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Sample records for radiation induced reactions

  1. Prophylaxis and management of acute radiation-induced skin reactions: a systematic review of the literature

    PubMed Central

    Salvo, N.; Barnes, E.; van Draanen, J.; Stacey, E.; Mitera, G.; Breen, D.; Giotis, A.; Czarnota, G.; Pang, J.; De Angelis, C.

    2010-01-01

    Radiation therapy is a common treatment for cancer patients. One of the most common side effects of radiation is acute skin reaction (radiation dermatitis) that ranges from a mild rash to severe ulceration. Approximately 85% of patients treated with radiation therapy will experience a moderate-to-severe skin reaction. Acute radiation-induced 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 radiation-induced skin reactions. We conducted a literature review to identify trials that investigated products for the prophylaxis and management of acute radiation 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 Radiation 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 radiation-induced 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 radiation-induced 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 radiation-induced skin reactions. Future trials should focus

  2. Prophylaxis and management of acute radiation-induced skin reactions: a systematic review of the literature.

    PubMed

    Salvo, N; Barnes, E; van Draanen, J; Stacey, E; Mitera, G; Breen, D; Giotis, A; Czarnota, G; Pang, J; De Angelis, C

    2010-08-01

    Radiation therapy is a common treatment for cancer patients. One of the most common side effects of radiation is acute skin reaction (radiation dermatitis) that ranges from a mild rash to severe ulceration. Approximately 85% of patients treated with radiation therapy will experience a moderate-to-severe skin reaction. Acute radiation-induced 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 radiation-induced skin reactions. We conducted a literature review to identify trials that investigated products for the prophylaxis and management of acute radiation 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 Radiation 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 radiation-induced 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 radiation-induced 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 radiation-induced skin reactions. Future trials should focus on

  3. Delayed gamma radiation from lightning induced nuclear reactions

    NASA Astrophysics Data System (ADS)

    Greenfield, M. B.; Sakuma, K.; Ikeda, Y.; Kubo, K.

    2004-03-01

    An increase in atmospheric gamma radiation observed with NaI and Ge detectors positioned about 15 m above ground was observed following natural lightning near Tokyo, Japan [1]. Background subtracted gamma ray rates GRR following numerous lightning strokes observed since 2001 persisted for a few hours and subsequently decayed with a half-life of about 50 minutes. Using a 3x3 Ge detector, with 2 KeV resolution, positioned about 2 m from one of the NaI detectors increases in GRR were observed minutes after the onset of lightning with a delayed 50 min exponential decay. Although most of the increase in activity occured at less than a few 100 KeV, on July 11, 2003 a 1267 +/-2 KeV line was observed. Although the statistics of this event were poor, the appearance of this line with an exponential decay of 50 min half-life suggests the possibility that it may be due to 39Cl (1267 MeV; half-life = 55.5 min) via the 40Ar(gamma,p)39Cl, 40Ar(p,2p)39Cl and/or 40Ar(n,d)39Cl reactions. Observations of > 10 MeV gamma rays observed in NaI detectors within 10s of meters from and coincident with rocket-triggered lightning at the International Center for Lightning Research and Testing suggest that charged particles accelerated in intense electric fields associated with lightning give rise to photons with sufficient energy to initiate nuclear reactions [2]. Further work to explain the cause of this anomalous activity is underway using natural and triggered lightning. 1. M. B. Greenfield et al., Journal of Applied Physics 93 no. 3 (2003) pp 1839-184. 2. J. R. Dwyer et al., Science 299, (2003), pp 694-697 and recent communications

  4. Radiation-induced reactions of COH 2 gas mixtures over various solid catalysts

    NASA Astrophysics Data System (ADS)

    Nagai, S.; Arai, H.; Hatada, M.

    Studies have been carried out of radiation-induced reactions of COH 2 gas mixtures in the presence of various solid catalysts in order to find possibilities of synthesizing organic raw materials from COH 2 by radiation for the future. The solid catalysts studied include Fischer-Tropsch catalyst (FeCu supported by diatomaceous earth), titania(TiO 2), and silica gel. Analysis of the reaction products over Fischer-Tropsch catalyst or semiconductors such as TiO 2 and ZnOCr 2O 3 reveals that these solid catalysts do not sensitize the radiation chemical reaction of COH 2 but show the secondary effects on the reaction so as to induce the hydrogenation of olefins produced by the catalytic reaction and of aldehydes produced in gas phase by radiation. On the other hand, silica gel and other insulators such as alumina have been found to exhibit high catalytic activity in the formation of hydrocarbons from COH 2 under electron beam irradiation at 300°C. It has been shown experimentally that secondary reactions between H 2 and carbonaceous solid produced from CO make a substantial contribution to the formation of hydrocarbons from COH 2 over silica gel. In an attempt to find the role of silica gel in the reaction to produce hydrocarbons, radiation-induced reactions have been studied of H 2 with the carbonaceous solid that had been produced by irradiation of CO in the absence of solid catalyst, over TiO 2, or over silica gel. The results indicate that silica gel not only enhances the yields of CO 2 and carbonaceous solid from CO but also promotes hydrogenation reactions of the carbonaceous solid under electron beam irradiation.

  5. Functional properties of nisin-carbohydrate conjugates formed by radiation induced Maillard reaction

    NASA Astrophysics Data System (ADS)

    Muppalla, Shobita R.; Sonavale, Rahul; Chawla, Surinder P.; Sharma, Arun

    2012-12-01

    Nisin-carbohydrate conjugates were prepared by irradiating nisin either with glucose or dextran. Increase in browning and formation of intermediate products was observed with a concomitant decrease in free amino and reducing sugar groups indicating occurrence of the Maillard reaction catalyzed by irradiation. Nisin-carbohydrate conjugates showed a broad spectrum antibacterial activity against Gram negative bacteria (Escherichia coli, Pseudomonas fluorescence) as well as Gram positive bacteria (Staphylococcus aureus, Bacillus cereus). Results of antioxidant assays, including that of DPPH radical-scavenging activity and reducing power, showed that the nisin-dextran conjugates possessed better antioxidant potential than nisin-glucose conjugate. These results suggested that it was possible to enhance the functional properties of nisin by preparing radiation induced conjugates suitable for application in food industry.

  6. Acemannan-containing wound dressing gel reduces radiation-induced skin reactions in C3H mice

    SciTech Connect

    Roberts, D.B.; Travis, E.L.

    1995-07-15

    To determine (a) whether a wound dressing gel that contains acemannan extracted from aloe leaves affects the severity of radiation-induced acute skin reactions in C3H mice; (b) if so, whether other commercially available gels such as a personal lubricating jelly and a healing ointment have similar effects; and (c) when the wound dressing gel should be applied for maximum effect. Male C3H mice received graded single doses of gamma radiation ranging from 30 to 47.5 Gy to the right leg. In most experiments, the gel was applied daily beginning immediately after irradiation. Dose-response curves were obtained by plotting the percentage of mice that reached or exceeded a given peak skin reaction as a function of dose. Curves were fitted by logit analysis and ED{sub 50} values, and 95% confidence limits were obtained. The average peak skin reactions of the wound dressing gel-treated mice were lower than those of the untreated mice at all radiation doses tested. The ED{sub 50} values for skin reactions of 2.0-2.75 were approximately 7 Gy higher in the wound dressing gel-treated mice. The average peak skin reactions and the ED{sub 50} values for mice treated with personal lubricating jelly or healing ointment were similar to irradiated control values. Reduction in the percentage of mice with skin reactions of 2.5 or more was greatest in the groups that received wound dressing gel for at least 2 weeks beginning immediately after irradiation. There was no effect if gel was applied only before irradiation or beginning 1 week after irradiation. Wound dressing gel, but not personal lubricating jelly or healing ointment, reduces acute radiation-induced skin reactions in C3H mice if applied daily for at least 2 weeks beginning immediately after irradiation. 31 refs., 4 figs., 1 tab.

  7. Radiation reaction induced non-monotonic features in runaway electron distributions

    NASA Astrophysics Data System (ADS)

    Hirvijoki, E.; Pusztai, I.; Decker, J.; Embréus, O.; Stahl, A.; Fülöp, T.

    2015-10-01

    > Runaway electrons, which are generated in a plasma where the induced electric field exceeds a certain critical value, can reach very high energies in the MeV range. For such energetic electrons, radiative losses will contribute significantly to the momentum space dynamics. Under certain conditions, due to radiative momentum losses, a non-monotonic feature - a `bump' - can form in the runaway electron tail, creating a potential for bump-on-tail-type instabilities to arise. Here, we study the conditions for the existence of the bump. We derive an analytical threshold condition for bump appearance and give an approximate expression for the minimum energy at which the bump can appear. Numerical calculations are performed to support the analytical derivations.

  8. A facility for studying radiative capture reactions induced with radioactive beams at ISAC

    NASA Astrophysics Data System (ADS)

    D'Auria, J. M.; Buchmann, L.; Hutcheon, D.; Lipnik, P.; Hunter, D.; Rogers, J.; Helmer, R.; Giesen, U.; Olin, A.; Bricault, P.; Bateman, N.

    The measurement of low energy fusion reactions of importance to nuclear astrophysics scenarios are a prime objective of the physics program of the new ISAC facility, located at TRIUMF in Vancouver, Canada. Intense radioactive beams of 19Ne, 14,15O, 20,21Na, 17,18F and other low Z species with energies in the range of 0.15 to 1.5 MeV/mass unit will be available to measure cross sections and resonance strengths of alpha and proton induced reactions. An important component of the experimental configuration will be a new Recoil Product Detection Facility (RPDF) consisting of a windowless gas target, surrounded by a gamma array, while the recoils are separated from the intense radioactive beam using a Electro-Magnetic Separator (EMS) employing Wien filters. The recoiling reaction products will then be detected using either a Si μ-strip array or a gas filled detector. Using these devices along with coincidence requirements and time-of-flight conditions a background reduction factor of the order of 10 +15 is the present goal.

  9. A facility for studying radiative capture reactions induced with radioactive beams at ISAC

    NASA Astrophysics Data System (ADS)

    Giesen, U.; Buchmann, L.; Hutcheon, D.; Helmer, R.; Olin, A.; Bricault, P.; Bateman, N.; D'Auria, J. M.; Lipnik, P.; Hunter, D.; Rodgers, J.

    1996-04-01

    The measurement of low energy fusion reactions of importance to nuclear astrophysics scenarios are a prime objective of the physics program of the new ISAC facility, located at TRIUMF in Vancouver, Canada. Intense radioactive beams of e,19Ne, ,14,15O, a,20,21Na, 17,18F and other low Z species with energies in the range of 0.15 to 1.5 MeV/mass unit will be available to measure cross sections and resonance strengths of alpha and proton induced reactions, An important component of the experimental configuration will be a new Recoil Product Detection Facility (RPDF) consisting of a windowless gas target, surrounded by a gamma array, while the recoils are separated from the intense radioactive beam using a Electro-Magnetic Separator (EMS) employing Wien filters. The recoiling reaction products will then be detected using either a Si μ-strip array or a gas filled detector. Using these devices along with coincidence requirements and time-of-flight conditions a background reduction factor of the order of 10+15 is the present goal.

  10. Radiation induced redox reactions and fragmentation of constituent ions in ionic liquids II. Imidazolium cations.

    SciTech Connect

    Shkrob, I. A.; Marin, T. W.; Chemerisov, S. D.; Hatcher, J.; Wishart, J.

    2011-04-14

    In part 1 of this study, radiolytic degradation of constituent anions in ionic liquids (ILs) was examined. The present study continues the themes addressed in part 1 and examines the radiation chemistry of 1,3-dialkyl substituted imidazolium cations, which currently comprise the most practically important and versatile class of ionic liquid cations. For comparison, we also examined 1,3-dimethoxy- and 2-methyl-substituted imidazolium and 1-butyl-4-methylpyridinium cations. In addition to identification of radicals using electron paramagnetic resonance spectroscopy (EPR) and selective deuterium substitution, we analyzed stable radiolytic products using {sup 1}H and {sup 13}C nuclear magnetic resonance (NMR) and tandem electrospray ionization mass spectrometry (ESMS). Our EPR studies reveal rich chemistry initiated through 'ionization of the ions': oxidation and the formation of radical dications in the aliphatic arms of the parent cations (leading to deprotonation and the formation of alkyl radicals in these arms) and reduction of the parent cation, yielding 2-imidazolyl radicals. The subsequent reactions of these radicals depend on the nature of the IL. If the cation is 2-substituted, the resulting 2-imidazolyl radical is relatively stable. If there is no substitution at C(2), the radical then either is protonated or reacts with the parent cation forming a C(2)-C(2) {sigma}{sigma}*-bound dimer radical cation. In addition to these reactions, when methoxy or C{sub {alpha}}-substituted alkyl groups occupy the N(1,3) positions, their elimination is observed. The elimination of methyl groups from N(1,3) was not observed. Product analyses of imidazolium liquids irradiated in the very-high-dose regime (6.7 MGy) reveal several detrimental processes, including volatilization, acidification, and oligomerization. The latter yields a polymer with m/z of 650 {+-} 300 whose radiolytic yield increases with dose (0.23 monomer units per 100 eV for 1-methyl-3-butylimidazolium

  11. Influence of Double-Strand Break Repair on Radiation Therapy-Induced Acute Skin Reactions in Breast Cancer Patients

    SciTech Connect

    Mumbrekar, Kamalesh Dattaram; Fernandes, Donald Jerard; Goutham, Hassan Venkatesh; Sharan, Krishna; Vadhiraja, Bejadi Manjunath; Satyamoorthy, Kapaettu; Bola Sadashiva, Satish Rao

    2014-03-01

    Purpose: Curative radiation therapy (RT)-induced toxicity poses strong limitations for efficient RT and worsens the quality of life. The parameter that explains when and to what extent normal tissue toxicity in RT evolves would be of clinical relevance because of its predictive value and may provide an opportunity for personalized treatment approach. Methods and Materials: DNA double-strand breaks and repair were analyzed by microscopic γ-H2AX foci analysis in peripheral lymphocytes from 38 healthy donors and 80 breast cancer patients before RT, a 2 Gy challenge dose of x-ray exposed in vitro. Results: The actual damage (AD) at 0.25, 3, and 6 hours and percentage residual damage (PRD) at 3 and 6 hours were used as parameters to measure cellular radiosensitivity and correlated with RT-induced acute skin reactions in patients stratified as non-overresponders (NOR) (Radiation Therapy Oncology Group [RTOG] grade <2) and overresponders (OR) (RTOG grade ≥2). The results indicated that the basal and induced (at 0.25 and 3 hours) γ-H2AX foci numbers were nonsignificant (P>.05) between healthy control donors and the NOR and OR groups, whereas it was significant between ORs and healthy donors at 6 hours (P<.001). There was a significantly higher PRD in OR versus NOR (P<.05), OR versus healthy donors (P<.001) and NOR versus healthy donors (P<.01), supported further by the trend analysis (r=.2392; P=.0326 at 6 hours). Conclusions: Our findings strongly suggest that the measurement of PRD by performing γ-H2AX foci analysis has the potential to be developed into a clinically useful predictive assay.

