens using nanosecond laser pulses. An impulsive acoustic radiation force was applied to the microbubble, and spatio-temporal measurements of the microbubble displacement were assessed using a custom-made high pulse repetition frequency ultrasound system consisting of two 25 MHz focused ultrasound transducers. One of these transducers was used to emit a train of ultrasound pulses and another transducer was used to receive the ultrasound echoes reflected from the microbubble. The developed system was operating at 1 MHz pulse repetition frequency. Based on measured motion of the microbubble, the Young’s moduli of surrounding tissue were reconstructed and the values were compared with those measured using indentation test. Measured values of Young’s moduli of 4 bovine lenses ranged from 2.6±0.1 to 26±1.4 kPa and there was good agreement between the two methods. Therefore, our studies, utilizing the high pulse repetition frequency ultrasound system, suggest that the developed approach can be used to assess the mechanical properties of ex vivo crystalline lenses. Furthermore, the potential of the presented approach for in vivo measurements is discussed. PMID:22797709

  5. UV-radiation Induced Disruption of Dry-Cavities in Human ?D-crystallin Results in Decreased Stability and Faster Unfolding

    E-print Network

    Xia, Zhen

    Age-onset cataracts are believed to be expedited by the accumulation of UV-damaged human ?D-crystallins in the eye lens. Here we show with molecular dynamics simulations that the stability of ?D-crystallin is greatly reduced ...

  6. The influence of crystallinity on radiation stability of UHMWPE

    NASA Astrophysics Data System (ADS)

    Kornacka, Ewa Maria; Przybytniak, Gra?yna; ?wi?szkowski, Wojciech

    2013-03-01

    The influence of ionizing radiation on ultra high molecular weight polyethylene (UHMWPE) was studied using EPR spectroscopy and GC. Two samples of various degree of crystallinity, 85% and 53%, were investigated upon exposure to electron beam. In this study it was found that radicals generated following irradiation decay much faster in amorphous than in crystalline phase. The primary product generated in both phases is second ordered alkyl radical. EPR spectra detected for the sample containing 85% crystalline regions revealed a quintet of hyperfine splitting about 2.28 mT and the signal was tentatively assigned to the product of ?-fragmentation. The radiation yield of hydrogen for two studied samples of various crystallinity was similar.

  7. Inducing magnetism onto the surface of a topological crystalline insulator

    E-print Network

    Assaf, B. A.

    Inducing magnetism onto a topological crystalline insulator (TCI) has been predicted to result in several novel quantum electromagnetic effects. This is a consequence of the highly strain-sensitive band topology of such ...

  8. The radiation damage of crystalline silicon PN diode in tritium beta-voltaic battery.

    PubMed

    Lei, Yisong; Yang, Yuqing; Liu, Yebing; Li, Hao; Wang, Guanquan; Hu, Rui; Xiong, Xiaoling; Luo, Shunzhong

    2014-08-01

    A tritium beta-voltaic battery using a crystalline silicon convertor composed of (100)Si/SiO2/Si3N4 film degrades remarkably with radiation from a high intensity titanium tritide film. Simulation and experiments were carried out to investigate the main factor causing the degradation. The radiation damages mainly comes from the x-ray emitted from the titanium tritide film and beta particle can relieve the damages. The x-ray radiation induced positive charges in the SiO2 film destroying the output property of the PN diode with the induction of an electric field. PMID:24751350

  9. Boson induced nuclear fusion in crystalline solids

    Microsoft Academic Search

    P. Kálmán; T. Keszthelyi; D. Kis

    2010-01-01

    In a calculation of demonstrative type collective, laser-like behavior of low energy nuclear fusion reaction of deuterons in crystalline environment is investigated. It is found that the reported extra 4He production can be appropriately described with a model well known in quantum electronics in which the quantized boson (4He) field interacts with an ensemble of two-level systems in a crystal

  10. Growth Induced Magnetic Anisotropy in Crystalline and Amorphous Thin Films

    SciTech Connect

    Hellman, Frances

    1998-10-03

    OAK B204 Growth Induced Magnetic Anisotropy in Crystalline and Amorphous Thin Films. The work in the past 6 months has involved three areas of magnetic thin films: (1) amorphous rare earth-transition metal alloys, (2) epitaxial Co-Pt and hTi-Pt alloy thin films, and (3) collaborative work on heat capacity measurements of magnetic thin films, including nanoparticles and CMR materials.

  11. Combining optical coherence tomography with acoustic radiation force for depth-dependent biomechanics of crystalline lens

    NASA Astrophysics Data System (ADS)

    Wang, Shang; Aglyamov, Salavat; Karpiouk, Andrei; Li, Jiasong; Emelianov, Stanislav; Manns, Fabrice; Larin, Kirill V.

    2014-03-01

    Noninvasively probing the biomechanical properties of crystalline lens has been challenging due to its unique features such as location inside the eye and being optically and ultrasonically transparent. Here we introduce a method of relying on the spectral analysis of the lens surface response to a mechanical stimulation for the depthdependent assessment of lens biomechanical properties. In this method, acoustic radiation force (ARF) is used to remotely induce the deformation on the surface of the crystalline lens, and a phase-sensitive optical coherence tomography (PhS-OCT) system, co-focused with ARF, utilized to monitor the localized temporal response of ARFinduced deformations on the lens surface. The dominant frequency from the amplitude spectra of the surface response is obtained as the indicator of the depthwise elasticity distribution. Pilot experiments were performed on tissue-mimicking layered phantoms and ex vivo porcine crystalline lens. Results indicate that the frequency response of the sample surface is contributed by the mechanical properties of layers located at different depths and the depthdependent elastic properties can be revealed from the amplitude spectrum. Further study will be focused on combining the experimental measurements with theoretical model and inverse numerical method for depth-resolved elastography of the crystalline lens.

  12. Radiation-Induced Bioradicals

    NASA Astrophysics Data System (ADS)

    Lahorte, Philippe; Mondelaers, Wim

    This chapter represents the second part of a review in which the production and application of radiation-induced radicals in biological matter are discussed. In part one the general aspects of the four stages (physical, physicochemical, chemical and biological) of interaction of radiation with matter in general and biological matter in particular, were discussed. Here an overview is presented of modem technologies and theoretical methods available for studying these radiation effects. The relevance is highlighted of electron paramagnetic resonance spectroscopy and quantum chemical calculations with respect to obtaining structural information on bioradicals, and a survey is given of the research studies in this field. We also discuss some basic aspects of modem accelerator technologies which can be used for creating radicals and we conclude with an overview of applications of radiation processing in biology and related fields such as biomedical and environmental engineering, food technology, medicine and pharmacy.

  13. Gravitational radiation from crystalline color-superconducting hybrid stars

    E-print Network

    Bettina Knippel; Armen Sedrakian

    2009-04-17

    The interiors of high mass compact (neutron) stars may contain deconfined quark matter in a crystalline color superconducting (CCS) state. On a basis of microscopic nuclear and quark matter equations of states we explore the internal structure of such stars in general relativity. We find that their stable sequence harbors CCS quark cores with masses M_core \\le (0.78-0.82)M_{sun} and radii R_core \\le 7 km. The CCS quark matter can support nonaxisymmetric deformations, because of its finite shear modulus, and can generate gravitational radiation at twice the rotation frequency of the star. Assuming that the CCS core is maximally strained we compute the maximal quadrupole moment it can sustain. The characteristic strain of gravitational wave emission $h_0$ predicted by our models are compared to the upper limits obtained by the LIGO and GEO 600 detectors. The upper limits are consistent with the breaking strain of CCS matter \\sigma \\le 10^{-4} and large pairing gaps \\Delta \\sim 50 MeV, or, alternatively, with \\sigma \\sim 10^{-3} and small pairing gaps \\Delta \\sim 15 MeV. An observationally determined value of the characteristic strain h_0 can pin down the product \\sigma\\Delta^2. On the theoretical side a better understanding of the breaking strain of CCS matter will be needed to predict reliably the level of the deformation of CCS quark core from first principles.

  14. Gravitational radiation from crystalline color-superconducting hybrid stars

    E-print Network

    Knippel, Bettina

    2009-01-01

    The interiors of high mass compact (neutron) stars may contain deconfined quark matter in a crystalline color superconducting (CCS) state. On a basis of microscopic nuclear and quark matter equations of states we explore the internal structure of such stars in General Relativity. We find that their stable sequence harbors CCS quark cores with masses M_core \\le (0.78-0.82) M_solar and radii R_core \\le 7 km. The CCS quark matter can support non-axisymmetric deformations, because of its finite shear modulus, and can generate gravitational radiation at twice the rotation frequency of the star. Assuming that the CCS core is maximally strained we compute the maximal quadrupole moment it can sustain.The characteristic strain of gravitational wave emission h_0 predicted by our models are compared to the upper limits obtained by the LIGO and GEO 600 detectors. The upper limits are consistent with the breaking strain of CCS matter in the range sigma ~ 10^-3 and large pairing gaps Delta ~ 50 MeV, or, alternatively, with...

  15. Inducing magnetism onto the surface of a topological crystalline insulator

    NASA Astrophysics Data System (ADS)

    Assaf, B. A.; Katmis, F.; Wei, P.; Chang, Cui-Zu; Satpati, B.; Moodera, J. S.; Heiman, D.

    2015-05-01

    Inducing magnetism onto a topological crystalline insulator (TCI) has been predicted to result in several novel quantum electromagnetic effects. This is a consequence of the highly strain-sensitive band topology of such symmetry-protected systems. We thus show that placing the TCI surface of SnTe in proximity to EuS—a ferromagnetic insulator—induces magnetism at the interface between SnTe and EuS, and thus breaks time-reversal symmetry in the TCI. Magnetotransport experiments on SnTe-EuS-SnTe trilayer devices reveal a hysteretic lowering of the resistance at the TCI surface that coincides with an increase in the density of magnetic domain walls. This additional conduction could be a signature of topologically protected states within domain walls. Additionally, a hysteretic anomalous Hall effect reveals that the usual in-plane magnetic moment of the EuS layer is canted towards a perpendicular direction at the interface. These results are evidence of induced magnetism at the SnTe-EuS interfaces, resulting in broken time-reversal symmetry in the TCI.

  16. Inducing magnetism onto the surface of a topological crystalline insulator

    NASA Astrophysics Data System (ADS)

    Assaf, Badih A.; Katmis, Ferhat; Wei, Peng; Satpati, Biswarup; Moodera, Jagadeesh S.; Heiman, Don

    2015-03-01

    Magnetically-doped topological crystalline insulators (TCI) have been predicted to host a quantum anomalous Hall state characterized by a Chern number, as large a C =4. An alternative way to achieve this quantum state is by inducing magnetism onto the surface via magnetic proximity with a ferromagnetic insulator such as EuS. Similar to the proximity effect achieved in EuS/Bi2Se3 bilayers, we have induced magnetism onto the TCI SnTe in an MBE-grown SnTe/EuS/SnTe trilayer. Transport measurements at T =2K exhibit an anomalous Hall effect that is induced at the SnTe surfaces by the insulating ferromagnet EuS. The in-plane magnetoresistance (MR) exhibits a pronounced hysteresis that is isotropic with the direction of the applied magnetic field. Unlike the case of ferromagnetic semiconductors and metals, where the in-plane MR is highly anisotropic as a result of spin-scattering, the present MR is evidence of additional conduction inside the domain-walls at the EuS-SnTe interfaces. Further MR measurements in the minor loop regime confirm this effect. This work is a significant step to realizing exotic quantum states in TCI thin films. Supported by NSF-ECCS1402738, NSF-DMR-0907007, NSF-DMR-1207469, ONR-N000141310301, STC-CIQM-NSF-DMR-1231319.

  17. Radiation-induced angiosarcoma

    E-print Network

    Anzalone, C Lane; Cohen, Philip R; Diwan, Abdul H; Prieto, Victor G

    2013-01-01

    and radiation therapy, have largely supplanted radical mastectomy as the preferential treatment of breast cancer [cancer treatment has caused an increase, although still a rare side effect, in the numbers of cutaneous radiation-cancer has altered the average onset of the post-treatment angiosarcoma; radiation-

  18. The radiation destruction of crystalline polymers—I. The effect of radiation crosslinking on crystallinities of polyesters

    NASA Astrophysics Data System (ADS)

    Yiqun, Zhang; Danliang, Jin; Xinfang, Chen; Zhanchen, Chui; Yuxia, Luo; Hua, Li Shu

    1994-05-01

    Changes in crystallinity of crystalline polyethylene glycol terephthalate (PET) and polyhexamethylene terephthalate (PHT) irradiated by ?-ray (0-30 MGy) were investigated by means of a differential scanning calorimeter (DSC). The results of the first-run indicated that the melting point of both polyesters decreases with the increase of dose, and the half widths of melting peaks decrease at first and then increase with dose, that is there is a minimum half-width at some dose. The results of the second-run DSC indicate that the properties of recrystalline material are related to the crystal states in which the samples were irradiated. The entropies of fusion, ? S, were calculated from Tm and ? H. ? S decreases with dose increase for each polyester, and PHT, in which more crosslinking occurs, gives greater ? S than PET. The result is discussed from the point of view of crosslinking taking place within each crystal.

  19. Radiation-induced genomic instability

    NASA Technical Reports Server (NTRS)

    Kronenberg, A.

    1994-01-01

    Quantitative assessment of the heritable somatic effects of ionizing radiation exposures has relied upon the assumption that radiation-induced lesions were 'fixed' in the DNA prior to the first postirradiation mitosis. Lesion conversion was thought to occur during the initial round of DNA replication or as a consequence of error-prone enzymatic processing of lesions. The standard experimental protocols for the assessment of a variety of radiation-induced endpoints (cell death, specific locus mutations, neoplastic transformation and chromosome aberrations) evaluate these various endpoints at a single snapshot in time. In contrast with the aforementioned approaches, some studies have specifically assessed radiation effects as a function of time following exposure. Evidence has accumulated in support of the hypothesis that radiation exposure induces a persistent destabilization of the genome. This instability has been observed as a delayed expression of lethal mutations, as an enhanced rate of accumulation of non-lethal heritable alterations, and as a progressive intraclonal chromosomal heterogeneity. The genetic controls and biochemical mechanisms underlying radiation-induced genomic instability have not yet been delineated. The aim is to integrate the accumulated evidence that suggests that radiation exposure has a persistent effect on the stability of the mammalian genome.

  20. Protection of Retina by ?B Crystallin in Sodium Iodate Induced Retinal Degeneration

    PubMed Central

    Zhou, Peng; Kannan, Ram; Spee, Christine; Sreekumar, Parameswaran G.; Dou, Guorui; Hinton, David R.

    2014-01-01

    Age-related macular degeneration (AMD) is a leading cause of blindness in the developed world. The retinal pigment epithelium (RPE) is a critical site of pathology in AMD and ?B crystallin expression is increased in RPE and associated drusen in AMD. The purpose of this study was to investigate the role of ?B crystallin in sodium iodate (NaIO3)-induced retinal degeneration, a model of AMD in which the primary site of pathology is the RPE. Dose dependent effects of intravenous NaIO3 (20-70 mg/kg) on development of retinal degeneration (fundus photography) and RPE and retinal neuronal loss (histology) were determined in wild type and ?B crystallin knockout mice. Absence of ?B crystallin augmented retinal degeneration in low dose (20 mg/kg) NaIO3-treated mice and increased retinal cell apoptosis which was mainly localized to the RPE layer. Generation of reactive oxygen species (ROS) was observed with NaIO3 in mouse and human RPE which increased further after ?B crystallin knockout or siRNA knockdown, respectively. NaIO3 upregulated AKT phosphorylation and peroxisome proliferator–activator receptor–? (PPAR?) which was suppressed after ?B crystallin siRNA knockdown. Further, PPAR? ligand inhibited NaIO3-induced ROS generation. Our data suggest that ?B crystallin plays a critical role in protection of NaIO3-induced oxidative stress and retinal degeneration in part through upregulation of AKT phosphorylation and PPAR? expression. PMID:24874187

  1. Radiation effects in crystalline ceramics for the immobilization of high-level nuclear waste and plutonium

    Microsoft Academic Search

    W. J. Weber; R. C. Ewing; C. R. A. Catlow; T. Diaz de La Rubia; L. W. Hobbs; C. Kinoshita; Hj. Matzke; A. T. Motta; M. Nastasi; E. H. K. Salje; E. R. Vance; S. J. Zinkle

    1998-01-01

    This review provides a comprehensive evaluation of the state-of-knowledge of radiation effects in crystalline ceramics that may be used for the immobilization of high-level nuclear waste and plutonium. The current understanding of radiation damage processes, defect generation, microstructure development, theoretical methods, and experimental methods are reviewed. Fundamental scientific and technological issues that offer opportunities for research are identified. The most

  2. Heat-induced structural transitions of alpha-crystallin studied by small-angle neutron scattering

    NASA Astrophysics Data System (ADS)

    Krivandin, A. V.; Kuklin, A. I.; Muranov, K. O.; Murugova, T. N.; Kozlov, S. S.; Genkina, N. K.

    2012-03-01

    Alpha-crystallin from the bovine eye lens was studied by small-angle neutron scattering (SANS) in 90% D2O buffer solution at 20, 50, 60, 65, 75, 85 and 95°C. The temperature points for this study were specified on the basis of differential scanning calorimetric analysis of alpha-crystallin solutions which has shown two endothermic transitions with midpoints at 64.5 and 86°C. The SANS study revealed no significant alpha-crystallin quaternary structure alterations at 50°C as compared with 20°C. At 60-65°C the SANS data confirmed substantial alpha-crystallin quaternary structure rearrangements which resulted in the formation of alpha-crystallin oligomers with a similar shape but approximately twofold increased molecular weight as compared to the native state at 20°C. At higher temperatures (75, 85 and 95°C) the SANS patterns were very similar and were consistent with the scattering by rod-like particles with a cross-section radius of gyration ~55 This transformation of alpha-crystallin to the rod-like particles was evidently irreversible as these particles remained in solution after cooling to 20°C. Ab initio shape models of the native and high-temperature alpha-crystallin were retrieved with DAMMIN and DAMAVER software. Schematic model of alpha-crystallin heat-induced quaternary structure transitions was considered.

  3. Salt-induced phase separation in the liquid crystalline phase of phosphatidylcholines

    Microsoft Academic Search

    Michael Rappolt; Georg Pabst; Heinz Amenitsch; Peter Laggner

    2001-01-01

    The effects of alkali chlorides on multilamellar vesicles of various phosphatidylcholines in the lamellar liquid crystalline L?-phase were investigated by using small-angle X-ray scattering. At alkali chloride concentrations above 70 mM (LiCl) a phase separation in the liquid crystalline phase of POPC is induced. The splitting of the first and second order diffraction peaks into two major discrete components indicates

  4. Disorder-induced localization in crystalline phase-change materials

    NASA Astrophysics Data System (ADS)

    Siegrist, T.; Jost, P.; Volker, H.; Woda, M.; Merkelbach, P.; Schlockermann, C.; Wuttig, M.

    2011-03-01

    Localization of charge carriers in crystalline solids has been the subject of numerous investigations over more than half a century. Materials that show a metal-insulator transition without a structural change are therefore of interest. Mechanisms leading to metal-insulator transition include electron correlation (Mott transition) or disorder (Anderson localization), but a clear distinction is difficult. Here we report on a metal-insulator transition on increasing annealing temperature for a group of crystalline phase-change materials, where the metal-insulator transition is due to strong disorder usually associated only with amorphous solids. With pronounced disorder but weak electron correlation, these phase-change materials form an unparalleled quantum state of matter. Their universal electronic behaviour seems to be at the origin of the remarkable reproducibility of the resistance switching that is crucial to their applications in non-volatile-memory devices. Controlling the degree of disorder in crystalline phase-change materials might enable multilevel resistance states in upcoming storage devices.

  5. Disorder-induced localization in crystalline phase-change materials.

    PubMed

    Siegrist, T; Jost, P; Volker, H; Woda, M; Merkelbach, P; Schlockermann, C; Wuttig, M

    2011-03-01

    Localization of charge carriers in crystalline solids has been the subject of numerous investigations over more than half a century. Materials that show a metal-insulator transition without a structural change are therefore of interest. Mechanisms leading to metal-insulator transition include electron correlation (Mott transition) or disorder (Anderson localization), but a clear distinction is difficult. Here we report on a metal-insulator transition on increasing annealing temperature for a group of crystalline phase-change materials, where the metal-insulator transition is due to strong disorder usually associated only with amorphous solids. With pronounced disorder but weak electron correlation, these phase-change materials form an unparalleled quantum state of matter. Their universal electronic behaviour seems to be at the origin of the remarkable reproducibility of the resistance switching that is crucial to their applications in non-volatile-memory devices. Controlling the degree of disorder in crystalline phase-change materials might enable multilevel resistance states in upcoming storage devices. PMID:21217692

  6. Radiation-induced thermoacoustic imaging

    SciTech Connect

    Bowen, T.

    1983-05-31

    The acoustic wave generated by sudden thermal stress is used to obtain information non-invasively on the composition and structure of the stressed body. One or more acoustic transducers are coupled with the surface of the body to intercept the acoustic wave and generate a corresponding electrical signal. The sudden thermal stress is induced by a pulse of radiation which deposits energy causing a rapid, but very small, rise of temperature. The radiation may be ionizing radiation, such as high energy electrons, photons (x-rays), neutrons, or other charged particles. The radiation may also be non-ionizing radiation, such as rf and microwave electromagnetic radiation and ultrasonic radiation. The electrical signal from the acoustic transducer is amplified and supplied to a digitizer, which provides a continuous stream of digital words corresponding to samples of the amplified signal. Because in most situations of practical interest the s/n ratio of a single pulse is much less than unity, it is necessary to signalaverage the signals from many successive pulses. This is accomplished with a minicomputer or data processor suitably interfaced with the digitizer. The resulting data can then be suitably displayed as an image on a crt display or plotted or numerically printed out.

  7. BROOKHAVEN SCIENCE ASSOCIATES Radiation Induced Demagnetization of

    E-print Network

    Ohta, Shigemi

    BROOKHAVEN SCIENCE ASSOCIATES Radiation Induced Demagnetization of Nd-Fe-B Permanent Magnets P.K. Job Radiation Physicist NSLS II #12;BROOKHAVEN SCIENCE ASSOCIATES Radiation Induced Demagnetization Irradiation of Sample Magnets MCNPX Calculations for Comparison #12;BROOKHAVEN SCIENCE ASSOCIATES Radiation

  8. Crystalline polymorphism induced by charge regulation in ionic membranes.

    PubMed

    Leung, Cheuk-Yui; Palmer, Liam C; Kewalramani, Sumit; Qiao, Baofu; Stupp, Samuel I; Olvera de la Cruz, Monica; Bedzyk, Michael J

    2013-10-01

    The crystallization of molecules with polar and hydrophobic groups, such as ionic amphiphiles and proteins, is of paramount importance in biology and biotechnology. By coassembling dilysine (+2) and carboxylate (-1) amphiphiles of various tail lengths into bilayer membranes at different pH values, we show that the 2D crystallization process in amphiphile membranes can be controlled by modifying the competition of long-range and short-range interactions among the polar and the hydrophobic groups. The pH and the hydrophobic tail length modify the intermolecular packing and the symmetry of their crystalline phase. For hydrophobic tail lengths of 14 carbons (C14), we observe the coassembly into crystalline bilayers with hexagonal molecular ordering via in situ small- and wide-angle X-ray scattering. As the tail length increases, the hexagonal lattice spacing decreases due to an increase in van der Waals interactions, as demonstrated by atomistic molecular dynamics simulations. For C16 and C18 we observe a reentrant crystalline phase transition sequence, hexagonal-rectangular-C-rectangular-P-rectangular-C-hexagonal, as the solution pH is increased from 3 to 10.5. The stability of the rectangular phases, which maximize tail packing, increases with increasing tail length. As a result, for very long tails (C22), the possibility of observing packing symmetries other than rectangular-C phases diminishes. Our work demonstrates that it is possible to systematically exchange chemical and mechanical energy by changing the solution pH value within a range of physiological conditions at room temperature in bilayers of molecules with ionizable groups. PMID:24065818

  9. Ripple structure of crystalline layers in ion-beam-induced Si wafers

    SciTech Connect

    Hazra, S.; Chini, T.K.; Sanyal, M.K.; Grenzer, J.; Pietsch, U. [Surface Physics Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700 064 (India); Institut fur Physik, Universitat Potsdam, 14415 Potsdam (Germany)

    2004-09-15

    Ion-beam-induced ripple formation in Si wafers was studied by two complementary surface sensitive techniques, namely atomic force microscopy (AFM) and depth-resolved x-ray grazing incidence diffraction (GID). The formation of ripple structure at high doses ({approx}7x10{sup 17} ions/cm{sup 2}), starting from initiation at low doses ({approx}1x10{sup 17} ions/cm{sup 2}) of ion beam, is evident from AFM, while that in the buried crystalline region below a partially crystalline top layer is evident from GID study. Such ripple structure of crystalline layers in a large area formed in the subsurface region of Si wafers is probed through a nondestructive technique. The GID technique reveals that these periodically modulated wavelike buried crystalline features become highly regular and strongly correlated as one increases the Ar ion-beam energy from 60 to 100 keV. The vertical density profile obtained from the analysis of a Vineyard profile shows that the density in the upper top part of ripples is decreased to about 15% of the crystalline density. The partially crystalline top layer at low dose transforms to a completely amorphous layer for high doses, and the top morphology was found to be conformal with the underlying crystalline ripple.

  10. ?B-Crystallin Protects Retinal Tissue during Staphylococcus aureus- Induced Endophthalmitis?

    PubMed Central

    Whiston, Emily A.; Sugi, Norito; Kamradt, Merideth C.; Sack, Coralynn; Heimer, Susan R.; Engelbert, Michael; Wawrousek, Eric F.; Gilmore, Michael S.; Ksander, Bruce R.; Gregory, Meredith S.

    2008-01-01

    Bacterial infections of the eye highlight a dilemma that is central to all immune-privileged sites. On the one hand, immune privilege limits inflammation to prevent bystander destruction of normal tissue and loss of vision. On the other hand, bacterial infections require a robust inflammatory response for rapid clearance of the pathogen. We demonstrate that the retina handles this dilemma, in part, by activation of a protective heat shock protein. During Staphylococcus aureus-induced endophthalmitis, the small heat shock protein ?B-crystallin is upregulated in the retina and prevents apoptosis during immune clearance of the bacteria. In the absence of ?B-crystallin, mice display increased retinal apoptosis and retinal damage. We found that S. aureus produces a protease capable of cleaving ?B-crystallin to a form that coincides with increased retinal apoptosis and tissue destruction. We conclude that ?B-crystallin is important in protecting sensitive retinal tissue during destructive inflammation that occurs during bacterial endophthalmitis. PMID:18227158

  11. Kinetics of laser-induced surface melting and oxide removal in single-crystalline Ge

    Microsoft Academic Search

    J. Solís; F. Vega; C. N. Afonso

    1996-01-01

    The process of oxide removal in crystalline Ge using a pulsed ultraviolet laser has been studied by means of real-time reflectivity measurements with nanosecond resolution. The interaction of laser radiation with a clean, oxide-free surface has been characterized and the inhomogeneous and homogeneous energy density melting thresholds of c-Ge for 193rnm radiation have been determined. The values are 180 and

  12. Analysis of rapidly synthesized guest-filled porous complexes with synchrotron radiation: practical guidelines for the crystalline sponge method.

    PubMed

    Ramadhar, Timothy R; Zheng, Shao Liang; Chen, Yu Sheng; Clardy, Jon

    2015-01-01

    A detailed set of synthetic and crystallographic guidelines for the crystalline sponge method based upon the analysis of expediently synthesized crystal sponges using third-generation synchrotron radiation are reported. The procedure for the synthesis of the zinc-based metal-organic framework used in initial crystal sponge reports has been modified to yield competent crystals in 3 days instead of 2 weeks. These crystal sponges were tested on some small molecules, with two being unexpectedly difficult cases for analysis with in-house diffractometers in regard to data quality and proper space-group determination. These issues were easily resolved by the use of synchrotron radiation using data-collection times of less than an hour. One of these guests induced a single-crystal-to-single-crystal transformation to create a larger unit cell with over 500 non-H atoms in the asymmetric unit. This led to a non-trivial refinement scenario that afforded the best Flack x absolute stereochemical determination parameter to date for these systems. The structures did not require the use of PLATON/SQUEEZE or other solvent-masking programs, and are the highest-quality crystalline sponge systems reported to date where the results are strongly supported by the data. A set of guidelines for the entire crystallographic process were developed through these studies. In particular, the refinement guidelines include strategies to refine the host framework, locate guests and determine occupancies, discussion of the proper use of geometric and anisotropic displacement parameter restraints and constraints, and whether to perform solvent squeezing/masking. The single-crystal-to-single-crystal transformation process for the crystal sponges is also discussed. The presented general guidelines will be invaluable for researchers interested in using the crystalline sponge method at in-house diffraction or synchrotron facilities, will facilitate the collection and analysis of reliable high-quality data, and will allow construction of chemically and physically sensible models for guest structural determination. PMID:25537388

  13. Radiation induced estane polymer crosslinking

    SciTech Connect

    Fletcher, M. [Los Alamos National Lab., NM (United States); Foster, P. [Masson Hanger Pantex Plant, Amarillo, TX (United States)

    1997-12-01

    The exposure of polymeric materials to radiation has been known to induce the effects of crosslinking and degradation. The crosslinking phenomena comes about when two long chain polymers become linked together by a primary bond that extends the chain and increases the viscosity, molecular weight and the elastic modules of the polymer. This process has been observed in relatively short periods of time with fairly high doses of radiation, on the order of several megarads/hour. This paper address low dose exposure over long periods of time to determine what the radiation effects are on the polymeric binder material in PBX 9501. An experimental sample of binder material without explosives will be placed into a thermal and radiation field produced from a W-48 put mod 0. Another sample will be placed in a thermal environment without the radiation. The following is the test plan that was submitted to the Pantex process. The data presented here will be from the first few weeks of exposure and this test will be continued over the next few years. Subsequent data will hopefully be presented in the next compatibility and aging conference.

  14. Analysis of rapidly synthesized guest-filled porous complexes with synchrotron radiation: practical guidelines for the crystalline sponge method

    SciTech Connect

    Ramadhar, Timothy R. [Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 240 Longwood Avenue, Boston, Massachusetts, 02115 (United States); Zheng, Shao-Liang [Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts, 02138 (United States); Chen, Yu-Sheng [ChemMatCARS, Center for Advanced Radiation Sources, The University of Chicago c/o Advanced Photon Source, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois, 60439 (United States); Clardy, Jon, E-mail: jon-clardy@hms.harvard.edu [Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 240 Longwood Avenue, Boston, Massachusetts, 02115 (United States)

    2015-01-01

    This report describes complete practical guidelines and insights for the crystalline sponge method, which have been derived through the first use of synchrotron radiation on these systems, and includes a procedure for faster synthesis of the sponges. These guidelines will be applicable to crystal sponge data collected at synchrotrons or in-house facilities, and will allow researchers to obtain reliable high-quality data and construct chemically and physically sensible models for guest structural determination. A detailed set of synthetic and crystallographic guidelines for the crystalline sponge method based upon the analysis of expediently synthesized crystal sponges using third-generation synchrotron radiation are reported. The procedure for the synthesis of the zinc-based metal–organic framework used in initial crystal sponge reports has been modified to yield competent crystals in 3 days instead of 2 weeks. These crystal sponges were tested on some small molecules, with two being unexpectedly difficult cases for analysis with in-house diffractometers in regard to data quality and proper space-group determination. These issues were easily resolved by the use of synchrotron radiation using data-collection times of less than an hour. One of these guests induced a single-crystal-to-single-crystal transformation to create a larger unit cell with over 500 non-H atoms in the asymmetric unit. This led to a non-trivial refinement scenario that afforded the best Flack x absolute stereochemical determination parameter to date for these systems. The structures did not require the use of PLATON/SQUEEZE or other solvent-masking programs, and are the highest-quality crystalline sponge systems reported to date where the results are strongly supported by the data. A set of guidelines for the entire crystallographic process were developed through these studies. In particular, the refinement guidelines include strategies to refine the host framework, locate guests and determine occupancies, discussion of the proper use of geometric and anisotropic displacement parameter restraints and constraints, and whether to perform solvent squeezing/masking. The single-crystal-to-single-crystal transformation process for the crystal sponges is also discussed. The presented general guidelines will be invaluable for researchers interested in using the crystalline sponge method at in-house diffraction or synchrotron facilities, will facilitate the collection and analysis of reliable high-quality data, and will allow construction of chemically and physically sensible models for guest structural determination.

  15. EFFECT OF LASER INDUCED CRYSTALLINITY MODIFICATION ON BIODEGRADATION PROFILE OF POLY(L-LACTIC ACID)

    E-print Network

    Yao, Y. Lawrence

    EFFECT OF LASER INDUCED CRYSTALLINITY MODIFICATION ON BIODEGRADATION PROFILE OF POLY(L-LACTIC ACID(L-lactic acid) (PLLA) is promising in drug delivery applications, while its induction period of biodegradation attention due to their biocompatibility and biodegradability. Being biodegradable, poly(L-lactic acid) (PLLA

  16. Cooperative molecular field effect and induced orientational ordering effect in polar liquid crystalline films on metals.

    PubMed

    Taguchi, Dai; Kajimoto, Norifumi; Manaka, Takaaki; Iwamoto, Mitsumasa

    2007-07-28

    Using the in situ measurements of the surface potential built across the evaporated liquid crystalline 4-n-pentyl-4'-cyanobiphenyl (5CB) films on metal electrodes with different work functions, we studied the cooperative molecular field effect (CMFE) that assists carrier injection from electrodes and the induced orientational reordering in evaporated liquid crystalline molecules on metals. The surface potential increased, and then became constant after the 5CB monomolecular layer was formed. It was shown that the CMFE accompanying orientational reordering accounts for the metal work function dependence of the surface potential. Finally, the orientational reordering is discussed in terms of the anchoring energy. PMID:17672713

  17. Proximity-induced superconductivity in crystalline Cu and Co nanowires and nanogranular Co structures

    NASA Astrophysics Data System (ADS)

    Kompaniiets, M.; Dobrovolskiy, O. V.; Neetzel, C.; Begun, E.; Porrati, F.; Ensinger, W.; Huth, M.

    2014-08-01

    We report an experimental study of proximity effect-induced superconductivity in crystalline Cu and Co nanowires and a nanogranular Co nanowire structure in contact with a superconducting W-based floating electrode (inducer). For electrical resistance measurements up to three pairs of Pt-based voltage leads were attached at different distances beside the inner inducer electrode, thus allowing us to probe the proximity effect over a length of 2-12 ?m. Up to 30% resistance drops with respect to the normal-state value have been observed for the crystalline Co and Cu nanowires when sweeping the temperature below Tc of the inducer (5.2 K). By contrast, relative R(T) drops were found to be an order of magnitude smaller for the nanogranular Co nanowire structure. Our analysis of the resistance data shows that the superconducting proximity length in crystalline Cu and Co is about 1 ?m at 2.4 K, attesting to a long-range proximity effect in the Co nanowire. Moreover, this long-range proximity effect is insusceptible to magnetic fields up to 11 T, which is indicative of spin-triplet pairing. At the same time, proximity-induced superconductivity in the nanogranular Co nanowire is strongly suppressed due to the dominating Cooper pair scattering caused by its intrinsic microstructure.

  18. The ability of lens alpha crystallin to protect against heat-induced aggregation is age-dependent

    NASA Technical Reports Server (NTRS)

    Horwitz, J.; Emmons, T.; Takemoto, L.; Spooner, B. S. (Principal Investigator)

    1992-01-01

    Alpha crystallin was prepared from newborn and aged bovine lenses. SDS-PAGE and tryptic peptide mapping demonstrated that both preparations contained only the alpha-A and alpha-B chains, with no significant contamination of other crystallins. Compared with alpha crystallin from the aged lens, alpha crystallin from the newborn lens was much more effective in the inhibition of beta L crystallin denaturation and precipitation induced in vitro by heat. Together, these results demonstrate that during the aging process, the alpha crystallins lose their ability to protect against protein denaturation, consistent with the hypothesis that the alpha crystallins play an important role in the maintenance of protein native structure in the intact lens.

  19. Endotoxin-Induced Structural Transformations in Liquid Crystalline Droplets

    PubMed Central

    Lin, I-Hsin; Miller, Daniel S.; Bertics, Paul J.; Murphy, Christopher J.; de Pablo, Juan J.; Abbott, Nicholas L.

    2012-01-01

    The ordering of liquid crystals (LCs) is known to be influenced by surfaces and contaminants. Here, we report that picogram per milliliter concentrations of endotoxin in water trigger ordering transitions in micrometer-size LC droplets. The ordering transitions, which occur at surface concentrations of endotoxin that are less than 10?5 Langmuir, are not due to adsorbate-induced changes in the interfacial energy of the LC. The sensitivity of the LC to endotoxin was measured to change by six orders of magnitude with the geometry of the LC (droplet versus slab), supporting the hypothesis that interactions of endotoxin with topological defects in the LC mediate the response of the droplets. The LC ordering transitions depend strongly on glycophospholipid structure and provide new designs for responsive soft matter. PMID:21596951

  20. Alpha-crystallin-mediated protection of lens cells against heat and oxidative stress-induced cell death

    PubMed Central

    Christopher, Karen L.; Pedler, Michelle G.; Shieh, Biehuoy; Ammar, David A.; Petrash, J. Mark; Mueller, Niklaus H.

    2014-01-01

    In addition to their key role as structural lens proteins, ?-crystallins also appear to confer protection against many eye diseases, including cataract, retinitis pigmentosa, and macular degeneration. Exogenous recombinant ?-crystallin proteins were examined for their ability to prevent cell death induced by heat or oxidative stress in a human lens epithelial cell line (HLE-B3). Wild type ?A- or ?B-crystallin (WT-?A and WT-?B) and ?A- or ?B-crystallins, modified by the addition of a cell penetration peptide (CPP) designed to enhance uptake of proteins into cells (gC-?B, TAT-?B, gC-?A), were produced by recombinant methods. In vitro chaperone-like assays were used to assay the ability of ?-crystallins to protect client proteins from chemical or heat induced aggregation. In vivo viability assays were performed in HLE-B3 to determine whether pre-treatment with ?-crystallins reduced death after exposure to oxidative or heat stress. Most of the five recombinant ?-crystallin proteins tested conferred some in vitro protection from protein aggregation, with the greatest effect seen with WT-?B and gC-?B. All ?-crystallins displayed significant protection to oxidative stress induced cell death, while only the ?B-crystallins reduced cell death induced by thermal stress. Our findings indicate that the addition of the gC tag enhanced the protective effect of ?B-crystallin against oxidative but not thermally-induced cell death. In conclusion, modifications that increases the uptake of ?-crystallin proteins into cells, without destroying their chaperone-like activity and anti-apoptotic functions, create the potential to use these proteins therapeutically. PMID:24275510

  1. Alpha-crystallin-mediated protection of lens cells against heat and oxidative stress-induced cell death.

    PubMed

    Christopher, Karen L; Pedler, Michelle G; Shieh, Biehuoy; Ammar, David A; Petrash, J Mark; Mueller, Niklaus H

    2014-02-01

    In addition to their key role as structural lens proteins, ?-crystallins also appear to confer protection against many eye diseases, including cataract, retinitis pigmentosa, and macular degeneration. Exogenous recombinant ?-crystallin proteins were examined for their ability to prevent cell death induced by heat or oxidative stress in a human lens epithelial cell line (HLE-B3). Wild type ?A- or ?B-crystallin (WT-?A and WT-?B) and ?A- or ?B-crystallins, modified by the addition of a cell penetration peptide (CPP) designed to enhance the uptake of proteins into cells (gC-?B, TAT-?B, gC-?A), were produced by recombinant methods. In vitro chaperone-like assays were used to assay the ability of ?-crystallins to protect client proteins from chemical or heat induced aggregation. In vivo viability assays were performed in HLE-B3 to determine whether pre-treatment with ?-crystallins reduced death after exposure to oxidative or heat stress. Most of the five recombinant ?-crystallin proteins tested conferred some in vitro protection from protein aggregation, with the greatest effect seen with WT-?B and gC-?B. All ?-crystallins displayed significant protection to oxidative stress induced cell death, while only the ?B-crystallins reduced cell death induced by thermal stress. Our findings indicate that the addition of the gC tag enhanced the protective effect of ?B-crystallin against oxidative but not thermally-induced cell death. In conclusion, modifications that increase the uptake of ?-crystallin proteins into cells, without destroying their chaperone-like activity and anti-apoptotic functions, create the potential to use these proteins therapeutically. PMID:24275510

  2. Radiation-induced parotid cancer

    SciTech Connect

    Walker, M.J.; Chaudhuri, P.K.; Wood, D.C.; Das Gupta, T.K.

    1981-03-01

    A retrospective analysis of 72 cases of primary malignant tumors of the parotid gland treated at the University of Illinois Hospital, Chicago, from 1950 through 1978 revealed that six of these had developed from two to 24 years after irradiation of the head or neck for various benign and malignant neoplastic conditions. At the time of irradiation, ages ranged from 7 to 73 years; the sex distribution was equal. From our findings and those in 26 cases reported by various other authors, the following criteria are proposed for the designation of a parotid tumor as being radiation induced: (1) well-documented radiation exposure; (2) part of irradiation must incorporate the gland in which the cancer subseqently arises; (3) exposure to a minimum of 300 rads; and (4) minimum latent period of two years. In view of the widespread use in the past of heat and neck irradiation of benign neoplastic disease, the surgeon should be aware of this possible link with parotid gland tumor.

  3. Modeling radiation-induced cell cycle delays

    Microsoft Academic Search

    Anna Ochab-Marcinek; Ewa Gudowska-Nowak; Elena Nasonova; Sylvia Ritter

    2009-01-01

    Ionizing radiation is known to delay the cell cycle progression. In particular after particle exposure significant delays\\u000a have been observed and it has been shown that the extent of delay affects the expression of damage, such as chromosome aberrations.\\u000a Thus, to predict how cells respond to ionizing radiation and to derive reliable estimates of radiation risks, information\\u000a about radiation-induced cell

  4. Radiation-induced gene responses

    SciTech Connect

    Woloschak, G.E.; Paunesku, T.; Shearin-Jones, P.; Oryhon, J.

    1996-12-31

    In the process of identifying genes that are differentially regulated in cells exposed to ultraviolet radiation (UV), we identified a transcript that was repressed following the exposure of cells to a combination of UV and salicylate, a known inhibitor of NF-kappaB. Sequencing this band determined that it has identify to lactate dehydrogenase, and Northern blots confirmed the initial expression pattern. Analysis of the sequence of the LDH 5` region established the presence of NF-kappaB, Sp1, and two Ap-2 elements; two partial AP- 1; one partial RE, and two halves of E-UV elements were also found. Electromobility shift assays were then performed for the AP-1, NF- kappaB, and E-UV elements. These experiments revealed that binding to NF-kappaB was induced by UV but repressed with salicylic acid; UV did not affect AP-1 binding, but salicylic acid inhibited it alone or following UV exposure; and E-UV binding was repressed by UV, and salicylic acid had little effect. Since the binding of no single element correlated with the expression pattern of LDH, it is likely that multiple elements govern UV/salicylate-mediated expression.

  5. Temperature dependence of the radiative recombination coefficient in crystalline silicon from spectral photoluminescence

    SciTech Connect

    Nguyen, Hieu T., E-mail: hieu.nguyen@anu.edu.au; Macdonald, Daniel [Research School of Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, ACT 0200 (Australia); Baker-Finch, Simeon C. [Research School of Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, ACT 0200 (Australia); PV Lighthouse, Coledale, NSW 2515 (Australia)

    2014-03-17

    The radiative recombination coefficient B(T) in crystalline silicon is determined for the temperature range 90–363?K, and in particular from 270 to 350?K with an interval of 10?K, where only sparse data are available at present. The band-band absorption coefficient established recently by Nguyen et al. [J. Appl. Phys. 115, 043710 (2014)] via photoluminescence spectrum measurements is employed to compute the values of B(T) at various temperatures. The results agree very well with literature data from Trupke et al. [J. Appl. Phys. 94, 4930 (2003).] We present a polynomial parameterization describing the temperature dependence of the product of B(T) and the square of the intrinsic carrier density. We also find that B(T) saturates at a near constant value at room temperature and above for silicon samples with relatively low free carrier densities.

  6. Induced amphotropic and thermotropic ionic liquid crystallinity in phosphonium halides: "lubrication" by hydroxyl groups.

    PubMed

    Ma, Kefeng; Somashekhar, B S; Gowda, G A Nagana; Khetrapal, C L; Weiss, Richard G

    2008-03-18

    The influence of covalently attaching hydroxymethylene to the methyl groups of methyl-tri-n-alkylphosphonium halides (where the alkyl chains are decyl, tetradecyl, or octadecyl and the halide is chloride or bromide) or adding methanol as a solute to the salts on their solid, liquid-crystalline (smectic A2), and isotropic phases has been investigated using a variety of experimental techniques. These structural and compositional changes are found to induce liquid crystallinity in some cases and to enhance the temperature range and lower the onset temperature of the liquid-crystalline phases in some others. The results are interpreted in terms of the lengths of the three n-alkyl chains attached to the phosphorus cation, the nature of the halide anion, the influence of H-bonding interactions at the head group regions of the layered phases, and other solvent-solute interactions. The fact that at least 1 molar equiv of methanol must be added to effect complete (isothermal) conversion of a solid methyl-tri-n-alkylphosphonium salt to a liquid crystal demonstrates a direct and strong association between individual methanol molecules and the phosphonium salts. Possible applications of such systems are suggested. PMID:18278957

  7. Radiation-induced thyroid disease

    SciTech Connect

    Maxon, H.R.

    1985-09-01

    Ionizing radiation has been demonstrated to result in a number of changes in the human thyroid gland. At lower radiation dose levels (between 10 and 1500 rads), benign and malignant neoplasms appear to be the dominant effect, whereas at higher dose levels functional changes and thyroiditis become more prevalent. In all instances, the likelihood of the effect is related to the amount and type of radiation exposure, time since exposure, and host factors such as age, sex, and heredity. The author's current approach to the evaluation of patients with past external radiation therapy to the thyroid is discussed. The use of prophylactic thyroxine (T4) therapy is controversial. While T4 therapy may not be useful in preventing carcinogenesis when instituted many years after radiation exposure, theoretically T4 may block TSH secretion and stimulation of damaged cells to undergo malignant transformation when instituted soon after radiation exposure.

  8. Evolution of shock-induced orientation-dependent metastable states in crystalline aluminum.

    PubMed

    Budzevich, Mikalai M; Zhakhovsky, Vasily V; White, Carter T; Oleynik, Ivan I

    2012-09-21

    The evolution of orientation-dependent metastable states during shock-induced solid-liquid phase transitions in crystalline Al is followed using moving window molecular dynamics simulations. The orientation-dependent transition pathways towards an orientation-independent final state Hugoniot include both "cold melting" followed by recrystallization in [110]- and [111]-oriented shock waves and crystal overheating followed by melting in [100] shock waves. The orientation-dependent dynamics take place within a zone that can extend up to hundreds of nanometers behind the shock front. PMID:23005960

  9. Degenerate crystalline silicon films by aluminum-induced crystallization of boron-doped amorphous silicon

    NASA Astrophysics Data System (ADS)

    Hwang, J. D.; Luo, L. C.; Hsueh, T. J.; Hwang, S. B.

    2012-10-01

    Degenerate p-type crystalline silicon film with a hole concentration of 4 × 1021 cm-3 was investigated using aluminum-induced crystallization (AIC) of boron-doped amorphous silicon (a-Si). The AIC mechanism is different from that in the undoped AIC-Si. Boron atoms accumulate at Al layer forming a boron bump and segregate the Al atoms into Si layer, resulting to the formation of AlSi alloy. The degeneracy is not attributed to boron doping but instead to the AlSi alloy. Observations show that Al and Si layer transfer occurs not at original interface of Al and Si, but at the boron bump.

  10. UV-A-induced structural and functional changes in human lens deamidated ?B-crystallin

    PubMed Central

    Mafia, Kerri; Gupta, Ratna; Kirk, Marion; Wilson, L.; Barnes, Stephen

    2008-01-01

    Purpose To determine comparative effects of ultraviolet (UV)-A irradiation on structural and functional properties of wild type (WT) ?B-crystallin and its three deamidated mutant proteins (?B-Asn78Asp, ?B-Asn146Asp, and ?B-Asn78/146Asp). Methods Three deamidated mutants previously generated from recombinant WT ?B-crystallin, using a site-specific mutagenesis procedure as previously described [32], were used. The WT ?B-crystallin and its three deamidated species were exposed to UV-A light (320–400 nm) at intensities of 20 or 50 J/cm2. The UV-A-unexposed and UV-A-exposed preparations were examined for their chaperone activity, and their activities were correlated with the UV-A-induced structural changes. The structural properties studied included dimerization and degradation, intrinsic tryptophan (Trp) fluorescence, ANS (8-anilino-1-naphthalenesulfate)-binding, far ultraviolet circular dichroism (UV-CD) spectral analysis, molecular sizes by dynamic light scattering, and oxidation of Trp and methionine (Met) residues. Results The WT ?B-crystallin and its three deamidated mutant proteins showed enhanced dimerization to 40 kDa species and partial degradation with increasing doses during UV-A-exposure. Compared to the deamidation of asparagines (Asn) 78 residue to aspartic acid (Asp) or both Asn78 and Asn146 residues to Asp, the deamidation of Asn146 residue to Asp resulted in a greater loss of chaperone activity. The UV-A-induced loss of chaperone activity due to structural changes was studied. The ANS-binding data suggested that the ?B-Asn146Asp mutant protein had a relatively compact structure and an increase in surface hydrophobic patches compared to WT and two other deamidated proteins. Similarly, UV-A-exposure altered the Trp microenvironment in the deamidated mutant proteins compared to the WT ?B-crystallin. Far-UV CD spectral analyses showed almost no changes among WT and deamidated species on UV-A-exposure except that the ?B-Asn146Asp mutant protein showed maximum changes in the random coil structure relative to WT ?B-crystallin and two other deamidated proteins. The UV-A-exposure also resulted in the aggregation of WT and the three deamidated mutant proteins with species of greater mass compared to the non-UV-A exposed species. Among the four spots recovered after two-dimensional (2D)-gel electrophoresis from WT and the three deamidated species, the Met and Trp residues of ?B-Asn146Asp mutant showed maximum oxidation after UV-A exposure, which might account for its greater loss in chaperone activity compared to WT ?B-crystallin and two other deamidated species. Conclusions After UV-A-exposure, the deamidated ?B-Asn146Asp mutant protein showed a complete loss of chaperone activity compared to WT ?B and ?B-Asn78Asp and ?B-Asn78/146Asp deamidated species. Apparently, this loss of chaperone activity was due to oxidative changes leading to its greater structural alteration compared to other ?B-species. PMID:18334940

  11. Eicosapentaenoic acid inhibits glucose-induced membrane cholesterol crystalline domain formation through a potent antioxidant mechanism.

    PubMed

    Mason, R Preston; Jacob, Robert F

    2015-02-01

    Lipid oxidation leads to endothelial dysfunction, inflammation, and foam cell formation during atherogenesis. Glucose also contributes to lipid oxidation and promotes pathologic changes in membrane structural organization, including the development of cholesterol crystalline domains. In this study, we tested the comparative effects of eicosapentaenoic acid (EPA), an omega-3 fatty acid indicated for the treatment of very high triglyceride (TG) levels, and other TG-lowering agents (fenofibrate, niacin, and gemfibrozil) on lipid oxidation in human low-density lipoprotein (LDL) as well as membrane lipid vesicles prepared in the presence of glucose (200mg/dL). We also examined the antioxidant effects of EPA in combination with atorvastatin o-hydroxy (active) metabolite (ATM). Glucose-induced changes in membrane structural organization were measured using small angle x-ray scattering approaches and correlated with changes in lipid hydroperoxide (LOOH) levels. EPA was found to inhibit LDL oxidation in a dose-dependent manner (1.0-10.0µM) and was distinguished from the other TG-lowering agents, which had no significant effect as compared to vehicle treatment alone. Similar effects were observed in membrane lipid vesicles exposed to hyperglycemic conditions. The antioxidant activity of EPA, as observed in glucose-treated vesicles, was significantly enhanced in combination with ATM. Glucose treatment produced highly-ordered, membrane-restricted, cholesterol crystalline domains, which correlated with increased LOOH levels. Of the agents tested in this study, only EPA inhibited glucose-induced cholesterol domain formation. These data demonstrate that EPA, at pharmacologic levels, inhibits hyperglycemia-induced changes in membrane lipid structural organization through a potent antioxidant mechanism associated with its distinct, physicochemical interactions with the membrane bilayer. PMID:25449996

  12. Radiation-induced squamous sialometaplasia

    SciTech Connect

    Leshin, B.; White, W.L.; Koufman, J.A. (Wake Forest Univ., Winston-Salem, NC (USA))

    1990-07-01

    We describe a patient with recurrent acantholytic squamous cell carcinoma following radiation therapy. Mohs micrographic sections revealed extensive squamous sialometaplasia showing striking histologic similarity to the patient's squamous cell carcinoma. Criteria necessary to differentiate squamous sialometaplasia from neoplasm are presented. This differentiation is important to ensure adequate tumor resection without unnecessary sacrifice of tumor-free tissue.

  13. Radiation-induced instability and its relation to radiation carcinogenesis

    NASA Technical Reports Server (NTRS)

    Ullrich, R. L.; Ponnaiya, B.

    1998-01-01

    PURPOSE: A model that identifies radiation-induced genetic instability as the earliest cellular event in the multi-step sequence leading to radiation-induced cancer was previously proposed. In this paper ongoing experiments are discussed which are designed to test this model and its predictions in mouse mammary epithelial cells. RESULTS: Several lines of evidence are presented that appear to support this model: first, the development of delayed mutations in p53 following irradiation in altered growth variants; secondly, the high frequencies for the induction of both instability and transformation following irradiation in mammary epithelial cells; and finally, the demonstration that susceptibility to the induction of cytogenetic instability is a heritable trait that correlates with susceptibility to transformation and radiation-induced mammary cancer. Mice resistant to transformation and mammary cancer development are also resistant to the development of instability after irradiation. In contrast, mice sensitive to transformation and cancer are also sensitive to the development of cytogenetic instability. CONCLUSIONS: Data from this laboratory and from the studies cited above suggest a specific, and perhaps unique, role for radiation-induced instability as a critical early event associated with initiation of the carcinogenic process.

  14. Radiation Induced Bystander Effect in vivo

    PubMed Central

    Chai, Yunfei; Hei, Tom K.

    2010-01-01

    Radiation-induced bystander effect is defined as the induction of biological effects in cells that are not directly traversed by radiation, but merely in the presence of cells that are. Although radiation induced bystander effects have been well defined in a variety of in vitro models using a range of endpoints including clonogenic survival, mutations, neoplastic transformation, apoptosis, micronucleus, chromosomal aberrations and DNA double strand beaks, the mechanism(s) as well as the presence of such an effect in vivo are not well described. In this review, we summarize the evidence of radiation induced bystander effect in various in vivo systems including rodents, fish and plants. Many biological endpoints such as epigenetic changes, DNA damage, miRNA, apoptosis, cell proliferation, gene expression and tumorgenesis have been demonstrated in the non-targeted regions in vivo. Although the bystander effect is evolutionarily conserved in rodent systems, the bystander response depends on gender, tissue and strain. However, the studies about mechanism of radiation induced bystander effect in vivo are still limited. PMID:20634916

  15. Radiation Induced Bystander Effect in vivo.

    PubMed

    Chai, Yunfei; Hei, Tom K

    2008-01-01

    Radiation-induced bystander effect is defined as the induction of biological effects in cells that are not directly traversed by radiation, but merely in the presence of cells that are. Although radiation induced bystander effects have been well defined in a variety of in vitro models using a range of endpoints including clonogenic survival, mutations, neoplastic transformation, apoptosis, micronucleus, chromosomal aberrations and DNA double strand beaks, the mechanism(s) as well as the presence of such an effect in vivo are not well described. In this review, we summarize the evidence of radiation induced bystander effect in various in vivo systems including rodents, fish and plants. Many biological endpoints such as epigenetic changes, DNA damage, miRNA, apoptosis, cell proliferation, gene expression and tumorgenesis have been demonstrated in the non-targeted regions in vivo. Although the bystander effect is evolutionarily conserved in rodent systems, the bystander response depends on gender, tissue and strain. However, the studies about mechanism of radiation induced bystander effect in vivo are still limited. PMID:20634916

  16. Depth-dependent crystallinity of nano-crystalline silicon induced by step-wise variation of hydrogen dilution during hot-wire CVD

    NASA Astrophysics Data System (ADS)

    Arendse, C. J.; van Heerden, B. A.; Muller, T. F. G.; Cummings, F. R.; Oliphant, C. J.; Malgas, G. F.; Motaung, D. E.

    2015-06-01

    To induce an amorphous surface in a nano-crystalline silicon (nc-Si:H) thin film, the hydrogen dilution was reduced step-wise at fixed time intervals from 90 – 50% during the hotwire chemical vapour deposition process. This contribution reports on the structural properties of the resultant nc-Si:H thin film as a function of the deposition time. Raman spectroscopy, confirmed by high resolution transmission spectroscopy, indicates crystalline uniformity in the growth direction, accompanied by the progression of an amorphous surface layer as the deposition time is increased. The silicon- and oxygen bonding configurations were probed using infrared spectroscopy and electron energy loss spectroscopy. The growth mechanism is ascribed to the improved etching rate by atomic hydrogen in nano-crystalline silicon towards the film/substrate interface region. The optical properties were calculated by applying the effective medium approximation theory, where the existence of bulk and interfacial layers, as inferred from cross-sectional microscopy, were taken into account.

  17. Optically-induced non-linear optical effects in indium-tin oxide crystalline films

    NASA Astrophysics Data System (ADS)

    Kityk, I. V.; Ebothé, J.; Miedzinski, R.; Addou, M.; Sieder, H.; Karafiat, A.

    2003-06-01

    We have studied thin nanolayers (with thicknesses of about 1-2 nm) between In2O3:Sn (indium-tin oxide (ITO)) crystalline films and glass substrates using the photo-induced optical second harmonic generation (PISHG) method. The maximal PISHG response observed for the pump-probe delay times was about 26 ps. The performed experimental measurements and quantum chemical theoretical simulations show that the observed effects are caused by two factors. The first is caused by the film-glass interface potential gradient and the second is a consequence of additional trapping levels appearing in the energy gap, particularly due to Sn doping. PISHG may be considered as a sensitive tool for such kinds of semiconductors.

  18. Magnetic-field induced semimetal in topological crystalline insulator thin films

    NASA Astrophysics Data System (ADS)

    Ezawa, Motohiko

    2015-06-01

    We investigate electromagnetic properties of a topological crystalline insulator (TCI) thin film under external electromagnetic fields. The TCI thin film is a topological insulator indexed by the mirror-Chern number. It is demonstrated that the gap closes together with the emergence of a pair of gapless cones carrying opposite chirarities by applying in-plane magnetic field. A pair of gapless points have opposite vortex numbers. This is a reminiscence of a pair of Weyl cones in 3D Weyl semimetal. We thus present an a magnetic-field induced semimetal-semiconductor transition in 2D material. This is a giant-magnetoresistance, where resistivity is controlled by magnetic field. Perpendicular electric field is found to shift the gapless points and also renormalize the Fermi velocity in the direction of the in-plane magnetic field.

  19. Radiation-induced intestinal pseudoobstruction

    SciTech Connect

    Perino, L.E.; Schuffler, M.D.; Mehta, S.J.; Everson, G.T.

    1986-10-01

    A case of intestinal pseudoobstruction occurring 30 yr after radiation therapy is described. Mechanical causes of obstruction were excluded by laparotomy. Histology of full-thickness sections of the small bowel revealed vascular ectasia and sclerosis, serosal fibrosis, neuronal proliferation within the submucosa, and degeneration of the muscle fibers of the circular layer of the muscularis propria. On the basis of the clinical and histologic findings we conclude that, in this patient, intestinal pseudoobstruction was due to muscular and neuronal injury from abdominal irradiation.

  20. Radiation-Induced Phase Transformations in Ilmenite-Group Minerals

    SciTech Connect

    Mitchell, J. N.

    1997-12-31

    Transmission electron microscopy (TEM) is a powerful tool for characterizing and understanding radiation-induced structural changes in materials. We have irradiated single crystals of ilmenite (FeTiO{sub 3}) and geikielite (MgTiO{sub 3}) using ions and electrons to better understand the response of complex oxides to radiation. Ion irradiation experiments of bulk single crystals at 100 K show that ilmenite amorphized at doses of less than 1x10(exp15) Ar(2+)/sq cm and at a damage level in the peak damage region of 1 displacement per atom (dpa). Transmission electron microscopy and electron diffraction of a cross-sectioned portion of this crystal confirmed the formation of a 150 am thick amorphous layer. Geikielite proved to be more radiation resistant, requiring a flux of 2x10(exp 15) Xe(2+)/sq cm to induce amorphization at 100 K. This material did not amorphize at 470 K, despite a dose of 2.5 x10(exp 16) Xe(2+)/sq cm and a damage level as high as 25 dpa. Low temperature irradiations of electron- transparent crystals with 1 MeV Kr(+) also show that ilmenite amorphized after a damage level of 2.25 dpa at 175 K.Similar experiments on geikielite show that the microstructure is partially amorphous and partially crystalline after 10 dpa at 150 K. Concurrent ion and electron irradiation of both materials with 1 MeV Kr(+) and 0.9 MeV electrons produced dislocation loops in both materials, but no amorphous regions were formed. Differences in the radiation response of these isostructural oxides suggests that in systems with Mg-Fe solid solution, the Mg-rich compositions may be more resistant to structural changes.

  1. On the Pressure-Induced Loss of Crystallinity in Zinc- and Calcium-Phosphates

    SciTech Connect

    Shakhvorostov, D.; Mosey, N; Munoz-Paniagua, D; Pereira, G; Song, Y; Kasrai, M; Norton, P; Müser, M

    2008-01-01

    A recently suggested mechanism for the stress memory of various metal phosphates is investigated experimentally. Based on first-principles simulations [N. J. Mosey et al., Science 307, 1612 (2005)], it had been argued that atoms with flexible coordination, such as zinc or heavy-metal cations, act as network-forming agents, undergoing irreversible pressure-induced changes in bonding that lead to increased connectivity between phosphate anions. In the present study, orthophosphates of zinc and calcium were exposed to high pressures on surfaces and in diamond anvil cells. An additional set of first-principles simulations was accomplished on ?-orthophosphate of zinc, which suggested that this material was already cross-linked before compression but that it nevertheless underwent a reversible coordination change under pressure in agreement with the experimental results presented here. Raman spectra indicate an irreversible, pressure-induced loss of long-range crystallinity. The pressures required to induce these changes are around 7 GPa for the zinc phosphates, while they are close to 21 GPa for the calcium phosphates. Hydrogenation of the metal phosphate lowers the threshold pressure by approximately 2-3 GPa in both cases. Moreover, ?-orthophosphate of zinc could be partially amorphisized under nonisotropic pressure on copper foils.

  2. Nuclear Radiation Induced Noise in Infrared Detectors

    Microsoft Academic Search

    J. C. Pickel; M. D. Petroff

    1975-01-01

    A model for calculating the rate and amplitude of gamma ionization events in infrared detectors is presented. Several simplifying approximations to the actual, complex physical situation are applied in the model, thereby allowing an exact analytical formulation of the problem. Experimental measurements of nuclear-radiation induced noise pulse-height distributions and event rates are compared to predictions made using the model. Comparisons

  3. Nuclear radiation induced noise in infrared detectors

    Microsoft Academic Search

    J. C. Pickel; M. D. Petroff

    1975-01-01

    A model for calculating the rate and amplitude of gamma ionization events in infrared detectors is presented. Several simplifying approximations to the actual, complex physical situation are applied in the model, thereby allowing an exact analytical formulation of the problem. Experimental measurements of nuclear-radiation induced noise pulse-height distributions and event rates are compared to predictions made using the model. Comparisons

  4. Radiation-induced meningiomas in pediatric patients

    SciTech Connect

    Moss, S.D.; Rockswold, G.L.; Chou, S.N.; Yock, D.; Berger, M.S.

    1988-04-01

    Radiation-induced meningiomas rarely have latency periods short enough from the time of irradiation to the clinical presentation of the tumor to present in the pediatric patient. Three cases of radiation-induced intracranial meningiomas in pediatric patients are presented. The first involved a meningioma of the right frontal region in a 10-year-old boy 6 years after the resection and irradiation of a 4th ventricular medulloblastoma. Review of our pediatric tumor cases produced a second case of a left temporal fossa meningioma presenting in a 15-year-old boy with a history of irradiation for retinoblastoma at age 3 years and a third case of a right frontoparietal meningioma in a 15-year-old girl after irradiation for acute lymphoblastic leukemia. Only three cases of meningiomas presenting in the pediatric age group after radiation therapy to the head were detected in our review of the literature.

  5. Lateral solidification of a liquid crystalline semiconductor film induced by temperature gradient

    NASA Astrophysics Data System (ADS)

    Hoshino, Tomoya; Ito, Hayato; Fujieda, Ichiro; Hanasaki, Tomonori

    2013-09-01

    Derivatives of [1]benzothieno[3,2-b]benzothiophene (BTBT) are attracting much attention as a highly soluble, highmobility semiconductor material for thin-film transistor applications. These small molecules are known to organize themselves into a single crystalline structure after spin coating or drop casting. Charge transport in a single crystal material is anisotropic in nature. Hence, it is desired to control its orientation during growth or recrystallization so that the source and drain electrodes of a transistor are to be placed along a faster transport direction. We propose to generate temperature gradient in a heated liquid crystalline thin film to induce lateral recrystallization. In experiment, we tried two methods. First, an aluminum plate with two narrow ridges was inserted between a temperature-controlled stage and a square silicon substrate with a 200nm-thick SiO2 and a spin-coated C8-BTBT film. We raised the temperature of the stage to 120oC and let it cool gradually. During cooling at around 105oC , the color of the sample started to change, indicating a phase change. This change proceeded from the corners of the film and in about 30 seconds, darker regions merged at the center of the substrate. Second, the sample was placed at the edge of the stage. In this case, the color change started from the protruding corner of the sample and proceeded toward the other end. Micrograph observation revealed that cracks were formed in these films and they were perpendicular to the direction of the phase change.

  6. Delayed Radiation-Induced Vasculitic Leukoencephalopathy

    SciTech Connect

    Rauch, Philipp J. [Departments of Pathology and Neurosurgery, Yale University School of Medicine, New Haven, Connecticut (United States); Faculty of Medicine, University of Heidelberg, Heidelberg (Germany); Park, Henry S. [Departments of Pathology and Neurosurgery, Yale University School of Medicine, New Haven, Connecticut (United States); Knisely, Jonathan P.S. [Department of Radiation Medicine, North Shore University Hospital, Manhasset, New York (United States); Chiang, Veronica L. [Departments of Pathology and Neurosurgery, Yale University School of Medicine, New Haven, Connecticut (United States); Vortmeyer, Alexander O., E-mail: alexander.vortmeyer@yale.edu [Departments of Pathology and Neurosurgery, Yale University School of Medicine, New Haven, Connecticut (United States)

    2012-05-01

    Purpose: Recently, single-fraction, high-dosed focused radiation therapy such as that administered by Gamma Knife radiosurgery has been used increasingly for the treatment of metastatic brain cancer. Radiation therapy to the brain can cause delayed leukoencephalopathy, which carries its own significant morbidity and mortality. While radiosurgery-induced leukoencephalopathy is known to be clinically different from that following fractionated radiation, pathological differences are not well characterized. In this study, we aimed to integrate novel radiographic and histopathologic observations to gain a conceptual understanding of radiosurgery-induced leukoencephalopathy. Methods and Materials: We examined resected tissues of 10 patients treated at Yale New Haven Hospital between January 1, 2009, and June 30, 2010, for brain metastases that had been previously treated with Gamma Knife radiosurgery, who subsequently required surgical management of a symptomatic regrowing lesion. None of the patients showed pathological evidence of tumor recurrence. Clinical and magnetic resonance imaging data for each of the 10 patients were then studied retrospectively. Results: We provide evidence to show that radiosurgery-induced leukoencephalopathy may present as an advancing process that extends beyond the original high-dose radiation field. Neuropathologic examination of the resected tissue revealed traditionally known leukoencephalopathic changes including demyelination, coagulation necrosis, and vascular sclerosis. Unexpectedly, small and medium-sized vessels revealed transmural T-cell infiltration indicative of active vasculitis. Conclusions: We propose that the presence of a vasculitic component in association with radiation-induced leukoencephalopathy may facilitate the progressive nature of the condition. It may also explain the resemblance of delayed leukoencephalopathy with recurring tumor on virtually all imaging modalities used for posttreatment follow-up.

  7. Interference Phenomena in Medium Induced Radiation

    E-print Network

    Jorge Casalderrey-Solana; Edmond Iancu

    2011-06-20

    We consider the interference pattern for the medium-induced gluon radiation produced by a color singlet quark-antiquark antenna embedded in a QCD medium with size $L$ and `jet quenching' parameter $\\hat q$. Within the BDMPS-Z regime, we demonstrate that, for a dipole opening angle $\\theta_{q\\bar q} \\gg\\theta_c\\equiv {2}/{\\sqrt{\\hat q L^3}}$, the interference between the medium--induced gluon emissions by the quark and the antiquark is suppressed with respect to the direct emissions. This is so since direct emissions are delocalized throughout the medium and thus yield contributions proportional to $L$ while interference occurs only between emissions at early times, when both sources remain coherent. Thus, for $\\tqq \\gg\\theta_c$, the medium-induced radiation is the sum of the two spectra individually produced by the quark and the antiquark, without coherence effects like angular ordering. For $\\tqq \\ll\\theta_c$, the medium--induced radiation vanishes.

  8. Optically binary liquid crystalline blue phases induced by one-armed cholesterol-linked azobenzene molecules.

    PubMed

    Yin, Leicheng; Wu, Yeping; Gao, Jiangang; Ma, Jiajun; Hu, Zhijia; Zou, Gang; Zhang, Qijin

    2015-08-14

    A series of one-armed cholesterol-linked azobenzene molecules named CholXAzo with different spacers were synthesized, in which Chol6Azo was found to have induced blue phases (BPs) with a concentration of 4.0 wt%. Under irradiation of 385 nm UV light with a density of 15.0 mW cm(-2), photo-responsive behaviour of the 4.0 wt% Chol6Azo doped sample named B3 shows a sensitive temperature dependence, which means that at 38.0 °C a phase transition from BPs to the isotropic phase is induced; however, at 33.0 °C, this phase transition does not take place. Results from the research show that the optically binary phase transition behaviour of B3 is sensitive to the isomerization degree of Chol6Azo, which is closely related to the stability of the BP structure and there is a critical isomerization degree of 13.7% for the phase transition of the B3 liquid crystals. Further POM observation shows that the liquid crystal samples doped with different concentrations of Chol6Azo have an increasing transition temperature for photo-induced phase transition from the BP to the isotropic phase along with the increasing concentration of Chol6Azo, which are found to have the same changing tendency with phase transition temperature from the isotropic phase to BPs and a phase diagram is made to map the optically binary behaviour of Chol6Azo doped blue phase liquid crystals. At last, a simple pattern with the BP and the isotropic phase arranged at an interval was made in this optically binary liquid crystalline blue phase under a suitable photomask. PMID:26144839

  9. Crystalline Membranes

    NASA Technical Reports Server (NTRS)

    Tsapatsis, Michael (Inventor); Lai, Zhiping (Inventor)

    2008-01-01

    In certain aspects, the invention features methods for forming crystalline membranes (e.g., a membrane of a framework material, such as a zeolite) by inducing secondary growth in a layer of oriented seed crystals. The rate of growth of the seed crystals in the plane of the substrate is controlled to be comparable to the rate of growth out of the plane. As a result, a crystalline membrane can form a substantially continuous layer including grains of uniform crystallographic orientation that extend through the depth of the layer.

  10. Radiation induced fracture of the scapula

    SciTech Connect

    Riggs, J.H. III; Schultz, G.D.; Hanes, S.A. (Los Angeles College of Chiropractic, Whittier, CA (USA))

    1990-10-01

    A case of radiation induced osteonecrosis resulting in a fracture of the scapula in a 76-yr-old female patient with a history of breast carcinoma is presented. Diagnostic imaging, laboratory recommendations and clinical findings are discussed along with an algorithm for the safe management of patients with a history of cancer and musculoskeletal complaints. This case demonstrates the necessity of a thorough investigation of musculoskeletal complaints in patients with previous bone-seeking carcinomas.

  11. Radiation-induced morphea - a literature review.

    PubMed

    Spalek, M; Jonska-Gmyrek, J; Ga?ecki, J

    2015-02-01

    Radiation-induced morphea (RIM) is a rare and under-recognized skin complication of radiotherapy. It is commonly wrongly diagnosed as other dermatological conditions or malignancy because of similar clinical characteristics. This literature review analyses 66 cases that have been reported in the literature since 1989. The clinical appearance often includes pain and disfiguration of affected area, which may influence the patient's quality of life. There is no clear connection between the radiotherapy dose, the fractionation scheme, the use of a boost, age, the presence of other dermatological conditions or other connective tissue diseases and the occurrence of RIM. Its pathogenesis is still unclear, but several theories are proposed to explain this phenomenon. The available data suggest that the abnormally high secretion of some cytokines (interleukin 4, interleukin 5, transforming growth factor) induced by radiation causes an extensive fibrosis after an activation of fibroblasts. Histological confirmation is crucial in distinguishing RIM from similar-looking diseases, such as chronic radiation dermatitis, cancer recurrence, radiation, recall dermatitis, new carcinoma or cellulitis. There is no clear treatment regimen for this condition. Clinical outcome after therapy is often unsatisfactory. The commonly used methods and agents include: topical and systemic steroids, calcineurin inhibitors, systemic immunosuppressants including methotrexate, tacrolimus, heparin, hyaluronidase, phototherapy (UVA, UVA1, UVB, PUVA), systemic antibiotics, imiquimod, mycophenolate mofetil, photophoresis. The differential diagnosis is challenging and requires a multidisciplinary approach to avoid misdiagnosis and to plan appropriate treatment. PMID:25174551

  12. ?B-crystallin reduces ristocetin?induced soluble CD40 ligand release in human platelets: suppression of thromboxane A2 generation.