  12. Interactions of Changing Solar Ultraviolet Radiation and Climate with Light Induced Chemical Reactions in Aquatic Environments

    EPA Science Inventory

    Changes in the ozone layer over the past two decades have resulted in increases in solar ultraviolet radiation that reach the surface of North American aquatic environments. Concurrent changes in atmospheric CO2 are resulting in changes in stratification and precipitation that ar...

  13. Radiation-induced reactions of amino acids adsorbed on solid surfaces

    NASA Astrophysics Data System (ADS)

    López-Esquivel Kranksith, L.; Negrón-Mendoza, A.; Mosqueira, F. G.; Ramos-Bernal, Sergio

    2010-07-01

    The purpose of this work is to study the adsorption of compounds such as amino acids on clays and carbon nanotubes (CNTs) as a possible phase in the chemical evolution that may have occurred on the primitive Earth or in extraterrestrial environments. We further study the behavior of amino acids adsorbed on these solid surfaces at different conditions of pH and levels of irradiation, simulating a high-radiation field at early Earth conditions. The relevance of this work is to explain the possible contribution of solids (clays and CNTs) as promoters of polymerization and as shields for the adsorbed organic compounds against external sources of energy. To this end, tryptophan, aspartic acid, and glutamic acid were adsorbed on fixed amounts of solid surfaces and were irradiated by a 60Co source for different periods of time at fixed dose rates. After irradiation, the amino acids were extracted from the solid and analyzed with UV and IR spectroscopes and high-performance liquid chromatography. The most efficient surface for adsorption of amino acids was clay, followed by CNTs. Studies of the gamma irradiation of amino acids adsorbed on clay (in the solid phase) show a low yield of recovery of the amino acid.

  14. Radiative capture reactions in astrophysics

    SciTech Connect

    Brune, Carl R.; Davids, Barry

    2015-08-07

    Here, the radiative capture reactions of greatest importance in nuclear astrophysics are identified and placed in their stellar contexts. Recent experimental efforts to estimate their thermally averaged rates are surveyed.

  15. Early and late skin reactions to radiotherapy for breast cancer and their correlation with radiation-induced DNA damage in lymphocytes

    PubMed Central

    López, Escarlata; Guerrero, Rosario; Núñez, Maria Isabel; del Moral, Rosario; Villalobos, Mercedes; Martínez-Galán, Joaquina; Valenzuela, Maria Teresa; Muñoz-Gámez, José Antonio; Oliver, Francisco Javier; Martín-Oliva, David; de Almodóvar, José Mariano Ruiz

    2005-01-01

    Introduction Radiotherapy outcomes might be further improved by a greater understanding of the individual variations in normal tissue reactions that determine tolerance. Most published studies on radiation toxicity have been performed retrospectively. Our prospective study was launched in 1996 to measure the in vitro radiosensitivity of peripheral blood lymphocytes before treatment with radical radiotherapy in patients with breast cancer, and to assess the early and the late radiation skin side effects in the same group of patients. We prospectively recruited consecutive breast cancer patients receiving radiation therapy after breast surgery. To evaluate whether early and late side effects of radiotherapy can be predicted by the assay, a study was conducted of the association between the results of in vitro radiosensitivity tests and acute and late adverse radiation effects. Methods Intrinsic molecular radiosensitivity was measured by using an initial radiation-induced DNA damage assay on lymphocytes obtained from breast cancer patients before radiotherapy. Acute reactions were assessed in 108 of these patients on the last treatment day. Late morbidity was assessed after 7 years of follow-up in some of these patients. The Radiation Therapy Oncology Group (RTOG) morbidity score system was used for both assessments. Results Radiosensitivity values obtained using the in vitro test showed no relation with the acute or late adverse skin reactions observed. There was no evidence of a relation between acute and late normal tissue reactions assessed in the same patients. A positive relation was found between the treatment volume and both early and late side effects. Conclusion After radiation treatment, a number of cells containing major changes can have a long survival and disappear very slowly, becoming a chronic focus of immunological system stimulation. This stimulation can produce, in a stochastic manner, late radiation-related adverse effects of varying severity

  16. Radiation Induced Genomic Instability

    SciTech Connect

    Morgan, William F.

    2011-03-01

    themselves to prolonged study, many tend to eliminate or rearrange the target chromosome until it is too small for further rearrangement. The observed frequency of induced instability by low and high linear-energy-transfer radiations greatly exceeds that observed for nuclear gene mutations at similar doses; hence, mutation of a gene or gene family is unlikely to be the initiating mechanism. Once initiated however, there is evidence in the GM10115 model system that it can be perpetuated over time by dicentric chromosome formation followed by bridge breakage fusion cycles (Marder and Morgan 1993), as well as recombinational events involving interstitial telomere like repeat sequences (Day et al. 1998). There is also increasing evidence that inflammatory type reactions (Lorimore et al. 2001, Lorimore and Wright 2003), presumably involving reactive oxygen and nitrogen species as well as cytokines and chemokines might be involved in driving the ustable phenotype (Liaikis et al. 2007, Hei et al. 2008). To this end there is very convincing evidence for such reactions being involved in another non-targeted effect associated with ionizing radiation, the bystander effect (Hei et al. 2008). Clearly the link between induced instability and bystander effects suggests common processes and inflammatory type reactions will likely be the subject of future investigation.

  17. Mixed Convective Flow of an Elastico-Viscous Fluid Past a Vertical Plate in the Presence of Thermal Radiation and Chemical Reaction with an Induced Magnetic Field

    NASA Astrophysics Data System (ADS)

    Das, Utpal Jyoti

    2016-01-01

    The purpose of the study is to investigate the steady, two-dimensional, hydromagnetic, mixed convection heat and mass transfer of a conducting, optically thin, incompressible, elastico-viscous fluid (characterized by the Walters' B' model) past a permeable, stationary, vertical, infinite plate in the presence of thermal radiation and chemical reaction with account for an induced magnetic field. The governing equations of the flow are solved by the series method, and expressions for the velocity field, induced magnetic field, temperature field, and the skin friction are obtained.

  18. Radiation Reaction and Thomson Scattering

    SciTech Connect

    Koga, James

    2007-07-11

    In recent years high power high irradiance lasers of peta-watt order have been or are under construction. In addition, in the next 10 years lasers of unprecedented powers, exa-watt, could be built If lasers such as these are focused to very small spot sizes, extremely high laser irradiances will be achieved. When electrons interact with such a laser, they become highly relativistic over very short time and spatial scales. Usually the motion of an electron under the influence of electromagnetic fields is influenced to a small extent by radiation emission from acceleration. However, under such violent acceleration the amount of radiation emitted by electrons can become so large that significant damping of the electron motion by the emission of this radiation can occur. In this lecture note we will study this problem of radiation reaction by first showing how the equations of motion are obtained. Then, we will examine the problems with such equations and what approximations are made. We will specifically examine the effects of radiation reaction on the Thomson scattering of radiation from counter-streaming laser pulses and high energy electrons through the numerical integration of the equations of motion. We will briefly address the fundamental physics, which can be addressed by using such high irradiance lasers interacting with high energy electrons.

  19. Vacuum Ultraviolet and Ultraviolet Radiation-Induced Effect of Hydrogenated Silicon Nitride Etching: Surface Reaction Enhancement and Damage Generation

    NASA Astrophysics Data System (ADS)

    Fukasawa, Masanaga; Miyawaki, Yudai; Kondo, Yusuke; Takeda, Keigo; Kondo, Hiroki; Ishikawa, Kenji; Sekine, Makoto; Matsugai, Hiroyasu; Honda, Takayoshi; Minami, Masaki; Uesawa, Fumikatsu; Hori, Masaru; Tatsumi, Tetsuya

    2012-02-01

    Photon-enhanced etching of SiNx:H films caused by the interaction between vacuum ultraviolet (VUV)/ultraviolet (UV) radiation and radicals in the fluorocarbon plasma was investigated by a technique with a novel sample setup of the pallet for plasma evaluation. The simultaneous injection of UV radiation and radicals causes a dramatic etch rate enhancement of SiNx:H films. Only UV radiation causes the film shrinkage of SiNx:H films owing to hydrogen desorption from the film. Capacitance-voltage characteristics of SiNx:H/Si substrates were studied before and after UV radiation. The interface trap density increased monotonically upon irradiating the UV photons with a wavelength of 248 nm. The estimated effective interface trap generation probability is 4.74 ×10-7 eV-1·photon-1. Therefore, the monitoring of the VUV/UV spectra during plasma processing and the understanding of its impact on the surface reaction, film damage and electrical performance of underlying devices are indispensable to fabricate advanced devices.

  20. Laser induced nuclear reactions

    SciTech Connect

    Ledingham, Ken; McCanny, Tom; Graham, Paul; Fang Xiao; Singhal, Ravi; Magill, Joe; Creswell, Alan; Sanderson, David; Allott, Ric; Neely, David; Norreys, Peter; Santala, Marko; Zepf, Matthew; Watts, Ian; Clark, Eugene; Krushelnick, Karl; Tatarakis, Michael; Dangor, Bucker; Machecek, Antonin; Wark, Justin

    1998-12-16

    Dramatic improvements in laser technology since 1984 have revolutionised high power laser technology. Application of chirped-pulse amplification techniques has resulted in laser intensities in excess of 10{sup 19} W/cm{sup 2}. In the mid to late eighties, C. K. Rhodes and K. Boyer discussed the possibility of shining laser light of this intensity onto solid surfaces and to cause nuclear transitions. In particular, irradiation of a uranium target could induce electro- and photofission in the focal region of the laser. In this paper it is shown that {mu}Ci of {sup 62}Cu can be generated via the ({gamma},n) reaction by a laser with an intensity of about 10{sup 19} Wcm{sup -2}.

  1. Radiation recall reaction causing cardiotoxicity.

    PubMed

    Masri, Sofia Carolina; Misselt, Andrew James; Dudek, Arkadiusz; Konety, Suma H

    2014-01-01

    Radiation recall phenomenon is a tissue reaction that develops within a previously irradiated area, precipitated by the subsequent administration of certain chemotherapeutic agents. It commonly affects the skin, but can also involve internal organs with functional consequences. To our best knowledge, this phenomenon has never been reported as a complication on the heart and should be consider as a potential cause of cardiotoxicity. PMID:24755097

  2. Radiation-induced gliomas

    PubMed Central

    Prasad, Gautam; Haas-Kogan, Daphne A.

    2013-01-01

    Radiation-induced gliomas represent a relatively rare but well-characterized entity in the neuro-oncologic literature. Extensive retrospective cohort data in pediatric populations after therapeutic intracranial radiation show a clearly increased risk in glioma incidence that is both patient age- and radiation dose/volume-dependent. Data in adults are more limited but show heightened risk in certain groups exposed to radiation. In both populations, there is no evidence linking increased risk associated with routine exposure to diagnostic radiation. At the molecular level, recent studies have found distinct genetic differences between radiation-induced gliomas and their spontaneously-occurring counterparts. Clinically, there is understandable reluctance on the part of clinicians to re-treat patients due to concern for cumulative neurotoxicity. However, available data suggest that aggressive intervention can lead to improved outcomes in patients with radiation-induced gliomas. PMID:19831840

  3. Radiation reaction at ultrahigh intensities

    SciTech Connect

    Hammond, Richard T.

    2010-06-15

    Intensities of 10{sup 22} W cm{sup -2} have been reached and it is expected that this will be increased by two orders of magnitude in the near future. At these intensities the radiation reaction force is important, especially in calculating the terminal velocity of an electron. The following briefly describes some of the problems of the existing most well-known equations and describes an approach based on conservation of energy. The resulting equation is compared to the Landau Lifshitz and Ford O'Connell equations, and laboratory tests are proposed.

  4. Dressed Charge of Electron by Radiation Reaction

    NASA Astrophysics Data System (ADS)

    SETO, Keita; Zhang, Sen; KOGA, James; Moritaka, Toseo; Homma, Kensuke; Nakamiya, Yoshihide; NAGATOMO, Hideo; MIMA, Kunioki

    2016-03-01

    With the progress of ultraintense short pulse laser technologies, the maximum intensity of the lasers has reached the order of 1022W/cm2. Now, several institutes are aiming at higher intensities of over 1024∼W/cm2. It is expected that these lasers can investigate the regime of the ultra-intense field effects like electron-positron pair creation and annihilation, these high-intense laser fields enters into the non-linear QED regime. However, when an electron interacts with lasers with intensities over 1022W/cm2, it has been predicted that the radiation reaction effect becomes significant. The strong radiation field can induce the fluctuation of QED vacuum (vacuum polarization or photon-photon scatterings). Though the propagator for fields is deformed by it, some kind of a polarized charge exists as the dress. In this paper, we will discuss about this dress of an electron generated by radiation in the description of classical physics. It leads to the avoidance of the mathematical difficulty of the radiation reaction problems.

  5. Matrix-isolation studies on the radiation-induced chemistry in H₂O/CO₂ systems: reactions of oxygen atoms and formation of HOCO radical.

    PubMed

    Ryazantsev, Sergey V; Feldman, Vladimir I

    2015-03-19

    The radiation-induced transformations occurring upon X-ray irradiation of solid CO2/H2O/Ng systems (Ng = Ar, Kr, Xe) at 8-10 K and subsequent annealing up to 45 K were studied by Fourier transform infrared spectroscopy. The infrared (IR) spectra of deposited matrices revealed the presence of isolated monomers, dimers, and intermolecular H2O···CO2 complexes. Irradiation resulted in effective decomposition of matrix-isolated carbon dioxide and water yielding CO molecules and OH radicals, respectively. Annealing of the irradiated samples led to formation of O3, HO2, and a number of xenon hydrides of HXeY type (in the case of xenon matrices). The formation of these species was used for monitoring of the postirradiation thermally induced chemical reactions involving O and H atoms generated by radiolysis. It was shown that the radiolysis of CO2 in noble-gas matrices produced high yields of stabilized oxygen atoms. In all cases, the temperatures at which O atoms become mobile and react are lower than those of H atoms. Dynamics and reactivity of oxygen atoms was found to be independent of the precursor nature. In addition, the formation of HOCO radicals was observed in all the noble-gas matrices at remarkably low temperatures. The IR spectra of HOCO and DOCO were first characterized in krypton and xenon matrices. It was concluded that the formation of HOCO was mainly due to the radiation-induced evolution of the weakly bound H2O···CO2 complexes. This result indicates the significance of weak intermolecular interactions in the radiation-induced chemical processes in inert low-temperature media. PMID:25469518

  6. SU-E-J-273: Skin Temperature Recovery Rate as a Potential Predictor for Radiation-Induced Skin Reactions

    SciTech Connect

    Biswal, N C; Wu, Z; Chu, J; Sun, J

    2015-06-15

    Purpose: To assess the potential of dynamic infrared imaging to evaluate early skin reactions during radiation therapy in cancer patients. Methods: Thermal images were captured by our home-built system consisting of two flash lamps and an infrared (IR) camera. The surface temperature of the skin was first raised by ∼ 6 °C from ∼1 ms short flashes; the camera then captured a series of IR images for 10 seconds. For each image series, a basal temperature was recorded for 0.5 seconds before flash was triggered. The temperature gradients (ε) were calculated between a reference point (immediately after the flash) and at a time point of 2sec, 4sec and 9sec after that. A 1.0 cm region of interest (ROI) on the skin was drawn; the mean and standard deviations of the ROIs were calculated. The standard ε values for normal human skins were evaluated by imaging 3 healthy subjects with different skin colors. All of them were imaged on 3 separate days for consistency checks. Results: The temperature gradient, which is the temperature recovery rate, depends on the thermal properties of underlying tissue, i.e. thermal conductivity. The average ε for three volunteers averaged over 3 measurements were 0.64±0.1, 0.72±0.2 and 0.80±0.3 at 2sec, 4sec and 9sec respectively. The standard deviations were within 1.5%–3.2%. One of the volunteers had a prior small skin burn on the left wrist and the ε values for the burned site were around 9% (at 4sec) and 13% (at 9sec) lower than that from the nearby normal skin. Conclusion: The temperature gradients from the healthy subjects were reproducible within 1.5%–3.2 % and that from a burned skin showed a significant difference (9%–13%) from the normal skin. We have an IRB approved protocol to image head and neck patients scheduled for radiation therapy.

  7. Radiation reaction of multipole moments

    NASA Astrophysics Data System (ADS)

    Kazinski, P. O.

    2007-08-01

    A Poincaré-invariant description is proposed for the effective dynamics of a localized system of charged particles in classical electrodynamics in terms of the intrinsic multipole moments of the system. A relativistic-invariant definition for the intrinsic multipole moments of a system of charged particles is given. A new generally covariant action functional for a relativistic perfect fluid is proposed. In the case of relativistic charged dust, it is proven that the description of the problem of radiation reaction of multipole moments by the model of particles is equivalent to the description of this problem by a hydrodynamic model. An effective model is obtained for a pointlike neutral system of charged particles that possesses an intrinsic dipole moment, and the free dynamics of this system is described. The bound momentum of a point dipole is found.

  8. Radiation-induced osteochondromas

    SciTech Connect

    Libshitz, H.I.; Cohen, M.A.

    1982-03-01

    Radiation-induced osteochondromas, either single or multiple, occur more commonly than is generally recognized. The incidence following irradiation for childhood malignancy is approximately 12%. Any open epiphysis is vulnerable. Age at irradiation, time of appearance following therapy, dose and type of radiation, and clinical course in 14 cases are dicussed. Due to growth of the lesion and/or pain, 3 tumors were excised. None revealed malignant degeneration.

  9. The dependence of rate coefficients and product yields upon fluence, intensity, and time in unimolecular reactions induced by monochromatic infrared radiation

    NASA Astrophysics Data System (ADS)

    Quack, M.; Humbert, P.; van den Bergh, H.

    1980-07-01

    The influence of the three parameters (with two degrees of freedom) fluence, intensity, and time on rate coefficients and product yields in collisionless Unimolecular Reactions Induced by Monochromatic Infrared Radiation (URIMIR) is discussed in some detail in terms of the recently proposed logarithmic reactant fluence plots. Model calculations for several archetypes of such plots are presented, based on solutions of the Pauli master equation and solutions of the quantum mechanical equations of motion for spectra involving many states at each level of excitation. Linear diagrams, turnups, and turnovers are found and are discussed systematically. Experimental examples re-evaluated from the literature and new measurements on the laser induced decomposition of CF2HCl are reported which nicely illustrate the various theoretical possibilities. Steady state rate coefficients for six molecules are evaluated and summarized. In some situations the intrinsic nonlinear intensity dependence of the steady state rate coefficients and deviations from simple fluence dependence of the product yields both before and at steady state are shown to be important theoretically and experimentally. The role of the reducibility of the rate coefficient matrix is discussed in connection with turnovers and with the strong influence of initial temperature that is found in the laser induced decomposition of CF2HCl.

  10. 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.

  11. Acute and Chronic Cutaneous Reactions to Ionizing Radiation Therapy.

    PubMed

    Bray, Fleta N; Simmons, Brian J; Wolfson, Aaron H; Nouri, Keyvan

    2016-06-01

    Ionizing radiation is an important treatment modality for a variety of malignant conditions. However, development of radiation-induced skin changes is a significant adverse effect of radiation therapy (RT). Cutaneous repercussions of RT vary considerably in severity, course, and prognosis. When they do occur, cutaneous changes to RT are commonly graded as acute, consequential-late, or chronic. Acute reactions can have severe sequelae that impact quality of life as well as cancer treatment. Thus, dermatologists should be informed about these adverse reactions, know how to assess their severity and be able to determine course of management. The majority of measures currently available to prevent these acute reactions are proper skin hygiene and topical steroids, which limit the severity and decrease symptoms. Once acute cutaneous reactions develop, they are treated according to their severity. Treatments are similar to those used in prevention, but incorporate wound care management that maintains a moist environment to hasten recovery. Chronic changes are a unique subset of adverse reactions to RT that may develop months to years following treatment. Chronic radiation dermatitis is often permanent, progressive, and potentially irreversible with substantial impact on quality of life. Here, we also review the etiology, clinical manifestations, pathogenesis, prevention, and management of late-stage cutaneous reactions to radiotherapy, including chronic radiation dermatitis and radiation-induced fibrosis. PMID:27250839

  12. Quantum Radiation Reaction: From Interference to Incoherence

    NASA Astrophysics Data System (ADS)

    Dinu, Victor; Harvey, Chris; Ilderton, Anton; Marklund, Mattias; Torgrimsson, Greger

    2016-01-01

    We investigate quantum radiation reaction in laser-electron interactions across different energy and intensity regimes. Using a fully quantum approach which also accounts exactly for the effect of the strong laser pulse on the electron motion, we identify in particular a regime in which radiation reaction is dominated by quantum interference. We find signatures of quantum radiation reaction in the electron spectra which have no classical analogue and which cannot be captured by the incoherent approximations typically used in the high-intensity regime. These signatures are measurable with presently available laser and accelerator technology.

  13. Radiation-induced reactions of polymer radicals with ruthenium tris(bipyridyl)-OH adducts in aqueous solutions

    SciTech Connect

    Neta, P.; Silverman, J.; Markovic, V.; Rabani, J.

    1986-02-13

    Polymer radicals are produced by H abstraction from polyethylene glycol (PEG) and polybrene (PB) and by H abstraction and OH addition to polystyrenesulfonate (PSS). When ruthenium tris(bipyridyl) ions (Ru(bpy)/sub 3//sup 2 +/) are also present, they compete for OH and H radicals and produce the appropriate adducts. These adducts may disproportionate or react with the polymer radicals. The kinetic constants of these systems were measured by pulse radiolysis. The reaction products were also studied by dialysis of these systems following ..gamma..-irradiation. Under the conditions of these experiments the Ru(bpy)/sub 3//sup 2 +/-OH adduct (and probably also the corresponding H adduct) reacts with the polymer radicals. The products of these reactions are the appropriate polymer molecules with covalently bound Ru(bpy)/sub 3//sup 2 +/ residues. This method has a potential use in the synthesis of such compounds, which may be utilized for photochemical storage of light energy. 26 references, 4 figures, 1 table.

  14. Radiation-induced schwannomas

    SciTech Connect

    Rubinstein, A.B.; Reichenthal, E.; Borohov, H.

    1989-06-01

    The histopathology and clinical course of three patients with schwannomas of the brain and high cervical cord after therapeutic irradiation for intracranial malignancy and for ringworm of the scalp are described. Earlier reports in the literature indicated that radiation of the scalp may induce tumors in the head and neck. It is therefore suggested that therapeutic irradiation in these instances was a causative factor in the genesis of these tumors.

  15. Radiation-induced free radical reactions in polymer/drug systems for controlled release: an EPR investigation

    NASA Astrophysics Data System (ADS)

    Faucitano, A.; Buttafava, A.; Montanari, L.; Cilurzo, F.; Conti, B.; Genta, I.; Valvo, L.

    2003-05-01

    The primary and secondary free radical intermediates in the gamma radiolysis of poly(D,L-lactide-co-glycolide) (PLGA) and clonazepam loaded PLGA microspheres were investigated by matrix EPR spectroscopy in the temperature range 77-298 K. Drug-polymer interactions were found to be important leading to significant deviations of the G(radicals) from the additivity law. In particular, in the mixed system a stabilization of the polymer matrix with respect to the radiation damage was detected, witnessed by a decrease of the overall polymer radicals yield which is accompanied by an increase of the drug radicals yield. These effects have been attributed to the scavenging properties of the nitro group with respect to electrons and polymer radicals. It is conceivable that such conclusions be of general application for all pharmaceutical formulations containing drugs bearing nitro groups in their chemical structure.

  16. Detecting radiation reaction at moderate laser intensities.

    PubMed

    Heinzl, Thomas; Harvey, Chris; Ilderton, Anton; Marklund, Mattias; Bulanov, Stepan S; Rykovanov, Sergey; Schroeder, Carl B; Esarey, Eric; Leemans, Wim P

    2015-02-01

    We propose a new method of detecting radiation reaction effects in the motion of particles subjected to laser pulses of moderate intensity and long duration. The effect becomes sizable for particles that gain almost no energy through the interaction with the laser pulse. Hence, there are regions of parameter space in which radiation reaction is actually the dominant influence on charged particle motion. PMID:25768626

  17. [Radiation-induced neuropathy].

    PubMed

    Kolak, Agnieszka; Starosławska, Elzbieta; Kieszko, Dariusz; Cisek, Paweł; Patyra, Krzysztof Ireneusz; Surdyka, Dariusz; Dobrzyńska-Rutkowska, Aneta; Łopacka-Szatan, Karolina; Burdan, Franciszek

    2013-12-01

    Radiation-induced neuropathy is commonly observed among oncological patients. Radiation can affect the nervous tissue directly or indirectly by inducing vasculopathy or dysfunction of internal organs. Symptoms may be mild and reversible (e.g., pain, nausea, vomiting, fever, drowsiness, fatigue, paresthesia) or life-threatening (cerebral oedema, increased intracranial pressure, seizures). Such complications are clinically divided into peripheral (plexopathies, neuropathies of spinal and cranial nerves) and central neuropathy (myelopathy, encephalopathy, cognitive impairment). The degree of neuronal damages primarily depends on the total and fractional radiation dose and applied therapeutic methods. The conformal and megavoltage radiotherapy seems to be the safeties ones. Diagnostic protocol includes physical examination, imaging (in particular magnetic resonance), electromyography, nerve conduction study and sometimes histological examination. Prevention and early detection of neurological complications are necessary in order to prevent a permanent dysfunction of the nervous system. Presently their treatment is mostly symptomatic, but in same cases a surgical intervention is required. An experimental and clinical data indicates some effectiveness of different neuroprotective agents (e.g. anticoagulants, vitamin E, hyperbaric oxygen, pentoxifylline, bevacizumab, methylphenidate, donepezil), which should be administered before and/or during radiotherapy. PMID:24490474

  18. [Radiation-induced cancers].

    PubMed

    Dutrillaux, B

    1998-01-01

    The induction of malignant diseases is one of the most concerning late effects of ionising radiation. A large amount of information has been collected form atomic bomb survivors, patients after therapeutic irradiation, occupational follow-up and accidentally exposed populations. Major uncertainties persist in the (very) low dose range i.e., population and workers radioprotection. A review of the biological mechanisms leading to cancer strongly suggests that the vast majority of radiation-induced malignancies arise as a consequence of recessive mutations of tumour-suppressor genes. These mutations can be unveiled by ageing, this process being possibly furthered by constitutional or acquired genomic instability. The individual risk is likely to be very low, probably because of the usual dose level. However, the magnitude of medical exposure and the reliance of our societies on nuclear industry are so high that irreproachable decision-making processes and standards for practice are inescapable. PMID:9868399

  19. Prevention and treatment of acute radiation-induced skin reactions: a systematic review and meta-analysis of randomized controlled trials

    PubMed Central

    2014-01-01

    Background Radiation-induced skin reaction (RISR) is a common side effect that affects the majority of cancer patients receiving radiation treatment. RISR is often characterised by swelling, redness, pigmentation, fibrosis, and ulceration, pain, warmth, burning, and itching of the skin. The aim of this systematic review was to assess the effects of interventions which aim to prevent or manage RISR in people with cancer. Methods We searched the following databases up to November 2012: Cochrane Skin Group Specialised Register, CENTRAL (2012, Issue 11), MEDLINE (from 1946), EMBASE (from 1974), PsycINFO (from 1806), CINAHL (from 1981) and LILACS (from 1982). Randomized controlled trials evaluating interventions for preventing or managing RISR in cancer patients were included. The primary outcomes were development of RISR, and levels of RISR and symptom severity. Secondary outcomes were time taken to develop erythema or dry desquamation; quality of life; time taken to heal, a number of skin reaction and symptom severity measures; cost, participant satisfaction; ease of use and adverse effects. Where appropriate, we pooled results of randomized controlled trials using mean differences (MD) or odd ratios (OR) with 95% confidence intervals (CI). Results Forty-seven studies were included in this review. These evaluated six types of interventions (oral systemic medications; skin care practices; steroidal topical therapies; non-steroidal topical therapies; dressings and other). Findings from two meta-analyses demonstrated significant benefits of oral Wobe-Mugos E for preventing RISR (OR 0.13 (95% CI 0.05 to 0.38)) and limiting the maximal level of RISR (MD -0.92 (95% CI -1.36 to -0.48)). Another meta-analysis reported that wearing deodorant does not influence the development of RISR (OR 0.80 (95% CI 0.47 to 1.37)). Conclusions Despite the high number of trials in this area, there is limited good, comparative research that provides definitive results suggesting the

  20. Clindamycin-induced hypersensitivity reaction.

    PubMed

    Bulloch, Marilyn N; Baccas, Jonathan T; Arnold, Scott

    2016-06-01

    Drug-induced anaphylaxis is an unpredictable adverse reaction. Although it may occur with any medication, antibiotics induce more cases of anaphylaxis than any other medication class with most cases being induced by β-lactam antibiotics. Clindamycin is an antibiotic with good gram-positive and anaerobe coverage which is often used in patients with β-lactam allergies. We report the case of a 46-year-old female who experienced anaphylaxis after a dose of intravenous (IV) clindamycin. Following treatment with methylprednisolone, epinephrine, diphenhydramine, and albuterol, the patient stabilized. The patient's score on the Naranjo's algorithm was 8 (probable); a score of 9 (definite) limited only by absence of drug re-challenge. To our knowledge, this is the first report of a clindamycin-induced anaphylaxis where the patient was not exposed to any other agent that may have triggered the response, the first case in the United States, and only the third documented case in the literature. Clinicians should be aware of the potential for drug-induced anaphylaxis in all medications. PMID:26216470

  1. (Reaction mechanism studies of heavy ion induced nuclear reactions)

    SciTech Connect

    Mignerey, A.C.