    PubMed

    Tsujimoto, Masanori; Doi, Tomoaki; Kuroyanagi, Gen; Yamamoto, Naohiro; Matsushima-Nishiwaki, Rie; Iida, Yuko; Enomoto, Yukiko; Iida, Hiroki; Ogura, Shinji; Otsuka, Takanobu; Tokuda, Haruhiko; Kozawa, Osamu; Iwama, Toru

    2015-07-01

    Our group has previously shown that ?B-crystallin (HSPB5), a small heat shock protein, inhibits human platelet aggregation by ristocetin, an activator of glycoprotein Ib/IX/V. In addition, it was demonstrated that glycoprotein Ib/IX/V activation induces soluble CD40 (sCD40) ligand release via thromboxane (TX) A2. In the present study, the effect of ?B-crystallin on the ristocetin-induced sCD40 ligand release in human platelets was investigated. The ristocetin-induced release of sCD40 ligand was suppressed by ?B-crystallin. In addition, ?B-crystallin reduced the ristocetin-stimulated production of 11-dehydro-TX B2, a stable metabolite of TXA2. ?B-crystallin did not suppress the platelet aggregation induced by U46619, a TXA2 receptor agonist. ?B-crystallin had little effect on the U46619-induced phosphorylation of p38 mitogen-activated protein kinase or sCD40 ligand release. In addition, ?B-crystallin failed to reduce the binding of SZ2, a monoclonal antibody against the sulfated sequence in the ?-chain of glycoprotein Ib, to the ristocetin-stimulated platelets. These results strongly suggest that ?B-crystallin extracellularly suppresses ristocetin-stimulated release of sCD40 ligand by inhibiting the TXA2 production in human platelets. PMID:25760062

  13. Crystal field effect induced topological crystalline insulators in monolayer IV-VI semiconductors.

    PubMed

    Liu, Junwei; Qian, Xiaofeng; Fu, Liang

    2015-04-01

    Two-dimensional (2D) topological crystalline insulators (TCIs) were recently predicted in thin films of the SnTe class of IV-VI semiconductors, which can host metallic edge states protected by mirror symmetry. As thickness decreases, quantum confinement effect will increase and surpass the inverted gap below a critical thickness, turning TCIs into normal insulators. Surprisingly, based on first-principles calculations, here we demonstrate that (001) monolayers of rocksalt IV-VI semiconductors XY (X = Ge, Sn, Pb and Y = S, Se, Te) are 2D TCIs with the fundamental band gap as large as 260 meV in monolayer PbTe. This unexpected nontrivial topological phase stems from the strong crystal field effect in the monolayer, which lifts the degeneracy between p(x,y) and p(z) orbitals and leads to band inversion between cation pz and anion px,y orbitals. This crystal field effect induced topological phase offers a new strategy to find and design other atomically thin 2D topological materials. PMID:25741907

  14. Proximity effect-induced superconductivity in crystalline metallic and ferromagnetic nanowires

    NASA Astrophysics Data System (ADS)

    Wang, Jian

    2011-03-01

    In a single crystal gold nanowire of 1.2 microns contacted by superconducting contacts, the proximity effect induced superconductivity was found to appear in two distinct steps. The superconducting and normal regions are separated by a mini-gap state of low critical field. We suggest that a superposition of two distinct magnetic-flux states, which correspond to quantum flux 0 and 1 trapped in the nanowire, can explain the mini-gap state. Furthermore, we observed clear periodic differential magnetoresistance oscillations in the superconducting to normal transition region, which corresponds to the generation or annihilation of one vortex. In crystalline ferromagnetic Co and Ni nanowires, unexpected long-range proximity effect was observed. Josephson current associated with weakly damped singlet superconducting correlations or triplet correlations produced by the contact regions may lead to the observed long ranged proximity effect. In addition, a large and sharp resistance peak around the transition temperature was observed in the wires exhibiting incomplete superconductivity. Further theoretical model needs to be developed to reveal the physics behind the ``peak effect.'' This work was supported by the Penn State MRSEC under NSF grant DMR-0820404.

  15. Radiation induced genomic instability in bystander cells

    NASA Astrophysics Data System (ADS)

    Zhou, H.; Gu, S.; Randers-Pehrson, G.; Hei, T.

    There is considerable evidence that exposure to ionizing radiation may induce a heritable genomic instability that leads to a persisting increased frequency of genetic and functional changes in the non-irradiated progeny of a wide variety of irradiated cells Genomic instability is measured as delayed expressions in chromosomal alterations micronucleus formation gene mutations and decreased plating efficiency During the last decade numerous studies have shown that radiation could induce bystander effect in non-irradiated neighboring cells similar endpoints have also been used in genomic instability studies Both genomic instability and the bystander effect are phenomena that result in a paradigm shift in our understanding of radiation biology In the past it seemed reasonable to assume that the production of single- and double-strand DNA breaks are due to direct energy deposition of energy by a charged particle to the nucleus It turns out that biology is not quite that simple Using the Columbia University charged particle microbeam and the highly sensitive human hamster hybrid AL cell mutagenic assay we irradiated 10 of the cells with a lethal dose of 30 alpha particles through the nucleus After overnight incubation the remaining viable bystander cells were replated in dishes for colony formation Clonal isolates were expanded and cultured for 6 consecutive weeks to assess plating efficiency and mutation frequency Preliminary results indicated that there was no significant decrease in plating efficiency among the bystander colonies when compared with

  16. Cathodoluminescence of radiation-induced zircon

    NASA Astrophysics Data System (ADS)

    Tsuchiya, Y.; Nishido, H.; Kayama, M.; Noumi, Y.

    2013-12-01

    Zircon occurs as a common accessory mineral in igneous, metamorphic and sedimentary rocks, and maintains much information on thermal history, metamorphic process and natural radiation dose accumulated in the mineral. U-Pb zircon dating (e.g., SHRIMP) is an important tool to interpret a history of the minerals at a micrometer-scale, where cathodoluminescence (CL) image has been used for identification of internal zones and domains having different chemical compositions and/or structures with a high spatial resolution. The CL of zircon is derived from various types of emission centers, which are derived from impurities such as rare earth elements (REE) and structural defects. In fact, the CL features of zircon are closely related to metamorphic process and radiation from contained radionuclides as well as geochemical condition of its formation. Most zircon has yellow emission, which seems to be assigned to UO2 centers or radiation-induced defect during metamictization of the lattice by alpha particles from the decay of U and Th. In this study, the radiation effects on zircon CL have been studied for He+ ion-implanted samples annealed at various temperatures to clarify radiation-induced defect centers involved with the yellow CL emission in zircon. Single crystals of zircon from Malawi (MZ), Takidani granodiorite (TZ) and Kurobegawa granite (KZ) were selected for He+ ion implantation experiments. The polished plates of the samples were implanted by He+ ion 4.0 MeV corresponding to energy of alpha particle from 238 U and 232Th. CL spectra in the range from 300 to 800 nm with 1 nm step were measured by a scanning electron microscopy-cathodoluminescence (SEM-CL). CL spectra of untreated and annealed zircon show emission bands at ~370 nm assigned to intrinsic defect centers and at ~480, ~580 and ~760 nm to trivalent Dy impurity centers (Cesbron et al., 1995; Gaft et al, 2005). CL emissions in the yellow-region were observed in untreated zircon. The TZ and KZ indicate youngest formation ages of 1.93-1.20 Ma and 1.7-0.9 Ma, respectively (Harayama,1994; Harayama et al., 2010) in the world. In this case, it is hardly to detect yellow CL emissions derived from radiation-induced defect center, suggesting low radiation dose of alpha radiation from 238U and 232Th on them. CL spectra of MZ, TZ and KZ showed an increase in the intensities of yellow emissions with an increase in radiation dose of He+ ion implantation, though He+ ion implantation reduces the intensities of their impurity centers. CL intensity in the yellow region depends on radiation dose of He+ ion implantation. Therefore, if the component of yellow emission could be deconvoluted from the CL spectra in zircon, its intensity will be used for an indicator to evaluate total exposure doses on it during geological age.

  17. Radiation induced carcinoma of the larynx

    SciTech Connect

    Amendola, B.E.; Amendola, M.A.; McClatchey, K.D.

    1985-07-01

    A squamous cell carcinoma presented in a 20 year old female nonsmoker three years after receiving a high dosage of radiation therapy to the base of the skull, face and entire neuroaxis and intense combination chemotherapy for a parameningeal rhabdomyosarcoma of the paranasal sinuses is reported. The larynx received a dose of about 3,500 rads over an eight week period. This dosage in conjunction with the associated intense chemotherapy regimen given to the patient may explain the appearance of a radiation induced tumor in an unusually short latent period. This certainly represents a risk in young patients in whom an aggressive combined approach is taken and the physician should be aware of.

  18. Radiation-induced intracranial malignant fibrous histiocytoma.

    PubMed

    Gonzalez-Vitale, J C; Slavin, R E; McQueen, J D

    1976-06-01

    An autopsy case of radiation-induced intracranial malignant fibrous histiocytoma (fibroxanthosarcoma) is reported. The tumor developed in the region of the sella turcica 11 years after high dose radiotherapy of a chromophobe adenoma of the pituitary. The tumor had infiltrated the base of the brain as well as the base of the skull. Metastases were not found. The tumor was composed of an admixture of bizarre fibroblasts, histiocytes and giant cells, xanthoma cells and siderophages, with a storiform fibrous stroma. This appears to be the first documented instance of a malignant fibrous histiocytoma occurring intracranially after local x-irradiation. PMID:181126

  19. Ultrafast Laser Induced Thermo-Elasto-Visco-Plastodynamics in Single Crystalline Silicon

    E-print Network

    Qi, Xuele

    2011-02-22

    A comprehensive model for describing the fundamental mechanism dictating the interaction of ultrafast laser pulse with single crystalline silicon wafer is formulated. The need for establishing the feasibility of employing lasers of subpicosecond...

  20. Ultrafast Laser Induced Thermo-Elasto-Visco-Plastodynamics in Single Crystalline Silicon 

    E-print Network

    Qi, Xuele

    2011-02-22

    A comprehensive model for describing the fundamental mechanism dictating the interaction of ultrafast laser pulse with single crystalline silicon wafer is formulated. The need for establishing the feasibility of employing lasers of subpicosecond...

  1. Electron-irradiation-induced phase segregation in crystalline and amorphous apatite: A TEM study

    Microsoft Academic Search

    A. MELDRUM; L. M. WANG; R. C. EWING

    Single crystals of natural F-rich apatite and 800 keV Kr 21 ion-beam-amorphized apatite were irradiated by an electron beam in a transmission electron microscope over a range of beam energies and beam currents. Irradiation of crystalline apatite using a high current density (16 A\\/cm 2 ) caused the precipitation of cubic CaO from the crystalline apatite matrix. Using a lower

  2. Protection from radiation-induced pneumonitis using cerium oxide nanoparticles

    Microsoft Academic Search

    Jimmie Colon; Luis Herrera; Joshua Smith; Swanand Patil; Chris Komanski; Patrick Kupelian; Sudipta Seal; D. Wayne Jenkins; Cheryl H. Baker

    2009-01-01

    In an effort to combat the harmful effects of radiation exposure, we propose that rare-earth cerium oxide (CeO2) nanoparticles (free-radical scavengers) protect normal tissue from radiation-induced damage. Preliminary studies suggest that these nanoparticles may be a therapeutic regenerative nanomedicine that will scavenge reactive oxygen species, which are responsible for radiation-induced cell damage. The effectiveness of CeO2 nanoparticles in radiation protection

  3. Surface-induced morphology and free-energy pathways in breakup of a nematic liquid crystalline cylinder

    NASA Astrophysics Data System (ADS)

    Goyal, Rajesh K.; Denn, Morton M.

    2008-08-01

    We compute the surface-induced morphology and the free-energy pathways as a cylindrical liquid crystalline filament with preferred homeotropic (orthogonal) interface orientation passes through a sequence of growing sinusoidal perturbations and breaks up into droplets. Liquid crystalline morphology is determined using a simulated annealing algorithm [R. K. Goyal and M. M. Denn, Phys. Rev. E, 75, 021704 (2007)] to minimize the Oseen-Frank free energy. A first-order morphological transition with a finite energy barrier is required when the perturbation amplitude exceeds a critical value, and it is possible that progress towards breakup will be kinetically trapped in a varicose cylindrical shape. This result may be related to the apparent kinetic trapping of dispersed nematic 4' -octyl-4-biphenylcarbonitrile in a gel state reported by Inn and Denn [J. Rheol., 49, 887 (2005)].

  4. Ion beam induced luminescence: Relevance to radiation induced bystander effects

    NASA Astrophysics Data System (ADS)

    Ahmad, S. B.; McNeill, F. E.; Byun, S. H.; Prestwich, W. V.; Seymour, C.; Mothersill, C. E.

    2012-10-01

    The aim of this work is quantify the light emitted as a result of charged particle interaction in materials which may be of relevance to radiation induced "bystander effects" studies. We have developed a system which employs single photon counting to measure the light emitted from samples irradiated under vacuum by a charged particle beam. The system uses a fast photomultiplier tube with a peak cathode response at 420 nm. It has been tested in a proof-of-principle experiment using polystyrene targets. Light output, as a result of irradiation, was measured. The luminescence yield appears to have a non-linear behavior with the incident ion fluence: it rises exponentially to an asymptotic value. The target was irradiated with beam energies varying from 1 to 2 MeV and showed saturation at or before an incident fluence rate of 3 × 1013 H+/cm2 s. The average saturation value for the photon output was found to be 40 × 106 cps. Some measurements were performed using filters to study the emission at specific wavelengths. In the case of filtered light measurements, the photon output was found to saturate at 28 × 103, 10 × 106, and 35 × 106 cps for wavelengths of 280 ± 5 nm, 320 ± 5 nm and 340 ± 5 nm respectively. The light output reaches a maximum value because of damage induced in the polymer. Our measurements indicate a "damage cross section" of the order of 10-14 cm2. The average radiant intensity was found to increase at wavelengths of 280 and 320 nm when the proton energy was increased. This was not found to occur at 340 nm. In conclusion, the light emission at specific wavelengths was found to depend upon the incident proton fluence and the proton energy. The wavelengths of the emitted light measured in this study have significance for the understanding of radiation induced bystander effects.

  5. Geometric pumping induced by shear flow in dilute liquid crystalline polymer solutions

    NASA Astrophysics Data System (ADS)

    Yabunaka, Shunsuke; Hayakawa, Hisao

    2015-02-01

    We investigate nonlinear rheology of dilute liquid crystalline polymer solutions under time dependent two-directional shear flow. We analyze the Smoluchowski equation, which describes the dynamics of the orientation of a liquid crystalline polymer, by employing technique of the full counting statistics. In the adiabatic limit, we derive the expression for time integrated currents generated by a Berry-like curvature. Using this expression, it is shown that the expectation values of the time-integrated angular velocity of a liquid crystalline polymer and the time-integrated stress tensor are generally not zero even if the time average of the shear rate is zero. The validity of the theoretical calculations is confirmed by direct numerical simulations of the Smoluchowski equation. Nonadiabatic effects are also investigated by means of simulations and it is found that the time-integrated stress tensor depends on the speed of the modulation of the shear rate if we adopt the isotropic distribution as an initial state.

  6. Guanidine hydrochloride induced reversible dissociation and denaturation of duck delta2-crystallin.

    PubMed

    Lee, H J; Chang, G G

    2000-07-01

    The tetrameric delta2-crystallin from duck lens exhibits a reversible dissociation-denaturation process in solutions containing guanidine hydrochloride (GdnHCl). Sigmoidal or biphasic curves for the dissociation/denaturation processes, obtained using different methods of structural analysis, as a function of GdnHCl concentration were not coincidental with each other. delta2-crystallin in 0.91 M GdnHCl existed primarily as a monomer, which had no endogenous argininosuccinate lyase activity. After dilution of the GdnHCl-treated protein, the monomers reassociated into tetramers with concomitant recovery of enzyme activity. The sigmoidal recovery of enzyme activity demonstrates a cooperative hysteretic reactivation process. When the concentration of GdnHCl was higher than 1.2 M, various partially unfolded soluble forms of delta2-crystallin were produced from the dissociated monomers as shown by size-exclusion chromatography. The formation of a partially unfolded intermediate during the dissociation-denaturation process is proposed. PMID:10866796

  7. The Formation of Crystalline Dust in AGB Winds from Binary Induced Spiral Shocks

    E-print Network

    R. G. Edgar; J. Nordhaus; E. Blackman; A. Frank

    2007-09-14

    As stars evolve along the Asymptotic Giant Branch, strong winds are driven from the outer envelope. These winds form a shell, which may ultimately become a planetary nebula. Many planetary nebulae are highly asymmetric, hinting at the presence of a binary companion. Some post-Asymptotic Giant Branch objects are surrounded by torii of crystalline dust, but there is no generally accepted mechanism for annealing the amorphous grains in the wind to crystals. In this Letter, we show that the shaping of the wind by a binary companion is likely to lead to the formation of crystalline dust in the orbital plane of the binary.

  8. Analysis of radiation pressure induced nonlinear optofluidics.

    PubMed

    Xu, Yong; Zhang, Peng; Jung, Sunghwan; Lee, Aram

    2014-11-17

    We analyze two nonlinear optofluidic processes where nonlinearity is induced by the interplay between optical field and liquid interface. Specifically, guided optical waves generate radiation pressure on the liquid interface, which can in turn distort the liquid interface and modify the properties of the optical field. In the first example, we discuss the feasibility of nonlinear optofluidic solitons, where optical field is governed by the nonlinear Schrödinger equation and nonlinearity is effectively determined by liquid properties. Then, we analyze a nonlinear optofluidic process associated with a high quality (Q) factor whispering gallery mode (WGM) in a liquid droplet. Similar to Kerr effects, the WGM can produce a frequency shift proportional to the WGM power. Using liquid properties that are experimentally attainable, we find that it may only take a few photons to generate measurable WGM resonance shift. Such a possibility may eventually lead to nonlinear optics at single photon energy level. PMID:25402127

  9. Scientific foundations of development of new chemically and radiation-resistant cd-containing crystalline materials

    Microsoft Academic Search

    A. A. Lukuttsov; M. L. Spiridonova; N. A. Kulagina; A. I. Orlova; V. I. Pet’kov; I. A. Kulikov

    2004-01-01

    Cadmium phosphate Cd0.5Zr2(PO4)3 was obtained by precipitation from aqueous solutions and studied by means of X-ray phase analysis and IR spectroscopy. The behavior of powdered and ceramic samples in water, aqueous ammonia solutions, nitric acid, EDTA, and also in gamma-radiation fields (60Co source), was examined. Experimental characteristics of the chemical and radiation stability are presented.

  10. Effect of Laser Induced Crystallinity Modification on Biodegradation Profile of Poly(L-Lactic Acid)

    E-print Network

    Yao, Y. Lawrence

    (L-Lactic Acid) Shan-Ting Hsu, Huade Tan, Y. Lawrence Yao Department of Mechanical Engineering, Columbia University, New York, NY 10027 Abstract Poly(L-lactic acid) (PLLA) is of interest in drug delivery: poly(L-lactic acid); laser treatment; biodegradation; crystallinity; drug delivery #12;2 1

  11. Radiation-induced soft errors in advanced semiconductor technologies

    Microsoft Academic Search

    Robert C. Baumann

    2005-01-01

    The once-ephemeral radiation-induced soft error has become a key threat to advanced commercial electronic components and systems. Left unchallenged, soft errors have the potential for inducing the highest failure rate of all other reliability mechanisms combined. This article briefly reviews the types of failure modes for soft errors, the three dominant radiation mechanisms responsible for creating soft errors in terrestrial

  12. Supersymmetry breaking induced by radiative corrections

    NASA Astrophysics Data System (ADS)

    Bajc, Borut; Lavignac, Stéphane; Mede, Timon

    2012-07-01

    We show that simultaneous gauge and supersymmetry breaking can be induced by radiative corrections, à la Coleman-Weinberg. When a certain correlation among the superpotential parameters is present, a local supersymmetry-breaking minimum is induced in the effective potential of a gauge non-singlet field, in a region where the tree-level potential is almost flat. Supersymmetry breaking is then transmitted to the MSSM through gauge and chiral messenger loops, thus avoiding the suppression of gaugino masses characteristic of direct gauge mediation models. The use of a single field ensures that no dangerous tachyonic scalar masses are generated at the one-loop level. We illustrate this mechanism with an explicit example based on an SU(5) model with a single adjoint. An interesting feature of the scenario is that the GUT scale is increased with respect to standard unification, thus allowing for a larger colour Higgs triplet mass, as preferred by the experimental lower bound on the proton lifetime.

  13. [gamma]-radiation-induced changes in the chemical and physical structure of poly(ethylene terephthalate)

    SciTech Connect

    Jin, Ho-Seon.

    1992-01-01

    Poly(ethylene terephthalate) (PET) film was irradiated with [gamma]-rays in air at doses from 0 to 620 Mrad, and at the rate of 0l8 to 1.0 Mrad/hr. Radiation-induced physical structure changes were studied by DMA and DSC measurements. Tensile properties were measured to find interrelationships with chemical and physical structure changes. Below 100 Mrad, PET shows little change in NMR and IR spectra. Fluorescence emission spectra, however, show the presence and increase of monohydroxy-substituted phenylene groups. This hydroxylation appears to stabilize the polymer. The phenylene group in PET also contributes to radiation-resistance. The amorphous-crystalline interfaces impede the penetration of oxygen and slow the oxidative chain scission. Between 100 and 215 Mrad, UV studies reveal that the rates of reaction begin to change rapidly. Chain scission appears to take place first in the interspherulitic amorphous regions and then in the intraspherulitic (interlamella) regions. [gamma]-Radiation-induced oxidative degradation shows aspects of both photolysis and of thermooxidative degradation (proton and carbon-13 NMR, and IR studies). It was concluded that the crystalline phase breaks down in to smaller crystallites, and these smaller crystallites grow in size by acting as nucleating sites. Tensile measurements show that throughout the range of irradiation studied the tensile strength at break and the percent elongation decrease. The tensile strength decreases uniformly and the percent elongation exhibits a more rapid decrease above 100 Mrad. The results of this study lead to the conclusion that [gamma]-radiation-induced oxidative degradation of PET involves products that are seen in both photolysis and thermooxidation.

  14. Obstructive jaundice due to radiation-induced hepatic duct stricture

    SciTech Connect

    Chandrasekhara, K.L.; Iyer, S.K.

    1984-10-01

    A case of obstructive jaundice due to radiation-induced hepatic duct stricture is reported. The patient received postoperative radiation for left adrenal carcinoma, seven years prior to this admission. The sequelae of hepatobiliary radiation and their management are discussed briefly.

  15. [Radiation-induced cavernoma of the central nervous system].

    PubMed

    Melot, A; Laquerrière, A; Hanzen, S; Fréger, P; Proust, F

    2007-12-01

    Central nervous system radiation-induced cavernoma (RIC) is a rare entity. We report one case with a review of the literature. This case illustrates the following features: mean age of 11.7 years at time of radiation and mean latency period of nine years for these RIC, which are often numerous (38%), and located in the field of the craniospinal radiation therapy. This nosological entity belongs to the spectrum of radiation-induced lesions, and requires a long-term MRI follow up in patients who underwent cranial radiation therapy. PMID:18061632

  16. Radiation induced segregation in candidate fusion reactor alloys

    NASA Astrophysics Data System (ADS)

    Brimhall, J. L.; Baer, D. R.; Jones, R. H.

    The effect of radiation on surface segregation of minor and impurity elements has been studied in four candidate fusion reactor alloys. Radiation induced surface segregation of phosphorus was found in both 316 type stainless steel and in Nimonic PE-16. Segregation and depletion of the other alloying elements in 316 stainless steel agreed with that reported by other investigators. Segregation of nitrogen in ferritic HT-9 was enhanced by radiation but no phosphorus segregation was detected. No significant radiation enhanced or induced segregation was observed in a Ti-6Al-4V alloy. The results indicate that radiation enhanced grain boundary segregation could contribute to the embrittlement of 316 SS and PE-16.

  17. Treatment of radiation-induced cystitis with hyperbaric oxygen

    SciTech Connect

    Weiss, J.P.; Boland, F.P.; Mori, H.; Gallagher, M.; Brereton, H.; Preate, D.L.; Neville, E.C.

    1985-08-01

    The effects of hyperbaric oxygen on radiation cystitis have been documented in 3 patients with radiation-induced hemorrhagic cystitis refractory to conventional therapy. Cessation of gross hematuria and reversal of cystoscopic bladder changes were seen in response to a series of hyperbaric oxygen treatments of 2 atmosphere absolute pressure for 2 hours. To our knowledge this is the first report of cystoscopically documented healing of radiation-induced bladder injury.

  18. Alpha-decay-induced fracturing in zircon - The transition from the crystalline to the metamict state

    NASA Technical Reports Server (NTRS)

    Chakoumakos, Bryan C.; Murakami, Takashi; Lumpkin, Gregory R.; Ewing, Rodney C.

    1987-01-01

    Zonation due to alpha-decay damage in a natural single crystal of zircon from Sri Lanka is discussed. The zones vary in thickness on a scale from one to hundreds of microns. The uranium and thorium concentrations vary from zone to zone such that the alpha decay dose is between 0.2 x 10 to the 16th and 0.8 x 10 to the 16th alpha-events per milligram. The transition from the crystalline to the aperiodic metamict state occurs over this dose range. At doses greater than 0.8 x 10 to the 16th alpha events/mg there is no evidence for long-range order. This type of damage will accumulate in actinide-bearing, ceramic nuclear waste forms. The systematic pattern of fractures would occur in crystalline phases that are zoned with respect to actinide radionuclides.

  19. Excitation Spectrum of Crystalline Tetracene Fluorescence: A Probe for Optically-Induced Singlet-Exciton Fission

    Microsoft Academic Search

    G. Vaubel; H. Baessler

    1971-01-01

    The intrinsic fluorescence efficiency of crystalline tetracene depends on the energy of the exiciting light. It decreases for Eexc > 2.48 eV displaying a minimum at Eexc = 2.51 eV which is identical with the energy of the triplet pair state. It is suggested that an optically populated, vibronically excited S 1-state. which is iso-energetic with the triplet pair state

  20. Radiation-induced cataract in astronauts and cosmonauts

    Microsoft Academic Search

    Zahra Noushin Rastegar; Peter Eckart; Manfred Mertz

    2002-01-01

    Background. Opacification of the ocular lens is an important effect of exposure to ionizing radiation. Astronauts and cosmonauts are exposed to relatively high doses of all types of radiation in space, including high-energy particle radiation. A study was initiated to examine the lenses of the eyes of astronauts\\/cosmonauts to detect signs of radiation-induced cataracts. The aim of this study was

  1. Radiation induced damage and recovery in poly(3-hexyl thiophene) based polymer solar cells.

    PubMed

    Li, Gang; Yang, Yang; Devine, R A B; Mayberry, Clay

    2008-10-22

    Polymer solar cells have been characterized during and after x-ray irradiation. The open circuit voltage, dark current and power conversion efficiency show degradation consistent with the generation of defect states in the polymer semiconductor. The polymer solar cell device remained functional with exposure to a considerable dose (500 krad (SiO(2))) and showed clear signs of recovery upon removal of the irradiation source (degraded from 4.1% to 2.2% and recovered to 2.9%). Mobility-relaxation time variation, derived from J-V measurement, clearly demonstrates that radiation induced defect generation mechanisms in the organic semiconductor are active and need to be further studied. Optical transmission results ruled out the possibility of reduced light absorption and/or polymer crystallinity. The results suggest that organic solar cells are sufficiently radiation tolerant to be useful for space applications. PMID:21832674

  2. Radiation induces senescence and a bystander effect through metabolic alterations

    PubMed Central

    Liao, E-C; Hsu, Y-T; Chuah, Q-Y; Lee, Y-J; Hu, J-Y; Huang, T-C; Yang, P-M; Chiu, S-J

    2014-01-01

    Cellular senescence is a state of irreversible growth arrest; however, the metabolic processes of senescent cells remain active. Our previous studies have shown that radiation induces senescence of human breast cancer cells that display low expression of securin, a protein involved in control of the metaphase–anaphase transition and anaphase onset. In this study, the protein expression profile of senescent cells was resolved by two-dimensional gel electrophoresis to investigate associated metabolic alterations. We found that radiation induced the expression and activation of glyceraldehyde-3-phosphate dehydrogenase that has an important role in glycolysis. The activity of lactate dehydrogenase A, which is involved in the conversion of pyruvate to lactate, the release of lactate and the acidification of the extracellular environment, was also induced. Inhibition of glycolysis by dichloroacetate attenuated radiation-induced senescence. In addition, radiation also induced activation of the 5?-adenosine monophosphate-activated protein kinase (AMPK) and nuclear factor kappa B (NF-?B) pathways to promote senescence. We also found that radiation increased the expression of monocarboxylate transporter 1 (MCT1) that facilitates the export of lactate into the extracellular environment. Inhibition of glycolysis or the AMPK/NF-?B signalling pathways reduced MCT1 expression and rescued the acidification of the extracellular environment. Interestingly, these metabolic-altering signalling pathways were also involved in radiation-induced invasion of the surrounding, non-irradiated breast cancer and normal endothelial cells. Taken together, radiation can induce the senescence of human breast cancer cells through metabolic alterations. PMID:24853433

  3. Radiation induces senescence and a bystander effect through metabolic alterations.

    PubMed

    Liao, E-C; Hsu, Y-T; Chuah, Q-Y; Lee, Y-J; Hu, J-Y; Huang, T-C; Yang, P-M; Chiu, S-J

    2014-01-01

    Cellular senescence is a state of irreversible growth arrest; however, the metabolic processes of senescent cells remain active. Our previous studies have shown that radiation induces senescence of human breast cancer cells that display low expression of securin, a protein involved in control of the metaphase-anaphase transition and anaphase onset. In this study, the protein expression profile of senescent cells was resolved by two-dimensional gel electrophoresis to investigate associated metabolic alterations. We found that radiation induced the expression and activation of glyceraldehyde-3-phosphate dehydrogenase that has an important role in glycolysis. The activity of lactate dehydrogenase A, which is involved in the conversion of pyruvate to lactate, the release of lactate and the acidification of the extracellular environment, was also induced. Inhibition of glycolysis by dichloroacetate attenuated radiation-induced senescence. In addition, radiation also induced activation of the 5'-adenosine monophosphate-activated protein kinase (AMPK) and nuclear factor kappa B (NF-?B) pathways to promote senescence. We also found that radiation increased the expression of monocarboxylate transporter 1 (MCT1) that facilitates the export of lactate into the extracellular environment. Inhibition of glycolysis or the AMPK/NF-?B signalling pathways reduced MCT1 expression and rescued the acidification of the extracellular environment. Interestingly, these metabolic-altering signalling pathways were also involved in radiation-induced invasion of the surrounding, non-irradiated breast cancer and normal endothelial cells. Taken together, radiation can induce the senescence of human breast cancer cells through metabolic alterations. PMID:24853433

  4. Radiation-induced segregation in candidate fusion-reactor alloys

    SciTech Connect

    Brimhall, J.L.; Baer, D.R.; Jones, R.H.

    1981-07-01

    The effect of radiation on surface segregation of minor and impurity elements has been studied in four candidate fusion reactor alloys. Radiation induced surface segregation of phosphorus was found in both 316 type stainless steel and in Nimonic PE-16. Segregation and depletion of the other alloying elements in 316 stainless steel agreed with that reported by other investigators. Segregation of nitrogen in ferritic HT-9 was enhanced by radiation but no phosphorus segregation was detected. No significant radiation enhanced or induced segregation was observed in a Ti-6Al-4V alloy. The results indicate that radiaton enhanced grain boundary segregation could contribute to the embrittlement of 316 SS and PE-16.

  5. Effect of radiation induced crosslinking and degradation of ETFE films

    NASA Astrophysics Data System (ADS)

    Zen, H. A.; Ribeiro, G.; Geraldes, A. N.; Souza, C. P.; Parra, D. F.; Lugão, A. B.

    2013-03-01

    In this study the ETFE film with 125 ?m of thickness was placed inside a nylon bag and filled with either acetylene, nitrogen or oxygen. Following the procedure, the samples were irradiated at 5, 10 and 20 kGy. The physical and chemical properties of the modified and pristine films were evaluated by rheological and thermal analyses (TG and DSC), X-ray diffraction (XRD) and infrared spectroscopy (IR-ATR). In rheological analysis the storage modulus (G') indicates opposite profiles when the atmospheres (acetylene and oxygen) are evaluated according to the absorbed dose. For the samples submitted to radiation under oxygen atmosphere it is possible to observe the degradation process with the low levels of the storage modulus. The changes in the degree of crystallinity were verified in all modified samples when compared to the pristine polymer and this behavior was confirmed by DSC analysis. A decrease in the intensity of crystalline peak by X-ray diffraction was observed.

  6. Silica-based cerium (III) chloride nanoparticles prevent the fructose-induced glycation of ?-crystallin and H?O?-induced oxidative stress in human lens epithelial cells.

    PubMed

    Yang, Jin; Cai, Lei; Zhang, Sen; Zhu, Xiangjia; Zhou, Peng; Lu, Yi

    2014-03-01

    This study aimed to investigate whether silica-cerium (III) chloride (CeCl3) nanoparticles could inhibit the formation of advanced glycation end-products (AGEs) and reduce oxidative stress. Silica-CeCl3 nanoparticles were synthesised by adsorption and embedment with micro-silica materials, forming uniform nanoparticles with a diameter of approximately 130 nm. Chaperone activity assays and AGEs formation assays, and intracellular reactive assays were adopted in this study to evaluate CeCl3 nanoparticles effect. UV-visible spectrometry showed that silica-CeCl3 nanoparticles at low concentrations rapidly formed tentatively stable conjugations with ?-crystallin, greatly enhancing the chaperone activity of ?-crystallin. Moreover, silica-CeCl3 nanoparticles markedly inhibited the fructose-induced glycation of ?-crystallin, showing an advantage over the control drugs aminoguanidine and carnosine. Silica-CeCl3 nanoparticles also reduced intracellular reactive oxygen species production and restored glutathione levels in H2O2-treated human lens epithelial cells. These findings suggest that silica-CeCl3 may be used as a novel agent for the prevention of cataractogenesis. PMID:23828754

  7. Role of inducible heat shock protein 70 in radiation-induced cell death

    PubMed Central

    Lee, Su-Jae; Choi, Sun-Ah; Lee, Kang-Hyun; Chung, Hee-Yong; Kim, Tae-Hwan; Cho, Chul-Koo; Lee, Yun-Sil

    2001-01-01

    We previously demonstrated the protective effect of inducible heat shock protein 70 (Hsp70) against gamma radiation. Herein, we extend our studies on the possible role of Hsp70 to ionizing radiation-induced cell cycle regulation. The growth rate of inducible hsp70-transfected cells was 2–3 hours slower than that of control cells. Flow cytometric analysis of cells at G1 phase synchronized by serum starvation also showed the growth delay in the Hsp70-overexpressing cells. In addition, reduced cyclin D1 and Cdc2 levels and increased dephosphorylated phosphoretinoblastoma (pRb) were observed in inducible hsp70-transfected cells, which were probably responsible for the reduction of cell growth. To find out if inducible Hsp70-mediated growth delay affected radiation-induced cell cycle regulation, flow cytometric and molecular analyses of cell cycle regulatory proteins and their kinase were performed. The radiation-induced G2/M arrest was found to be inhibited by Hsp70 overexpression and reduced p21Waf induction and its kinase activity by radiation in the Hsp70-transfected cells. In addition, radiation-induced cyclin A or B1 expressions together with their kinase activities were also inhibited by inducible Hsp70, which represented reduced mitotic cell death. Indeed, hsp70 transfectants showed less induction of radiation-induced apoptosis. When treated with nocodazole, radiation-induced mitotic arrest was inhibited by inducible Hsp70. These results strongly suggested that inducible Hsp70 modified growth delay (increased G1 phase) and reduced G2/M phase arrest, subsequently resulting in inhibition of radiation-induced cell death. PMID:11599569

  8. Radiative recombination mechanisms in individual wurtzite ZnSe nanowires with a defect-free single-crystalline microstructure

    NASA Astrophysics Data System (ADS)

    Saxena, Ankur; Pan, Qi; Ruda, Harry E.

    2013-03-01

    Photoluminescence (PL) spectroscopy performed on arrays of semiconductor nanowires (NWs) suffers from ensemble broadening of PL lines, and fails to separate the PL from NWs of different crystal structures in the ensemble. Even the results on PL from single NWs are not devoid of ambiguity. This is because the influence of structural defects in NWs, such as stacking faults, twin boundaries and dislocations, on their optical spectra cannot be accounted for since the structural characteristics of the same NW remain largely unknown. We performed low-temperature PL spectroscopy on individual wurtzite (WZ) ZnSe NWs, and confirmed a homogeneous single-crystalline microstructure without any extended defects in these NWs, thus excluding any role of structural imperfections in their optical spectra. The luminescence is shown to be dominated solely by native point defects, while no role of extrinsic impurities was found. The radiative recombination is shown to originate from excitons bound to vacancies of Zn (VZn), VZn-complexes, and their phonon replicas. The binding energies of the acceptor-bound excitons, ionization energies of the acceptors, and average number of phonons emitted for shallow donor-VZn acceptor pair related transition were determined. Distinct from previous studies on PL from arrays of ZnSe NWs, this work provides an unambiguous interpretation of the PL spectra and assignment of PL peaks to WZ ZnSe. Narrow excitonic emission of linewidths 2.9 meV indicate excellent optical quality of WZ ZnSe NWs.

  9. Temperature-induced reversible self-assembly of diphenylalanine peptide and the structural transition from organogel to crystalline nanowires

    PubMed Central

    2014-01-01

    Controlling the self-assembly of diphenylalanine peptide (FF) into various nanoarchitectures has received great amounts of attention in recent years. Here, we report the temperature-induced reversible self-assembly of diphenylalanine peptide to microtubes, nanowires, or organogel in different solvents. We also find that the organogel in isopropanol transforms into crystalline flakes or nanowires when the temperature increases. The reversible self-assembly in polar solvents may be mainly controlled by electronic and aromatic interactions between the FF molecules themselves, which is associated with the dissociation equilibrium and significantly influenced by temperature. We found that the organogel in the isopropanol solvent made a unique transition to crystalline structures, a process that is driven by temperature and may be kinetically controlled. During the heating-cooling process, FF preferentially self-assembles to metastable nanofibers and organogel. They further transform to thermodynamically stable crystal structures via molecular rearrangement after introducing an external energy, such as the increasing temperature used in this study. The strategy demonstrated in this study provides an efficient way to controllably fabricate smart, temperature-responsive peptide nanomaterials and enriches the understanding of the growth mechanism of diphenylalanine peptide nanostructures. PMID:25520600

  10. Dose-dependent radiation-induced hypotension in the canine

    SciTech Connect

    Cockerham, L.G.; Hampton, J.D.; Doyle, T.F.

    1986-01-01

    Radiation-induced early transient incapacitation (ETI) is often accompanied by severe systemic hypotension. However, postradiation hypotension does not occur with equal frequency in all species and is not reported with consistency in the canine. In an attempt to clarify the differences in reported canine post-radiation blood pressures, canine systemic blood pressures were determined both before and after exposure to gamma radiation of either 80 or 100 Gy. Data obtained from six sham-radiated beagles and 12 radiated beagles indicated that 100-Gy, whole-body, gamma radiation produced a decrease in systemic mean blood pressure while 80-Gy, whole-body, gamma radiation did not. Analysis of this data could be consistent with a quantal response to a gamma radiation dose between 80 Gy and 100 Gy.

  11. Heavy-ion radiation induced bystander effect in mice

    NASA Astrophysics Data System (ADS)

    Liang, Shujian; Sun, Yeqing; Zhang, Meng; Wang, Wei; Cui, Changna

    2012-07-01

    Radiation-induced bystander effect is defined as the induction of damage in neighboring non-hit cells by signals released from directly-irradiated cells. Recently, Low dose of high LET radiation induced bystander effects in vivo have been reported more and more. It has been indicated that radiation induced bystander effect was localized not only in bystander tissues but also in distant organs. Genomic, epigenetic, metabolomics and proteomics play significant roles in regulating heavy-ion radiation stress responses in mice. To identify the molecular mechanism that underlies bystander effects of heavy-ion radiation, the male mice head were exposed to 2000mGy dose of 12C heavy-ion radiation and the distant organ liver was detected on 1h, 6h, 12h and 24h after radiation, respectively. MSAP was used to monitor the level of polymorphic DNA methylation changes. The results show that heavy-ion irradiate mouse head can induce liver DNA methylation changes significantly. The percent of DNA methylation changes are time-dependent and highest at 6h after radiation. We also prove that the hypo-methylation changes on 1h and 6h after irradiation. But the expression level of DNA methyltransferase DNMT3a is not changed. UPLC/Synapt HDMS G2 was employed to detect the proteomics of bystander liver 1h after irradiation. 64 proteins are found significantly different between treatment and control group. GO process show that six of 64 which were unique in irradiation group are associated with apoptosis and DNA damage response. The results suggest that mice head exposed to heavy-ion radiation can induce damage and methylation pattern changed in distant organ liver. Moreover, our findings are important to understand the molecular mechanism of radiation induced bystander effects in vivo.

  12. Radiation-induced xerostomia: pathophysiology, clinical course and supportive treatment

    Microsoft Academic Search

    H.-J. Guchelaar; A. Vermes; J. H. Meerwaldt

    1997-01-01

    Xerostomia, or oral dryness, is one of the most common complaints experienced by patients who have had radiotherapy of the\\u000a oral cavity and neck region. The hallmarks of radiation-induced damage are acinar atrophy and chronic inflammation of the\\u000a salivary glands. The early response, resulting in atrophy of the secretory cells without inflammation might be due to radiation-induced\\u000a apoptosis. In contrast,

  13. Thermal Modulation of Radiation-Induced DNA Damage Responses

    Microsoft Academic Search

    Joseph L. Roti Roti; Robert P. VanderWaal; Andrei Laszlo

    \\u000a The goal of this review is to delineate the interaction between the DNA damage response and the proteotoxicity induced by\\u000a hyperthermia which leads to increased sensitivity to ionizing radiation. The radiosensitization must come from an interaction\\u000a between the proteotoxicity induced by hyperthermia and DNA damage responses occurring after ionizing radiation. Recently,\\u000a the cellular response to DNA DSB has been described

  14. Radiation-induced myeloid leukemia in murine models

    PubMed Central

    2014-01-01

    The use of radiation therapy is a cornerstone of modern cancer treatment. The number of patients that undergo radiation as a part of their therapy regimen is only increasing every year, but this does not come without cost. As this number increases, so too does the incidence of secondary, radiation-induced neoplasias, creating a need for therapeutic agents targeted specifically towards incidence reduction and treatment of these cancers. Development and efficacy testing of these agents requires not only extensive in vitro testing but also a set of reliable animal models to accurately recreate the complex situations of radiation-induced carcinogenesis. As radiation-induced leukemic progression often involves genomic changes such as rearrangements, deletions, and changes in methylation, the laboratory mouse Mus musculus, with its fully sequenced genome, is a powerful tool in cancer research. This fact, combined with the molecular and physiological similarities it shares with man and its small size and high rate of breeding in captivity, makes it the most relevant model to use in radiation-induced leukemia research. In this work, we review relevant M. musculus inbred and F1 hybrid animal models, as well as methods of induction of radiation-induced myeloid leukemia. Associated molecular pathologies are also included. PMID:25062865

  15. Formation of titanium monoxide (001) single-crystalline thin film induced by ion bombardment of titanium dioxide (110)

    NASA Astrophysics Data System (ADS)

    Pabón, B. M.; Beltrán, J. I.; Sánchez-Santolino, G.; Palacio, I.; López-Sánchez, J.; Rubio-Zuazo, J.; Rojo, J. M.; Ferrer, P.; Mascaraque, A.; Muñoz, M. C.; Varela, M.; Castro, G. R.; de La Fuente, O. Rodríguez

    2015-02-01

    A plethora of technological applications justify why titanium dioxide is probably the most studied oxide, and an optimal exploitation of its properties quite frequently requires a controlled modification of the surface. Low-energy ion bombardment is one of the most extended techniques for this purpose and has been recently used in titanium oxides, among other applications, to favour resistive switching mechanisms or to form transparent conductive layers. Surfaces modified in this way are frequently described as reduced and defective, with a high density of oxygen vacancies. Here we show, at variance with this view, that high ion doses on rutile titanium dioxide (110) induce its transformation into a nanometric and single-crystalline titanium monoxide (001) thin film with rocksalt structure. The discovery of this ability may pave the way to new technical applications of ion bombardment not previously reported, which can be used to fabricate heterostructures and interfaces.

  16. Formation of titanium monoxide (001) single-crystalline thin film induced by ion bombardment of titanium dioxide (110).

    PubMed

    Pabón, B M; Beltrán, J I; Sánchez-Santolino, G; Palacio, I; López-Sánchez, J; Rubio-Zuazo, J; Rojo, J M; Ferrer, P; Mascaraque, A; Muñoz, M C; Varela, M; Castro, G R; Rodríguez de la Fuente, O

    2015-01-01

    A plethora of technological applications justify why titanium dioxide is probably the most studied oxide, and an optimal exploitation of its properties quite frequently requires a controlled modification of the surface. Low-energy ion bombardment is one of the most extended techniques for this purpose and has been recently used in titanium oxides, among other applications, to favour resistive switching mechanisms or to form transparent conductive layers. Surfaces modified in this way are frequently described as reduced and defective, with a high density of oxygen vacancies. Here we show, at variance with this view, that high ion doses on rutile titanium dioxide (110) induce its transformation into a nanometric and single-crystalline titanium monoxide (001) thin film with rocksalt structure. The discovery of this ability may pave the way to new technical applications of ion bombardment not previously reported, which can be used to fabricate heterostructures and interfaces. PMID:25707936

  17. Photo and radiation chemical induced degradation of lignin model compounds

    Microsoft Academic Search

    O. Lanzalunga; M. Bietti

    2000-01-01

    The basic mechanistic aspects of the photo- and radiation chemistry of lignin model compounds (LMCs) are discussed with respect to important processes related to lignin degradation. Several reactions occur after direct irradiation, photosensitized or radiation chemically induced oxidation of LMCs. Direct irradiation studies on LMCs have provided supportive evidence for the involvement of hydrogen abstraction reactions from phenols, ?-cleavage of

  18. Radiation-induced optic neuropathy: A magnetic resonance imaging study

    Microsoft Academic Search

    John Guy; Anthony Mancuso; Roy Beck; Mark L. Moster; Lyn A. Sedwick; Ronald G. Quisling; Albert L. Rhoton; Eugene E. Protzko; Jade Schiffman

    1991-01-01

    Optic neuropathy induced by radiation is an infrequent cause of delayed visual loss that may at times be difficult to differentiate from compression of the visual pathways by recurrent neoplasm. The authors describe six patients with this disorder who experienced loss of vision 6 to 36 months after neurological surgery and radiation therapy. Of the six patients in the series,

  19. Radiation Induced Absorption in Rare Earth Doped Optical Fibers

    Microsoft Academic Search

    M. Lezius; K. Predehl; W. Stower; A. Turler; M. Greiter; Ch. Hoeschen; P. Thirolf; W. Assmann; D. Habs; A. Prokofiev; C. Ekstrom; T. W. Hansch; R. Holzwarth

    2012-01-01

    We have investigated the radiation induced absorption (RIA) of optical fibers with high active ion concentration. Comparing our results to the literature leads us to the conclusion that RIA appears to be only weakly dependent on the rare earth dopant concentration. Instead, co-dopants like Al, Ge, or P and manufacturing processes seem to play the major role for the radiation

  20. Hyperbaric Oxygen Therapy for Radiation-induced Optic Neuropathy

    Microsoft Academic Search

    Richard L Levy; Neil R Miller

    Introduction: Radiation-induced optic neuropathy (RON) is an infrequent but devastating consequence of radiation exposure to the visual pathways, usually following months to years after the treatment of paranasal or intracranial tumours. Hyperbaric oxygen (HBO) therapy is one of several therapies that have been tried for this condition. The purpose of this review is to describe the clinical characteristics of RON,

  1. Countermeasures for space radiation induced adverse biologic effects

    Microsoft Academic Search

    A. R. Kennedy; X. S. Wan

    2011-01-01

    Radiation exposure in space is expected to increase the risk of cancer and other adverse biological effects in astronauts. The types of space radiation of particular concern for astronaut health are protons and heavy ions known as high atomic number and high energy (HZE) particles. Recent studies have indicated that carcinogenesis induced by protons and HZE particles may be modifiable.

  2. Radiation Induced Carcinogenesis; Epidemiology and Mechanisms: A Review

    Microsoft Academic Search

    Stuart Anderson

    Exposure to ionizing radiation has been proven to cause cancer and initiate mutagenesis in human and animal cells. This paper reviews some of the epide- miological data collected over the past 60 years and literature describing the current search for a genetic link to radiation induced carcinogenesis. Increased incidences of Leukemia, Breast Cancer, Lung Cancer, Skin Cancer and Bone Can-

  3. Mechanisms involved in the protection of UV-induced protein inactivation by the corneal crystallin ALDH3A1.

    PubMed

    Estey, Tia; Cantore, Miriam; Weston, Philip A; Carpenter, John F; Petrash, J Mark; Vasiliou, Vasilis

    2007-02-16

    Various lines of evidence have shown that ALDH3A1 (aldehyde dehydrogenase 3A1) plays a critical and multifaceted role in protecting the cornea from UV-induced oxidative stress. ALDH3A1 is a corneal crystallin, which is defined as a protein recruited into the cornea for structural purposes without losing its primary function (i.e. metabolism). Although the primary role of ALDH3A1 in the metabolism of toxic aldehydes has been clearly demonstrated, including the detoxification of aldehydes produced during UV-induced lipid peroxidation, the structural role of ALDH3A1 in the cornea remains elusive. We therefore examined the potential contribution of ALDH3A1 in maintaining the optical integrity of the cornea by suppressing the aggregation and/or inactivation of other proteins through chaperone-like activity and other protective mechanisms. We found that ALDH3A1 underwent a structural transition near physiological temperatures to form a partially unfolded conformation that is suggestive of chaperone activity. Although this structural transition alone did not correlate with any protection, ALDH3A1 substantially reduced the inactivation of glucose-6-phosphate dehydrogenase by 4-hydroxy-2-nonenal and malondialdehyde when co-incubated with NADP(+), reinforcing the importance of the metabolic function of this corneal enzyme in the detoxification of toxic aldehydes. A large excess of ALDH3A1 also protected glucose-6-phosphate dehydrogenase from inactivation because of direct exposure to UVB light, which suggests that ALDH3A1 may shield other proteins from damaging UV rays. Collectively, these data demonstrate that ALDH3A1 can reduce protein inactivation and/or aggregation not only by detoxification of reactive aldehydes but also by directly absorbing UV energy. This study provides for the first time mechanistic evidence supporting the structural role of the corneal crystallin ALDH3A1 as a UV-absorbing constituent of the cornea. PMID:17158879

  4. Lack of Photoprotection Against UVB-Induced Erythema by Immediate Pigmentation Induced by 382 nm Radiation

    Microsoft Academic Search

    Gillian Black; Ezra Matzinger; R. William Gange

    1985-01-01

    Immediate pigment darkening (IPD) was induced on the backs of 11 human volunteers of skin types III and IV by exposing the skin to UVA radiation (382 nm). The minimum erythema dose (MED) of UVB radiation was also determined by exposing sites to graduated doses of 304 nm radiation. The order of exposure of distinct anatomic areas was as follow:

  5. Protection from radiation-induced pneumonitis using cerium oxide nanoparticles.

    PubMed

    Colon, Jimmie; Herrera, Luis; Smith, Joshua; Patil, Swanand; Komanski, Chris; Kupelian, Patrick; Seal, Sudipta; Jenkins, D Wayne; Baker, Cheryl H

    2009-06-01

    In an effort to combat the harmful effects of radiation exposure, we propose that rare-earth cerium oxide (CeO(2)) nanoparticles (free-radical scavengers) protect normal tissue from radiation-induced damage. Preliminary studies suggest that these nanoparticles may be a therapeutic regenerative nanomedicine that will scavenge reactive oxygen species, which are responsible for radiation-induced cell damage. The effectiveness of CeO(2) nanoparticles in radiation protection in murine models during high-dose radiation exposure is investigated, with the ultimate goal of offering a new approach to radiation protection, using nanotechnology. We show that CeO(2) nanoparticles are well tolerated by live animals, and they prevent the onset of radiation-induced pneumonitis when delivered to live animals exposed to high doses of radiation. In the end, these studies provide a tremendous potential for radioprotection and can lead to significant benefits for the preservation of human health and the quality of life for humans receiving radiation therapy. PMID:19285453

  6. Cosmic Microwave Background Radiation Anisotropy Induced by Cosmic Strings

    Microsoft Academic Search

    B. Allen; R. R. Caldwell; E. P. S. Shellard; A. Stebbins; S. Veeraraghavan

    1994-01-01

    We report on a current investigation of the anisotropy pattern induced by cosmic strings on the cosmic microwave background radiation (MBR). We have numerically evolved a network of cosmic strings from a redshift of $Z = 100$ to the present and calculated the anisotropies which they induce. Based on a limited number of realizations, we have compared the results of

  7. Plasma-assisted synthesis and pressure-induced structural transition of single-crystalline SnSe nanosheets

    NASA Astrophysics Data System (ADS)

    Jian Zhang, Affa; Zhu, Hongyang; Wu, Xiaoxin; Cui, Hang; Li, Dongmei; Jiang, Junru; Gao, Chunxiao; Wang, Qiushi; Cui, Qiliang

    2015-06-01

    Two-dimensional tin selenide (SnSe) nanosheets were synthesized using a plasma-assisted direct current arc discharge method. The structural characterization indicates that the nanosheets are single-crystalline with an average thickness of ~25 nm and a lateral dimension of ~500 nm. The high pressure behaviors of the as-synthesized SnSe nanosheets were investigated by in situ high-pressure synchrotron angle-dispersive X-ray diffraction and Raman scattering up to ~30 GPa in diamond anvil cells at room temperature. A second-order isostructural continuous phase transition (Pnma --> Cmcm) was observed at ~7 GPa, which is considerably lower than the transition pressure of bulk SnSe. The reduction of transition pressure is induced by the volumetric expansion with softening of the Poisson ratio and shear modulus. Moreover, the measured zero-pressure bulk modulus of the SnSe nanosheets coincides with bulk SnSe. This abnormal phenomenon is attributed to the unique intrinsic geometry in the nanosheets. The high-pressure bulk modulus is considerably higher than the theoretical value. The pressure-induced morphology change should be responsible for the improved bulk modulus.Two-dimensional tin selenide (SnSe) nanosheets were synthesized using a plasma-assisted direct current arc discharge method. The structural characterization indicates that the nanosheets are single-crystalline with an average thickness of ~25 nm and a lateral dimension of ~500 nm. The high pressure behaviors of the as-synthesized SnSe nanosheets were investigated by in situ high-pressure synchrotron angle-dispersive X-ray diffraction and Raman scattering up to ~30 GPa in diamond anvil cells at room temperature. A second-order isostructural continuous phase transition (Pnma --> Cmcm) was observed at ~7 GPa, which is considerably lower than the transition pressure of bulk SnSe. The reduction of transition pressure is induced by the volumetric expansion with softening of the Poisson ratio and shear modulus. Moreover, the measured zero-pressure bulk modulus of the SnSe nanosheets coincides with bulk SnSe. This abnormal phenomenon is attributed to the unique intrinsic geometry in the nanosheets. The high-pressure bulk modulus is considerably higher than the theoretical value. The pressure-induced morphology change should be responsible for the improved bulk modulus. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr02131f

  8. Strain-induced partially flat band, helical snake states and interface superconductivity in topological crystalline insulators

    NASA Astrophysics Data System (ADS)

    Tang, Evelyn; Fu, Liang

    2014-12-01

    Topological crystalline insulators in IV-VI compounds host novel topological surface states consisting of multi-valley massless Dirac fermions at low energy. Here we show that strain generically acts as an effective gauge field on these Dirac fermions and creates pseudo-Landau orbitals without breaking time-reversal symmetry. We predict the realization of this phenomenon in IV-VI semiconductor heterostructures, due to a naturally occurring misfit dislocation array at the interface that produces a periodically varying strain field. Remarkably, the zero-energy Landau orbitals form a flat band in the vicinity of the Dirac point, and coexist with a network of snake states at higher energy. We propose that the high density of states of this flat band gives rise to interface superconductivity observed in IV-VI semiconductor multilayers at unusually high temperatures, with non-Bardeen-Cooper-Schrieffer behaviour. Our work demonstrates a new route to altering macroscopic electronic properties to achieve a partially flat band, and provides a starting point for realizing novel correlated states of matter.

  9. Understanding the Mechanism of Enzyme-Induced Formation of Lyotropic Liquid Crystalline Nanoparticles.

    PubMed

    Hong, Linda; Salentinig, Stefan; Hawley, Adrian; Boyd, Ben J

    2015-06-23

    Liquid crystalline nanoparticles have shown great potential for application in fields of drug delivery and agriculture. However, optimized approaches to generating these dispersions have long been sought after. This study focused on understanding the mechanism of formation of cubosomes during the recently reported enzymatic approach and extending the approach to alternative lipid types other than phytantriol. The chain length of digestible lipids was found to influence the effectiveness of triglycerides in disrupting the equilibrium cubic phase structure to form the emulsion precursor. In general, a greater hydrophobicity of the triglyceride required a lower concentration to inhibit liquid crystal structure formation. Selachyl alcohol was also examined due to its nondigestible trait and ability to form the inverted hexagonal phase. Digestion of its precursor emulsion formed hexosomes analogous to the phytantriol-based systems. Finally, the assumption that fatty acids liberated during digestion needed to partition out of the nondigestible lipids for the re-formation of the phase structure was found to be untrue. Their ionization state, however, did have an effect on the resulting nanostructure, and this unique property could potentially provide a useful attribute for oral drug delivery systems. PMID:26029994

  10. The radiation-induced chemistry in solid xenon matrices

    NASA Astrophysics Data System (ADS)

    Feldman, V. I.; Kobzarenko, A. V.; Orlov, A. Y.; Sukhov, F. F.

    2012-08-01

    The paper presents an overview of recent studies of the radiation-chemical transformations of guest molecules in solid xenon induced by fast electrons and x-ray irradiation. Specific features of the experimental approach based on the combination of matrix isolation IR and EPR spectroscopy are briefly outlined (with a particular emphasis on monoisotopic and isotopically enriched xenon matrices). The results reveal rich and diverse radiation-induced chemistry in solid xenon, which is considered in the following major aspects: (1) matrix-induced and matrix-assisted transformations of the primary guest radical cations; (2) production and dynamics of hydrogen atoms; (3) formation of xenon hydrides. Finally, preliminary results on the radiation-induced generation of oxygen atoms and ions in solid xenon are presented.

  11. Radio frequency radiation-induced hyperthermia using Si nanoparticle-based sensitizers for mild cancer therapy

    NASA Astrophysics Data System (ADS)

    Tamarov, Konstantin P.; Osminkina, Liubov A.; Zinovyev, Sergey V.; Maximova, Ksenia A.; Kargina, Julia V.; Gongalsky, Maxim B.; Ryabchikov, Yury; Al-Kattan, Ahmed; Sviridov, Andrey P.; Sentis, Marc; Ivanov, Andrey V.; Nikiforov, Vladimir N.; Kabashin, Andrei V.; Timoshenko, Victor Yu

    2014-11-01

    Offering mild, non-invasive and deep cancer therapy modality, radio frequency (RF) radiation-induced hyperthermia lacks for efficient biodegradable RF sensitizers to selectively target cancer cells and thus avoid side effects. Here, we assess crystalline silicon (Si) based nanomaterials as sensitizers for the RF-induced therapy. Using nanoparticles produced by mechanical grinding of porous silicon and ultraclean laser-ablative synthesis, we report efficient RF-induced heating of aqueous suspensions of the nanoparticles to temperatures above 45-50°C under relatively low nanoparticle concentrations (<1 mg/mL) and RF radiation intensities (1-5 W/cm2). For both types of nanoparticles the heating rate was linearly dependent on nanoparticle concentration, while laser-ablated nanoparticles demonstrated a remarkably higher heating rate than porous silicon-based ones for the whole range of the used concentrations from 0.01 to 0.4 mg/mL. The observed effect is explained by the Joule heating due to the generation of electrical currents at the nanoparticle/water interface. Profiting from the nanoparticle-based hyperthermia, we demonstrate an efficient treatment of Lewis lung carcinoma in vivo. Combined with the possibility of involvement of parallel imaging and treatment channels based on unique optical properties of Si-based nanomaterials, the proposed method promises a new landmark in the development of new modalities for mild cancer therapy.

  12. Radiation-induced bystander signalling in cancer therapy

    PubMed Central

    Prise, Kevin M.; O'Sullivan, Joe M.

    2010-01-01

    Our understanding of how radiation kills normal and tumour cells has been based on an intimate knowledge of the direct induction of DNA damage and its cellular consequences. What has become clear is that, as well as responses to direct DNA damage, cell–cell signalling — known as the bystander effect — mediated through gap junctions and inflammatory responses may have an important role in the response of cells and tissues to radiation exposure and also chemotherapy agents. This Review outlines the key aspects of radiation-induced intercellular signalling and assesses its relevance for existing and future radiation-based therapies. PMID:19377507

  13. Radiation-induced malignant and atypical peripheral nerve sheath tumors

    SciTech Connect

    Foley, K.M.; Woodruff, J.M.; Ellis, F.T.; Posner, J.B.

    1980-04-01

    The reported peripheral nerve complications of therapeutic irradiation in humans include brachial and lumbar plexus fibrosis and cranial and peripheral nerve atrophy. We have encountered 9 patients with malignant (7) and atypical (2) peripheral nerve tumors occurring in an irradiated site suggesting that such tumors represent another delayed effect of radiation treatment on peripheral nerve. In all instances the radio-theray was within an acceptable radiation dosage, yet 3 patients developed local radiation-induced skin and bony abnormalities. The malignant peripheral nerve sheath tumors developed only in the radiation port. Animal studies support the clinical observation that malignant peripheral nerve sheath tumors can occur as a delayed effect of irradiation.

  14. Temporal and spatial changes in VEGF, ?A- and ?B-crystallin expression in a mouse model of oxygen-induced retinopathy

    PubMed Central

    Shi, Yi; Su, Chang; Wang, Jian-Tao; Du, Bei; Dong, Li-Jie; Liu, Ai-Hua; Li, Xiao-Rong

    2015-01-01

    Objective: Retinal neovascularization is an iconic change in retinopathies. Vascular Endothelial Growth Factor (VEGF) and ?-crystallins have been identified to mediate the pathogenesis of retinopathy. However, the special and temporal changes in their expression associated with retinal neovascularization have not yet been determined. Therefore, we examined the expression and distribution of VEGF, ?A- and ?B-crystallins in the retina using a mouse model of oxygen-induced retinopathy (OIR). Methods: 90 C57/BL mice were randomly divided into the OIR and control groups. The OIR group at postnatal day 7 (P7) were kept at high oxidation state (75 ± 5%) for 5 days before returned to normal environment. Retinal tissue was cut into sections. Oxygen induced retinal neovascularization and vascular structural changes were evaluated using retinal fluorescein angiography. The number of endothelial cell nuclei breaking through the retinal internal limiting membrane was counted after H&E staining. The mRNA expression levels of VEGF, ?A- and ?B-crystallins in the mouse retina were determined using real-time RT-PCR. The distribution of ?A- and ?B-crystallins in the retina was detected by fluorescent immunohistochemistry staining. Results: Oxygen induction triggered new blood vessel formation in the retina and impaired the structure of the retinal vascular network. The number of endothelial cell nuclei breaking through the retinal internal limiting membrane was significantly increased in the OIR group compared to the control group at P13, P17 and P21 (P < 0.01), reaching the peak on P17. The expression levels of VEGF, ?A- and ?B-crystalllins were also significantly different between the OIR and control groups. VEGF expression was highest on P15, ?A-crystallin expression was highest on P17, whereas ?B-crystallin expression kept increasing during the time frame of our study. Both ?A- and ?B-crystallins were expressed in the ganglion cell layer and the inner nuclear cell layer. While ?A- and ?B-crystallins were only located on the cell membrane in the outer ganglion cell layer, they were observed both on the cell membrane and in the cytoplasm in the inner layer of cells. Conclusion: Using our mouse model of oxygen-induced retinopathy, we showed that the expression patterns of VEGF, ?A- and ?B-crystallins during retinal neovascularization in both spatially and temporally manners, providing significant insights into the molecular mechanisms of retinopathy and the associated neovascularization.

  15. Dynamics of negative bias thermal stress-induced threshold voltage shifts in indium zinc oxide transistors: impact of the crystalline structure on the activation energy barrier

    NASA Astrophysics Data System (ADS)

    Oh, Seungha; Yang, Bong Seob; Kim, Yoon Jang; Choi, Yu Jin; Kim, Un Ki; Han, Sang Jin; Lee, Hong Woo; Kim, Hyuk Jin; Kim, Sungmin; Kyeong Jeong, Jae; Kim, Hyeong Joon

    2014-04-01

    The kinetics of the negative bias thermal stress (NBTS)-induced Vth variations of indium zinc oxide (IZO) transistors with different crystallographic qualities were examined based on the stretched-exponential formalism. A poly-crystalline IZO device had a 0.64 eV lower activation barrier energy than an amorphous IZO device under NBTS conditions. This was attributed to the difference in the migration energy barrier between poly-crystalline and amorphous IZO films. For the recovery process, however, the activation energy barriers (˜0.75 eV) were independent of the crystal structure. A plausible microscopic mechanism to account for the experimental results is proposed.

  16. On the strain-induced structural evolution upon uniaxial stretching of Poly(VinyliDene Fluoride): influence of secondary crystals and crystalline relaxation

    NASA Astrophysics Data System (ADS)

    Defebvin, Juliette; Barrau, Sophie; Stoclet, Grégory; Lefebvre, Jean-Marc; Polymer Engineering Science Team

    2015-03-01

    Development of more efficient piezoelectric devices tends to innovate and create materials able to combine flexibility and electro-mechanical conversion. Poly(vinylidene fluoride) (PVDF) is a semi-crystalline polymer that exhibits interesting piezoelectric properties. Besides PVDF is able to convert a mechanical solicitation into an electric energy and vice versa. However these physical properties are highly dependent on the polymer crystal structure. PVDF presents at least two main crystalline forms. The most common phase is the ?-phase that is non-polar. On the other hand, the ? phase is the most polar one and it can be obtained by a stretching of the ?-phase. Knowing the influence of the drawing conditions on the strain-induced structural evolution is thus of prime interest. To assess this point the strain-induced structural evolution of PVDF, stretched under different conditions, has been followed in-situ by means of WAXS/SAXS experiments. As a main result, this study shows that drawing conditions strongly affect both the ? to ? phase conversion degree and the crystalline morphology. Moreover the key role played by the crystalline relaxation of PVDF on the strain-induced structural evolution is also highlighted for the first time.

  17. Radioprotectors and Mitigators of Radiation-Induced Normal Tissue Injury

    PubMed Central

    Cotrim, Ana P.; Hyodo, Fuminori; Baum, Bruce J.; Krishna, Murali C.; Mitchell, James B.

    2010-01-01

    Radiation is used in the treatment of a broad range of malignancies. Exposure of normal tissue to radiation may result in both acute and chronic toxicities that can result in an inability to deliver the intended therapy, a range of symptoms, and a decrease in quality of life. Radioprotectors are compounds that are designed to reduce the damage in normal tissues caused by radiation. These compounds are often antioxidants and must be present before or at the time of radiation for effectiveness. Other agents, termed mitigators, may be used to minimize toxicity even after radiation has been delivered. Herein, we review agents in clinical use or in development as radioprotectors and mitigators of radiation-induced normal tissue injury. Few agents are approved for clinical use, but many new compounds show promising results in preclinical testing. PMID:20413641

  18. A model of radiation-induced myelopoiesis in space.

    PubMed

    Esposito, R D; Durante, M; Gialanella, G; Grossi, G; Pugliese, M; Scampoli, P; Jones, T D

    2001-01-01

    Astronauts' radiation exposure limits are based on experimental and epidemiological data obtained on Earth. It is assumed that radiation sensitivity remains the same in the extraterrestrial space. However, human radiosensitivity is dependent upon the response of the hematopoietic tissue to the radiation insult. It is well known that the immune system is affected by microgravity. We have developed a mathematical model of radiation-induced myelopoiesis which includes the effect of microgravity on bone marrow kinetics. It is assumed that cellular radiosensitivity is not modified by the space environment, but repopulation rates of stem and stromal cells are reduced as a function of time in weightlessness. A realistic model of the space radiation environment, including the HZE component, is used to simulate the radiation damage. A dedicated computer code was written and applied to solar particle events and to the mission to Mars. The results suggest that altered myelopoiesis and lymphopoiesis in microgravity might increase human radiosensitivity in space. PMID:11771552

  19. Radiation-induced emesis in monkeys

    SciTech Connect

    Mattsson, J.L.; Yochmowitz, M.G.

    1980-04-01

    To determine the emesis ED/sub 50/ for /sup 60/Co radiation, 15 male rhesus monkeys were exposed to whole-body radiation doses ranging from 350 to 550 rad midline tissue dose. An up-and-down sequence of exposures was used. Step size between doses was 50 rad, and dose rate was 20 rad/min. There had been no access to food for 1 to 2 h. The ED/sub 50/ +- SE was found to be 446 +- 27 rad. To determine the effect of motion on emesis ED/sub 50/, six more monkeys were exposed to /sup 60/Co radiation as above, except that the chair in which they were seated was oscillated forward and backward 5 to 15/sup 0/ (pitch axis) at a variable rate not exceeding 0.3 Hz. Radioemesis ED/sub 50/ +- SE with motion was 258 +- 19 rad, a value significantly lower (P < 0.01) than for stationary monkeys.

  20. Synchrotron Microbeam Radiation Therapy induces hypoxia in intracerebral gliosarcoma but not in the normal brain

    E-print Network

    Paris-Sud XI, Université de

    Synchrotron Microbeam Radiation Therapy induces hypoxia in intracerebral gliosarcoma University, 85748 Garching, Germany Key words: Synchrotron Microbeam Radiation Therapy - Brain Tumors. 2013 3 Introduction Synchrotron microbeam radiation therapy (MRT) uses high radiation doses delivered

  1. Hyperprolactinemia from radiation-induced hypothalamic hypopituitarism

    SciTech Connect

    Corkill, G.; Hanson, F.W.; Gold, E.M.; White, V.A.

    1980-01-01

    In 1975 Samaan et al., described the effects of radiation damage of the hypothalamus in 15 patients with head and neck cancer. Shalet et al., in 1977 described endocrine morbidity in adults who as children had been irradiated for brain tumors. This report describes instances of hyperprolactinemia and associated hypothalamic, pituitary, and thyroid dysfunction following irradiation of a young adult female for brain neoplasia.

  2. Radiation-induced degradation of sodium alginate

    Microsoft Academic Search

    Naotsugu Nagasawa; Hiroshi Mitomo; Fumio Yoshii; Tamikazu Kume

    2000-01-01

    Alginates were irradiated as solids or in aqueous solution with Co60 gamma rays in the dose range of 20 to 500 kGy to investigate the effect of radiation on alginates. Degradation was observed both in the solid state and solution. The degradation in solution was remarkably greater than that in the solid. For example, the molecular weight of alginate in

  3. Radiation-induced biomarkers for the detection and assessment of absorbed radiation doses

    PubMed Central

    Rana, Sudha; Kumar, Raj; Sultana, Sarwat; Sharma, Rakesh Kumar

    2010-01-01

    Radiation incident involving living organisms is an uncommon but a very serious situation. The first step in medical management including triage is high-throughput assessment of the radiation dose received. Radiation exposure levels can be assessed from viability of cells, cellular organelles such as chromosome and different intermediate metabolites. Oxidative damages by ionizing radiation result in carcinogenesis, lowering of the immune response and, ultimately, damage to the hematopoietic system, gastrointestinal system and central nervous system. Biodosimetry is based on the measurement of the radiation-induced changes, which can correlate them with the absorbed dose. Radiation biomarkers such as chromosome aberration are most widely used. Serum enzymes such as serum amylase and diamine oxidase are the most promising biodosimeters. The level of gene expression and protein are also good biomarkers of radiation. PMID:21829314

  4. Modulation of Radiation-Induced Apoptosis by Thiolamines

    NASA Technical Reports Server (NTRS)

    Warters, R. L.; Roberts, J. C.; Wilmore, B. H.; Kelley, L. L.