    1991-01-01

    This report discusses the following research projects; decay of excited nuclei formed in La-induced reactions at E/A = 45 MeV; mass and charge distributions in Cl-induced heavy ion reactions; and mass and charge distributions in {sup 56}Fe + {sup 165}Ho at E/A = 12 MeV.

  2. Radiative reactions in halo effective field theory

    NASA Astrophysics Data System (ADS)

    Rupak, Gautam

    2016-03-01

    In this article we review the recent progress in radiative reaction calculations in halo effective field theory. We look at radiative capture and breakup processes that involve a halo nucleus with a single valence neutron or proton. Looking at 7Li(n,γ) 8Li,14C(n,γ)15C and related reactions, the dominant source of theoretical uncertainty in s- and p-wave halo nuclei reaction calculations is quantified in a model-independent framework. The analysis for neutron halos is extended to proton halo systems. The effective field theory results quantify which observable parameters of the strong interaction at low energy need to be determined more precisely for accurate cross-section calculations.

  3. Errors inducing radiation overdoses.

    PubMed

    Grammaticos, Philip C

    2013-01-01

    There is no doubt that equipments exposing radiation and used for therapeutic purposes should be often checked for possibly administering radiation overdoses to the patients. Technologists, radiation safety officers, radiologists, medical physicists, healthcare providers and administration should take proper care on this issue. "We must be beneficial and not harmful to the patients", according to the Hippocratic doctrine. Cases of radiation overdose are often reported. A series of cases of radiation overdoses have recently been reported. Doctors who were responsible, received heavy punishments. It is much better to prevent than to treat an error or a disease. A Personal Smart Card or Score Card has been suggested for every patient undergoing therapeutic and/or diagnostic procedures by the use of radiation. Taxonomy may also help. PMID:24251304

  4. Radiation-induced disease.

    PubMed

    Bobrow, M

    1993-01-01

    The term radiation covers a wide spectrum of forms of energy, most of which have at one stage or another been suspected of causing human ill health. In general, study of the effects of radiation on health involves a mix of scientific disciplines, from population epidemiology to physics, which are seldom if ever found in a single scientist. As a result, interdisciplinary communication is of the utmost importance, and is a potent source of misunderstanding and misinformation. The forms of radiation which have been most specifically associated with health effects include ionizing and ultraviolet radiation. Claimed effects of electromagnetic and microwave radiation (excluding thermal effects) are too indefinite for detailed consideration. Ionizing radiation is a well-documented mutagen, which clearly causes cancers in humans, and human exposure has been increased by atomic weapons testing and medical and industrial uses of radioactivity. There is also a growing awareness of the possible role of some types of natural radiation, such as radon, in causing disease. Ultraviolet radiation is also associated with cancers, and is suspected of involvement in the increasing incidence of skin cancers in European populations. Factors thought to underlie recent changes in exposure to these mutagens are discussed. PMID:8222990

  5. Estimation by radiation inactivation of the minimum functional size of acrosome-reaction-inducing substance (ARIS) in the starfish, Asterias amurensis.

    PubMed

    Ushiyama, A; Chiba, K; Shima, A; Hoshi, M

    1995-11-01

    In the starfish Asterias amurensis, the jelly coat of the eggs contains a glycoprotein essential for the induction of the acrosome reaction in homologous spermatozoa that is termed the acrosome-reaction-inducing substance (ARIS). ARIS is a highly sulphated and fucose-rich glycoprotein of extremely high molecular mass (> 10(4) kDa). ARIS was irradiated with high-energy electrons in order to estimate the minimum size required for its biological activity. The minimum functional unit or target size of ARIS was estimated to be c. 14 kDa by target size analysis. ARIS was significantly disintegrated by the irradiation, yet the total sugar content was not apparently reduced. The binding of 125I-labelled ARIS to spermatozoa competed with that of irradiated ARIS, although the affinity of ARIS was much reduced after irradiation. PMID:8730900

  6. Heat pump processes induced by laser radiation

    NASA Technical Reports Server (NTRS)

    Garbuny, M.; Henningsen, T.

    1980-01-01

    A carbon dioxide laser system was constructed for the demonstration of heat pump processes induced by laser radiation. The system consisted of a frequency doubling stage, a gas reaction cell with its vacuum and high purity gas supply system, and provisions to measure the temperature changes by pressure, or alternatively, by density changes. The theoretical considerations for the choice of designs and components are dicussed.

  7. Effective radii of deuteron-induced reactions

    SciTech Connect

    Hashimoto, Shintaro; Chiba, Satoshi; Yahiro, Masanobu; Ogata, Kazuyuki; Minomo, Kosho

    2011-05-15

    The continuum-discretized coupled-channels method (CDCC) for exclusive reactions and the eikonal reaction theory (ERT) as an extension of CDCC to inclusive reactions are applied to deuteron-induced reactions. The CDCC result reproduces experimental data on the reaction cross section for d+{sup 58}Ni scattering at 200 MeV/nucleon, and ERT provides data on the neutron-stripping cross section for inclusive {sup 7}Li(d,n) reaction at 40 MeV. For deuteron-induced reactions at 200 MeV/nucleon, target-dependence of the reaction, elastic-breakup, nucleon-stripping, nucleon-removal, and complete- and incomplete-fusion cross sections is clearly explained by simple formulas. Accuracy of the Glauber model is also investigated.

  8. 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.

  9. The role of MRI in the diagnosis of acute radiation reaction in breast cancer patient

    NASA Astrophysics Data System (ADS)

    Startseva, Zh A.; Musabaeva, L. I.; Usova, AV; Frolova, I. G.; Simonov, K. A.; Velikaya, V. V.

    2016-02-01

    A clinical case with acute radiation reaction of the left breast after organ-preserving surgery with 10 Gy IORT (24.8 Gy) conventional radiation therapy has been presented. Comprehensive MRI examination showed signs of radiation- induced damage to skin, soft tissues and vessels of the residual breast.

  10. Radiation reaction for a massless charged particle

    NASA Astrophysics Data System (ADS)

    Kazinski, P. O.; Sharapov, A. A.

    2003-07-01

    We derive effective equations of motion for a massless charged particle coupled to the dynamical electromagnetic field with regard to the radiation back reaction. It is shown that unlike the massive case, not all the divergences resulting from the self-action of the particle are Lagrangian, i.e., can be cancelled out by adding appropriate counterterms to the original action. Besides, the order of renormalized differential equations governing the effective dynamics turns out to be greater than the order of the corresponding Lorentz-Dirac equation for a massive particle. For the case of a homogeneous external field, the first radiative correction to the Lorentz equation is explicitly derived via the reduction of order procedure.

  11. Radiation-induced cardiovascular effects

    NASA Astrophysics Data System (ADS)

    Tapio, Soile

    Recent epidemiological studies indicate that exposure to ionising radiation enhances the risk of cardiovascular mortality and morbidity in a moderate but significant manner. Our goal is to identify molecular mechanisms involved in the pathogenesis of radiation-induced cardiovascular disease using cellular and mouse models. Two radiation targets are studied in detail: the vascular endothelium that plays a pivotal role in the regulation of cardiac function, and the myocardium, in particular damage to the cardiac mitochondria. Ionising radiation causes immediate and persistent alterations in several biological pathways in the endothelium in a dose- and dose-rate dependent manner. High acute and cumulative doses result in rapid, non-transient remodelling of the endothelial cytoskeleton, as well as increased lipid peroxidation and protein oxidation of the heart tissue, independent of whether exposure is local or total body. Proteomic and functional changes are observed in lipid metabolism, glycolysis, mitochondrial function (respiration, ROS production etc.), oxidative stress, cellular adhesion, and cellular structure. The transcriptional regulators Akt and PPAR alpha seem to play a central role in the radiation-response of the endothelium and myocardium, respectively. We have recently started co-operation with GSI in Darmstadt to study the effect of heavy ions on the endothelium. Our research will facilitate the identification of biomarkers associated with adverse cardiac effects of ionising radiation and may lead to the development of countermeasures against radiation-induced cardiac damage.

  12. [4-aminopyridine induced rage reaction in mice].

    PubMed

    Xu, J H; Liu, H C; Zhang, Y P

    1991-03-01

    Rage reaction was induced in mice by sc 4-aminopyridine (4-AP) 6 mg . kg-1. Mice appeared hyperreactive after 8-12 min and then squeaked and fought each other. These manifestations were most distinct in 10-30 min and subsided after 40-60 min. The occurrence of rage reaction on this dose level was around 90%. At higher doses 4-AP caused convulsions and death after evocation of rage reaction. The ED50 of 4-AP for eliciting rage reaction was 4.7 +/- 0.7 mg . kg-1 sc. No significant difference in induction of rage reaction was seen between male and female mice of different body weights. Both neuroleptic drugs (chlorpromazine, haloperidol, tarden and clozapine) and anxiolytic drugs (diazepam, chlordiazepoxide, and meprobamate) inhibited 4-AP-induced rage reaction in mice. Barbiturates, Chloral hydrate, methaqualone, morphine hydrochloride, aspirin, phenytoin sodium, diphenhydramine hydrochloride, atropine sulfate, and procaine hydrochloride did not affect rage reaction. The 4-AP-induced aggressive behavior, similar to that induced by electric footshock or isolation, has the merits of convenience to deal with and time saving. Hence we recommended it as a screening method for drugs with neuroleptic and anxiolytic activities. PMID:1685615

  13. Radiation and radiation reaction in continuous focusing channels

    SciTech Connect

    Huang, Zhirong; Chen, Pisin; Ruth, R.D.

    1994-12-31

    We show that the radiation damping rate of the transverse action of a particle in a straight, continuous focusing system is independent of the particle energy, and that no quantum excitation is induced. This absolute damping effect leads to the existence of a transverse ground state which the particle inevitably decays to, and yields the minimum beam emittance that one can ever attain, {gamma}{epsilon}{sub min} = {Dirac_h}/2mc, limited only by the uncertainty principle. Due to adiabatic invariance, the particle can be accelerated along the focusing channel in its ground state without any radiation energy loss. These findings may apply to bent systems provided that the focusing field dominates over the bending field.

  14. Dynamics of synchrotron VUV-induced intracluster reactions

    SciTech Connect

    Grover, J.R.

    1993-12-01

    Photoionization mass spectrometry (PIMS) using the tunable vacuum ultraviolet radiation available at the National Synchrotron Light Source is being exploited to study photoionization-induced reactions in small van der Waals mixed complexes. The information gained includes the observation and classification of reaction paths, the measurement of onsets, and the determination of relative yields of competing reactions. Additional information is obtained by comparison of the properties of different reacting systems. Special attention is given to finding unexpected features, and most of the reactions investigated to date display such features. However, understanding these reactions demands dynamical information, in addition to what is provided by PIMS. Therefore the program has been expanded to include the measurement of kinetic energy release distributions.

  15. Low-energy electron-induced reactions in condensed matter

    NASA Astrophysics Data System (ADS)

    Arumainayagam, Christopher R.; Lee, Hsiao-Lu; Nelson, Rachel B.; Haines, David R.; Gunawardane, Richard P.

    2010-01-01

    The goal of this review is to discuss post-irradiation analysis of low-energy (≤50 eV) electron-induced processes in nanoscale thin films. Because electron-induced surface reactions in monolayer adsorbates have been extensively reviewed, we will instead focus on low-energy electron-induced reactions in multilayer adsorbates. The latter studies, involving nanoscale thin films, serve to elucidate the pivotal role that the low-energy electron-induced reactions play in high-energy radiation-induced chemical reactions in condensed matter. Although electron-stimulated desorption (ESD) experiments conducted during irradiation have yielded vital information relevant to primary or initial electron-induced processes, we wish to demonstrate in this review that analyzing the products following low-energy electron irradiation can provide new insights into radiation chemistry. This review presents studies of electron-induced reactions in nanoscale films of molecular species such as oxygen, nitrogen trifluoride, water, alkanes, alcohols, aldehydes, ketones, carboxylic acids, nitriles, halocarbons, alkane and phenyl thiols, thiophenes, ferrocene, amino acids, nucleotides, and DNA using post-irradiation techniques such as temperature-programmed desorption (TPD), reflection-absorption infrared spectroscopy (RAIRS), X-ray photoelectron spectroscopy (XPS), high-resolution electron energy loss spectroscopy (HREELS), gel electrophoresis, and microarray fluorescence. Post-irradiation temperature-programmed desorption, in particular, has been shown to be useful in identifying labile radiolysis products as demonstrated by the first identification of methoxymethanol as a reaction product of methanol radiolysis. Results of post-irradiation studies have been used not only to identify radiolysis products, but also to determine the dynamics of electron-induced reactions. For example, studies of the radiolysis yield as a function of incident electron energy have shown that dissociative

  16. Radiation induced estane polymer crosslinking

    SciTech Connect

    Fletcher, M.; Foster, P.

    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.

  17. Quantum Radiation Reaction Effects in Multiphoton Compton Scattering

    SciTech Connect

    Di Piazza, A.; Hatsagortsyan, K. Z.; Keitel, C. H.

    2010-11-26

    Radiation reaction effects in the interaction of an electron and a strong laser field are investigated in the realm of quantum electrodynamics. We identify the quantum radiation reaction with the multiple photon recoils experienced by the laser-driven electron due to consecutive incoherent photon emissions. After determining a quantum radiation dominated regime, we demonstrate how in this regime quantum signatures of the radiation reaction strongly affect multiphoton Compton scattering spectra and that they could be measurable in principle with presently available laser technology.

  18. Permeability Changes in Reaction Induced Fracturing

    NASA Astrophysics Data System (ADS)

    Ulven, Ole Ivar; Malthe-Sørenssen, Anders; Kalia, Rajiv

    2013-04-01

    The process of fracture formation due to a volume increasing chemical reaction has been studied in a variety of different settings, e.g. weathering of dolerites by Røyne et al.[4], serpentinization and carbonation of peridotite by Rudge et al.[3] and replacement reactions in silica-poor igneous rocks by Jamtveit et al.[1]. It is generally assumed that fracture formation will increase the net permeability of the rock, and thus increase the reactant transport rate and subsequently the total reaction rate, as summarised by Kelemen et al.[2]. Røyne et al.[4] have shown that transport in fractures will have an effect on the fracture pattern formed. Understanding the feedback process between fracture formation and permeability changes is essential in assessing industrial scale CO2 sequestration in ultramafic rock, but little is seemingly known about how large the permeability change will be in reaction-induced fracturing under compression, and it remains an open question how sensitive a fracture pattern is to permeability changes. In this work, we study the permeability of fractures formed under compression, and we use a 2D discrete element model to study the fracture patterns and total reaction rates achieved with different permeabilities. We achieve an improved understanding of the feedback processes in reaction-driven fracturing, thus improving our ability to decide whether industrial scale CO2 sequestration in ultramafic rock is a viable option for long-term handling of CO2. References [1] Jamtveit, B, Putnis, C. V., and Malthe-Sørenssen, A., "Reaction induced fracturing during replacement processes," Contrib. Mineral Petrol. 157, 2009, pp. 127 - 133. [2] Kelemen, P., Matter, J., Streit, E. E., Rudge, J. F., Curry, W. B., and Blusztajn, J., "Rates and Mechanisms of Mineral Carbonation in Peridotite: Natural Processes and Recipes for Enhanced, in situ CO2 Capture and Storage," Annu. Rev. Earth Planet. Sci. 2011. 39:545-76. [3] Rudge, J. F., Kelemen, P. B., and

  19. Nuclear reactions induced by a pyroelectric accelerator.

    PubMed

    Geuther, Jeffrey; Danon, Yaron; Saglime, Frank

    2006-02-10

    This work demonstrates the use of pyroelectric crystals to induce nuclear reactions. A system based on a pair of pyroelectric crystals is used to ionize gas and accelerate the ions to energies of up to 200 keV. The system operates above room temperature by simply heating or cooling the pyroelectric crystals. A D-D fusion reaction was achieved with this technique, and 2.5 MeV neutrons were detected. The measured neutron yield is in good agreement with the calculated yield. This work also verifies the results published by Naranjo, Gimzewski, and Putterman [Nature (London) 434, 1115 (2005)]. PMID:16486940

  20. Reaction of runaway electron distributions to radiative processes

    NASA Astrophysics Data System (ADS)

    Stahl, Adam; Embréus, Ola; Hirvijoki, Eero; Pusztai, István; Decker, Joan; Newton, Sarah L.; Fülöp, Tünde

    2015-11-01

    The emission of electromagnetic radiation by a charged particle in accelerated motion is associated with a reduction in its energy, accounted for by the inclusion of a radiation reaction force in the kinetic equation. For runaway electrons in plasmas, the dominant radiative processes are the emission of bremsstrahlung and synchrotron radiation. In this contribution, we investigate the impact of the associated radiation reaction forces on the runaway electron distribution, using both analytical and numerical studies, and discuss the corresponding change to the runaway electron growth rate, which can be substantial. We also report on the formation of non-monotonic features in the runaway electron tail as a consequence of the more complicated momentum-space dynamics in the presence of radiation reaction.

  1. Photo-induced chemical reaction of trans-resveratrol.

    PubMed

    Zhao, Yue; Shi, Meng; Ye, Jian-Hui; Zheng, Xin-Qiang; Lu, Jian-Liang; Liang, Yue-Rong

    2015-03-15

    Photo-induced chemical reaction of trans-resveratrol has been studied. UV B, liquid state and sufficient exposure time are essential conditions to the photochemical change of trans-resveratrol. Three principal compounds, cis-resveratrol, 2,4,6-phenanthrenetriol and 2-(4-hydroxyphenyl)-5,6-benzofurandione, were successively generated in the reaction solution of trans-resveratrol (0.25 mM, 100% ethanol) under 100 μW cm(-2) UV B radiation for 4h. cis-Resveratrol, originated from isomerization of trans-resveratrol, resulted in 2,4,6-phenanthrenetriol through photocyclisation reaction meanwhile loss of 2 H. 2,4,6-Phenanthrenetriol played a role of photosensitizer producing singlet oxygen in the reaction pathway. The singlet oxygen triggered [4+2] cycloaddition reaction of trans-resveratrol, and then resulted in the generation of 2-(4-hydroxyphenyl)-5,6-benzofurandione through photorearrangement and oxidation reaction. The singlet oxygen reaction was closely related to the substrate concentration of trans-resveratrol in solution. PMID:25308653

  2. The influence of infrared radiation on short-term ultraviolet-radiation-induced injuries

    SciTech Connect

    Kaidbey, K.H.; Witkowski, T.A.; Kligman, A.M.

    1982-05-01

    Because heat has been reported to influence adversely short- and long-term ultraviolet (UV)-radiation-induced skin damage in animals, we investigated the short-term effects of infrared radiation on sunburn and on phototoxic reactions to topical methoxsalen and anthracene in human volunteers. Prior heating of the skin caused suppression of the phototoxic response to methoxsalen as evidenced by an increase in the threshold erythema dose. Heat administered either before or after exposure to UV radiation had no detectable influence on sunburn erythema or on phototoxic reactions provoked by anthracene.

  3. CW CO2 Laser Induced Chemical Reactions

    NASA Astrophysics Data System (ADS)

    Pola, Joseph

    1989-05-01

    CW CO2 laser driven reactions between sulfur hexafluoride and carbon oxide, carbon suboxide, carbonyl sulfide and carbon disulfide proceed at subatmospheric pressures and yield fluorinated carbon compounds and sulfur tetrafluoride. CW CO2 laser driven reactions of organic compounds in the presence of energy-conveying sulfur hexafluoride show reaction course different from that normally observed due to elimination of reactor hot surface effects. The examples concern the decomposition of polychlorohydrocarbons, 2-nitropropane, tert.-butylamine, allyl chloride, spirohexane, isobornyl acetate and the oxidation of haloolefins. CW CO2 laser induced fragmentation of 1-methyl-l-silacyclobutanes and 4-silaspiro(3.4)octane in the presence of sulfur hexafluoride is an effective way for preparation and deposition of stable organosilicon polymers.

  4. Helium-induced reactions in astrophysics

    SciTech Connect

    Hale, G.M.

    1997-11-01

    Helium-induced reactions play a crucial role in stellar nucleosynthesis. Carbon and oxygen are produced mainly during the helium-burning phase by the chain of reactions {sup 8}Be({alpha}, {gamma} + e{sup +}e{sup {minus}}){sup 12}C({alpha}, {gamma}){sup 16}O. The first step, often called triple-{alpha} capture, was proposed by Hoyle to bypass the mass stability gap at {sup 8}Be. The second step gives rise to the largest uncertainty in most of the calculated stellar abundances. Later {alpha}-captures on {sup 13}C are believed to be a major source of s-process neutrons. The status of each of these important reactions is reviewed here.

  5. Systemic immunotoxicity reactions induced by adjuvanted vaccines.

    PubMed

    Batista-Duharte, Alexander; Portuondo, Deivys; Pérez, O; Carlos, Iracilda Zeppone

    2014-05-01

    Vaccine safety is a topic of concern for the treated individual, the family, the health care personnel, and the others involved in vaccination programs as recipients or providers. Adjuvants are necessary components to warrant the efficacy of vaccines, however the overstimulation of the immune system is also associated with adverse effects. Local reactions are the most frequent manifestation of toxicity induced by adjuvanted vaccines and, with the exception of the acute phase response (APR), much less is known about the systemic reactions that follow vaccination. Their low frequency or subclinical expression meant that this matter has been neglected. In this review, various systemic reactions associated with immune stimulation will be addressed, including: APR, hypersensitivity, induction or worsening of autoimmune diseases, modification of hepatic metabolism and vascular leak syndrome (VLS), with an emphasis on the mechanism involved. Finally, the authors analyze the current focus of discussion about vaccine safety and opportunities to improve the design of new adjuvanted vaccines in the future. PMID:24607449

  6. Natural Oil-Based Emulsion Containing Allantoin Versus Aqueous Cream for Managing Radiation-Induced Skin Reactions in Patients With Cancer: A Phase 3, Double-Blind, Randomized, Controlled Trial

    SciTech Connect

    Chan, Raymond Javan; Mann, Jennifer; Tripcony, Lee; Keller, Jacqui; Cheuk, Robyn; Blades, Rae; Keogh, Samantha; Poole, Christopher; Walsh, Christopher

    2014-11-15

    Purpose: To investigate the effects of a natural oil-based emulsion containing allantoin versus aqueous cream for preventing and managing radiation-induced skin reactions. Methods and Materials: A total of 174 patients were randomized and participated in the study. Patients received either cream 1 (the natural oil-based emulsion containing allantoin) or cream 2 (aqueous cream). Skin toxicity, pain, itching, and skin-related quality of life scores were collected for up to 4 weeks after radiation treatment. Results: Patients who received cream 1 had a significantly lower average level of Common Terminology Criteria for Adverse Events at week 3 (P<.05) but had statistically higher average levels of skin toxicity at weeks 7, 8, and 9 (all P<.001). Similar results were observed when skin toxicity was analyzed by grades. With regards to pain, patients in the cream 2 group had a significantly higher average level of worst pain (P<.05) and itching (P=.046) compared with the cream 1 group at week 3; however, these differences were not observed at other weeks. In addition, there was a strong trend for cream 2 to reduce the incidence of grade 2 or more skin toxicity in comparison with cream 1 (P=.056). Overall, more participants in the cream 1 group were required to use another topical treatment at weeks 8 (P=.049) and 9 (P=.01). Conclusion: The natural oil-based emulsion containing allantoin seems to have similar effects for managing skin toxicity compared with aqueous cream up to week 5; however, it becomes significantly less effective at later weeks into the radiation treatment and beyond treatment completion (week 6 and beyond). There were no major differences in pain, itching, and skin-related quality of life. In light of these results, clinicians and patients can base their decision on costs and preferences. Overall, aqueous cream seems to be a more preferred option.

  7. Spin distribution in neutron induced preequilibrium reactions

    SciTech Connect

    Dashdorj, D; Kawano, T; Chadwick, M; Devlin, M; Fotiades, N; Nelson, R O; Mitchell, G E; Garrett, P E; Agvaanluvsan, U; Becker, J A; Bernstein, L A; Macri, R; Younes, W

    2005-10-04

    The preequilibrium reaction mechanism makes an important contribution to neutron-induced reactions above E{sub n} {approx} 10 MeV. The preequilibrium process has been studied exclusively via the characteristic high energy neutrons produced at bombarding energies greater than 10 MeV. They are expanding the study of the preequilibrium reaction mechanism through {gamma}-ray spectroscopy. Cross-section measurements were made of prompt {gamma}-ray production as a function of incident neutron energy (E{sub n} = 1 to 250 MeV) on a {sup 48}Ti sample. Energetic neutrons were delivered by the Los Alamos National Laboratory spallation neutron source located at the Los Alamos Neutron Science Center facility. The prompt-reaction {gamma} rays were detected with the large-scale Compton-suppressed Germanium Array for Neutron Induced Excitations (GEANIE). Neutron energies were determined by the time-of-flight technique. The {gamma}-ray excitation functions were converted to partial {gamma}-ray cross sections taking into account the dead-time correction, target thickness, detector efficiency and neutron flux (monitored with an in-line fission chamber). Residual state population was predicted using the GNASH reaction code, enhanced for preequilibrium. The preequilibrium reaction spin distribution was calculated using the quantum mechanical theory of Feshback, Kerman, and Koonin (FKK). The multistep direct part of the FKK theory was calculated for a one-step process. The FKK preequilibrium spin distribution was incorporated into the GNASH calculations and the {gamma}-ray production cross sections were calculated and compared with experimental data. The difference in the partial {gamma}-ray cross sections using spin distributions with and without preequilibrium effects is significant.

  8. Fluid transport in reaction induced fractures

    NASA Astrophysics Data System (ADS)

    Ulven, Ole Ivar; Sun, WaiChing; Malthe-Sørenssen, Anders

    2015-04-01

    The process of fracture formation due to a volume increasing chemical reaction has been studied in a variety of different settings, e.g. weathering of dolerites by Røyne et al. te{royne}, serpentinization and carbonation of peridotite by Rudge et al. te{rudge} and replacement reactions in silica-poor igneous rocks by Jamtveit et al. te{jamtveit}. It is generally assumed that fracture formation will increase the net permeability of the rock, and thus increase the reactant transport rate and subsequently the total rate of material conversion, as summarised by Kelemen et al. te{kelemen}. Ulven et al. te{ulven_1} have shown that for fluid-mediated processes the ratio between chemical reaction rate and fluid transport rate in bulk rock controls the fracture pattern formed, and Ulven et al. te{ulven_2} have shown that instantaneous fluid transport in fractures lead to a significant increase in the total rate of the volume expanding process. However, instantaneous fluid transport in fractures is clearly an overestimate, and achievable fluid transport rates in fractures have apparently not been studied in any detail. Fractures cutting through an entire domain might experience relatively fast advective reactant transport, whereas dead-end fractures will be limited to diffusion of reactants in the fluid, internal fluid mixing in the fracture or capillary flow into newly formed fractures. Understanding the feedback process between fracture formation and permeability changes is essential in assessing industrial scale CO2 sequestration in ultramafic rock, but little is seemingly known about how large the permeability change will be in reaction-induced fracturing. In this work, we study the feedback between fracture formation during volume expansion and fluid transport in different fracture settings. We combine a discrete element model (DEM) describing a volume expanding process and the related fracture formation with different models that describe the fluid transport in the

  9. DNA Double-Strand Break Analysis by {gamma}-H2AX Foci: A Useful Method for Determining the Overreactors to Radiation-Induced Acute Reactions Among Head-and-Neck Cancer Patients

    SciTech Connect

    Goutham, Hassan Venkatesh; Mumbrekar, Kamalesh Dattaram; Vadhiraja, Bejadi Manjunath; Fernandes, Donald Jerard; Sharan, Krishna; Kanive Parashiva, Guruprasad; Kapaettu, Satyamoorthy; Bola Sadashiva, Satish Rao

    2012-12-01

    Purpose: Interindividual variability in normal tissue toxicity during radiation therapy is a limiting factor for successful treatment. Predicting the risk of developing acute reactions before initiation of radiation therapy may have the benefit of opting for altered radiation therapy regimens to achieve minimal adverse effects with improved tumor cure. Methods and Materials: DNA double-strand break (DSB) induction and its repair kinetics in lymphocytes of head-and-neck cancer patients undergoing chemoradiation therapy was analyzed by counting {gamma}-H2AX foci, neutral comet assay, and a modified version of neutral filter elution assay. Acute normal tissue reactions were assessed by Radiation Therapy Oncology Group criteria. Results: The correlation between residual DSBs and the severity of acute reactions demonstrated that residual {gamma}-H2AX foci in head-and-neck cancer patients increased with the severity of oral mucositis and skin reaction. Conclusions: Our results suggest that {gamma}-H2AX analysis may have predictive implications for identifying the overreactors to mucositis and skin reactions among head-and-neck cancer patients prior to initiation of radiation therapy.

  10. Induced Smith-Purcell radiation

    NASA Astrophysics Data System (ADS)

    Klochkov, D. N.; Artemyev, A. I.; Oganesyan, K. B.; Rostovtsev, Y. V.; Hu, C.-K.

    2010-11-01

    Excitation of induced coherent Smith-Purcell (SP) radiation by relativistic magnetized electron beam in the absence of the resonator is considered within the framework of the dispersion equation. We have found that the dispersion equation for the SP instability is a quadratic equation for frequency. The first-step approximation for solution of the dispersion equation, giving the SP-spectrum of frequency, corresponds to the mirror boundary case, when the electron beam propagates above a plane metal surface (mirror). It was found that the conditions for both the Thompson and the Raman regimes of excitation do not depend on beam current and depend on the height of the beam above the grating surface. The growth rate of the instability in both cases is proportional to the square root of the electron beam current. No feedback is needed to provide the coherent emission.

  11. Classical radiation reaction in particle-in-cell simulations

    NASA Astrophysics Data System (ADS)

    Vranic, M.; Martins, J. L.; Fonseca, R. A.; Silva, L. O.