    1997-01-01

    Exposure to the thiolamine radioprotector N-(2-mercaptoethyl)-1,3-propanediamine (WR-1065) induced apoptosis in the mouse TB8-3 hybridoma after 60-minute (LD(sub50) = 4.5mM) or during a 20-hour (LD(sub50) = 0.15 mM) exposure. In contrast, a 20-hour exposure to 17 mM L-cysteine or 10 mM cysteamine was required to induce 50 percent apoptosis within 20 hours. Apoptosis was not induced by either a 60-minute or 20-hour exposure to 10 mM of the thiazolidime prodrugs ribose-cysteine (RibCys) or ribose-cysteamine (RibCyst). Thiolamine-induced apoptosis appeared to be a p53-independent process since it was induced by WR-1065 exposure in human HL60 cells. Exposure to WR-1065 (4mM for 15 minutes) or cysteine (10mM for 60 minutes) before and during irradiation protected cells against the induction of both DNA double-strand breaks and apoptosis, while exposure to RibCys (10 mM for 3 hours) did not. Treatment with either WR-1065, cysteine, RibCys or RibCyst for 60 minutes beginning 60 minutes after irradiation did not affect the level of radiation-induced apoptosis. In contrast, treatment with either cysteine, cysteamine or RibCys for 20 hours beginning 60 minutes after irradiation enhanced radiation-induced apoptosis. Similar experiments could not be conducted with WR-1065 because of its extreme toxicity. Our results indicate that thiolamine enhancement of radiation-induced apoptosis is not involved in their previously reported capacity to reduce radiation-induced mutations.

  5. Contribution of radiation-induced, nitric oxide-mediated bystander effect to radiation-induced adaptive response.

    NASA Astrophysics Data System (ADS)

    Matsumoto, H.; Ohnishi, T.

    There has been a recent upsurge of interest in radiation-induced adaptive response and bystander effect which are specific modes in stress response to low-dose low-dose rate radiation Recently we found that the accumulation of inducible nitric oxide NO synthase iNOS in wt p53 cells was induced by chronic irradiation with gamma rays followed by acute irradiation with X-rays but not by each one resulting in an increase in nitrite concentrations of medium It is suggested that the accumulation of iNOS may be due to the depression of acute irradiation-induced p53 functions by pre-chronic irradiation In addition we found that the radiosensitivity of wt p53 cells against acute irradiation with X-rays was reduced after chronic irradiation with gamma rays This reduction of radiosensitivity of wt p53 cells was nearly completely suppressed by the addition of NO scavenger carboxy-PTIO to the medium This reduction of radiosensitivity of wt p53 cells is just radiation-induced adaptive response suggesting that NO-mediated bystander effect may considerably contribute to adaptive response induced by radiation

  6. The mechanisms of radiation-induced bystander effect.

    PubMed

    Najafi, M; Fardid, R; Hadadi, Gh; Fardid, M

    2014-12-01

    The radiation-induced bystander effect is the phenomenon which non-irradiated cells exhibit effects along with their different levels as a result of signals received from nearby irradiated cells. Responses of non-irradiated cells may include changes in process of translation, gene expression, cell proliferation, apoptosis and cells death. These changes are confirmed by results of some In-Vivo studies. Most well-known important factors affecting radiation-induced bystander effect include free radicals, immune system factors, expression changes of some genes involved in inflammation pathway and epigenetic factors. PMID:25599062

  7. Panretinal photocoagulation for radiation-induced ocular ischemia

    SciTech Connect

    Augsburger, J.J.; Roth, S.E.; Magargal, L.E.; Shields, J.A.

    1987-08-01

    We present preliminary findings on the effectiveness of panretinal photocoagulation in preventing neovascular glaucoma in eyes with radiation-induced ocular ischemia. Our study group consisted of 20 patients who developed radiation-induced ocular ischemia following cobalt-60 plaque radiotherapy for a choroidal or ciliary body melanoma. Eleven of the 20 patients were treated by panretinal photocoagulation shortly after the diagnosis of ocular ischemia, but nine patients were left untreated. In this non-randomized study, the rate of development of neovascular glaucoma was significantly lower (p = 0.024) for the 11 photocoagulated patients than for the nine who were left untreated.

  8. The Mechanisms of Radiation-Induced Bystander Effect

    PubMed Central

    Najafi, M; Fardid, R; Hadadi, Gh; Fardid, M

    2014-01-01

    The radiation-induced bystander effect is the phenomenon which non-irradiated cells exhibit effects along with their different levels as a result of signals received from nearby irradiated cells. Responses of non-irradiated cells may include changes in process of translation, gene expression, cell proliferation, apoptosis and cells death. These changes are confirmed by results of some In-Vivo studies. Most well-known important factors affecting radiation-induced bystander effect include free radicals, immune system factors, expression changes of some genes involved in inflammation pathway and epigenetic factors. PMID:25599062

  9. Simple method to demonstrate radiation-inducible radiation resistance in microbial cells

    SciTech Connect

    Tan, S.T.; Maxcy, R.B.

    1986-01-01

    A simple method for detection of radiation-inducible radiation resistance was developed by irradiating aliquots (0.01 ml) of cell suspension on agar plates. Part of each experimental plate was subjected to an induction treatment, and subsequent radiation resistance was compared with that of untreated cells on the same plate. The UV radiation resistance of a Micrococcus sp. was increased approximately 1.6 times by an induction treatment. This simple procedure of irradiating cells in a fixed position on agar avoided washing, centrifugation, and cell enumeration required in traditional methods.

  10. Mitigation of radiation induced surface contamination

    DOEpatents

    Klebanoff, Leonard E. (Dublin, CA); Stulen, Richard H. (Livermore, CA)

    2003-01-01

    A process for mitigating or eliminating contamination and/or degradation of surfaces having common, adventitious atmospheric contaminants adsorbed thereon and exposed to radiation. A gas or a mixture of gases is introduced into the environment of a surface(s) to be protected. The choice of the gaseous species to be introduced (typically a hydrocarbon gas, water vapor, or oxygen or mixtures thereof) is dependent upon the contaminant as well as the ability of the gaseous species to bind to the surface to be protected. When the surface and associated bound species are exposed to radiation reactive species are formed that react with surface contaminants such as carbon or oxide films to form volatile products (e.g., CO, CO.sub.2) which desorb from the surface.

  11. Radiation induced growth of micro crystallites

    SciTech Connect

    Meisel, D.

    1991-01-01

    Generation of colloidal particles during the radiolysis of aqueous solutions was already observed in the early days of radiation chemistry. Systematic studies using radiation chemistry techniques as synthetic tools in the preparation of colloidal particles, primarily metallic particles, were begun approximately a decade ago in conjunction since they were found to catalyze multi-electron redox processes. A large number of metallic colloidal particles were then synthesized, including silver, gold, platinum, iridium, nickel, cadmium, and others. More recently, attention has turned to semiconductor colloidal particles. The stimulus to these studies is the observation of quantum size effects in small semiconductor particles that exhibit hybrid properties between those of the molecular species and the solid state bulk material. In the following we discuss our own observations on the evolution of semiconductor particles whose growth has been initiated by pulse radiolysis. 13 refs., 2 figs.

  12. Radiation-induced charge dynamics in dielectrics

    SciTech Connect

    Labonte, K.

    1982-12-01

    A general physical model is presented for the analysis of charge dynamics in dielectrics exposed to ionizing radiation. Discrete trap levels, recombination between trapped and free carriers, trapping and detrapping events, and the mobility of positive and negative charge carriers are included in the theory. This model is applied to electron beam irradiated Teflon FEP foils and results for various boundary conditions are compared with experimental data from a split Faraday cup arrangement.

  13. Radiation induced heart disease in hypertensive rats

    SciTech Connect

    Lauk, S.; Trott, K.R.

    1988-01-01

    Spontaneously hypertensive Wistar rats were given single doses of X rays to their heart. Irradiation decreased the blood pressure before any myocardial radiation damage was apparent. Male rats, which were more hypertensive than female rats, had a shorter survival time after local heart irradiation than female rats. Antihypertensive treatment with hydralazine did not increase the survival time. It is considered that myocardial hypertrophy is the cause of the increased susceptibility of spontaneously hypertensive rats to local heart irradiation.

  14. Radiation Induced Conductivity in Polyethylene and Teflon

    Microsoft Academic Search

    R. A. Meyer; F. L. Bouquet; R. S. Alger

    1956-01-01

    The conductivity induced in polyethylene and Teflon by bombardment with x-rays from a 2-Mev Van de Graaff and gamma rays from Co60 has been investigated as a function of time, temperature, geometry, exposure rate, and applied electric field. Within the range of the variables studied, the observed photocurrents were directly proportional to the exposure rate and the applied electric field.

  15. Factors that modify risks of radiation-induced cancer

    SciTech Connect

    Fabrikant, J.I. (Univ. of California, Berkeley (USA))

    1990-07-01

    The collective influence of biologic, physical, and other factors that modify risks of radiation-induced cancer introduces uncertainties and assumptions that limit precision of estimates of human cancer risk that can be calculated for populations exposed to low-dose radiation. The important biologic characteristics include the tissue sites and cell types, baseline cancer incidence, latent periods, time-to-tumor recognition, and individual host (e.g., age and sex) and competing etiologic influences. Physical factors include radiation dose, dose rate, and radiation quality. Statistical factors include time-response projection models, risk coefficients, and dose-response relationships. Sources that modify risk also include other carcinogens and biologic factors (e.g., hormonal conditions, immune status, hereditary factors). Discussion includes examples of known influences that modify radiation-associated cancer risks and how they have been dealt with in the risk-estimation process, including extrapolation to low doses, use of relative risk models, and other uncertainties.

  16. Pressure-induced depolarization and resonance in Raman scattering of single-crystalline boron carbide

    SciTech Connect

    Guo Junjie; Zhang Ling; Fujita, Takeshi; Chen Mingwei [WPI Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Goto, Takashi [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan)

    2010-02-01

    We report polarized and resonant Raman scattering of single-crystal boron carbide (B{sub 4}C) at high pressures. Significant intensity enhancements of 270 and 1086 cm{sup -1} Raman bands of B{sub 4}C have been observed at quasihydrostatic pressures higher than approx20 GPa. The pressure-induced intensity change of the 1086 cm{sup -1} band is mainly due to the resonance between excitation energy and electronic transition, whereas the intensity change of 270 cm{sup -1} band is caused by the depolarization effect. Importantly, the first-order phase transition has not been found at high quasihydrostatic pressures and all the Raman intensity changes along with the corresponding high-pressure lattice distortion can be recovered during unloading.

  17. Interleukin-32 Positively Regulates Radiation-Induced Vascular Inflammation

    SciTech Connect

    Kobayashi, Hanako; Yazlovitskaya, Eugenia M. [Department of Radiation Oncology, Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, TN (United States); Lin, P. Charles [Department of Radiation Oncology, Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, TN (United States); Department of Cancer Biology, Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, TN (United States); Department of Cell and Development Biology, Vanderbilt-Ingram Cancer Center, Vanderbilt University Medical Center, Nashville, TN (United States)], E-mail: Charles.lin@vanderbilt.edu

    2009-08-01

    Purpose: To study the role of interleukin-32 (IL-32), a novel protein only detected in human tissues, in ionizing radiation (IR)-induced vascular inflammation. Methods and Materials: Irradiated (0-6 Gy) human umbilical vein endothelial cells treated with or without various agents-a cytosolic phospholipase A2 (cPLA2) inhibitor, a cyclooxygenase-2 (Cox-2) inhibitor, or lysophosphatidylcholines (LPCs)-were used to assess IL-32 expression by Northern blot analysis and quantitative reverse transcriptase-polymerase chain reaction. Expression of cell adhesion molecules and leukocyte adhesion to endothelial cells using human acute monocytic leukemia cell line (THP-1) cells was also analyzed. Results: Ionizing radiation dramatically increased IL-32 expression in vascular endothelial cells through multiple pathways. Ionizing radiation induced IL-32 expression through nuclear factor {kappa}B activation, through induction of cPLA2 and LPC, as well as induction of Cox-2 and subsequent conversion of arachidonic acid to prostacyclin. Conversely, blocking nuclear factor {kappa}B, cPLA2, and Cox-2 activity impaired IR-induced IL-32 expression. Importantly, IL-32 significantly enhanced IR-induced expression of vascular cell adhesion molecules and leukocyte adhesion on endothelial cells. Conclusion: This study identifies IL-32 as a positive regulator in IR-induced vascular inflammation, and neutralization of IL-32 may be beneficial in protecting from IR-induced inflammation.

  18. Chemoprevention of Radiation Induced Rat Mammary Neoplasms

    NASA Technical Reports Server (NTRS)

    Huso, David L.

    1999-01-01

    Radiations encountered in space include protons and heavy ions such as iron as well as their secondaries. The relative biological effect (RBE) of these ions is not known, particularly at the doses and dose-rates expected for planetary missions. Neutrons, are not particularly relevant to space travel, but have been found experimentally to have an increase in their RBE with decreasing dose. If a similar trend of increasing RBE with decreasing dose is present for heavy ions and protons during irradiation in space, the small doses received during space travel could potentially have substantial carcinogenic risk. Clearly more investigation of the effects of heavy ions and protons is needed before accurate risk assessment for prolonged travel in space can be done. One means to mitigate the increased risk of cancer due to radiation exposure in space is by developing effective countermeasures that can reduce the incidence of tumor development. Tamoxifen has recently been shown to be an effective chemopreventive agent in both animal models and humans for the prevention of mammary tumors. Tamoxifen is a unique drug, with a highly specific mechanism of action affecting a specific radiation-sensitive population of epithelial cells in the mammary gland. In human studies, the annual incidence of a primary tumor in the contralateral breast of women with previous breast cancer is about 8 per 1000, making them an exceedingly high-risk group for the development of breast cancer. In this high risk group, treated with tamoxifen, daily, for 2 years, the incidence of a new primary tumor in the contralateral breast was approximately one third of that noted in the non-tamoxifen treatment group. Tamoxifen antagonizes the action of estrogen by competing for the nuclear receptor complex thereby altering the association of the receptor complex and nuclear binding sites. Its effects in reducing the development of breast cancer could be accomplished by controlling clinically undetectable microcancers, arresting preneoplastic lesions, or correcting abnormal environments which predispose to high risk of malignant transformation.

  19. Magnetically induced ferroelectricity in single crystalline Lu2CoMnO6

    NASA Astrophysics Data System (ADS)

    Chikara, Shalinee; Singleton, John; Choi, Hwan Young; Lee, Nara; Choi, Young J.; Zapf, Vivien

    2015-03-01

    We present pulsed-magnetic-field measurements on Lu2CoMnO6 single crystals. We are able to resolve electric polarization in single crystals for the first time. The bulk hysteretic magnetization couples to the electric polarization resulting in coupled, hysteretic, multiferroic behavior. The alternating S = 3 / 2 Co2+ and Mn4+ ions sit in a corner-sharing octahedral oxygen environment. The Co-Mn-Co-Mn spins order in an up-up-down-down (uudd) arrangement along the c - axis. The ferroelectricity was believed to originate from the exchange striction due to the uudd spin arrangement. However, recent dielectric measurements suggest polarization along the b - not the c - axis. Our results confirm that ferroelectricity is indeed observed along the b - axis and not along the uudd spin-ordering direction. This indicates a different origin for the multiferroic behavior. The frustrated spin system displays an incommensurate long-wavelength modulation that may play a role in inducing ferroelectricity.

  20. Single crystalline BaTiO3 thin films synthesized using ion implantation induced layer transfer

    NASA Astrophysics Data System (ADS)

    Park, Young-Bae; Diest, Kenneth; Atwater, Harry A.

    2007-10-01

    Layer transfer of BaTiO3 thin films onto silicon-based substrates has been investigated. Hydrogen and helium ions were co-implanted to facilitate ion-implantation-induced layer transfer of films from BaTiO3 single crystals. From thermodynamic equilibrium calculations, we suggest that the dominant species during cavity nucleation and growth are H2, H+, H2O, Ba2+ and Ba-OH, and that the addition of hydrogen to the Ba-Ti-O system can effectively suppress volatile oxide formation during layer transfer and subsequent annealing. After ion implantation, BaTiO3 layers contain microstructural defects and hydrogen precipitates in the lattice, but after layer transfer, the single crystal is found to be stoichiometric. Using direct wafer bonding and layer splitting, single crystal BaTiO3 thin films were transferred onto amorphous Si3N4 and Pt substrates. Micro-Raman spectroscopy indicated that the density of defects generated by ion implantation in BaTiO3 can be significantly reduced during post-transfer annealing, returning the transferred layer to its single crystal state. Characterization using piezoresponse force microscopy shows that the layer transferred thin films are ferroelectric, with domain structures and piezoresponse characteristics similar to that of bulk crystals.

  1. Paclitaxel-carboplatin induced radiation recall colitis.

    PubMed

    Kundak, Isil; Oztop, Ilhan; Soyturk, Mujde; Ozcan, Mehmet Ali; Yilmaz, Ugur; Meydan, Nezih; Gorken, Ilknur Bilkay; Kupelioglu, Ali; Alakavuklar, Mehmet

    2004-01-01

    Some chemotherapeutic agents can "recall" the irradiated volumes by skin or pulmonary reactions in cancer patients who previously received radiation therapy. We report a recall colitis following the administration of paclitaxel-containing regimen in a patient who had been irradiated for a carcinoma of the uterine cervix. A 63-year-old woman underwent a Wertheim operation because of uterine cervix carcinoma. After 8 years of follow-up, a local recurrence was observed and she received curative external radiotherapy (45 Gy) to the pelvis. No significant adverse events were observed during the radiotherapy. Approximately one year later, she was hospitalized because of metastatic disease with multiple pulmonary nodules, and a chemotherapy regimen consisting of paclitaxel and carboplatin was administered. The day after the administration of chemotherapy the patient had diarrhea and rectal bleeding. Histological examination of the biopsy taken from rectal hyperemic lesions showed a radiation colitis. The symptoms reappeared after the administration of each course of chemotherapy and continued until the death of the patient despite the interruption of the chemotherapy. In conclusion, the probability of recall phenomena should be kept in mind in patients who received previously with pelvic radiotherapy and treated later with cytotoxic chemotherapy. PMID:15237594

  2. Radiation-induced endometriosis in Macaca mulatta

    SciTech Connect

    Fanton, J.W.; Golden, J.G. (USAF School of Aerospace Medicine, Brooks AFB, TX (USA))

    1991-05-01

    Female rhesus monkeys received whole-body doses of ionizing radiation in the form of single-energy protons, mixed-energy protons, X rays, and electrons. Endometriosis developed in 53% of the monkeys during a 17-year period after exposure. Incidence rates for endometriosis related to radiation type were: single-energy protons, 54%; mixed-energy protons, 73%; X rays, 71%; and electrons, 57%. The incidence of endometriosis in nonirradiated control monkeys was 26%. Monkeys exposed to single-energy protons, mixed-energy protons, and X rays developed endometriosis at a significantly higher rate than control monkeys (chi 2, P less than 0.05). Severity of endometriosis was staged as massive, moderate, and minimal. The incidence of these stages were 65, 16, and 19%, respectively. Observations of clinical disease included weight loss in 43% of the monkeys, anorexia in 35%, space-occupying masses detected by abdominal palpation in 55%, abnormal ovarian/uterine anatomy on rectal examination in 89%, and radiographic evidence of abdominal masses in 38%. Pathological lesions were endometrial cyst formation in 69% of the monkeys, adhesions of the colon in 66%, urinary bladder in 50%, ovaries in 86%, and ureters in 44%, focal nodules of endometrial tissue throughout the omentum in 59%, and metastasis in 9%. Clinical management of endometriosis consisted of debulking surgery and bilateral salpingo-oophorectomy combined in some cases with total abdominal hysterectomy. Postoperative survival rates at 1 and 5 years for monkeys recovering from surgery were 48 and 36%, respectively.

  3. Stimulation of respiration in rat thymocytes induced by ionizing radiation.

    PubMed

    Gudz, T I; Pandelova, I G; Novgorodov, S A

    1994-04-01

    The effect of X irradiation on the respiration of rat thymocytes was studied. An increase in the rate of O2 uptake was observed 1 h after cells were irradiated with doses of 6-10 Gy. The radiation-induced increase in respiration could be blocked by oligomycin, an inhibitor of mitochondrial ATP synthase, suggesting control by increased cytoplasmic ATP turnover. The stimulation of respiration was not associated with changes in the activity of mitochondrial electron transfer enzymes or permeability of the inner membrane. Several inhibitors of processes which used ATP were screened for their effects on the basal respiration rate and on the radiation response. In irradiated thymocytes, an enhancement of inhibition of respiration by ouabain, La3+ and cycloheximide was observed. These results indicate that the radiation-induced stimulation of respiration is due to changes in ion homeostasis and protein synthesis. The effect of X irradiation was shown to be independent of the redox status of nonprotein thiols and was not associated with detectable changes in some products of lipid peroxidation. The radiation-induced decrease in activity of superoxide dismutase suggests free radical involvement in deleterious effects of radiation. PMID:8146290

  4. Radiation-induced conductivity control in polyaniline blends/composites

    NASA Astrophysics Data System (ADS)

    Güven, Olgun

    2007-08-01

    Polyaniline (PANI) blends with chlorine-containing polymers and copolymers and composites with HCl-releasing compounds were prepared to investigate their radiation response in terms of induced conductivities. Blends of non-conductive PANI with poly(vinyl chloride) (PVC), poly(vinylidene chloride- co-vinyl acetate), [P(VDC- co-VAc)], poly(vinylidene chloride- co-vinyl chloride), [P(VDC- co-VC)] were prepared in the form of as-cast films. A number of blends which are different in composition were exposed to gamma radiation and accelerated electrons to various doses, and the effects of irradiation type and composition of polymers on the conductivity of films were investigated by using conductivity measurements and UV-vis and FT-IR spectroscopy. The results clearly showed that ionizing radiation is an effective tool to induce and control conductivity in the blends of PANI-base with chlorine-carrying polymers as well as its composites prepared from HCl-releasing compounds such as chloral hydrate. The main mechanism behind this radiation-induced conductivity is in situ doping of PANI-base with HCl released from partner polymers and low molecular weight compounds by the effect of radiation.

  5. Clarithromycin Attenuates Radiation-Induced Lung Injury in Mice

    PubMed Central

    Lee, Seung Jun; Yi, Chin-ok; Heo, Rok Won; Song, Dae Hyun; Cho, Yu Ji; Jeong, Yi Yeong; Kang, Ki Mun; Roh, Gu Seob; Lee, Jong Deog

    2015-01-01

    Radiation-induced lung injury (RILI) is a common and unavoidable complication of thoracic radiotherapy. The current study was conducted to evaluate the ability of clarithromycin (CLA) to prevent radiation-induced pneumonitis, oxidative stress, and lung fibrosis in an animal model. C57BL/6J mice were assigned to control, irradiation only, irradiation plus CLA, and CLA only groups. Test mice received single thoracic exposures to radiation and/or oral CLA (100 mg/kg/day). Histopathologic findings and markers of inflammation, fibrosis, and oxidative stress were compared by group. On a microscopic level, CLA inhibited macrophage influx, alveolar fibrosis, parenchymal collapse, consolidation, and epithelial cell changes. The concentration of collagen in lung tissue was lower in irradiation plus CLA mice. Radiation-induced expression of tumor necrosis factor (TNF)-?, TNF receptor 1, acetylated nuclear factor kappa B, cyclooxygenase 2, vascular cell adhesion molecule 1, and matrix metallopeptidase 9 were also attenuated by CLA. Expression levels of nuclear factor erythroid 2-related factor 2 and heme oxygenase 1, transforming growth factor-?1, connective tissue growth factor, and type I collagen in radiation-treated lungs were also attenuated by CLA. These findings indicate that CLA ameliorates the deleterious effects of thoracic irradiation in mice by reducing pulmonary inflammation, oxidative damage, and fibrosis. PMID:26114656

  6. Introduction Mammals suffering from radiation-induced anemia or

    E-print Network

    Zandstra, Peter W.

    that distinguish the stem cell niche of the BM versus skeletal muscle microenvironments. Key words: Hematopoietic to endogenous muscle- derived satellite-stem-cells, this repair process was affected by a small numberIntroduction Mammals suffering from radiation-induced anemia or neutropenia can be rescued

  7. Mechanisms of radiation-induced degradation of reactor vessel materials

    Microsoft Academic Search

    L. K. Mansur; K. Farrell

    1997-01-01

    Fast neutrons are usually considered the source of various radiation effects caused by atom displacements, such as embrittlement, swelling, and creep. However, other reactions may contribute to atom displacements under certain conditions. These additional sources of displacements include those caused by thermal neutron capture recoils, ?-induced energetic electrons, and energetic particles emerging from transmutation reactions. In reactor vessels, for example,

  8. Simulation of ion induced radiation damage in cells

    Microsoft Academic Search

    W. Friedland; P. Jacob; H. G. Paretzke; A. Ottolenghi; F. Ballarini; M. Dingfelder

    2006-01-01

    The biophysical simulation code PARTRAC has been used in several studies of DNA damage induced by various radiation qualities including photons electrons protons alphas and ions heavier than alpha particles Ion-electron interaction cross sections are taken from isotachic protons scaled by Z eff 2 with the effective charge calculated according to the Barkas formula Recently ion type dependent angular distributions

  9. Heterogeneous shock-induced thermal radiation in minerals

    Microsoft Academic Search

    Ken-Ichi Kondo; Thomas J. Ahrens

    1983-01-01

    A 500 channel optical imaging intensifying and spectral digital recording system is used to record the shock-induced radiation emitted from 406 to 821 nm from transparent minerals during the time interval that a shock wave propagates through the sample. Initial results obtained for single crystals of gypsum, calcite and halite in the 30 to 40 GPa (300 to 400 kbar)

  10. SENSITIVITY TO RADIATION-INDUCED CANCER IN HEMOCHROMATOSIS

    EPA Science Inventory

    Determination of dose-response relationships for radiation-induced cancer in segments of the population with high susceptibility is critical for understanding the risks of low dose and low dose rates to humans. Clean-up levels for radionuclides will depend upon the fraction of t...

  11. Radiation-induced decomposition of explosives under extreme conditions

    SciTech Connect

    Giefers, Hubertus; Pravica, Michael; Yang, Wenge; Liermann, Peter (UNLV); (CIW)

    2008-11-03

    We present high-pressure and high temperature studies of the synchrotron radiation-induced decomposition of powder secondary high explosives pentaerythritol tetranitrate (PETN) and 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) using white beam synchrotron radiation at the 16 BM-B and 16 BM-D sectors of the HP-CAT beamline at the Advanced Photon Source. The radiation-induced decomposition rate TATB showed dramatic slowing with pressure up to 26.6 GPa (the highest pressure studied), implying a positive activation volume of the activated complex. The decomposition rate of PETN varied little with pressure up to 15.7 GPa (the highest pressure studied). Diffraction line intensities were measured as a function of time using energy-dispersive methods. By measuring the decomposition rate as a function of pressure and temperature, kinetic and other constants associated with the decomposition reactions were extracted.

  12. Radiation-induced basal cell carcinoma

    PubMed Central

    Zargari, Omid

    2015-01-01

    Background: The treatment of tinea capitis using radiotherapy was introduced at the beginning of the twentieth century. A variety of cancers including basal cell carcinoma (BCC) are seen years after this treatment. Objective: We sought to determine the clinical characteristics of BCCs among irradiated patients. Methods: The clinical records of all patients with BCC in a clinic in north of Iran were reviewed. Results: Of the 58 cases of BCC, 29 had positive history for radiotherapy in their childhood. Multiple BCCs were seen in 79.3% and 10.3% of patients with history and without history of radiotherapy, respectively. Conclusions: X-ray radiation is still a major etiologic factor in developing BCC in northern Iran. Patients with positive history for radiotherapy have higher rate of recurrence.

  13. Radiation-Induced Bystander Response: Mechanism and Clinical Implications.

    PubMed

    Suzuki, Keiji; Yamashita, Shunichi

    2014-01-01

    Significance: Absorption of energy from ionizing radiation (IR) to the genetic material in the cell gives rise to damage to DNA in a dose-dependent manner. There are two types of DNA damage; by a high dose (causing acute or deterministic effects) and by a low dose (related to chronic or stochastic effects), both of which induce different health effects. Among radiation effects, acute cutaneous radiation syndrome results from cell killing as a consequence of high-dose exposure. Recent advances: Recent advances in radiation biology and oncology have demonstrated that bystander effects, which are emerged in cells that have never been exposed, but neighboring irradiated cells, are also involved in radiation effects. Bystander effects are now recognized as an indispensable component of tissue response related to deleterious effects of IR. Critical issues: Evidence has indicated that nonapoptotic premature senescence is commonly observed in various tissues and organs. Senesced cells were found to secrete various proteins, including cytokines, chemokines, and growth factors, most of which are equivalent to those identified as bystander factors. Secreted factors could trigger cell proliferation, angiogenesis, cell migration, inflammatory response, etc., which provide a tissue microenvironment assisting tissue repair and remodeling. Future directions: Understandings of the mechanisms and physiological relevance of radiation-induced bystander effects are quite essential for the beneficial control of wound healing and care. Further studies should extend our knowledge of the mechanisms of bystander effects and mode of cell death in response to IR. PMID:24761341

  14. Radiation-induced dural fibrosarcoma with unusually short latent period

    SciTech Connect

    Ghatak, N.R.; Aydin, F.; Leshner, R.T. (Medical College of Virginia, Richmond (United States) Tulane Univ., New Orleans, LA (United States))

    1993-05-01

    Although rare, the occurrence of radiation-induced intracranial neoplasms of various types is well known. Among these tumors, fibrosarcomas, especially in the region of seila turcica, seem to be the most common type. These tumors characteristically occur after a long latent period, usually several years, following radiation therapy. The authors now report a case of apparently radiation-induced fibrosarcoma with some unusual features in a 10-year-old boy who was treated with radiation for medulloblastoma. He received a total dose of 53.2 Gy radiation delivered at 1.8 per fraction with 6 MV acceleration using the standard craniospinal technique. An MRI at 15 months after the completion of radiotherapy showed a mass over the cerebral convexity, which increased two-fold in size within a period of 4 months. A well circumscribed tumor was removed from the fronto-parietal convexity. The tumor measured 5x4.5x1.5 cm and was attached to the dura with invasion of the overlying bone. Histologically, it displayed the characteristic features of a low-grade fibrosarcoma. The patient remains free of tumor 18 months after the surgery. This case emphasizes the potential risk for the development of a second neoplasm following therapeutic radiation and also documents, to the authors' knowledge, the shortest latent period reported so far between administration of radiotherapy and development of an intracranial tumor.

  15. Radiation-Induced Bystander Response: Mechanism and Clinical Implications

    PubMed Central

    Suzuki, Keiji; Yamashita, Shunichi

    2014-01-01

    Significance: Absorption of energy from ionizing radiation (IR) to the genetic material in the cell gives rise to damage to DNA in a dose-dependent manner. There are two types of DNA damage; by a high dose (causing acute or deterministic effects) and by a low dose (related to chronic or stochastic effects), both of which induce different health effects. Among radiation effects, acute cutaneous radiation syndrome results from cell killing as a consequence of high-dose exposure. Recent advances: Recent advances in radiation biology and oncology have demonstrated that bystander effects, which are emerged in cells that have never been exposed, but neighboring irradiated cells, are also involved in radiation effects. Bystander effects are now recognized as an indispensable component of tissue response related to deleterious effects of IR. Critical issues: Evidence has indicated that nonapoptotic premature senescence is commonly observed in various tissues and organs. Senesced cells were found to secrete various proteins, including cytokines, chemokines, and growth factors, most of which are equivalent to those identified as bystander factors. Secreted factors could trigger cell proliferation, angiogenesis, cell migration, inflammatory response, etc., which provide a tissue microenvironment assisting tissue repair and remodeling. Future directions: Understandings of the mechanisms and physiological relevance of radiation-induced bystander effects are quite essential for the beneficial control of wound healing and care. Further studies should extend our knowledge of the mechanisms of bystander effects and mode of cell death in response to IR. PMID:24761341

  16. Radiation-induced cardiomyopathy as a function of radiation beam gating to the cardiac cycle

    Microsoft Academic Search

    David J Gladstone; Michael F Flanagan; Jean B Southworth; Vaughn Hadley; Melissa Wei Thibualt; Eugen B Hug; P Jack Hoopes

    2004-01-01

    Portions of the heart are often unavoidably included in the primary treatment volume during thoracic radiotherapy, and radiation-induced heart disease has been observed as a treatment-related complication. Such complications have been observed in humans following radiation therapy for Hodgkin's disease and treatment of the left breast for carcinoma. Recent attempts have been made to prevent re-stenosis following angioplasty procedures using

  17. Initial studies on the crystallinity of the mineral fraction and ash content of isolated human and bovine osteons differing in their degree of calcification

    Microsoft Academic Search

    A. Ascenzi; E. Bonucci; K. Ostrowski; A. Sliwowski; A. Dziedzic-Goc?awska; W. Stachowicz; J. Michalik

    1977-01-01

    Summary Several groups containing 10–15 isolated osteons differing in their degree of maturity were analysed. Samples were isolated from undecalcified human and bovine bone sections. The crystallinity coefficient, defined as the ratio of the number of radiation-induced paramagnetic defects in the crystalline lattice of hydroxyapatite to the total ash content, was calculated. The results were compared with measurements performed on

  18. Radiation-induced transient attenuation of PCS fiber

    SciTech Connect

    Lyons, P.B.; Looney, L.D.; Ogle, J.W.

    1983-01-01

    Some applications of optical fibers require their exposure to intense radiation fields. This exposure can potentially degrade performance of a fiber data link. Research at Los Alamos National Laboratory has recently concentrated on development of an understanding of such radiation effects at short times, less than 100 ns. In previous papers we have identified a particular type of fiber, ITT plastic-clad-silica (PCS) with Suprasil core as optimum for short time radiation-induced attenuation, but that work used very large doses of ionizing radiation, close to 1 Mrad. For these high dose exposures, moderate success in understanding the transient nature of the attenuation was realized with a geminate recombination model. In this paper, we report further studies with ITT PCS fiber over a range of doses and wavelengths. Data on other PCS fibers is included that provide performance comparable to the ITT product. Comparison to several fluorsilicate fibers is also included.

  19. Radiation-induced DNA damage and chromatin structure

    NASA Technical Reports Server (NTRS)

    Rydberg, B.; Chatterjee, A. (Principal Investigator)

    2001-01-01

    DNA lesions induced by ionizing radiation in cells are clustered and not randomly distributed. For low linear energy transfer (LET) radiation this clustering occurs mainly on the small scales of DNA molecules and nucleosomes. For example, experimental evidence suggests that both strands of DNA on the nucleosomal surface can be damaged in single events and that this damage occurs with a 10-bp modulation because of protection by histones. For high LET radiation, clustering also occurs on a larger scale and depends on chromatin organization. A particularly significant clustering occurs when an ionizing particle traverses the 30 nm chromatin fiber with generation of heavily damaged DNA regions with an average size of about 2 kbp. On an even larger scale, high LET radiation can produce several DNA double-strand breaks in closer proximity than expected from randomness. It is suggested that this increases the probability of misrejoining of DNA ends and generation of lethal chromosome aberrations.

  20. Factors that modify risks of radiation-induced cancer

    SciTech Connect

    Fabrikant, J.I.

    1988-11-01

    The collective influence of biologic and physical factors that modify risks of radiation-induced cancer introduces uncertainties sufficient to deny precision of estimates of human cancer risk that can be calculated for low-dose radiation in exposed populations. The important biologic characteristics include the tissue sites and cell types, baseline cancer incidence, minimum latent period, time-to-tumor recognition, and the influence of individual host (age and sex) and competing etiologic influences. Physical factors include radiation dose, dose rate, and radiation quality. Statistical factors include time-response projection models, risk coefficients, and dose-response relationships. Other modifying factors include other carcinogens, and other biological sources (hormonal status, immune status, hereditary factors).

  1. Radiation-induced swelling of stainless steel.

    PubMed

    Shewmon, P G

    1971-09-10

    Significant swelling (1 to 10 percent due to small voids have been found in stainless steel when it is exposed to fast neutron doses less than expected in commercial fast breeder reactors. The main features of this new effect are: (i) the voids are formed by the precipitation of a small fraction of the radiation-produced vacancies; (ii) the voids form primarily in the temperature range 400 degrees to 600 degrees C (750 degrees to 1100 degrees F); and (iii) the volume increases with dose (fluence) at a rate between linear and parabolic. The limited temperature range of void formation can be explained, but the effects of fluence, microstructure, and composition are determined by a competition between several kinetic processes that are not well understood. This swelling does not affect the feasibility or safety of the breeder reactor,but will have a significant impact on the core design and economics of the breeder.Preliminary results indicate that one cannot eliminate the effect,but cold-working,heat treatment, or small changes in composition can reduce the swelling by a factor of 2 or more. Testing is hampered by the fact that several years in EBR-II are required to accumulate the fluence expected in demonstration plants. Heavyion accelerators,which allow damage rates corresponding to much higher fluxes than those found in EBR-II,hold great promise for short-term tests that will indicate the relative effect of the important variables. PMID:17796573

  2. Mechanisms of radiation-induced gene responses

    SciTech Connect

    Woloschak, G.E.; Paunesku, T.

    1996-10-01

    In the process of identifying genes differentially expressed in cells exposed ultraviolet radiation, we have identified a transcript having a 26-bp region that is highly conserved in a variety of species including Bacillus circulans, yeast, pumpkin, Drosophila, mouse, and man. When the 5` region (flanking region or UTR) of a gene, the sequence is predominantly in +/+ orientation with respect to the coding DNA strand; while in the coding region and the 3` region (UTR), the sequence is most frequently in the +/-orientation with respect to the coding DNA strand. In two genes, the element is split into two parts; however, in most cases, it is found only once but with a minimum of 11 consecutive nucleotides precisely depicting the original sequence. The element is found in a large number of different genes with diverse functions (from human ras p21 to B. circulans chitonase). Gel shift assays demonstrated the presence of a protein in HeLa cell extracts that binds to the sense and antisense single-stranded consensus oligomers, as well as to the double- stranded oligonucleotide. When double-stranded oligomer was used, the size shift demonstrated as additional protein-oligomer complex larger than the one bound to either sense or antisense single-stranded consensus oligomers alone. It is speculated either that this element binds to protein(s) important in maintaining DNA is a single-stranded orientation for transcription or, alternatively that this element is important in the transcription-coupled DNA repair process.

  3. Single-crystalline Bi2Sr2CaCu2O8+x detectors for direct detection of microwave radiation

    NASA Astrophysics Data System (ADS)

    Li, M.; Winkler, D.; Yurgens, A.

    2015-04-01

    We test radiation detectors made from single-crystalline Bi2Sr2CaCu2O8+x flakes put on oxidized Si substrates. The 100-nm-thick flakes are lithographically patterned into 4 ×12 ?m2 large rectangles embedded in thin-film log-spiral antennas. The SiO2 layer weakens the thermal link between the flakes and the bath. Two modes of radiation detection have been observed. For a bolometric type of sensors a responsivity of ˜300 V/W and a noise equivalent power of 30 nW/ ?{Hz } has been deduced at 70 K. Much more sensitive is the non-bolometric device showing characteristics similar to a Golay-type detector while being at least a thousand times faster. Making smaller (sub-?m) structures is expected to significantly improve the performance of these devices and makes them very competitive among other microwave and terahertz detectors.

  4. Induced movements of giant vesicles by millimeter wave radiation.

    PubMed

    Albini, Martina; Dinarelli, Simone; Pennella, Francesco; Romeo, Stefania; Zampetti, Emiliano; Girasole, Marco; Morbiducci, Umberto; Massa, Rita; Ramundo-Orlando, Alfonsina

    2014-07-01

    Our previous study of interaction between low intensity radiation at 53.37GHz and cell-size system - such as giant vesicles - indicated that a vectorial movement of vesicles was induced. This effect among others, i.e. elongation, induced diffusion of fluorescent dye di-8-ANEPPS, and increased attractions between vesicles was attributed to the action of the field on charged and dipolar residues located at the membrane-water interface. In an attempt to improve the understanding on how millimeter wave radiation (MMW) can induce this movement we report here a real time evaluation of changes induced on the movement of giant vesicles. Direct optical observations of vesicles subjected to irradiation enabled the monitoring in real time of the response of vesicles. Changes of the direction of vesicle movement are demonstrated, which occur only during irradiation with a "switch on" of the effect. This MMW-induced effect was observed at a larger extent on giant vesicles prepared with negatively charged phospholipids. The monitoring of induced-by-irradiation temperature variation and numerical dosimetry indicate that the observed effects in vesicle movement cannot be attributed to local heating. PMID:24704354

  5. [Update - health risks induced by ionizing radiation from diagnostic imaging].

    PubMed

    Knüsli, Claudio; Walter, Martin

    2013-12-01

    Ionizing radiation is the most thoroughly investigated exogenous noxa. Since the early 20th century it is well known that using ionizing radiation in diagnostic procedures causes cancer - physicians themselves frequently being struck by this disease in those early days of radiology. Radiation protection therefore plays an important role. Below doses of 100 Millisievert (mSv) however much research has to be accomplished yet because not only malignant tumors, but cardiovascular diseases, malformations and genetic sequelae attributable to low dose radiation have been described. Unborns, children and adolescents are highly vulnerable. Dose response correlations are subject to continuing discussions because data stem mostly from calculations studying Japanese atomic bomb survivors. Radiation exposure is not exactly known, and it is unknown, if observations of radiation induced diseases in this ethnicity can be generalized. Nowadays the main source of low dose ionizing radiation from medical diagnostics is due to computertomography (CT). Large recent clinical studies from the UK and Australia investigating cancer incidence after exposition to CT in childhood and adolescence confirm that low doses in the range of 5 mSv already significantly increase the risk of malignant diseases during follow up. Imaging techniques as ultrasound and magnetic resonance tomography therefore should be preferred whenever appropriate. PMID:24297861

  6. Radiation-Induced Notch Signaling in Breast Cancer Stem Cells

    SciTech Connect

    Lagadec, Chann [Department of Radiation Oncology, David Geffen School of Medicine at University of California, Los Angeles (UCLA), Los Angeles, California (United States); Vlashi, Erina [Department of Radiation Oncology, David Geffen School of Medicine at University of California, Los Angeles (UCLA), Los Angeles, California (United States); Jonsson Comprehensive Cancer Center at UCLA, Los Angeles, California (United States); Alhiyari, Yazeed; Phillips, Tiffany M.; Bochkur Dratver, Milana [Department of Radiation Oncology, David Geffen School of Medicine at University of California, Los Angeles (UCLA), Los Angeles, California (United States); Pajonk, Frank, E-mail: fpajonk@mednet.ucla.edu [Department of Radiation Oncology, David Geffen School of Medicine at University of California, Los Angeles (UCLA), Los Angeles, California (United States); Jonsson Comprehensive Cancer Center at UCLA, Los Angeles, California (United States)

    2013-11-01

    Purpose: To explore patterns of Notch receptor and ligand expression in response to radiation that could be crucial in defining optimal dosing schemes for ?-secretase inhibitors if combined with radiation. Methods and Materials: Using MCF-7 and T47D breast cancer cell lines, we used real-time reverse transcription–polymerase chain reaction to study the Notch pathway in response to radiation. Results: We show that Notch receptor and ligand expression during the first 48 hours after irradiation followed a complex radiation dose–dependent pattern and was most pronounced in mammospheres, enriched for breast cancer stem cells. Additionally, radiation activated the Notch pathway. Treatment with a ?-secretase inhibitor prevented radiation-induced Notch family gene expression and led to a significant reduction in the size of the breast cancer stem cell pool. Conclusions: Our results indicate that, if combined with radiation, ?-secretase inhibitors may prevent up-regulation of Notch receptor and ligand family members and thus reduce the number of surviving breast cancer stem cells.

  7. Radiation-induced alterations in cytokine production by skin cells.

    PubMed

    Müller, Kerstin; Meineke, Viktor

    2007-04-01

    Ionizing radiation exposure of skin results in a cutaneous radiation reaction comprising all pathophysiological reactions and clinical symptoms in irradiated skin. Biological responses of skin occur in a characteristic temporal pattern and mainly depend on radiation quality, dose rate, total dose, and cellular conditions. Immediately after irradiation, production of cytokines by skin cells is initiated and continues as a cascade during all stages of the cutaneous radiation syndrome leading to progressive late symptoms, the predominant of which is fibrosis. Cytokines are important signaling molecules mediating communicative interactions both locally between different cell types within dermal tissues and distantly between organs. Although during recent years much progress has been made in dissecting the complex cytokine network, the role of cytokines in the pathophysiology of the cutaneous radiation reaction is only beginning to be elucidated. Previous studies indicate that the major cytokines in the response of skin cells to ionizing radiation include IL (interleukin)-1, IL-6, tumor necrosis factor (TNF)-alpha, transforming growth factor (TGF)-beta, and the chemokines IL-8 and eotaxin. In this paper, existing data on the radiation-induced modulation of cytokine expression by skin cells are reviewed. PMID:17379094

  8. Radiation-induced optic neuropathy: A magnetic resonance imaging study

    SciTech Connect

    Guy, J.; Mancuso, A.; Beck, R.; Moster, M.L.; Sedwick, L.A.; Quisling, R.G.; Rhoton, A.L. Jr.; Protzko, E.E.; Schiffman, J. (Univ. of Florida, Gainesville (USA))

    1991-03-01

    Optic neuropathy induced by radiation is an infrequent cause of delayed visual loss that may at times be difficult to differentiate from compression of the visual pathways by recurrent neoplasm. The authors describe six patients with this disorder who experienced loss of vision 6 to 36 months after neurological surgery and radiation therapy. Of the six patients in the series, two had a pituitary adenoma and one each had a metastatic melanoma, multiple myeloma, craniopharyngioma, and lymphoepithelioma. Visual acuity in the affected eyes ranged from 20/25 to no light perception. Magnetic resonance (MR) imaging showed sellar and parasellar recurrence of both pituitary adenomas, but the intrinsic lesions of the optic nerves and optic chiasm induced by radiation were enhanced after gadolinium-diethylenetriaminepenta-acetic acid (DTPA) administration and were clearly distinguishable from the suprasellar compression of tumor. Repeated MR imaging showed spontaneous resolution of gadolinium-DTPA enhancement of the optic nerve in a patient who was initially suspected of harboring recurrence of a metastatic malignant melanoma as the cause of visual loss. The authors found the presumptive diagnosis of radiation-induced optic neuropathy facilitated by MR imaging with gadolinium-DTPA. This neuro-imaging procedure may help avert exploratory surgery in some patients with recurrent neoplasm in whom the etiology of visual loss is uncertain.

  9. Radiation-induced transmissable chromosomal instability in haemopoietic stem cells

    NASA Astrophysics Data System (ADS)

    Kadhim, M. A.; Wright, E. G.

    Heritable radiation-induced genetic alterations have long been assumed to be ``fixed'' within the first cell division. However, there is a growing body of evidence that a considerable fraction of cells surviving radiation exposure appear normal, but a variety of mutational changes arise in their progeny due to a transmissible genomic instability. In our investigations of G-banded metaphases, non-clonal cytogenetic aberrations, predominantly chromatid-type aberrations, have been observed in the clonal descendants of murine and human haemopoietic stem cells surviving low doses (~1 track per cell) of alpha-particle irradiations. The data are consistent with a transmissible genetic instability induced in a stem cell resulting in a diversity of chromosomal aberrations in its clonal progeny many cell divisions later. Recent studies have demonstrated that the instability phenotype persists in vivo and that the expression of chromosomal instability has a strong dependence on the genetic characteristics of the irradiated cell. At the time when cytogenetic aberrations are detected, an increased incidence of hprt mutations and apoptotic cells have been observed in the clonal descendants of alpha-irradiated murine haemopoietic stem cells. Thus, delayed chromosomal abnormalities, delayed cell death by apoptosis and late-arising specific gene mutations may reflect diverse consequences of radiation-induced genomic instability. The relationship, if any, between these effects is not established. Current studies suggest that expression of these delayed heritable effects is determined by the type of radiation exposure, type of cell and a variety of genetic factors.

  10. Radiation-induced skin carcinomas of the head and neck

    SciTech Connect

    Ron, E.; Modan, B.; Preston, D.; Alfandary, E.; Stovall, M.; Boice, J.D. Jr. (National Cancer Institute, Bethesda, MD (USA))

    1991-03-01

    Radiation exposures to the scalp during childhood for tinea capitis were associated with a fourfold increase in skin cancer, primarily basal cell carcinomas, and a threefold increase in benign skin tumors. Malignant melanoma, however, was not significantly elevated. Overall, 80 neoplasms were identified from an extensive search of the pathology logs of all major hospitals in Israel and computer linkage with the national cancer registry. Radiation dose to the scalp was computed for over 10,000 persons irradiated for ringworm (mean 7 Gy), and incidence rates were contrasted with those observed in 16,000 matched comparison subjects. The relative risk of radiogenic skin cancer did not differ significantly between men or women or by time since exposure; however, risk was greatest following exposures in early childhood. After adjusting for sex, ethnic origin, and attained age, the estimated excess relative risk was 0.7 per Gy and the average excess risk over the current follow-up was 0.31/10(4) PY-Gy. The risk per Gy of radiation-induced skin cancer was intermediate between the high risk found among whites and no risk found among blacks in a similar study conducted in New York City. This finding suggests the role that subsequent exposure to uv radiation likely plays in the expression of a potential radiation-induced skin malignancy.

  11. Deoxycholate induced tetramer of ?A-crystallin and sites of phosphorylation: Fluorescence correlation spectroscopy and femtosecond solvation dynamics

    NASA Astrophysics Data System (ADS)

    Chowdhury, Aritra; Mojumdar, Supratik Sen; Choudhury, Aparajita; Banerjee, Rajat; Das, Kali Pada; Sasmal, Dibyendu Kumar; Bhattacharyya, Kankan

    2012-04-01

    Structure and dynamics of acrylodan labeled ?A-crystallin tetramer formed in the presence of a bile salt (sodium deoxycholate, NaDC) has been studied using fluorescence correlation spectroscopy (FCS) and femtosecond up-conversion techniques. Using FCS it is shown that, the diffusion constant (Dt) of the ?A-crystallin oligomer (mass ˜800 kDa) increases from ˜35 ?m2 s-1 to ˜68 ?m2 s-1. This corresponds to a decrease in hydrodynamic radius (rh) from ˜6.9 nm to ˜3.3 nm. This corresponds to about 10-fold decrease in molecular mass to ˜80 kDa and suggests formation of a tetramer (since mass of ?A-crystallin monomer is ˜20 kDa). The steady state emission maximum and average solvation time () of acrylodan labeled at cysteine 131 position of ?A-crystallin is markedly affected on addition of NaDC, while the tryptophan (trp-9) becomes more exposed. This suggests that NaDC binds near the cys-131 and makes the terminal region of ?A-crystallin exposed. This may explain the enhanced auto-phosphorylation activity of ?A-crystallin near the terminus of the 173 amino acid protein (e.g., at the threonine 13, serine 45, or serine 169 and 172) and suggests that phosphorylation at ser-122 (close to cys-131) is relatively less important.

  12. Radiation-induced bystander effects: what are they, and how relevant are they to human radiation exposures?

    PubMed

    Blyth, Benjamin J; Sykes, Pamela J

    2011-08-01

    The term radiation-induced bystander effect is used to describe radiation-induced biological changes that manifest in unirradiated cells remaining within an irradiated cell population. Despite their failure to fit into the framework of classical radiobiology, radiation-induced bystander effects have entered the mainstream and have become established in the radiobiology vocabulary as a bona fide radiation response. However, there is still no consensus on a precise definition of radiation-induced bystander effects, which currently encompasses a number of distinct signal-mediated effects. These effects are classified here into three classes: bystander effects, abscopal effects and cohort effects. In this review, the data have been evaluated to define, where possible, various features specific to radiation-induced bystander effects, including their timing, range, potency and dependence on dose, dose rate, radiation quality and cell type. The weight of evidence supporting these defining features is discussed in the context of bystander experimental systems that closely replicate realistic human exposure scenarios. Whether the manifestation of bystander effects in vivo is intrinsically limited to particular radiation exposure scenarios is considered. The conditions under which radiation-induced bystander effects are induced in vivo will ultimately determine their impact on radiation-induced carcinogenic risk. PMID:21631286

  13. The radiation-induced changes in rectal mucosa: Hyperfractionated vs. hypofractionated preoperative radiation for rectal cancer

    SciTech Connect

    Starzewski, Jacek J. [Department of General and Colorectal Surgery, Medical University of Silesia, Sosnowiec (Poland); Pajak, Jacek T. [Department of Pathology, Medical University of Silesia, Katowice (Poland); Pawelczyk, Iwona [Department of General and Colorectal Surgery, Medical University of Silesia, Sosnowiec (Poland); Lange, Dariusz [Department of Tumor Pathology, Comprehensive Cancer Center Division, Gliwice (Poland); Golka, Dariusz [Department of Pathology, Medical University of Silesia, Katowice (Poland)]. E-mail: dargolka@wp.pl; Brzeziska, Monika [Department of General and Colorectal Surgery, Medical University of Silesia, Sosnowiec (Poland); Lorenc, Zbigniew [Department of General and Colorectal Surgery, Medical University of Silesia, Sosnowiec (Poland)

    2006-03-01

    Purpose: The purpose of the study was the qualitative and quantitative evaluation of acute radiation-induced rectal changes in patients who underwent preoperative radiotherapy according to two different irradiation protocols. Patients and Methods: Sixty-eight patients with rectal adenocarcinoma underwent preoperative radiotherapy; 44 and 24 patients underwent hyperfractionated and hypofractionated protocol, respectively. Fifteen patients treated with surgery alone served as a control group. Five basic histopathologic features (meganucleosis, inflammatory infiltrations, eosinophils, mucus secretion, and erosions) and two additional features (mitotic figures and architectural glandular abnormalities) of radiation-induced changes were qualified and quantified. Results: Acute radiation-induced reactions were found in 66 patients. The most common were eosinophilic and plasma-cell inflammatory infiltrations (65 patients), erosions, and decreased mucus secretion (54 patients). Meganucleosis and mitotic figures were more common in patients who underwent hyperfractionated radiotherapy. The least common were the glandular architectural distortions, especially in patients treated with hypofractionated radiotherapy. Statistically significant differences in morphologic parameters studied between groups treated with different irradiation protocols were found. Conclusion: The system of assessment is a valuable tool in the evaluation of radiation-induced changes in the rectal mucosa. A greater intensity of regenerative changes was found in patients treated with hyperfractionated radiotherapy.

  14. Radiation-induced cardiomyopathy as a function of radiation beam gating to the cardiac cycle

    NASA Astrophysics Data System (ADS)

    Gladstone, David J.; Flanagan, Michael F.; Southworth, Jean B.; Hadley, Vaughn; Thibualt, Melissa Wei; Hug, Eugen B.; Hoopes, P. Jack

    2004-04-01

    Portions of the heart are often unavoidably included in the primary treatment volume during thoracic radiotherapy, and radiation-induced heart disease has been observed as a treatment-related complication. Such complications have been observed in humans following radiation therapy for Hodgkin's disease and treatment of the left breast for carcinoma. Recent attempts have been made to prevent re-stenosis following angioplasty procedures using external beam irradiation. These attempts were not successful, however, due to the large volume of heart included in the treatment field and subsequent cardiac morbidity. We suggest a mechanism for sparing the heart from radiation damage by synchronizing the radiation beam with the cardiac cycle and delivering radiation only when the heart is in a relatively hypoxic state. We present data from a rat model testing this hypothesis and show that radiation damage to the heart can be altered by synchronizing the radiation beam with the cardiac cycle. This technique may be useful in reducing radiation damage to the heart secondary to treatment for diseases such as Hodgkin's disease and breast cancer.

  15. Radiation-quality-dependent bystander effects induced by the microbeams with different radiation sources

    PubMed Central

    Suzuki, M.; Autsavapromporn, N.; Usami, N.; Funayama, T.; Plante, I.; Yokota, Y.; Mutou; Suzuki, M.; Ikeda, H.; Hattori, Y.; Kobayashi, K.; Kobayashi, Y.; Murakami, T.

    2014-01-01

    A central paradigm in radiation biology has been that only cells ‘hit’ by a track of radiation would be affected to induce radiobiological consequences, and cells ‘not hit’ should not be. This is the basis of the current system for risk estimation of radiobiological effects. However, it has recently been challenged by so-called non-targeted effects, such as bystander effect, and such radiation-induced cellular responses may have important implications for risk evaluation of low-dose-rate radiations as well as in tumor radiotherapy. Our group has been studying radiation-quality bystander cellular effects using the microbeams with different radiation sources. It is essentially important for evaluating risk such a low-dose-rate exposure as the accident of Fukushima Daiichi Nuclear Power Plants to examine bystander effects induced by low-LET electromagnetic radiations, such as X or gamma rays. We have been studying the cellular responses in normal human fibroblasts by targeted cell nucleus irradiations with monochromatic X-ray microbeams (5.35 keV) produced by Photon Factory in High Energy Accelerator Research Organization. The results indicated that the bystander effect in cell- killing effect was observed in the targeted cell nucleus irradiation, not in the random irradiation containing both cell nucleus and cytoplasm by Poisson distribution. The results suggest that energy deposition in cytoplasm is an important role of inducing bystander effects in case of low-LET radiations. We have also been investigating high-LET-radiation induced bystander effects using the heavy-ion microbeams at Takasaki Ion Accelerators for Advanced Radiation Application in Japan Atomic Energy Agency. Only 0.04% of the total numbers of normal human fibroblasts were irradiated with C-ion (220 MeV), Ne-ion (260 MeV) and Ar-ion (460 MeV) microbeams collimated at 20 ?m in diameter. Cell-killing effect and gene mutation at HPRT locus in the cells irradiated with C ions were higher beyond our expectations and returned the estimated values that only 0.04% of the total cells were irradiated when using the specific inhibitor of gap junctions. On the other hand, no induced biological effects were observed in Ne and Ar ions whether the inhibitor was applied or not. The result suggested that the C-ion microbeam was capable of inducing bystander cellular effects via gap junction-mediated cell-cell communication. There is clear evidence that bystander cellular effects are dependent on radiation quality. It is also important for highly developed heavy-ion radiotherapy to identify bystander effects induced by spatially low-fluence irradiations with heavy-ion beams. We have been investigating the biological effects using human tumor cell lines. The results clearly showed that bystander effects were observed in the carbon-ion irradiation but not in other ions as well as the effects in normal fibroblasts. Furthermore, the bystander cell-killing effect in tumor cell lines was strongly induced in the cells harboring wild-type P53 not in mutated-type P53 cells. The results provide the important implication for a tailor-made therapy using carbon ions.

  16. Cosmic Microwave Background Radiation Anisotropy Induced by Cosmic Strings

    E-print Network

    B. Allen; R. R. Caldwell; E. P. S. Shellard; A. Stebbins; S. Veeraraghavan

    1994-07-14

    We report on a current investigation of the anisotropy pattern induced by cosmic strings on the cosmic microwave background radiation (MBR). We have numerically evolved a network of cosmic strings from a redshift of $Z = 100$ to the present and calculated the anisotropies which they induce. Based on a limited number of realizations, we have compared the results of our simulations with the observations of the COBE-DMR experiment. We have obtained a preliminary estimate of the string mass-per-unit-length $\\mu$ in the cosmic string scenario.

  17. Intense UV excimer radiation from laser-induced plasmas

    NASA Astrophysics Data System (ADS)

    Onkels, E. D.; Seelig, W.

    1997-08-01

    Investigations of laser-induced plasmas have been undertaken with the aim of generating intense excimer fluorescence radiation. Experiments carried out on a KrF* excimer plasma system had very promising results. Through an unconventional intra-cavity arrangement of the pump laser it is possible to obtain homogeneity and stability together with an induced plasma with an overall length of about 10 cm. The attained optical gain of the plasma on the KrF* band at 248 nm reaches 25 m-1, which amounts to approximately twice the gain of conventional gas discharges. This paper gives a brief description of the theoretical modeling and applied experimental techniques.

  18. Oxidative Stress Mediates Radiation Lung Injury by Inducing Apoptosis

    SciTech Connect

    Zhang Yu; Zhang Xiuwu; Rabbani, Zahid N. [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Jackson, Isabel L. [Department of Pathology, Duke University Medical Center, Durham, NC (United States); Vujaskovic, Zeljko, E-mail: vujas@radonc.duke.edu [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Department of Pathology, Duke University Medical Center, Durham, NC (United States)

    2012-06-01

    Purpose: Apoptosis in irradiated normal lung tissue has been observed several weeks after radiation. However, the signaling pathway propagating cell death after radiation remains unknown. Methods and Materials: C57BL/6J mice were irradiated with 15 Gy to the whole thorax. Pro-apoptotic signaling was evaluated 6 weeks after radiation with or without administration of AEOL10150, a potent catalytic scavenger of reactive oxygen and nitrogen species. Results: Apoptosis was observed primarily in type I and type II pneumocytes and endothelium. Apoptosis correlated with increased PTEN expression, inhibition of downstream PI3K/AKT signaling, and increased p53 and Bax protein levels. Transforming growth factor-{beta}1, Nox4, and oxidative stress were also increased 6 weeks after radiation. Therapeutic administration of AEOL10150 suppressed pro-apoptotic signaling and dramatically reduced the number of apoptotic cells. Conclusion: Increased PTEN signaling after radiation results in apoptosis of lung parenchymal cells. We hypothesize that upregulation of PTEN is influenced by Nox4-derived oxidative stress. To our knowledge, this is the first study to highlight the role of PTEN in radiation-induced pulmonary toxicity.

  19. Using Imaging Methods to Interrogate Radiation-Induced Cell Signaling

    SciTech Connect

    Shankaran, Harish; Weber, Thomas J.; Freiin von Neubeck, Claere H.; Sowa, Marianne B.

    2012-04-01

    There is increasing emphasis on the use of systems biology approaches to define radiation induced responses in cells and tissues. Such approaches frequently rely on global screening using various high throughput 'omics' platforms. Although these methods are ideal for obtaining an unbiased overview of cellular responses, they often cannot reflect the inherent heterogeneity of the system or provide detailed spatial information. Additionally, performing such studies with multiple sampling time points can be prohibitively expensive. Imaging provides a complementary method with high spatial and temporal resolution capable of following the dynamics of signaling processes. In this review, we utilize specific examples to illustrate how imaging approaches have furthered our understanding of radiation induced cellular signaling. Particular emphasis is placed on protein co-localization, and oscillatory and transient signaling dynamics.

  20. Non-radiation induced signals in TL dosimetry.

    PubMed

    German, U; Weinstein, M

    2002-01-01

    One source of background signals, which are non-radiation related, is the reader system and it includes dark current, external contaminants and electronic spikes. These factors can induce signals equivalent to several hundredths of mSv. Mostly, the effects are minimised by proper design of the TLD reader, but some effects are dependent on proper operation of the system. The other main group of background signals originates in the TL crystal and is due to tribothermoluminescence, dirt, chemical reactions and stimulation by visible or UV light. These factors can have a significant contribution, equivalent to over several mSv, depending on whether the crystal is bare or protected by PTFE. Working in clean environments, monitoring continuously the glow curves and performing glow curve deconvolution are suggested to minimise non-radiation induced spurious signals. PMID:12382710

  1. Caffeine Markedly Enhanced Radiation-Induced Bystander Effects

    NASA Astrophysics Data System (ADS)

    Jiang, Erkang; Wu, Lijun

    2009-04-01

    In this paper it is shown that incubation with 2 mM caffeine enhanced significantly the MN (micronucleus) formation in both the 1 cGy ?-particle irradiated and non-irradiated bystander regions. Moreover, caffeine treatment made the non-irradiated bystander cells more sensitive to damage signals. Treated by c-PTIO(2-(4-carboxy-phenyl)-4,4,5,5-tetramethyl-imidazoline-1-oxyl-3-oxide), a nitric oxide (NO) scavenger, the MN frequencies were effectively inhibited, showing that nitric oxide might be very important in mediating the enhanced damage. These results indicated that caffeine enhanced the low dose ?-particle radiation-induced damage in irradiated and non-irradiated bystander regions, and therefore it is important to investigate the relationship between the radiosensitizer and radiation-induced bystander effects (RIBE).

  2. Aspergillus parasellar abscess mimicking radiation-induced neuropathy

    Microsoft Academic Search

    Toshiki Endo; Yoshihiro Numagami; Hidefumi Jokura; Hidetoshi Ikeda; Reizo Shirane; Takashi Yoshimoto

    2001-01-01

    BACKGROUNDTranssphenoidal surgery is a safe procedure for treatment of pituitary adenomas. However, several complications, including post-surgical infection, are known. We describe a case of Aspergillus parasellar abscess that presented with cranial neuropathies following transsphenoidal surgery and radiosurgery. We initially diagnosed the case as radiation-induced neuropathies, which delayed the detection of Aspergillus.CASE DESCRIPTIONA 55-year-old man underwent transsphenoidal surgery for a pituitary

  3. Radiation-induced effects in acousto-optic devices

    Microsoft Academic Search

    Edward W. Taylor; Anthony D. Sanchez; Steve A. Dewalt; Richard J. Padden; S. P. Chapman; Tim W. Monarski; Douglas M. Craig; Daniel J. Page

    1993-01-01

    A brief report on an ongoing study concerned with the responses of acousto-optic modulators (AOMs) and deflectors (AODs) exposed to linearly accelerated electrons, gamma rays, and X rays is presented. The diffracted spatial intensities of PbMoO4, TeO2, and InP devices were observed to undergo displacements and attenuation. Discussions of radiation- induced temperature gradients and color center formation believed to be

  4. DNA Damage and Mutations Induced by Solar UV Radiation

    Microsoft Academic Search

    E. Sage

    \\u000a Exposure of individuals to sunlight creates DNA damage, and subsequently mutations, in actively dividing cells of the basal\\u000a layer of the epidermis. Mutations in oncogenes and tumor suppressor genes are crucial early events in the development of non-melanoma\\u000a skin tumors. The precise identification of DNA lesions and DNA sequence alterations induced by environmental solar UV radiation\\u000a in cultured cells represents

  5. Radiation induced degradation of fluorine containing elastomers at various temperatures

    Microsoft Academic Search

    Masayuki Ito

    1996-01-01

    This article studied the effect of temperature on the radiation induced degradation of fluorine containing elastomers, i.e. AFLAS type (Asahi glass Co. Ltd) and VITON type (Du pont). The temperature range is from 90 to 200°C. The irradiation was performed by 60Co ?-ray in air oven. Dose rate was 2.5 kGy\\/h. The weight loss by irradiation increases with increasing temperatures.

  6. Fault-tolerance memory system architecture for radiation induced errors

    NASA Technical Reports Server (NTRS)

    White, J. B., Jr.

    1982-01-01

    A fault-tolerant memory (FTM) architecture is presented which can be used to overcome soft memory errors induced by alpha particles, cosmic radiation, or other random sources. The characteristics of the FTM are presented, a mathematical model is developed, and numerical examples are considered to illustrate the effectiveness of the approach. The FTM architecture has been incorporated in the NASA Standard Spacecraft Computer (NSSC-II) which will be employed in a variety of future space payloads and experiments.

  7. Heat Induced Damage Detection by Terahertz (THz) Radiation

    Microsoft Academic Search

    Ehsan Kabiri Rahani; Tribikram Kundu; Ziran Wu; Hao Xin

    2011-01-01

    Terahertz (THz) and sub-terahertz imaging and spectroscopy are becoming increasingly popular nondestructive evaluation techniques\\u000a for damage detection and characterization of materials. THz radiation is being used for inspecting ceramic foam tiles used\\u000a in TPS (Thermal Protection System), thick polymer composites and polymer tiles that are not good conductors of ultrasonic\\u000a waves. Capability of THz electromagnetic waves in detecting heat induced

  8. Radiation-induced decomposition of PETN and TATB under pressure

    SciTech Connect

    Giefers, Hubertus; Pravica, Michael; Liermann, Hanns-Peter; Yang, Wenge (UNLV); (CIW)

    2008-10-02

    We have investigated decomposition of PETN and TATB induced by white synchrotron X-ray radiation in a diamond anvil cell at ambient temperature and two pressures, nearly ambient and about 6 GPa. The decomposition rate of TATB decreases significantly when it is pressurized to 5.9 GPa. The measurements were highly reproducible and allowed us to obtain decomposition rates and the order parameters of the reactions.

  9. Radiation-induced decomposition of PETN and TATB under pressure

    Microsoft Academic Search

    Hubertus Giefers; Michael Pravica; Hanns-Peter Liermann; Wenge Yang

    2006-01-01

    We have investigated decomposition of PETN and TATB induced by white synchrotron X-ray radiation in a diamond anvil cell at ambient temperature and two pressures, nearly ambient and about 6GPa. The decomposition rate of TATB decreases significantly when it is pressurized to 5.9GPa. The measurements were highly reproducible and allowed us to obtain decomposition rates and the order parameters of

  10. Probabilistic methodology for estimating radiation-induced cancer risk

    SciTech Connect

    Dunning, D.E. Jr.; Leggett, R.W.; Williams, L.R.

    1981-01-01

    The RICRAC computer code was developed at Oak Ridge National Laboratory to provide a versatile and convenient methodology for radiation risk assessment. The code allows as input essentially any dose pattern commonly encountered in risk assessments for either acute or chronic exposures, and it includes consideration of the age structure of the exposed population. Results produced by the analysis include the probability of one or more radiation-induced cancer deaths in a specified population, expected numbers of deaths, and expected years of life lost as a result of premature fatalities. These calculatons include consideration of competing risks of death from all other causes. The program also generates a probability frequency distribution of the expected number of cancers in any specified cohort resulting from a given radiation dose. The methods may be applied to any specified population and dose scenario.

  11. Radiation-induced bystander effect: early process and rapid assessment.

    PubMed

    Wang, Hongzhi; Yu, K N; Hou, Jue; Liu, Qian; Han, Wei

    2015-01-01

    Radiation-induced bystander effect (RIBE) is a biological process that has received attention over the past two decades. RIBE refers to a plethora of biological effects in non-irradiated cells, including induction of genetic damages, gene expression, cell transformation, proliferation and cell death, which are initiated by receiving bystander signals released from irradiated cells. RIBE brings potential hazards to normal tissues in radiotherapy, and imparts a higher risk from low-dose radiation than we previously thought. Detection with proteins related to DNA damage and repair, cell cycle control, proliferation, etc. have enabled rapid assessment of RIBE in a number of research systems such as cultured cells, three-dimensional tissue models and animal models. Accumulated experimental data have suggested that RIBE may be initiated rapidly within a time frame as short as several minutes after radiation. These have led to the requirement of techniques capable of rapidly assessing RIBE itself as well as assessing the early processes involved. PMID:24139967

  12. Residual stress induced crystalline to amorphous phase transformation in Nb{sub 2}O{sub 5} quantum dots

    SciTech Connect

    Dhawan, Sahil; Vedeshwar, Agnikumar G. [Thin Film Laboratory, Department of Physics and Astrophysics, University of Delhi, Delhi 110007 (India); Dhawan, Tanuj, E-mail: tanuj-physics@yahoo.com [Department of Physics and Electronics, Hans Raj College, University of Delhi, Delhi 110007 (India)

    2014-07-28

    Nb{sub 2}O{sub 5} quantum dots (QDs) were grown using a simple technique of vacuum thermal evaporation. QDs were found to be crystalline in nature by selected area electron diffraction (SAED) in TEM. Samples with thickness up to 20?nm did not show any significant residual strain. Residual stress effect on band gap of crystalline Nb{sub 2}O{sub 5} was studied for films thicker than 20?nm. Residual strain was determined using SAED of the films with reference to powder X-ray diffraction (XRD). Films thicker than 45?nm become amorphous as analyzed by both SAED and XRD. The optical absorption of films in the range 25–60?nm indicates significantly varying optical band gap of films. The varying band gap with film thickness scales linearly very well with the variation of residual stress with film thickness. The residual stress dependence of band gap of crystalline films yields stress free band gap as 3.37 eV with pressure coefficient of band gap (?E{sub g}/?P){sub T}?=??29.3?meV/GPa. From this study, the crystalline to amorphous transformation in tetragonal form of M-Nb{sub 2}O{sub 5} has been determined to be at about 14?GPa. Both pressure coefficient of band gap and crystalline to amorphous transition for tetragonal M-Nb{sub 2}O{sub 5} have been determined for the first time in the literature.

  13. Opportunities for nutritional amelioration of radiation-induced cellular damage

    NASA Technical Reports Server (NTRS)

    Turner, Nancy D.; Braby, Leslie A.; Ford, John; Lupton, Joanne R.

    2002-01-01

    The closed environment and limited evasive capabilities inherent in space flight cause astronauts to be exposed to many potential harmful agents (chemical contaminants in the environment and cosmic radiation exposure). Current power systems used to achieve space flight are prohibitively expensive for supporting the weight requirements to fully shield astronauts from cosmic radiation. Therefore, radiation poses a major, currently unresolvable risk for astronauts, especially for long-duration space flights. The major detrimental radiation effects that are of primary concern for long-duration space flights are damage to the lens of the eye, damage to the immune system, damage to the central nervous system, and cancer. In addition to the direct damage to biological molecules in cells, radiation exposure induces oxidative damage. Many natural antioxidants, whether consumed before or after radiation exposure, are able to confer some level of radioprotection. In addition to achieving beneficial effects from long-known antioxidants such as vitamins E and C and folic acid, some protection is conferred by several recently discovered antioxidant molecules, such as flavonoids, epigallocatechin, and other polyphenols. Somewhat counterintuitive is the protection provided by diets containing elevated levels of omega-3 polyunsaturated fatty acids, considering they are thought to be prone to peroxidation. Even with the information we have at our disposal, it will be difficult to predict the types of dietary modifications that can best reduce the risk of radiation exposure to astronauts, those living on Earth, or those enduring diagnostic or therapeutic radiation exposure. Much more work must be done in humans, whether on Earth or, preferably, in space, before we are able to make concrete recommendations.