    2016-07-01

    Under the presence of ultra high intensity lasers or other intense electromagnetic fields the motion of particles in the ultrarelativistic regime can be severely affected by radiation reaction. The standard particle-in-cell (PIC) algorithms do not include radiation reaction effects. Even though this is a well known mechanism, there is not yet a definite algorithm nor a standard technique to include radiation reaction in PIC codes. We have compared several models for the calculation of the radiation reaction force, with the goal of implementing an algorithm for classical radiation reaction in the Osiris framework, a state-of-the-art PIC code. The results of the different models are compared with standard analytical results, and the relevance/advantages of each model are discussed. Numerical issues relevant to PIC codes such as resolution requirements, application of radiation reaction to macro particles and computational cost are also addressed. For parameters of interest where the classical description of the electron motion is applicable, all the models considered are shown to give comparable results. The Landau and Lifshitz reduced model is chosen for implementation as one of the candidates with the minimal overhead and no additional memory requirements.

  12. Alternate Alpha Induced Reactions for NIF Radiochemistry

    SciTech Connect

    Shaughnessy, D A; Moody, K J; Bernstein, L A

    2010-02-26

    Radiochemical analysis of NIF capsule residues has been identified as a potential diagnostic of NIF capsule performance. In particular, alpha-induced nuclear reactions that occur on tracer elements added to the NIF capsule have been shown through simulation to be a very sensitive diagnostic for mix. The short range of the alpha particles makes them representative of the hot spot where they are created through the fusion of deuterium and tritium. Reactions on elements doped into the innermost part of the capsule ablator would therefore be sensitive to material that had mixed into the hot spot. Radiochemical determinations of activated detector elements may perhaps be the only true measure of mix that occurs in a NIF capsule, particularly in cases when the capsule fails.

  13. Radiative corrections for (e,e{prime}p) reactions at GeV energies

    SciTech Connect

    R. Ent; B. W. Filippone; N. C. R. Makins; R. G. Milner; T. G. O'Neill; D. A. Wasson

    2000-05-01

    A general framework for applying radiative corrections to (e,e{prime}p) coincidence reactions at GeV energies is presented, with special emphasis to higher-order Bremsstrahlung effects, radiation from the scattered hadron, and the validity of peaking approximations. The sensitivity to the assumptions made in practically applying radiative corrections to (e,e{prime}p) data is extensively discussed. The general framework is tested against experimental data of the {sup 1}H(e,e{prime}p) reaction at momentum transfer values larger than 1.0 (GeV/c){sup 2}, where radiative processes become a dominant source of uncertainty. The formulas presented here can easily be modified for any other electron-induced coincidence reaction.

  14. Competing reaction channels in IR-laser-induced unimolecular reactions

    SciTech Connect

    Berman, M.R.

    1981-01-01

    The competing reaction channels in the unimolecular decomposition of two molecules, formaldehyde and tetralin were studied. A TEA CO/sub 2/ laser was used as the excitation source in all experiments. The dissociation of D/sub 2/CO was studied by infrared multiphoton dissociation (MPD) and the small-molecule nature of formaldehyde with regard to MPD was explored. The effect of collisions in MPD were probed by the pressure dependence of the MPD yield and ir fluorescence from multiphoton excited D/sub 2/CO. MPD yield shows a near cubic dependence in pure D/sub 2/CO which is reduced to a 1.7 power dependence when 15 torr of NO is added. The peak amplitude of 5 ..mu..m ir fluorescence from D/sub 2/CO is proportional to the square of the D/sub 2/CO pressure in pure D/sub 2/CO or in the presence of 50 torr of Ar. Results are explained in terms of bottlenecks to excitation at the v = 1 level which are overcome by a combination of vibrational energy transfer and rotational relaxation. The radical/molecule branching ratio in D/sub 2/CO MPD was 0.10 +- 0.02 at a fluence of 125 J/cm/sup 2/ at 946.0 cm/sup -1/. The barrier height to molecular dissociation was calculated to be 3.6 +- 2.0 kcal/mole below the radical threshold or 85.0 +- 3.0 kcal/mole above the ground state of D/sub 2/CO. In H/sub 2/CO, this corresponds to 2.5 +- 2.0 kcal/mole below the radical threshold or 83.8 +- 3.0 kcal/mole above the ground state. Comparison with uv data indicate that RRKM theory is an acceptable description of formaldehyde dissociation in the 5 to 10 torr pressure range. The unimolecular decomposition of tetralin was studied by MPD and SiF/sub 4/ - sensitized pyrolysis. Both techniques induce decomposition without the interference of catalytic surfaces. Ethylene loss is identified as the lowest energy reaction channel. Dehydrogenation is found to result from step-wise H atom loss. Isomerization via disproportionation is also identified as a primary reaction channel.

  15. A double-blind randomised controlled trial of a natural oil-based emulsion (Moogoo Udder Cream®) containing allantoin versus aqueous cream for managing radiation-induced skin reactions in patients with cancer

    PubMed Central

    2012-01-01

    Background Radiation-induced skin reaction (RISR) is one of the most common and distressing side effects of radiotherapy in patients with cancer. It is featured with swelling, redness, itching, pain, breaks in skin, discomfort, and a burning sensation. There is a lack of convincing evidence supporting any single practice in the prevention or management of RISR. Methods/Designs This double-blinded randomised controlled trial aims to investigate the effects of a natural oil-based emulsion containing allantoin (as known as Moogoo Udder Cream®) versus aqueous cream in reducing RISR, improving pain, itching and quality of life in this patient group. One group will receive Moogoo Udder Cream®. Another group will receive aqueous cream. Outcome measures will be collected using patient self-administered questionnaire, interviewer administered questionnaire and clinician assessment at commencement of radiotherapy, weekly during radiotherapy, and four weeks after the completion of radiotherapy. Discussion Despite advances of radiologic advances and supportive care, RISR are still not well managed. There is a lack of efficacious interventions in managing RISR. While anecdotal evidence suggests that Moogoo Udder Cream® may be effective in managing RISR, research is needed to substantiate this claim. This paper presents the design of a double blind randomised controlled trial that will evaluate the effects of Moogoo Udder Cream® versus aqueous cream for managing in RISR in patients with cancer. Trial registration ACTRN 12612000568819 PMID:22849762

  16. Medium-induced multi-photon radiation

    NASA Astrophysics Data System (ADS)

    Ma, Hao; Salgado, Carlos A.; Tywoniuk, Konrad

    2011-01-01

    We study the spectrum of multi-photon radiation off a fast quark in medium in the BDMPS/ASW approach. We reproduce the medium-induced one-photon radiation spectrum in dipole approximation, and go on to calculate the two-photon radiation in the Molière limit. We find that in this limit the LPM effect holds for medium-induced two-photon ladder emission.

  17. 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.

  18. Radiation reaction as a non-conservative force

    NASA Astrophysics Data System (ADS)

    Aashish, Sandeep; Haque, Asrarul

    2016-09-01

    We study a system of a finite size charged particle interacting with a radiation field by exploiting Hamilton’s principle for a non-conservative system recently introduced by Galley [1]. This formulation leads to the equation of motion of the charged particle that turns out to be the same as that obtained by Jackson [2]. We show that the radiation reaction stems from the non-conservative part of the effective action for a charged particle. We notice that a charge interacting with a radiation field modeled as a heat bath affords a way to justify that the radiation reaction is a non-conservative force. The topic is suitable for graduate courses on advanced electrodynamics and classical theory of fields.

  19. Radiation-induced genomic instability: radiation quality and dose response

    NASA Technical Reports Server (NTRS)

    Smith, Leslie E.; Nagar, Shruti; Kim, Grace J.; Morgan, William F.

    2003-01-01

    Genomic instability is a term used to describe a phenomenon that results in the accumulation of multiple changes required to convert a stable genome of a normal cell to an unstable genome characteristic of a tumor. There has been considerable recent debate concerning the importance of genomic instability in human cancer and its temporal occurrence in the carcinogenic process. Radiation is capable of inducing genomic instability in mammalian cells and instability is thought to be the driving force responsible for radiation carcinogenesis. Genomic instability is characterized by a large collection of diverse endpoints that include large-scale chromosomal rearrangements and aberrations, amplification of genetic material, aneuploidy, micronucleus formation, microsatellite instability, and gene mutation. The capacity of radiation to induce genomic instability depends to a large extent on radiation quality or linear energy transfer (LET) and dose. There appears to be a low dose threshold effect with low LET, beyond which no additional genomic instability is induced. Low doses of both high and low LET radiation are capable of inducing this phenomenon. This report reviews data concerning dose rate effects of high and low LET radiation and their capacity to induce genomic instability assayed by chromosomal aberrations, delayed lethal mutations, micronuclei and apoptosis.

  20. 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.

  1. Energy straggling and radiation reaction for magnetic bremsstrahlung.

    NASA Technical Reports Server (NTRS)

    Shen, C. S.; White, D.

    1972-01-01

    Using the method of quantum electrodynamics, the energy distribution of particles and emitted photons is calculated for the case when increases in the average energy of the photon emitted by synchrotron radiation to values appreciable compared to the energy of the particle give rise to particle energy straggling and radiation spectrum broadening. The classical radiative reaction effects which may be tested in this type of experiment are outlined, and a detailed quantum mechanical calculation is presented. The significance of energy straggling in astrophysics is discussed briefly.

  2. Radiation-induced sarcoma of the thyroid

    SciTech Connect

    Griem, K.L.; Robb, P.K.; Caldarelli, D.D.; Templeton, A.C. )

    1989-08-01

    A 23-year-old white man presented with a thyroid mass 12 years after receiving high-dose radiotherapy for a T2 and N1 lymphoepithelioma of the nasopharynx. Following subtotal thyroidectomy, a histopathologic examination revealed liposarcoma of the thyroid gland. The relationship between sarcomas and irradiation is described and Cahan and colleagues' criteria for radiation-induced sarcomas are reviewed. To our knowledge, we are presenting the first such case of a radiation-induced sarcoma of the thyroid gland.

  3. Radiation-induced neoplasms of the brain

    SciTech Connect

    Kumar, P.P.; Good, R.R.; Skultety, F.M.; Leibrock, L.G.; Severson, G.S.

    1987-04-01

    The histopathology of two patients with radiation-induced neoplasms of the brain following therapeutic irradiation for intracranial malignancies is described. The second neoplasms were an atypical meningioma and a polymorphous cell sarcoma, respectively. They occurred 12 and 23 years after irradiation (4000 rad), within the original field of irradiation. In both cases, the radiation-induced tumors were histologically distinct from the initial medulloblastomas. Both patients were retreated with local irradiation using permanent implantation of radioactive iodine-125 seeds.

  4. Radiation-induced lung injury

    SciTech Connect

    Rosiello, R.A.; Merrill, W.W. )

    1990-03-01

    The use of radiation therapy is limited by the occurrence of the potentially fatal clinical syndromes of radiation pneumonitis and fibrosis. Radiation pneumonitis usually becomes clinically apparent from 2 to 6 months after completion of radiation therapy. It is characterized by fever, cough, dyspnea, and alveolar infiltrates on chest roentgenogram and may be difficult to differentiate from infection or recurrent malignancy. The pathogenesis is uncertain, but appears to involve both direct lung tissue toxicity and an inflammatory response. The syndrome may resolve spontaneously or may progress to respiratory failure. Corticosteroids may be effective therapy if started early in the course of the disease. The time course for the development of radiation fibrosis is later than that for radiation pneumonitis. It is usually present by 1 year following irradiation, but may not become clinically apparent until 2 years after radiation therapy. It is characterized by the insidious onset of dyspnea on exertion. It most often is mild, but can progress to chronic respiratory failure. There is no known successful treatment for this condition. 51 references.

  5. Ion-Molecule Reactions in Gas Phase Radiation Chemistry.

    ERIC Educational Resources Information Center

    Willis, Clive

    1981-01-01

    Discusses some aspects of the radiation chemistry of gases, focusing on the ion-molecule and charge neutralization reactions which set study of the gas phase apart. Uses three examples that illustrate radiolysis, describing the radiolysis of (1) oxygen, (2) carbon dioxide, and (3) acetylene. (CS)

  6. Ultraviolet radiation induced discharge laser

    DOEpatents

    Gilson, Verle A.; Schriever, Richard L.; Shearer, James W.

    1978-01-01

    An ultraviolet radiation source associated with a suitable cathode-anode electrode structure, disposed in a gas-filled cavity of a high pressure pulsed laser, such as a transverse electric atmosphere (TEA) laser, to achieve free electron production in the gas by photoelectric interaction between ultraviolet radiation and the cathode prior to the gas-exciting cathode-to-anode electrical discharge, thereby providing volume ionization of the gas. The ultraviolet radiation is produced by a light source or by a spark discharge.

  7. Effects of radiation reaction in relativistic laser acceleration

    SciTech Connect

    Hadad, Y.; Labun, L.; Rafelski, J.; Elkina, N.; Klier, C.; Ruhl, H.

    2010-11-01

    The goal of this paper is twofold: to explore the response of classical charges to electromagnetic force at the level of unity in natural units and to establish a criterion that determines physical parameters for which the related radiation-reaction effects are detectable. In pursuit of this goal, the Landau-Lifshitz equation is solved analytically for an arbitrary (transverse) electromagnetic pulse. A comparative study of the radiation emission of an electron in a linearly polarized pulse for the Landau-Lifshitz equation and for the Lorentz force equation reveals the radiation-reaction-dominated regime, in which radiation-reaction effects overcome the influence of the external fields. The case of a relativistic electron that is slowed down by a counterpropagating electromagnetic wave is studied in detail. We further show that when the electron experiences acceleration of order unity, the dynamics of the Lorentz force equation, the Landau-Lifshitz equation and the Lorentz-Abraham-Dirac equation all result in different radiation emission that could be distinguished in experiment. Finally, our analytic and numerical results are compared with those appearing in the literature.

  8. Radiation-Reaction Trapping of Electrons in Extreme Laser Fields

    NASA Astrophysics Data System (ADS)

    Ji, L. L.; Pukhov, A.; Kostyukov, I. Yu.; Shen, B. F.; Akli, K.

    2014-04-01

    A radiation-reaction trapping (RRT) of electrons is revealed in the near-QED regime of laser-plasma interaction. Electrons quivering in laser pulse experience radiation reaction (RR) recoil force by radiating photons. When the laser field reaches the threshold, the RR force becomes significant enough to compensate for the expelling laser ponderomotive force. Then electrons are trapped inside the laser pulse instead of being scattered off transversely and form a dense plasma bunch. The mechanism is demonstrated both by full three-dimensional particle-in-cell simulations using the QED photonic approach and numerical test-particle modeling based on the classical Landau-Lifshitz formula of RR force. Furthermore, the proposed analysis shows that the threshold of laser field amplitude for RRT is approximately the cubic root of laser wavelength over classical electron radius. Because of the pinching effect of the trapped electron bunch, the required laser intensity for RRT can be further reduced.

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

    SciTech Connect

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

    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.