  14. UV radiation induces CXCL5 expression in human skin.

    PubMed

    Reichert, Olga; Kolbe, Ludger; Terstegen, Lara; Staeb, Franz; Wenck, Horst; Schmelz, Martin; Genth, Harald; Kaever, Volkhard; Roggenkamp, Dennis; Neufang, Gitta

    2015-04-01

    CXCL5 has recently been identified as a mediator of UVB-induced pain in rodents. To compare and to extend previous knowledge of cutaneous CXCL5 regulation, we performed a comprehensive study on the effects of UV radiation on CXCL5 regulation in human skin. Our results show a dose-dependent increase in CXCL5 protein in human skin after UV radiation. CXCL5 can be released by different cell types in the skin. We presumed that, in addition to immune cells, non-immune skin cells also contribute to UV-induced increase in CXCL5 protein. Analysis of monocultured dermal fibroblasts and keratinocytes revealed that only fibroblasts but not keratinocytes displayed up regulated CXCL5 levels after UV stimulation. Whereas UV treatment of human skin equivalents, induced epidermal CXCL5 mRNA and protein expression. Up regulation of epidermal CXCL5 was independent of keratinocyte differentiation and keratinocyte-keratinocyte interactions in epidermal layers. Our findings provide first evidence on the release of CXCL5 in UV-radiated human skin and the essential role of fibroblast-keratinocyte interaction in the regulation of epidermal CXCL5. PMID:25690483

  15. Mechanisms of radiation-induced defect generation in fused silica

    NASA Astrophysics Data System (ADS)

    Natura, Ute; Sohr, Oliver; Martin, Rolf; Kahlke, Michael; Fasold, Gabriele

    2004-06-01

    Excimer laser radiation changes the optical properties of fused silica. These changes include radiation induced absorption and changes of the index of refraction, which in turn determine the expected lifetime of silica lenses used in optical microlithography. A fully automated experimental setup designed for the marathon exposure of samples at low energy densities was employed. Measurements of the induced absorption, of the H2 content using Raman spectroscopy as well as wavefront measurements were performed. A model to predict the aging behavior of silica in optical microlithography systems due to defect generation has been developed for both ArF laser irradiation and KrF laser irradiation. The model includes linear and nonlinear defect generation, relaxation processes and the consumption of hydrogen and describes the radiation induced changes of the index of refraction, the increase as well as the decrease. The model calculations were derived by analytical and numerical methods. A very good agreement in the range of parameters used in the experiments is observed.

  16. Delayed Diagnosis of Probable Radiation Induced Spinal Cord Vascular Disorders

    PubMed Central

    Won, Young Il; Chung, Chun Kee; Yun, Tae Jin

    2015-01-01

    Occasionally, unexpected neurological deficits occur after lumbar spinal surgery. We report a case of monoparesis after lumbar decompressive surgery. A 63-year-old man, who had undergone decompression of L4-5 for spinal stenosis 4 days previously in the other hospital, visted the emergency department with progressive weakness in the left leg and hypoesthesia below sensory level T7 on the right side. He had been cured of lung cancer with chemotherapy and radiation therapy 10 years previously, but detailed information of radiotherapy was not available. Whole spine magnetic resonance (MR) imaging showed fatty marrow change from T1 to T8, most likely due to previous irradiation. The T2-weighted MR image showed a high-signal T4-5 spinal cord lesion surrounded by a low signal rim, and the T1-weighted MR image showed focal high signal intensity with focal enhancement. The radiological diagnosis was vascular disorders with suspicious bleeding. Surgical removal was refused by the patient. With rehabilitation, the patient could walk independently without assistance 2 months later. Considering radiation induced change at thoracic vertebrae, vascular disorders may be induced by irradiation. If the spinal cord was previously irradiated, radiation induced vascular disorders needs to be considered. PMID:25810864

  17. Environmental applications of radiation-induced defects in clay minerals

    NASA Astrophysics Data System (ADS)

    Allard, T.

    2011-12-01

    Radiation effects on clay minerals have been studied over the last 35 years, providing a wealth of information on environmental and geological processes. They have been applied to the reconstruction of past radioelement migrations in the geosphere, the dating of clay minerals from soils or the evolution of the physico-chemical properties under irradiation. All known radiation-induced point defects in clay minerals are detected using Electron Paramagnetic Resonance Spectroscopy. They mostly consist in electron holes located on oxygen atoms of the structure, and can be differentiated through their nature and their thermal stability. For instance, several are associated to a ? orbital on a Si-O bond. One defect, namely the A-center, is stable over geological periods at ambiant temperature. These point defects are produced mainly by ionizing radiations. By contrast to point defects, it was shown that electron or heavy ion irradiation easily produces amorphization in smectites. Two main applications of radiation-induced defects in clay minerals are derived : (i) the use of defects as tracers of past radioactivity. In geosystems where the age of the clay can be constrained, migrations of radioelements can be reconstructed in natural analogues of the far field of high level nuclear waste repositories. When the dose rate may be assumed constant over time, the paleodose is used to date clay populations, an approach applied to laterites of the Amazon basin. (ii) The influence of radiation on clay mineral properties that remains poorly documented, although it is an important issue in various domains such as the safety assessment of the high level nuclear waste repositories. In case of a leakage of transuranic elements from the radioactive wasteform, alpha recoil nuclei would amorphize smectite after a period much lower than the disposal lifetime. By contrast, amorphisation from ionizing radiation is unlikely over 1 million years. Furthermore, it was shown that amorphization greatly enhances the dissolution kinetics of smectite, a result that must be taken into account in the safety assessment of engineered barriers.

  18. Liquid-crystalline self-organization of isocyanide-containing dendrimers induced by coordination to gold(I) fragments.

    PubMed

    Cordovilla, Carlos; Coco, Silverio; Espinet, Pablo; Donnio, Bertrand

    2010-02-01

    Dendritic polyisocyanides can be considered as promising polytopic ligands to generate a great diversity of metallodendrimers due to the ability of the isocyanide moiety to bind to various transition metals. Here, new isocyanide-containing dendrimers and their corresponding polynuclear gold complexes have been prepared, [G(i)(NC)(Z)] and [G(i)(NCAuR)(Z)], respectively, where G(i) is a poly(phenyl ether) dendrimer, i is the generation number (i = 0, 1, or 2), Z is the number of peripheral groups (Z = 3 x 2(i)), and AuR are the surface groups ([R = Cl, C[triple bond]C-C(6)H(4)-OC(12)H(25), C[triple bond]CC(6)H(2)(OC(12)H(25))(3)]. The compounds are derived from a highly flexible phenyl ether-based dendritic core, G(i), having the general formula G(0) = C(6)H(3)(OC(11)H(22)OC(6)H(4)-)(3), G(1) = C(6)H(3)[OC(11)H(22)OC(6)H(3)(OC(11)H(22)OC(6)H(4)-)(2)](3), G(2) = C(6)H(3)[OC(11)H(22)OC(6)H(3){OC(11)H(22)OC(6)H(3)(OC(11)H(22)OC(6)H(4)-)(2)}(2)](3)), growing from the trivalent phloroglucinol and with undecylene aliphatic spacers between each branching benzene ring and end-functionalized by isocyanide groups. As in their monomeric model counterparts, stable liquid-crystalline phases are induced upon complexation of the AuR gold moieties at the branch termini. The nature of the anionic ligand R promotes the appearance of smectic or columnar mesophases, the formation of which are governed by steric and dipolar interactions. Based on X-ray diffraction experiments, models describing the supramolecular organization of these metallodendrimers into smectic and columnar mesophases are proposed: columnar phases result from the one-dimensional stacking of molecular disks made of self-assembled supermolecules in oblate cylindrical conformation, while the smectic phases form by the lateral two-dimensional registry of the supermolecules in antiparallel head-to-head prolate conformation. PMID:20055502

  19. Radiation induced bystander effects: Implications for low dose radiation risk assessment

    NASA Astrophysics Data System (ADS)

    Zhou, H.; Suzuki, M.; Randers-Pehrson, G.; Waldren, C.; Hei, T.

    Current model used in radiation risk assessment is based on the dogma that the DNA of the nucleus is the main target for radiation-induced genotoxicity and, as fewer cells are directly damaged at low doses, the deleterious effects of radiation proportionally decline. Using a precision microbeam to target an exact fraction of cells in a population and irradiated their nuclei with exactly one alpha particle each, we found that the frequencies of induced mutations and chromosomal changes in populations where some known fractions of nuclei were hit are consistent with non- hit cells contributing significantly to the response. In fact, irradiation of 10% of a mammalian cell population with a single alpha particle per cell results in a mutant yield similar to that observed when all of the cells in the population are irradiated. This effect was significantly eliminated in cells pretreated with gap junction inhibitor or in cells carrying a dominant negative connexin 43 vector. The data imply that the relevant target for radiation mutagenesis is larger than an individual cell and suggest a need to reconsider the validity of the linear extrapolation in making risk estimate for low dose radiation exposure.

  20. Radiation Induced Bystander Effects in Mice Given Low Doses of Radiation in Vivo

    PubMed Central

    Singh, Harleen; Saroya, Rohin; Smith, Richard; Mantha, Rebecca; Guindon, Lynda; Mitchel, Ron E.J.; Seymour, Colin; Mothersill, Carmel

    2010-01-01

    The ‘bystander effect’ phenomenon has challenged the traditional framework for assessing radiation damage by showing radiation induced changes in cells which have not been directly targeted, but are neighbors to or receive medium from directly hit cells. Our group performed a range of single and serial low dose irradiations on two genetically distinct strains of mice. Bladder explants established from these mice were incubated in culture medium, which was used to measure death responses in a keratinocyte reporter system. The study revealed that the medium harvested from bladder tissues’ (ITCM) from acutely irradiated C57BL6 but not Balb/c mice, was able to induce clonogenic death. Administration of a priming dose(s) before a challenge dose to both C57BL6 and Balb/c mice stimulated reporter cell survival irrespective of the time interval between dose(s) delivery. When ITCM corresponding to both strains of mice was measured for its calcium mobilization inducing ability, results showed an elevation in intracellular calcium levels that was strain dependent. This indicates that genotype determined the type of bystander signal/response that was produced after exposure to low and acute doses of radiation. However, serial exposure conditions modified bystander signal production to induce similar effects that were characterized by excessive growth. PMID:21731538

  1. Radiation induced genome instability: multiscale modelling and data analysis

    NASA Astrophysics Data System (ADS)

    Andreev, Sergey; Eidelman, Yuri

    2012-07-01

    Genome instability (GI) is thought to be an important step in cancer induction and progression. Radiation induced GI is usually defined as genome alterations in the progeny of irradiated cells. The aim of this report is to demonstrate an opportunity for integrative analysis of radiation induced GI on the basis of multiscale modelling. Integrative, systems level modelling is necessary to assess different pathways resulting in GI in which a variety of genetic and epigenetic processes are involved. The multilevel modelling includes the Monte Carlo based simulation of several key processes involved in GI: DNA double strand breaks (DSBs) generation in cells initially irradiated as well as in descendants of irradiated cells, damage transmission through mitosis. Taking the cell-cycle-dependent generation of DNA/chromosome breakage into account ensures an advantage in estimating the contribution of different DNA damage response pathways to GI, as to nonhomologous vs homologous recombination repair mechanisms, the role of DSBs at telomeres or interstitial chromosomal sites, etc. The preliminary estimates show that both telomeric and non-telomeric DSB interactions are involved in delayed effects of radiation although differentially for different cell types. The computational experiments provide the data on the wide spectrum of GI endpoints (dicentrics, micronuclei, nonclonal translocations, chromatid exchanges, chromosome fragments) similar to those obtained experimentally for various cell lines under various experimental conditions. The modelling based analysis of experimental data demonstrates that radiation induced GI may be viewed as processes of delayed DSB induction/interaction/transmission being a key for quantification of GI. On the other hand, this conclusion is not sufficient to understand GI as a whole because factors of DNA non-damaging origin can also induce GI. Additionally, new data on induced pluripotent stem cells reveal that GI is acquired in normal mature cells during genome reprogramming by the oncogene c-myc and three additional transcription factors. These and other data reveal the need for generalisation of current model of GI. One can expect that different early events of both DNA damaging and non-damaging origins merge in a single late pathway. To search for a deeper view we propose to redefine GI as genome destabilisation manifested in erosion of genome states and altered transitions between states. This changing view on GI may help to integrate the inducing factors of various origins in the single basic model of GI.

  2. Protection of T cells from radiation-induced apoptosis by Cepharanthin®

    Microsoft Academic Search

    Haruki Oyaizu; Yasushi Adachi; Ryoji Yasumizu; Minoru Ono; Kazuya Ikebukuro; Shirou Fukuhara; Susumu Ikehara

    2001-01-01

    Cepharanthin® (CE) is a medicine that contains several biscoclaurine alkaloids. We examined the effects of CE on radiation-induced T cell apoptosis. Radiation induced apoptosis on T cells in a dose-dependent manner, while CE inhibited radiation-induced apoptosis. CE also attenuated the cytotoxic effects of radiation on the proliferative response of T cells. CE inhibited not only the loss of mitochondrial transmembrane

  3. Quantifying Local Radiation-Induced Lung Damage From Computed Tomography

    SciTech Connect

    Ghobadi, Ghazaleh; Hogeweg, Laurens E. [Department of Radiation Oncology, University Medical Center Groningen/University of Groningen, Groningen (Netherlands); Faber, Hette [Department of Radiation Oncology, University Medical Center Groningen/University of Groningen, Groningen (Netherlands); Department of Cell Biology, Section of Radiation and Stress Cell Biology, University Medical Center Groningen/University of Groningen, Groningen (Netherlands); Tukker, Wim G.J. [Department of Radiology, University Medical Center Groningen/University of Groningen, Groningen (Netherlands); Schippers, Jacobus M. [Department of Radiation Oncology, University Medical Center Groningen/University of Groningen, Groningen (Netherlands); Accelerator Department, Paul Scherrer Institut, Villigen (Switzerland); Brandenburg, Sytze [Kernfysisch Versneller Instituut, Groningen (Netherlands); Langendijk, Johannes A. [Department of Radiation Oncology, University Medical Center Groningen/University of Groningen, Groningen (Netherlands); Coppes, Robert P. [Department of Radiation Oncology, University Medical Center Groningen/University of Groningen, Groningen (Netherlands); Department of Cell Biology, Section of Radiation and Stress Cell Biology, University Medical Center Groningen/University of Groningen, Groningen (Netherlands); Luijk, Peter van, E-mail: p.van.luijk@rt.umcg.n [Department of Radiation Oncology, University Medical Center Groningen/University of Groningen, Groningen (Netherlands)

    2010-02-01

    Purpose: Optimal implementation of new radiotherapy techniques requires accurate predictive models for normal tissue complications. Since clinically used dose distributions are nonuniform, local tissue damage needs to be measured and related to local tissue dose. In lung, radiation-induced damage results in density changes that have been measured by computed tomography (CT) imaging noninvasively, but not yet on a localized scale. Therefore, the aim of the present study was to develop a method for quantification of local radiation-induced lung tissue damage using CT. Methods and Materials: CT images of the thorax were made 8 and 26 weeks after irradiation of 100%, 75%, 50%, and 25% lung volume of rats. Local lung tissue structure (S{sub L}) was quantified from local mean and local standard deviation of the CT density in Hounsfield units in 1-mm{sup 3} subvolumes. The relation of changes in S{sub L} (DELTAS{sub L}) to histologic changes and breathing rate was investigated. Feasibility for clinical application was tested by applying the method to CT images of a patient with non-small-cell lung carcinoma and investigating the local dose-effect relationship of DELTAS{sub L}. Results: In rats, a clear dose-response relationship of DELTAS{sub L} was observed at different time points after radiation. Furthermore, DELTAS{sub L} correlated strongly to histologic endpoints (infiltrates and inflammatory cells) and breathing rate. In the patient, progressive local dose-dependent increases in DELTAS{sub L} were observed. Conclusion: We developed a method to quantify local radiation-induced tissue damage in the lung using CT. This method can be used in the development of more accurate predictive models for normal tissue complications.

  4. Radiation-Induced Leukemia at Doses Relevant to Radiation Therapy: Modeling Mechanisms and Estimating Risks

    NASA Technical Reports Server (NTRS)

    Shuryak, Igor; Sachs, Rainer K.; Hlatky, Lynn; Mark P. Little; Hahnfeldt, Philip; Brenner, David J.

    2006-01-01

    Because many cancer patients are diagnosed earlier and live longer than in the past, second cancers induced by radiation therapy have become a clinically significant issue. An earlier biologically based model that was designed to estimate risks of high-dose radiation induced solid cancers included initiation of stem cells to a premalignant state, inactivation of stem cells at high radiation doses, and proliferation of stem cells during cellular repopulation after inactivation. This earlier model predicted the risks of solid tumors induced by radiation therapy but overestimated the corresponding leukemia risks. Methods: To extend the model to radiation-induced leukemias, we analyzed in addition to cellular initiation, inactivation, and proliferation a repopulation mechanism specific to the hematopoietic system: long-range migration through the blood stream of hematopoietic stem cells (HSCs) from distant locations. Parameters for the model were derived from HSC biologic data in the literature and from leukemia risks among atomic bomb survivors v^ ho were subjected to much lower radiation doses. Results: Proliferating HSCs that migrate from sites distant from the high-dose region include few preleukemic HSCs, thus decreasing the high-dose leukemia risk. The extended model for leukemia provides risk estimates that are consistent with epidemiologic data for leukemia risk associated with radiation therapy over a wide dose range. For example, when applied to an earlier case-control study of 110000 women undergoing radiotherapy for uterine cancer, the model predicted an excess relative risk (ERR) of 1.9 for leukemia among women who received a large inhomogeneous fractionated external beam dose to the bone marrow (mean = 14.9 Gy), consistent with the measured ERR (2.0, 95% confidence interval [CI] = 0.2 to 6.4; from 3.6 cases expected and 11 cases observed). As a corresponding example for brachytherapy, the predicted ERR of 0.80 among women who received an inhomogeneous low-dose-rate dose to the bone marrow (mean = 2.5 Gy) was consistent with the measured ERR (0.62, 95% Cl =-0.2 to 1.9). Conclusions: An extended, biologically based model for leukemia that includes HSC initiation, inactivation, proliferation, and, uniquely for leukemia, long-range HSC migration predicts, %Kith reasonable accuracy, risks for radiationinduced leukemia associated with exposure to therapeutic doses of radiation.

  5. Radiation-induced electron migration in nucleic acids.

    PubMed

    Fuciarelli, A F; Sisk, E C; Miller, J H; Zimbrick, J D

    1994-11-01

    Radiation-induced electron migration along DNA is a mechanism by which randomly produced stochastic energy deposition events can lead to non-random types of damage along DNA manifested distal to the sites of the initial energy deposition. Radiation-induced electron migration in nucleic acids has been examined using oligonucleotides containing 5-bromouracil (5-BrU). Interaction of 5-BrU with solvated electrons results in release of bromide ions and formation or uracil-5-yl radicals. Monitoring either bromide ion release or uracil formation provides an opportunity to study electron migration processes in model nucleic acid systems. Using this approach we have discovered that electron migration along oligonucleotides is significantly influenced by the base sequence and strandedness. Migration along 7 base pairs in oligonucleotides containing guanine bases was observed for oligonucleotides irradiated in solution, which compares with mean migration distances of 6-10 bp for Escherichia coli DNA irradiated in solution and 5.5 bp for E. coli DNA irradiated in cells. Evidence also suggests that electron migration can occur preferentially in the 5' to 3' direction along a double-stranded oligonucleotide containing a region of purine bases adjacent to the 5-BrU moiety. Our continued efforts will provide information regarding the contribution of electron transfer along DNA to formation of locally multiply damaged sites created in DNA by exposure to ionizing radiation. PMID:7983438

  6. Sensitization of ionizing radiation-induced apoptosis by ursolic acid.

    PubMed

    Koh, Su Jin; Tak, Jean Kyoung; Kim, Seon Tae; Nam, Woo Suk; Kim, Sung Youl; Park, Kwon Moo; Park, Jeen-Woo

    2012-03-01

    Radiation therapy has been widely used for treating human cancers. However, cancer cells develop radioresistant phenotypes that decrease the efficacy of radiotherapy. Ionizing radiation (IR) induces the production of reactive oxygen species, which play an important role in apoptotic cell death. Therefore, radiation therapy combined with a sensitizer, which modulates cellular redox status, has the potential to enhance therapeutic efficacy in a variety of human cancers. Here, we investigated the radiosensitizing effects of ursolic acid (UA), a pentacyclic triterpenoid found in rosemary and holy basil. IR-induced apoptosis in cancer cell lines such as DU145, CT26 and B16F10 was significantly enhanced by UA, as reflected by DNA fragmentation, cellular redox status, mitochondrial dysfunction and modulation of apoptotic marker proteins. Additionally, UA combined with IR was also effective for inhibiting tumorigenesis in B16F10 melanoma cells implanted into mice. Taken together, these results suggest that applying UA together with IR may be an effective combination modality for treating cancer. PMID:22239065

  7. Pharmacological Protection From Radiation {+-} Cisplatin-Induced Oral Mucositis

    SciTech Connect

    Cotrim, Ana P. [Molecular Physiology and Therapeutics Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD (United States); Yoshikawa, Masanobu [Molecular Physiology and Therapeutics Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD (United States); Department of Clinical Pharmacology, Tokai University School of Medicine, Kanagawa (Japan); Sunshine, Abraham N.; Zheng Changyu [Molecular Physiology and Therapeutics Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD (United States); Sowers, Anastasia L.; Thetford, Angela D.; Cook, John A.; Mitchell, James B. [Radiation Biology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD (United States); Baum, Bruce J., E-mail: bbaum@dir.nidcr.nih.gov [Molecular Physiology and Therapeutics Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD (United States)

    2012-07-15

    Purpose: To evaluate if two pharmacological agents, Tempol and D-methionine (D-met), are able to prevent oral mucositis in mice after exposure to ionizing radiation {+-} cisplatin. Methods and Materials: Female C3H mice, {approx}8 weeks old, were irradiated with five fractionated doses {+-} cisplatin to induce oral mucositis (lingual ulcers). Just before irradiation and chemotherapy, mice were treated, either alone or in combination, with different doses of Tempol (by intraperitoneal [ip] injection or topically, as an oral gel) and D-met (by gavage). Thereafter, mice were sacrificed and tongues were harvested and stained with a solution of Toluidine Blue. Ulcer size and tongue epithelial thickness were measured. Results: Significant lingual ulcers resulted from 5 Multiplication-Sign 8 Gy radiation fractions, which were enhanced with cisplatin treatment. D-met provided stereospecific partial protection from lingual ulceration after radiation. Tempol, via both routes of administration, provided nearly complete protection from lingual ulceration. D-met plus a suboptimal ip dose of Tempol also provided complete protection. Conclusions: Two fairly simple pharmacological treatments were able to markedly reduce chemoradiation-induced oral mucositis in mice. This proof of concept study suggests that Tempol, alone or in combination with D-met, may be a useful and convenient way to prevent the severe oral mucositis that results from head-and-neck cancer therapy.

  8. DNA damage in cells exhibiting radiation-induced genomic instability.

    PubMed

    Keszenman, Deborah J; Kolodiuk, Lucia; Baulch, Janet E

    2015-05-01

    Cells exhibiting radiation-induced genomic instability exhibit varied spectra of genetic and chromosomal aberrations. Even so, oxidative stress remains a common theme in the initiation and/or perpetuation of this phenomenon. Isolated oxidatively modified bases, abasic sites, DNA single strand breaks and clustered DNA damage are induced in normal mammalian cultured cells and tissues due to endogenous reactive oxygen species generated during normal cellular metabolism in an aerobic environment. While sparse DNA damage may be easily repaired, clustered DNA damage may lead to persistent cytotoxic or mutagenic events that can lead to genomic instability. In this study, we tested the hypothesis that DNA damage signatures characterised by altered levels of endogenous, potentially mutagenic, types of DNA damage and chromosomal breakage are related to radiation-induced genomic instability and persistent oxidative stress phenotypes observed in the chromosomally unstable progeny of irradiated cells. The measurement of oxypurine, oxypyrimidine and abasic site endogenous DNA damage showed differences in non-double-strand breaks (DSB) clusters among the three of the four unstable clones evaluated as compared to genomically stable clones and the parental cell line. These three unstable clones also had increased levels of DSB clusters. The results of this study demonstrate that each unstable cell line has a unique spectrum of persistent damage and lead us to speculate that alterations in DNA damage signaling and repair may be related to the perpetuation of genomic instability. PMID:25711497

  9. Cerenkov emission induced by external beam radiation stimulates molecular fluorescence

    SciTech Connect

    Axelsson, Johan; Davis, Scott C.; Gladstone, David J.; Pogue, Brian W. [Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire 03755 (United States); Norris Cotton Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire 03766 (United States); Thayer School of Engineering and Department of Physics and Astronomy, Dartmouth College, Hanover, New Hampshire 03755 (United States)

    2011-07-15

    Purpose: Cerenkov emission is induced when a charged particle moves faster than the speed of light in a given medium. Both x-ray photons and electrons produce optical Cerenkov photons in everyday radiation therapy of tissue; yet, this phenomenon has never been fully documented. This study quantifies the emissions and also demonstrates that the Cerenkov emission can excite a fluorophore, protoporphyrin IX (PpIX), embedded in biological phantoms. Methods: In this study, Cerenkov emission induced by radiation from a clinical linear accelerator is investigated. Biological mimicking phantoms were irradiated with x-ray photons, with energies of 6 or 18 MV, or electrons at energies 6, 9, 12, 15, or 18 MeV. The Cerenkov emission and the induced molecular fluorescence were detected by a camera or a spectrometer equipped with a fiber optic cable. Results: It is shown that both x-ray photons and electrons, at MeV energies, produce optical Cerenkov photons in tissue mimicking media. Furthermore, we demonstrate that the Cerenkov emission can excite a fluorophore, protoporphyrin IX (PpIX), embedded in biological phantoms. Conclusions: The results here indicate that molecular fluorescence monitoring during external beam radiotherapy is possible.

  10. TransDifferentiation of Neural Stem Cells: A Therapeutic Mechanism Against the Radiation Induced Brain Damage

    Microsoft Academic Search

    Kyeung Min Joo; Juyoun Jin; Bong Gu Kang; Se Jeong Lee; Kang Ho Kim; Heekyoung Yang; Young-Ae Lee; Yu Jin Cho; Yong-Seok Im; Dong-Sup Lee; Do-Hoon Lim; Dong Hyun Kim; Hong-Duck Um; Sang-Hun Lee; Jung-II Lee; Do-Hyun Nam

    2012-01-01

    Radiation therapy is an indispensable therapeutic modality for various brain diseases. Though endogenous neural stem cells (NSCs) would provide regenerative potential, many patients nevertheless suffer from radiation-induced brain damage. Accordingly, we tested beneficial effects of exogenous NSC supplementation using in vivo mouse models that received whole brain irradiation. Systemic supplementation of primarily cultured mouse fetal NSCs inhibited radiation-induced brain atrophy

  11. The Development of Countermeasures for Space Radiation Induced Adverse Health Effects

    Microsoft Academic Search

    Ann Kennedy

    2010-01-01

    The Development of Countermeasures for Space Radiation Induced Adverse Health Effects Ann R. Kennedy Department of Radiation Oncology, University of Pennsylvania School of Medicine, 195 John Morgan Building, 3620 Hamilton Walk, Philadelphia, PA, United States 19104-6072 The development of countermeasures for radiation induced adverse health effects is a lengthy process, particularly when the countermeasure\\/drug has not yet been evaluated in

  12. Experimental Radiation-Induced Heart Disease: Past, Present, and Future

    PubMed Central

    Boerma, Marjan

    2012-01-01

    Radiation-induced heart disease (RIHD) is a serious side effect of radiotherapy for intrathoracic and chest wall tumors. The threshold dose for development of clinically significant RIHD is believed to be lower than previously assumed. Therefore, research into mechanisms of RIHD has gained substantial momentum. RIHD becomes clinically apparent ten to fifteen years after radiation exposure. Chronic manifestations of RIHD include accelerated atherosclerosis, cardiomyopathy, and valve abnormalities. Reducing exposure of the heart during radiotherapy is the only known method of preventing RIHD, and there are no approaches to reverse RIHD once it occurs. We use a combination of pharmacological and genetic animal models to determine biological mechanisms of RIHD. Major technological advances in small animal research have made this type of study more valuable. The long-term goal of this work is to identify targets for intervention in RIHD, thereby enhancing the efficacy and safety of thoracic radiotherapy. PMID:22663150

  13. Erythrocyte Stiffness during Morphological Remodeling Induced by Carbon Ion Radiation

    PubMed Central

    Zhang, Baoping; Liu, Bin; Zhang, Hong; Wang, Jizeng

    2014-01-01

    The adverse effect induced by carbon ion radiation (CIR) is still an unavoidable hazard to the treatment object. Thus, evaluation of its adverse effects on the body is a critical problem with respect to radiation therapy. We aimed to investigate the change between the configuration and mechanical properties of erythrocytes induced by radiation and found differences in both the configuration and the mechanical properties with involving in morphological remodeling process. Syrian hamsters were subjected to whole-body irradiation with carbon ion beams (1, 2, 4, and 6 Gy) or X-rays (2, 4, 6, and 12 Gy) for 3, 14 and 28 days. Erythrocytes in peripheral blood and bone marrow were collected for cytomorphological analysis. The mechanical properties of the erythrocytes were determined using atomic force microscopy, and the expression of the cytoskeletal protein spectrin-?1 was analyzed via western blotting. The results showed that dynamic changes were evident in erythrocytes exposed to different doses of carbon ion beams compared with X-rays and the control (0 Gy). The magnitude of impairment of the cell number and cellular morphology manifested the subtle variation according to the irradiation dose. In particular, the differences in the size, shape and mechanical properties of the erythrocytes were well exhibited. Furthermore, immunoblot data showed that the expression of the cytoskeletal protein spectrin-?1 was changed after irradiation, and there was a common pattern among its substantive characteristics in the irradiated group. Based on these findings, the present study concluded that CIR could induce a change in mechanical properties during morphological remodeling of erythrocytes. According to the unique characteristics of the biomechanical categories, we deduce that changes in cytomorphology and mechanical properties can be measured to evaluate the adverse effects generated by tumor radiotherapy. Additionally, for the first time, the current study provides a new strategy for enhancing the assessment of the curative effects and safety of clinical radiotherapy, as well as reducing adverse effects. PMID:25401336

  14. Measurements of prompt radiation induced conductivity of Kapton.

    SciTech Connect

    Preston, Eric F. (ITT Corporation, Colorado Springs, CO); Zarick, Thomas Andrew; Sheridan, Timothy J.; Hartman, E. Frederick; Stringer, Thomas Arthur (ITT Corporation, Colorado Springs, CO)

    2010-10-01

    We performed measurements of the prompt radiation induced conductivity in thin samples of Kapton (polyimide) at the Little Mountain Medusa LINAC facility in Ogden, UT. Three mil samples were irradiated with a 0.5 {mu}s pulse of 20 MeV electrons, yielding dose rates of 1E9 to 1E10 rad/s. We applied variable potentials up to 2 kV across the samples and measured the prompt conduction current. Analysis rendered prompt conductivity coefficients between 6E-17 and 2E-16 mhos/m per rad/s, depending on the dose rate and the pulse width.

  15. Radiation-Induced Premelting of Ice at Silica Interfaces

    SciTech Connect

    Schoeder, S. [Max-Planck-Institut fuer Metallforschung, Heisenbergstrasse 3, 70569 Stuttgart (Germany); European Synchrotron Radiation Facility (ESRF), 38043 Grenoble (France); Reichert, H.; Schroeder, H.; Mezger, M.; Okasinski, J. S.; Dosch, H. [Max-Planck-Institut fuer Metallforschung, Heisenbergstrasse 3, 70569 Stuttgart (Germany); Honkimaeki, V. [European Synchrotron Radiation Facility (ESRF), 38043 Grenoble (France); Bilgram, J. [Laboratorium fuer Festkoerperphysik, ETH Zuerich, 8093 Zuerich (Switzerland)

    2009-08-28

    The existence of surface and interfacial melting of ice below 0 deg. C has been confirmed by many different experimental techniques. Here we present a high-energy x-ray reflectivity study of the interfacial melting of ice as a function of both temperature and x-ray irradiation dose. We found a clear increase of the thickness of the quasiliquid layer with the irradiation dose. By a systematic x-ray study, we have been able to unambiguously disentangle thermal and radiation-induced premelting phenomena. We also confirm the previously announced very high water density (1.25 g/cm{sup 3}) within the emerging quasiliquid layer.

  16. Facial reconstruction for radiation-induced skin cancer

    SciTech Connect

    Panje, W.R.; Dobleman, T.J. (Univ. of Chicago, IL (USA))

    1990-04-01

    Radiation-induced skin cancers can be difficult to diagnose and treat. Typically, a patient who has received orthovoltage radiotherapy for disorders such as acne, eczema, tinea capitis, skin tuberculosis, and skin cancer can expect that aggressive skin cancers and chronic radiodermatitis may develop subsequently. Cryptic facial cancers can lead to metastases and death. Prophylactic widefield excision of previously irradiated facial skin that has been subject to multiple recurrent skin cancers is suggested as a method of deterring future cutaneous malignancy and metastases. The use of tissue expanders and full-thickness skin grafts offers an expedient and successful method of subsequent reconstruction.

  17. Radiation-induced morphoea treated with UVA-1 phototherapy.

    PubMed

    Lim, D; Johnston, S; Novakovic, L; Fearfield, L

    2014-07-01

    Morphoea is a localized inflammatory disorder of the dermis and subcutaneous fat and radiotherapy is a rarely reported cause (estimated incidence of 2 per 1000). Morphoea is commonly mistaken for an inflammatory recurrence of breast cancer, resulting in unnecessary investigations and treatment. We report the case of a 40-year-old woman who developed radiation-induced morphoea of the breast 7 months following adjuvant radiotherapy. She was treated with topical and systemic steroids as well as psoralen plus ultraviolet (UV)A before proceeding to UVA1 phototherapy. We also review the literature and discuss other management options. PMID:24890985

  18. X-radiation-induced differentiation of xenotransplanted human undifferentiated rhabdomyosarcoma

    SciTech Connect

    Takizawa, T.; Matsui, T.; Maeda, Y.; Okabe, S.; Mochizuki, M.; Tanaka, A.; Kawaguchi, K.; Fukayama, M.; Funata, N.; Koike, M.

    1989-01-01

    A serially xenotransplantable strain of undifferentiated embryonal rhabdomyosarcoma originating from the nasal cavity of a 42-year-old woman has been established in our laboratory. After radiotherapy for the tumor donor, distinct rhabdomyoblastic differentiation of the undifferentiated sarcoma cells appeared in the primary lesion, and it is a reasonable assumption that X-irradiation has a certain potentiality to induce morphologic differentiation of tumor cells. To study this possibility, tissue fragments of undifferentiated embryonal rhabdomyosarcoma that had grown to more than 10 mm after being transplanted to nude mice were selectively irradiated in situ. The degree of rhabdomyoblastic differentiation according to radiation dose was evaluated by light and electron microscopy and by immunostainability for myoglobin, creatine phosphokinase-MM, and desmin. Distinct morphologic differentiation of undifferentiated sarcoma cells could be induced by repeated X-irradiations at several-week intervals.

  19. Method and apparatus for characterization of electric field-induced aggregation in pre-crystalline protein solutions

    NASA Astrophysics Data System (ADS)

    Wakamatsu, Takashi

    2015-01-01

    The article presents a method and an apparatus for the characterization of protein aggregation under an applied internal electric field. The method is based on a forward light scattering technique that is highly sensitive to aggregates in pre-crystalline protein solutions. Transparent conductive films are used as electrodes for a planar thin sample cell, which enables precise measurement of the forward light scattering at small angles through the electrodes. Evaluation of the protein aggregation under applied electric fields was demonstrated for a model lysozyme protein. In situ measurements of crystallizing lysozyme solutions under a low applied voltage revealed that the forward static light scattering profiles changed with time into power law profiles. This indicates the formation of lysozyme fractal clusters under applied electric fields in the pre-crystalline state. The method and the apparatus presented here can sensitively evaluate the promotion process in protein crystallization under an applied electric field.

  20. Lattice-based simulations of chain conformations in semi-crystalline polymers with application to flow-induced crystallization

    Microsoft Academic Search

    Jaydeep A. Kulkarni; Antony N. Beris

    1999-01-01

    Polymer fiber processes, such as high-speed spinning of nylon and PET, are highly complex involving a complicated interplay between an evolving internal molecular microstructure, macroscopic transport phenomena, such as fluid mechanics and heat transfer, and also non-equilibrium thermodynamics and kinetics affecting nucleation and subsequent crystal growth. All of the above processes are important in determining the final product's semi-crystalline morphology

  1. Field-Induced Crystalline-to-Amorphous Phase Transformation on the Si Nano-Apex and the Achieving of Highly Reliable Si Nano-Cathodes

    PubMed Central

    Huang, Yifeng; Deng, Zexiang; Wang, Weiliang; Liang, Chaolun; She, Juncong; Deng, Shaozhi; Xu, Ningsheng

    2015-01-01

    Nano-scale vacuum channel transistors possess merits of higher cutoff frequency and greater gain power as compared with the conventional solid-state transistors. The improvement in cathode reliability is one of the major challenges to obtain high performance vacuum channel transistors. We report the experimental findings and the physical insight into the field induced crystalline-to-amorphous phase transformation on the surface of the Si nano-cathode. The crystalline Si tip apex deformed to amorphous structure at a low macroscopic field (0.6~1.65 V/nm) with an ultra-low emission current (1~10 pA). First-principle calculation suggests that the strong electrostatic force exerting on the electrons in the surface lattices would take the account for the field-induced atomic migration that result in an amorphization. The arsenic-dopant in the Si surface lattice would increase the inner stress as well as the electron density, leading to a lower amorphization field. Highly reliable Si nano-cathodes were obtained by employing diamond like carbon coating to enhance the electron emission and thus decrease the surface charge accumulation. The findings are crucial for developing highly reliable Si-based nano-scale vacuum channel transistors and have the significance for future Si nano-electronic devices with narrow separation. PMID:25994377

  2. Field-Induced Crystalline-to-Amorphous Phase Transformation on the Si Nano-Apex and the Achieving of Highly Reliable Si Nano-Cathodes.

    PubMed

    Huang, Yifeng; Deng, Zexiang; Wang, Weiliang; Liang, Chaolun; She, Juncong; Deng, Shaozhi; Xu, Ningsheng

    2015-01-01

    Nano-scale vacuum channel transistors possess merits of higher cutoff frequency and greater gain power as compared with the conventional solid-state transistors. The improvement in cathode reliability is one of the major challenges to obtain high performance vacuum channel transistors. We report the experimental findings and the physical insight into the field induced crystalline-to-amorphous phase transformation on the surface of the Si nano-cathode. The crystalline Si tip apex deformed to amorphous structure at a low macroscopic field (0.6~1.65 V/nm) with an ultra-low emission current (1~10 pA). First-principle calculation suggests that the strong electrostatic force exerting on the electrons in the surface lattices would take the account for the field-induced atomic migration that result in an amorphization. The arsenic-dopant in the Si surface lattice would increase the inner stress as well as the electron density, leading to a lower amorphization field. Highly reliable Si nano-cathodes were obtained by employing diamond like carbon coating to enhance the electron emission and thus decrease the surface charge accumulation. The findings are crucial for developing highly reliable Si-based nano-scale vacuum channel transistors and have the significance for future Si nano-electronic devices with narrow separation. PMID:25994377

  3. In-Situ Measurement of Crystalline Silicon Modules Undergoing Potential-Induced Degradation in Damp Heat Stress Testing for Estimation of Low-Light Power Performance

    SciTech Connect

    Hacke, P.; Terwilliger, K.; Kurtz, S.

    2013-08-01

    The extent of potential-induced degradation of crystalline silicon modules in an environmental chamber is estimated using in-situ dark I-V measurements and applying superposition analysis. The dark I-V curves are shown to correctly give the module power performance at 200, 600 and 1,000 W/m2 irradiance conditions, as verified with a solar simulator. The onset of degradation measured in low light in relation to that under one sun irradiance can be clearly seen in the module design examined; the time to 5% relative degradation measured in low light (200 W/m2) was 28% less than that of full sun (1,000 W/m2 irradiance). The power of modules undergoing potential-induced degradation can therefore be characterized in the chamber, facilitating statistical analyses and lifetime forecasting.

  4. Radiation-induced bystander effects in vivo are sex specific.

    PubMed

    Koturbash, Igor; Kutanzi, Kristy; Hendrickson, Karl; Rodriguez-Juarez, Rocio; Kogosov, Dmitry; Kovalchuk, Olga

    2008-07-01

    Ionizing radiation (IR) effects span beyond the area of direct exposure and can be observed in neighboring and distant naïve cells and organs. This phenomenon is termed a 'bystander effect'. IR effects in directly exposed tissue in vivo are epigenetically mediated and distinct in males and females. Yet, IR-induced bystander effects have never been explored in a sex-specificity domain. We used an in vivo mouse model, whereby the bystander effects are studied in spleen of male and female animals subjected to head exposure when the rest of the body is protected by a medical-grade lead shield. We analyzed the induction of DNA damage and alterations in global DNA methylation. Molecular parameters were correlated with cellular proliferation and apoptosis levels. The changes observed in bystander organs are compared to the changes in unexposed animals and animals exposed to predicted and measured scatter doses. We have found the selective induction of DNA damage levels, global DNA methylation, cell proliferation and apoptosis in exposed and bystander spleen tissue of male and female mice. Sex differences were significantly diminished in animals subjected to a surgical removal of gonads. These data constitute the first evidence of sex differences in radiation-induced bystander effects in mouse spleen in vivo. We show the role of sex hormones in spleen bystander responses and discuss implications of the observed changes. PMID:18508093

  5. [Studies on chemical protectors against radiation. XXXIII. Protective mechanisms of various compounds against skin injury induced by radiation].

    PubMed

    Sato, Y; Kumazawa, N; Suzuki, M; Wang, C M; Ohta, S; Shinoda, M

    1991-01-01

    The radiation protective mechanisms on skin injury induced by soft X-irradiation were investigated by use of various radiation protective agents such as sulfur compounds (MEA, MEG, thiourea), nucleic acid constitutional compounds (adenosine, inosine), antioxidative compounds (sesamol, ferulic acid, ascorbic acid), crude drugs (Rosae Fructus, Anemarrhenae Rhizoma, Trapae Fructus, Forsythiae Fructus, Aloe arborescens). Scavenge action of activated oxygen, inhibitory effect of lipid peroxidation, induction of antioxidative protein and protective effect against damage of deoxyribonucleic acid and superoxide dismutase by X-irradiation were evaluated as the radiation protective mechanisms, and relationship between these results and protective effect of skin injury induced by radiation was studied. PMID:1905349

  6. A mechanistic model for radiation-induced crystallization and amorphization in U 3Si

    Microsoft Academic Search

    J. Rest

    1995-01-01

    Of concern for the proposed Advanced Neutron Source and Research Reactors, which would use intermetallic fuels, are potential radiation-induced phenomena that could affect the physical and mechanical properties of intermetallic aluminum dispersion fuels. For this reason and because of observations of radiation-induced amorphization of U3Si during ion irradiation, the phenomenology of radiation-induced amorphization is assessed. A rate theory model is

  7. Connecting radiation-induced bystander effects and senescence to improve radiation response prediction.

    PubMed

    Poleszczuk, Jan; Krzywon, Aleksandra; Forys, Urszula; Widel, Maria

    2015-05-01

    For the last two decades radiation-induced bystander effects (RIBEs) have attracted significant attention due to their possible implications for radiotherapy. However, despite extensive research, the molecular pathways associated with RIBEs are still not completely known. In the current study we investigated the role of senescence in the bystander response. Irradiated (2, 4, 6 and 8 Gy) human colorectal carcinoma cells (HCT116) with p53(+/+) (wild-type) or p53(-/-) (knockout) gene were co-incubated with nonirradiated cells of the same type. Clonogenic and senescence assays were used for both irradiated and co-incubated bystander cell populations. We also performed additional measurements on the number of remaining cells after the whole co-incubation period. For radiation doses larger than 2 Gy we observed much larger fractions of senescent cells in p53-positive populations compared to their p53-negative counterparts (15.81% vs. 3.63% in the irradiated population; 2.89% vs. 1.05% in the bystander population; 8 Gy; P < 0.05). Statistically significant differences between cell lines in the clonogenic cell surviving fraction were observed for doses higher than 4 Gy (1.61% for p53(+/+) vs. 0.19% for p53(-/-) in irradiated population; 3.57% for +/+ vs. 50.39% for -/- in bystander population; 8 Gy; P < 0.05). Our main finding was that the number of senescent cells in the irradiated population correlated strongly with the clonogenic cell surviving fraction (R = -0.98, P < 0.001) and the number of senescent cells (R = 0.97, P < 0.001) in the bystander population. We also extended the standard linear-quadratic radiation response model by incorporating the influence of the signals released by the senescent cells, which accurately described the radiation response in the bystander population. Our findings suggest that radiation-induced senescence might be a key player in RIBE, i.e., the strength of RIBE depends on the amount of radiation-induced senescence. PMID:25844948

  8. Simulation of ion induced radiation damage in cells

    NASA Astrophysics Data System (ADS)

    Friedland, W.; Jacob, P.; Paretzke, H. G.; Ottolenghi, A.; Ballarini, F.; Dingfelder, M.

    The biophysical simulation code PARTRAC has been used in several studies of DNA damage induced by various radiation qualities including photons electrons protons alphas and ions heavier than alpha particles Ion-electron interaction cross sections are taken from isotachic protons scaled by Z eff 2 with the effective charge calculated according to the Barkas formula Recently ion type dependent angular distributions were introduced for intermediate secondary electron energies taking into account the different kinematic scaling of the constituents of the electron spectra Calculated stopping powers radial dose distributions and secondary electron spectra were found in good agreement with available experimental and theoretical results Radiation damage to DNA is determined in PARTRAC by superposition of the calculated track structures with a DNA target model taking into account direct effects from coincidences of ionisations and atoms within the DNA helix as well as indirect effects due to interactions of OH radicals produced in water surrounding the DNA For a simulation of radiation effects in human cells this target model comprises several genomic structure levels from the DNA double-helix up to chromosomes Calculated DNA damage due to irradiation of human fibroblast cells by ions of boron nitrogen and neon was compared to corresponding experimental data The calculated total yield of DSB per dose showed saturation behaviour with an RBE of about 2 whereas experimental data had a decreasing tendency with increasing LET to RBE values

  9. Proton-induced radiation damage in germanium detectors

    NASA Technical Reports Server (NTRS)

    Brueckner, J.; Koerfer, M.; Waenke, H.; Schroeder, A. N. F.; Filges, D.; Dragovitsch, P.; Englert, P. A. J.; Starr, R.; Trombka, J. I.

    1991-01-01

    High-purity germanium (HPGe) detectors will be used in future space missions for gamma-ray measurements and will be subject to interactions with energetic particles. To simulate this process, several large-volume n-type HPGe detectors were incrementally exposed to a particle fluence of up to 10 to the 8th protons/sq cm (proton energy: 1.5 GeV) at different operating temperatures (90 to 120 K) to induce radiation damage. Basic scientific and engineering data on detector performance were collected. During the incremental irradiation, the peak shape produced by the detectors showed a significant change from a Gaussian shape to a broad complex structure. After the irradiation, all detectors were thoroughly characterized by measuring many parameters. To remove the accumulated radiation damage, the detectors were stepwise-annealed at temperatures below 110 C, while kept in their specially designed cryostats. This study shows that n-type HPGe detectors can be used in charged-particle environments as high-energy resolution devices until a certain level of radiation damage is accumulated and that the damage can be removed at moderate annealing temperatures and the detector returned to operating condition.

  10. Radiation-Induced Prompt Photocurrents in Microelectronics: Physics

    SciTech Connect

    DODD, PAUL E.; VIZKELETHY, GYORGY; WALSH, DAVID S.; BULLER, DANIEL L.; DOYLE, BARNEY L.; BEEZHLD, WENDLAND

    2003-01-01

    The effects of photocurrents in nuclear weapons induced by proximal nuclear detonations are well known and remain a serious hostile environment threat for the US stockpile. This report describes the final results of an LDRD study of the physical phenomena underlying prompt photocurrents in microelectronic devices and circuits. The goals of this project were to obtain an improved understanding of these phenomena, and to incorporate improved models of photocurrent effects into simulation codes to assist designers in meeting hostile radiation requirements with minimum build and test cycles. We have also developed a new capability on the ion microbeam accelerator in Sandia's Ion Beam Materials Research Laboratory (the Transient Radiation Microscope, or TRM) to supply ionizing radiation in selected micro-regions of a device. The dose rates achieved in this new facility approach those possible with conventional large-scale dose-rate sources at Sandia such as HERMES III and Saturn. It is now possible to test the physics and models in device physics simulators such as Davinci in ways not previously possible. We found that the physical models in Davinci are well suited to calculating prompt photocurrents in microelectronic devices, and that the TRM can reproduce results from conventional large-scale dose-rate sources in devices where the charge-collection depth is less than the range of the ions used in the TRM.

  11. Radiation-induced defects in clay minerals: A review

    NASA Astrophysics Data System (ADS)

    Allard, Th.; Balan, E.; Calas, G.; Fourdrin, C.; Morichon, E.; Sorieul, S.

    2012-04-01

    Extensive information has been collected on radiation effects on clay minerals over the last 35 years, providing a wealth of information on environmental and geological processes. The fields of applications include the reconstruction of past radioelement migrations, the dating of clay minerals or the evolution of the physico-chemical properties under irradiation. The investigation of several clay minerals, namely kaolinite, dickite, montmorillonite, illite and sudoite, by Electron Paramagnetic Resonance Spectroscopy has shown the presence of defects produced by natural or artificial radiations. These defects consist mostly of electron holes located on oxygen atoms of the structure. The various radiation-induced defects are differentiated through their nature and their thermal stability. Most of them are associated with a ? orbital on a Si-O bond. The most abundant defect in clay minerals is oriented perpendicular to the silicate layer. Thermal annealing indicates this defect in kaolinite (A-center) to be stable over geological periods at ambient temperature. Besides, electron or heavy ion irradiation easily leads to an amorphization in smectites, depending on the type of interlayer cation. The amorphization dose exhibits a bell-shaped variation as a function of temperature, with a decreasing part that indicates the influence of thermal dehydroxylation. Two main applications of the knowledge of radiation-induced defects in clay minerals are derived: (i) The use of defects as tracers of past radioactivity. In geological systems where the age of the clay can be constrained, ancient migrations of radioelements can be reconstructed in natural analogues of high level nuclear waste repositories. When the dose rate may be assumed constant over time, the paleodose is used to date clay populations, an approach applied to fault gouges or laterites of the Amazon basin. (ii) The influence of irradiation over physico-chemical properties of clay minerals. An environmental application concerns the performance assessment of the engineered barrier of nuclear waste disposals. In case of a leakage of transuranic elements from the radioactive waste form, alpha recoil nuclei can amorphize smectite after periods of the order of 1000 years according to a worst case scenario, whereas amorphization from ionizing radiation is unlikely. As amorphization greatly enhances the dissolution kinetics of smectite, the sensitivity of the smectites must be taken into account in the prediction of the long term behavior of engineered barriers.

  12. Image-based modeling of radiation-induced foci

    NASA Astrophysics Data System (ADS)

    Costes, Sylvain; Cucinotta, Francis A.; Ponomarev, Artem; Barcellos-Hoff, Mary Helen; Chen, James; Chou, William; Gascard, Philippe

    Several proteins involved in the response to DNA double strand breaks (DSB) form microscopically visible nuclear domains, or foci, after exposure to ionizing radiation. Radiation-induced foci (RIF) are believed to be located where DNA damage occurs. To test this assumption, we used Monte Carlo simulations to predict the spatial distribution of DSB in human nuclei exposed to high or low-LET radiation. We then compared these predictions to the distribution patterns of three DNA damage sensing proteins, i.e. 53BP1, phosphorylated ATM and ?H2AX in human mammary epithelial. The probability to induce DSB can be derived from DNA fragment data measured experimentally by pulsed-field gel electrophoresis. We first used this probability in Monte Carlo simulations to predict DSB locations in synthetic nuclei geometrically described by a complete set of human chromosomes, taking into account microscope optics from real experiments. Simulations showed a very good agreement for high-LET, predicting 0.7 foci/µm along the path of a 1 GeV/amu Fe particle against measurement of 0.69 to 0.82 foci/µm for various RIF 5 min following exposure (LET 150 keV/µm). On the other hand, discrepancies were shown in foci frequency for low-LET, with measurements 20One drawback using a theoretical model for the nucleus is that it assumes a simplistic and static pattern for DNA densities. However DNA damage pattern is highly correlated to DNA density pattern (i.e. the more DNA, the more likely to have a break). Therefore, we generalized our Monte Carlo approach to real microscope images, assuming pixel intensity of DAPI in the nucleus was directly proportional to the amount of DNA in that pixel. With such approach we could predict DNA damage pattern in real images on a per nucleus basis. Since energy is randomly deposited along high-LET particle paths, RIF along these paths should also be randomly distributed. As expected, simulations produced DNA-weighted random (Poisson) distributions. In contrast, the distributions of RIF obtained as early as 5 min after exposure to high LET (1 GeV/amu Fe) were non-random. This deviation from the expected DNA-weighted random pattern was further characterized by "relative DNA image measurements". This novel imaging approach showed that RIF were located preferentially at the interface between high and low DNA density regions, and were more frequent than predicted in regions with lower DNA density. The same preferential nuclear location was also measured for RIF induced by 1 Gy of low-LET radiation. This deviation from random behavior was evident only 5 min after irradiation for phosphorylated ATM RIF, while ?H2AX and 53BP1 RIF showed pronounced deviations up to 30 min after exposure. These data suggest that RIF within a few minutes following exposure to radiation cluster into open regions of the nucleus (i.e. euchromatin). It is possible that DNA lesions are collected in these nuclear sub-domains for more efficient repair. If so, this would imply that DSB are actively transported within the nucleus, a phenomenon that has not yet been considered in modeling DNA misrepair following exposure to radiation. These results are thus critical for more accurate risk models of radiation and we are actively working on characterizing further RIF movement in human nuclei using live cell imaging.

  13. An amino acid mixture mitigates radiation-induced gastrointestinal toxicity.

    PubMed

    Yin, Liangjie; Vijaygopal, Pooja; Menon, Rejeesh; Vaught, Lauren A; Zhang, Mei; Zhang, Lurong; Okunieff, Paul; Vidyasagar, Sadasivan

    2014-06-01

    Electrolyte and nutrient absorption occur in villous epithelial cells. Radiation often results in reduced electrolyte and nutrient absorption, which leads to gastrointestinal toxicity. Therefore, the authors studied: (1) radiation-induced changes in glucose and amino acid absorption across ileal tissues and (2) the effect of amino acid mixtures on absorptive capacity. NIH Swiss mice were irradiated (0, 1, 3, 5, or 7 Gy) using a ¹³?Cs source at 0.9 Gy min?¹. Transepithelial short circuit current (I(sc)), dilution potential, and isotope flux determinations were made in Ussing chamber studies and correlated to plasma endotoxin and IL-1? levels. Amino acids that increased electrolyte absorption and improved mucosal barrier functions were used to create a mitigating amino acid mixture (MAAM). The MAAM was given to mice via gastric gavage; thereafter, body weight and survival were recorded. A significant decrease in basal and glucose-stimulated sodium absorption occurred after 0, 1, 3, 5, and 7 Gy irradiation. Ussing chamber studies showed that paracellular permeability increased following irradiation and that the addition of glucose resulted in a further increase in permeability. Following irradiation, certain amino acids manifested decreased absorption, whereas others were associated with increased absorption. Lysine, aspartic acid, glycine, isoleucine, threonine, tyrosine, valine, tryptophan, and serine decreased plasma endotoxins were selected for the MAAM. Mice treated with the MAAM showed increased electrolyte absorption and decreased paracellular permeability, IL-1? levels, and plasma endotoxin levels. Mice treated with MAAM also had increased weight gain and better survival following irradiation. The MAAM has immediate potential for use in mitigating radiation-induced acute gastrointestinal syndrome. PMID:24776907

  14. Interleukin12 suppresses ultraviolet radiation-induced apoptosis by inducing DNA repair

    Microsoft Academic Search

    Agatha Schwarz; Sonja Ständer; Mark Berneburg; Markus Böhm; Dagmar Kulms; Harry van Steeg; Karin Grosse-Heitmeyer; Jean Krutmann; Thomas Schwarz

    2001-01-01

    Induction of apoptosis of keratinocytes by ultraviolet (UV) radiation is a protective phenomenon relevant in limiting the survival of cells with irreparable DNA damage. Changes in UV-induced apoptosis may therefore have significant impact on photocarcinogenesis. We have found that the immunomodulatory cytokine IL-12 suppresses UV-mediated apoptosis of keratinocytes both in vitro and in vivo. IL-12 caused a remarkable reduction in

  15. Simultaneous broadband light trapping and fill factor enhancement in crystalline silicon solar cells induced by Ag nanoparticles and nanoshells.

    PubMed

    Fahim, Narges F; Jia, Baohua; Shi, Zhengrong; Gu, Min

    2012-09-10

    Crystalline silicon solar cells are predominant and occupying more than 89% of the global solar photovoltaic market. Despite the boom of the innovative solar technologies, few can provide a low-cost radical solution to dramatically boost the efficiency of crystalline silicon solar cells, which has reached plateau in the past ten years. Here, we present a novel strategy to simultaneously achieve dramatic enhancement in the short-circuit current and the fill factor through the integration of Ag plasmonic nanoparticles and nanoshells on the antireflection coating and the screen-printed fingers of monocrystalline silicon solar cells, respectively, by a single step and scalable modified electroless displacement method. As a consequence, up to 35.2% enhancement in the energy conversion efficiency has been achieved due to the plasmonic broadband light trapping and the significant reduction in the series resistance. More importantly, this method can further increase the efficiency of the best performing textured solar cells from 18.3% to 19.2%, producing the highest efficiency cells exceeding the state-of-the-art efficiency of the standard screen-printed solar cells. The dual functions of the Ag nanostructures, reported for the first time here, present a clear contrast to the previous works, where plasmonic nanostructures were integrated into solar cells to achieve the short-circuit current enhancement predominately. Our method offers a facile, cost-effective and scalable pathway for metallic nanostructures to be used to dramatically boost the overall efficiency of the optically thick crystalline silicon solar cells. PMID:23037536

  16. Dosimetric Analysis of Radiation-induced Gastric Bleeding

    SciTech Connect

    Feng, Mary, E-mail: maryfeng@umich.edu [Department of Radiation Oncology, University of Michigan School of Medicine, Ann Arbor, Michigan (United States)] [Department of Radiation Oncology, University of Michigan School of Medicine, Ann Arbor, Michigan (United States); Normolle, Daniel [Department of Biostatistics, University of Pittsburgh, Pittsburgh, Pennsylvania (United States)] [Department of Biostatistics, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); Pan, Charlie C. [Department of Radiation Oncology, University of Michigan School of Medicine, Ann Arbor, Michigan (United States)] [Department of Radiation Oncology, University of Michigan School of Medicine, Ann Arbor, Michigan (United States); Dawson, Laura A. [Department of Radiation Oncology, Princess Margaret Hospital, University of Toronto, Toronto, Ontario (Canada)] [Department of Radiation Oncology, Princess Margaret Hospital, University of Toronto, Toronto, Ontario (Canada); Amarnath, Sudha [Department of Radiation Oncology, University of Michigan School of Medicine, Ann Arbor, Michigan (United States)] [Department of Radiation Oncology, University of Michigan School of Medicine, Ann Arbor, Michigan (United States); Ensminger, William D. [Department of Internal Medicine, Division of Hematology Oncology, University of Michigan School of Medicine, Ann Arbor, Michigan (United States)] [Department of Internal Medicine, Division of Hematology Oncology, University of Michigan School of Medicine, Ann Arbor, Michigan (United States); Lawrence, Theodore S.; Ten Haken, Randall K. [Department of Radiation Oncology, University of Michigan School of Medicine, Ann Arbor, Michigan (United States)] [Department of Radiation Oncology, University of Michigan School of Medicine, Ann Arbor, Michigan (United States)

    2012-09-01

    Purpose: Radiation-induced gastric bleeding has been poorly understood. In this study, we described dosimetric predictors for gastric bleeding after fractionated radiation therapy. Methods and Materials: The records of 139 sequential patients treated with 3-dimensional conformal radiation therapy (3D-CRT) for intrahepatic malignancies were reviewed. Median follow-up was 7.4 months. The parameters of a Lyman normal tissue complication probability (NTCP) model for the occurrence of {>=}grade 3 gastric bleed, adjusted for cirrhosis, were fitted to the data. The principle of maximum likelihood was used to estimate parameters for NTCP models. Results: Sixteen of 116 evaluable patients (14%) developed gastric bleeds at a median time of 4.0 months (mean, 6.5 months; range, 2.1-28.3 months) following completion of RT. The median and mean maximum doses to the stomach were 61 and 63 Gy (range, 46-86 Gy), respectively, after biocorrection of each part of the 3D dose distributions to equivalent 2-Gy daily fractions. The Lyman NTCP model with parameters adjusted for cirrhosis predicted gastric bleed. Best-fit Lyman NTCP model parameters were n=0.10 and m=0.21 and with TD{sub 50} (normal) = 56 Gy and TD{sub 50} (cirrhosis) = 22 Gy. The low n value is consistent with the importance of maximum dose; a lower TD{sub 50} value for the cirrhosis patients points out their greater sensitivity. Conclusions: This study demonstrates that the Lyman NTCP model has utility for predicting gastric bleeding and that the presence of cirrhosis greatly increases this risk. These findings should facilitate the design of future clinical trials involving high-dose upper abdominal radiation.

  17. Surface-energy induced formation of single crystalline bismuth nanowires over vanadium thin film at room temperature.

    PubMed

    Liu, Mingzhao; Tao, Jing; Nam, Chang-Yong; Kisslinger, Kim; Zhang, Lihua; Su, Dong

    2014-10-01

    We report high-yield room-temperature growth of vertical single-crystalline bismuth nanowire array by vacuum thermal evaporation of bismuth over a choice of arbitrary substrate coated with a thin interlayer of nanoporous vanadium. The nanowire growth is the result of spontaneous and continuous expulsion of nanometer-sized bismuth domains from the vanadium pores, driven by their excessive surface energy that suppresses the melting point of bismuth close to room temperature. The simplicity of the technique opens a new avenue for the growth of nanowire arrays of a variety of materials. PMID:25244508

  18. Growth hormone and insulin-like growth factor I protect intestinal cells from radiation induced apoptosis

    Microsoft Academic Search

    Panagiotis G Mylonas; Panagiota T Matsouka; Eleni V Papandoniou; Constantine Vagianos; Fotis Kalfarentzos; Theodore K Alexandrides

    2000-01-01

    We studied whether programmed cell death (or apoptosis) is the predominant mechanism in radiation-induced cell damage to rat intestinal mucosa and investigated the mechanism of the protective effect of GH and IGF-I in the same model. Male albino Wistar rats were divided into four groups: controls, radiation, radiation plus GH and radiation plus IGF-I. Radiation was administered on the first

  19. Radiation Induced Incorporation of CO in Pure and Aqueous Methanol

    NASA Astrophysics Data System (ADS)

    Jung, Hak-Jin; Getoff, Nikola; Lorbeer, Eberhard

    1994-05-01

    Pure and aqueous methanol were used for radiation induced incorporation of CO at elevated pressure (up to 15 bar). The initial yields (Gi) of the main products in pure methanol under 15 bar CO and 1 bar N2O were found to be: Gi(formaldehyde) = 3.80 and Gi(glycolic aldehyde) = 2.0. For aqueous (10-2 mol · dm-3) methanol under 15 bar CO (dose: 0.557 kGy, pH = 2): the yields were G(formaldehyde) = 5.44, G(glycolic aldehyde) = 4.0 and G(oxalic acid) = 7.7. At pH = 7 the yields were essentially lower, namely: G(formaldehyde) = 3.2, G(glycolic aldehyde) = 2.0, G(formate) = 3.8 and G(oxalate) = 5.0. Probable reaction-mechanisms for the product formation are discussed.