  10. Direct measurements of radiative capture reactions with DRAGON

    NASA Astrophysics Data System (ADS)

    Christian, Gregory

    2015-10-01

    Direct measurements of radiative proton and alpha capture reactions are crucial for understanding nucleosynthesis in a variety of astrophysical environments, including classical novae, supernovae, X-Ray bursts, and quiescent stellar burning. Often the most important reactions have very low cross sections or involve unstable targets, making laboratory measurements extremely challenging. The detector of recoils and gammas of nuclear reactions (DRAGON) at TRIUMF is a recoil mass separator designed to measure radiative capture reactions in inverse kinematics, with beam suppression factors as high as 1016. When combined with the intense radioactive beams available at the ISAC-I facility, DRAGON's capabilities are unique and world-leading. In this talk, I will give a brief technical overview of DRAGON before presenting results from recent experiments. Some highlights include the first-ever direct measurement of 38K(p , γ) 39Ca, a crucial reaction for determining the endpoint of nova nucleosynthesis, and measurements of 76Se(α , γ) 80Kr. The latter measurements determine the rate of the reverse reaction, 80Kr(γ , α) 76Se, an important waiting point in the synthesis of the p-nuclei. I will also discuss future (and ongoing) developments at DRAGON, including the commissioning of a new chamber for high-precision elastic scattering measurements and plans to determine the 330 keV resonance strength in 18F(p , γ) 19Ne via measurements of 15O(α , γ) 19Ne and 15O + α elastic scattering.

  11. Radiation-induced intracranial malignant gliomas

    SciTech Connect

    Shapiro, S.; Mealey, J. Jr.; Sartorius, C.

    1989-07-01

    The authors present seven cases of malignant gliomas that occurred after radiation therapy administered for diseases different from the subsequent glial tumor. Included among these seven are three patients who were treated with interstitial brachytherapy. Previously reported cases of radiation-induced glioma are reviewed and analyzed for common characteristics. Children receiving central nervous system irradiation appear particularly susceptible to induction of malignant gliomas by radiation. Interstitial brachytherapy may be used successfully instead of external beam radiotherapy in previously irradiated, tumor-free brain, and thus may reduce the risk of radiation necrosis. 31 references.

  12. Radiation-induced decomposition of explosives under extreme conditions

    SciTech Connect

    Giefers, Hubertus; Pravica, Michael; Yang, Wenge; Liermann, Peter

    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.

  13. [Quantification of radiation-induced genetic risk].

    PubMed

    Ehling, U H

    1987-05-01

    Associated with technical advances of our civilization is a radiation- and chemically-induced increase in the germ cell mutation rate in man. This would result in an increase in the frequency of genetic diseases and would be detrimental to future generations. It is the duty of our generation to keep this risk as low as possible. The estimation of the radiation-induced genetic risk of human populations is based on the extrapolation of results from animal experiments. Radiation-induced mutations are stochastic events. The probability of the event depends on the dose; the degree of the damage does not. The different methods to estimate the radiation-induced genetic risk will be discussed. The accuracy of the predicted results will be evaluated by a comparison with the observed incidence of dominant mutations in offspring born to radiation exposed survivors of the Hiroshima and Nagasaki atomic bombings. These methods will be used to predict the genetic damage from the fallout of the reactor accident at Chernobyl. For the exposure dose we used the upper limits of the mean effective life time equivalent dose from the fallout values in the Munich region. According to the direct method for the risk estimation we will expect for each 100 to 500 spontaneous dominant mutations one radiation-induced mutation in the first generation. With the indirect method we estimate a ratio of 100 dominant spontaneous mutations to one radiation-induced dominant mutation. The possibilities and the limitations of the different methods to estimate the genetic risk will be discussed. The discrepancy between the high safety standards for radiation protection and the low level of knowledge for the toxicological evaluation of chemical mutagens will be emphasized. PMID:3589954

  14. Radiation-induced squamous sialometaplasia

    SciTech Connect

    Leshin, B.; White, W.L.; Koufman, J.A. )

    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.

  15. Differences between Drug-Induced and Contrast Media-Induced Adverse Reactions Based on Spontaneously Reported Adverse Drug Reactions

    PubMed Central

    Suh, JinUk; Yang, MyungSuk; Kang, WonKu; Kim, EunYoung

    2015-01-01

    Objective We analyzed differences between spontaneously reported drug-induced (not including contrast media) and contrast media-induced adverse reactions. Methods Adverse drug reactions reported by an in-hospital pharmacovigilance center (St. Mary’s teaching hospital, Daejeon, Korea) from 2010–2012 were classified as drug-induced or contrast media-induced. Clinical patterns, frequency, causality, severity, Schumock and Thornton’s preventability, and type A/B reactions were recorded. The trends among causality tools measuring drug and contrast-induced adverse reactions were analyzed. Results Of 1,335 reports, 636 drug-induced and contrast media-induced adverse reactions were identified. The prevalence of spontaneously reported adverse drug reaction-related admissions revealed a suspected adverse drug reaction-reporting rate of 20.9/100,000 (inpatient, 0.021%) and 3.9/100,000 (outpatients, 0.004%). The most common adverse drug reaction-associated drug classes included nervous system agents and anti-infectives. Dermatological and gastrointestinal adverse drug reactions were most frequently and similarly reported between drug and contrast media-induced adverse reactions. Compared to contrast media-induced adverse reactions, drug-induced adverse reactions were milder, more likely to be preventable (9.8% vs. 1.1%, p < 0.001), and more likely to be type A reactions (73.5% vs. 18.8%, p < 0.001). Females were over-represented among drug-induced adverse reactions (68.1%, p < 0.001) but not among contrast media-induced adverse reactions (56.6%, p = 0.066). Causality patterns differed between the two adverse reaction classes. The World Health Organization–Uppsala Monitoring Centre causality evaluation and Naranjo algorithm results significantly differed from those of the Korean algorithm version II (p < 0.001). Conclusions We found differences in sex, preventability, severity, and type A/B reactions between spontaneously reported drug and contrast media-induced adverse

  16. 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.

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

    SciTech Connect

    Kobayashi, Hanako; Yazlovitskaya, Eugenia M.; Lin, P. Charles

    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. Induced radioactivity from industrial radiation processing

    NASA Astrophysics Data System (ADS)

    Lone, M. A.

    1990-12-01

    Analytic expressions are developed for quantitative analysis of radioactivity induced by radiation processing of products with electrons or photons. These expressions provide reasonable estimates of induced activity much faster than Monte Carlo simulations. Analysis of radioactivity from processing of meat with 10 MeV electrons shows an induced activity of less than 10 mBq/(kgkGy) just after irradiation. This is 4 orders of magnitude less than the natural background activity of about 100 Bq/kg found in meat. Five days after processing the induced activity will reduce by a factor of 300.

  19. Quantum radiation reaction in head-on laser-electron beam interaction

    NASA Astrophysics Data System (ADS)

    Vranic, Marija; Grismayer, Thomas; Fonseca, Ricardo A.; Silva, Luis O.

    2016-07-01

    In this paper, we investigate the evolution of the energy spread and the divergence of electron beams while they interact with different laser pulses at intensities where quantum effects and radiation reaction are of relevance. The interaction is modelled with a quantum electrodynamic (QED)-PIC code and the results are compared with those obtained using a standard PIC code with a classical radiation reaction module. In addition, an analytical model is presented that estimates the value of the final electron energy spread after the interaction with the laser has finished. While classical radiation reaction is a continuous process, in QED, radiation emission is stochastic. The two pictures reconcile in the limit when the emitted photons energy is small compared to the energy of the emitting electrons. The energy spread of the electron distribution function always tends to decrease with classical radiation reaction, whereas the stochastic QED emission can also enlarge it. These two tendencies compete in the QED-dominated regime. Our analysis, supported by the QED module, reveals an upper limit to the maximal attainable energy spread due to stochasticity that depends on laser intensity and the electron beam average energy. Beyond this limit, the energy spread decreases. These findings are verified for different laser pulse lengths ranging from short ∼30 fs pulses presently available to the long ∼150 fs pulses expected in the near-future laser facilities, and compared with a theoretical model. Our results also show that near future experiments will be able to probe this transition and to demonstrate the competition between enhanced QED induced energy spread and energy spectrum narrowing from classical radiation reaction.

  20. Imaging Radiation-Induced Normal Tissue Injury

    PubMed Central

    Robbins, Mike E.; Brunso-Bechtold, Judy K.; Peiffer, Ann M.; Tsien, Christina I.; Bailey, Janet E.; Marks, Lawrence B.

    2013-01-01

    Technological developments in radiation therapy and other cancer therapies have led to a progressive increase in five-year survival rates over the last few decades. Although acute effects have been largely minimized by both technical advances and medical interventions, late effects remain a concern. Indeed, the need to identify those individuals who will develop radiation-induced late effects, and to develop interventions to prevent or ameliorate these late effects is a critical area of radiobiology research. In the last two decades, preclinical studies have clearly established that late radiation injury can be prevented/ameliorated by pharmacological therapies aimed at modulating the cascade of events leading to the clinical expression of radiation-induced late effects. These insights have been accompanied by significant technological advances in imaging that are moving radiation oncology and normal tissue radiobiology from disciplines driven by anatomy and macrostructure to ones in which important quantitative functional, microstructural, and metabolic data can be noninvasively and serially determined. In the current article, we review use of positron emission tomography (PET), single photon emission tomography (SPECT), magnetic resonance (MR) imaging and MR spectroscopy to generate pathophysiological and functional data in the central nervous system, lung, and heart that offer the promise of, (1) identifying individuals who are at risk of developing radiation-induced late effects, and (2) monitoring the efficacy of interventions to prevent/ameliorate them. PMID:22348250

  1. Radiation induced conductivity in space dielectric materials

    SciTech Connect

    Hanna, R.; Paulmier, T. Belhaj, M.; Dirassen, B.; Molinie, P.; Payan, D.; Balcon, N.

    2014-01-21

    The radiation-induced conductivity of some polymers was described mainly in literature by a competition between ionization, trapping/detrapping, and recombination processes or by radiation assisted ageing mechanisms. Our aim is to revise the effect of the aforementioned mechanisms on the complex evolution of Teflon{sup ®} FEP under space representative ionizing radiation. Through the definition of a new experimental protocol, revealing the effect of radiation dose and relaxation time, we have been able to demonstrate that the trapping/recombination model devised in this study agrees correctly with the observed experimental phenomenology at qualitative level and allows describing very well the evolution of radiation induced conductivity with irradiation time (or received radiation dose). According to this model, the complex behavior observed on Teflon{sup ®} FEP may be basically ascribed to the competition between electron/hole pairs generation and recombination: electrons are deeply trapped and act as recombination centers for free holes. Relaxation effects have been characterized through successive irradiations steps and have been again well described with the defined model at qualitative level: recombination centers created by the irradiation induce long term alteration on the electric properties, especially the effective bulk conductivity. One-month relaxation does not allow a complete recovery of the material initial charging behavior.

  2. Radiation induced conductivity in space dielectric materials

    NASA Astrophysics Data System (ADS)

    Hanna, R.; Paulmier, T.; Molinie, P.; Belhaj, M.; Dirassen, B.; Payan, D.; Balcon, N.

    2014-01-01

    The radiation-induced conductivity of some polymers was described mainly in literature by a competition between ionization, trapping/detrapping, and recombination processes or by radiation assisted ageing mechanisms. Our aim is to revise the effect of the aforementioned mechanisms on the complex evolution of Teflon® FEP under space representative ionizing radiation. Through the definition of a new experimental protocol, revealing the effect of radiation dose and relaxation time, we have been able to demonstrate that the trapping/recombination model devised in this study agrees correctly with the observed experimental phenomenology at qualitative level and allows describing very well the evolution of radiation induced conductivity with irradiation time (or received radiation dose). According to this model, the complex behavior observed on Teflon® FEP may be basically ascribed to the competition between electron/hole pairs generation and recombination: electrons are deeply trapped and act as recombination centers for free holes. Relaxation effects have been characterized through successive irradiations steps and have been again well described with the defined model at qualitative level: recombination centers created by the irradiation induce long term alteration on the electric properties, especially the effective bulk conductivity. One-month relaxation does not allow a complete recovery of the material initial charging behavior.

  3. Management of radiation-induced urethral strictures

    PubMed Central

    Hofer, Matthias D.

    2015-01-01

    Radiation as a treatment option for prostate cancer has been chosen by many patients. One of the side effects encountered are radiation-induced urethral strictures which occur in up to 11% of patients. Radiation damage has often left the irradiated field fibrotic and with poor vascularization which make these strictures a challenging entity to treat. The mainstay of urologic management remains an urethroplasty procedure for which several approaches exist with variable optimal indication. Excision and primary anastomoses are ideal for shorter bulbar strictures that comprise the majority of radiation-induced urethral strictures. One advantage of this technique is that it does not require tissue transfers and success rates of 70-95% have consistently been reported. Substitution urethroplasty using remote graft tissue such as buccal mucosa are indicated if the length of the stricture precludes a tension-free primary anastomosis. Despite the challenge of graft survival in radiation-damaged and poorly vascularized recipient tissue, up to 83% of patients have been treated successfully although the numbers described in the literature are small. The most extensive repairs involve the use of tissue flaps, for example gracilis muscle, which may be required if the involved periurethral tissue is unable to provide sufficient vascular support for a post-operative urethral healing process. In summary, radiation-induced urethral strictures are a challenging entity. Most strictures are amenable to excision and primary anastomosis (EPA) with encouraging success rates but substitution urethroplasty may be indicated when extensive repair is needed. PMID:26816812

  4. 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.

  5. A report on radiation-induced gliomas

    SciTech Connect

    Salvati, M.; Artico, M.; Caruso, R.; Rocchi, G.; Orlando, E.R.; Nucci, F. )

    1991-01-15

    Radiation-induced gliomas are uncommon, with only 73 cases on record to date. The disease that most frequently occasioned radiation therapy has been acute lymphoblastic leukemia (ALL). Three more cases are added here, two after irradiation for ALL and one after irradiation for tinea capitis. In a review of the relevant literature, the authors stress the possibility that the ALL-glioma and the retinoblastoma-glioma links point to syndromes in their own right that may occur without radiation therapy.56 references.

  6. Radiation-induced hydrogen transfer in metals

    NASA Astrophysics Data System (ADS)

    Tyurin, Yu I.; Vlasov, V. A.; Dolgov, A. S.

    2015-11-01

    The paper presents processes of hydrogen (deuterium) diffusion and release from hydrogen-saturated condensed matters in atomic, molecular and ionized states under the influence of the electron beam and X-ray radiation in the pre-threshold region. The dependence is described between the hydrogen isotope release intensity and the current density and the electron beam energy affecting sample, hydrogen concentration in the material volume and time of radiation exposure to the sample. The energy distribution of the emitted positive ions of hydrogen isotopes is investigated herein. Mechanisms of radiation-induced hydrogen transfer in condensed matters are suggested.