  20. Characterization of gamma radiation inducible thioredoxin h from Spirogyra varians.

    PubMed

    Yoon, Minchul; Yang, Ho-Yeon; Lee, Seung-Sik; Kim, Dong-Ho; Kim, Gwang-Hoon; Choi, Jong-il

    2013-08-15

    In this study, thioredoxin h (Trxh) was isolated and characterized from the fresh water green alga Spirogyra varians, which was one amongst the pool of proteins induced upon gamma radiation treatment. cDNA clones encoding S. varians thioredoxin h were isolated from a pre-constructed S. varians cDNA library. Trxh had a molecular mass of 13.5kDa and contained the canonical WCGPC active site. Recombinant Trxh showed the disulfide reduction activity, and exhibited insulin reduction activity. Also, Trxh had higher 5,5'-dithiobis(2-nitrobenzoic acid) reduction activity with Arabidopsis thioredoxin reductase (TR) than with Escherichia coli TR. Specific expression of the Trxh gene was further analyzed at mRNA and protein levels and was found to increase by gamma irradiation upto the absorbed dose of 3kGy, suggesting that Trxh may have potential functions in protection of biomolecules from gamma irradiation. PMID:23830452

  1. Aviation-induced cirrus and radiation changes at diurnal timescales

    NASA Astrophysics Data System (ADS)

    Schumann, Ulrich; Graf, Kaspar

    2013-03-01

    Abstract The <span class="hlt">radiative</span> forcing from aviation-<span class="hlt">induced</span> cirrus is derived from observations and models. The annual mean diurnal cycle of airtraffic in the North Atlantic region exhibits two peaks in early morning and afternoon with different peak times in the western and eastern parts of the North Atlantic region. The same "aviation fingerprint" is found in 8 years (2004-2011) of Meteosat observations of cirrus cover and OLR. The observations are related to airtraffic data with linear response models assuming the background atmosphere without aviation to be similar to that observed in the South Atlantic. The change in OLR is interpreted as aviation-<span class="hlt">induced</span> longwave <span class="hlt">radiative</span> forcing (LW RF). The data analysis suggests an LW RF of about 600-900 mW m-2 regionally. A detailed contrail cirrus model for given global meteorology and airtraffic in 2006 gives similar results. The global RF is estimated from the ratio of global and regional RF as derived from three models. The extrapolation implies about 100-160 mW m-2 global LW RF. The models show large differences in the shortwave/longwave RF-magnitude ratio. One model computes a ratio of 0.6, implying an estimate of global net RF of about 50 mW m-2 (40-80 mW m-2). Other models suggest smaller ratios, with less cooling during day, which would imply considerably larger net effects. The sensitivity of the results to the accuracy of the observations, traffic data, and models and the estimated background is discussed.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PMC&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3936513"><span id="translatedtitle">Hematopoietic Stem Cell Injury <span class="hlt">Induced</span> by Ionizing <span class="hlt">Radiation</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Shao, Lijian; Luo, Yi</p> <p>2014-01-01</p> <p>Abstract Significance: Exposure to ionizing <span class="hlt">radiation</span> (IR) as the result of nuclear accidents or terrorist attacks is a significant threat and a major medical concern. Hematopoietic stem cell (HSC) injury is the primary cause of death after accidental or intentional exposure to a moderate or high dose of IR. Protecting HSCs from IR should be a primary goal in the development of novel medical countermeasures against <span class="hlt">radiation</span>. Recent Advances: Significant progress has been made in our understanding of the mechanisms by which IR causes HSC damage. The mechanisms include (i) induction of HSC apoptosis via the p53-Puma pathway; (ii) promotion of HSC differentiation via the activation of the G-CSF/Stat3/BATF-dependent differentiation checkpoint; (iii) induction of HSC senescence via the ROS-p38 pathway; and (iv) damage to the HSC niche. Critical Issues: Induction of apoptosis in HSCs and hematopoietic progenitor cells is primarily responsible for IR-<span class="hlt">induced</span> acute bone marrow (BM) injury. Long-term BM suppression caused by IR is mainly attributable to the induction of HSC senescence. However, the promotion of HSC differentiation and damage to the HSC niche can contribute to both the acute and long-term effects of IR on the hematopoietic system. Future Directions: In this review, we have summarized a number of recent findings that provide new insights into the mechanisms whereby IR damages HSCs. These findings will provide new opportunities for developing a mechanism-based strategy to prevent and/or mitigate IR-<span class="hlt">induced</span> BM suppression. Antioxid. Redox Signal. 20, 1447–1462. PMID:24124731</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASA-TRS&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20040088238&hterms=BYSTANDER&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DBYSTANDER"><span id="translatedtitle">Bystander effects in <span class="hlt">radiation-induced</span> genomic instability</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Morgan, William F.; Hartmann, Andreas; Limoli, Charles L.; Nagar, Shruti; Ponnaiya, Brian</p> <p>2002-01-01</p> <p>Exposure of GM10115 hamster-human hybrid cells to X-rays can result in the induction of chromosomal instability in the progeny of surviving cells. This instability manifests as the dynamic production of novel sub-populations of cells with unique cytogenetic rearrangements involving the "marker" human chromosome. We have used the comet assay to investigate whether there was an elevated level of endogenous DNA breaks in chromosomally unstable clones that could provide a source for the chromosomal rearrangements and thus account for the persistent instability observed. Our results indicate no significant difference in comet tail measurement between non-irradiated and <span class="hlt">radiation-induced</span> chromosomally unstable clones. Using two-color fluorescence in situ hybridization we also investigated whether recombinational events involving the interstitial telomere repeat-like sequences in GM10115 cells were involved at frequencies higher than random processes would otherwise predict. Nine of 11 clones demonstrated a significantly higher than expected involvement of these interstitial telomere repeat-like sequences at the recombination junction between the human and hamster chromosomes. Since elevated levels of endogenous breaks were not detected in unstable clones we propose that epigenetic or bystander effects (BSEs) lead to the activation of recombinational pathways that perpetuate the unstable phenotype. Specifically, we expand upon the hypothesis that <span class="hlt">radiation</span> <span class="hlt">induces</span> conditions and/or factors that stimulate the production of reactive oxygen species (ROS). These reactive intermediates then contribute to a chronic pro-oxidant environment that cycles over multiple generations, promoting chromosomal recombination and other phenotypes associated with genomic instability.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2012RaPC...81..840Y"><span id="translatedtitle"><span class="hlt">Radiation</span> <span class="hlt">induced</span> copolymerization reactivity of different allyl monomers with styrene</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yildirim, Yeliz; Balcan, Mehmet</p> <p>2012-07-01</p> <p><span class="hlt">Radiation</span> <span class="hlt">induced</span> copolymerizations of electron donating such as allyl phenol (AP) and electron withdrawing such as allyl isothiocyanate (AITC) monomers with styrene (Sty) as a comonomer were studied in order to correlate the electronic behavior with copolymerization yield and molecular weight. The allyl monomers and comonomer were mixed in the same mol ratios under Ar atmosphere and copolymerized by using gamma <span class="hlt">radiation</span> in various absorbed doses (55, 110, 165 kGy) obtained from a Co-60 source. Poly(AP-co-Sty), and poly(AITC-co-Sty) could have been prepared at all of the absorbed doses. The maximum copolymerization yields were calculated as a 16.35 and 6.52 percent for poly(AP-co-Sty) and poly(AITC-co-Sty), respectively. The molecular weights of poly(AP-co-Sty) copolymers are found to be higher in comparison to those of poly(AITC-co-Sty). Both results indicate that, under the same irradiation conditions, AP is more reactive on styrene than AITC is. Thus, the monomers having electron withdrawing (EW) substituents attached to allyl group may result in better copolymerization yield and molecular weight than those with electron donating (ED) substituents. Thermal stabilities of the poly(AP-co-Sty) copolymers are also higher than those of poly(AITC-co-Sty).</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PMC&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4259957"><span id="translatedtitle"><span class="hlt">Radiation-induced</span> sarcomas of the head and neck</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Thiagarajan, Anuradha; Iyer, N Gopalakrishna</p> <p>2014-01-01</p> <p>With improved outcomes associated with radiotherapy, <span class="hlt">radiation-induced</span> sarcomas (RIS) are increasingly seen in long-term survivors of head and neck cancers, with an estimated risk of up to 0.3%. They exhibit no subsite predilection within the head and neck and can arise in any irradiated tissue of mesenchymal origin. Common histologic subtypes of RIS parallel their de novo counterparts and include osteosarcoma, chondrosarcoma, malignant fibrous histiocytoma/sarcoma nitricoxide synthase, and fibrosarcoma. While imaging features of RIS are not pathognomonic, large size, extensive local invasion with bony destruction, marked enhancement within a prior radiotherapy field, and an appropriate latency period are suggestive of a diagnosis of RIS. RIS development may be influenced by factors such as <span class="hlt">radiation</span> dose, age at initial exposure, exposure to chemotherapeutic agents and genetic tendency. Precise pathogenetic mechanisms of RIS are poorly understood and both directly mutagenizing effects of radiotherapy as well as changes in microenvironments are thought to play a role. Management of RIS is challenging, entailing surgery in irradiated tissue and a limited scope for further radiotherapy and chemotherapy. RIS is associated with significantly poorer outcomes than stage-matched sarcomas that arise independent of irradiation and surgical resection with clear margins seems to offer the best chance for cure. PMID:25493233</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2014ApPhL.104w3109C"><span id="translatedtitle"><span class="hlt">Radiation</span> <span class="hlt">induced</span> effects on mechanical properties of nanoporous gold foams</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Caro, M.; Mook, W. M.; Fu, E. G.; Wang, Y. Q.; Sheehan, C.; Martinez, E.; Baldwin, J. K.; Caro, A.</p> <p>2014-06-01</p> <p>It has recently been shown that due to a high surface-to-volume ratio, nanoporous materials display <span class="hlt">radiation</span> tolerance. The abundance of surfaces, which are perfect sinks for defects, and the relation between ligament size, defect diffusion, and time combine to define a window of <span class="hlt">radiation</span> resistance [Fu et al., Appl. Phys. Lett. 101, 191607 (2012)]. Outside this window, the dominant defect created by irradiation in Au nanofoams are stacking fault tetrahedra (SFT). Molecular dynamics computer simulations of nanopillars, taken as the elemental constituent of foams, predict that SFTs act as dislocation sources <span class="hlt">inducing</span> softening, in contrast to the usual behavior in bulk materials, where defects are obstacles to dislocation motion, producing hardening. In this work we test that prediction and answer the question whether irradiation actually hardens or softens a nanofam. Ne ion irradiations of gold nanofoams were performed at room temperature for a total dose up to 4 dpa, and their mechanical behavior was measured by nanoindentation. We find that hardness increases after irradiation, a result that we analyze in terms of the role of SFTs on the deformation mode of foams.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/22300035"><span id="translatedtitle"><span class="hlt">Radiation</span> <span class="hlt">induced</span> effects on mechanical properties of nanoporous gold foams</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Caro, M., E-mail: magda@lanl.gov, E-mail: efu@pku.edu.cn; Fu, E. G., E-mail: magda@lanl.gov, E-mail: efu@pku.edu.cn; Wang, Y. Q.; Martinez, E.; Caro, A. [Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Mook, W. M.; Sheehan, C.; Baldwin, J. K. [Center for Integrated Nanotechnology, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)</p> <p>2014-06-09</p> <p>It has recently been shown that due to a high surface-to-volume ratio, nanoporous materials display <span class="hlt">radiation</span> tolerance. The abundance of surfaces, which are perfect sinks for defects, and the relation between ligament size, defect diffusion, and time combine to define a window of <span class="hlt">radiation</span> resistance [Fu et al., Appl. Phys. Lett. 101, 191607 (2012)]. Outside this window, the dominant defect created by irradiation in Au nanofoams are stacking fault tetrahedra (SFT). Molecular dynamics computer simulations of nanopillars, taken as the elemental constituent of foams, predict that SFTs act as dislocation sources <span class="hlt">inducing</span> softening, in contrast to the usual behavior in bulk materials, where defects are obstacles to dislocation motion, producing hardening. In this work we test that prediction and answer the question whether irradiation actually hardens or softens a nanofam. Ne ion irradiations of gold nanofoams were performed at room temperature for a total dose up to 4 dpa, and their mechanical behavior was measured by nanoindentation. We find that hardness increases after irradiation, a result that we analyze in terms of the role of SFTs on the deformation mode of foams.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/5457416"><span id="translatedtitle"><span class="hlt">Radiation-induced</span> tumors in transplanted ovaries. [Mice</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Covelli, V.; Di Majo, V.; Bassani, B.; Metalli, P.; Silini, G.</p> <p>1982-04-01</p> <p>A comparison was made of tumor induction in the ovaries of whole-body-irradiation mice (250-kV X rays, doses of 0.25-4.00 Gy) or in ovaries irradiated in vivo and then transplanted intramuscularly into castrated syngeneic hosts. The form of the dose-induction relationships was similar in the two cases, showing a steeply rising branch at doses up to 0.75 Gy followed by a maximum and an elevated plateau up to 4.00 Gy. A higher incidence of tumors in transplanted organs was apparent for doses up to the maximum, which was attributed to castration-<span class="hlt">induced</span> hormonal imbalance. Specific death rate analysis of mice dying with ovarian tumors showed that in this system <span class="hlt">radiation</span> acts essentially by decreasing tumor latency. Ovarian tumors were classified in various histological types and their development in time was followed by serial sacrifice. Separate analysis of death rate of animals carrying different tumor classes allowed further resolution of the various components of the tumor induction phenomenon. It was thus possible to show that the overall death rate analysis masks a true effect of induction of granulosa cell tumors in whole-body-irradiation animals. The transplantation technique offers little advantage for the study of <span class="hlt">radiation</span> induction of ovarian tumor.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PMC&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3354559"><span id="translatedtitle">Are Epigenetic Mechanisms Involved in <span class="hlt">Radiation-Induced</span> Bystander Effects?</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Mothersill, Carmel; Seymour, Colin</p> <p>2012-01-01</p> <p>The “non-targeted effects” of ionizing <span class="hlt">radiation</span> including bystander effects and genomic instability are unique in that no classic mutagenic event occurs in the cell showing the effect. In the case of bystander effects, cells which were not in the field affected by the <span class="hlt">radiation</span> show high levels of mutations, chromosome aberrations, and membrane signaling changes leading to what is termed “horizontal transmission” of mutations and information which may be damaging while in the case of genomic instability, generations of cells derived from an irradiated progenitor appear normal but then lethal and non-lethal mutations appear in distant progeny. This is known as “vertical transmission.” In both situations high yields of non-clonal mutations leading to distant occurrence of mutation events both in space and time. This precludes a mutator phenotype or other conventional explanation and appears to indicate a generalized form of stress-<span class="hlt">induced</span> mutagenesis which is well documented in bacteria. This review will discuss the phenomenology of what we term “non-targeted effects,” and will consider to what extent they challenge conventional ideas in genetics and epigenetics. PMID:22629281</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PMC&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2557320"><span id="translatedtitle">Interference detection in implantable defibrillators <span class="hlt">induced</span> by therapeutic <span class="hlt">radiation</span> therapy</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Uiterwaal, G.J.; Springorum, B.G.F.; Scheepers, E.; de Ruiter, G.S.; Hurkmans, C.W.</p> <p>2006-01-01</p> <p>Background Electromagnetic fields and ionising <span class="hlt">radiation</span> during radiotherapy can influence the functioning of ICDs. Guidelines for radiotherapy treatment were published in 1994, but only based on experience with pacemakers. Data on the influence of radiotherapy on ICDs is limited. Objectives We determined the risk to ICDs of interference detection <span class="hlt">induced</span> by radiotherapy. Methods In our study we irradiated 11 ICDs. The irradiation was performed with a 6 megavolt photon beam. In each individual device test, a total of 20 Gray was delivered in a fractionated fashion. During each irradiation the output stimulation rate was monitored and electrogram storage was activated. In case of interference the test was repeated with the ICD outside and the lead(s) inside and outside the irradiation field. Results With the ICD inside the irradiation field, interference detection was observed in all ICDs. This caused pacing inhibition or rapid ventricular pacing. Ventricular tachycardia (VT) or ventricular fibrillation (VF) detection occurred, which would have caused tachycardia-terminating therapy. If the ICD was placed outside the irradiation field, no interference was observed. Conclusion Interference by ionising <span class="hlt">radiation</span> on the ICDs is demonstrated both on bradycardia and tachycardia therapy. This can have consequences for patients. Recommendations for radiotherapy are presented in this article. ImagesFigure 1Figure 5 PMID:25696559</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/1983PCM.....9..173K"><span id="translatedtitle">Heterogeneous shock-<span class="hlt">induced</span> thermal <span class="hlt">radiation</span> in minerals</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kondo, Ken-Ichi; Ahrens, Thomas J.</p> <p>1983-03-01</p> <p>A 500 channel optical imaging intensifying and spectral digital recording system is used to record the shock-<span class="hlt">induced</span> <span class="hlt">radiation</span> emitted from 406 to 821 nm from transparent minerals during the time interval that a shock wave propagates through the sample. Initial results obtained for single crystals of gypsum, calcite and halite in the 30 to 40 GPa (300 to 400 kbar) pressure range demonstrate greybody emission spectra corresponding to temperatures in the 3,000 to 4,000 K range and emissivities ranging from 0.003 to 0.02. In the case of gypsum and calcite, distinctive line spectra, are superimposed on the thermal <span class="hlt">radiation</span>. The observed color temperatures are a factor of 2 to 10 greater than the Hugoniot temperature, calculable on the basis of continuum thermodynamics and equation of state models for the shock states achieved in the three minerals. These observed high temperatures are believed to be real. We conclude that we are detecting a large number of closed spaced high temperature shear-band regions immediately behind the shock front. A shear instability model, such as proposed independently by Grady (1977, 1980), Ananin et al. (1974), and Horie (1980), in which small zones of highly deforming and melted material are produced which are the source of the detected thermal <span class="hlt">radiation</span> and have a fractional effective area approximately numerically equal to the measured emissivity, can be used to predict an effective emissivity of 0.0065 directly behind the shock front. If shear band instability arises from viscous flow processes, Grady's model and mineral thermal properties yield for the shocked mineral viscosities values in the range of 109 to 1015 P immediately behind the shock front.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2015PhyC..508...25Z"><span id="translatedtitle"><span class="hlt">Crystalline</span> phase transition information <span class="hlt">induced</span> by high temperature susceptibility transformations in bulk PMP-YBCO superconductor growth in-situ</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, C. P.; Chaud, X.; Beaugnon, E.; Zhou, L.</p> <p>2015-01-01</p> <p>The dynamic susceptibility transformations of bulk HTSC PMP-YBCO growth have been investigated from 200 °C up to 1060 °C by the Faraday Balance in-situ. It revealed that the <span class="hlt">crystalline</span> phase transitions of bulk PMP-YBCO growth in process. A new discovery of Y123 phase pre-formed then melted in heating stage has been found. It also discovered that Y123 crystal solidification started at 1004 °C in cooling stage. Before Y123 solidification the liquid phase CuO change to Cu2O reciprocally as well as the copper ion valence changed between divalent Cu2+ and trivalent Cu1+ each other. It was essential to keep quantities of CuO phase instead of the Cu2O for Y123 crystal solidification.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/26266240"><span id="translatedtitle">Mechanism of <span class="hlt">radiation-induced</span> degradation of poly(methyl methacrylate) — temperature effect</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Tsuneki Ichikawa</p> <p>1995-01-01</p> <p>ESR and gel permeation chromatographic measurements of poly(methyl methacrylate) ?-irradiated between 77 and 300 K have been carried out to elucidate the mechanism of <span class="hlt">radiation-induced</span> degradation of the polymer. It is revealed that the scission of the main chain does not take place immediately after the absorption of <span class="hlt">radiation</span> energy but is <span class="hlt">induced</span> by the intramolecular radical conversion of the</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/29243910"><span id="translatedtitle">Early hyperbaric oxygen therapy improves outcome for <span class="hlt">radiation-induced</span> hemorrhagic cystitis</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Kian Tai Chong; Neil B. Hampson; John M. Corman</p> <p>2005-01-01</p> <p>ObjectivesTo assess the clinical factors that affect the efficacy of hyperbaric oxygen (HBO2) therapy in treating <span class="hlt">radiation-induced</span> hemorrhagic cystitis. HBO2 therapy is an effective treatment for <span class="hlt">radiation-induced</span> hemorrhagic cystitis, with reported response rates ranging from 76% to 100%.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/60325809"><span id="translatedtitle">The response of kidney to ionizing <span class="hlt">radiation</span> combined with hyperthermia <span class="hlt">induced</span> by ultrasound</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>D. G. Baker; H. T. Sager; D. Elkon; W. Constable; L. Rinehart; M. Wills; J. Savory; D. Lacher</p> <p>1982-01-01</p> <p>Mouse kidneys were made hyperthermic (42.5 degrees C for 30 min) one hour before, during, or one hour after local irradiation to determine the effect of hyperthermia on <span class="hlt">radiation</span> damage. An ultrasound beam was used to <span class="hlt">induce</span> hyperthermia. The urinary concentrations of total protein and albumin were used as criteria of kidney injury. Hyperthermia alone did not <span class="hlt">induce</span> proteinuria. <span class="hlt">Radiation</span></p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/22149580"><span id="translatedtitle">Hyperbaric Oxygen Therapy for <span class="hlt">Radiation-Induced</span> Cystitis and Proctitis</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Oliai, Caspian; Fisher, Brandon; Jani, Ashish; Wong, Michael; Poli, Jaganmohan; Brady, Luther W. [Department of Radiation Oncology, Drexel University College of Medicine, Philadelphia, Pennsylvania (United States)] [Department of Radiation Oncology, Drexel University College of Medicine, Philadelphia, Pennsylvania (United States); Komarnicky, Lydia T., E-mail: lydia.komarnicky-kocher@drexelmed.edu [Department of Radiation Oncology, Drexel University College of Medicine, Philadelphia, Pennsylvania (United States)</p> <p>2012-11-01</p> <p>Purpose: To provide a retrospective analysis of the efficacy of hyperbaric oxygen therapy (HBOT) for treating hemorrhagic cystitis (HC) and proctitis secondary to pelvic- and prostate-only radiotherapy. Methods and Materials: Nineteen patients were treated with HBOT for <span class="hlt">radiation-induced</span> HC and proctitis. The median age at treatment was 66 years (range, 15-84 years). The range of external-beam <span class="hlt">radiation</span> delivered was 50.0-75.6 Gy. Bleeding must have been refractory to other therapies. Patients received 100% oxygen at 2.0 atmospheres absolute pressure for 90-120 min per treatment in a monoplace chamber. Symptoms were retrospectively scored according to the Late Effects of Normal Tissues-Subjective, Objective, Management, Analytic (LENT-SOMA) scale to evaluate short-term efficacy. Recurrence of hematuria/hematochezia was used to assess long-term efficacy. Results: Four of the 19 patients were lost to follow-up. Fifteen patients were evaluated and received a mean of 29.8 dives: 11 developed HC and 4 proctitis. All patients experienced a reduction in their LENT-SOMA score. After completion of HBOT, the mean LENT-SOMA score was reduced from 0.78 to 0.20 in patients with HC and from 0.66 to 0.26 in patients with proctitis. Median follow-up was 39 months (range, 7-70 months). No cases of hematuria were refractory to HBOT. Complete resolution of hematuria was seen in 81% (n = 9) and partial response in 18% (n = 2). Recurrence of hematuria occurred in 36% (n = 4) after a median of 10 months. Complete resolution of hematochezia was seen in 50% (n = 2), partial response in 25% (n = 1), and refractory bleeding in 25% (n = 1). Conclusions: Hyperbaric oxygen therapy is appropriate for <span class="hlt">radiation-induced</span> HC once less time-consuming therapies have failed to resolve the bleeding. In these conditions, HBOT is efficacious in the short and long term, with minimal side effects.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/20706262"><span id="translatedtitle"><span class="hlt">Radiation-induced</span> osteosarcomas in the pediatric population</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Koshy, Matthew [Department of Radiology, Division of Radiation Oncology, Baylor College of Medicine, Methodist Hospital, and Texas Children's Hospital, Houston, TX (United States); Paulino, Arnold C. [Department of Radiology, Division of Radiation Oncology, Baylor College of Medicine, Methodist Hospital, and Texas Children's Hospital, Houston, TX (United States)]. E-mail: apaulino@tmh.tmc.edu; Mai, Wei Y. [Department of Radiology, Division of Radiation Oncology, Baylor College of Medicine, Methodist Hospital, and Texas Children's Hospital, Houston, TX (United States); Teh, Bin S. [Department of Radiology, Division of Radiation Oncology, Baylor College of Medicine, Methodist Hospital, and Texas Children's Hospital, Houston, TX (United States)</p> <p>2005-11-15</p> <p>Purpose: <span class="hlt">Radiation-induced</span> osteosarcomas (R-OS) have historically been high-grade, locally invasive tumors with a poor prognosis. The purpose of this study was to perform a comprehensive literature review and analysis of reported cases dealing with R-OS in the pediatric population to identify the characteristics, prognostic factors, optimal treatment modalities, and overall survival of these patients. Methods and Materials: A MEDLINE/PubMed search of articles written in the English language dealing with OSs occurring after radiotherapy (RT) in the pediatric population yielded 30 studies from 1981 to 2004. Eligibility criteria included patients <21 years of age at the diagnosis of the primary cancer, cases satisfying the modified Cahan criteria, and information on treatment outcome. Factors analyzed included the type of primary cancer treated with RT, the <span class="hlt">radiation</span> dose and beam energy, the latency period between RT and the development of R-OS, and the treatment, follow-up, and final outcome of R-OS. Results: The series included 109 patients with a median age at the diagnosis of primary cancer of 6 years (range, 0.08-21 years). The most common tumors treated with RT were Ewing's sarcoma (23.9%), rhabdomyosarcoma (17.4%), retinoblastoma (12.8%), Hodgkin's disease (9.2%), brain tumor (8.3%), and Wilms' tumor (6.4%). The median <span class="hlt">radiation</span> dose was 47 Gy (range, 15-145 Gy). The median latency period from RT to the development of R-OS was 100 months (range, 36-636 months). The median follow-up after diagnosis of R-OS was 18 months (1-172 months). The 3- and 5-year cause-specific survival rate was 43.6% and 42.2%, respectively, and the 3- and 5-year overall survival rate was 41.7% and 40.2%, respectively. Variables, including age at RT, primary site, type of tumor treated with RT, total <span class="hlt">radiation</span> dose, and latency period did not have a significant effect on survival. The 5-year cause-specific and overall survival rate for patients who received treatment for R-OS involving chemotherapy alone, surgery alone, and surgery plus chemotherapy was 17.3% and 17.3%, 56.6% and 50.3%, and 71.0% and 68.3%, respectively (p < 0.0001, log-rank test). Conclusion: The type of treatment for R-OS was the most significant factor for cause-specific and overall survival. Patients who develop R-OS should be aggressively treated, because the outcome is not as dismal as once thought.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PUBMED&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/11295210"><span id="translatedtitle"><span class="hlt">Radiation-induced</span> granulocyte transmigration predicts development of delayed structural changes in rat intestine.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Richter, K K; Wang, J; Fagerhol, M K; Hauer-Jensen, M</p> <p>2001-04-01</p> <p>We examined whether early <span class="hlt">radiation-induced</span> granulocyte transmigration (assessed by the fecal transferrin excretion ELISA assay) predicts subsequent development of (consequential) chronic <span class="hlt">radiation</span> enteropathy. After accounting for the effect of <span class="hlt">radiation</span> dose, transferrin excretion remained an independent predictor of overall tissue injury, intestinal fibrosis, and mucosal ulcers, but not TGF-beta immunoreactivity. PMID:11295210</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/1591266"><span id="translatedtitle">Detection of environmental ultraviolet <span class="hlt">radiation</span> by the <span class="hlt">induced</span> electroluminescence in a ceramic detector</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Ching-Shen Su; Li-Chuing Wei</p> <p>1996-01-01</p> <p>Environmental ultraviolet (UV) <span class="hlt">radiation</span> can be detected passively by a ceramic sensor by measuring the <span class="hlt">radiation-induced</span> electroluminescence (EL). The phenomenon that metal-oxide ceramic material doped with certain impurities can emit photons under high electric fields after irradiation by UV has been observed in our laboratory. This phenomenon of EL only exists after the sensor has been irradiated by UV <span class="hlt">radiation</span>.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://radhome.gsfc.nasa.gov/radhome/papers/tns07_chen.pdf"><span id="translatedtitle">Mechanisms of Enhanced <span class="hlt">Radiation-Induced</span> Degradation Due to Excess Molecular Hydrogen in Bipolar Oxides</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>X. J. Chen; H. J. Barnaby; B. Vermeire; K. Holbert; D. Wright; R. L. Pease; G. Dunham; D.G. Platteter; J. Seiler; S. McClure; P. Adell</p> <p>2007-01-01</p> <p>Bipolar junction test structures packaged in hermetically sealed packages with excess molecular hydrogen (H2) showed enhanced degradation after <span class="hlt">radiation</span> exposure. Using chemical kinetics, we propose a model that quantitatively establishes the relationship between excess H2 and <span class="hlt">radiation-induced</span> interface trap formation. Using environments with different molecular hydrogen concentrations, <span class="hlt">radiation</span> experiments were performed and the experimental data showed excellent agreement with the</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2013RaPC...84..185T"><span id="translatedtitle">On the mechanisms of the <span class="hlt">radiation-induced</span> degradation of cellulosic substances</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tissot, Chanel; Grdanovska, Slavica; Barkatt, Aaron; Silverman, Joseph; Al-Sheikhly, Mohamad</p> <p>2013-03-01</p> <p>Much interest has been generated in utilizing ionizing <span class="hlt">radiation</span> for the production of bio-fuels from cellulosic plant materials. It is well known that exposure of cellulose to ionizing <span class="hlt">radiation</span> causes significant breakdown of the polysaccharide. <span class="hlt">Radiation-induced</span> degradation of cellulose may reduce or replace ecologically hazardous chemical steps in addition to reducing the number of processing stages and decreasing energy consumption.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/6847782"><span id="translatedtitle">Colitis cystica profunda occurring in a <span class="hlt">radiation-induced</span> colonic stricture</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Gardiner, G.W.; McAuliffe, N.; Murray, D.</p> <p>1984-03-01</p> <p>Localized colitis cystica profunda developed in a fibrotic <span class="hlt">radiation-induced</span> colonic stricture 17 years after pelvic <span class="hlt">radiation</span> for squamous carcinoma of cervix. This uncommon pathologic entity must be distinguished from invasive adenocarcinoma of colon, and colonic <span class="hlt">radiation</span> injury should be included with other conditions associated with colitis cystica profunda.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://www.columbia.edu/~djb3/papers/extrapolating.pdf"><span id="translatedtitle">EXTRAPOLATING <span class="hlt">RADIATION-INDUCED</span> CANCER RISKS FROM LOW DOSES TO VERY LOW DOSES</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Brenner, David Jonathan</p> <p></p> <p>Paper EXTRAPOLATING <span class="hlt">RADIATION-INDUCED</span> CANCER RISKS FROM LOW DOSES TO VERY LOW DOSES David J. Brenner* Abstract--There is strong evidence that ionizing <span class="hlt">radiation</span> increases cancer risks at high doses are increased at low doses ( 10 mGy). Discussed here are the issues related to extrapolating <span class="hlt">radiation</span> risks</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://www.math.psu.edu/cao/Papers_PDF/QinFeng-5-9-2011.pdf"><span id="translatedtitle">Pressure-sensitive blackbody point <span class="hlt">radiation</span> <span class="hlt">induced</span> by infrared diode laser irradiation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Cao, Wenwu</p> <p></p> <p>Pressure-sensitive blackbody point <span class="hlt">radiation</span> <span class="hlt">induced</span> by infrared diode laser irradiation Feng Qin,1 of a 980 nm diode laser. The <span class="hlt">radiation</span> was confirmed to be blackbody <span class="hlt">radiation</span>, and it is sensitive with the widely used commercial 980 nm diode laser, which makes it an excellent sensitizing ion [5]. Third</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://www.springerlink.com/index/k646605j68149584.pdf"><span id="translatedtitle">Cosmic-ray <span class="hlt">induced</span> radioactivity in astronauts as a measure of <span class="hlt">radiation</span> dose</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>R. L. Brodzinski; N. A. Wogman; R. W. Perkins</p> <p>1969-01-01</p> <p>The activity-dose-energy relationships for7Be,13N,22Na, and24Na activities <span class="hlt">induced</span> in muscle tissue by proton bombardment have been measured through the energy range up to 580 MeV. The relationship between <span class="hlt">radiation</span> dose and <span class="hlt">induced</span> activity for any given proton bombarding energy is defined. The determination of the <span class="hlt">radiation</span> dose received by an astronaut from cosmic <span class="hlt">radiation</span> of unknown energy by measuring the concentrations</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://hasyweb.desy.de/science/annual_reports/2002_report/part1/contrib/42/7136.pdf"><span id="translatedtitle">Luminescent spectroscopy of GaPO4 and AlPO4 crystals with intrinsic and <span class="hlt">radiation-induced</span> defects</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>V. A. Pustovarov; A. F. Satsepin; M. Kirm; V. S. Cheremnykh</p> <p></p> <p>The practical significance of AlPO4 and GaPO4 crystals is due to the fact that their <span class="hlt">crystalline</span> structure is analogous to the structure of quartz (-SiO2), but the former crystals possess better piezoelectric properties (1). Data on optical and luminescent spectroscopy of these crystals or studies into the <span class="hlt">radiation</span> resistance, regular features of defect formation in the <span class="hlt">crystalline</span> structure, and the</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/51174712"><span id="translatedtitle">Layout-Related Stress Effects on <span class="hlt">Radiation-Induced</span> Leakage Current</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Nadia Rezzak; Ronald D. Schrimpf; Michael L. Alles; En Xia Zhang; Daniel M. Fleetwood; Yanfeng Albert Li</p> <p>2010-01-01</p> <p>The effects of shallow-trench-isolation-<span class="hlt">induced</span> mechanical stress on <span class="hlt">radiation-induced</span> off-state leakage current are reported in 90-nm NMOS devices. The <span class="hlt">radiation-induced</span> leakage current increases with increasing active device-to-isolation spacing. The leakage current also depends on channel width; narrow devices exhibit less leakage before irradiation, but more after irradiation. These geometrical factors affect the mechanical stress in the device, which impact the dopant</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PMC&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3423508"><span id="translatedtitle">Dosimetric Analysis of <span class="hlt">Radiation-Induced</span> Gastric Bleeding</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Feng, Mary; Normolle, Daniel; Pan, Charlie C.; Dawson, Laura A.; Amarnath, Sudha; Ensminger, William D.; Lawrence, Theodore S.; Ten Haken, Randall K.</p> <p>2012-01-01</p> <p>Purpose <span class="hlt">Radiation-induced</span> gastric bleeding has been poorly understood. In this study, we describe dosimetric predictors for gastric bleeding after fractionated radiotherapy and compare several predictive models. Materials & Methods The records of 139 sequential patients treated with 3-dimensional conformal radiotherapy (3D-CRT) for intrahepatic malignancies between January 1999 and April 2002 were reviewed. Median follow-up was 7.4 months. Logistic regression and Lyman normal tissue complication probability (NTCP) models for the occurrence of ? grade 3 gastric bleed were fit to the data. The principle of maximum likelihood was used to estimate parameters for all models. Results Sixteen of 116 evaluable patients (14%) developed gastric bleeds, at a median time of 4.0 months (mean 6.5 months, range 2.1–28.3 months) following completion of RT. The median and mean of the maximum doses to the stomach were 61 and 63 Gy (range 46 Gy–86 Gy), respectively, after bio-correction to equivalent 2 Gy daily fractions. The Lyman NTCP model with parameters adjusted for cirrhosis was most predictive of gastric bleed (AUROC=0.92). Best fit Lyman NTCP model parameters were n =0.10, and m =0.21, with TD50(normal) =56 Gy and TD50(cirrhosis) = 22 Gy. The low n value is consistent with the importance of maximum dose; a lower TD50 value for the cirrhosis patients points out their greater sensitivity. Conclusion This study demonstrates that the Lyman NTCP model has utility for predicting gastric bleeding, and that the presence of cirrhosis greatly increases this risk. These findings should facilitate the design of future clinical trials involving high-dose upper abdominal <span class="hlt">radiation</span>. PMID:22541965</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PMC&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3715464"><span id="translatedtitle">Effect of Epicatechin against <span class="hlt">Radiation-Induced</span> Oral Mucositis: In Vitro and In Vivo Study</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kang, Sung Un; Kim, Jang Hee; Oh, Young-Taek; Park, Keun Hyung; Kim, Chul-Ho</p> <p>2013-01-01</p> <p>Purpose <span class="hlt">Radiation-induced</span> oral mucositis limits the delivery of high-dose <span class="hlt">radiation</span> to head and neck cancer. This study investigated the effectiveness of epicatechin (EC), a component of green tea extracts, on <span class="hlt">radiation-induced</span> oral mucositis in vitro and in vivo. Experimental Design The effect of EC on <span class="hlt">radiation-induced</span> cytotoxicity was analyzed in the human keratinocyte line HaCaT. <span class="hlt">Radiation-induced</span> apoptosis, change in mitochondrial membrane potential (MMP), reactive oxygen species (ROS) generation and changes in the signaling pathway were investigated. In vivo therapeutic effects of EC for oral mucositis were explored in a rat model. Rats were monitored by daily inspections of the oral cavity, amount of oral intake, weight change and survival rate. For histopathologic evaluation, hematoxylin-eosin staining and TUNEL staining were performed. Results EC significantly inhibited <span class="hlt">radiation-induced</span> apoptosis, change of MMP, and intracellular ROS generation in HaCaT cells. EC treatment markedly attenuated the expression of p-JNK, p-38, and cleaved caspase-3 after irradiation in the HaCaT cells. Rats with <span class="hlt">radiation-induced</span> oral mucositis showed decreased oral intake, weight and survival rate, but oral administration of EC significantly restored all three parameters. Histopathologic changes were significantly decreased in the EC-treated irradiated rats. TUNEL staining of rat oral mucosa revealed that EC treatment significantly decreased <span class="hlt">radiation-induced</span> apoptotic cells. Conclusions This study suggests that EC significantly inhibited <span class="hlt">radiation-induced</span> apoptosis in keratinocytes and rat oral mucosa and may be a safe and effective candidate treatment for the prevention of <span class="hlt">radiation-induced</span> mucositis. PMID:23874895</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASA-TRS&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20040087533&hterms=carcinogen&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dcarcinogen"><span id="translatedtitle">Ionizing <span class="hlt">radiation</span> <span class="hlt">induces</span> heritable disruption of epithelial cell interactions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Park, Catherine C.; Henshall-Powell, Rhonda L.; Erickson, Anna C.; Talhouk, Rabih; Parvin, Bahram; Bissell, Mina J.; Barcellos-Hoff, Mary Helen; Chatterjee, A. (Principal Investigator)</p> <p>2003-01-01</p> <p>Ionizing <span class="hlt">radiation</span> (IR) is a known human breast carcinogen. Although the mutagenic capacity of IR is widely acknowledged as the basis for its action as a carcinogen, we and others have shown that IR can also <span class="hlt">induce</span> growth factors and extracellular matrix remodeling. As a consequence, we have proposed that an additional factor contributing to IR carcinogenesis is the potential disruption of critical constraints that are imposed by normal cell interactions. To test this hypothesis, we asked whether IR affected the ability of nonmalignant human mammary epithelial cells (HMEC) to undergo tissue-specific morphogenesis in culture by using confocal microscopy and imaging bioinformatics. We found that irradiated single HMEC gave rise to colonies exhibiting decreased localization of E-cadherin, beta-catenin, and connexin-43, proteins necessary for the establishment of polarity and communication. Severely compromised acinar organization was manifested by the majority of irradiated HMEC progeny as quantified by image analysis. Disrupted cell-cell communication, aberrant cell-extracellular matrix interactions, and loss of tissue-specific architecture observed in the daughters of irradiated HMEC are characteristic of neoplastic progression. These data point to a heritable, nonmutational mechanism whereby IR compromises cell polarity and multicellular organization.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PUBMED&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/8862451"><span id="translatedtitle"><span class="hlt">Radiation-induced</span> chromosome damage in astronauts' lymphocytes.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Testard, I; Ricoul, M; Hoffschir, F; Flury-Herard, A; Dutrillaux, B; Fedorenko, B; Gerasimenko, V; Sabatier, L</p> <p>1996-10-01</p> <p>The increased number of manned space missions has made it important to estimate the biological risks encountered by astronauts. As they are exposed to cosmic rays, especially ions with high linear energy transfer (LET), it is necessary to estimate the doses they receive. The most sensitive biological dosimetry used is based on the quantification of <span class="hlt">radiation-induced</span> chromosome damage to human lymphocytes. After the space missions ANTARES (1992) and ALTAIR (1993), we performed cytogenetic analysis of blood samples from seven astronauts who had spent from 2 weeks to 6 months in space. After 2 or 3 weeks, the X-ray equivalent dose was found to be below the cytogenetic detection level of 20 mGy. After 6 months, the biological dose greatly varied among the astronauts, from 95 to 455 mGy equivalent dose. These doses are in the same range as those estimated by physical dosimetry (90 mGy absorbed dose and 180 mSv equivalent dose). Some blood cells exhibited the same cytogenetic pattern as the 'rogue cells' occasionally observed in controls, but with a higher frequency. We suggest that rogue cells might result from irradiation with high-LET particles of cosmic origin. However, the responsibility of such cells for the long-term effects of cosmic irradiation remains unknown and must be investigated. PMID:8862451</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PMC&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=196872"><span id="translatedtitle">Ionizing <span class="hlt">radiation</span> <span class="hlt">induces</span> heritable disruption of epithelial cell interactions</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Park, Catherine C.; Henshall-Powell, Rhonda L.; Erickson, Anna C.; Talhouk, Rabih; Parvin, Bahram; Bissell, Mina J.; Barcellos-Hoff, Mary Helen</p> <p>2003-01-01</p> <p>Ionizing <span class="hlt">radiation</span> (IR) is a known human breast carcinogen. Although the mutagenic capacity of IR is widely acknowledged as the basis for its action as a carcinogen, we and others have shown that IR can also <span class="hlt">induce</span> growth factors and extracellular matrix remodeling. As a consequence, we have proposed that an additional factor contributing to IR carcinogenesis is the potential disruption of critical constraints that are imposed by normal cell interactions. To test this hypothesis, we asked whether IR affected the ability of nonmalignant human mammary epithelial cells (HMEC) to undergo tissue-specific morphogenesis in culture by using confocal microscopy and imaging bioinformatics. We found that irradiated single HMEC gave rise to colonies exhibiting decreased localization of E-cadherin, ?-catenin, and connexin-43, proteins necessary for the establishment of polarity and communication. Severely compromised acinar organization was manifested by the majority of irradiated HMEC progeny as quantified by image analysis. Disrupted cell–cell communication, aberrant cell–extracellular matrix interactions, and loss of tissue-specific architecture observed in the daughters of irradiated HMEC are characteristic of neoplastic progression. These data point to a heritable, nonmutational mechanism whereby IR compromises cell polarity and multicellular organization. PMID:12960393</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2013JaJAP..52gHF21N"><span id="translatedtitle">Ultrasonic Measurement of Microdisplacement <span class="hlt">Induced</span> by Acoustic <span class="hlt">Radiation</span> Force</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nagaoka, Ryo; Izumi, Takuya; Komatsu, Yosuke; Kobayashi, Kazuto; Saijo, Yoshifumi</p> <p>2013-07-01</p> <p>Quantitative evaluation of human skin aging is achieved by measuring the viscoelasticity of the skin. In the present study, microdisplacement <span class="hlt">induced</span> by acoustic <span class="hlt">radiation</span> force (ARF) is quantitatively measured by high-frequency ultrasonography (HFUS) and the result is confirmed by laser-Doppler velocimetry (LDV). Poly(vinyl alcohol) (PVA) with 1% cellulose particles was used as the biological phantom. A concave piezoelectric zirconate titanate (PZT) transducer with a diameter and focal length of 3 cm was used as an applicator to generate ARF. Microdisplacement at each depth of PVA was measured by the phased tracking method at 100 MHz of ultrasound with a repetition rate of 2000 Hz. When 80 tone-burst pulses were applied, the displacement measured by HFUS was 9 µm and the same result was obtained by LDV. As the displacement at each depth of PVA is measurable using ARF and the HFUS system, the system could be applied to measuring the viscoelasticity of the layered structure of the human skin.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PMC&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3978308"><span id="translatedtitle">Low-dose <span class="hlt">radiation</span> exposure <span class="hlt">induces</span> a HIF-1-mediated adaptive and protective metabolic response</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Lall, R; Ganapathy, S; Yang, M; Xiao, S; Xu, T; Su, H; Shadfan, M; Asara, J M; Ha, C S; Ben-Sahra, I; Manning, B D; Little, J B; Yuan, Z-M</p> <p>2014-01-01</p> <p>Because of insufficient understanding of the molecular effects of low levels of <span class="hlt">radiation</span> exposure, there is a great uncertainty regarding its health risks. We report here that treatment of normal human cells with low-dose <span class="hlt">radiation</span> <span class="hlt">induces</span> a metabolic shift from oxidative phosphorylation to aerobic glycolysis resulting in increased <span class="hlt">radiation</span> resistance. This metabolic change is highlighted by upregulation of genes encoding glucose transporters and enzymes of glycolysis and the oxidative pentose phosphate pathway, concomitant with downregulation of mitochondrial genes, with corresponding changes in metabolic flux through these pathways. Mechanistically, the metabolic reprogramming depends on HIF1?, which is <span class="hlt">induced</span> specifically by low-dose irradiation linking the metabolic pathway with cellular <span class="hlt">radiation</span> dose response. Increased glucose flux and <span class="hlt">radiation</span> resistance from low-dose irradiation are also observed systemically in mice. This highly sensitive metabolic response to low-dose <span class="hlt">radiation</span> has important implications in understanding and assessing the health risks of <span class="hlt">radiation</span> exposure. PMID:24583639</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2008cosp...37..284B"><span id="translatedtitle">Enhanced homologous recombination is <span class="hlt">induced</span> by alpha-particle <span class="hlt">radiation</span> in somatic cells of Arabidopsis thaliana</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bian, Po; Liu, Ping; Wu, Yuejin</p> <p></p> <p>Almost 9 percent of cosmic rays which strike the earth's atmosphere are alpha particles. As one of the ionizing <span class="hlt">radiations</span> (IR), its biological effects have been widely studied. However, the plant genomic instability <span class="hlt">induced</span> by alpha-particle <span class="hlt">radiation</span> was not largely known. In this research, the Arabidopsis thaliana transgenic for GUS recombination substrate was used to evaluate the genomic instability <span class="hlt">induced</span> by alpha-particle <span class="hlt">radiation</span> (3.3MeV). The pronounced effects of systemic exposure to alpha-particle <span class="hlt">radiation</span> on the somatic homologous recombination frequency (HRF) were found at different doses. The 10Gy dose of <span class="hlt">radiation</span> <span class="hlt">induced</span> the maximal HRF which was 1.9-fold higher than the control. The local <span class="hlt">radiation</span> of alpha-particle (10Gy) on root also resulted in a 2.5-fold increase of somatic HRF in non-<span class="hlt">radiated</span> aerial plant, indicating that the signal(s) of genomic instability was transferred to non-<span class="hlt">radiated</span> parts and initiated their genomic instability. Concurrent treatment of seedlings of Arabidopsis thaliana with alpha-particle and DMSO(ROS scavenger) both in systemic and local <span class="hlt">radiation</span> signifi- cantly suppressed the somatic HR, indicating that the free radicals produced by alpha-particle <span class="hlt">radiation</span> took part in the production of signal of genomic instability rather than the signal transfer. Key words: alpha-particle <span class="hlt">radiation</span>, somatic homologous recombination, genomic instability</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PUBMED&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/10540396"><span id="translatedtitle">Hyperbranched Polyether Polyols with Liquid <span class="hlt">Crystalline</span> Properties.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sunder; Quincy; Mülhaupt; Frey</p> <p>1999-10-01</p> <p>The attachment of mesogens as end groups to hyperbranched polyglycerol (degree of polymerization 22-45; see schematic representation, the rigid mesogens are shown as rods and the flexible alkyl chains as lines) leads to liquid <span class="hlt">crystalline</span> polymers with narrow polydispersity, whose liquid <span class="hlt">crystalline</span> behavior is <span class="hlt">induced</span> by the mesogenic end groups only. PMID:10540396</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/30546285"><span id="translatedtitle">HYPERBARIC OXYGEN THERAPY FOR <span class="hlt">RADIATION</span> <span class="hlt">INDUCED</span> HEMORRHAGIC CYSTITIS</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>RANJIV MATHEWS; NATARAJAN RAJAN; LAURA JOSEFSON; ENRICO CAMPORESI; ZAHI MAKHULI</p> <p>1999-01-01</p> <p>Purpose<span class="hlt">Radiation</span> therapy has been used successfully to treat pelvic malignancy but morbidity from hemorrhagic cystitis remains a major long-term sequela in 1 to 2% of patients. Obliterative endarteritis secondary to ionizing <span class="hlt">radiation</span> leads to tissue hypoxia and poor healing. Hyperbaric oxygen therapy has been demonstrated to improve angiogenesis and promote healing in <span class="hlt">radiation</span> injured tissue, including the bladder. We describe</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/41103602"><span id="translatedtitle">Opportunities for nutritional amelioration of <span class="hlt">radiation-induced</span> cellular damage</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Nancy D Turner; Leslie A Braby; John Ford; Joanne R Lupton</p> <p>2002-01-01</p> <p>The closed environment and limited evasive capabilities inherent in space flight cause astronauts to be exposed to many potential harmful agents (chemical contaminants in the environment and cosmic <span class="hlt">radiation</span> exposure). Current power systems used to achieve space flight are prohibitively expensive for supporting the weight requirements to fully shield astronauts from cosmic <span class="hlt">radiation</span>. Therefore, <span class="hlt">radiation</span> poses a major, currently unresolvable</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/1598106"><span id="translatedtitle"><span class="hlt">Radiation-induced</span> damage in GaAs particle detectors</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>R. L. Bates; C. Da Via; A. Pickford; C. Raine; K. M. Smith</p> <p>1997-01-01</p> <p>The motivation for investigating the use of GaAs as a material for detecting particles in experiments for high-energy physics (HEP) arose from its perceived resistance to <span class="hlt">radiation</span> damage. This is a vital requirement for detector materials that are to be used in experiments at future accelerators where the <span class="hlt">radiation</span> environments would exclude all but the most <span class="hlt">radiation</span> resistant of detector</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PMC&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4434101"><span id="translatedtitle">Radioprotective effect of Rapana thomasiana hemocyanin in gamma <span class="hlt">induced</span> acute <span class="hlt">radiation</span> syndrome</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kindekov, Ivan; Mileva, Milka; Krastev, Dimo; Vassilieva, Vladimira; Raynova, Yuliana; Doumanova, Lyuba; Aljakov, Mitko; Idakieva, Krassimira</p> <p>2014-01-01</p> <p>The radioprotective effect of Rapana thomasiana hemocyanin (RtH) against <span class="hlt">radiation-induced</span> injuries (stomach ulcers, survival time and endogenous haemopoiesis) and post-<span class="hlt">radiation</span> recovery was investigated in male albino mice (C3H strain). <span class="hlt">Radiation</span> course was in a dose of 7.5 Gy (LD 100/30 – dose that kills 100% of the mice at 30 days) from 137Cs with a dose of 2.05 Gy/min. <span class="hlt">Radiation</span> injuries were manifested by <span class="hlt">inducing</span> ? hematopoietic form of acute <span class="hlt">radiation</span> syndrome. RtH was administered intraperitoneally in a single dose of 50, 100, 150 and 200 mg/kg body weight (b. w.) once a day for five consecutive days before irradiation. The results obtained showed that <span class="hlt">radiation</span> exposure led to (1) 100% mortality rate, (2) ulceration in the stomach mucosa and (3) decrease formation of spleen colonies as a marker of endogenous haemopoiesis. Administration of RtH at a dose of 200 mg/kg provided better protection against <span class="hlt">radiation-induced</span> stomach ulceration, mitigated the lethal effects of <span class="hlt">radiation</span> exposure and recovered endogenous haemopoiesis versus irradiated but not supplemented mice. It could be expected that RtH will find a use in mitigating <span class="hlt">radiation</span> <span class="hlt">induced</span> injury and enhanced radiorecovery. PMID:26019540</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/22283357"><span id="translatedtitle">A Nonhuman Primate Model of Human <span class="hlt">Radiation-Induced</span> Venocclusive Liver Disease and Hepatocyte Injury</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Yannam, Govardhana Rao [Department of Surgery, University of Nebraska Medical Center, Omaha, Nebraska (United States); Han, Bing [Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); Department of Hepatobiliary Surgery, First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi (China); Setoyama, Kentaro [Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); Yamamoto, Toshiyuki [Department of Surgery, University of Nebraska Medical Center, Omaha, Nebraska (United States); Ito, Ryotaro; Brooks, Jenna M. [Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); Guzman-Lepe, Jorge [Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); Department of Pathology, Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania (United States); Galambos, Csaba [Department of Pathology, Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania (United States); Fong, Jason V. [Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); Deutsch, Melvin; Quader, Mubina A. [Department of Radiation Oncology, Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania (United States); Yamanouchi, Kosho [Department of Radiation Oncology, Albert Einstein College of Medicine, Bronx, New York (United States); Marion Bessin Liver Research Center, Albert Einstein College of Medicine, Bronx, New York (United States); Kabarriti, Rafi; Mehta, Keyur [Department of Radiation Oncology, Albert Einstein College of Medicine, Bronx, New York (United States); Soto-Gutierrez, Alejandro [Department of Pathology, Children's Hospital of Pittsburgh, Pittsburgh, Pennsylvania (United States); McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania (United States); and others</p> <p>2014-02-01</p> <p>Background: Human liver has an unusual sensitivity to <span class="hlt">radiation</span> that limits its use in cancer therapy or in preconditioning for hepatocyte transplantation. Because the characteristic veno-occlusive lesions of <span class="hlt">radiation-induced</span> liver disease do not occur in rodents, there has been no experimental model to investigate the limits of safe <span class="hlt">radiation</span> therapy or explore the pathogenesis of hepatic veno-occlusive disease. Methods and Materials: We performed a dose-escalation study in a primate, the cynomolgus monkey, using hypofractionated stereotactic body radiotherapy in 13 animals. Results: At doses ?40 Gy, animals developed a systemic syndrome resembling human <span class="hlt">radiation-induced</span> liver disease, consisting of decreased albumin, elevated alkaline phosphatase, loss of appetite, ascites, and normal bilirubin. Higher <span class="hlt">radiation</span> doses were lethal, causing severe disease that required euthanasia approximately 10 weeks after <span class="hlt">radiation</span>. Even at lower doses in which <span class="hlt">radiation-induced</span> liver disease was mild or nonexistent, latent and significant injury to hepatocytes was demonstrated by asialoglycoprotein-mediated functional imaging. These monkeys developed hepatic failure with encephalopathy when they received parenteral nutrition containing high concentrations of glucose. Histologically, livers showed central obstruction via an unusual intimal swelling that progressed to central fibrosis. Conclusions: The cynomolgus monkey, as the first animal model of human veno-occlusive <span class="hlt">radiation-induced</span> liver disease, provides a resource for characterizing the early changes and pathogenesis of venocclusion, for establishing nonlethal therapeutic dosages, and for examining experimental therapies to minimize <span class="hlt">radiation</span> injury.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASA-TRS&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20040087647&hterms=Parasite&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DParasite"><span id="translatedtitle"><span class="hlt">Radiation-induced</span> gene expression in the nematode Caenorhabditis elegans</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Nelson, Gregory A.; Jones, Tamako A.; Chesnut, Aaron; Smith, Anna L.</p> <p>2002-01-01</p> <p>We used the nematode C. elegans to characterize the genotoxic and cytotoxic effects of ionizing <span class="hlt">radiation</span> in a simple animal model emphasizing the unique effects of charged particle <span class="hlt">radiation</span>. Here we demonstrate by RT-PCR differential display and whole genome microarray hybridization experiments that gamma rays, accelerated protons and iron ions at the same physical dose lead to unique transcription profiles. 599 of 17871 genes analyzed (3.4%) showed differential expression 3 hrs after exposure to 3 Gy of <span class="hlt">radiation</span>. 193 were up-regulated, 406 were down-regulated and 90% were affected only by a single species of <span class="hlt">radiation</span>. A novel statistical clustering technique identified the regulatory relationships between the <span class="hlt">radiation</span>-modulated genes and showed that genes affected by each <span class="hlt">radiation</span> species were associated with unique regulatory clusters. This suggests that independent homeostatic mechanisms are activated in response to <span class="hlt">radiation</span> exposure as a function of track structure or ionization density.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2015NIMPB.343..167M"><span id="translatedtitle">Ion beam <span class="hlt">induced</span> luminescence (IBIL) system for imaging of <span class="hlt">radiation</span> <span class="hlt">induced</span> changes in materials</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Markovi?, N.; Siketi?, Z.; Cosic, D.; Jung, H. K.; Lee, N. H.; Han, W.-T.; Jakši?, M.</p> <p>2015-01-01</p> <p>The progress of construction on the new IBIL (ion beam <span class="hlt">induced</span> luminescence) spectrometer installed at the ion microprobe facility of the Ru?er Boškovi? Institute (RBI) is reported. The IBIL system can be used with beams from either 6.0 MV Tandem Van de Graaff or 1.0 MV Tandetron accelerators. Components of the new apparatus and current experimental set-up are described in detail. Measurements with the new IBIL system were performed using a 2 MeV proton microbeam on three sets of samples. This paper gives a summary of the IBIL arrangement capabilities for various problems, emphasising the potential of this technique for <span class="hlt">radiation</span> damage studies. Due to the relatively good sensitivity of the IBIL spectrometer, integration into the conventional ion beam analysis (IBA) microbeam setup is shown to be possible.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PMC&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4337597"><span id="translatedtitle">Molecular responses of <span class="hlt">radiation-induced</span> liver damage in rats</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>CHENG, WEI; XIAO, LEI; AINIWAER, AIMUDULA; WANG, YUNLIAN; WU, GE; MAO, RUI; YANG, YING; BAO, YONGXING</p> <p>2015-01-01</p> <p>The aim of the present study was to investigate the molecular responses involved in <span class="hlt">radiation-induced</span> liver damage (RILD). Sprague-Dawley rats (6-weeks-old) were irradiated once at a dose of 20 Gy to the right upper quadrant of the abdomen. The rats were then sacrificed 3 days and 1, 2, 4, 8 and 12 weeks after irradiation and rats, which were not exposed to irradiation were used as controls. Weight measurements and blood was obtained from the rats and liver tissues were collected for histological and apoptotic analysis. Immunohistochemistry, reverse transcription quantitative polymerase chain reaction (RT-qPCR) and western blot analysis were performed to measure the expression levels of mRNAs and proteins, respectively. The serum levels of alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase were increased significantly in the RILD rats. Histological investigation revealed the proliferation of collagen and the formation of fibrotic tissue 12 weeks after irradiation. Apoptotic cells were observed predominantly 2 and 4 weeks after irradiation. The immunohistochemistry, RT-qPCR and western blot analysis all revealed the same pattern of changes in the expression levels of the molecules assessed. The expression levels of transforming growth factor-?1 (TGF-?1), nuclear factor (NF)-?B65, mothers against decapentaplegic homolog 3 (Smad3) and Smad7 and connective tissue growth factor were increased during the recovery period following irradiation up to 12 weeks. The expression levels of tumor necrosis factor-?, Smad7 and Smad4 were only increased during the early phase (first 4 weeks) of recovery following irradiation. In the RILD rat model, the molecular responses indicated that the TGF-?1/Smads and NF-?B65 signaling pathways are involved in the mechanism of RILD recovery. PMID:25483171</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PUBMED&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/25938771"><span id="translatedtitle"><span class="hlt">Radiation-induced</span> epigenetic bystander effects demonstrated in Arabidopsis thaliana.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Xu, Wei; Wang, Ting; Xu, Shuyan; Xu, Shaoxin; Wu, Lijun; Wu, Yuejin; Bian, Po</p> <p>2015-05-01</p> <p><span class="hlt">Radiation-induced</span> bystander effects (RIBE) in vivo in the higher plant Arabidopsis thaliana ( A. thaliana ) have been well demonstrated in terms of effects on development and genetics. However, there is not yet robust evidence regarding RIBE-mediated epigenetic changes in plants. To address this, in the current work the roots of A. thaliana seedlings were locally irradiated with 10 Gy of ? particles, after which DNA methylation in bystander aerial plants were detected using the methylation-sensitive amplification polymorphism (MSAP) and bisulfite sequencing PCR (BSP). Results showed that irradiation of the roots led to long-distance changes in DNA methylation patterns at some CCGG sites over the whole genome, specifically from hemi-methylation to non-methylation, and the methylation ratios, mainly at CG sites, strongly indicating the existence of RIBE-mediated epigenetic changes in higher plants. Root irradiation also influenced expressions of DNA methylation-related MET1, DRM2 and SUVH4 genes and demethylation-related DML3 gene in bystander aerial plants, suggesting a modulation of RIBE to the methylation machinery in plants. In addition, the multicopy P35S:GUS in A. thaliana line L5-1, which is silenced epigenetically by DNA methylation and histone modification, was transcriptionally activated through the RIBE. The transcriptional activation could be significantly inhibited by the treatment with reactive oxygen species (ROS) scavenger dimethyl sulfoxide (DMSO), indicative of a pivotal role of ROS in RIBE-mediated epigenetic changes. Time course analyses showed that the bystander signaling molecule(s) for transcriptional activation of multicopy P35S:GUS, although of unknown chemical nature, were generated in the root cells within 24 h postirradiation. PMID:25938771</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/servlets/purl/770807"><span id="translatedtitle">Synchrotron-<span class="hlt">Radiation</span> <span class="hlt">Induced</span> X-Ray Emission (SRIXE)</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Jones, Keith W.</p> <p>1999-09-01</p> <p>Elemental analysis using emission of characteristic x rays is a well-established scientific method. The success of this analytical method is highly dependent on the properties of the source used to produce the x rays. X-ray tubes have long existed as a principal excitation source, but electron and proton beams have also been employed extensively. The development of the synchrotron <span class="hlt">radiation</span> x-ray source that has taken place during the past 40 years has had a major impact on the general field of x-ray analysis. Even tier 40 years, science of x-ray analysis with synchrotron x-ray beams is by no means mature. Improvements being made to existing synchrotron facilities and the design and construction of new facilities promise to accelerate the development of the general scientific use of synchrotron x-ray sources for at least the next ten years. The effective use of the synchrotron source technology depends heavily on the use of high-performance computers for analysis and theoretical interpretation of the experimental data. Fortunately, computer technology has advanced at least as rapidly as the x-ray technology during the past 40 years and should continue to do so during the next decade. The combination of these technologies should bring about dramatic advances in many fields where synchrotron x-ray science is applied. It is interesting also to compare the growth and rate of acceptance of this particular research endeavor to the rates for other technological endeavors. Griibler [1997] cataloged the time required for introduction, diffusion,and acceptance of technological, economic, and social change and found mean values of 40 to 50 years. The introduction of the synchrotron source depends on both technical and non-technical factors, and the time scale at which this seems to be occurring is quite compatible with what is seen for other major innovations such as the railroad or the telegraph. It will be interesting to see how long the present rate of technological change and increase in scientific use can be maintained for the synchrotron x-ray source. A short summary of the present state of the synchrotron <span class="hlt">radiation-induced</span> x-ray emission (SRIXE) method is presented here. Basically, SRIXE experiments can include any that depend on the detection. of characteristic x-rays produced by the incident x-ray beam born the synchrotron source as they interact with a sample. Thus, experiments done to measure elemental composition, chemical state, crystal, structure, and other sample parameters can be considered in a discussion of SRIXE. It is also clear that the experimentalist may well wish to use a variety of complementary techniques for study of a given sample. For this reason, discussion of computed microtomography (CMT) and x-ray diffraction is included here. It is hoped that this present discussion will serve as a succinct introduction to the basic ideas of SRIXE for those not working in the field and possibly help to stimulate new types of work by those starting in the field as well as by experienced practitioners of the art. The topics covered include short descriptions of (1) the properties of synchrotron <span class="hlt">radiation</span>, (2) a description of facilities used for its production, (3) collimated microprobe, (4) focused microprobes, (5) continuum and monoenergetic excitation, (6) detection limits, (7) quantitation, (8) applications of SRIXE, (9) computed microtomography (CMT), and (10)chemical speciation using x-ray absorption near-edge structure (XANES) and extended x-ray absorption fine structure (EXAFS). An effort has been made to cite a wide variety of work from different laboratories to show the vital nature of the field.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PMC&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3345982"><span id="translatedtitle"><span class="hlt">Radiation-inducible</span> Immunotherapy for Cancer: Senescent Tumor Cells as a Cancer Vaccine</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Meng, Yuru; Efimova, Elena V; Hamzeh, Khaled W; Darga, Thomas E; Mauceri, Helena J.; Fu, Yang-Xin; Kron, Stephen J; Weichselbaum, Ralph R</p> <p>2012-01-01</p> <p>Radiotherapy offers an effective treatment for advanced cancer but local and distant failures remain a significant challenge. Here, we treated melanoma and pancreatic carcinoma in syngeneic mice with ionizing <span class="hlt">radiation</span> (IR) combined with the poly(ADP-ribose) polymerase inhibitor (PARPi) veliparib to inhibit DNA repair and promote accelerated senescence. Based on prior work implicating cytotoxic T lymphocytes (CTLs) as key mediators of <span class="hlt">radiation</span> effects, we discovered that senescent tumor cells <span class="hlt">induced</span> by <span class="hlt">radiation</span> and veliparib express immunostimulatory cytokines to activate CTLs that mediate an effective antitumor response. When these senescent tumor cells were injected into tumor-bearing mice, an antitumor CTL response was <span class="hlt">induced</span> which potentiated the effects of <span class="hlt">radiation</span>, resulting in elimination of established tumors. Applied to human cancers, <span class="hlt">radiation-inducible</span> immunotherapy may enhance radiotherapy responses to prevent local recurrence and distant metastasis. PMID:22334019</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASA-TRS&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20060034866&hterms=plasma+physics&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dplasma%2Bphysics"><span id="translatedtitle">Obtaining Solutions to <span class="hlt">Radiation</span>-And Plasma <span class="hlt">Induced</span> FAilure Modes From Physics</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Frederickson, A.</p> <p>1998-01-01</p> <p>A number of performance-limiting spacecraft problems will be qualitatively discussed: Spacecraft Charging, Deep Dielectric Charging, Solar Cell Arcing, Antenna Sparking, High Voltage Power Shorts, <span class="hlt">Radiation-induced</span> Defects in Semiconductors, and Degradation of Electronic Devices.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PUBMED&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/22384714"><span id="translatedtitle">[DNA-signaling pathway mediating development of a <span class="hlt">radiation-induced</span> bystander effect in human cells].</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ermakov, A V; Kon'kova, M S; Kostiuk, S V; Ve?ko, N N</p> <p>2011-01-01</p> <p>Low doses of ionizing <span class="hlt">radiation</span> <span class="hlt">induce</span> the adaptive effect (AE) development in human cells which is followed by a number of cell responses. These responses can be transmitted from irradiated cells to non-irradiated ones (bystander effect, BE). The major role in <span class="hlt">radiation-induced</span> BE is played by an oxidative stress (OS) and a DNA-signaling pathway, in which extracellular DNA fragments (ecDNA) are the factors of stress-signalization. We propose the following sequence of events in this signaling system: irradiation-OS-DNA modification-apoptosis of irradiated cells-ecDNA-signal acceptance by non-irradiated cells-OS-DNA modification, etc. We observed a <span class="hlt">radiation-induced</span> BE which is accompanied by DNA-signaling pathway in differentiated and undifferentiated human cells forming monolayer or suspension cultures. Here we discuss several aspects of the <span class="hlt">radiation-induced</span> BE mechanism and its persistence possibilities. PMID:22384714</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PUBMED&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/23238079"><span id="translatedtitle">Sulfation of keratan sulfate proteoglycan reduces <span class="hlt">radiation-induced</span> apoptosis in human Burkitt's lymphoma cell lines.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Nakayama, Fumiaki; Umeda, Sachiko; Ichimiya, Tomomi; Kamiyama, Shin; Hazawa, Masaharu; Yasuda, Takeshi; Nishihara, Shoko; Imai, Takashi</p> <p>2013-01-16</p> <p>This study focuses on clarifying the contribution of sulfation to <span class="hlt">radiation-induced</span> apoptosis in human Burkitt's lymphoma cell lines, using 3'-phosphoadenosine 5'-phosphosulfate transporters (PAPSTs). Overexpression of PAPST1 or PAPST2 reduced <span class="hlt">radiation-induced</span> apoptosis in Namalwa cells, whereas the repression of PAPST1 expression enhanced apoptosis. Inhibition of PAPST slightly decreased keratan sulfate (KS) expression, so that depletion of KS significantly increased <span class="hlt">radiation-induced</span> apoptosis. In addition, the repression of all three N-acetylglucosamine-6-O-sulfotransferases (CHST2, CHST6, and CHST7) increased apoptosis. In contrast, PAPST1 expression promoted the phosphorylation of p38 MAPK and Akt in irradiated Namalwa cells. These findings suggest that 6-O-sulfation of GlcNAc residues in KS reduces <span class="hlt">radiation-induced</span> apoptosis of human Burkitt's lymphoma cells. PMID:23238079</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://raraf.org/journal/onco24-7257.pdf"><span id="translatedtitle">ORIGINAL PAPER Ionizing <span class="hlt">radiation</span> <span class="hlt">induces</span> DNA double-strand breaks in bystander primary</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p></p> <p></p> <p>and Genetic Engineering, 148 Zabolotnogo St, Kiev 03143, Ukraine; 3 Center for Radiological Research, CollegeORIGINAL PAPER Ionizing <span class="hlt">radiation</span> <span class="hlt">induces</span> DNA double-strand breaks in bystander primary human</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://dspace.mit.edu/handle/1721.1/67297"><span id="translatedtitle">Irradiated Esophageal Cells are Protected from <span class="hlt">Radiation-Induced</span> Recombination by MnSOD Gene Therapy</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Niu, Yunyun</p> <p></p> <p><span class="hlt">Radiation-induced</span> DNA damage is a precursor to mutagenesis and cytotoxicity. During radiotherapy, exposure of healthy tissues can lead to severe side effects. We explored the potential of mitochondrial SOD (MnSOD) gene ...</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PMC&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4493430"><span id="translatedtitle">The protective effects of trace elements against side effects <span class="hlt">induced</span> by ionizing <span class="hlt">radiation</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2015-01-01</p> <p>Trace elements play crucial role in the maintenance of genome stability in the cells. Many endogenous defense enzymes are containing trace elements such as superoxide dismutase and metalloproteins. These enzymes are contributing in the detoxification of reactive oxidative species (ROS) <span class="hlt">induced</span> by ionizing <span class="hlt">radiation</span> in the cells. Zinc, copper, manganese, and selenium are main trace elements that have protective roles against <span class="hlt">radiation-induced</span> DNA damages. Trace elements in the free salt forms have protective effect against cell toxicity <span class="hlt">induced</span> by oxidative stress, metal-complex are more active in the attenuation of ROS particularly through superoxide dismutase mimetic activity. Manganese-complexes in protection of normal cell against <span class="hlt">radiation</span> without any protective effect on cancer cells are more interesting compounds in this topic. The aim of this paper to review the role of trace elements in protection cells against genotoxicity and side effects <span class="hlt">induced</span> by ionizing <span class="hlt">radiation</span>.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://www.raraf.org/journal/oncog1.pdf"><span id="translatedtitle">Genomic instability and bystander effects <span class="hlt">induced</span> by high-LET <span class="hlt">radiation</span> Eric J Hall*,1</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p></p> <p></p> <p>Genomic instability and bystander effects <span class="hlt">induced</span> by high-LET <span class="hlt">radiation</span> Eric J Hall*,1 and Tom K. There is a progressive increase in genomic instability, determined either by gene amplification or allelic imbalance</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://www.iovs.org/cgi/reprint/44/8/3257.pdf"><span id="translatedtitle">Idiopathic and <span class="hlt">Radiation-Induced</span> Ocular Telangiectasia: The Involvement of the ATM Gene</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Martine Mauget-Faysse; Michele Vuillaume; Maddalena Quaranta; Norman Moullan; Sandra Angele; Marlin D. Friesen; Janet Hall</p> <p>2003-01-01</p> <p>PURPOSE. To investigate whether individuals, with no family history of ataxia telangiectasia (AT), in whom idiopathic or <span class="hlt">radiation-induced</span> ocular telangiectasia developed are carriers of ATM gene mutations. METHODS. The ATM cDNA from lymphoblastoid cell lines estab- lished from 16 patients with idiopathic retinal or choroidal telan- giectasia and 14 patients with <span class="hlt">radiation-induced</span> telangiectasia after radiotherapy for age-related macular degeneration (AMD)</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/44272052"><span id="translatedtitle"><span class="hlt">Radiation-induced</span> absorption in high-purity silica fiber preforms</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>M. O. Zabezhailov; A. L. Tomashuk; I. V. Nikolin; V. G. Plotnichenko</p> <p>2005-01-01</p> <p>The effect of the preform fabrication procedure on the <span class="hlt">radiation-induced</span> absorption in KU-1 and KS-4V high-purity silica glasses was investigated (these glasses are used in fiber preform fabrication via outside fluorosilicate glass deposition on substrate rods and in the rod-in-tube process). The results demonstrate that the deposition of a reflective cladding onto KU-1 rods drastically increases the <span class="hlt">radiation-induced</span> UV absorption</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/60298903"><span id="translatedtitle">The response of kidney to ionizing <span class="hlt">radiation</span> combined with hyperthermia <span class="hlt">induced</span> by ultrasound</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>D. G. Baker; H. T. Sager; D. Elkon; W. Constable; L. Rinehart; M. Wills; J. Savory; D. Lacher</p> <p>1982-01-01</p> <p>Mouse kidneys were made hyperthermic (42.5°C for 30 min) one hour before, during, or one hour after local irradiation to determine the effect of hyperthermia on <span class="hlt">radiation</span> damage. An ultrasound beam was used to <span class="hlt">induce</span> hyperthermia. The urinary concentrations of total protein and albumin were used as criteria of kidney injury. Hyperthermia alone did not <span class="hlt">induce</span> proteinuria. <span class="hlt">Radiation</span> alone produced</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://www.springerlink.com/index/f2j40w44k60v531x.pdf"><span id="translatedtitle">Protection of cellular DNA from ?-<span class="hlt">radiation-induced</span> damages and enhancement in DNA repair by troxerutin</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Dharmendra Kumar Maurya; Sreedevi Balakrishnan; Veena Prakash Salvi; Cherupally Krishnan Krishnan Nair</p> <p>2005-01-01</p> <p>The effect of troxerutin on ?-<span class="hlt">radiation-induced</span> DNA strand breaks in different tissues of mice in vivo and formations of the micronuclei were studied in human peripheral blood lymphocytes ex vivo and mice blood reticulocytes in vivo. Treatments with 1 mM troxerutin significantly inhibited the micronuclei induction in the human lymphocytes. Troxerutin protected\\u000a the human peripheral blood leucocytes from <span class="hlt">radiation-induced</span> DNA</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASA-TRS&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20040141559&hterms=carcinogen&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dcarcinogen"><span id="translatedtitle">The potential influence of <span class="hlt">radiation-induced</span> microenvironments in neoplastic progression</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Barcellos-Hoff, M. H.; Chatterjee, A. (Principal Investigator)</p> <p>1998-01-01</p> <p>Ionizing <span class="hlt">radiation</span> is a complete carcinogen, able both to initiate and promote neoplastic progression and is a known carcinogen of human and murine mammary gland. Tissue response to <span class="hlt">radiation</span> is a composite of genetic damage, cell death and induction of new gene expression patterns. Although DNA damage is believed to initiate carcinogenesis, the contribution of these other aspects of <span class="hlt">radiation</span> response are beginning to be explored. Our studies demonstrate that <span class="hlt">radiation</span> elicits rapid and persistent global alterations in the mammary gland microenvironment. We postulate that <span class="hlt">radiation-induced</span> microenvironments may affect epithelial cells neoplastic transformation by altering their number or susceptibility. Alternatively, <span class="hlt">radiation</span> <span class="hlt">induced</span> microenvironments may exert a selective force on initiated cells and/or be conducive to progression. A key impetus for these studies is the possibility that blocking these events could be a strategy to interrupt neoplastic progression.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/22275829"><span id="translatedtitle">Gamma <span class="hlt">radiation</span> <span class="hlt">induced</span> effects in floppy and rigid Ge-containing chalcogenide thin films</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Ailavajhala, Mahesh S.; Mitkova, Maria [Department of Electrical Engineering, Boise State University, 1910 University Dr. Boise, Idaho 83725-2075 (United States); Gonzalez-Velo, Yago; Barnaby, Hugh; Kozicki, Michael N.; Holbert, Keith [School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, Arizona 85287-9309 (United States); Poweleit, Christian [Department of Physics, Arizona State University, Tempe, Arizona 85287-1504 (United States); Butt, Darryl P. [Department of Material Science and Engineering, Boise State University, 1910 University Dr. Boise, Idaho 83725-2090 (United States)</p> <p>2014-01-28</p> <p>We explore the <span class="hlt">radiation</span> <span class="hlt">induced</span> effects in thin films from the Ge-Se to Ge-Te systems accompanied with silver <span class="hlt">radiation</span> <span class="hlt">induced</span> diffusion within these films, emphasizing two distinctive compositional representatives from both systems containing a high concentration of chalcogen or high concentration of Ge. The studies are conducted on blanket chalcogenide films or on device structures containing also a silver source. Data about the electrical conductivity as a function of the <span class="hlt">radiation</span> dose were collected and discussed based on material characterization analysis. Raman Spectroscopy, X-ray Diffraction Spectroscopy, and Energy Dispersive X-ray Spectroscopy provided us with data about the structure, structural changes occurring as a result of <span class="hlt">radiation</span>, molecular formations after Ag diffusion into the chalcogenide films, Ag lateral diffusion as a function of <span class="hlt">radiation</span> and the level of oxidation of the studied films. Analysis of the electrical testing suggests application possibilities of the studied devices for <span class="hlt">radiation</span> sensing for various conditions.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PUBMED&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/20486661"><span id="translatedtitle">Sodium bicarbonate <span class="hlt">induces</span> <span class="hlt">crystalline</span> wax generation, activates host-resistance, and increases imazalil level in rind wounds of oranges, improving the control of green mold during storage.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dore, Antonio; Molinu, Maria Giovanna; Venditti, Tullio; D'Hallewin, Guy</p> <p>2010-06-23</p> <p>Imazalil (IMZ) was quantified in the flavedo and albedo (Citrus fruits outer and inner tissue of the exocarp) of wounded and unwounded Valencia L. Olinda oranges following a 2 min immersion at 25 degrees C in 50, 100, or 250 microg mL(-1) of the fungicide mixture with or without 3% sodium bicarbonate (SBC). The addition of SBC significantly reduced the decay incidence throughout 30 d of storage at 10 degrees C with 95% RH and 6 d of simulated marketing period at 25 degrees C and 75% RH. In unwounded oranges, IMZ uptake was not changed by the coapplication of SBC, and the fungicide was predominantly recovered in the flavedo. To the contrary, in the albedo of wounded fruit, the residue level increased by about 6-fold when the fungicide was applied with SBC. When SBC was coapplied to wounded fruit, the phytoalexin scoparone was <span class="hlt">induced</span> in the albedo and the accumulation was not affected by IMZ. When fruit was treated with SBC, scanning electron microscopy observations evidenced a production of <span class="hlt">crystalline</span> wax patches with branched stripes and the magnitude was positively correlated to the salt concentration in the mixture. The generation as fast as 24 h post-treatment, and the different morphology of the new wax suggests a displacement of intracuticular waxes which can affect the fungicide sorption and diffusion coefficient into the rind. PMID:20486661</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PMC&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3427298"><span id="translatedtitle">Exposure to Heavy Ion <span class="hlt">Radiation</span> <span class="hlt">Induces</span> Persistent Oxidative Stress in Mouse Intestine</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Datta, Kamal; Suman, Shubhankar; Kallakury, Bhaskar V. S.; Fornace, Albert J.</p> <p>2012-01-01</p> <p>Ionizing <span class="hlt">radiation-induced</span> oxidative stress is attributed to generation of reactive oxygen species (ROS) due to radiolysis of water molecules and is short lived. Persistent oxidative stress has also been observed after <span class="hlt">radiation</span> exposure and is implicated in the late effects of <span class="hlt">radiation</span>. The goal of this study was to determine if long-term oxidative stress in freshly isolated mouse intestinal epithelial cells (IEC) is dependent on <span class="hlt">radiation</span> quality at a dose relevant to fractionated radiotherapy. Mice (C57BL/6J; 6 to 8 weeks; female) were irradiated with 2 Gy of ?-rays, a low-linear energy transfer (LET) <span class="hlt">radiation</span>, and intestinal tissues and IEC were collected 1 year after <span class="hlt">radiation</span> exposure. Intracellular ROS, mitochondrial function, and antioxidant activity in IEC were studied by flow cytometry and biochemical assays. Oxidative DNA damage, cell death, and mitogenic activity in IEC were assessed by immunohistochemistry. Effects of ? <span class="hlt">radiation</span> were compared to 56Fe <span class="hlt">radiation</span> (iso-toxic dose: 1.6 Gy; energy: 1000 MeV/nucleon; LET: 148 keV/µm), we used as representative of high-LET <span class="hlt">radiation</span>, since it's one of the important sources of high Z and high energy (HZE) <span class="hlt">radiation</span> in cosmic rays. <span class="hlt">Radiation</span> quality affected the level of persistent oxidative stress with higher elevation of intracellular ROS and mitochondrial superoxide in high-LET 56Fe <span class="hlt">radiation</span> compared to unirradiated controls and ? <span class="hlt">radiation</span>. NADPH oxidase activity, mitochondrial membrane damage, and loss of mitochondrial membrane potential were greater in 56Fe-irradiated mice. Compared to ? <span class="hlt">radiation</span> oxidative DNA damage was higher, cell death ratio was unchanged, and mitotic activity was increased after 56Fe <span class="hlt">radiation</span>. Taken together our results indicate that long-term functional dysregulation of mitochondria and increased NADPH oxidase activity are major contributing factors towards heavy ion <span class="hlt">radiation-induced</span> persistent oxidative stress in IEC with potential for neoplastic transformation. PMID:22936983</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/50025171"><span id="translatedtitle">Detection of environmental ultraviolet <span class="hlt">radiation</span> by the <span class="hlt">induced</span> electroluminescence in a ceramic detector</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Ching-shen Su</p> <p>1995-01-01</p> <p>Environmental ultraviolet (UV) <span class="hlt">radiation</span> can be detected passively by a ceramic sensor with the method of recording the <span class="hlt">radiation</span> <span class="hlt">induced</span> electroluminescence (EL). The phenomenon that metal-oxide ceramic material doped with certain impurities can emit photons under high electric field after the irradiation of UV has been found in our laboratory. This phenomenon of EL can only exist when the sensor</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/56240770"><span id="translatedtitle">Novel method for preventing solar ultraviolet-<span class="hlt">radiation-induced</span> skin cancer</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Weimin Shi; Ting Cui; George H. Sigel</p> <p>1991-01-01</p> <p>Skin cancers are most common cancers in human populations, with more than 550,000 new cases annually in the United States, representing at least 30% of annual primary cancer diagnosed. It has been well recognized that solar ultraviolet <span class="hlt">radiation</span> is the predominant causal factor in cutaneous carcinogenesis in humans. The risk degree of solar ultraviolet <span class="hlt">radiation</span> in terms of <span class="hlt">inducing</span> skin</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/26412530"><span id="translatedtitle">Effect of <span class="hlt">radiation</span> <span class="hlt">induced</span> deep level traps on Si detector performance</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>V. Eremin; E. Verbitskaya; Z. Li</p> <p>2002-01-01</p> <p>The main factor, which leads to semiconductor detector degradation in high-energy physics experiments, is the introduction of lattice defects in the detector material produced by <span class="hlt">radiation</span>. Based on the spectrum of <span class="hlt">radiation</span> <span class="hlt">induced</span> defects in the silicon bulk, the overview of effects and mechanisms responsible for the changes in the main detector parameters such as effective concentration of the space</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://www.cumc.columbia.edu/dept/radoncology/raraf/journal/pone.0028559.pdf"><span id="translatedtitle"><span class="hlt">Radiation-Induced</span> Carcinogenesis: Mechanistically Based Differences between Gamma-Rays and Neutrons, and</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Brenner, David Jonathan</p> <p></p> <p><span class="hlt">Radiation-Induced</span> Carcinogenesis: Mechanistically Based Differences between Gamma-Rays and Neutrons effect). Densely ionizing <span class="hlt">radiation</span> (e.g. neutrons) often produces downwardly curving dose responses exposed to high or low dose rates of c-rays and neutrons, either with or without pre</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://www.springerlink.com/index/xv63hq7552868pl1.pdf"><span id="translatedtitle">Glycerol as a chemical chaperone enhances <span class="hlt">radiation-induced</span> apoptosis in anaplastic thyroid carcinoma cells</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Ken Ohnishi; Ichiro Ota; Katsunari Yane; Akihisa Takahashi; Kazue Yuki; Mie Emoto; Hiroshi Hosoi; Takeo Ohnishi</p> <p>2002-01-01</p> <p>INTRODUCTION: Anaplastic thyroid carcinoma, which is one of the most aggressive, malignant tumors in humans, results in an extremely poor prognosis despite chemotherapy and radiotherapy. The present study was designed to evaluate therapeutic effects of <span class="hlt">radiation</span> by glycerol on p53-mutant anaplastic thyroid carcinoma cells (8305c cells). To examine the effectiveness of glycerol in <span class="hlt">radiation</span> <span class="hlt">induced</span> lethality for anaplastic thyroid carcinoma</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/48575289"><span id="translatedtitle">Moist Skin Care Can Diminish Acute<span class="hlt">Radiation-Induced</span> Skin Toxicity</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Felix Momm; Christian Weißenberger; Susanne Bartelt; Michael Henke</p> <p>2003-01-01</p> <p>Background: <span class="hlt">Radiation</span> treatment may <span class="hlt">induce</span> acute skin reactions. There are several methods of managing them. Validity of these methods, however, is not sufficiently studied. We therefore investigated, whether moist skin care with 3% urea lotion will reduce acute <span class="hlt">radiation</span> skin toxicity. Patients and Methods: 88 patients with carcinomas of the head and neck undergoing radiotherapy with curative intent (mean total</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://www.nature.com/cddis/journal/v4/n6/pdf/cddis2013227a.pdf"><span id="translatedtitle">Repression of ATR pathway by miR-185 enhances <span class="hlt">radiation-induced</span> apoptosis and proliferation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Cai, Long</p> <p></p> <p>of miR-34a expression may be responsible for important protective mechanisms counteracting <span class="hlt">radiation</span>OPEN Repression of ATR pathway by miR-185 enhances <span class="hlt">radiation-induced</span> apoptosis and proliferation and their downstream genes. Disruption of these signaling pathways leads to genome instability and cell death, and thus</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/21000532"><span id="translatedtitle">Curvature-<span class="hlt">induced</span> <span class="hlt">radiation</span> of surface plasmon polaritons propagating around bends</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Hasegawa, Keisuke; Noeckel, Jens U.; Deutsch, Miriam [Department of Physics, University of Oregon, 1371 East 13th Aveenue, Eugene, Oregon 97403 (United States)</p> <p>2007-06-15</p> <p>We present a theoretical study of the curvature-<span class="hlt">induced</span> <span class="hlt">radiation</span> of surface plasmon polaritons propagating around bends at metal-dielectric interfaces. We explain qualitatively how the curvature leads to distortion of the phase front, causing the fields to <span class="hlt">radiate</span> energy away from the metal-dielectric interface. We then quantify, both analytically and numerically, <span class="hlt">radiation</span> losses and energy transmission efficiencies of surface plasmon polaritons propagating around bends with varying radii as well as sign of curvature.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PMC&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4194292"><span id="translatedtitle">Mechanisms of <span class="hlt">radiation-induced</span> normal tissue toxicity and implications for future clinical trials</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Jenrow, Kenneth A.; Brown, Stephen L.</p> <p>2014-01-01</p> <p>To summarize current knowledge regarding mechanisms of <span class="hlt">radiation-induced</span> normal tissue injury and medical countermeasures available to reduce its severity. Advances in <span class="hlt">radiation</span> delivery using megavoltage and intensity-modulated <span class="hlt">radiation</span> therapy have permitted delivery of higher doses of <span class="hlt">radiation</span> to well-defined tumor target tissues. Injury to critical normal tissues and organs, however, poses substantial risks in the curative treatment of cancers, especially when <span class="hlt">radiation</span> is administered in combination with chemotherapy. The principal pathogenesis is initiated by depletion of tissue stem cells and progenitor cells and damage to vascular endothelial microvessels. Emerging concepts of <span class="hlt">radiation-induced</span> normal tissue toxicity suggest that the recovery and repopulation of stromal stem cells remain chronically impaired by long-lived free radicals, reactive oxygen species, and pro-inflammatory cytokines/chemokines resulting in progressive damage after <span class="hlt">radiation</span> exposure. Better understanding the mechanisms mediating interactions among excessive generation of reactive oxygen species, production of pro-inflammatory cytokines and activated macrophages, and role of bone marrow-derived progenitor and stem cells may provide novel insight on the pathogenesis of <span class="hlt">radiation-induced</span> injury of tissues. Further understanding the molecular signaling pathways of cytokines and chemokines would reveal novel targets for protecting or mitigating <span class="hlt">radiation</span> injury of tissues and organs. PMID:25324981</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2014JCrGr.405..131T"><span id="translatedtitle">Defect formation <span class="hlt">induced</span> by seed-joints during directional solidification of quasi-mono-<span class="hlt">crystalline</span> silicon ingots</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Trempa, M.; Reimann, C.; Friedrich, J.; Müller, G.; Krause, A.; Sylla, L.; Richter, T.</p> <p>2014-11-01</p> <p>In this work, the growth behavior inside and above seed gaps during directional solidification of monocrystalline lab-scale silicon ingots was investigated. It will be shown that the silicon melt fills the gaps rapidly and monocrystalline growth starts in most cases at the seed side walls toward the gap center. During this process, dislocations were <span class="hlt">induced</span> at the seed edges and in the gap center by the thermal shock caused by the hot melt and the coalescence of the two growth interfaces, respectively. The dislocations originating from the gap are propagating more or less parallel to the growth axis toward the top of the crystal. These dislocation bundles fan out in dependence of the growth height and axial seed orientation, respectively. It was found that <1 0 0> is the most suitable growth direction in comparison to <1 1 1> and <1 1 0> to avoid defect clusters above the seed gaps which is probably due to the orientation of the preferential glide systems.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PUBMED&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/18080303"><span id="translatedtitle">Mechanism of calcium disilicide-<span class="hlt">induced</span> calcification of <span class="hlt">crystalline</span> silicon surfaces in simulated body fluid under zero bias.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Seregin, Vladimir V; Coffer, Jeffery L</p> <p>2008-10-01</p> <p>A dry-etch spark ablation method was used to produce calcium disilicide (CaSi2/Si) layers on silicon surfaces, and their biomineralization under zero bias was followed by means of scanning electron microscopy, X-ray energy dispersive analysis, and Raman spectroscopy. CaSi2/Si wafers are bioinert at 25 degrees C and bioactive at 37 degrees C. Mechanistic insights regarding biomineralization were derived from an analysis of film growth morphology and chemical composition after various soaking periods in standard simulated body fluid (SBF). Changes in CaSi2/Si calcification behavior as a function of reaction temperature and pH, SBF concentration, and various surface modification processes were also employed for this purpose. During CaSi2/Si calcification under zero bias, calcium phosphate (CaP) growth is strongly dependent on the structural degradation of CaSi2/Si grains. Surface silanol groups, initially present on the as-prepared material, cannot <span class="hlt">induce</span> CaP nucleation, which begins only upon delamination of CaSi2/Si layers. The calcium phosphate phases, which are present during various growth stages, possibly include a combination of Mg-substituted whitlockite, monetite, and tricalcium phosphate. PMID:18080303</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASA-TRS&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20040087727&hterms=BYSTANDER&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DBYSTANDER"><span id="translatedtitle">Non-targeted and delayed effects of exposure to ionizing <span class="hlt">radiation</span>: I. <span class="hlt">Radiation-induced</span> genomic instability and bystander effects in vitro</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Morgan, William F.</p> <p>2003-01-01</p> <p>A long-standing dogma in the <span class="hlt">radiation</span> sciences is that energy from <span class="hlt">radiation</span> must be deposited in the cell nucleus to elicit a biological effect. A number of non-targeted, delayed effects of ionizing <span class="hlt">radiation</span> have been described that challenge this dogma and pose new challenges to evaluating potential hazards associated with <span class="hlt">radiation</span> exposure. These effects include <span class="hlt">induced</span> genomic instability and non-targeted bystander effects. The in vitro evidence for non-targeted effects in <span class="hlt">radiation</span> biology will be reviewed, but the question as to how one extrapolates from these in vitro observations to the risk of <span class="hlt">radiation-induced</span> adverse health effects such as cancer remains open.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASA-TRS&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20090014108&hterms=experiment+human&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3Dexperiment%2Bhuman"><span id="translatedtitle">M-BAND Study of <span class="hlt">Radiation-Induced</span> Chromosome Aberrations in Human Epithelial Cells: <span class="hlt">Radiation</span> Quality and Dose Rate Effects</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hada, Megumi; Cucinotta, Francis; Wu, Honglu</p> <p>2009-01-01</p> <p>The advantage of the multicolor banding in situ hybridization (mBAND) technique is its ability to identify both inter- (translocation to unpainted chromosomes) and intra- (inversions and deletions within a single painted chromosome) chromosome aberrations simultaneously. To study the detailed rearrangement of low- and high-LET <span class="hlt">radiation</span> <span class="hlt">induced</span> chromosome aberrations in human epithelial cells (CH184B5F5/M10) in vitro, we performed a series of experiments with Cs-137 gamma rays of both low and high dose rates, neutrons of low dose rate and 600 MeV/u Fe ions of high dose rate, with chromosome 3 painted with multi-binding colors. We also compared the chromosome aberrations in both 2- and 3-dimensional cell cultures. Results of these experiments revealed the highest chromosome aberration frequencies after low dose rate neutron exposures. However, detailed analysis of the <span class="hlt">radiation</span> <span class="hlt">induced</span> inversions revealed that all three <span class="hlt">radiation</span> types <span class="hlt">induced</span> a low incidence of simple inversions. Most of the inversions in gamma-ray irradiated samples were accompanied by other types of intra-chromosomal aberrations but few inversions were accompanied by inter-chromosomal aberrations. In contrast, neutrons and Fe ions <span class="hlt">induced</span> a significant fraction of inversions that involved complex rearrangements of both inter- and intrachromosomal exchanges. The location of the breaks involved in chromosome exchanges was analyzed along the painted chromosome. The breakpoint distribution was found to be randomly localized on chromosome 3 after neutron or Fe ion exposure, whereas non-random distribution with clustering breakpoints was observed after -ray exposure. Our comparison of chromosome aberration yields between 2- and 3-dimensional cell cultures indicated a significant difference for gamma exposures, but not for Fe ion exposures. These experimental results indicated that the track structure of the <span class="hlt">radiation</span> and the cellular/chromosome structure can both affect <span class="hlt">radiation-induced</span> chromosome aberrations.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/servlets/purl/5622389"><span id="translatedtitle">Early mechanisms in <span class="hlt">radiation-induced</span> biological damage</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Powers, E.L.</p> <p>1983-01-01</p> <p>An introduction to the mechanisms of <span class="hlt">radiation</span> action in biological systems is presented. Several questions about the nature of the <span class="hlt">radiation</span> damage process are discussed, including recognition of the oxygen effects, dose-response relationships, and the importance of the hydroxyl radical. (ACR)</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/21554517"><span id="translatedtitle"><span class="hlt">Radiation-induced</span> mechanical property changes in filled rubber</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Maiti, A.; Weisgraber, T. H.; Gee, R. H.; Small, W.; Alviso, C. T.; Chinn, S. C.; Maxwell, R. S. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States)</p> <p>2011-06-15</p> <p>In a recent paper we exposed a filled elastomer to controlled <span class="hlt">radiation</span> dosages and explored changes in its cross-link density and molecular weight distribution between network junctions [A. Maiti et al., Phys. Rev. E 83, 031802 (2011)]. Here we report mechanical response measurements when the material is exposed to <span class="hlt">radiation</span> while being under finite nonzero strain. We observe interesting hysteretic behavior and material softening representative of the Mullins effect, and materials hardening due to <span class="hlt">radiation</span>. The net magnitude of the elastic modulus depends upon the <span class="hlt">radiation</span> dosage, strain level, and strain-cycling history of the material. Using the framework of Tobolsky's two-stage independent network theory we develop a model that can quantitatively interpret the observed elastic modulus and its <span class="hlt">radiation</span> and strain dependence.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2012PhDT.......117F"><span id="translatedtitle"><span class="hlt">Radiation</span> <span class="hlt">Induced</span> Segregation in High Chromium Ferritic/Martensitic Steels</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Field, Kevin G.</p> <p></p> <p>High Cr ferritic/martensitic (F/M) steels including nano-featured oxide dispersion strengthened steels (NF-ODS) are a candidate material class for advanced fission and fusion nuclear reactor designs. F/M steels have excellent high temperature strength, low swelling rates and the recent developments in NF-ODS steels has improved their high temperature creep performance. A concern for F/M steels is their <span class="hlt">radiation</span> <span class="hlt">induced</span> segregation (RIS) response while in-service. RIS occurs when atomic fluxes preferentially couple to point defect fluxes to defect sinks such as grain boundaries (GBs). For F/M steels no conclusive trends or dependencies on the RIS response have been drawn. Interfaces, including grain boundaries and precipitate-matrix interfaces can alter the RIS response. The grain boundary structure could change the point defect interaction at the GB. Changes in the point defect kinetics at a grain boundary could therefore alter the RIS response at the boundary. Furthermore, oxide nanoclusters in NF-ODS steel act as sinks for point defects under irradiation. The surface area and number density of these nanoclusters in NF-ODS steels could alter the point defect fluxes to GBs. Analytical microscopy techniques were conducted to determine the role of grain boundary structure and nanocluster dispersion on the RIS response in irradiated F/M steels. Here, a 9 wt. % Cr model alloy which simulates the structure of commercially available steels and 14YWT NF-ODS alloy was irradiated under numerous conditions. Both alloys were investigated using STEM/EDS and GB misorientation analysis. Experimental results indicate a preferential segregation of Cr to specific GB misorientations in the model F/M steel. Findings in the NF-ODS alloy indicates the stability of nanoclusters within the alloy alters the concentration gradient of the point defects near irradiated GBs. Based on these results, new theories on the role of interfaces in irradiated F/M steels was developed including a rate theory model which accounts for the GB misorientation angle within the RIS model. These theories will stimulate the development of new F/M steels which are highly resistant to RIS while in-service.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/49225153"><span id="translatedtitle">Simulation of ion beam <span class="hlt">induced</span> current in <span class="hlt">radiation</span> detectors and microelectronic devices</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Gyorgy Vizkelethy</p> <p>2011-01-01</p> <p>Ion Beam <span class="hlt">Induced</span> Charge (IBIC) is the basic mechanism of the operation of semiconductor detectors and it can lead to Single Event Effects (SEEs) in microelectronic devices. To be able to predict SEEs in ICs and detector responses one needs to be able to simulate the <span class="hlt">radiation-induced</span> current as the function of time on the electrodes of the devices and</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2015ApSS..332..726J"><span id="translatedtitle">Studies of dense electronic excitation-<span class="hlt">induced</span> modification in <span class="hlt">crystalline</span> Fe-doped SnO2 thin films</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jaiswal, Manoj Kumar; Kumar, Rajesh; Kanjilal, D.; Dong, C. L.; Chen, C. L.; Asokan, K.; Ojha, S.</p> <p>2015-03-01</p> <p>Dense electronic excitation-<span class="hlt">induced</span> modification in thin films of Fe-doped tin oxide (SnO2) grown by RF sputtering technique was done by irradiating swift heavy ion (SHI) beams of 100 MeV Au8+ with varying ion fluencies from 5 × 1011 to 1 × 1013 ions/cm2. While the AFM results exhibit grain size dependence on irradiation fluence, MFM images show uniformly distributed magnetized nanoparticles over the entire surface after irradiation. GAXRD pattern indicates particle size variation (from 5 to 26 nm) due to irradiation and higher stability of (1 0 1) other planes against irradiation. Our reported results show that the surface energies of ESurf(1 0 1) > ESurf(1 1 0) in rutile structure of SnO2. Change in optical band gap between 3.78 and 5.08 eV due to variation fluence was observed. This is attributed to variation in particle size, scattering due to surface roughness and modification in local electronic structure. RT magnetic studies done by SQUID shows that coercivity increases up to the fluence of 5 × 1012 ions/cm2 (157.71 Oe). The increase in coercivity is due to oxygen vacancies created and change in local electronic structure of Sn due to recoil implantation. Resonance RBS results confirm the presence of Fe in the samples with a new observation where increase in peak intensity of Sn after irradiation occurred. The presence of X-ray absorption near-edge structure spectra at O K-edge around 532.63 eV in pristine and irradiated samples confirms the doping of Fe at the lattice site of Sn in SnO2. Evolution of new spectral features at 486.09, 486.75, 491.40, 492.85 and 499.14 eV for XANES at Sn M-edge was obtained after irradiation.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PMC&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3998761"><span id="translatedtitle">Numbers and proportions of leukemias in young people and adults <span class="hlt">induced</span> by <span class="hlt">radiation</span> of natural origin</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kendall, Gerald; Little, Mark; Wakeford, Richard</p> <p>2014-01-01</p> <p>Natural sources contribute a large fraction of the <span class="hlt">radiation</span> exposure of the general public. Under the linear no-threshold hypothesis risk decreases in proportion to decreasing dose without a threshold. We use recent estimates of doses to the red bone marrow to calculate the number and proportion of cases of leukemia in England <span class="hlt">induced</span> by natural <span class="hlt">radiation</span>. We calculate that 5–6% of cases of leukemia, excluding chronic lymphocytic leukemia, up to age 80 years are <span class="hlt">induced</span> by this background <span class="hlt">radiation</span>. In young people up to the age of 25 years the attributable fraction is 12–18%, substantially lower than a previous estimate. PMID:21334745</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PUBMED&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/21846069"><span id="translatedtitle">[A case of prednisolone therapy for <span class="hlt">radiation-induced</span> hemorrhagic cystitis].</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yanagi, Masato; Nishimura, Taiji; Kurita, Susumu; Lee, Chorsu; Kondo, Yukihiro; Yamazaki, Keiichi</p> <p>2011-05-01</p> <p>Hemorrhagic cystitis resulting from <span class="hlt">radiation</span> to pelvic visceral malignant lesions often might be incurable and there have been no established definitive treatment. We experienced a case with severe <span class="hlt">radiation-induced</span> hemorrhagic cystitis refractory to conventional therapy. The treatment with oral administration of prednisolone was performed and obtained a successful result. Gross hematuria disappeared in 2 weeks in this case. This experience suggested that oral administration of prednisolone could be considered the treatment for patients with <span class="hlt">radiation-induced</span> hemorrhagic cystitis when usual treatments including transurethral electro-coagulation are unsuccessful. PMID:21846069</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PMC&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2913836"><span id="translatedtitle">Prophylaxis and management of acute <span class="hlt">radiation-induced</span> skin reactions: a systematic review of the literature</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Salvo, N.; Barnes, E.; van Draanen, J.; Stacey, E.; Mitera, G.; Breen, D.; Giotis, A.; Czarnota, G.; Pang, J.; De Angelis, C.</p> <p>2010-01-01</p> <p><span class="hlt">Radiation</span> therapy is a common treatment for cancer patients. One of the most common side effects of <span class="hlt">radiation</span> is acute skin reaction (<span class="hlt">radiation</span> dermatitis) that ranges from a mild rash to severe ulceration. Approximately 85% of patients treated with <span class="hlt">radiation</span> therapy will experience a moderate-to-severe skin reaction. Acute <span class="hlt">radiation-induced</span> skin reactions often lead to itching and pain, delays in treatment, and diminished aesthetic appearance—and subsequently to a decrease in quality of life. Surveys have demonstrated that a wide variety of topical, oral, and intravenous agents are used to prevent or to treat <span class="hlt">radiation-induced</span> skin reactions. We conducted a literature review to identify trials that investigated products for the prophylaxis and management of acute <span class="hlt">radiation</span> dermatitis. Thirty-nine studies met the pre-defined criteria, with thirty-three being categorized as prophylactic trials and six as management trials. For objective evaluation of skin reactions, the <span class="hlt">Radiation</span> Therapy Oncology Group criteria and the U.S. National Cancer Institute Common Toxicity Criteria were the most commonly used tools (65% of the studies). Topical corticosteroid agents were found to significantly reduce the severity of skin reactions; however, the trials of corticosteroids evaluated various agents, and no clear indication about a preferred corticosteroid has emerged. Amifostine and oral enzymes were somewhat effective in preventing <span class="hlt">radiation-induced</span> skin reactions in phase ii and phase iii trials respectively; further large randomized controlled trials should be undertaken to better investigate those products. Biafine cream (Ortho–McNeil Pharmaceuticals, Titusville, NJ, U.S.A.) was found not to be superior to standard regimes in the prevention of <span class="hlt">radiation-induced</span> skin reactions (n = 6). In conclusion, the evidence is insufficient to support the use of a particular agent for the prevention and management of acute <span class="hlt">radiation-induced</span> skin reactions. Future trials should focus on comparing agents and approaches that, in phase i and ii trials, suggest efficacy. These future phase iii randomized controlled trials must clearly distinguish between preventive and management strategies for <span class="hlt">radiation-induced</span> dermatitis. Only then can evidence-based guidelines be developed, with the hope of standardizing the approach across centres and of improving the prevention and management of <span class="hlt">radiation-induced</span> dermatitis. PMID:20697521</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PUBMED&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/23175338"><span id="translatedtitle">Bystander effect <span class="hlt">induced</span> by UV <span class="hlt">radiation</span>; why should we be interested?</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Widel, Maria</p> <p>2012-01-01</p> <p>The bystander effect, whose essence is an interaction of cells directly subjected to <span class="hlt">radiation</span> with adjacent non-subjected cells, via molecular signals, is an important component of ionizing <span class="hlt">radiation</span> action. However, knowledge of the bystander effect in the case of ultraviolet (UV) <span class="hlt">radiation</span> is quite limited. Reactive oxygen and nitrogen species generated by UV in exposed cells <span class="hlt">induce</span> bystander effects in non-exposed cells, such as reduction in clonogenic cell survival and delayed cell death, oxidative DNA damage and gene mutations, induction of micronuclei, lipid peroxidation and apoptosis. Although the bystander effect after UV <span class="hlt">radiation</span> has been recognized in cell culture systems, its occurrence in vivo has not been studied. However, solar UV <span class="hlt">radiation</span>, which is the main source of UV in the environment, may <span class="hlt">induce</span> in human dermal tissue an inflammatory response and immune suppression, events which can be considered as bystander effects of UV <span class="hlt">radiation</span>. The oxidative damage to DNA, genomic instability and the inflammatory response may lead to carcinogenesis. UV <span class="hlt">radiation</span> is considered one of the important etiologic factors for skin cancers, basal- and squamous-cell carcinomas and malignant melanoma. Based on the mechanisms of actions it seems that the UV-<span class="hlt">induced</span> bystander effect can have some impact on skin damage (carcinogenesis?), and probably on cells of other tissues. The paper reviews the existing data about the UV-<span class="hlt">induced</span> bystander effect and discusses a possible implication of this phenomenon for health risk.  PMID:23175338</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PUBMED&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/22439436"><span id="translatedtitle">Amelioration of ionizing <span class="hlt">radiation</span> <span class="hlt">induced</span> lipid peroxidation in mouse liver by Moringa oleifera Lam. leaf extract.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sinha, Mahuya; Das, Dipesh Kr; Datta, Sanjukta; Ghosh, Santinath; Dey, Sanjit</p> <p>2012-03-01</p> <p>Protective effect of Moringa oleifera leaf extract (MoLE) against <span class="hlt">radiation-induced</span> lipid peroxidation has been investigated. Swiss albino mice, selected from an inbred colony, were administered with MoLE (300 mg/kg body wt) for 15 days before exposing to a single dose of 5 Gy 60Co-gamma <span class="hlt">radiation</span>. After treatments, animals were necropsied at different post irradiation intervals (days 1, 7 and 15) and hepatic lipid peroxidation and reduced glutathione (GSH) contents were estimated to observe the relative changes due to irradiation and its possible amelioration by MoLE. It was observed that, MoLE treatment restored GSH in liver and prevented <span class="hlt">radiation</span> <span class="hlt">induced</span> augmentation in hepatic lipid peroxidation. Phytochemical analysis showed that MoLE possess various phytochemicals such as ascorbic acid, phenolics (catechin, epicatechin, ferulic acid, ellagic acid, myricetin) etc., which may play the key role in prevention of hepatic lipid peroxidation by scavenging <span class="hlt">radiation</span> <span class="hlt">induced</span> free radicals. PMID:22439436</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PUBMED&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/25936269"><span id="translatedtitle">Rhubarb extract has a protective role against <span class="hlt">radiation-induced</span> brain injury and neuronal cell apoptosis.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lu, Kui; Zhang, Cheng; Wu, Wenjun; Zhou, Min; Tang, Yamei; Peng, Ying</p> <p>2015-08-01</p> <p>Oxidative stress caused by ionizing <span class="hlt">radiation</span> is involved in neuronal damage in a number of disorders, including trauma, stroke, Alzheimer's disease and amyotrophic lateral sclerosis. Ionizing <span class="hlt">radiation</span> can lead to the formation of free radicals, which cause neuronal apoptosis and have important roles in the development of some types of chronic brain disease. The present study evaluated the effects of varying concentrations (2, 5 and 10 µg/ml) of ethanolic rhubarb extract on the neuronal damage caused by irradiation in primary neuronal cultures obtained from the cortices of rat embryos aged 20 days. Brain damage was <span class="hlt">induced</span> with a single dose of ??irradiation that <span class="hlt">induced</span> DNA fragmentation, increased lactate dehydrogenase release in neuronal cells and acted as a trigger for microglial cell proliferation. Treatment with rhubarb extract significantly decreased <span class="hlt">radiation?induced</span> lactate dehydrogenase release and DNA fragmentation, which are important in the process of cell apoptosis. The rhubarb extract exhibited dose?dependent inhibition of lactate dehydrogenase release and neuronal cell apoptosis that were <span class="hlt">induced</span> by the administration of ionizing <span class="hlt">radiation</span>. The effect of a 10 µg/ml dose of rhubarb extract on the generation of reactive oxygen species (ROS) <span class="hlt">induced</span> by <span class="hlt">radiation</span> was also investigated. This dose led to significant inhibition of ROS generation. In conclusion, the present study showed a protective role of rhubarb extract against irradiation?<span class="hlt">induced</span> apoptotic neuronal cell death and ROS generation. PMID:25936269</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2010LaPhy..20.1500Z"><span id="translatedtitle">Effect of blue light <span class="hlt">radiation</span> on curcumin-<span class="hlt">induced</span> cell death of breast cancer cells</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zeng, X. B.; Leung, A. W. N.; Xia, X. S.; Yu, H. P.; Bai, D. Q.; Xiang, J. Y.; Jiang, Y.; Xu, C. S.</p> <p>2010-06-01</p> <p>In the present study, we have successfully set up a novel blue light source with the power density of 9 mW/cm2 and the wavelength of 435.8 nm and then the novel light source was used to investigate the effect of light <span class="hlt">radiation</span> on curcumin-<span class="hlt">induced</span> cell death. The cytotoxicity was investigated 24 h after the treatment of curcumin and blue light <span class="hlt">radiation</span> together using MTT reduction assay. Nuclear chromatin was observed using a fluorescent microscopy with Hoechst33258 staining. The results showed blue light <span class="hlt">radiation</span> could significantly enhance the cytotoxicity of curcumin on the MCF-7 cells and apoptosis induction. These findings demonstrated that blue light <span class="hlt">radiation</span> could enhance curcumin-<span class="hlt">induced</span> cell death of breast cancer cells, suggesting light <span class="hlt">radiation</span> may be an efficient enhancer of curcumin in the management of breast cancer.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASA-TRS&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20040087650&hterms=DNA&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DDNA"><span id="translatedtitle">Clustered DNA damages <span class="hlt">induced</span> in human hematopoietic cells by low doses of ionizing <span class="hlt">radiation</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sutherland, Betsy M.; Bennett, Paula V.; Cintron-Torres, Nela; Hada, Megumi; Trunk, John; Monteleone, Denise; Sutherland, John C.; Laval, Jacques; Stanislaus, Marisha; Gewirtz, Alan</p> <p>2002-01-01</p> <p>Ionizing <span class="hlt">radiation</span> <span class="hlt">induces</span> clusters of DNA damages--oxidized bases, abasic sites and strand breaks--on opposing strands within a few helical turns. Such damages have been postulated to be difficult to repair, as are double strand breaks (one type of cluster). We have shown that low doses of low and high linear energy transfer (LET) <span class="hlt">radiation</span> <span class="hlt">induce</span> such damage clusters in human cells. In human cells, DSB are about 30% of the total of complex damages, and the levels of DSBs and oxidized pyrimidine clusters are similar. The dose responses for cluster induction in cells can be described by a linear relationship, implying that even low doses of ionizing <span class="hlt">radiation</span> can produce clustered damages. Studies are in progress to determine whether clusters can be produced by mechanisms other than ionizing <span class="hlt">radiation</span>, as well as the levels of various cluster types formed by low and high LET <span class="hlt">radiation</span>.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PUBMED&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/17265150"><span id="translatedtitle">Protective effects of L-selenomethionine on space <span class="hlt">radiation</span> <span class="hlt">induced</span> changes in gene expression.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Stewart, J; Ko, Y-H; Kennedy, A R</p> <p>2007-06-01</p> <p>Ionizing <span class="hlt">radiation</span> can produce adverse biological effects in astronauts during space travel. Of particular concern are the types of <span class="hlt">radiation</span> from highly energetic, heavy, charged particles known as HZE particles. The aims of our studies are to characterize HZE particle <span class="hlt">radiation</span> <span class="hlt">induced</span> biological effects and evaluate the effects of L-selenomethionine (SeM) on these adverse biological effects. In this study, microarray technology was used to measure HZE <span class="hlt">radiation</span> <span class="hlt">induced</span> changes in gene expression, as well as to evaluate modulation of these changes by SeM. Human thyroid epithelial cells (HTori-3) were irradiated (1 GeV/n iron ions) in the presence or in the absence of 5 microM SeM. At 6 h post-irradiation, all cells were harvested for RNA isolation. Gene Chip U133Av2 from Affymetrix was used for the analysis of gene expression, and ANOVA and EASE were used for a determination of the genes and biological processes whose differential expression is statistically significant. Results of this microarray study indicate that exposure to small doses of <span class="hlt">radiation</span> from HZE particles, 10 and 20 cGy from iron ions, <span class="hlt">induces</span> statistically significant differential expression of 196 and 610 genes, respectively. In the presence of SeM, differential expression of 77 out of 196 genes (exposure to 10 cGy) and 336 out of 610 genes (exposure to 20 cGy) is abolished. In the presence or in the absence of SeM, <span class="hlt">radiation</span> from HZE particles <span class="hlt">induces</span> differential expression of genes whose products have roles in the induction of G1/S arrest during the mitotic cell cycle, as well as heat shock proteins. Some of the genes, whose expressions were affected by <span class="hlt">radiation</span> from HZE particles and were unchanged in irradiated cells treated with SeM, have been shown to have altered expression levels in cancer cells. The conclusions of this report are that <span class="hlt">radiation</span> from HZE particles can <span class="hlt">induce</span> differential expression of many genes, some of which are known to play roles in the same processes that have been shown to be activated in cells exposed to <span class="hlt">radiation</span> from photons (like cell cycle arrest in G1/S), and that supplementation with SeM abolishes HZE particle-<span class="hlt">induced</span> differential expression of many genes. Understanding the roles that these genes play in the <span class="hlt">radiation-induced</span> transformation of cells may help to decipher the origins of <span class="hlt">radiation-induced</span> cancer. PMID:17265150</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/22218239"><span id="translatedtitle">Surface photoconductivity of organosilicate glass dielectrics <span class="hlt">induced</span> by vacuum-ultraviolet <span class="hlt">radiation</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Zheng, H.; Nichols, M. T.; Pei, D.; Shohet, J. L. [Plasma Processing and Technology Laboratory and Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)] [Plasma Processing and Technology Laboratory and Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); Nishi, Y. [Department of Electrical Engineering, Stanford University, Stanford, CA 94305 (United States)] [Department of Electrical Engineering, Stanford University, Stanford, CA 94305 (United States)</p> <p>2013-08-14</p> <p>The temporary increase in the electrical surface conductivity of low-k organosilicate glass (SiCOH) during exposure to vacuum-ultraviolet <span class="hlt">radiation</span> (VUV) is investigated. To measure the photoconductivity, patterned “comb structures” are deposited on dielectric films and exposed to synchrotron <span class="hlt">radiation</span> in the range of 8–25 eV, which is in the energy range of most plasma vacuum-ultraviolet <span class="hlt">radiation</span>. The change in photo surface conductivity <span class="hlt">induced</span> by VUV <span class="hlt">radiation</span> may be beneficial in limiting charging damage of dielectrics by depleting the plasma-deposited charge.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/23339821"><span id="translatedtitle"><span class="hlt">Radiation-induced</span> degradation of carboxymethylated chitosan in aqueous solution</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Ling Huang; Maolin Zhai; Jing Peng; Jiuqiang Li; Genshuan Wei</p> <p>2007-01-01</p> <p>Aqueous solutions of carboxymethylated chitosan (CM-chitosan) were <span class="hlt">radiated</span> with ?-ray in various conditions. The degradations of CM-chitosan were faster in the presence of nitrous oxide or hydrogen peroxide, but it was inhibited obviously after adding isopropanol because of the changes of the concentration of hydroxyl radicals in above different conditions. The <span class="hlt">radiation</span> chemical yields of CM-chitosan degradation were found to</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://www.fasebj.org/cgi/reprint/15/1/123.pdf"><span id="translatedtitle">Activation of a nuclear sphingomyelinase in <span class="hlt">radiation-induced</span> apoptosis</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>JEAN-PIERRE JAFFREZOU; ALAIN P. BRUNO; THIERRY LEVADE; GUY LAURENT</p> <p>2001-01-01</p> <p>The subcellular origin of ceramide sig- naling in ionizing <span class="hlt">radiation</span>-triggered apoptosis was investigated using two previously described subclones of the autonomous erythro-myeloblastic cell line TF-1, radio-resistant and -sensitive TF-1-34 and TF-1-33, respectively. We show in nuclei-free lysates and cyto- plasts that both cell lines failed to generate ceramide in response to ionizing <span class="hlt">radiation</span>. Moreover, whereas cy- toplasts did respond to</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PUBMED&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/20848992"><span id="translatedtitle">Radioprotection from <span class="hlt">radiation-induced</span> lymphedema without tumor protection.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Daley, S K; Bernas, M J; Stea, B D; Bracamonte, F; McKenna, M; Stejskal, A; Hirleman, E D; Witte, M H</p> <p>2010-06-01</p> <p>Lymphedema or tissue swelling from impaired lymph drainage commonly occurs after regional nodal dissection and/or <span class="hlt">radiation</span> therapy for cancer control. Treatment options for this disabling and life-altering complication involve long-term labor-intensive commitments. Sentinel node biopsy can forestall removal of negative regional nodes, offering some protection against lymphedema, however, most preventive measures are elusive, ineffective, or unproven. Our goal was to determine whether the radioprotectant amifostine could prevent or retard the development of lymphedema in a rodent <span class="hlt">radiation</span> therapy-dependent model yet not offer tumor protection from the therapeutic effects of <span class="hlt">radiation</span> therapy. We pre-treated rats after unilateral radical groin dissection with the organic thiophosphate radioprotectant amifostine or placebo prior to single dose post-operative groin <span class="hlt">radiation</span> therapy and monitored hindlimb volumes, wound scores, and tissue lymphostasis. In addition, we determined whether amifostine protected human MCF7 breast cancer cells exposed to a range of <span class="hlt">radiation</span> therapy doses in an in vitro clonogenic assay and an in vivo MCF7 tumor xenograft model. Our findings indicate that amifostine markedly reduced the volume of limb lymphedema and dramatically improved wound healing and tissue lymphostasis in the rodent lymphedema model. The in vivo and in vitro studies further demonstrated that amifostine offered no MCF7 tumor protection from <span class="hlt">radiation</span> therapy. These pre-clinical findings provide proof-of-principle to further delineate specific mechanisms underlying amifostine's beneficial effects, determine optimal amifostine-<span class="hlt">radiation</span> therapy dosing regimens, and thereby expedite translation into clinical trials to reduce lymphedema incidence and severity in cancer patients at high lymphedema risk in whom <span class="hlt">radiation</span> therapy is the recommended therapy. PMID:20848992</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/50369650"><span id="translatedtitle">Near THz <span class="hlt">radiation</span> from optically-<span class="hlt">induced</span> plasma sources</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>F. J. Zutavern; J. V. Rudd; L. A. Mcpherson; T. R. Nelson; T. S. Luk; S. M. Cameron</p> <p>2004-01-01</p> <p>Summary form only given. Short pulse lasers can be used to generate two types of short-lived, <span class="hlt">radiating</span> plasmas. When absorbed by a semiconductor, a sudden optical pulse creates a charge-neutral, electron-hole plasma that <span class="hlt">radiates</span> as the carriers relax in local crystal, surface, or applied electric fields. When focused onto the surface of an insulator or metal, the electric fields in</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/19272935"><span id="translatedtitle">Gamma <span class="hlt">Radiation</span> <span class="hlt">Induced</span> Degradation of Operating Quantum Dot Lasers</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>J. W. Mares; J. Harben; A. V. Thompson; D. W. Schoenfeld; W. V. Schoenfeld</p> <p>2008-01-01</p> <p>The degradation of quantum dot lasers (QDLs) due to 1.17 and 1.22 MeV gamma <span class="hlt">radiation</span> is characterized by changes in threshold current, external slope efficiency and light output. Both operating and non-operating lasers were exposed to a Co-60 source, providing gamma <span class="hlt">radiation</span> at a dose rate of 0.4 kGy\\/hr to a total absorbed dose of 1.6 MGy. Degradation rates of</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2012RaPC...81.1361M"><span id="translatedtitle">The influence of the initial preparation and <span class="hlt">crystallinity</span> on the free radical evolution in gamma irradiated PLLA</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Milicevic, D.; Milivojevic, D.; Suljovrujic, E.</p> <p>2012-09-01</p> <p>Poly-L-lactide (PLLA) is a well-known biodegradable and biocompatible semi-<span class="hlt">crystalline</span> polymer, used in a wide variety of applications, from implantable medical devices and drug release matrices to environmentally friendly packaging materials; diversity in the initial preparation, morphology and <span class="hlt">crystallinity</span> plays a significant role in most of these applications. On the other hand, gamma <span class="hlt">radiation</span>, as a processing tool, has often been used for the sterilisation of sensitive polymeric materials. This study presents the influence of the initial preparation and <span class="hlt">crystallinity</span> on the gamma <span class="hlt">radiation-induced</span> evolution of free radicals in PLLA. For this purpose, PLLA samples with a large variation in <span class="hlt">crystallinity</span> (below 20% and over 70%), prepared by two different procedures, were exposed to gamma <span class="hlt">radiation</span> in air to absorbed doses of 25, 50 and 100 kGy. The annealing treatment was applied to part of the samples, too. The presence and evolution of free radicals were followed using electron spin resonance (ESR) spectroscopy for three weeks. Further characterisation was performed by scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and wide angle X-ray diffraction (WAXD) measurements. Presented results show that depending on the initial preparation conditions, the <span class="hlt">radiation-induced</span> changes in structure and properties of PLLA, as well as the evolution of free radicals, can differ significantly. Furthermore, the annealing treatment substantially reduces the concentration of long-lived free radicals, but can also introduce significant crystallisation.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://www.ece.rice.edu/~kono/CerneetAl97APL.pdf"><span id="translatedtitle">Near-infrared sideband generation <span class="hlt">induced</span> by intense far-infrared <span class="hlt">radiation</span> in GaAs quantum wells</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Kono, Junichiro</p> <p></p> <p>Near-infrared sideband generation <span class="hlt">induced</span> by intense far-infrared <span class="hlt">radiation</span> in GaAs quantum wells J illuminated with near-infrared NIR <span class="hlt">radiation</span> at frequency nir and intense far-infrared FIR <span class="hlt">radiation</span> from and quenching of photoluminescence PL .8,9 The nonlinear interaction of FIR and near-infrared NIR <span class="hlt">radiation</span></p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PUBMED&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/24828078"><span id="translatedtitle">PHD inhibition mitigates and protects against <span class="hlt">radiation-induced</span> gastrointestinal toxicity via HIF2.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Taniguchi, Cullen M; Miao, Yu Rebecca; Diep, Anh N; Wu, Colleen; Rankin, Erinn B; Atwood, Todd F; Xing, Lei; Giaccia, Amato J</p> <p>2014-05-14</p> <p><span class="hlt">Radiation-induced</span> gastrointestinal (GI) toxicity can be a major source of morbidity and mortality after <span class="hlt">radiation</span> exposure. There is an unmet need for effective preventative or mitigative treatments against the potentially fatal diarrhea and water loss <span class="hlt">induced</span> by <span class="hlt">radiation</span> damage to the GI tract. We report that prolyl hydroxylase inhibition by genetic knockout or pharmacologic inhibition of all PHD (prolyl hydroxylase domain) isoforms by the small-molecule dimethyloxallyl glycine (DMOG) increases hypoxia-<span class="hlt">inducible</span> factor (HIF) expression, improves epithelial integrity, reduces apoptosis, and increases intestinal angiogenesis, all of which are essential for radioprotection. HIF2, but not HIF1, is both necessary and sufficient to prevent <span class="hlt">radiation-induced</span> GI toxicity and death. Increased vascular endothelial growth factor (VEGF) expression contributes to the protective effects of HIF2, because inhibition of VEGF function reversed the radioprotection and radiomitigation afforded by DMOG. Additionally, mortality from abdominal or total body irradiation was reduced even when DMOG was given 24 hours after exposure. Thus, prolyl hydroxylase inhibition represents a treatment strategy to protect against and mitigate GI toxicity from both therapeutic <span class="hlt">radiation</span> and potentially lethal <span class="hlt">radiation</span> exposures. PMID:24828078</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASA-TRS&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20130013689&hterms=Oncogene&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3DOncogene"><span id="translatedtitle">Chromatin Folding, Fragile Sites, and Chromosome Aberrations <span class="hlt">Induced</span> by Low- and High- LET <span class="hlt">Radiation</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Zhang, Ye; Cox, Bradley; Asaithamby, Aroumougame; Chen, David J.; Wu, Honglu</p> <p>2013-01-01</p> <p>We previously demonstrated non-random distributions of breaks involved in chromosome aberrations <span class="hlt">induced</span> by low- and high-LET <span class="hlt">radiation</span>. To investigate the factors contributing to the break point distribution in <span class="hlt">radiation-induced</span> chromosome aberrations, human epithelial cells were fixed in G1 phase. Interphase chromosomes were hybridized with a multicolor banding in situ hybridization (mBAND) probe for chromosome 3 which distinguishes six regions of the chromosome in separate colors. After the images were captured with a laser scanning confocal microscope, the 3-dimensional structure of interphase chromosome 3 was reconstructed at multimega base pair scale. Specific locations of the chromosome, in interphase, were also analyzed with bacterial artificial chromosome (BAC) probes. Both mBAND and BAC studies revealed non-random folding of chromatin in interphase, and suggested association of interphase chromatin folding to the <span class="hlt">radiation-induced</span> chromosome aberration hotspots. We further investigated the distribution of genes, as well as the distribution of breaks found in tumor cells. Comparisons of these distributions to the <span class="hlt">radiation</span> hotspots showed that some of the <span class="hlt">radiation</span> hotspots coincide with the frequent breaks found in solid tumors and with the fragile sites for other environmental toxins. Our results suggest that multiple factors, including the chromatin structure and the gene distribution, can contribute to <span class="hlt">radiation-induced</span> chromosome aberrations.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PUBMED&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/25072018"><span id="translatedtitle">Mitochondria regulate DNA damage and genomic instability <span class="hlt">induced</span> by high LET <span class="hlt">radiation</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhang, Bo; Davidson, Mercy M; Hei, Tom K</p> <p>2014-04-01</p> <p>High linear energy transfer (LET) <span class="hlt">radiation</span> including ? particles and heavy ions is the major type of <span class="hlt">radiation</span> find in space and is considered a potential health risk for astronauts. Even though the chance that these high LET particles traversing through the cytoplasm of cells is higher than that through the nuclei, the contribution of targeted cytoplasmic irradiation, to the induction of genomic instability and other chromosomal damages <span class="hlt">induced</span> by high LET <span class="hlt">radiation</span> is not known. In the present study, we investigated whether mitochondria are the potential cytoplasmic target of high LET <span class="hlt">radiation</span> in mediating cellular damage using a mitochondrial DNA (mtDNA) depleted (?(0)) human small airway epithelial (SAE) cell model and a precision charged particle microbeam with a beam width of merely one micron. Targeted cytoplasmic irradiation by high LET ? particles <span class="hlt">induced</span> DNA oxidative damage and double strand breaks in wild type ?(+) SAE cells. Furthermore, there was a significant increase in autophagy, micronuclei, which is an indication of genomic instability, together with the activation of nuclear factor kappa-B (NF-?B) and mitochondrial <span class="hlt">inducible</span> nitric oxide synthase (iNOS) signaling pathways in ?(+) SAE cells. In contrast, ?(0) SAE cells exhibited a significantly lower response to these same endpoints examined after cytoplasmic irradiation with high LET ? particles. The results indicate that mitochondria are essential in mediating cytoplasmic <span class="hlt">radiation</span> <span class="hlt">induced</span> genotoxic damage in mammalian cells. Furthermore, the findings may shed some light in the design of countermeasures for space <span class="hlt">radiation</span>. PMID:25072018</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PMC&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4111269"><span id="translatedtitle">Mitochondria regulate DNA damage and genomic instability <span class="hlt">induced</span> by high LET <span class="hlt">radiation</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Zhang, Bo; Davidson, Mercy M.; Hei, Tom K.</p> <p>2014-01-01</p> <p>High linear energy transfer (LET) <span class="hlt">radiation</span> including ? particles and heavy ions is the major type of <span class="hlt">radiation</span> find in space and is considered a potential health risk for astronauts. Even though the chance that these high LET particles traversing through the cytoplasm of cells is higher than that through the nuclei, the contribution of targeted cytoplasmic irradiation, to the induction of genomic instability and other chromosomal damages <span class="hlt">induced</span> by high LET <span class="hlt">radiation</span> is not known. In the present study, we investigated whether mitochondria are the potential cytoplasmic target of high LET <span class="hlt">radiation</span> in mediating cellular damage using a mitochondrial DNA (mtDNA) depleted (?0) human small airway epithelial (SAE) cell model and a precision charged particle microbeam with a beam width of merely one micron. Targeted cytoplasmic irradiation by high LET ? particles <span class="hlt">induced</span> DNA oxidative damage and double strand breaks in wild type ?+ SAE cells. Furthermore, there was a significant increase in autophagy, micronuclei, which is an indication of genomic instability, together with the activation of nuclear factor kappa-B (NF-?B) and mitochondrial <span class="hlt">inducible</span> nitric oxide synthase (iNOS) signaling pathways in ?+ SAE cells. In contrast, ?0 SAE cells exhibited a significantly lower response to these same endpoints examined after cytoplasmic irradiation with high LET ? particles. The results indicate that mitochondria are essential in mediating cytoplasmic <span class="hlt">radiation</span> <span class="hlt">induced</span> genotoxic damage in mammalian cells. Furthermore, the findings may shed some light in the design of countermeasures for space <span class="hlt">radiation</span>. PMID:25072018</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/134861"><span id="translatedtitle">Biological responses of human apurinic endonuclease to <span class="hlt">radiation-induced</span> DNA damage</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Chen, D.S.; Olkowski, Z.L. [Emory Univ. School of Medicine, Atlanta, GA (United States)</p> <p>1994-12-31</p> <p>Ionizing <span class="hlt">radiation</span> produces a variety of DNA damage through active oxygen species such as the superoxide radical (O{sub 2}{sup -}), the hydroxyl radical (OH), and hydrogen peroxide (H{sub 2}O{sub 2}). Previous studies showed that human AP endonuclease, a counterpart of exonuclease III, can functionally replace E. coli exonuclease III to repair methyl methanesulfonate (MMS)-<span class="hlt">induced</span> but not H{sub 2}O{sub 2}-<span class="hlt">induced</span> DNA damage. Reduction of <span class="hlt">radiation-induced</span> cytotoxicity by human AP endonuclease in a <span class="hlt">radiation</span>-sensitive mutant of E. coli indicated that the AP site is one of the major forms of DNA damage produced by ionizing <span class="hlt">radiation</span>. The removal of alkylation-<span class="hlt">induced</span> AP sites and 3{prime}-blocking deoxyribose fragments by human AP endonuclease indicates that this enzyme is playing a pivotal role in the repair of oxidative DNA damage. In the current study, we examined the biological roles of AP endonuclease as being responsible for the repair of <span class="hlt">radiation-induced</span> DNA damage in human cells.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PUBMED&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/25770423"><span id="translatedtitle">Activating PTEN by COX-2 inhibitors antagonizes <span class="hlt">radiation-induced</span> AKT activation contributing to radiosensitization.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Meng, Zhen; Gan, Ye-Hua</p> <p>2015-05-01</p> <p>Radiotherapy is still one of the most effective nonsurgical treatments for many tumors. However, radioresistance remains a major impediment to radiotherapy. Although COX-2 inhibitors can <span class="hlt">induce</span> radiosensitization, the underlying mechanism is not fully understood. In this study, we showed that COX-2 selective inhibitor celecoxib enhanced the <span class="hlt">radiation-induced</span> inhibition of cell proliferation and apoptosis in HeLa and SACC-83 cells. Treatment with celecoxib alone dephosphorylated phosphatase and tensin homolog deleted on chromosome ten (PTEN), promoted PTEN membrane translocation or activation, and correspondingly dephosphorylated or inactivated protein kinase B (AKT). By contrast, treatment with <span class="hlt">radiation</span> alone increased PTEN phosphorylation, inhibited PTEN membrane translocation and correspondingly activated AKT in the two cell lines. However, treatment with celecoxib or another COX-2 selective inhibitor (valdecoxib) completely blocked <span class="hlt">radiation-induced</span> increase of PTEN phosphorylation, rescued <span class="hlt">radiation-induced</span> decrease in PTEN membrane translocation, and correspondingly inactivated AKT. Moreover, celecoxib could also upregulate PTEN protein expression by downregulating Sp1 expression, thereby leading to the activation of PTEN transcription. Our results suggested that COX-2 inhibitors could enhance radiosensitization at least partially by activating PTEN to antagonize <span class="hlt">radiation-induced</span> AKT activation. PMID:25770423</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PUBMED&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/24854039"><span id="translatedtitle">Role of ferulic acid in the amelioration of ionizing <span class="hlt">radiation</span> <span class="hlt">induced</span> inflammation: a murine model.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Das, Ujjal; Manna, Krishnendu; Sinha, Mahuya; Datta, Sanjukta; Das, Dipesh Kr; Chakraborty, Anindita; Ghosh, Mahua; Saha, Krishna Das; Dey, Sanjit</p> <p>2014-01-01</p> <p>Ionizing <span class="hlt">radiation</span> is responsible for oxidative stress by generating reactive oxygen species (ROS), which alters the cellular redox potential. This change activates several redox sensitive enzymes which are crucial in activating signaling pathways at molecular level and can lead to oxidative stress <span class="hlt">induced</span> inflammation. Therefore, the present study was intended to assess the anti-inflammatory role of ferulic acid (FA), a plant flavonoid, against <span class="hlt">radiation-induced</span> oxidative stress with a novel mechanistic viewpoint. FA was administered (50 mg/kg body wt) to Swiss albino mice for five consecutive days prior to exposing them to a single dose of 10 Gy 60Co ?-irradiation. The dose of FA was optimized from the survival experiment and 50 mg/kg body wt dose showed optimum effect. FA significantly ameliorated the <span class="hlt">radiation</span> <span class="hlt">induced</span> inflammatory response such as phosphorylation of IKK?/? and I?B? and consequent nuclear translocation of nuclear factor kappa B (NF-?B). FA also prevented the increase of cycloxygenase-2 (Cox-2) protein, <span class="hlt">inducible</span> nitric oxide synthase-2 (iNOS-2) gene expression, lipid peroxidation in liver and the increase of tumor necrosis factor-alpha (TNF-?) and interleukin-6 (IL-6) in serum. It was observed that exposure to <span class="hlt">radiation</span> results in decreased activity of superoxide dismutase (SOD), catalase (CAT) and the pool of reduced glutathione (GSH) content. However, FA treatment prior to irradiation increased the activities of the same endogenous antioxidants. Thus, pretreatment with FA offers protection against gamma <span class="hlt">radiation</span> <span class="hlt">induced</span> inflammation. PMID:24854039</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASA-TRS&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19920004637&hterms=Fast+Food+Health&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DFast%2BFood%2BHealth"><span id="translatedtitle">Naturally <span class="hlt">induced</span> secondary <span class="hlt">radiation</span> in interplanetary space: Preliminary analyses for gamma <span class="hlt">radiation</span> and radioisotope production from thermal neutron activation</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Plaza-Rosado, Heriberto</p> <p>1991-01-01</p> <p>Thermal neutron activation analyses were carried out for various space systems components to determine gamma <span class="hlt">radiation</span> dose rates and food <span class="hlt">radiation</span> contamination levels. The space systems components selected were those for which previous <span class="hlt">radiation</span> studies existed. These include manned space vehicle <span class="hlt">radiation</span> shielding, liquid hydrogen propellant tanks for a Mars mission, and a food supply used as space vehicle <span class="hlt">radiation</span> shielding. The computational method used is based on the fast neutron distribution generated by the BRYNTRN and HZETRN transport codes for Galactic Cosmic Rays (GCR) at solar minimum conditions and intense solar flares in space systems components. The gamma dose rates for soft tissue are calculated for water and aluminum space vehicle slab shields considering volumetric source self-attenuation and exponential buildup factors. In the case of the lunar habitat with regolith shielding, a completely exposed spherical habitat was assumed for mathematical convenience and conservative calculations. Activation analysis of the food supply used as <span class="hlt">radiation</span> shielding is presented for four selected nutrients: potassium, calcium, sodium, and phosphorus. Radioactive isotopes that could represent a health hazard if ingested are identified and their concentrations are identified. For nutrients soluble in water, it was found that all <span class="hlt">induced</span> radioactivity was below the accepted maximum permissible concentrations.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/1991asee.nasa..181P"><span id="translatedtitle">Naturally <span class="hlt">induced</span> secondary <span class="hlt">radiation</span> in interplanetary space: Preliminary analyses for gamma <span class="hlt">radiation</span> and radioisotope production from thermal neutron activation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Plaza-Rosado, Heriberto</p> <p>1991-09-01</p> <p>Thermal neutron activation analyses were carried out for various space systems components to determine gamma <span class="hlt">radiation</span> dose rates and food <span class="hlt">radiation</span> contamination levels. The space systems components selected were those for which previous <span class="hlt">radiation</span> studies existed. These include manned space vehicle <span class="hlt">radiation</span> shielding, liquid hydrogen propellant tanks for a Mars mission, and a food supply used as space vehicle <span class="hlt">radiation</span> shielding. The computational method used is based on the fast neutron distribution generated by the BRYNTRN and HZETRN transport codes for Galactic Cosmic Rays (GCR) at solar minimum conditions and intense solar flares in space systems components. The gamma dose rates for soft tissue are calculated for water and aluminum space vehicle slab shields considering volumetric source self-attenuation and exponential buildup factors. In the case of the lunar habitat with regolith shielding, a completely exposed spherical habitat was assumed for mathematical convenience and conservative calculations. Activation analysis of the food supply used as <span class="hlt">radiation</span> shielding is presented for four selected nutrients: potassium, calcium, sodium, and phosphorus. Radioactive isotopes that could represent a health hazard if ingested are identified and their concentrations are identified. For nutrients soluble in water, it was found that all <span class="hlt">induced</span> radioactivity was below the accepted maximum permissible concentrations.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASA-TRS&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20040112612&hterms=erythrocyte&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Derythrocyte"><span id="translatedtitle">Impact of p53 status on heavy-ion <span class="hlt">radiation-induced</span> micronuclei in circulating erythrocytes</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Chang, P. Y.; Torous, D.; Lutze-Mann, L.; Winegar, R.</p> <p>2000-01-01</p> <p>Transgenic mice that differed in their p53 genetic status were exposed to an acute dose of highly charged and energetic (HZE) iron particle <span class="hlt">radiation</span>. Micronuclei (MN) in two distinct populations of circulating peripheral blood erythrocytes, the immature reticulocytes (RETs) and the mature normochromatic erythrocytes (NCEs), were measured using a simple and efficient flow cytometric procedure. Our results show significant elevation in the frequency of micronucleated RETs (%MN-RETs) at 2 and 3 days post-<span class="hlt">radiation</span>. At 3 days post-irradiation, the magnitude of the <span class="hlt">radiation-induced</span> MN-RET was 2.3-fold higher in the irradiated p53 wild-type animals compared to the unirradiated controls, 2.5-fold higher in the p53 hemizygotes and 4.3-fold higher in the p53 nullizygotes. The persistence of this <span class="hlt">radiation-induced</span> elevation of MN-RETs is dependent on the p53 genetic background of the animal. In the p53 wild-type and p53 hemizygotes, %MN-RETs returned to control levels by 9 days post-<span class="hlt">radiation</span>. However, elevated levels of %MN-RETs in p53 nullizygous mice persisted beyond 56 days post-<span class="hlt">radiation</span>. We also observed elevated MN-NCEs in the peripheral circulation after <span class="hlt">radiation</span>, but the changes in <span class="hlt">radiation-induced</span> levels of MN-NCEs appear dampened compared to those of the MN-RETs for all three strains of animals. These results suggest that the lack of p53 gene function may play a role in the iron particle <span class="hlt">radiation-induced</span> genomic instability in stem cell populations in the hematopoietic system.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/60293829"><span id="translatedtitle">Relationship between the repair of <span class="hlt">radiation-induced</span> DNA damage and recovery from potentially lethal damage in 9L rat brain tumor cells. [Gamma <span class="hlt">radiation</span></span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>S. C. vanAnkeren; K. T. Wheeler</p> <p>1984-01-01</p> <p>The kinetics of repair of <span class="hlt">radiation-induced</span> DNA damage and recovery from <span class="hlt">radiation-induced</span> potentially lethal damage (PLD) for fed plateau-phase 9L\\/Ro rat brain tumor cells were compared after single doses of gamma-<span class="hlt">radiation</span> and after combined treatment with 3 micrograms of 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU)\\/ml given 16 hr prior to irradiation. DNA damage and repair were assayed using alkaline filter elution, while cell survival</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PUBMED&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/24792319"><span id="translatedtitle">Complementary and alternative medicine in reducing <span class="hlt">radiation-induced</span> skin toxicity.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hu, Jennifer J; Cui, Tengjiao; Rodriguez-Gil, Jorge L; Allen, Glenn O; Li, Jie; Takita, Cristiane; Lally, Brian E</p> <p>2014-08-01</p> <p><span class="hlt">Radiation</span> therapy-<span class="hlt">induced</span> acute and late effects, particularly skin toxicities, have significant impact on cancer patients' quality of life and long-term survival. To date, no effective topical agents have been routinely used in the clinical setting to prevent skin toxicity. Using SKH-hr1 hairless mice, we investigated two complementary and alternative medicine in their effects on inflammation and ionizing <span class="hlt">radiation</span> (IR)-<span class="hlt">induced</span> skin toxicity: Calendula officinalis (CO) and Ching Wan Hung (CWH). They were applied immediately following each IR dosing of 10 Gy/day for 4 days. Skin toxicity and inflammatory factors were evaluated at multiple time points up to 15 days post-<span class="hlt">radiation</span>. Serum interleukin (IL)-1?, monocyte chemotactic protein-1 (MCP1), keratinocyte-derived chemokine (KC), and granulocyte colony-stimulating factor (G-CSF) were significantly <span class="hlt">induced</span> by <span class="hlt">radiation</span>. Both CO and CWH significantly inhibited IR-<span class="hlt">induced</span> MCP1 (p < 0.01), KC (p < 0.05), and G-CSF (p < 0.001). IR-<span class="hlt">induced</span> erythema and blood vessel dilation were significantly reduced by CWH (p < 0.001) but not by CO at day 10 post-IR. Both agents inhibited IR-<span class="hlt">induced</span> IL-1? (p < 0.01), MCP1 (p < 0.05), and vascular endothelial growth factor (p < 0.05). There were continuous inhibitory effects of CWH on IR-<span class="hlt">induced</span> skin toxicities and inflammation. In contrast, CO treatment resulted in skin reactions compared to IR alone. Our results suggest that both CO and CWH reduce IR-<span class="hlt">induced</span> inflammation and CWH reduced IR-<span class="hlt">induced</span> erythema. In summary, CWH showed promising effects in reducing IR-related inflammation and skin toxicities, and future proof-of-principal testing in humans will be critical in evaluating its potential application in preventing IR-<span class="hlt">induced</span> skin toxicities. PMID:24792319</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2009PhRvB..79c3406R"><span id="translatedtitle">Thermal-<span class="hlt">radiation-induced</span> nonequilibrium carriers in intrinsic graphene</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Romanets, P. N.; Vasko, F. T.; Strikha, M. V.</p> <p>2009-01-01</p> <p>We have examined an intrinsic graphene connected to the phonon thermostat at temperature T under irradiation of thermal photons with temperature Tr , different from T . The distribution of nonequilibrium electron-hole pairs was obtained for the cases when the interparticle scattering is unessential and when the Coulomb scattering dominates. For the first case, the distribution function is determined by the interplay of intraband relaxation of energy due to acoustic phonons and interband <span class="hlt">radiative</span> transitions caused by the thermal <span class="hlt">radiation</span>. For the alter case, the quasiequilibrium distribution with effective temperature and nonequilibrium concentration, determined through balance equations, is realized. Due to the effect of thermal <span class="hlt">radiation</span> with temperature Tr?T , concentration and conductivity of carriers in graphene are modified essentially. It is demonstrated that at Tr>T , the negative interband absorption caused by the inversion of carriers distribution can occur.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/35368840"><span id="translatedtitle">Inhibitory effect of folinic acid on <span class="hlt">radiation-induced</span> micronuclei and chromosomal aberrations in V79 cells</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>C. Keshava; R. Nagalakshmi; T. Ong; J. Nath</p> <p>1996-01-01</p> <p>Folinic acid (FA), clinically called leucovorin, has been widely used as a nutrient supplement in dietary intake and is capable of inhibiting cytotoxicity and chromosomal damage <span class="hlt">induced</span> by chemicals. However, data on its antigenotoxic effect on <span class="hlt">radiation-induced</span> chromosomal damage are limited. The present study was, therefore, performed to investigate the effect of FA on <span class="hlt">radiation-induced</span> (X-rays and UV <span class="hlt">radiation</span>) micronuclei</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PUBMED&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/24684069"><span id="translatedtitle">[Tanning lamp <span class="hlt">radiation-induced</span> photochemical retinal damage].</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Volkov, V V; Kharitonova, N N; Mal'tsev, D S</p> <p>2014-01-01</p> <p>On the basis of original clinical research a rare case of bilateral retinal damage due to tanning lamp <span class="hlt">radiation</span> exposure is presented. Along with significant decrease of visual acuity and light sensitivity of central visual field as well as color vision impairment, bilateral macular dystrophy was found during an ophthalmoscopy and confirmed by optical coherent tomography and fluorescent angiography. Intensive retinoprotective, vascular, and antioxidant therapy was effective and led to functional improvement and stabilization of the pathologic process associated with photochemical retinal damage. A brief review of literature compares mechanisms of retinal damage by either short or long-wave near visible <span class="hlt">radiation</span>. PMID:24684069</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://arxiv.org/pdf/1503.02609.pdf"><span id="translatedtitle">Heavy ion irradiation of <span class="hlt">crystalline</span> water ice</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Dartois, E; Boduch, P; Brunetto, R; Chabot, M; Domaracka, A; Ding, J J; Kamalou, O; Lv, X Y; Rothard, H; da Silveira, E F; Thomas, J C</p> <p>2015-01-01</p> <p>Under cosmic irradiation, the interstellar water ice mantles evolve towards a compact amorphous state. <span class="hlt">Crystalline</span> ice amorphisation was previously monitored mainly in the keV to hundreds of keV ion energies. We experimentally investigate heavy ion irradiation amorphisation of <span class="hlt">crystalline</span> ice, at high energies closer to true cosmic rays, and explore the water-ice sputtering yield. We irradiated thin <span class="hlt">crystalline</span> ice films with MeV to GeV swift ion beams, produced at the GANIL accelerator. The ice infrared spectral evolution as a function of fluence is monitored with in-situ infrared spectroscopy (<span class="hlt">induced</span> amorphisation of the initial <span class="hlt">crystalline</span> state into a compact amorphous phase). The <span class="hlt">crystalline</span> ice amorphisation cross-section is measured in the high electronic stopping-power range for different temperatures. At large fluence, the ice sputtering is measured on the infrared spectra, and the fitted sputtering-yield dependence, combined with previous measurements, is quadratic over three decades of electronic ...</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PMC&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3395590"><span id="translatedtitle">Spatially Fractionated <span class="hlt">Radiation</span> <span class="hlt">Induces</span> Cytotoxicity and Changes in Gene Expression in Bystander and <span class="hlt">Radiation</span> Adjacent Murine Carcinoma Cells</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Asur, Rajalakshmi S.; Sharma, Sunil; Chang, Ching-Wei; Penagaricano, Jose; Kommuru, Indira M.; Moros, Eduardo G.; Corry, Peter M.; Griffin, Robert J.</p> <p>2012-01-01</p> <p><span class="hlt">Radiation-induced</span> bystander effects have been extensively studied at low doses, since evidence of bystander <span class="hlt">induced</span> cell killing and other effects on unirradiated cells were found to be predominant at doses up to 0.5 Gy. Therefore, few studies have examined bystander effects <span class="hlt">induced</span> by exposure to higher doses of <span class="hlt">radiation</span>, such as spatially fractionated <span class="hlt">radiation</span> (GRID) treatment. In the present study, we evaluate the ability of GRID treatment to <span class="hlt">induce</span> changes in GRID adjacent (bystander) regions, in two different murine carcinoma cell lines following exposure to a single irradiation dose of 10 Gy. Murine SCK mammary carcinoma cells and SCCVII squamous carcinoma cells were irradiated using a brass collimator to create a GRID pattern of nine circular fields 12 mm in diameter with a center-to-center distance of 18 mm. Similar to the typical clinical implementation of GRID, this is approximately a 50:50 ratio of direct and bystander exposure. We also performed experiments by irradiating separate cultures and transferring the medium to unirradiated bystander cultures. Clonogenic survival was evaluated in both cell lines to determine the occurrence of <span class="hlt">radiation-induced</span> bystander effects. For the purpose of our study, we have defined bystander cells as GRID adjacent cells that received approximately 1 Gy scatter dose or unirradiated cells receiving conditioned medium from irradiated cells. We observed significant bystander killing of cells adjacent to the GRID irradiated regions compared to sham treated controls. We also observed bystander killing of SCK and SCCVII cells cultured in conditioned medium obtained from cells irradiated with 10 Gy. Therefore, our results confirm the occurrence of bystander effects following exposure to a high-dose of <span class="hlt">radiation</span> and suggest that cell-to-cell contact is not required for these effects. In addition, the gene expression profile for DNA damage and cellular stress response signaling in SCCVII cells after GRID exposure was studied. The occurrence of GRID-<span class="hlt">induced</span> bystander gene expression changes in significant numbers of DNA damage and cellular stress response signaling genes, providing molecular evidence for possible mechanisms of bystander cell killing. PMID:22559204</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/servlets/purl/924961"><span id="translatedtitle"><span class="hlt">Radiation</span> <span class="hlt">Induced</span> Stress Relaxation in Silicone and Polyurethane Elastomers</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Spellman, G; Gourdin, W; Jensen, W; Pearson, M; Fine, I</p> <p>2007-08-22</p> <p>Many different materials are used in the National Ignition Facility, NIF, located at Lawrence Livermore National Laboratory, LLNL. Some of these are exposed to significant doses of ionizing <span class="hlt">radiation</span>. Two elastomers are of special interest because they are used in sealing applications with long expected lifetimes. These are LPU4, a polyurethane formulated at LLNL, and Dow Corning DC93-500, a silicone RTV elastomer. In 2004 a program to determine the impact of ionizing <span class="hlt">radiation</span> on the stress relaxation and compression set characteristics of these two elastomers was undertaken. Since the materials are used in continuous compression and must reliably seal, the primary test utilized was a stress relaxation test. This test provides insight into the ability of a seal to remain functional in a static seal. The test determines how much residual force remains after a certain period of time under compression. The temperature and absorbed <span class="hlt">radiation</span> dose can dramatically impact this property. In this study the only independent environmental variable studied is the effect of <span class="hlt">radiation</span> at ambient temperatures. Two levels of <span class="hlt">radiation</span> exposure were studied, 1 MRad, and 10 MRad. One of the independent test parameters is the compression deflection during storage and in this test the value used was 25%. The need for a compression retention mechanism ruled out <span class="hlt">radiation</span> exposure in the compressed direction since the high atomic number materials for that device would block the <span class="hlt">radiation</span>. Therefore, an annular ring was chosen for the specimen shape. The procedures are, as closely as possible, based on ASTM D 6147-97. Since the data is readily obtained at the end of the stress relaxation test, the samples were also evaluated for compression set. Compression set is the essentially permanent deformation incurred in a seal after the seal is compressed for some period of time and then unloaded. Though this is indicative of potential sealing reliability, it is not as direct an indicator of seal performance as is stress relaxation. Compression set does not yield any useable, quantified information but is an indicator of viscoelastic deformation with time. The needed thickness measurements were obtained both from the unloading curves and direct measurement in general accordance with ASTM D395-03. The <span class="hlt">radiation</span> source for this testing was the Co60 gamma source located at Lawrence Livermore National Laboratory (LLNL). This source has an exposure vessel approximately 29.2cm (11.5-inch) tall with an inside diameter of 7.44cm (2.93-inch). Because of the geometry limits, cylindrical symmetry and limited volume, a standard stress relaxation test such as ASTM D 6147-97 could not be utilized and a modified test was developed. An additional constraint imposed by the vertical asymmetry of the <span class="hlt">radiation</span> dose in the exposure chamber was a limited height with reasonably uniform <span class="hlt">radiation</span> exposure. The specific dimensions and <span class="hlt">radiation</span> characteristics of the test cell are in Appendix A.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PUBMED&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/24136023"><span id="translatedtitle"><span class="hlt">Radiation-induced</span> gliomas in 2 pediatric patients with neurofibromatosis type 1: case study and summary of the literature.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Madden, Jennifer R; Rush, Sarah Z; Stence, Nicholas; Foreman, Nicholas K; Liu, Arthur K</p> <p>2014-03-01</p> <p>Neurofibromatosis type 1 (NF1) is a genetic disorder that predisposes patients to the formation of sporadic tumors and also increases the risk of <span class="hlt">radiation-induced</span> malignancies. The most commonly described <span class="hlt">radiation-induced</span> tumor in NF1 patients is a malignant peripheral nerve sheath tumor. We present 2 children with NF1 who received <span class="hlt">radiation</span> therapy and subsequently developed high-grade gliomas. We then review the current literature on <span class="hlt">radiation-induced</span> tumors in NF1 patients. Although <span class="hlt">radiation</span> may be the most appropriate therapy in specific situations for children with NF1, the secondary tumor risk should be carefully considered. PMID:24136023</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASA-TRS&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19730024107&hterms=Solid-state+Physics&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3D%2522Solid-state%2BPhysics%2522"><span id="translatedtitle">Study of interaction among silicon, lithium, oxygen and <span class="hlt">radiation-induced</span> defects for <span class="hlt">radiation</span>-hardened solar cells</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Berman, P. A.</p> <p>1973-01-01</p> <p>In order to improve reliability and the useful lifetime of solar cell arrays for space use, a program was undertaken to develop <span class="hlt">radiation</span>-hardened lithium-doped silicon solar cells. These cells were shown to be significantly more resistant to degradation by ionized particles than the presently used n-p nonlithium-doped silicon solar cells. The results of various analyses performed to develop a more complete understanding of the physics of the interaction among lithium, silicon, oxygen, and <span class="hlt">radiation-induced</span> defects are presented. A discussion is given of those portions of the previous model of <span class="hlt">radiation</span> damage annealing which were found to be in error and those portions which were upheld by these extensive investigations.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/61141877"><span id="translatedtitle">ANNEALING OF <span class="hlt">RADIATION</span> <span class="hlt">INDUCED</span> DEFECTS IN FUSED SILICA</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Levy</p> <p>1963-01-01</p> <p>The effects of purely ionizing <span class="hlt">radiation</span> on glasses and crystals lie in ; the redistribution of electrons and holes and the formation of color centers in ; impurities or defects. On the other hand, energetic particles such as fast ; neutrons form atom recoils and thus produce defects. The coloring of defects by, ; say, gamma rays could be used</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/33059190"><span id="translatedtitle">A stochastic model of <span class="hlt">radiation-induced</span> bone marrow damage</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>G. Cotlet; T. E. Blue</p> <p>2000-01-01</p> <p>A stochastic model, based on consensus principles from <span class="hlt">radiation</span> biology, is used to estimate bone-marrow stem cell pool survival (CFU-S and stroma cells) after irradiation. The dose response model consists of three coupled first order linear differential equations which quantitatively describe time dependent cellular damage, repair, and killing of red bone marrow cells. This system of differential equations is solved</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/29095701"><span id="translatedtitle">Ultraviolet <span class="hlt">Radiation</span> <span class="hlt">Induced</span> Suppression of Mantoux Reactions in Humans</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Diona L. Damian; Gary M. Halliday; Carol A. Taylor; Ross St C. Barnetson</p> <p>1998-01-01</p> <p>The effects of low dose ultraviolet (UV) <span class="hlt">radiation</span> on delayed type hypersensitivity responses to tuberculin purified protein derivative were investigated in 17 healthy, Mantoux-positive volunteers. Suberythemal and erythemal doses of solar simulated UV from a fluorescent lamp source were delivered to the subjects’ lower backs daily for five consecutive days. Mantoux testing with intradermally injected purified protein derivative was then</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/34044050"><span id="translatedtitle">Ultraviolet <span class="hlt">radiation</span> directly <span class="hlt">induces</span> pigment production by cultured human melanocytes</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Peter S. Friedmann; Barbara A. Gilchrest</p> <p>1987-01-01</p> <p>In humans the major stimulus for cutaneous pigmentation is ultraviolet <span class="hlt">radiation</span> (UVR). Little is known about the mechanism underlying this response, in part because of the complexity of interactions in whole epidermis. Using a recently developed culture system, human melanocytes were exposed daily to a physiologic range of UVR doses from a solar simulator. Responses were determined 24 hours after</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://www.stanford.edu/group/sherlocklab/pdfs/HELLAND_RADIOTH_ONC_2006.pdf"><span id="translatedtitle">Molecular radiobiology <span class="hlt">Radiation-induced</span> effects on gene expression</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Ford, James</p> <p></p> <p>the molecular basis underlying response to radiotherapy in breast cancer tissue. Material and Methods: Tumour Background and Purpose: Breast cancer is diagnosed worldwide in approximately one million women annually with breast cancer receiving <span class="hlt">radiation</span> therapy. Gene expression microarray analyses were performed to identify</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://www.hi.helsinki.fi/cgtg/downloads/Nokisalmi_Radiation-induced_upregulation_of_gene_expression_from_adenoviral_vectors_Int_J_Radiat_Oncol_Biol_Phys_2012.pdf"><span id="translatedtitle">Biology Contribution <span class="hlt">Radiation-Induced</span> Upregulation of Gene Expression From</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Hemminki, Akseli</p> <p></p> <p>) was studied with and without <span class="hlt">radiation</span> in three cell lines: breast cancer M4A4- LM3, prostate cancer PC-3MM2, Ph.D.,x Laura Ahtiainen, Ph.D.,*,y and Akseli Hemminki, M.D., Ph.D.*,y *Cancer Gene Therapy Group, Molecular Cancer Biology Program, Transplantation Laboratory, Haartman Institute, and Finnish Institute</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/servlets/purl/974877"><span id="translatedtitle">Simulation of ion beam <span class="hlt">induced</span> current in <span class="hlt">radiation</span> detectors and microelectronic devices.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Vizkelethy, Gyorgy</p> <p>2009-10-01</p> <p>Ionizing <span class="hlt">radiation</span> is known to cause Single Event Effects (SEE) in a variety of electronic devices. The mechanism that leads to these SEEs is current <span class="hlt">induced</span> by the <span class="hlt">radiation</span> in these devices. While this phenomenon is detrimental in ICs, this is the basic mechanism behind the operation of semiconductor <span class="hlt">radiation</span> detectors. To be able to predict SEEs in ICs and detector responses we need to be able to simulate the <span class="hlt">radiation</span> <span class="hlt">induced</span> current as the function of time. There are analytical models, which work for very simple detector configurations, but fail for anything more complex. On the other end, TCAD programs can simulate this process in microelectronic devices, but these TCAD codes costs hundreds of thousands of dollars and they require huge computing resources. In addition, in certain cases they fail to predict the correct behavior. A simulation model based on the Gunn theorem was developed and used with the COMSOL Multiphysics framework.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PUBMED&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/1940432"><span id="translatedtitle">Differential protection by two sunscreens from UV <span class="hlt">radiation-induced</span> immunosuppression.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Reeve, V E; Bosnic, M; Boehm-Wilcox, C; Ley, R D</p> <p>1991-10-01</p> <p>A controversy has arisen concerning the ability of sunscreens to protect mice from the immunosuppressive effects of UV <span class="hlt">radiation</span>. We have assessed the photoprotection in hairless mice of two sun protection factor (SPF)15 sunscreens containing different UVB (280-320-nm) absorbers, namely, octyl-N-dimethyl-p-aminobenzoate (o-PABA) or 2-ethylhexyl-p-methoxycinnamate (2-EHMC). Following three minimum erythemal exposures to UV <span class="hlt">radiation</span>, both systemic suppression of contact hypersensitivity to 2,4-dinitrofluorobenzene and induction of susceptibility to transplanted UV <span class="hlt">radiation-induced</span> tumor cells was established. Topically applied 2-EHMC sunscreen protected totally from both forms of immunosuppression, but the o-PABA sunscreen failed to protect, although both sunscreens were equally effective in protection from UV <span class="hlt">radiation-induced</span> erythema and edema. PMID:1940432</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/servlets/purl/10177329"><span id="translatedtitle"><span class="hlt">Radiation</span> <span class="hlt">induced</span> darkening of the optical elements in the Startracker camera</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>White, R.H.; Wirtenson, G.R.</p> <p>1993-03-01</p> <p>Optical glass flats that closely simulate the elements used in the Startracker lens designs were exposed to doses of ionizing <span class="hlt">radiation</span> ranging from 0.44 to 1300 krad. Photometer traces determined the transmittance of the samples as a function of both wavelength and dose for wavelengths in the range 300 to 1200 nm. Cerium stabilized glasses used in the <span class="hlt">radiation</span> stabilized Startracker system showed only a small amount of darkening for doses up to and exceeding 1 Mrad. Glasses used in the unstabilized Startracker design showed significant darkening to visible and ultra-violet spectra for doses as low as 5 krad. Plots of transmittance versus wavelength for various doses are given for each of the Startracker optical elements. <span class="hlt">Radiation</span> <span class="hlt">induced</span> absorption parameters that determine the <span class="hlt">radiation</span> <span class="hlt">induced</span> absorption coefficient are tabulated and plotted versus wavelength.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASA-TRS&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19730011000&hterms=helium+leaking&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dhelium%2Bleaking"><span id="translatedtitle">Energy Distribution of Electrons in <span class="hlt">Radiation</span> <span class="hlt">Induced</span>-Helium Plasmas. Ph.D. Thesis</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lo, R. H.</p> <p>1972-01-01</p> <p>Energy distribution of high energy electrons as they slow down and thermalize in a gaseous medium is studied. The energy distribution in the entire energy range from source energies down is studied analytically. A helium medium in which primary electrons are created by the passage of heavy-charged particles from nuclear reactions is emphasized. A <span class="hlt">radiation-induced</span> plasma is of interest in a variety of applications, such as <span class="hlt">radiation</span> pumped lasers and gaseous core nuclear reactors.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://www.springerlink.com/index/m2g155pj43q14303.pdf"><span id="translatedtitle"><span class="hlt">Radiation</span> Retinopathy Caused by Low Dose Irradiation and Antithyroid Drug-<span class="hlt">Induced</span> Systemic Vasculitis</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Koh-Hei Sonoda; Masahiro Yamamoto; Tatsuro Ishibashi</p> <p>2005-01-01</p> <p>Background: We report on a patient with Graves’ disease with <span class="hlt">radiation</span> retinopathy caused by lowdose irradiation and antithyroid drug-<span class="hlt">induced</span> antineutrophil cytoplasmic antibody (ANCA)-positive vasculitis. Case: A 38-year-old woman with Graves’ disease presented with bilateral blurred vision, microaneurysms, telangiectasia, and macular edema. The patient was examined by ophthalmoscopy and fluorescein angiography, and <span class="hlt">radiation</span> retinopathy was diagnosed. Observations: The patient had been</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://www.springerlink.com/index/r21k0r4634v41043.pdf"><span id="translatedtitle">Effect of Temperature on the Relaxation of <span class="hlt">Radiation-Induced</span> Coloration in Optical Glasses</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>V. I. Arbuzov; M. G. Kurochkina</p> <p>2003-01-01</p> <p>Optical and <span class="hlt">radiation</span>-resistant crown and flint glasses exposed to gamma irradiation at room temperature are investigated. The relaxation of <span class="hlt">radiation-induced</span> absorption in irradiated glasses is examined prior to and after short-term or long-term heat treatment at different temperatures in the range 20–150°C. It is established that an increase in the heat treatment temperature by even several tens of degrees leads</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/19274217"><span id="translatedtitle">Effects of Moisture on <span class="hlt">Radiation-Induced</span> Degradation in CMOS SOI Transistors</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Marty R. Shaneyfelt; James R. Schwank; Paul E. Dodd; Tom A. Hill; Scott M. Dalton; Scot E. Swanson</p> <p>2010-01-01</p> <p>The effects of moisture on <span class="hlt">radiation-induced</span> charge buildup in the oxides of a 0.35 ?m SOI technology are explored. Data show no observable effects of moisture-related aging on <span class="hlt">radiation</span> hardness. These results are in contrast to those of previous work performed on bulk MOS technologies fabricated in the 1980s. The cause of these differences do not appear to be due</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/16533193"><span id="translatedtitle">Melatonin protects human blood lymphocytes from <span class="hlt">radiation-induced</span> chromosome damage</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Vijayalaxmi; Russel J. Reiter; Martin L. Meltz</p> <p>1995-01-01</p> <p>Cells in human peripheral blood were treated in vitro with increasing concentrations of melatonin (0.5 or 1.0 or 2.0 mM) for 20 min at 37 ± 1°C and then exposed to 150 cGy ?-<span class="hlt">radiation</span> from a 137Cs source. The lymphocytes which were pre-treated with melatonin exhibited a significant and concentration-dependent decrease in the frequency of <span class="hlt">radiation-induced</span> chromosome damage as compared</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PMC&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1013116"><span id="translatedtitle">The significance of <span class="hlt">radiation-induced</span> chromosome abnormalities in radiological protection</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Dolphin, G. W.; Lloyd, D. C.</p> <p>1974-01-01</p> <p>A brief review is given of the production and analysis of chromosome aberrations <span class="hlt">induced</span> by ionizing <span class="hlt">radiation</span>. The various tissues in which it is possible to demonstrate aberrations are noted and particular emphasis is laid on the culture of peripheral blood lymphocytes. Some examples of recent applications of the technique are described. These are in the determination of suspected overdoses to <span class="hlt">radiation</span> workers, in estimating doses to radiotherapy patients, and investigating the depth/biological profile for a negative ? meson beam. PMID:4841086</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PUBMED&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/25708302"><span id="translatedtitle"><span class="hlt">Radiation</span> <span class="hlt">induced</span> depigmentation disorder in two patients with breast cancer: Exploring a rare accompaniment.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Biswas, Ahitagni; Chaudhari, Pritee B; Julka, Pramod Kumar; Rath, Goura Kishor</p> <p>2015-06-01</p> <p><span class="hlt">Radiation</span> <span class="hlt">induced</span> depigmentation disorder is a rare accompaniment. We herein report two patients of bilateral breast cancer developing depigmentation disorder, initially confined to the <span class="hlt">radiation</span> portal with subsequent generalization within few months of completion of whole breast radiotherapy. Both these patients had no prior history of vitiligo or other autoimmune disorder. This brief report highlights the importance of awareness of this association in appropriate decision making in susceptible patients thereby preventing this morbidity and its psychological ramifications. PMID:25708302</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/31666736"><span id="translatedtitle"><span class="hlt">Radiation-induced</span> liver disease after radiotherapy for hepatocellular carcinoma: clinical manifestation and dosimetric description</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Jason Chia-Hsien Cheng; Jian-Kuen Wu; Chao-Ming Huang; David Y. Huang; Skye H. Cheng; Yu-Mong Lin; James J. Jian; Po-Sheng Yang; Vincent P. Chuang; Andrew T. Huang</p> <p>2002-01-01</p> <p>Twelve patients with hepatocellular carcinoma and chronic hepatitis developed <span class="hlt">radiation-induced</span> liver disease (RILD) after three-dimensional conformal radiotherapy. Six patients died of RILD and six recovered. Mean prescribed dose was 50.6±4.3Gy, in a daily fraction of 1.8–2.0Gy. Commonly used dosimetric parameters, such as fraction volume of normal liver with <span class="hlt">radiation</span> dose >30Gy, prediction score, and normal tissue complication probability, failed to</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/30445818"><span id="translatedtitle"><span class="hlt">Radiation-induced</span> second cancers: the impact of 3D-CRT and IMRT</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Eric J Hall; Cheng-Shie Wuu</p> <p>2003-01-01</p> <p>Information concerning <span class="hlt">radiation-induced</span> malignancies comes from the A-bomb survivors and from medically exposed individuals, including second cancers in <span class="hlt">radiation</span> therapy patients. The A-bomb survivors show an excess incidence of carcinomas in tissues such as the gastrointestinal tract, breast, thyroid, and bladder, which is linear with dose up to about 2.5 Sv. There is great uncertainty concerning the dose–response relationship for</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/37061609"><span id="translatedtitle">p53Independent ceramide formation in human glioma cells during ?-<span class="hlt">radiation-induced</span> apoptosis</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>S Hara; S Nakashima; T Kiyono; M Sawada; S Yoshimura; T Iwama; Y Banno; J Shinoda; N Sakai</p> <p>2004-01-01</p> <p>Although the p53 tumor-suppressor gene product plays a critical role in apoptotic cell death <span class="hlt">induced</span> by DNA-damaging chemotherapeutic agents, human glioma cells with functional p53 were more resistant to ?-<span class="hlt">radiation</span> than those with mutant p53. U-87 MG cells with wild-type p53 were resistant to ?-<span class="hlt">radiation</span>. U87-W E6 cells that lost functional p53, by the expression of type 16 human papillomavirus</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PUBMED&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/24041870"><span id="translatedtitle">Non-targeted effects <span class="hlt">induced</span> by ionizing <span class="hlt">radiation</span>: mechanisms and potential impact on <span class="hlt">radiation</span> <span class="hlt">induced</span> health effects.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Morgan, William F; Sowa, Marianne B</p> <p>2015-01-01</p> <p>Not-targeted effects represent a paradigm shift from the "DNA centric" view that ionizing <span class="hlt">radiation</span> only elicits biological effects and subsequent health consequences as a result of an energy deposition event in the cell nucleus. While this is likely true at higher <span class="hlt">radiation</span> doses (>1 Gy), at low doses (<100 mGy) non-targeted effects associated with <span class="hlt">radiation</span> exposure might play a significant role. Here definitions of non-targeted effects are presented, the potential mechanisms for the communication of signals and signaling networks from irradiated cells/tissues are proposed, and the various effects of this intra- and intercellular signaling are described. We conclude with speculation on how these observations might lead to and impact long-term human health outcomes. PMID:24041870</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/277721"><span id="translatedtitle"><span class="hlt">Radiation</span> <span class="hlt">induced</span> thermally stimulated luminescence and conductivity in SIMOX oxides</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Martini, M.; Meinardi, F.; Rosetta, E.; Spinolo, G.; Vedda, A. [Univ. di Milano (Italy). Dipt. di Fisica] [Univ. di Milano (Italy). Dipt. di Fisica; Leray, J.L.; Paillet, P.; Autran, J.L. [CEA Centre d`Etudes de Bruyeres, Bruyeres-le-Chatel (France)] [CEA Centre d`Etudes de Bruyeres, Bruyeres-le-Chatel (France); Devine, R.A.B. [CNET-France Telecom, Meylan (France)] [CNET-France Telecom, Meylan (France)</p> <p>1996-06-01</p> <p>Thermally Stimulated Luminescence (TSL) and Conductivity (TSC) <span class="hlt">induced</span> by X-ray irradiation in SIMOX buried oxides have been studied from room temperature up to 400 C. The characteristics of an X-ray <span class="hlt">induced</span> TSL glow peak detected around 62 C are presented: specifically, results on the emission wavelength and trap depth are shown. The X-ray <span class="hlt">induced</span> TSC, observed at approximately 70 C, is due to the same trapped species responsible of the TSL emission. The stability after irradiation and dose dependence of both TSL and TSC signals have also been investigated. The results have been compared with similar studies on high temperature annealed thermal SiO{sub 2} films and bulk materials.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PUBMED&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/24137434"><span id="translatedtitle">Protective effect of tanshinone IIA against <span class="hlt">radiation-induced</span> ototoxicity in HEI-OC1 cells.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>DU, Shasha; Yao, Qiwei; Tan, Peixin; Xie, Guozhu; Ren, Chen; Sun, Quanquan; Zhang, Xiao; Zheng, Rong; Yang, Kaijun; Yuan, Yawei; Yuan, Quan</p> <p>2013-10-01</p> <p>Radiotherapy is a highly efficient treatment method for nasopharyngeal carcinoma that is often accompanied by significant ototoxic side-effects. The inner ear hair cells are particularly prone to serious injury following radiotherapy. Tanshinone IIA is a transcription factor inhibitor that is extracted from the traditional herbal medicine, Salvia miltiorrhiza Bunge. The present study investigated the effects of tanshinone IIA treatment on <span class="hlt">radiation-induced</span> toxicity in the HEI-OC1 hair cell line. Using an MTT assay and flow cytometry, the <span class="hlt">radiation-induced</span> weakening of the cells was observed to be alleviated when the cells were pre-treated with tanshinone IIA. <span class="hlt">Radiation</span> exposure promoted p65/nuclear factor (NF)-?B nuclear translocation and activated the p53/p21 pathway, two processes which play a significant role in <span class="hlt">radiation-induced</span> cell apoptosis. However, pre-treatment of the cells with tanshinone IIA inhibited p65/NF-?B nuclear translocation and p53/p21 pathway activation. These results demonstrate that tanshinone IIA is capable of protecting cochlear cells from <span class="hlt">radiation-induced</span> injury through the suppression of p65/NF-?B nuclear translocation and the p53/p21 signaling pathway. PMID:24137434</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASA-TRS&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20040112350&hterms=Oncogene&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D50%26Ntt%3DOncogene"><span id="translatedtitle"><span class="hlt">Radiation</span> <span class="hlt">induces</span> genomic instability and mammary ductal dysplasia in Atm heterozygous mice</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Weil, M. M.; Kittrell, F. S.; Yu, Y.; McCarthy, M.; Zabriskie, R. C.; Ullrich, R. L.</p> <p>2001-01-01</p> <p>Ataxia-telangiectasia (AT) is a genetic syndrome resulting from the inheritance of two defective copies of the ATM gene that includes among its stigmata radiosensitivity and cancer susceptibility. Epidemiological studies have demonstrated that although women with a single defective copy of ATM (AT heterozygotes) appear clinically normal, they may never the less have an increased relative risk of developing breast cancer. Whether they are at increased risk for <span class="hlt">radiation-induced</span> breast cancer from medical exposures to ionizing <span class="hlt">radiation</span> is unknown. We have used a murine model of AT to investigate the effect of a single defective Atm allele, the murine homologue of ATM, on the susceptibility of mammary epithelial cells to <span class="hlt">radiation-induced</span> transformation. Here we report that mammary epithelial cells from irradiated mice with one copy of Atm truncated in the PI-3 kinase domain were susceptible to <span class="hlt">radiation-induced</span> genomic instability and generated a 10% incidence of dysplastic mammary ducts when transplanted into syngenic recipients, whereas cells from Atm(+/+) mice were stable and formed only normal ducts. Since <span class="hlt">radiation-induced</span> ductal dysplasia is a precursor to mammary cancer, the results indicate that AT heterozygosity increases susceptibility to radiogenic breast cancer in this murine model system.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2014SPIE.9040E..1BY"><span id="translatedtitle">3D ultrasound Nakagami imaging for <span class="hlt">radiation-induced</span> vaginal fibrosis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yang, Xiaofeng; Rossi, Peter; Shelton, Joseph; Bruner, Debrorah; Tridandapani, Srini; Liu, Tian</p> <p>2014-03-01</p> <p><span class="hlt">Radiation-induced</span> vaginal fibrosis is a debilitating side-effect affecting up to 80% of women receiving radiotherapy for their gynecological (GYN) malignancies. Despite the significant incidence and severity, little research has been conducted to identify the pathophysiologic changes of vaginal toxicity. In a previous study, we have demonstrated that ultrasound Nakagami shape and PDF parameters can be used to quantify <span class="hlt">radiation-induced</span> vaginal toxicity. These Nakagami parameters are derived from the statistics of ultrasound backscattered signals to capture the physical properties (e.g., arrangement and distribution) of the biological tissues. In this paper, we propose to expand this Nakagami imaging concept from 2D to 3D to fully characterize <span class="hlt">radiation-induced</span> changes to the vaginal wall within the <span class="hlt">radiation</span> treatment field. A pilot study with 5 post-radiotherapy GYN patients was conducted using a clinical ultrasound scanner (6 MHz) with a mechanical stepper. A serial of 2D ultrasound images, with radio-frequency (RF) signals, were acquired at 1 mm step size. The 2D Nakagami shape and PDF parameters were calculated from the RF signal envelope with a sliding window, and then 3D Nakagami parameter images were generated from the parallel 2D images. This imaging method may be useful as we try to monitor <span class="hlt">radiation-induced</span> vaginal injury, and address vaginal toxicities and sexual dysfunction in women after radiotherapy for GYN malignancies.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PUBMED&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/24880906"><span id="translatedtitle">Imaging of nuclear factor ?B activation <span class="hlt">induced</span> by ionizing <span class="hlt">radiation</span> in human embryonic kidney (HEK) cells.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chishti, Arif Ali; Baumstark-Khan, Christa; Hellweg, Christine E; Reitz, Günther</p> <p>2014-08-01</p> <p>Ionizing <span class="hlt">radiation</span> modulates several signaling pathways resulting in transcription factor activation. Nuclear factor kappa B (NF-?B) is one of the most important transcription factors that respond to changes in the environment of a mammalian cell. NF-?B plays a key role not only in inflammation and immune regulation but also in cellular <span class="hlt">radiation</span> response. In response to DNA damage, NF-?B might inhibit apoptosis and promote carcinogenesis. Our previous studies showed that ionizing <span class="hlt">radiation</span> is very effective in <span class="hlt">inducing</span> biological damages. Therefore, it is important to understand the <span class="hlt">radiation-induced</span> NF-?B signaling cascade. The current study aims to improve existing mammalian cell-based reporter assays for NF-?B activation by the use of DD-tdTomato which is a destabilized variant of red fluorescent protein tdTomato. It is demonstrated that exposure of recombinant human embryonic kidney cells (HEK/293 transfected with a reporter constructs containing NF-?B binding sites in its promoter) to ionizing <span class="hlt">radiation</span> <span class="hlt">induces</span> NF-?B-dependent DD-tdTomato expression. Using this reporter assays, NF-?B signaling in mammalian cells was monitored by flow cytometry and fluorescence microscopy. Activation of NF-?B by the canonical pathway was found to be quicker than by the genotoxin- and stress-<span class="hlt">induced</span> pathway. X-rays activate NF-?B in HEK cells in a dose-dependent manner, and the extent of NF-?B activation is higher as compared to camptothecin. PMID:24880906</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/servlets/purl/10107117"><span id="translatedtitle">Transient <span class="hlt">radiation-induced</span> absorption in materials for the DOI laser</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Brannon, P.J.</p> <p>1995-01-01</p> <p>This is the final report on a series of experiments concerned with transient <span class="hlt">radiation-induced</span> absorption in materials for a Cr,Nd:GSGG laser. Both the Sandia National Laboratories SPR III pulsed reactor and the Hermes III pulsed X-ray machine are used as <span class="hlt">radiation</span> sources. The time dependence and the magnitude of the <span class="hlt">induced</span> absorption in filter glasses and in doped and undoped LiNbO{sub 3} Q-switch materials have been measured. Gain has been observed in Cr,Nd:GSGG, the laser medium, when it is irradiated by X-rays.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PMC&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2477724"><span id="translatedtitle">Non-Problematic Risks from Low-Dose <span class="hlt">Radiation-Induced</span> DNA Damage Clusters</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Hayes, Daniel P.</p> <p>2008-01-01</p> <p><span class="hlt">Radiation-induced</span> DNA damage clusters have been proposed and are usually considered to pose the threat of serious biological damage. This has been attributed to DNA repair debilitation or cessation arising from the complexity of cluster damage. It will be shown here, contrary to both previous suggestions and perceived wisdom, that <span class="hlt">radiation</span> <span class="hlt">induced</span> damage clusters contribute to non-problematic risks in the low-dose, low-LET regime. The very complexity of cluster damage which inhibits and/or compromises DNA repair will ultimately be responsible for the elimination and/or diminution of precancer-ous and cancerous cells. PMID:18648573</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/5986780"><span id="translatedtitle">Distinction between neoplastic and <span class="hlt">radiation-induced</span> brachial plexopathy, with emphasis on the role of EMG</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Harper, C.M. Jr.; Thomas, J.E.; Cascino, T.L.; Litchy, W.J.</p> <p>1989-04-01</p> <p>The results of clinical, radiologic, and electrophysiologic studies are retrospectively reviewed for 55 patients with neoplastic and 35 patients with <span class="hlt">radiation-induced</span> brachial plexopathy. The presence or absence of pain as the presenting symptom, temporal profile of the illness, presence of a discrete mass on CT of the plexus, and presence of myokymic discharges on EMG contributed significantly to the prediction of the underlying cause of the brachial plexopathy. The distribution of weakness and the results of nerve conduction studies were of no help in distinguishing neoplastic from <span class="hlt">radiation-induced</span> brachial plexopathy.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PMC&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4136475"><span id="translatedtitle">PHD Inhibition Mitigates and Protects Against <span class="hlt">Radiation-Induced</span> Gastrointestinal Toxicity via HIF2</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Taniguchi, Cullen M.; Miao, Yu Rebecca; Diep, Anh N.; Wu, Colleen; Rankin, Erinn B.; Atwood, Todd F.; Xing, Lei; Giaccia, Amato J.</p> <p>2014-01-01</p> <p><span class="hlt">Radiation-induced</span> gastrointestinal (GI) toxicity can be a major source of morbidity and mortality after <span class="hlt">radiation</span> exposure. There is an unmet need for effective preventative or mitigative treatments against the potentially fatal diarrhea and water loss <span class="hlt">induced</span> by <span class="hlt">radiation</span> damage to the GI tract. We report that prolyl hydroxylase inhibition by genetic knockout or pharmacologic inhibition of all PHD isoforms by the small molecule dimethyloxyallylglycine (DMOG) increases HIF expression, improves epithelial integrity, reduces apoptosis, and increases intestinal angiogenesis, all of which are essential for radioprotection. HIF2, but not HIF1, is both necessary and sufficient to prevent <span class="hlt">radiation-induced</span> GI toxicity and death. Increased VEGF expression contributes to the protective effects of HIF2, since inhibition of VEGF function reversed the radioprotection and radiomitigation afforded by DMOG. Additionally, mortality is reduced from abdominal or total body irradiation even when DMOG is given 24 hours after exposure. Thus, prolyl hydroxylase inhibition represents a new treatment strategy to protect against and mitigate GI toxicity from both therapeutic <span class="hlt">radiation</span> and potentially lethal <span class="hlt">radiation</span> exposures. PMID:24828078</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/20951192"><span id="translatedtitle">Pressure-<span class="hlt">Induced</span> Structural Transformation in <span class="hlt">Radiation</span>-Amorphized Zircon</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Trachenko, Kostya; Dove, Martin T.; Salje, E. K. H. [Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EQ (United Kingdom); Brazhkin, V. V.; Tsiok, O. B. [Institute for High Pressure Physics, Troitsk 142190 (Russian Federation)</p> <p>2007-03-30</p> <p>We study the response of a <span class="hlt">radiation</span>-amorphized material to high pressure. We have used zircon ZrSiO{sub 4} amorphized by natural <span class="hlt">radiation</span> over geologic times, and have measured its volume under high pressure, using the precise strain-gauge technique. On pressure increase, we observe apparent softening of the material, starting from 4 GPa. Using molecular dynamics simulation, we associate this softening with the amorphous-amorphous transformation accompanied by the increase of local coordination numbers. We observe permanent densification of the quenched sample and a nontrivial 'pressure window' at high temperature. These features point to a new class of amorphous materials that show a response to pressure which is distinctly different from that of crystals.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PMC&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3873222"><span id="translatedtitle">Cell Cycle Dependence of Ionizing <span class="hlt">Radiation-Induced</span> DNA Deletions and Antioxidant Radioprotection in Saccharomyces cerevisiae</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Hafer, Kurt; Rivina, Leena; Schiestl, Robert H.</p> <p>2013-01-01</p> <p>The yeast DEL assay is an effective method for measuring intrachromosomal recombination events resulting in DNA deletions that when occurring in mammalian cells are often associated with genomic instability and carcinogenesis. Here we used the DEL assay to measure ?-ray-<span class="hlt">induced</span> DNA deletions throughout different phases of yeast culture growth. Whereas yeast survival differed by only up to twofold throughout the yeast growth phase, proliferating cells in lag and early exponential growth phases were tenfold more sensitive to ionizing <span class="hlt">radiation-induced</span> DNA deletions than cells in stationary phase. <span class="hlt">Radiation-induced</span> DNA deletion potential was found to correlate directly with the fraction of cells in S/G2 phase. The ability of the antioxidants l-ascorbic acid and DMSO to protect against <span class="hlt">radiation-induced</span> DNA deletions was also measured within the different phases of yeast culture growth. Yeast cells in lag and early exponential growth phases were uniquely protected by antioxidant treatment, whereas nondividing cells in stationary phase could not be protected against the induction of DNA deletions. These results are compared with those from mammalian cell studies, and the implications for <span class="hlt">radiation-induced</span> carcinogenesis and radioprotection are discussed. PMID:20518659</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/27451986"><span id="translatedtitle"><span class="hlt">Radiation-Induced</span> Degradation Phenomena in Electrical Insulating Oils</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Sachio Yasufuku; Junichi Ise; Shigeo Kobayashi</p> <p>1978-01-01</p> <p>A mineral oil and a synthetic oil consisting of aromatic constituents were each irradiated by ¿rays at both room temper-ature ture and abo°t 70OC; the degree of the degradation was analyzed by means of gas chromatograms. The results showed that synthetic oil consisting of diarylalkane hydrocarbons has superior <span class="hlt">radiation</span>-resistant properties. In addition, when mineral oil containing sulfur compounds was irradiated</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/41763451"><span id="translatedtitle">Ionizing <span class="hlt">radiation</span> <span class="hlt">induced</span> degradation of tetrachlorobiphenyl in transformer oil</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Mahnaz Chaychian; Joseph Silverman; Mohamad Al-Sheikhly; Dianne L. Poster; Pedatsur Neta</p> <p>1999-01-01</p> <p>Complete degradation of 2,2[prime],6,6[prime]-tetrachlorobiphenyl (PCB-54) in transformer oil is achieved by ionizing <span class="hlt">radiation</span> without degradation of the oil. [gamma]-irradiation of transformer oil containing PCB-54 with a dose of 200 kGy results in complete destruction of the PCB. Analysis of samples irradiated with various doses demonstrated gradual degradation of PCB-54 and successive formation and degradation of trichloro-, dichloro-, and monochlorobiphenyl. The</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PMC&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=243757"><span id="translatedtitle">Solar <span class="hlt">radiation</span> <span class="hlt">induces</span> sublethal injury in Escherichia coli in seawater.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Kapuscinski, R B; Mitchell, R</p> <p>1981-01-01</p> <p>Sublethal injury was noted in Escherichia coli after cells were exposed to solar <span class="hlt">radiation</span>. Injury was detected by differential plate counts between complete and minimal media that were observed with sunlight-exposed cells but not with cells kept in the dark. Since addition of catalase or pyruvate to minimal medium overcame or repaired this injury, the catalase system appeared to be the site of injury. PMID:7013708</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASA-TRS&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19720039572&hterms=1073&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3D%2526%25231073"><span id="translatedtitle"><span class="hlt">Radiation-induced</span> extrinsic photoconductivity in Li-doped Si.</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Fenimore, E.; Mortka, T.; Corelli, J. C.</p> <p>1972-01-01</p> <p>Investigation of the effects of lithium on <span class="hlt">radiation</span>-produced complexes having long-time stability by examining the localized energy levels in the forbidden gap which give rise to extrinsic photoconductivity. The levels are found to disappear and in some cases shift with annealing in the 100-450 C temperature range. Due to the complexity of the system and the present lack of adequate theory, no complete analysis of the data obtained could be made.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2003AdSpR..31..119S"><span id="translatedtitle">Cognitive deficits <span class="hlt">induced</span> by 56Fe <span class="hlt">radiation</span> exposure</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shukitt-Hale, B.; Casadesus, G.; Cantuti-Castelvetri, I.; Rabin, B. M.; Joseph, J. A.</p> <p></p> <p>Exposing rats to particles of high energy and charge (e.g., 56Fe) disrupts neuronal systems and the behaviors mediated by them; these adverse behavioral and neuronal effects are similar to those seen in aged animals. Because cognition declines with age, and our previous study showed that <span class="hlt">radiation</span> disrupted Morris water maze spatial learning and memory performance, the present study used an 8-arm radial maze (RAM) to further test the cognitive behavioral consequences of <span class="hlt">radiation</span> exposure. Control rats or rats exposed to whole-body irradiation with 1.0 Gy of 1 GeV/n high-energy 56Fe particles (delivered at the alternating gradient synchrotron at Brookhaven National Laboratory) were tested nine months following exposure. <span class="hlt">Radiation</span> adversely affected RAM performance, and the changes seen parallel those of aging. Irradiated animals entered baited arms during the first 4 choices significantly less than did controls, produced their first error sooner, and also tended to make more errors as measured by re-entries into non-baited arms. These results show that irradiation with high-energy particles produces age-like decrements in cognitive behavior that may impair the ability of astronauts to perform critical tasks during long-term space travel beyond the magnetosphere.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PUBMED&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/22395787"><span id="translatedtitle">Cellular neoplastic transformation <span class="hlt">induced</span> by 916 MHz microwave <span class="hlt">radiation</span>.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yang, Lei; Hao, Dongmei; Wang, Minglian; Zeng, Yi; Wu, Shuicai; Zeng, Yanjun</p> <p>2012-08-01</p> <p>There has been growing concern about the possibility of adverse health effects resulting from exposure to microwave <span class="hlt">radiations</span>, such as those emitted by mobile phones. The purpose of this study was to investigate the cellular neoplastic transformation effects of electromagnetic fields. 916 MHz continuous microwave was employed in our study to simulate the electromagnetic <span class="hlt">radiation</span> of mobile phone. NIH/3T3 cells were adopted in our experiment due to their sensitivity to carcinogen or cancer promoter in environment. They were divided randomly into one control group and three microwave groups. The three microwave groups were exposed to 916 MHz EMF for 2 h per day with power density of 10, 50, and 90 w/m(2), respectively, in which 10 w/m(2) was close to intensity near the antenna of mobile phone. The morphology and proliferation of NIH/3T3 cells were examined and furthermore soft agar culture and animal carcinogenesis assay were carried out to determine the neoplastic promotion. Our experiments showed NIH/3T3 cells changed in morphology and proliferation after 5-8 weeks exposure and formed clone in soft agar culture after another 3-4 weeks depending on the exposure intensity. In the animal carcinogenesis study, lumps developed on the back of SCID mice after being inoculated into exposed NIH/3T3 cells for more than 4 weeks. The results indicate that microwave <span class="hlt">radiation</span> can promote neoplastic transformation of NIH/3T3cells. PMID:22395787</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/1037679"><span id="translatedtitle">Journal of Nuclear Materials - <span class="hlt">Radiation-induced</span> segregation and phase stability in ferritic-martensitic alloy T 91</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Jiao, Zhijie [ORNL; Busby, Jeremy T [ORNL; Was, Gary S [ORNL; Jiao, Zhijie [University of Michigan</p> <p>2010-01-01</p> <p><span class="hlt">Radiation-induced</span> segregation in ferritic martensitic alloy T 91 was studied to understand the behavior of solutes as a function of dose and temperature. Irradiations were conducted using 2 MeV protons to doses of 1, 3, 7 and 10 dpa at 400 C. <span class="hlt">Radiation-induced</span> segregation at prior austenite grain boundaries was measured, and various features of the irradiated microstructure were characterized, including grain boundary carbide coverage, the dislocation microstructure, <span class="hlt">radiation-induced</span> precipitation and irradiation hardening. Results showed that Cr, Ni and Si segregate to prior austenite grain boundaries at low dose, but segregation ceases and redistribution occurs above 3 dpa. Grain boundary carbide coverage mirrors <span class="hlt">radiation-induced</span> segregation. Irradiation <span class="hlt">induces</span> formation of Ni Si Mn and Cu-rich precipitates that account for the majority of irradiation hardening. <span class="hlt">Radiation-induced</span> segregation behavior is likely linked to the evolution of the precipitate and dislocation microstructures. 2010 Elsevier B.V. All rights reserved</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://www.its.caltech.edu/~vahalagr/APS2006Hossein-Zadeh.pdf"><span id="translatedtitle"><span class="hlt">Radiation-pressure-induced</span> regenerative mechanical oscillations in</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p></p> <p></p> <p>whispering-gallery mode system, " Physical Review letters, Volume 85, pp. 74-77, 2000 Pin ~1 mW, Q~108 Pcirc of an Optical Microcavity Phonon Mode" Physical Review Letters, Volume 94, 223902, June 2005 H. Rokhsari, T. J-Pressure <span class="hlt">Induced</span> Mechanical Oscillation of an optical Microcavity" Physical Review Letters, Volume 95, 033901, July</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://www.springerlink.com/index/u0327442x723l1u1.pdf"><span id="translatedtitle">Intensification of ultraviolet-<span class="hlt">induced</span> dermal damage by infrared <span class="hlt">radiation</span></span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Lorraine H. Kligman</p> <p>1982-01-01</p> <p>Abnormal dermal deposition of elastic fibers is the earliest and most striking effect of prolonged sun exposure (solar elastosis). The hyperplastic fibers are usually ascribed to ultraviolet (UV) rays. Nonetheless, other portions of the solar spectrum may play contributing roles. Heat, for example, enhances experimental UV tumorigenesis. Heat <span class="hlt">induces</span> erythema ab igne in which the structural alterations resemble those of</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2013JPhCS.426a2034L"><span id="translatedtitle">Proton <span class="hlt">induced</span> dielectron <span class="hlt">radiation</span> off Nb: Pt and Y distributions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lorenz, M.; Weber, M.; Agakishiev, G.; Behnke, C.; Belver, D.; Belyaev, A.; Berger-Chen, J. C.; Blanco, A.; Blume, C.; Böhmer, M.; Cabanelas, P.; Chernenko, S.; Dritsa, C.; Dybczak, A.; Epple, E.; Fabbietti, L.; Fateev, O.; Fonte, P.; Friese, J.; Fröhlich, I.; Galatyuk, T.; Garzón, J. A.; Gill, K.; Golubeva, M.; González-Díaz, D.; Guber, F.; Gumberidze, M.; Harabasz, S.; Hennino, T.; Holzmann, R.; Huck, P.; Hhne, C.; Ierusalimov, A.; Ivashkin, A.; Jurkovic, M.; Kämpfer, B.; Karavicheva, T.; Koenig, I.; Koenig, W.; Kolb, B. W.; Korcyl, G.; Kornakov, G.; Kotte, R.; Krása, A.; Krebs, E.; Krizek, F.; Kuc, H.; Kugler, A.; Kurepin, A.; Kurilkin, A.; Kurilkin, P.; Ladygin, V.; Lalik, R.; Lang, S.; Lapidus, K.; Lebedev, A.; Lopes, L.; Maier, L.; Mangiarotti, A.; Markert, J.; Metag, V.; Michel, J.; Müntz, C.; Münzer, R.; Naumann, L.; Palka, M.; Parpottas, Y.; Pechenov, V.; Pechenova, O.; Pietraszko, J.; Przygoda, W.; Ramstein, B.; Rehnisch, L.; Reshetin, A.; Rustamov, A.; Sadovsky, A.; Salabura, P.; Scheib, T.; Schuldes, H.; Siebenson, J.; Sobolev, Yu G.; Spataro, S.; Ströbele, H.; Stroth, J.; Strzempek, P.; Sturm, C.; Svoboda, O.; Tarantola, A.; Teilab, K.; Tlusty, P.; Traxler, M.; Tsertos, H.; Vasiliev, T.; Wagner, V.; Wendisch, C.; Wüstenfeld, J.; Yurevich, S.; Zanevsky, Y.; Hades Collaboration</p> <p>2013-03-01</p> <p>Following our recent letter [1] on inclusive e+e- pair production in proton <span class="hlt">induced</span> reactions at Ekin = 3.5 GeV on the nucleus Nb, we present here in addition the transverse and rapidity distributions for various e+e- invariant mass bins and compare them to reference data measured in p+p reactions.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/5019066"><span id="translatedtitle"><span class="hlt">Radiation-induced</span> chromosomal inversions in mice. Technical progress report</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Roderick, T.H.</p> <p>1986-01-01</p> <p>Chromosomal inversions are being produced for the purpose of establishing efficient systems for assessing <span class="hlt">induced</span> and spontaneous heritable mutations. The inversions and other chromosomal aberrations produced are used to ask basic questions about meiosis and reproductive performance. Chromosomal structure is being studied by identifying the cytological location of genes and break points related to the inversions. 2 tabs.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://www.springerlink.com/index/v7t3861581t80pw1.pdf"><span id="translatedtitle"><span class="hlt">Radiation-induced</span> hyperdiploidy in Hyoscyamus niger L</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>U. C. Lavania; R. K. Lal; J. R. Sharma</p> <p>1985-01-01</p> <p>Summary A hyperdiploid plant type, approaching the triploid chromosome number, and representing possibly a high level of tetrasomy, was recorded in the progeny of a gamma ray-<span class="hlt">induced</span> unbranched desynaptic mutant in the M4 generation. Its meiotic behavior and its possible importance for deriving diverse hyperdiploid lines from desynaptic mutants are outlined.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/323914"><span id="translatedtitle">Microscopic mechanisms of <span class="hlt">radiation-induced</span> proton density decay in SiO{sub 2} films</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Karna, S.P.; Pugh, R.D.; Chavez, J.R.; Shedd, W.; Brothers, C.P.; Singaraju, B.K. [Air Force Research Lab., Kirtland AFB, NM (United States)] [Air Force Research Lab., Kirtland AFB, NM (United States); Vitiello, M.; Pacchioni, G. [Univ. di Milano (Italy). Dipt. di Scienza dei Materiali] [Univ. di Milano (Italy). Dipt. di Scienza dei Materiali; Devine, R.A.B. [French Telecom-CNET, Meylan (France)] [French Telecom-CNET, Meylan (France)</p> <p>1998-12-01</p> <p>In order to understand the physics of <span class="hlt">radiation-induced</span> proton density decay in thin SiO{sub 2} films, the authors performed ab initio Hartree-Fock calculations of the potential energy curves for the interaction between model oxide clusters and H in two charge states. The calculated results led to two separate proposed mechanisms for proton density decay in thin SiO{sub 2} films: (1) electronic excitation involving hot phonon levels of the ground electronic state at low photon-energy <span class="hlt">radiation</span> and (2) electron capture by protons at high photon-energy <span class="hlt">radiation</span>. The proposed mechanisms qualitatively explain recent experimental observations.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2010JAP...107l3119Z"><span id="translatedtitle">Design of terahertz detector based on <span class="hlt">radiation-induced</span> magnetoresistance oscillations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhou, Q. S.; Cao, J. C.; Qi, M.</p> <p>2010-06-01</p> <p>We have investigated the longitudinal resistivity of two-dimensional (2D) electron gas driven by microwave and magnetic field by using the balance-equation theory. <span class="hlt">Radiation-induced</span> magnetoresistance oscillations have been reproduced. The period-in-the-inverse-magnetic-field is determined by <span class="hlt">radiation</span> frequency. This property can be used to design a terahertz detector. The detection is realized by applying a time-varying magnetic field on a 2D electron device and then measuring the difference of longitudinal resistivity with and without <span class="hlt">radiation</span>. This kind of detector has high sensitivity and high immunity.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/servlets/purl/5459042"><span id="translatedtitle"><span class="hlt">Radiation-induced</span> electrical breakdown of helium in fusion reactor superconducting magnet systems</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Perkins, L.J.</p> <p>1983-12-02</p> <p>A comprehensive theoretical study has been performed on the reduction of the electrical breakdown potential of liquid and gaseous helium under neutron and gamma <span class="hlt">radiation</span>. Extension of the conventional Townsend breakdown theory indicates that <span class="hlt">radiation</span> fields at the superconducting magnets of a typical fusion reactor are potentially capable of significantly reducing currently established (i.e., unirradiated) helium breakdown voltages. Emphasis is given to the implications of these results including future deployment choices of magnet cryogenic methods (e.g., pool-boiling versus forced-flow), the possible impact on magnet shielding requirements and the analogous situation for <span class="hlt">radiation-induced</span> electrical breakdown in fusion RF transmission systems.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PUBMED&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/25015672"><span id="translatedtitle">Late-onset <span class="hlt">radiation-induced</span> vasculopathy and stroke in a child with medulloblastoma.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bansal, Lalit R; Belair, Jeffrey; Cummings, Dana; Zuccoli, Giulio</p> <p>2015-05-01</p> <p>We report a case of a 15-year-old boy who presented to our institution with left-sided weakness and slurred speech. He had a history of medulloblastoma diagnosed at 3 years of age, status postsurgical resection and craniospinal <span class="hlt">radiation</span>. Magnetic resonance imaging (MRI) of brain revealed a right paramedian pontine infarction, suspected secondary to late-onset <span class="hlt">radiation-induced</span> vasculopathy of the vertebrobasilar system. <span class="hlt">Radiation</span> to the brain is associated with increased incidence of ischemic stroke. Clinicians should have a high index of suspicion for stroke when these patients present with new neurologic symptoms. PMID:25015672</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2013JChPh.139l1914M"><span id="translatedtitle">Electrostatic origin of in vitro aggregation of human ?-<span class="hlt">crystallin</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mohr, Benjamin G.; Dobson, Cassidy M.; Garman, Scott C.; Muthukumar, Murugappan</p> <p>2013-09-01</p> <p>The proteins ?-, ?-, and ?-<span class="hlt">crystallins</span> are the major components of the lens in the human eye. Using dynamic light scattering method, we have performed in vitro investigations of protein-protein interactions in dilute solutions of human ?-<span class="hlt">crystallin</span> and ?-<span class="hlt">crystallin</span>. We find that ?-<span class="hlt">crystallin</span> spontaneously aggregates into finite-sized clusters in phosphate buffer solutions. There are two distinct populations of unaggregated and aggregated ?-<span class="hlt">crystallins</span> in these solutions. On the other hand, ?-<span class="hlt">crystallin</span> molecules are not aggregated into large clusters in solutions of ?-<span class="hlt">crystallin</span> alone. When ?-<span class="hlt">crystallin</span> and ?-<span class="hlt">crystallin</span> are mixed in phosphate buffer solutions, we demonstrate that the clusters of ?-<span class="hlt">crystallin</span> are prevented. By further investigating the roles of temperature, protein concentration, pH, salt concentration, and a reducing agent, we show that the aggregation of ?-<span class="hlt">crystallin</span> under our in vitro conditions arises from non-covalent electrostatic interactions. In addition, we show that aggregation of ?-<span class="hlt">crystallin</span> occurs under the dilute in vitro conditions even in the absence of oxidizing agents that can <span class="hlt">induce</span> disulfide cross-links, long considered to be responsible for human cataracts. Aggregation of ?-<span class="hlt">crystallin</span> when maintained under reducing conditions suggests that oxidation does not contribute to the aggregation in dilute solutions.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/1600807"><span id="translatedtitle">Comparison of hot-carrier and <span class="hlt">radiation</span> <span class="hlt">induced</span> increases in base current in bipolar transistors</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>R. L. Pease; S. L. Kosier; R. D. Schrimpf; W. E. Combs; M. Davey; M. Delaus; D. M. Fleetwood</p> <p>1994-01-01</p> <p>A comparison was made between hot-carrier stress <span class="hlt">induced</span> and ionizing-<span class="hlt">radiation</span> <span class="hlt">induced</span> increases in the base current of bipolar linear microcircuit transistors from two process technologies. The comparison was made on the basis of a failure stress in seconds and a failure dose in rad(SiO2) for a failure criterion of ?I B=2 nA measured at an IC of 1 ?A and</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PUBMED&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/22119559"><span id="translatedtitle">Effects of exogenous carbon monoxide on <span class="hlt">radiation-induced</span> bystander effect in zebrafish embryos in vivo.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Choi, V W Y; Wong, M Y P; Cheng, S H; Yu, K N</p> <p>2012-07-01</p> <p>In the present work, the influence of a low concentration of exogenous carbon monoxide (CO) liberated from tricarbonylchloro(glycinato)ruthenium (II) (CORM-3) on the <span class="hlt">radiation</span> <span class="hlt">induced</span> bystander effect (RIBE) in vivo between embryos of the zebrafish was studied. RIBE was assessed through the number of apoptotic signals revealed on embryos at 25 h post fertilization (hpf). A significant attenuation of apoptosis on the bystander embryos <span class="hlt">induced</span> by RIBE in a CO concentration dependent manner was observed. PMID:22119559</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/23977943"><span id="translatedtitle">Effect of structure in charge on <span class="hlt">radiation-induced</span> reactions in micellar systems</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>J. Kerry Thomas</p> <p>1977-01-01</p> <p>A study of <span class="hlt">radiation-induced</span> reactions in micellar systems included the following topics: location of the probe molecule in the micelle, reaction of noncharged species in micelles, external quenching of pyrene fluorescence, reaction of e\\/sub aq\\/⁻, and photoionization. The effect of charge and structure on reactions <span class="hlt">induced</span> by low or high-energy photons or fast electrons was ascertained. A comparison of the</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PMC&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2949714"><span id="translatedtitle">Emerging role of <span class="hlt">radiation</span> <span class="hlt">induced</span> bystander effects: Cell communications and carcinogenesis</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2010-01-01</p> <p>Ionizing <span class="hlt">radiation</span> is an invaluable diagnostic and treatment tool used in various clinical applications. On the other hand, <span class="hlt">radiation</span> is a known cytotoxic with a potential DNA damaging and carcinogenic effects. However, the biological effects of low and high linear energy transfer (LET) <span class="hlt">radiations</span> are considerably more complex than previously thought. In the past decade, evidence has mounted for a novel biological phenomenon termed as "bystander effect" (BE), wherein directly irradiated cells transmit damaging signals to non-irradiated cells thereby <span class="hlt">inducing</span> a response similar to that of irradiated cells. BE can also be <span class="hlt">induced</span> in various cells irrespective of the type of <span class="hlt">radiation</span>, and the BE may be more damaging in the longer term than direct <span class="hlt">radiation</span> exposure. BE is mediated either through gap-junctions or via soluble factors released by irradiated cells. DNA damage response mechanisms represent a vital line of defense against exogenous and endogenous damage caused by <span class="hlt">radiation</span> and promote two distinct outcomes: survival and the maintenance of genomic stability. The latter is critical for cancer avoidance. Therefore, efforts to understand and modulate the bystander responses will provide new approaches to cancer therapy and prevention. This review overviews the emerging role of BE of low and high LET <span class="hlt">radiations</span> on the genomic instability of bystander cells and its possible implications for carcinogenesis. PMID:20831828</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PUBMED&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/20831828"><span id="translatedtitle">Emerging role of <span class="hlt">radiation</span> <span class="hlt">induced</span> bystander effects: Cell communications and carcinogenesis.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Baskar, Rajamanickam</p> <p>2010-01-01</p> <p>Ionizing <span class="hlt">radiation</span> is an invaluable diagnostic and treatment tool used in various clinical applications. On the other hand, <span class="hlt">radiation</span> is a known cytotoxic with a potential DNA damaging and carcinogenic effects. However, the biological effects of low and high linear energy transfer (LET) <span class="hlt">radiations</span> are considerably more complex than previously thought. In the past decade, evidence has mounted for a novel biological phenomenon termed as "bystander effect" (BE), wherein directly irradiated cells transmit damaging signals to non-irradiated cells thereby <span class="hlt">inducing</span> a response similar to that of irradiated cells. BE can also be <span class="hlt">induced</span> in various cells irrespective of the type of <span class="hlt">radiation</span>, and the BE may be more damaging in the longer term than direct <span class="hlt">radiation</span> exposure. BE is mediated either through gap-junctions or via soluble factors released by irradiated cells. DNA damage response mechanisms represent a vital line of defense against exogenous and endogenous damage caused by <span class="hlt">radiation</span> and promote two distinct outcomes: survival and the maintenance of genomic stability. The latter is critical for cancer avoidance. Therefore, efforts to understand and modulate the bystander responses will provide new approaches to cancer therapy and prevention. This review overviews the emerging role of BE of low and high LET <span class="hlt">radiations</span> on the genomic instability of bystander cells and its possible implications for carcinogenesis. PMID:20831828</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/968382"><span id="translatedtitle"><span class="hlt">Radiation-induced</span> optical response of single-crystal and polycrystalline YAG.</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Meister, Dorothy C.; Simmons-Potter, Kelly (University of Arizona, Tucson, AZ); Vaddigiri, Aruna (University of Arizona, Tucson, AZ); Thomes, William Joseph, Jr.</p> <p>2005-07-01</p> <p>Exposure of optical materials to transient-ionizing-<span class="hlt">radiation</span> fields can give rise to transient and/or permanent photodarkening effects. In laser materials, such as YAG, such <span class="hlt">induced</span> optical loss can result in significant degradation of the lasing characteristic of the material, making its selection for optical device applications in <span class="hlt">radiation</span> environments unfeasible. In the present study, the effects of ionizing <span class="hlt">radiation</span> on the optical response of undoped and 1.1% Nd-doped single-crystal and polycrystalline YAG have been investigated. In the undoped materials it is seen that both laser materials exhibit significant loss at the 1.06 ?m lasing wavelength following exposure to a 40 krad, 30 nsec pulse of gamma <span class="hlt">radiation</span>. In the undoped single-crystal samples, the transmission loss is initially large but exhibits a rapid recovery. By contrast, the undoped polycrystalline YAG experiences an initial 100% loss in transmission, becoming totally opaque at 1.06 ?m following the <span class="hlt">radiation</span> pulse. This loss is slow to recover and a large residual permanent photodarkening effect is observed. Nd-doping improves the optical response of the materials in that the <span class="hlt">radiation-induced</span> optical loss is substantially smaller in both the polycrystalline and single-crystal YAG samples. Preliminary results on the <span class="hlt">radiation</span> response of elevated-temperature samples will also be reported.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PMC&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4128341"><span id="translatedtitle">Unlocking the Combination: Potentiation of <span class="hlt">Radiation-Induced</span> Antitumor Responses with Immunotherapy</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Wattenberg, Max M.; Fahim, Ahmed; Ahmed, Mansoor M.; Hodge, James W.</p> <p>2014-01-01</p> <p>There is increasing evidence of the potential for <span class="hlt">radiation</span> therapy to generate antitumor immune responses. The mechanisms of this immune-activating potential include actions on tumor cells such as immunogenic cell death and phenotypic change. <span class="hlt">Radiation</span> modulates tumor cell surface expression of cell death receptors, tumor-associated antigens and adhesion molecules. This process of immunomodulation sensitizes tumor cells to immune-mediated killing. <span class="hlt">Radiation</span> also affects immune compartments, including antigen-presenting cells, cytotoxic T lymphocytes and humoral immunity, leading to specific antitumor immune responses. Recognizing the importance of immunity as a potentiator of response to <span class="hlt">radiation</span> leads to rational augmentation of antitumor immunity by combining <span class="hlt">radiation</span> and immunotherapy. Targeted immunotherapy manipulates the immune system in a way that best synergizes with <span class="hlt">radiation</span>. This article discusses the ability of <span class="hlt">radiation</span> monotherapy to <span class="hlt">induce</span> antitumor immunity, with a focus on the effect of <span class="hlt">radiation</span> on antigen-presenting cells and cytotoxic T lymphocytes. We define two important responses generated by tumor cells, immunogenic cell death and immunomodulation, both of which are <span class="hlt">radiation</span> dose-dependent. In conclusion, we describe the translation of several combination therapies from the preclinical to the clinical setting and identify opportunities for further exploration. PMID:24960415</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2014ApPhL.105c1907K"><span id="translatedtitle">Self-organization of a periodic structure between amorphous and <span class="hlt">crystalline</span> phases in a GeTe thin film <span class="hlt">induced</span> by femtosecond laser pulse amorphization</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Katsumata, Y.; Morita, T.; Morimoto, Y.; Shintani, T.; Saiki, T.</p> <p>2014-07-01</p> <p>A self-organized fringe pattern in a single amorphous mark of a GeTe thin film was formed by multiple femtosecond pulse amorphization. Micro Raman measurement indicates that the fringe is a periodic alternation between <span class="hlt">crystalline</span> and amorphous phases. The period of the fringe is smaller than the irradiation wavelength and the direction is parallel to the polarization direction. Snapshot observation revealed that the fringe pattern manifests itself via a complex but coherent process, which is attributed to crystallization properties unique to a nonthermally amorphized phase and the distinct optical contrast between <span class="hlt">crystalline</span> and amorphous phases.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PMC&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3762274"><span id="translatedtitle">Whole Brain <span class="hlt">Radiation-Induced</span> Cognitive Impairment: Pathophysiological Mechanisms and Therapeutic Targets</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Lee, Yong Woo; Cho, Hyung Joon; Lee, Won Hee; Sonntag, William E.</p> <p>2012-01-01</p> <p><span class="hlt">Radiation</span> therapy, the most commonly used for the treatment of brain tumors, has been shown to be of major significance in tu-mor control and survival rate of brain tumor patients. About 200,000 patients with brain tumor are treated with either partial large field or whole brain <span class="hlt">radiation</span> every year in the United States. The use of <span class="hlt">radiation</span> therapy for treatment of brain tumors, however, may lead to devastating functional deficits in brain several months to years after treatment. In particular, whole brain <span class="hlt">radiation</span> therapy results in a significant reduction in learning and memory in brain tumor patients as long-term consequences of treatment. Although a number of in vitro and in vivo studies have demonstrated the pathogenesis of <span class="hlt">radiation</span>-mediated brain injury, the cel-lular and molecular mechanisms by which <span class="hlt">radiation</span> <span class="hlt">induces</span> damage to normal tissue in brain remain largely unknown. Therefore, this review focuses on the pathophysiological mechanisms of whole brain <span class="hlt">radiation-induced</span> cognitive impairment and the iden-tification of novel therapeutic targets. Specifically, we review the current knowledge about the effects of whole brain <span class="hlt">radiation</span> on pro-oxidative and pro-inflammatory pathways, matrix metalloproteinases (MMPs)/tissue inhibitors of metalloproteinases (TIMPs) system and extracellular matrix (ECM), and physiological angiogenesis in brain. These studies may provide a foundation for defin-ing a new cellular and molecular basis related to the etiology of cognitive impairment that occurs among patients in response to whole brain <span class="hlt">radiation</span> therapy. It may also lead to new opportunities for therapeutic interventions for brain tumor patients who are undergoing whole brain <span class="hlt">radiation</span> therapy. PMID:24009822</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PMC&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4476126"><span id="translatedtitle">Detection of highly conductive surface electron states in topological <span class="hlt">crystalline</span> insulators Pb1?xSnxSe using laser terahertz <span class="hlt">radiation</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Egorova, S. G.; Chernichkin, V. I.; Ryabova, L. I.; Skipetrov, E. P.; Yashina, L. V.; Danilov, S. N.; Ganichev, S. D.; Khokhlov, D. R.</p> <p>2015-01-01</p> <p>We suggest a method for detection of highly conductive surface electron states including topological ones. The method is based on measurements of the photoelectromagnetic effect using terahertz laser pulses. In contrast to conventional transport measurements, the method is not sensitive to the bulk conductivity. The method is demonstrated on an example of topological <span class="hlt">crystalline</span> insulators Pb1?xSnxSe. It is shown that highly conductive surface electron states are present in Pb1?xSnxSe both in the inverse and direct electron energy spectrum. PMID:26096529</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASA-TRS&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20040087726&hterms=BYSTANDER&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DBYSTANDER"><span id="translatedtitle">Non-targeted and delayed effects of exposure to ionizing <span class="hlt">radiation</span>: II. <span class="hlt">Radiation-induced</span> genomic instability and bystander effects in vivo, clastogenic factors and transgenerational effects</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Morgan, William F.</p> <p>2003-01-01</p> <p>The goal of this review is to summarize the evidence for non-targeted and delayed effects of exposure to ionizing <span class="hlt">radiation</span> in vivo. Currently, human health risks associated with <span class="hlt">radiation</span> exposures are based primarily on the assumption that the detrimental effects of <span class="hlt">radiation</span> occur in irradiated cells. Over the years a number of non-targeted effects of <span class="hlt">radiation</span> exposure in vivo have been described that challenge this concept. These include <span class="hlt">radiation-induced</span> genomic instability, bystander effects, clastogenic factors produced in plasma from irradiated individuals that can cause chromosomal damage when cultured with nonirradiated cells, and transgenerational effects of parental irradiation that can manifest in the progeny. These effects pose new challenges to evaluating the risk(s) associated with <span class="hlt">radiation</span> exposure and understanding <span class="hlt">radiation-induced</span> carcinogenesis.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/48851826"><span id="translatedtitle"><span class="hlt">Radiation-Induced</span> Mutations for Date Palm Improvement</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>S. M. Jain</p> <p></p> <p>\\u000a Micropropagation technique is used for rapid shoot proliferation of date palm. Somatic embryogenesis is meant for clonal propagation\\u000a of date palm and genetic gains can be captured through it, which is rather difficult by zygotic embryo due to its heterozygous\\u000a nature. Genetic variability is highly desirable for the genetic improvement of crops, which can be either spontaneous or <span class="hlt">induced</span>\\u000a by</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://www.sbpt.org.br/downloads/arquivos/Com_DIP/Interstitial_Lung_Disease_Induced_Drugs_Radiation_Respiration_2004.pdf"><span id="translatedtitle">Interstitial Lung Disease <span class="hlt">Induced</span> by Drugs and <span class="hlt">Radiation</span></span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Philippe Camus; Annlyse Fanton; Philippe Bonniaud; Clio Camus; Pascal Foucher</p> <p>2004-01-01</p> <p>An ever-increasing number of drugs can reproduce variegated patterns of naturally occurring interstitial lung disease (ILD), including most forms of interstitial pneumonias, alveolar involvement and, rarely, vasculitis. Drugs in one therapeutic class may collectively produce the same pattern of involvement. A few drugs can produce more than one pattern of ILD. The diagnosis of drug-<span class="hlt">induced</span> ILD (DI-ILD) essentially rests on</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://oaktrust.library.tamu.edu//handle/1969.1/ETD-TAMU-1965-THESIS-M134"><span id="translatedtitle"><span class="hlt">Radiation-induced</span> chromosomal aberrations at different dose-rates </span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>McDaniel, Jackson Dean</p> <p>1965-01-01</p> <p>spermatogonia is presented in Table V(A). From the graphic presentatim of these data (Figure 5A) it is indicated, but not statistically significant, that high-dose-rate levels of <span class="hlt">radiation</span> are more effective in suppressing the mitotic index...) of these data suggests a progressive decrease in mitotic activity as the dose-rate is increased. Table V. Per cent of cells in metaphase, anaphase, and telophase per ane thousand spermatogania (A) and spermatocytes (B) eight hours following a total-body dose...</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PUBMED&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/22034846"><span id="translatedtitle">Genome-wide microarray analysis of human fibroblasts in response to ? <span class="hlt">radiation</span> and the <span class="hlt">radiation-induced</span> bystander effect.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kalanxhi, Erta; Dahle, Jostein</p> <p>2012-01-01</p> <p><span class="hlt">Radiation-induced</span> bystander effects have been studied extensively due to their potential implications for cancer therapy and <span class="hlt">radiation</span> protection; however, a complete understanding of the molecular mechanisms remains to be elucidated. In this study, we monitored transcriptional responses to ? <span class="hlt">radiation</span> in irradiated and bystander fibroblasts simultaneously employing a genome-wide microarray approach to determine factors that may be modulated in the generation or propagation of the bystander effect. For the microarray data we employed analysis at both the single-gene and gene-set level to place the findings in a biological context. Unirradiated bystander fibroblasts that were recipients of growth medium harvested from irradiated cultures 2 h after exposure to 2 Gy displayed transient enrichment in gene sets belonging to ribosome, oxidative phosphorylation and neurodegenerative disease pathways associated with mitochondrial dysfunctions. The response to direct irradiation was characterized by induction of signaling and apoptosis genes and the gradual formation of a cellular immune response. A set of 14 genes, many of which were regulated by p53, were found to be <span class="hlt">induced</span> early after irradiation (prior to medium transfer) and may be important in the generation or propagation of the bystander effect. PMID:22034846</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/81190"><span id="translatedtitle">Modulation of <span class="hlt">radiation-induced</span> apoptosis and G{sub 2}/M block in murine T-lymphoma cells</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Palayoor, S.T.; Macklis, R.M.; Bump, E.A.; Coleman, C.N. [Harvard Medical School, Boston, MA (United States)</p> <p>1995-03-01</p> <p><span class="hlt">Radiation-induced</span> apoptosis in lymphocyte-derived cell lines is characterized by endonucleolytic cleavage of cellular DNA within hours after <span class="hlt">radiation</span> exposure. We have studied this phenomenon qualitatively (DNA gel electrophoresis) and quantitatively (diphenylamine reagent assay) in murine EL4 T-lymphoma cells exposed to {sup 137}Cs {gamma} irradiation. Fragmentation was discernible within 18-24 h after exposure. It increased with time and dose and reached a plateau after 8 Gy of {gamma} <span class="hlt">radiation</span>. We studied the effect of several pharmacological agents on the <span class="hlt">radiation-induced</span> G{sub 2}/M block and DNA fragmentation. The agents which reduced the <span class="hlt">radiation-induced</span> G{sub 2}/M-phase arrest (caffeine, theobromine, theophylline and 2-aminopurine) enhanced the degree of DNA fragmentation at 24 h. In contrast, the agents which sustained the <span class="hlt">radiation-induced</span> G{sub 2}/M-phase arrest (TPA, DBcAMP, IBMX and 3-aminobenzamide) inhibited the DNA fragmentation at 24 h. These studies on EL4 lymphoma cells are consistent with the hypothesis that cells with <span class="hlt">radiation-induced</span> genetic damage are eliminated by apoptosis subsequent to a G{sub 2}/M block. Furthermore, it may be possible to modulate the process of <span class="hlt">radiation-induced</span> apoptosis in lymphoma cells with pharmacological agents that modify the <span class="hlt">radiation-induced</span> G{sub 2}/M block, and to use this effect in the treatment of patients with malignant disease. 59 refs., 7 figs.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PMC&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4426914"><span id="translatedtitle"><span class="hlt">Radiation-induced</span> motility alterations in medulloblastoma cells</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Rieken, Stefan; Rieber, Juliane; Brons, Stephan; Habermehl, Daniel; Rief, Harald; Orschiedt, Lena; Lindel, Katja; Weber, Klaus J.; Debus, Jürgen; Combs, Stephanie E.</p> <p>2015-01-01</p> <p>Photon irradiation has been repeatedly suspected of increasing tumor cell motility and promoting locoregional recurrence of disease. This study was set up to analyse possible mechanisms underlying the potentially <span class="hlt">radiation</span>-altered motility in medulloblastoma cells. Medulloblastoma cell lines D425 and Med8A were analyzed in migration and adhesion experiments with and without photon and carbon ion irradiation. Expression of integrins was determined by quantitative FACS analysis. Matrix metalloproteinase concentrations within cell culture supernatants were investigated by enzyme-linked immunosorbent assay (ELISA). Statistical analysis was performed using Student's t-test. Both photon and carbon ion irradiation significantly reduced chemotactic medulloblastoma cell transmigration through 8-?m pore size membranes, while simultaneously increasing adherence to fibronectin- and collagen I- and IV–coated surfaces. Correspondingly, both photon and carbon ion irradiation downregulate soluble MMP9 concentrations, while upregulating cell surface expression of proadhesive extracellular matrix protein-binding integrin ?5. The observed phenotype of <span class="hlt">radiation</span>-altered motility is more pronounced following carbon ion than photon irradiation. Both photon and (even more so) carbon ion irradiation are effective in inhibiting medulloblastoma cell migration through downregulation of matrix metalloproteinase 9 and upregulation of proadhesive cell surface integrin ?5, which lead to increased cell adherence to extracellular matrix proteins. PMID:25736470</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PUBMED&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/25736470"><span id="translatedtitle"><span class="hlt">Radiation-induced</span> motility alterations in medulloblastoma cells.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rieken, Stefan; Rieber, Juliane; Brons, Stephan; Habermehl, Daniel; Rief, Harald; Orschiedt, Lena; Lindel, Katja; Weber, Klaus J; Debus, Jürgen; Combs, Stephanie E</p> <p>2015-05-01</p> <p>Photon irradiation has been repeatedly suspected of increasing tumor cell motility and promoting locoregional recurrence of disease. This study was set up to analyse possible mechanisms underlying the potentially <span class="hlt">radiation</span>-altered motility in medulloblastoma cells. Medulloblastoma cell lines D425 and Med8A were analyzed in migration and adhesion experiments with and without photon and carbon ion irradiation. Expression of integrins was determined by quantitative FACS analysis. Matrix metalloproteinase concentrations within cell culture supernatants were investigated by enzyme-linked immunosorbent assay (ELISA). Statistical analysis was performed using Student's t-test. Both photon and carbon ion irradiation significantly reduced chemotactic medulloblastoma cell transmigration through 8-?m pore size membranes, while simultaneously increasing adherence to fibronectin- and collagen I- and IV-coated surfaces. Correspondingly, both photon and carbon ion irradiation downregulate soluble MMP9 concentrations, while upregulating cell surface expression of proadhesive extracellular matrix protein-binding integrin ?5. The observed phenotype of <span class="hlt">radiation</span>-altered motility is more pronounced following carbon ion than photon irradiation. Both photon and (even more so) carbon ion irradiation are effective in inhibiting medulloblastoma cell migration through downregulation of matrix metalloproteinase 9 and upregulation of proadhesive cell surface integrin ?5, which lead to increased cell adherence to extracellular matrix proteins. PMID:25736470</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/11230972"><span id="translatedtitle">Cell cycle arrest and apoptosis provoked by UV <span class="hlt">radiation-induced</span> DNA damage are transcriptionally highly divergent responses</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Massimiliano Gentile; Leena Latonen; Marikki Laiho</p> <p>2003-01-01</p> <p>DNA damage caused by UV <span class="hlt">radiation</span> initiates cellu- lar recovery mechanisms, which involve activation of DNA damage response pathways, cell cycle arrest and apoptosis. To assess cellular transcriptional responses to UVC-<span class="hlt">induced</span> DNA damage we com- pared time course responses of human skin fibro- blasts to low and high doses of UVC <span class="hlt">radiation</span> known to <span class="hlt">induce</span> a transient cellular replicative arrest</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPA-EIMS&redirectUrl=http://oaspub.epa.gov/eims/eimsapi.dispdetail?deid=60477"><span id="translatedtitle">DETECTION OF LOW DOSE <span class="hlt">RADIATION</span>-AND CHEMICALLY-<span class="hlt">INDUCED</span> DNA DAMAGE USING TEMPERATURE DIFFERENTIAL FLUORESCENCE ASSAYS</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Rapid, sensitive and simple assays for <span class="hlt">radiation</span>- and chemically-<span class="hlt">induced</span> DNA damage can be of significant benefit to a number of fields including <span class="hlt">radiation</span> biology, clinical research, and environmental monitoring. Although temperature-<span class="hlt">induced</span> DNA strand separation has been use...</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/22739813"><span id="translatedtitle">Determination of ?-<span class="hlt">radiation</span> <span class="hlt">induced</span> proudcts in aqueous solutions of tryptophan and synthesis of 4-, 6- and 7-hydroxytryptophan</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Barbara van Wickern; Burkhardt Müller; Thomas Simat; Hans Steinhart</p> <p>1997-01-01</p> <p>A HPLC method with UV and fluorescence detection was developed to determine ?-<span class="hlt">radiation</span> <span class="hlt">induced</span> products in aqueous solutions of tryptophan. Therefore 4-, 6- and 7-hydroxytryptophan were synthesized in purities which allow their use as reference substances for analytical studies. Oxindolylalanine, N-formylkynurenine, 4-, 5, 6- and 7-hydroxytryptophan were determined as the main <span class="hlt">radiation</span> <span class="hlt">induced</span> products.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PUBMED&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/18853399"><span id="translatedtitle">Mint oil (Mentha spicata Linn.) offers behavioral radioprotection: a <span class="hlt">radiation-induced</span> conditioned taste aversion study.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Haksar, A; Sharma, A; Chawla, R; Kumar, Raj; Lahiri, S S; Islam, F; Arora, M P; Sharma, R K; Tripathi, R P; Arora, Rajesh</p> <p>2009-02-01</p> <p>Mentha spicata Linn. (mint), a herb well known for its gastroprotective properties in the traditional system of medicine has been shown to protect against <span class="hlt">radiation-induced</span> lethality, and recently its constituents have been found to possess calcium channel antagonizing properties. The present study examined the behavioral radioprotective efficacy of mint oil (obtained from Mentha spicata), particularly in mitigating <span class="hlt">radiation-induced</span> conditioned taste aversion (CTA), which has been proposed as a behavioral endpoint that is mediated by the toxic effects of gamma <span class="hlt">radiation</span> on peripheral systems, primarily the gastrointestinal system in the Sprague-Dawley rat model. Intraperitoneal administration of Mentha spicata oil 10% (v/v), 1 h before 2 Gy gamma <span class="hlt">radiation</span>, was found to render significant radioprotection against CTA (p < 0.05), by blocking the saccharin avoidance response within 5 post-treatment observational days, with the highest saccharin intake being observed on day 5. This finding clearly demonstrates that gastroprotective and calcium channel antagonizing properties of Mentha spicata can be effectively utilized in preventing <span class="hlt">radiation-induced</span> behavioral changes. PMID:18853399</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PMC&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4013650"><span id="translatedtitle"><span class="hlt">Radiation-Induced</span> Changes in Serum Lipidome of Head and Neck Cancer Patients</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Jelonek, Karol; Pietrowska, Monika; Ros, Malgorzata; Zagdanski, Adam; Suchwalko, Agnieszka; Polanska, Joanna; Marczyk, Michal; Rutkowski, Tomasz; Skladowski, Krzysztof; Clench, Malcolm R.; Widlak, Piotr</p> <p>2014-01-01</p> <p>Cancer radiotherapy (RT) <span class="hlt">induces</span> response of the whole patient’s body that could be detected at the blood level. We aimed to identify changes <span class="hlt">induced</span> in serum lipidome during RT and characterize their association with doses and volumes of irradiated tissue. Sixty-six patients treated with conformal RT because of head and neck cancer were enrolled in the study. Blood samples were collected before, during and about one month after the end of RT. Lipid extracts were analyzed using MALDI-oa-ToF mass spectrometry in positive ionization mode. The major changes were observed when pre-treatment and within-treatment samples were compared. Levels of several identified phosphatidylcholines, including (PC34), (PC36) and (PC38) variants, and lysophosphatidylcholines, including (LPC16) and (LPC18) variants, were first significantly decreased and then increased in post-treatment samples. Intensities of changes were correlated with doses of <span class="hlt">radiation</span> received by patients. Of note, such correlations were more frequent when low-to-medium doses of <span class="hlt">radiation</span> delivered during conformal RT to large volumes of normal tissues were analyzed. Additionally, some <span class="hlt">radiation-induced</span> changes in serum lipidome were associated with toxicity of the treatment. Obtained results indicated the involvement of choline-related signaling and potential biological importance of exposure to clinically low/medium doses of <span class="hlt">radiation</span> in patient’s body response to <span class="hlt">radiation</span>. PMID:24747595</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PMC&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3464765"><span id="translatedtitle">A gene expression signature distinguishes normal tissues of sporadic and <span class="hlt">radiation-induced</span> papillary thyroid carcinomas</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Dom, G; Tarabichi, M; Unger, K; Thomas, G; Oczko-Wojciechowska, M; Bogdanova, T; Jarzab, B; Dumont, J E; Detours, V; Maenhaut, C</p> <p>2012-01-01</p> <p>Background: Papillary thyroid cancer (PTC) incidence increased dramatically in children after the Chernobyl accident, providing a unique opportunity to investigate the molecular features of <span class="hlt">radiation-induced</span> thyroid cancer. In contrast to the previous studies that included age-related confounding factors, we investigated mRNA expression in PTC and in the normal contralateral tissues of patients exposed and non-exposed to the Chernobyl fallout, using age- and ethnicity-matched non-irradiated cohorts. Methods: Forty-five patients were analysed by full-genome mRNA microarrays. Twenty-two patients have been exposed to the Chernobyl fallout; 23 others were age-matched and resident in the same regions of Ukraine, but were born after 1 March 1987, that is, were not exposed to 131I. Results: A gene expression signature of 793 probes corresponding to 403 genes that permitted differentiation between normal tissues from patients exposed and from those who were not exposed to <span class="hlt">radiation</span> was identified. The differences were confirmed by quantitative RT-PCR. Many deregulated pathways in the exposed normal tissues are related to cell proliferation. Conclusion: Our results suggest that a higher proliferation rate in normal thyroid could be related to <span class="hlt">radiation-induced</span> cancer either as a predisposition or as a consequence of <span class="hlt">radiation</span>. The signature allows the identification of <span class="hlt">radiation-induced</span> thyroid cancers. PMID:22828612</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PMC&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3560832"><span id="translatedtitle">Hydrogen-rich saline protects immunocytes from <span class="hlt">radiation-induced</span> apoptosis</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Yang, Yanyong; Li, Bailong; Liu, Cong; Chuai, Yunhai; Lei, Jixiao; Gao, Fu; Cui, Jianguo; Sun, Ding; Cheng, Ying; Zhou, Chuanfeng; Cai, Jianming</p> <p>2012-01-01</p> <p>Summary Background <span class="hlt">Radiation</span> often causes depletion of immunocytes in tissues and blood, which results in immunosuppression. Molecular hydrogen (H2) has been shown in recent studies to have potential as a safe and effective radioprotective agent through scavenging free radicals. This study was designed to test the hypothesis that H2 could protect immunocytes from ionizing <span class="hlt">radiation</span> (IR). Material/Methods H2 was dissolved in physiological saline or medium using an apparatus produced by our department. A 2-[6-(4?-hydroxy) phenoxy-3H-xanthen-3-on-9-yl] benzoate (HPF) probe was used to detect intracellular hydroxyl radicals (•OH). Cell apoptosis was evaluated by annexin V-FITC and Propidium iodide (PI) staining as well as the caspase 3 activity. Finally, we examined the hematological changes using an automatic Sysmex XE 2100 hematology analyzer. Results We demonstrated H2-rich medium pretreatment reduced •OH level in AHH-1 cells. We also showed H2 reduced <span class="hlt">radiation-induced</span> apoptosis in thymocytes and splenocytes in living mice. <span class="hlt">Radiation-induced</span> caspase 3 activation was also attenuated by H2 treatment. Finally, we found that H2 rescued the <span class="hlt">radiation</span>-caused depletion of white blood cells (WBC) and platelets (PLT). Conclusions This study suggests that H2 protected the immune system and alleviated the hematological injury <span class="hlt">induced</span> by IR. PMID:22460088</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2011SPIE.8119E..0MS"><span id="translatedtitle">Tunable terahertz <span class="hlt">radiation</span> from an ultrashort-laser-pulse-<span class="hlt">induced</span> discharge in biased air</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Suzuki, Fuminori; Anno-Kashiwazaki, Hiroaki; Miyazawa, Jun; Ono, Shohei; Higashiguchi, Takeshi; Yugami, Noboru; Sentoku, Yasuhiko; Kodama, Ryosuke; Muggli, Patric</p> <p>2011-10-01</p> <p>Strong beams of coherent <span class="hlt">radiation</span> are essential to <span class="hlt">induce</span> nonlinear excitation phenomena in biology and material sciences. Optical-field-<span class="hlt">induced</span> ionization by an ultrashort laser pulse produces ultrabroadband bursts of <span class="hlt">radiation</span> with photon energies ranging from radio-wave at the microsecond timescale to x-ray at the attosecond timescale. As the laser pulse drives an ultrafast-discharge with high current it <span class="hlt">induces</span> nonlinear spectral conversion in a few femtoseconds and generates terahertz electromagnetic waves. Broadband terahertz generation has been reported in air and rare gases. If the <span class="hlt">radiation</span> frequency depends on the electron plasma density, it should vary with the laser pulse intensity, and the kind and density of the gas. However, the peak <span class="hlt">radiation</span> frequencies reported are almost independent of those parameters. From the laser-gas interaction point of view, the terahertz generation mechanism is not enough understood. We demonstrate a frequency-tuning scheme that uses the laser pulse duration to control the ultrafast-discharge current timescale, yielding a terahertz energy of 0.1 ?J and a conversion efficiency of 10-4 by use of the homemade power supply with 60-A discharge current at 1 kHz. We also propose a simple physical model to explain the generation of terahertz <span class="hlt">radiation</span> with the laser propagation in an ultrafast-discharge.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/49128220"><span id="translatedtitle">Stretching-<span class="hlt">induced</span> <span class="hlt">crystallinity</span> and orientation of polylactic acid nanofibers with improved mechanical properties using an electrically charged rotating viscoelastic jet</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Chia-Chun Liao; Cheng-Chien Wang; Chuh-Yung Chen</p> <p>2011-01-01</p> <p>An electrospinning technique with an additional centrifugal field was employed to prepare polylactic acid (PLA) nanofibers. The results indicated that combining the strong stretching force of the additional centrifugal field and an electrostatic field can align the PLA polymer chains parallel to the nanofiber axis, producing PLA nanofibers with superior <span class="hlt">crystalline</span> features, molecular orientation and conformation as well as good</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/5406971"><span id="translatedtitle">Base substitutions, frameshifts, and small deletions constitute ionizing <span class="hlt">radiation-induced</span> point mutations in mammalian cells</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Grosovsky, A.J.; de Boer, J.G.; de Jong, P.J.; Drobetsky, E.A.; Glickman, B.W.</p> <p>1988-01-01</p> <p>The relative role of point mutations and large genomic rearrangements in ionizing <span class="hlt">radiation-induced</span> mutagenesis has been an issue of long-standing interest. Recent studies using Southern blotting analysis permit the partitioning of ionizing <span class="hlt">radiation-induced</span> mutagenesis in mammalian cells into detectable deletions and major genomic rearrangements and into point mutations. The molecular nature of these point mutations has been left unresolved; they may include base substitutions as well as small deletions, insertions, and frame-shifts below the level of resolution of Southern blotting analysis. In this investigation, we have characterized a collection of ionizing <span class="hlt">radiation-induced</span> point mutations at the endogenous adenine phosphoribosyltransferase (aprt) locus of Chinese hamster ovary cells at the DNA sequence level. Base substitutions represented approximately equal to 2/3 of the point mutations analyzed. Although the collection of mutants is relatively small, every possible type of base substitution event has been recovered. These mutations are well distributed throughout the coding sequence with only one multiple occurrence. Small deletions represented the remainder of characterized mutants; no insertions have been observed. Sequence-directed mechanisms mediated by direct repeats could account for some of the observed deletions, while others appear to be directly attributable to <span class="hlt">radiation-induced</span> strand breakage.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/1600927"><span id="translatedtitle">Noise characteristics of <span class="hlt">radiation-induced</span> soft breakdown current in ultrathin gate oxides</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Andrea Cester; Leonardo Bandiera; Marco Ceschia; Gabriella Ghidini; Alessandro Paccagnella</p> <p>2001-01-01</p> <p>We have investigated new aspects of the gate leakage current due to <span class="hlt">radiation-induced</span> soft breakdown (RSB) of thin oxides subjected to heavy-ion irradiation. Temperature and noise characteristics of RSB on MOS capacitors with 3- and 4- nm MOS oxides have been experimentally investigated. We have developed an empirical law to describe quantitatively the temperature dependence of the RSB current. A</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/29153588"><span id="translatedtitle">UV <span class="hlt">Radiation-Induced</span> Immunosuppression Is Greater in Men and Prevented by Topical Nicotinamide</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Diona L Damian; Clare R S Patterson; Michael Stapelberg; Ross St C Barnetson; Gary M Halliday</p> <p>2008-01-01</p> <p>UV <span class="hlt">radiation-induced</span> immunosuppression augments cutaneous carcinogenesis. The incidence of skin cancer continues to increase despite increased use of sunscreens, which are less effective at preventing immunosuppression than sunburn. Using the Mantoux reaction as a model of skin immunity, we investigated the effects of solar-simulated (ss) UV and its component UVA and UVB wavebands and tested the ability of topical nicotinamide</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://www.aps.anl.gov/Science/Publications/lsnotes/content/files/APS_1418223.pdf"><span id="translatedtitle"><span class="hlt">Radiation-Induced</span> Demagnetization of Nd-Fe-B Permanent Magnets</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Kemner, Ken</p> <p></p> <p>Operations Division Advanced Photon Source Argonne National Laboratory R.C. Martin, C.M. Simmons, and G Source Argonne National Laboratory R.C. Martin, C.M. Simmons, and G. D. Owen Californium User FacilityLS-290 <span class="hlt">Radiation-Induced</span> Demagnetization of Nd-Fe-B Permanent Magnets J. Alderman and P.K. Job APS</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://www.physik.uni-regensburg.de/forschung/ganichev/reprints/Drexler_APL.pdf"><span id="translatedtitle">Spin polarized electric currents in semiconductor heterostructures <span class="hlt">induced</span> by microwave <span class="hlt">radiation</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Ganichev, Sergey</p> <p></p> <p>Spin polarized electric currents in semiconductor heterostructures <span class="hlt">induced</span> by microwave <span class="hlt">radiation</span> C oscillations in the resistivity of a two-dimensional electron gas 2DEG at- tracted growing attention and a split-coil superconducting magnet yielding a field By 110 with a strength up t</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PMC&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2714242"><span id="translatedtitle">Mitochondrial dysfunction resulting from loss of cytochrome c impairs <span class="hlt">radiation-induced</span> bystander effect</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Yang, G; Wu, L; Chen, S; Zhu, L; Huang, P; Tong, L; Zhao, Y; Zhao, G; Wang, J; Mei, T; Xu, A; Wang, Y</p> <p>2009-01-01</p> <p>Cytochrome c is a pivotal protein that resides in mitochondria as component of mitochondria respiration and apoptosis initiator. Using murine cells lacking cytochrome c, we showed here that cytochrome c-deficient cells had attenuated reactive oxygen species/nitric oxide and micronuclei induction to <span class="hlt">radiation-induced</span> bystander signals, indicating cytochrome c is essential for the bystander effect. PMID:19455142</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://www.eecs.berkeley.edu/~jbokor/Full_text_pubs/20-155.original.pdf"><span id="translatedtitle">At-wavelength characterization of UV-<span class="hlt">radiation-induced</span> damage in fused silica</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Bokor, Jeffrey</p> <p></p> <p>At-wavelength characterization of UV-<span class="hlt">radiation-induced</span> damage in fused silica Sang Hun Lee*1 ABSTRACT Fused silica is the optical material of choice for deep ultraviolet (DUV) lithographic systems report direct, at-wavelength, wavefront measurements of DUV-laser-damaged fused silica samples performed</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/40886607"><span id="translatedtitle">Ambient ultraviolet <span class="hlt">radiation</span> <span class="hlt">induces</span> protective responses in soybean but does not attenuate indirect defense</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Thorsten R. Winter; Michael Rostás</p> <p>2008-01-01</p> <p>We investigated the effects of ambient ultraviolet (UV) <span class="hlt">radiation</span> on (i) the performance and chemistry of soybean plants, (ii) the performance of Spodoptera frugiperda and (iii) the foraging behavior of the herbivore's natural enemy Cotesia marginiventris which exploits herbivore-<span class="hlt">induced</span> plant volatiles (VOC) for host location. The accumulation of protective phenolics was faster in plants receiving ambient UV than in controls</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2013EPJWC..4102030C"><span id="translatedtitle">Intra-cluster dynamics <span class="hlt">induced</span> in molecular clusters by femtosecond UV <span class="hlt">radiation</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chekalin, Sergey V.; Kompanets, Victor O.; Apatin, Valentin M.; Ogurok, Danil D.; Lokhman, Valery N.; Poydashev, Denis G.; Ryabov, Evgeny A.</p> <p>2013-03-01</p> <p>Dynamics of intra-cluster processes <span class="hlt">induced</span> by femtosecond UV laser <span class="hlt">radiation</span> in molecular clusters of CF3I and ICF2COF molecules is studied. The measured time constants of the observed reactions are within the range from 1 ps to dozens of picoseconds.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/437591"><span id="translatedtitle">Use of iron colloid-enhanced MRI for study of acute <span class="hlt">radiation-induced</span> hepatic injury</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Suto, Yuji; Ametani, Masaki; Kato, Takashi; Hashimoto, Masayuki; Kamba, Masayuki; Sugihara, Syuji; Ohta, Yoshio [Tottori Univ. School of Medicine, Yonago (Japan)] [Tottori Univ. School of Medicine, Yonago (Japan)</p> <p>1996-03-01</p> <p>We present a case with acute <span class="hlt">radiation-induced</span> hepatic injury using chondroitin sulfate iron colloid (CSIC)-enhanced MRI. Uptake of CSIC was decreased in the irradiated portion of the liver. CSIC-enhanced MRI is useful for obtaining information on the function of the reticuloendothelial system and demarcates between irradiated and nonirradiated zones. 18 refs., 3 figs</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/30468701"><span id="translatedtitle">Biologic susceptibility of hepatocellular carcinoma patients treated with radiotherapy to <span class="hlt">radiation-induced</span> liver disease</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Jason Chia-Hsien Cheng; Jian-Kuen Wu; Patricia Chiao-Tzu Lee; Hua-Shan Liu; James Jer-Min Jian; Yu-Mong Lin; Juei-Low Sung; Gwo-Jen Jan</p> <p>2004-01-01</p> <p>Purpose:To identify the factors associated with <span class="hlt">radiation-induced</span> liver disease (RILD) and to describe the difference in normal tissue complication probability (NTCP) between subgroups of hepatocellular carcinoma patients undergoing three-dimensional conformal radiotherapy (3D-CRT).</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://cancerres.aacrjournals.org/cgi/reprint/65/8/3100.pdf"><span id="translatedtitle">Influence of Mast Cells on Structural and Functional Manifestations of <span class="hlt">Radiation-Induced</span> Heart Disease</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Marjan Boerma; Junru Wang; Jan Wondergem; Jacob Joseph; Xiaohua Qiu; Richard H. Kennedy; Martin Hauer-Jensen</p> <p>2005-01-01</p> <p><span class="hlt">Radiation-induced</span> heart disease (RIHD), characterized by accelerated atherosclerosis and adverse tissue remodeling, is a serious sequelae after radiotherapy of thoracic and chest wall tumors. Adverse cardiac remodeling in RIHD and other cardiac disorders is frequently accompanied by mast cell hyperplasia, suggesting that mast cells may affect the development of cardiac fibrosis. This study used a mast cell- deficient rat model</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/30393933"><span id="translatedtitle">Oral glutamine to alleviate <span class="hlt">radiation-induced</span> oral mucositis: a pilot randomized trial</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Eng-Yen Huang; Stephen Wan Leung; Chong-Jong Wang; Hui-Chun Chen; Li-Min Sun; Fu-Min Fang; Shyh-An Yeh; Hsuan-Chih Hsu; Ching-Yeh Hsiung</p> <p>2000-01-01</p> <p>Purpose: To evaluate the influence of oral glutamine on <span class="hlt">radiation-induced</span> oral mucositis in the radiotherapy of head and neck cancer.Methods and Materials: From July 1997 through June 1998, 17 patients with head and neck cancer receiving primary or adjuvant irradiation were randomized to either glutamine suspension (16 g in 240 ml normal saline) (n = 8) or placebo (normal saline)</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/21372184"><span id="translatedtitle">Inactivation of Kupffer Cells by Gadolinium Chloride Protects Murine Liver From <span class="hlt">Radiation-Induced</span> Apoptosis</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Du Shisuo; Qiang Min [Department of Radiation Oncology, Zhongshan Hospital, Fudan University, Shanghai (China); Zeng Zhaochong, E-mail: zeng.zhaochong@zs-hospital.sh.c [Department of Radiation Oncology, Zhongshan Hospital, Fudan University, Shanghai (China); Ke Aiwu; Ji Yuan [Liver Cancer Institute, Zhongshan Hospital, Fudan University, Shanghai (China); Zhang Zhengyu [Department of Radiation Oncology, Zhongshan Hospital, Fudan University, Shanghai (China); Zeng Haiying [Department of Pathology, Zhongshan Hospital, Fudan University, Shanghai (China); Liu Zhongshan [Department of Radiation Oncology, Zhongshan Hospital, Fudan University, Shanghai (China)</p> <p>2010-03-15</p> <p>Purpose: To determine whether the inhibition of Kupffer cells before radiotherapy (RT) would protect hepatocytes from <span class="hlt">radiation-induced</span> apoptosis. Materials and Methods: A single 30-Gy fraction was administered to the upper abdomen of Sprague-Dawley rats. The Kupffer cell inhibitor gadolinium chloride (GdCl3; 10 mg/kg body weight) was intravenously injected 24 h before RT. The rats were divided into four groups: group 1, sham RT plus saline (control group); group 2, sham RT plus GdCl3; group 3, RT plus saline; and group 4, RT plus GdCl3. Liver tissue was collected for measurement of apoptotic cytokine expression and evaluation of <span class="hlt">radiation-induced</span> liver toxicity by analysis of liver enzyme activities, hepatocyte micronucleus formation, apoptosis, and histologic staining. Results: The expression of interleukin-1beta, interleukin-6, and tumor necrosis factor-alpha was significantly attenuated in group 4 compared with group 3 at 2, 6, 24, and 48 h after injection (p <0.05). At early points after RT, the rats in group 4 exhibited significantly lower levels of liver enzyme activity, apoptotic response, and hepatocyte micronucleus formation compared with those in group 3. Conclusion: Selective inactivation of Kupffer cells with GdCl3 reduced <span class="hlt">radiation-induced</span> cytokine production and protected the liver against acute <span class="hlt">radiation-induced</span> damage.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/33260342"><span id="translatedtitle">Lysophosphatidic acid protects and rescues intestinal epithelial cells from <span class="hlt">radiation</span>- and chemotherapy-<span class="hlt">induced</span> apoptosis</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Wenlin Deng; Louisa Balazs; Lester Van Middlesworth; Gabor Tigyi; Leonard R. Johnson</p> <p>2002-01-01</p> <p>Background & Aims: We have investigated whether the phospholipid growth factor lysophosphatidic acid (LPA) could prevent intestinal epithelial cells-6 (IEC-6) from apoptosis elicited by 4 different mechanisms. The antiapoptotic effect of LPA was also tested in a mouse model of <span class="hlt">radiation-induced</span> apoptosis. Methods: Apoptosis was elicited by serum withdrawal, exposure to camptothecin, ?-irradiation, or rat tumor necrosis factor alpha and</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/20793434"><span id="translatedtitle">Protection against <span class="hlt">radiation-induced</span> oxidative stress in cultured human epithelial cells by treatment with antioxidant agents</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Wan, X. Steven [Department of Radiation Oncology, University of Pennsylvania School of Medicine, Philadelphia, PA (United States); Ware, Jeffrey H. [Department of Radiation Oncology, University of Pennsylvania School of Medicine, Philadelphia, PA (United States); Zhou, Zhaozong [Department of Radiation Oncology, University of Pennsylvania School of Medicine, Philadelphia, PA (United States); Donahue, Jeremiah J. [Department of Radiation Oncology, University of Pennsylvania School of Medicine, Philadelphia, PA (United States); Guan, Jun [Department of Radiation Oncology, University of Pennsylvania School of Medicine, Philadelphia, PA (United States); Kennedy, Ann R. [Department of Radiation Oncology, University of Pennsylvania School of Medicine, Philadelphia, PA (United States)]. E-mail: akennedy@mail.med.upenn.edu</p> <p>2006-04-01</p> <p>Purpose: To evaluate the protective effects of antioxidant agents against space <span class="hlt">radiation-induced</span> oxidative stress in cultured human epithelial cells. Methods and Materials: The effects of selected concentrations of N-acetylcysteine, ascorbic acid, sodium ascorbate, co-enzyme Q10, {alpha}-lipoic acid, L-selenomethionine, and vitamin E succinate on <span class="hlt">radiation-induced</span> oxidative stress were evaluated in MCF10 human breast epithelial cells exposed to <span class="hlt">radiation</span> with X-rays, {gamma}-rays, protons, or high mass, high atomic number, and high energy particles using a dichlorofluorescein assay. Results: The results demonstrated that these antioxidants are effective in protecting against <span class="hlt">radiation-induced</span> oxidative stress and complete or nearly complete protection was achieved by treating the cells with a combination of these agents before and during the <span class="hlt">radiation</span> exposure. Conclusion: The combination of antioxidants evaluated in this study is likely be a promising countermeasure for protection against space <span class="hlt">radiation-induced</span> adverse biologic effects.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2014cosp...40E3790Z"><span id="translatedtitle">Heavy-ion <span class="hlt">radiation</span> <span class="hlt">induced</span> Photosynthesis changes in Oryza sativa L.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, Meng; Sun, Yeqing; Li, Xishan; Meng, Qingmei</p> <p></p> <p>The abnormal development of rice was observed frequently after the seed was exposed to heavy-ion <span class="hlt">radiation</span>. The heavy-ion <span class="hlt">radiation</span> could change the chloroplast structure in mesophyll cell by decreasing chloroplast grana and loosing the thylakoid lamellas. To study the mechanism of heavy-ion <span class="hlt">radiation</span> <span class="hlt">induced</span> photosynthesis changes, rice seed was exposed to 0-20 Gy dose of (12) C <span class="hlt">radiation</span>. By measuring the changes of chlorophyll fluorescence parameters, the content of chlorophyll as well as the expression of CP24 in the leaves of rice at the three-leaf stage, we analyzed the influence mechanism of heavy-ion <span class="hlt">radiation</span> on photosynthesis in rice. The results indicated that chlorophyll fluorescence parameter Fv/Fm and content of chlorophyll (including chlorophyll a, chlorophyll b and total chlorophyll) changed significantly in different doses. Both the relative expression of CP24 and its encoding gene lhcb6 altered after exposed to different dose of <span class="hlt">radiation</span>. By using Pearson correlation analysis, we found that the 1 Gy was the bound of low-dose <span class="hlt">radiation</span>. The possible molecular mechanisms and biological consequences of the observed changes are discussed. Key Words: Heavy-ion <span class="hlt">Radiation</span>; Rice; Photosynthesis; Fv/Fm; CP24.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PUBMED&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/16668504"><span id="translatedtitle">Physiology of Hormone Autonomous Tissue Lines Derived From <span class="hlt">Radiation-Induced</span> Tumors of Arabidopsis thaliana.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Campell, B R; Town, C D</p> <p>1991-11-01</p> <p>gamma-<span class="hlt">Radiation-induced</span> tumors of Arabidopsis thaliana L. have been produced as a novel approach to isolation of genes that regulate plant development. Tumors excised from irradiated plants are hormone autonomous in culture and have been maintained on hormone-free medium for up to 4 years. Five tumor tissue lines having different morphologies and growth rates were analyzed for auxin, cytokinin, and 1-aminocyclopropane-1-carboxylic acid (ACC) content, ethylene production, and response to exogenous growth regulators. Normal tissues and two crown gall tissue lines were analyzed for comparison. Rosettes and whole seedlings each contained approximately 30 nanograms. (gram fresh weight)(-1) free indoleacetic acid (IAA), 150 nanograms. (gram fresh weight)(-1) ester-conjugated IAA, and 10 to 20 micrograms. (gram fresh weight)(-1) amide-conjugated IAA. The crown gall lines contained similar amounts of free and ester-conjugated IAA but less amide conjugates. Whereas three of the <span class="hlt">radiation-induced</span> tumor lines had IAA profiles similar to normal tissues, one line had 10- to 100-fold more free IAA and three- to 10-fold less amide-conjugated IAA. The fifth line had normal free IAA levels but more conjugated IAA than control tissues. Whole seedlings contained approximately 2 nanograms. (gram fresh weight)(-1) of both zeatin riboside and isopentenyladenosine. The crown gall lines had 100- to 1000-fold higher levels of each cytokinin. In contrast, the three <span class="hlt">radiation-induced</span> tumor lines analyzed contained cytokinin levels similar to the control tissue. The <span class="hlt">radiation-induced</span> tumor tissues produced very little ethylene, although each contained relatively high levels of ACC. Normal callus contained similar amounts of ACC but produced several times more ethylene than the <span class="hlt">radiation-induced</span> tumor lines. Each of the <span class="hlt">radiation-induced</span> tumor tissues displayed a unique set of responses to exogenously supplied growth regulators. Only one tumor line showed the same response as normal callus to both auxin and cytokinin feeding. In some cases, one or more tumor lines showed increased sensitivity to certain growth substances. In other cases, growth regulator feeding had no significant effect on tumor tissue growth. Morphology of the <span class="hlt">radiation-induced</span> tumor tissues generally did not correlate with auxin to cytokinin ratio in the expected manner. The results suggest that a different primary genetic event led to the formation of each tumor and that growth and differentiation in the tumor tissue lines are uncoupled from the normal hormonal controls. PMID:16668504</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/20698439"><span id="translatedtitle">Molecular targets in <span class="hlt">radiation-induced</span> blood-brain barrier disruption</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Nordal, Robert A. [Departments of Radiation Oncology and Medical Biophysics, Sunnybrook and Women's College Health Sciences Centre, University of Toronto, Toronto, Ontario (Canada); Wong, C. Shun [Departments of Radiation Oncology and Medical Biophysics, Sunnybrook and Women's College Health Sciences Centre, University of Toronto, Toronto, Ontario (Canada)]. E-mail: shun.wang@sw.ca</p> <p>2005-05-01</p> <p>Disruption of the blood-brain barrier (BBB) is a key feature of <span class="hlt">radiation</span> injury to the central nervous system. Studies suggest that endothelial cell apoptosis, gene expression changes, and alteration of the microenvironment are important in initiation and progression of injury. Although substantial effort has been directed at understanding the impact of <span class="hlt">radiation</span> on endothelial cells and oligodendrocytes, growing evidence suggests that other cell types, including astrocytes, are important in responses that include <span class="hlt">induced</span> gene expression and microenvironmental changes. Endothelial apoptosis is important in early BBB disruption. Hypoxia and oxidative stress in the later period that precedes tissue damage might lead to astrocytic responses that impact cell survival and cell interactions. Cell death, gene expression changes, and a toxic microenvironment can be viewed as interacting elements in a model of <span class="hlt">radiation-induced</span> disruption of the BBB. These processes implicate particular genes and proteins as targets in potential strategies for neuroprotection.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/22278131"><span id="translatedtitle">Charge trapping in aligned single-walled carbon nanotube arrays <span class="hlt">induced</span> by ionizing <span class="hlt">radiation</span> exposure</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Esqueda, Ivan S., E-mail: isanchez@isi.edu [Information Sciences Institute, University of Southern California, Arlington, Virginia 22203 (United States); Cress, Cory D. [Electronics Science and Technology Division, Naval Research Laboratory, Washington, DC 20375 (United States); Che, Yuchi; Cao, Yu; Zhou, Chongwu [Department of Electrical Engineering, University of Southern California, Los Angeles, California 90089 (United States)</p> <p>2014-02-07</p> <p>The effects of near-interfacial trapping <span class="hlt">induced</span> by ionizing <span class="hlt">radiation</span> exposure of aligned single-walled carbon nanotube (SWCNT) arrays are investigated via measurements of gate hysteresis in the transfer characteristics of aligned SWCNT field-effect transistors. Gate hysteresis is attributed to charge injection (i.e., trapping) from the SWCNTs into <span class="hlt">radiation-induced</span> traps in regions near the SWCNT/dielectric interface. Self-consistent calculations of surface-potential, carrier density, and trapped charge are used to describe hysteresis as a function of ionizing <span class="hlt">radiation</span> exposure. Hysteresis width (h) and its dependence on gate sweep range are investigated analytically. The effects of non-uniform trap energy distributions on the relationship between hysteresis, gate sweep range, and total ionizing dose are demonstrated with simulations and verified experimentally.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/6989745"><span id="translatedtitle">Hyperbaric oxygen in the treatment of <span class="hlt">radiation-induced</span> optic neuropathy</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Guy, J.; Schatz, N.J.</p> <p>1986-08-01</p> <p>Four patients with <span class="hlt">radiation-induced</span> optic neuropathies were treated with hyperbaric oxygen. They had received <span class="hlt">radiation</span> therapy for treatment of pituitary tumors, reticulum cell sarcoma, and meningioma. Two presented with amaurosis fugax before the onset of unilateral visual loss and began hyperbaria within 72 hours after development of unilateral optic neuropathy. Both had return of visual function to baseline levels. The others initiated treatment two to six weeks after visual loss occurred in the second eye and had no significant improvement of vision. Treatment consisted of daily administration of 100% oxygen under 2.8 atmospheres of pressure for 14-28 days. There were no medical complications of hyperbaria. While hyperbaric oxygen is effective in the treatment of <span class="hlt">radiation-induced</span> optic neuropathy, it must be instituted within several days of deterioration in vision for restoration of baseline function.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2004SPIE.5554...59C"><span id="translatedtitle">ESR investigations on <span class="hlt">radiation-induced</span> modifications of irradiated thin polymeric films</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chipara, Mircea; Edwards, David L.; Beezhold, Wendland; Chipara, Magdalena; Nehls, Mary</p> <p>2004-10-01</p> <p>A parallel analysis of <span class="hlt">radiation-induced</span> and thermal-<span class="hlt">induced</span> degradation of polyethyleneterephtalate (PET) films is presented. The complexity of the degradation process is analyzed as a first step in a better understanding of the effect of combined temperature and <span class="hlt">radiation</span> on PET. electron spin resonance spectrometry, DC electrical measurements, differential scanning calorimetry, and mechanical tests were used to analysze the effect of different ioninzing <span class="hlt">radiation</span> (such as gamma, electrons, and accelerated ions) on thin films of PET. Data on the thermal analysis of PET are presented and analyzed. This study aims to a better understanding and modeling of complex degradation processes, required for a more reliable assessment of the behavior of polymers subjected to the space environment.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/5779489"><span id="translatedtitle"><span class="hlt">Radiation-induced</span> lipid peroxidation and the fluidity of erythrocyte membrane lipids</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Guille, J.; Raison, J.K.; Gebicki, J.M.</p> <p>1987-01-01</p> <p>The effect of <span class="hlt">radiation-induced</span> peroxidation on the fluidity of the phospholipids of the erythrocyte membrane was studied using both erythrocyte ghosts and liposomes formed from the polar lipids of erythrocytes. In liposomes, the oxidation of the phospholipids increased with <span class="hlt">radiation</span> dose, but there was no change in the fluidity of the lipids as measured by spin-label motion. Under the same conditions of irradiation, no oxidation of phospholipid was detected in erythrocyte ghosts, although changes occurred in the motion of spin labels intercalated with the membrane. These changes were attributed to <span class="hlt">radiation-induced</span> alterations in the membrane proteins. It is concluded that alterations in motion of spin labels, observed with intact membranes after irradiation, are most likely the result of changes in the structure of membrane proteins rather than the lipids.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PMC&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3066623"><span id="translatedtitle">Large-Scale Binding of ?-<span class="hlt">Crystallin</span> to Cell Membranes of Aged Normal Human Lenses: A Phenomenon That Can Be <span class="hlt">Induced</span> by Mild Thermal Stress</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Friedrich, Michael G.</p> <p>2010-01-01</p> <p>Purpose. With age, large amounts of <span class="hlt">crystallins</span> become associated with fiber cell membranes in the human lens nucleus, and it has been proposed that this binding of protein may lead to the obstruction of membrane pores and the onset of a barrier to diffusion. This study focused on membrane binding within the barrier region and the outermost lens cortex. Methods. Human lenses across the age range were used, and the interaction of <span class="hlt">crystallins</span> with membranes was examined using sucrose density gradient centrifugation, two-dimensional gel electrophoresis, and amine-reactive isobaric tagging technology. Lipids were quantified using shotgun lipidemics. Results. Binding of proteins to cell membranes in the barrier region was found to be different from that in the lens nucleus because in the barrier and outer cortical regions, only one high-density band formed. Most of the membrane-associated protein in this high-density band was ?-<span class="hlt">crystallin</span>. Mild thermal stress of intact young lenses led to pronounced membrane binding of proteins and yielded a sucrose density pattern in all lens regions that appeared to be identical with that from older lenses. Conclusions. ?-<span class="hlt">Crystallin</span> is the major protein that binds to cell membranes in the barrier region of lenses after middle age. Exposure of young human lenses to mild thermal stress results in large-scale binding of ?-<span class="hlt">crystallin</span> to cell membranes. The density gradient profiles of such heated lenses appear to be indistinguishable from those of older normal lenses. The data support the hypothesis that temperature may be a factor responsible for age-related changes to the human lens. PMID:20435594</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2005REDS..160..145I"><span id="translatedtitle"><span class="hlt">Radiation-induced</span> changes in GMA-AMPS copolymer</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Indira, S.; Rao, B. S.; Sridhar, V.; Punnaiah, G.</p> <p>2005-03-01</p> <p>Changes that occurred on gamma irradiation of guanidine methyl methacrylate 2-acrylamido-2-methyl- 2-propane sulphonic acid(GMA-AMPS) copolymer have been investigated by the electron spin resonance (ESR) and Fourier transform infrared (FTIR) spectroscopy. The ESR spectrum observed for gamma irradiated GMA-AMPS copolymer is a sextet spectrum with a hyperfine separation of 20 +/- 1 and 10 +/- 1G. The observed spectrum is simulated to be a superposition of component spectra arising due to macroradicals similar to CH2-(C) over dot H-CH2 similar to, methylene radicals similar to CH2 and radicals of the type RO(O) over dot and/or similar to (C) ovr dot H similar to. Irradiation of the copolymer to higher <span class="hlt">radiation</span> dose has led to the formation of almost the same free radical species. The FTIR spectra of pure and irradiated copolymer have confirmed the earlier-mentioned results.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASA-TRS&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19990009921&hterms=UV+radiation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DUV%2Bradiation"><span id="translatedtitle"><span class="hlt">Radiation</span> <span class="hlt">Induced</span> Degradation of White Thermal Control Paint</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Edwards, D. L.; Zwiener, J. M.; Wertz, G. E.; Vaughn, Jason A.; Kamenetzky, Rachel R.; Finckenor, M. M.; Meshishnek, M. J.</p> <p>1998-01-01</p> <p>This paper details a comparison analysis of the zinc-oxide pigmented white thermal control paints Z-93 and Z-93P. Both paints were simultaneously exposed to combined space environmental effects and analyzed using an in-vacuo reflectance technique. The dose applied to the paints was approximately equivalent to 5 yr in a geosynchronous orbit. This comparison analysis showed that Z-93P is an acceptable substitute for Z-93. Irradiated samples of Z-93 and Z-93P were subjected to additional exposures of ultraviolet (UV) <span class="hlt">radiation</span> and analyzed using the in-vacuo reflectance technique to investigate UV activated reflectance recovery. Both samples showed minimal UV activated reflectance recovery after an additional 190 equivalent Sun hour (ESH) exposure. Reflectance response utilizing nitrogen as a repressurizing gas instead of air was also investigated. This investigation found the rates of reflectance recovery when repressurized with nitrogen are slower than when repressurized with air.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASA-TRS&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19990093197&hterms=UV+radiation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DUV%2Bradiation"><span id="translatedtitle"><span class="hlt">Radiation</span> <span class="hlt">Induced</span> Degradation of White Thermal Control Paint</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Edwards, D. L.; Zwiener, J. M.; Wertz, G. E.; Vaughn, J. A.; Kamenetzky, R. R.; Finckenor, M. M.; Meshishnek, M. J.</p> <p>1998-01-01</p> <p>This paper details a comparison analysis of the Zinc Oxide pigmented white thermal control paints Z-93 and Z-93P. Both paints were simultaneously exposed to combined space environmental effects and analyzed using an in-vacuum reflectance technique. The dose applied to the paints was approximately equivalent to 5 years in a geosynchronous orbit. This comparison analysis showed that Z-93P is an acceptable substitute for Z-93. Irradiated samples of Z-93 and Z-93P were subjected to additional exposures of ultraviolet (UV) <span class="hlt">radiation</span> and analyzed using the in-vacuum reflectance technique to investigate UV activated reflectance recovery. Both samples showed minimal UV activated reflectanc6 recovery after an additional 190 Equivalent Sun Hour (ESH) exposure. Reflectance response utilizing nitrogen as a repressurizing gas instead of air was also investigated. This investigation found the rates of reflectance recovery when repressurized with nitrogen are slower than when repressurized with air.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASA-TRS&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19990040482&hterms=UV+radiation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DUV%2Bradiation"><span id="translatedtitle"><span class="hlt">Radiation</span> <span class="hlt">Induced</span> Degradation of White Thermal Control Paint</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Edwards, D. L.; Zwiener, J. M.; Wertz, G. E.; Vaughn, Jason A.; Kamenetzky, Rachel R.; Finckenor, M. M.; Meshishnek, M. J.</p> <p>1999-01-01</p> <p>This paper details a comparison analysis of the zinc-oxide pigmented white thermal control paints Z-93 and Z-93P. Both paints were simultaneously exposed to combined space environmental effects and analyzed using an in-vacuo reflectance technique. The dose applied to the paints was approximately equivalent to 5 yr in a geosynchronous orbit. This comparison analysis showed that Z-93P is an acceptable substitute for Z-93. Irradiated samples of Z-93 and Z-93P were subjected to additional exposures of ultraviolet (UV) <span class="hlt">radiation</span> and analyzed using the in-vacuo reflectance technique to investigate UV activated reflectance recovery. Both samples showed minimal UV activated reflectance recovery after an additional 190 equivalent Sun hour (ESH) exposure. Reflectance response utilizing nitrogen as a repressurizing gas instead of air was also investigated. This investigation found the rates of reflectance recovery when repressurized with nitrogen are slower than when repressurized with air.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_24 --> <div id="page_25" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="481"> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://arxiv.org/pdf/gr-qc/0511001v1"><span id="translatedtitle">A squeezed state source using <span class="hlt">radiation</span> pressure <span class="hlt">induced</span> rigidity</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>T. Corbitt; Y. Chen; F. Khalili; D. Ottaway; S. Vyatchanin; S. Whitcomb; N. Mavalvala</p> <p>2005-11-01</p> <p>We propose an experiment to extract ponderomotive squeezing from an interferometer with high circulating power and low mass mirrors. In this interferometer, optical resonances of the arm cavities are detuned from the laser frequency, creating a mechanical rigidity that dramatically suppresses displacement noise. After taking into account imperfection of optical elements, laser noise, and other technical noise consistent with existing laser and optical technologies and typical laboratory environments, we expect the output light from the interferometer to have measurable squeezing of ~5 dB, with a frequency-independent squeeze angle for frequencies below 1 kHz. This squeeze source is well suited for injection into a gravitational-wave interferometer, leading to improved sensitivity from reduction in the quantum noise. Furthermore, this design provides an experimental test of quantum-limited <span class="hlt">radiation</span> pressure effects, which have not previously been tested.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://arxiv.org/pdf/1307.4704.pdf"><span id="translatedtitle">Galactic cosmic ray <span class="hlt">induced</span> <span class="hlt">radiation</span> dose on terrestrial exoplanets</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Atri, Dimitra; Griessmeier, Jean-Mathias</p> <p>2013-01-01</p> <p>This past decade has seen tremendous advancements in the study of extrasolar planets. Observations are now made with increasing sophistication from both ground and space based instruments, and exoplanets are characterized with increasing precision. There is a class of particularly interesting exoplanets, falling in the habitable zone, which is defined as the area around a star where the planet is capable of supporting liquid water on its surface. Theoretical calculations also suggest that close-in exoplanets are more likely to have weaker planetary magnetic fields, especially in case of super earths. Such exoplanets are subjected to a high flux of Galactic Cosmic Rays (GCRs) due to their weak magnetic moments. GCRs are energetic particles of astrophysical origin, which strike the planetary atmosphere and produce secondary particles, including muons, which are highly penetrating. Some of these particles reach the planetary surface and contribute to the <span class="hlt">radiation</span> dose. Along with the magnetic field, another fac...</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=EPRINT&redirectUrl=http://hal.archives-ouvertes.fr/docs/00/59/17/97/PDF/UVA_base_pairing_effect_revised_manuscript.pdf"><span id="translatedtitle">Base-pairing enhances fluorescence and favors cyclobutane dimer formation <span class="hlt">induced</span> upon absorption of UVA <span class="hlt">radiation</span> by DNA</span></a></p> <p><a target="_blank" href="http://www.osti.gov/eprints/">E-print Network</a></p> <p>Paris-Sud XI, Université de</p> <p></p> <p>that absorption of UV <span class="hlt">radiation</span> by DNA <span class="hlt">induces</span> carcinogenic mutations has triggered numerous studies aiming of UVA <span class="hlt">radiation</span> by DNA Akos Banyasz, Ignacio Vayá, Pascale Changenet-Barret, Thomas Gustavsson, Thierry to the fact that individual DNA bases do not absorb UVA <span class="hlt">radiation</span>. However, a few studies have shown</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/servlets/purl/10162070"><span id="translatedtitle">The role of constitutive and <span class="hlt">inducible</span> processes in the response of human squamous cell carcinoma cell lines to ionizing <span class="hlt">radiation</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Schwartz, J.L.</p> <p>1993-06-01</p> <p>The inherent <span class="hlt">radiation</span> sensitivity of the cells within a tumor is thought to contribute to the success or failure of <span class="hlt">radiation</span> therapy. In vitro studies have shown that <span class="hlt">radiation</span> sensitivity differences in squamous cell carcinoma cell lines reflect alterations in DNA repair. These alterations result from constitutive changes in chromosome organization, not <span class="hlt">radiation-inducible</span> processes. While <span class="hlt">inducible</span> responses may play some role in the <span class="hlt">radiation</span> response of tumor cells, there is no evidence for their involvement in inherent tumor cell radiosensitivity differences or in the success or failure of radiotherapy for squamous cell carcinomas.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PUBMED&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/24517728"><span id="translatedtitle">Bystander effect <span class="hlt">induced</span> by UVC <span class="hlt">radiation</span> in Chinese hamster V79 cells.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wu, Shengwen; Jin, Cuihong; Lu, Xiaobo; Yang, Jinghua; Liu, Qiufang; Qi, Ming; Lu, Shuai; Zhang, Lifeng; Cai, Yuan</p> <p>2014-01-01</p> <p>In past decades, researches on <span class="hlt">radiation-induced</span> bystander effect mainly focused on ionizing <span class="hlt">radiation</span> such as ?-particle, ?-particle, X-ray and ?-ray. But few researches have been conducted on the ability of ultraviolet (UV) <span class="hlt">radiation-induced</span> bystander effect, and knowledge of UVC-<span class="hlt">induced</span> bystander effect is far limited. Here, we adopted medium transfer experiment to detect whether UVC could cause bystander effect in Chinese hamster V79 cells. We determined the cell viability, apoptosis rate, chromosome aberration and ultrastructure changes, respectively. Our results showed that: (1) the viability of UVC-irradiated V79 cells declined significantly with the dosage of UVC; (2) similar to the irradiated cells, the main death type of bystander cells cultured in irradiation conditioned medium (ICMs) was also apoptosis; (3) soluble factors secreted by UVC-irradiated cells could <span class="hlt">induce</span> bystander effect in V79 cells; (4) cells treated with 4 h ICM collected from 90 mJ cm(-2) UVC-irradiated cells displayed the strongest response. Our data revealed that UVC could cause bystander effect through the medium soluble factors excreted from irradiated cells and this bystander effect was a novel quantitative and kinetic response. These findings might provide a foundation to further explore the exact soluble bystander factors and detailed mechanism underlying UVC-<span class="hlt">induced</span> bystander effect. PMID:24517728</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PUBMED&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/25003837"><span id="translatedtitle">Blocking the formation of <span class="hlt">radiation-induced</span> breast cancer stem cells.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Yangyang; Li, Wende; Patel, Shalin S; Cong, Juan; Zhang, Nan; Sabbatino, Francesco; Liu, Xiaoyan; Qi, Yuan; Huang, Peigen; Lee, Hang; Taghian, Alphonse; Li, Jian-Jian; DeLeo, Albert B; Ferrone, Soldano; Epperly, Michael W; Ferrone, Cristina R; Ly, Amy; Brachtel, Elena F; Wang, Xinhui</p> <p>2014-06-15</p> <p>The goal of adjuvant (post-surgery) <span class="hlt">radiation</span> therapy (RT) for breast cancer (BC) is to eliminate residual cancer cells, leading to better local tumor control and thus improving patient survival. However, radioresistance increases the risk of tumor recurrence and negatively affects survival. Recent evidence shows that breast cancer stem cells (BCSCs) are <span class="hlt">radiation</span>-resistant and that relatively differentiated BC cells can be reprogrammed into <span class="hlt">induced</span> BCSCs (iBCSCs) via <span class="hlt">radiation-induced</span> re-expression of the stemness genes. Here we show that in irradiation (IR)-treated mice bearing syngeneic mammary tumors, IR-<span class="hlt">induced</span> stemness correlated with increased spontaneous lung metastasis (51.7%). However, IR-<span class="hlt">induced</span> stemness was blocked by targeting the NF-?B- stemness gene pathway with disulfiram (DSF)and Copper (Cu2+). DSF is an inhibitor of aldehyde dehydrogenase (ALDH) and an FDA-approved drug for treating alcoholism. DSF binds to Cu2+ to form DSF-Cu complexes (DSF/Cu), which act as a potent apoptosis <span class="hlt">inducer</span> and an effective proteasome inhibitor, which, in turn, inhibits NF-?B activation. Treatment of mice with RT and DSF significantly inhibited mammary primary tumor growth (79.4%) and spontaneous lung metastasis (89.6%) compared to vehicle treated mice. This anti-tumor efficacy was associated with decreased stem cell properties (or stemness) in tumors. We expect that these results will spark clinical investigation of RT and DSF as a novel combinatorial treatment for breast cancer. PMID:25003837</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PMC&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4285448"><span id="translatedtitle"><span class="hlt">Radiation-induced</span> Breast Telangiectasias Treated with the Pulsed Dye Laser</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Rossi, Anthony M.; Nehal, Kishwer S.</p> <p>2014-01-01</p> <p>Background and objectives: <span class="hlt">Radiation</span> dermatitis is a frequent sequela of adjuvant <span class="hlt">radiation</span> therapy for breast cancer. Clinical manifestations include prominent telangiectasias that may be physically disfiguring and psychologically distressing for the patient. The objective of this study was to review cases of breast cancer patients with <span class="hlt">radiation-induced</span> breast telangiectasias treated with the pulsed dye laser and assess clinical efficacy. The patient’s perception of treatment was also reviewed. Study design: A retrospective chart review of patients treated for <span class="hlt">radiation-induced</span> telangiectasias was conducted at the Dermatology Division of Memorial Sloan-Kettering Cancer Center. Materials and methods: Pre- and post-clinical photos were used to assess clearance by two independent raters. Patient’s comments were assessed from visit notes and the treating physicians for the impact of treatment on the patient’s overall well-being. Results: All patients (n=11) experienced clinical improvement in the <span class="hlt">radiation-induced</span> telangiectasias. The mean number of treatments was 4.3 (2–9) with an average fluence of 4.2J/cm2 (585nm platform) and 7.8J/cm2 (595nm) (4–8 J/cm2) used. The mean percent clearance was 72.7 percent (50–90%). Adverse effects were not encountered including those with breast implants or flap reconstruction. Patients reported an improvement in their well-being, including an improved sense of confidence. Limitations: Limitations include the small sample size, nonstandardized digital images, and nonsystematic collection of patient-reported outcomes. Conclusion: The pulsed dye laser is an efficacious treatment for <span class="hlt">radiation-induced</span> breast telangiectasias. Multiple treatments are required for greater than 50-percent clearance and conservative treatment parameters are advised. Patients also reported an improved quality of life. PMID:25584136</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/53697346"><span id="translatedtitle">Effects of vacuum-ultraviolet <span class="hlt">radiation</span> on the plasma-<span class="hlt">induced</span> charging of patterned-dielectric materials</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>Ganesh Upadhyaya</p> <p>2008-01-01</p> <p>In this work, the effects of vacuum-ultraviolet (VUV) <span class="hlt">radiation</span> on the plasma-<span class="hlt">induced</span> charging of patterned-dielectric structures are investigated. Experimental results show that supplemental-VUV <span class="hlt">radiation</span> exposure of patterned dielectrics is beneficial in minimizing the plasma-<span class="hlt">induced</span> charge on patterned-dielectric structures. The results of this work indicate that exposure of patterned-dielectric materials to VUV <span class="hlt">radiation</span> during plasma processing can be useful in reducing</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2010AIPC.1267..324Y"><span id="translatedtitle">Evaluation of the Effects of the Ultra-Violet <span class="hlt">Radiation</span> of Antarctica on Bovine Corneas and Lenses by Raman Spectroscopy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yamamoto, Tatsuyuki; Imura, Satoshi; Yamamoto, Naoyuki</p> <p>2010-08-01</p> <p>The Raman spectra of bovine corneas and lenses irradiated to the ultra violet <span class="hlt">radiation</span> at Syowa station of Antarctica were observed. The bovine <span class="hlt">crystallin</span> occurred photo-<span class="hlt">induced</span> cataract by the exposure to the solar <span class="hlt">radiation</span> of mid-summer at Antarctica. Photo-<span class="hlt">induced</span> decrease of Raman signals assigned to Trp residues suggests that the structural change of <span class="hlt">crystallin</span> is correlated with the decomposition of them. The Raman spectra of the collagen of cornea showed little change, however FT-IR measurements showed that the IamideII/IamideI decreased much by the exposure to the solar <span class="hlt">radiation</span> of mid-summer at Antarctica.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2006cosp...36..669G"><span id="translatedtitle">Neurotoxicity of human neural cells <span class="hlt">induced</span> by space <span class="hlt">radiation</span>: in vitro risk assessment and countermeasure</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Guida, P.; Vazquez, M.; Kim, A.</p> <p></p> <p>As the duration of space missions increases the potential for neurological damage to astronauts resulting from exposure to <span class="hlt">radiation</span> also increases To explore the cytotoxic effects of low and high LET <span class="hlt">radiation</span> on cells of the central nervous system we utilized a model in vitro system consisting of a human neuronal progenitor cell line NT2 and its terminally differentiated derivative hNT neurons We found that exposure to numerous forms of ionizing <span class="hlt">radiation</span> <span class="hlt">induced</span> cell detachment necrosis and apoptosis in time dose and LET dependent manners From the slopes of the dose-response curves we calculated RBE values for each form of heavy ion <span class="hlt">radiation</span> A sequential field of 1 GeV n protons and iron ions <span class="hlt">induced</span> apoptosis to a greater extent than either ion alone and the time between hits was also an important determining factor In addition cycling neuronal progenitor cells underwent a dramatic G2 phase specific cell cycle delay within 6 hours following exposure to either low or high LET <span class="hlt">radiation</span> The molecular effects of HZE <span class="hlt">radiation</span> were also investigated with an emphasis on the cell stress response protein p53 Heavy ion <span class="hlt">radiation</span> <span class="hlt">induced</span> expression of p53 in a time and dose dependent manner in both neuronal progenitor and mature neuronal cells Furthermore several post-translational modifications to the p53 protein were detected 2 hours after exposure to gamma rays Experiments incorporating pifithrin- alpha a small molecule inhibitor of p53 suggest that induction of both apoptosis and the cell cycle delay in human NT2 cells is</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PMC&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3980444"><span id="translatedtitle">Ionizing <span class="hlt">radiation-induced</span> metabolic oxidative stress and prolonged cell injury</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Azzam, Edouard I.; Jay-Gerin, Jean-Paul; Pain, Debkumar</p> <p>2013-01-01</p> <p>Cellular exposure to ionizing <span class="hlt">radiation</span> leads to oxidizing events that alter atomic structure through direct interactions of <span class="hlt">radiation</span> with target macromolecules or via products of water radiolysis. Further, the oxidative damage may spread from the targeted to neighboring, non-targeted bystander cells through redox-modulated intercellular communication mechanisms. To cope with the <span class="hlt">induced</span> stress and the changes in the redox environment, organisms elicit transient responses at the molecular, cellular and tissue levels to counteract toxic effects of <span class="hlt">radiation</span>. Metabolic pathways are <span class="hlt">induced</span> during and shortly after the exposure. Depending on <span class="hlt">radiation</span> dose, dose-rate and quality, these protective mechanisms may or may not be sufficient to cope with the stress. When the harmful effects exceed those of homeostatic biochemical processes, <span class="hlt">induced</span> biological changes persist and may be propagated to progeny cells. Physiological levels of reactive oxygen and nitrogen species play critical roles in many cellular functions. In irradiated cells, levels of these reactive species may be increased due to perturbations in oxidative metabolism and chronic inflammatory responses, thereby contributing to the long-term effects of exposure to ionizing <span class="hlt">radiation</span> on genomic stability. Here, in addition to immediate biological effects of water radiolysis on DNA damage, we also discuss the role of mitochondria in the delayed outcomes of ionization <span class="hlt">radiation</span>. Defects in mitochondrial functions lead to accelerated aging and numerous pathological conditions. Different types of <span class="hlt">radiation</span> vary in their linear energy transfer (LET) properties, and we discuss their effects on various aspects of mitochondrial physiology. These include short and long-term in vitro and in vivo effects on mitochondrial DNA, mitochondrial protein import and metabolic and antioxidant enzymes. PMID:22182453</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/20793501"><span id="translatedtitle"><span class="hlt">Radiation-induced</span> liver disease in three-dimensional conformal <span class="hlt">radiation</span> therapy for primary liver carcinoma: The risk factors and hepatic <span class="hlt">radiation</span> tolerance</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Liang Shixiong [Department of Radiation Oncology, Fudan University Cancer Hospital, Shanghai (China); Department of Radiation Oncology, Cancer Hospital, Guangxi Medical University, Nanning (China); Zhu Xiaodong [Department of Radiation Oncology, Cancer Hospital, Guangxi Medical University, Nanning (China); Xu Zhiyong [Department of Radiation Oncology, Fudan University Cancer Hospital, Shanghai (China); Department of Oncology, Shanghai Medical School, Fudan University, Shanghai (China)] (and others)</p> <p>2006-06-01</p> <p>Purpose: To identify risk factors relevant to <span class="hlt">radiation-induced</span> liver disease (RILD) and to determine the hepatic tolerance to <span class="hlt">radiation</span>. Methods and Materials: The data of 109 primary liver carcinomas (PLC) treated with hypofractionated three-dimensional conformal <span class="hlt">radiation</span> therapy (3D-CRT) were analyzed. Seventeen patients were diagnosed with RILD and 13 of 17 died of it. Results: The risk factors for RILD were late T stage, large gross tumor volume, presence of portal vein thrombosis, association with Child-Pugh Grade B cirrhosis, and acute hepatic toxicity. Multivariate analyses demonstrated that the severity of hepatic cirrhosis was a unique independent predictor. For Child-Pugh Grade A patients, the hepatic <span class="hlt">radiation</span> tolerance was as follows: (1) Mean dose to normal liver (MDTNL) of 23 Gy was tolerable. (2) For cumulative dose-volume histogram, the tolerable volume percentages would be less than: V{sub 5} of 86%, V{sub 1} of 68%, V{sub 15} of 59%, V{sub 2} of 49%, V{sub 25} of 35%, V{sub 3} of 28%, V{sub 35} of 25%, and V{sub 4} of 20%. (3) Tolerable MDTNL could be estimated by MDTNL (Gy) = -1.686 + 0.023 * normal liver volume (cm{sup 3}). Conclusion: The predominant risk factor for RILD was the severity of hepatic cirrhosis. The hepatic tolerance to <span class="hlt">radiation</span> could be estimated by dosimetric parameters.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PUBMED&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/24480782"><span id="translatedtitle"><span class="hlt">Radiation-induced</span> immunogenic modulation of tumor enhances antigen processing and calreticulin exposure, resulting in enhanced T-cell killing.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gameiro, Sofia R; Jammeh, Momodou L; Wattenberg, Max M; Tsang, Kwong Y; Ferrone, Soldano; Hodge, James W</p> <p>2014-01-30</p> <p><span class="hlt">Radiation</span> therapy (RT) is used for local tumor control through direct killing of tumor cells. <span class="hlt">Radiation-induced</span> cell death can trigger tumor antigen-specific immune responses, but these are often noncurative. <span class="hlt">Radiation</span> has been demonstrated to <span class="hlt">induce</span> immunogenic modulation (IM) in various tumor types by altering the biology of surviving cells to render them more susceptible to T cell-mediated killing. Little is known about the mechanism(s) underlying IM elicited by sub-lethal <span class="hlt">radiation</span> dosing. We have examined the molecular and immunogenic consequences of <span class="hlt">radiation</span> exposure in breast, lung, and prostate human carcinoma cells. <span class="hlt">Radiation</span> <span class="hlt">induced</span> secretion of ATP and HMGB1 in both dying and surviving tumor cells. In vitro and in vivo tumor irradiation <span class="hlt">induced</span> significant upregulation of multiple components of the antigen-processing machinery and calreticulin cell-surface expression. Augmented CTL lysis specific for several tumor-associated antigens was largely dictated by the presence of calreticulin on the surface of tumor cells and constituted an adaptive response to endoplasmic reticulum stress, mediated by activation of the unfolded protein response. This study provides evidence that <span class="hlt">radiation</span> <span class="hlt">induces</span> a continuum of immunogenic alterations in tumor biology, from immunogenic modulation to immunogenic cell death. We also expand the concept of immunogenic modulation, where surviving tumor cells recovering from <span class="hlt">radiation-induced</span> endoplasmic reticulum stress become more sensitive to CTL killing. These observations offer a rationale for the combined use of <span class="hlt">radiation</span> with immunotherapy, including for patients failing RT alone. PMID:24480782</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASAADS&redirectUrl=http://adsabs.harvard.edu/abs/2011ChPhB..20l8702L"><span id="translatedtitle"><span class="hlt">Radiation-induced</span> robust oscillation and non-Gaussian fluctuation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Bo; Yan, Shi-Wei; Geng, Yi-Zhao</p> <p>2011-12-01</p> <p>There have been many recent studies devoted to the consequences of stochasticity in protein circuitry. Stress conditions, including DNA damage, hypoxia, heat shock, nutrient deprivation, and oncogene activation, can result in the activation and accumulation of p53. Several experimental studies show that oscillations can be <span class="hlt">induced</span> by DNA damage following nuclear irradiation. To explore the underlying dynamical features and the role of stochasticity, we discuss the oscillatory dynamics in the well-studied regulatory network motif. The fluctuations around the fixed point of a delayed system are Gaussian in the limit of sufficiently weak delayed feedback, and remain Gaussian along a limit cycle when viewed tangential to the trajectory. The experimental results are recapitulated in this study. We illustrate several features of the p53 activities, which are robust when the parameters change. Furthermore, the distribution in protein abundance can be characterized by its non-Gaussian nature.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-MAS&redirectUrl=http://academic.research.microsoft.com/Publication/19272270"><span id="translatedtitle">Modeling of Absorption <span class="hlt">Induced</span> by Space <span class="hlt">Radiation</span> on Glass: A Two-Variable Function Depending on <span class="hlt">Radiation</span> Dose and Post-Irradiation Time</span></a></p> <p><a target="_blank" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p>M. Fernandez-Rodriguez; C. G. Alvarado; A. Nunez; A. Alvarez-Herrero</p> <p>2006-01-01</p> <p>NBK7 and FK51 glass from SCHOTT commonly employed on space optical instrumentation design have been gamma irradiated in order to relate the color centers generated by effect of the <span class="hlt">radiation</span> to the changes in their optical properties. The effects of gamma <span class="hlt">radiation</span> on the glass optical properties have been analyzed from transmission measurements and ellipsometric characterization. The absorption bands <span class="hlt">induced</span></p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PUBMED&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/23249859"><span id="translatedtitle">Protective effect of anthocyanins from lingonberry on <span class="hlt">radiation-induced</span> damages.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fan, Zi-Luan; Wang, Zhen-Yu; Zuo, Li-Li; Tian, Shuang-Qi</p> <p>2012-12-01</p> <p>There is a growing concern about the serious harm of radioactive materials, which are widely used in energy production, scientific research, medicine, industry and other areas. In recent years, owing to the great side effects of anti-<span class="hlt">radiation</span> drugs, research on the <span class="hlt">radiation</span> protectants has gradually expanded from the previous chemicals to the use of natural anti-<span class="hlt">radiation</span> drugs and functional foods. Some reports have confirmed that anthocyanins are good antioxidants, which can effectively eliminate free radicals, but studies on the immunoregulatory and anti-<span class="hlt">radiation</span> effects of anthocyanins from lingonberry (ALB) are less reported. In this experiment, mice were given orally once daily for 14 consecutive days before exposure to 6 Gy of gamma-<span class="hlt">radiation</span> and were sacrificed on the 7th day post-irradiation. The results showed that the selected dose of extract did not lead to acute toxicity in mice; while groups given anthocyanins orally were significantly better than <span class="hlt">radiation</span> control group according to blood analysis; pretreatment of anthocyanins significantly (p < 0.05) enhanced the thymus and spleen indices and spleen cell survival compared to the irradiation control group. Pretreatment with anthocyanins before irradiation significantly reduced the numbers of micronuclei (MN) in bone marrow polychromatic erythrocytes (PCEs). These findings indicate that anthocyanins have immunostimulatory potential against immunosuppression <span class="hlt">induced</span> by the <span class="hlt">radiation</span>. PMID:23249859</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/1000434"><span id="translatedtitle">Effects of estrogen and gender on cataractogenesis <span class="hlt">induced</span> by high-LET <span class="hlt">radiation</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Henderson, M.A.; Rusek, A.; Valluri, S.; Garrett, J.; Lopez, J.; Caperell-Grant, A.; Mendonca, M.; Bigsby, R.; Dynlacht, J.</p> <p>2010-02-01</p> <p>Planning for long-duration manned lunar and interplanetary missions requires an understanding of <span class="hlt">radiation-induced</span> cataractogenesis. Previously, it was demonstrated that low-linear energy transfer (LET) irradiation with 10 Gy of {sup 60}Co {gamma} rays resulted in an increased incidence of cataracts in male rats compared to female rats. This gender difference was not due to differences in estrogen, since male rats treated with the major secreted estrogen 17-{beta}-estradiol (E2) showed an identical increase compared to untreated males. We now compare the incidence and rate of progression of cataracts <span class="hlt">induced</span> by high-LET <span class="hlt">radiation</span> in male and female Sprague-Dawley rats. Rats received a single dose of 1 Gy of 600 MeV {sup 56}Fe ions. Lens opacification was measured at 2-4 week intervals with a slit lamp. The incidence and rate of progression of <span class="hlt">radiation-induced</span> cataracts was significantly increased in the animals in which estrogen was available from endogenous or exogenous sources. Male rats with E2 capsules implanted had significantly higher rates of progression compared to male rats with empty capsules implanted (P = 0.025) but not compared to the intact female rats. These results contrast with data obtained after low-LET irradiation and suggest the possibility that the different types of damage caused by high- and low-LET <span class="hlt">radiation</span> may be influenced differentially by steroid sex hormones.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=PUBMED&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/23297316"><span id="translatedtitle">Nature of nontargeted <span class="hlt">radiation</span> effects observed during fractionated irradiation-<span class="hlt">induced</span> thymic lymphomagenesis in mice.</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tsuji, Hideo; Ishii-Ohba, Hiroko; Shiomi, Tadahiro; Shiomi, Naoko; Katsube, Takanori; Mori, Masahiko; Nenoi, Mitsuru; Ohno, Mizuki; Yoshimura, Daisuke; Oka, Sugako; Nakabeppu, Yusaku; Tatsumi, Kouichi; Muto, Masahiro; Sado, Toshihiko</p> <p>2013-05-01</p> <p>Changes in the thymic microenvironment lead to <span class="hlt">radiation-induced</span> thymic lymphomagenesis, but the phenomena are not fully understood. Here we show that <span class="hlt">radiation-induced</span> chromosomal instability and bystander effects occur in thymocytes and are involved in lymphomagenesis in C57BL/6 mice that have been irradiated four times with 1.8-Gy ?-rays. Reactive oxygen species (ROS) were generated in descendants of irradiated thymocytes during recovery from <span class="hlt">radiation-induced</span> thymic atrophy. Concomitantly, descendants of irradiated thymocytes manifested DNA lesions as revealed by ?-H2AX foci, chromosomal instability, aneuploidy with trisomy 15 and bystander effects on chromosomal aberration induction in co-cultured ROS-sensitive mutant cells, suggesting that the delayed generation of ROS is a primary cause of these phenomena. Abolishing the bystander effect of post-irradiation thymocytes by superoxide dismutase and catalase supports ROS involvement. Chromosomal instability in thymocytes resulted in the generation of abnormal cell clones bearing trisomy 15 and aberrant karyotypes in the thymus. The emergence of thymic lymphomas from the thymocyte population containing abnormal cell clones indicated that clones with trisomy 15 and altered karyotypes were prelymphoma cells with the potential to develop into thymic lymphomas. The oncogene Notch1 was rearranged after the prelymphoma cells were established. Thus, delayed nontargeted <span class="hlt">radiation</span> effects drive thymic lymphomagenesis through the induction of characteristic changes in intrathymic immature T cells and the generation of prelymphoma cells. PMID:23297316</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=SCIGOV-STC&redirectUrl=http://www.osti.gov/scitech/biblio/6407937"><span id="translatedtitle">Altered gastric emptying and prevention of <span class="hlt">radiation-induced</span> vomiting in dogs. [Cobalt 60 irradiation</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Dubois, A.; Jacobus, J.P.; Grissom, M.P.; Eng, R.R.; Conklin, J.J.</p> <p>1984-03-01</p> <p>The relation between <span class="hlt">radiation-induced</span> vomiting and gastric emptying is unclear and the treatment of this condition is not established. We explored, therefore, (a) the effect of cobalt 60 irradiation on gastric emptying of solids and liquids and (b) the possibility of preventing <span class="hlt">radiation-induced</span> vomiting with the dopamine antagonist, domperidone. Twenty dogs were studied on two separate days, blindly and in random order, after i.v. injection of either a placebo or 0.06 mg/kg domperidone. On a third day, they received 8 Gy (800 rads) whole body irradiation with cobalt 60 gamma-rays after either placebo (n . 10) or domperidone (n . 10). Before each study, each dog was fed chicken liver tagged in vivo with 99mTc-sulfur colloid (solid marker), and water containing 111In-diethylenetriamine pentaacetic acid (liquid marker). Dogs were placed in a Pavlov stand for the subsequent 3 h and radionuclide imaging was performed at 10-min intervals. Irradiation produced vomiting in 9 of 10 dogs given placebo but only in 1 of 10 dogs pretreated with domperidone (p less than 0.01). Gastric emptying of liquids and solids was significantly suppressed by irradiation (p less than 0.01) after both placebo and domperidone. These results demonstrate that <span class="hlt">radiation-induced</span> vomiting is accompanied by suppression of gastric emptying. Furthermore, domperidone prevents vomiting produced by ionizing <span class="hlt">radiation</span> but does not alter the accompanying delay of gastric emptying.</p> </li> <li> <p><a target="resultTitleLink" href="http://www.science.gov/scigov/desktop/en/ostiblue/service/link/track?type=RESULT&searchId=topic-pages&collectionCode=NASA-TRS&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20040088539&hterms=DNA&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DDNA"><span id="translatedtitle">Clustered DNA damages <span class="hlt">induced</span> by high and low LET <span class="hlt">radiation</span>, including heavy ions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sutherland, B. M.; Bennett, P. V.; Schenk, H.; Sidorkina, O.; Laval, J.; Trunk, J.; Monteleone, D.; Sutherland, J.; Lowenstein, D. I. (Principal Investigator)</p> <p>2001-01-01</p> <p>Clustered DNA damages--here defined as two or more lesions (strand breaks, oxidized purines, oxidized pyrimidines or abasic sites) within a few helical turns--have been postulated as difficult to repair accurately, and thus highly significant biological lesions. Further, attempted repair of clusters may produce double strand breaks (DSBs). However, until recently, there was no way to measure ionizing <span class="hlt">radiation-induced</span> clustered damages, except DSB. We recently described an approach for measuring classes of clustered damages (oxidized purine clusters, oxidized pyrimidine clusters, abasic clusters, along with DSB). We showed that ionizing <span class="hlt">radiation</span> (gamma rays and Fe ions, 1 GeV/amu) does <span class="hlt">induce</span> such clusters in genomic DNA in solution and in human cells. These studies also showed that each damage cluster results from one <span class="hlt">radiation</span> hit (and its track), thus indicating that they can be <span class="hlt">induced</span> by very low doses of <span class="hlt">radiation</span>, i.e. two independent hits are not required for cluster induction. Further, among all complex damages, double strand breaks comprise--at most-- 20%, with the other clustered damages being at least 80%.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li class="active"><span>25</span></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_25 --> <center> <div class="footer-extlink text-muted"><small>Some links on this page may take you to non-federal websites. 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