  7. Investigation of GEV Proton-Induced Spallation Reactions

    NASA Astrophysics Data System (ADS)

    Hilscher, D.; Herbach, C.-M.; Jahnke, U.; Tishchenko, V. G.; Galin, J.; Lott, B.; Letourneau, A.; Peghaire, A.; Filges, D.; Goldenbaum, F.; Nünighoff, K.; Schaal, H.; Sterzenbach, G.; Wohlmuther, M.; Pienkowski, L.; Schröder, W. U.; Toke, J.

    2004-09-01

    A reliable modeling of GeV proton-induced spallation reactions is indispensable for the design of the spallation module and the target station of future accelerator driven hybrid reactors (ADS) or spallation neutron sources (ESS), in particular, to provide precise predictions for the neutron production, the radiation damage of materials (window), and the production of radioactivity (3H, 7Be etc.) in the target medium. Detailed experimental nuclear data are needed for sensitive validations and improvements of the models, whose predictive power is strongly dependent on the correct physical description of the three main stages of a spallation reaction: (i) the Intra-Nuclear-Cascade (INC) with the fast heating of the target nucleus, (ii) the de-excitation due to pre-equilibrium emission including the possibility of multi-fragmentation, and (iii) the statistical decay of thermally excited nuclei by evaporation of light particles and fission in the case of heavy nuclei. Key experimental data for this endeavor are absolute production cross sections and energy spectra for neutrons and light charged-particles (LCPs), emission of composite particles prior and post to the attainment of an equilibrated system, distribution of excitation energies deposited in the nuclei after the INC, and fission probabilities. Systematic measurements of such data are furthermore needed over large ranges of target nuclei and incident proton energies. Such data has been measured with the NESSI detector. An overview of new and previous results will be given.

  8. Radiation-induced Genomic Instability and Radiation Sensitivity

    SciTech Connect

    Varnum, Susan M.; Sowa, Marianne B.; Kim, Grace J.; Morgan, William F.

    2013-01-19

    The obvious relationships between reactive oxygen and nitrogen species, mitochondrial dysfunction, inflammatory type responses and reactive chemokines and cytokines suggests a general stress response induced by ionizing radiation most likely leads to the non-targeted effects described after radiation exposure. We argue that true bystander effects do not occur in the radiation therapy clinic. But there is no question that effects outside the target volume do occur. These “out of field effects” are considered very low dose effects in the context of therapy. So what are the implications of non-targeted effects on radiation sensitivity? The primary goal of therapy is to eradicate the tumor. Given the genetic diversity of the human population, lifestyle and environment factors it is likely some combination of these will influence patient outcome. Non-targeted effects may contribute to a greater or lesser extent. But consider the potential situation involving a partial body exposure due to a radiation accident or radiological terrorism. Non-targeted effects suggest that the tissue at risk for demonstrating possible detrimental effects of radiation exposure might be greater than the volume actually irradiated.

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

    SciTech Connect

    Lagadec, Chann; Vlashi, Erina; Alhiyari, Yazeed; Phillips, Tiffany M.; Bochkur Dratver, Milana; Pajonk, Frank

    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 γ-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 γ-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, γ-secretase inhibitors may prevent up-regulation of Notch receptor and ligand family members and thus reduce the number of surviving breast cancer stem cells.

  10. The reaction of [Ir(C 3,N'-bpy) (bpy) 2] 2+ with OH radicals and radiation induced covalent binding of the complex to several polymers in aqueous solutions

    NASA Astrophysics Data System (ADS)

    Behar, David; Neta, P.; Silverman, Joseph; Rabani, Joseph

    Irradiation of aqueous solutions of [Ir(C 3,N'-bpy) (bpy) 2] 2+ (IrP) produces a variety of OH adducts to IrP. The OH adducts decay by two second order processes separated in time. In the presence of both IrP and a soluble polymer, the OH radicals are shared between the IrP and the polymer, simultaneously producing OH adducts and polymer radicals. This is followed by radical-radical reactions. The rate constants of the various reactions between the OH adducts and the polymer radicals have been determined. The products of reactions of the OH adducts with polyethylene glycals (PEG .), polybrene radicals (PB .), and polystyrene sulfonate radicals (PSS .) are the respective polymers covalently linked to the iridium complex. This has been shown by dialysis as well as by spectral measurements. IrP behaves similarly to Ru (bpy) 2+3 which was studied before. This indicates that the radiation method may have a general use in the preparation of polymers with pendant bpy complexes.

  11. Nefazadone-induced acute dystonic reaction.

    PubMed

    Burda, A; Webster, K; Leikin, J B; Chan, S B; Stokes, K A

    1999-10-01

    A 53-y-o patient presented approximately 2 h after taking her first dose of nefazadone. Chief complaint was lip smacking with hand and arm gesturing. The patient also took 25 mg meclizine which she had used before with no adverse effects. Diphenhydramine followed by benztropine led to resolution of symptoms within 1 h. Patient subsequently used meclizine with no untoward reactions. Nefazadone should be added to the list of agents that cause acute dystonic reactions. PMID:10509438

  12. Neutron-induced reaction studies using stored ions

    NASA Astrophysics Data System (ADS)

    Glorius, Jan; Litvinov, Yuri A.; Reifarth, René

    2015-11-01

    Storage rings provide unique possibilities for investigations of nuclear reactions. Radioactive ions can be stored if the ring is connected to an appropriate facility and reaction studies are feasible at low beam intensities because of the recycling of beam particles. Using gas jet or droplet targets, charged particle-induced reactions on short-lived isotopes can be studied in inverse kinematics. In such a system a high-flux reactor could serve as a neutron target extending the experimental spectrum to neutron-induced reactions. Those could be studied over a wide energy range covering the research fields of nuclear astrophysics and reactor safety, transmutation of nuclear waste and fusion.

  13. Radiation-induced mutations and plant breeding

    SciTech Connect

    Naqvi, S.H.M.

    1985-01-01

    Ionizing radiation could cause genetic changes in an organism and could modify gene linkages. The induction of mutation through radiation is random and the probability of getting the desired genetic change is low but can be increased by manipulating different parameters such as dose rate, physical conditions under which the material has been irradiated, etc. Induced mutations have been used as a supplement to conventional plant breeding, particularly for creating genetic variability for specific characters such as improved plant structure, pest and disease resistance, and desired changes in maturity period; more than 200 varieties of crop plants have been developed by this technique. The Pakistan Atomic Energy Commission has used this technique fruitfully to evolve better germplasm in cotton, rice, chickpea, wheat and mungbean; some of the mutants have become popular commercial varieties. This paper describes some uses of radiation induced mutations and the results achieved in Pakistan so far.

  14. 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.

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

    SciTech Connect

    Starzewski, Jacek J.; Pajak, Jacek T.; Pawelczyk, Iwona; Lange, Dariusz; Golka, Dariusz . E-mail: dargolka@wp.pl; Brzeziska, Monika; Lorenc, Zbigniew

    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.

  16. Cataracts induced by microwave and ionizing radiation

    SciTech Connect

    Lipman, R.M.; Tripathi, B.J.; Tripathi, R.C.

    1988-11-01

    Microwaves most commonly cause anterior and/or posterior subcapsular lenticular opacities in experimental animals and, as shown in epidemiologic studies and case reports, in human subjects. The formation of cataracts seems to be related directly to the power of the microwave and the duration of exposure. The mechanism of cataractogenesis includes deformation of heat-labile enzymes, such as glutathione peroxide, that ordinarily protect lens cell proteins and membrane lipids from oxidative damage. Oxidation of protein sulfhydryl groups and the formation of high-molecular-weight aggregates cause local variations in the orderly structure of the lens cells. An alternative mechanism is thermoelastic expansion through which pressure waves in the aqueous humor cause direct physical damage to the lens cells. Cataracts induced by ionizing radiation (e.g., X-rays and gamma rays) usually are observed in the posterior region of the lens, often in the form of a posterior subcapsular cataract. Increasing the dose of ionizing radiation causes increasing opacification of the lens, which appears after a decreasing latency period. Like cataract formation by microwaves, cataractogenesis induced by ionizing radiation is associated with damage to the lens cell membrane. Another possible mechanism is damage to lens cell DNA, with decreases in the production of protective enzymes and in sulfur-sulfur bond formation, and with altered protein concentrations. Until further definitive conclusions about the mechanisms of microwaves and ionizing radiation induced cataracts are reached, and alternative protective measures are found, one can only recommend mechanical shielding from these radiations to minimize the possibility of development of radiation-induced cataracts. 74 references.

  17. Formation of Complex Molecules via radiative association reactions

    NASA Astrophysics Data System (ADS)

    Acharyya, Kinsuk; Herbst, Eric

    2016-07-01

    The detection of increasing numbers of complex organic molecules in the various phases of star formation plays a key role since they follow the same chemical rules of carbon-based chemistry that are observed in our planet Earth. Many of these molecules are believed to be formed on the surfaces of grains, and can then be released to the gas phase when these grains are heated. This is evident when we observe a rich chemistry in hot core regions. However, recently complex organic molecules have also been observed in cold clouds. Therefore, it is necessary to re-examine various pathways for the formation of these molecules in the gas phase. In this presentation, I will discuss role of radiative association reactions in the formation of complex molecules in the gas phase and at low temperature. We will compare abundance of assorted molecules with and without new radiative association reactions and will show that the abundance of a few complex molecules such as HCOOCH3, CH3OCH3 etc. can go up due to introduction of these reactions, which can help to explain their observed abundances.

  18. Bile acids in radiation-induced diarrhea

    SciTech Connect

    Arlow, F.L.; Dekovich, A.A.; Priest, R.J.; Beher, W.T.

    1987-10-01

    Radiation-induced bowel disease manifested by debilitating diarrhea is an unfortunate consequence of therapeutic irradiation for pelvic malignancies. Although the mechanism for this diarrhea is not well understood, many believe it is the result of damage to small bowel mucosa and subsequent bile acid malabsorption. Excess amounts of bile acids, especially the dihydroxy components, are known to induce water and electrolyte secretion and increase bowel motility. We have directly measured individual and total bile acids in the stool samples of 11 patients with radiation-induced diarrhea and have found bile acids elevated two to six times normal in eight of them. Our patients with diarrhea and increased bile acids in their stools had prompt improvement when given cholestyramine. They had fewer stools and returned to a more normal life-style.

  19. Ofloxacin Induced Cutaneous Reactions in Children

    PubMed Central

    Mishra, Sailen Kumar; Rath, Bandana; Rath, Saroj Sekhar

    2015-01-01

    Cutaneous adverse effects to antimicrobials are a major health problem. Though majority of them are mild and self-limiting, severe variants like Steven Johnson Syndrome (SJS), toxic epidermal necrolysis (TEN) are not uncommon. Ofloxacin, a fluoroquinolone widely used for the treatment of urinary tract infections, acute bacterial diarrheas, enteric fever, STDs and other soft tissue infections either as a single drug or in combination with other drugs. Earlier a case of mucocutaneous maculopapular rash with oral ofloxacin and was reported in an adult. In the present hospital set up there were few reports of such reactions to adults. Here we report three different variants of reactions associated with oral ofloxacin in chlidren. Early detection of cutaneous lesions and immediate withdrawal of the offending drug can prevent progression of such reactions to their severe variants as well as morbidity and mortality. PMID:26266136

  20. Cross sections of neutron-induced reactions

    SciTech Connect

    Mukhopadhyay, Tapan; Lahiri, Joydev; Basu, D. N.

    2010-10-15

    We study the properties of the neutron-nucleus total and reaction cross sections for several nuclei. We have applied an analytical model, the nuclear Ramsauer model, justified it from the nuclear reaction theory approach, and extracted the values of 12 parameters used in the model. The given parametrization has an advantage as phenomenological optical model potentials are limited up to 150-200 MeV. The present model provides good estimates of the total cross sections for several nuclei particularly at high energies.

  1. Radiation-induced brain injury: A review

    PubMed Central

    Greene-Schloesser, Dana; Robbins, Mike E.; Peiffer, Ann M.; Shaw, Edward G.; Wheeler, Kenneth T.; Chan, Michael D.

    2012-01-01

    Approximately 100,000 primary and metastatic brain tumor patients/year in the US survive long enough (>6 months) to experience radiation-induced brain injury. Prior to 1970, the human brain was thought to be highly radioresistant; the acute CNS syndrome occurs after single doses >30 Gy; white matter necrosis occurs at fractionated doses >60 Gy. Although white matter necrosis is uncommon with modern techniques, functional deficits, including progressive impairments in memory, attention, and executive function have become important, because they have profound effects on quality of life. Preclinical studies have provided valuable insights into the pathogenesis of radiation-induced cognitive impairment. Given its central role in memory and neurogenesis, the majority of these studies have focused on the hippocampus. Irradiating pediatric and young adult rodent brains leads to several hippocampal changes including neuroinflammation and a marked reduction in neurogenesis. These data have been interpreted to suggest that shielding the hippocampus will prevent clinical radiation-induced cognitive impairment. However, this interpretation may be overly simplistic. Studies using older rodents, that more closely match the adult human brain tumor population, indicate that, unlike pediatric and young adult rats, older rats fail to show a radiation-induced decrease in neurogenesis or a loss of mature neurons. Nevertheless, older rats still exhibit cognitive impairment. This occurs in the absence of demyelination and/or white matter necrosis similar to what is observed clinically, suggesting that more subtle molecular, cellular and/or microanatomic modifications are involved in this radiation-induced brain injury. Given that radiation-induced cognitive impairment likely reflects damage to both hippocampal- and non-hippocampal-dependent domains, there is a critical need to investigate the microanatomic and functional effects of radiation in various brain regions as well as their

  2. An infrared radiation based thermal biosensor for enzymatic biochemical reactions.

    PubMed

    Zhang, Lei; Dong, Tao; Zhao, Xinyan; Yang, Zhaochu; Pires, Nuno M M

    2012-01-01

    In this paper, a thermal biosensor based on the infrared radiation energy is proposed for calorimetric measurement of biochemical reactions. Having a good structure design combined with MEMS technology as well as employing the Si /SiGe quantum well sensing material with a high TCR and low 1/f noise, the sensor shows potentials to be high sensitive and real-time. The urea enzymatic reaction was tested to verify the performance of sensor, which demonstrates a linear detection range from 0.5mM to 150mM and a relative standard deviation less than 1%. For the sensor fabrication, wafer-level transfer bonding is a key process, which makes the integration of quantum well material and a free standing structure possible. It reduces the heat loss from the sensor to the surrounding environment. PMID:23365944

  3. Covariant worldline numerics for charge motion with radiation reaction

    SciTech Connect

    Harvey, Chris; Heinzl, Thomas; Iji, Nicola; Langfeld, Kurt

    2011-04-01

    We develop a numerical formulation to calculate the classical motion of charges in strong electromagnetic fields, such as those occurring in high-intensity laser beams. By reformulating the dynamics in terms of SL(2,C) matrices representing the Lorentz group, our formulation maintains explicit covariance, in particular, the mass-shell condition. Considering an electromagnetic plane wave field where the analytic solution is known as a test case, we demonstrate the effectiveness of the method for solving both the Lorentz force and the Landau-Lifshitz equations. The latter, a second order reduction of the Lorentz-Abraham-Dirac equation, describes radiation reaction without the usual pathologies.

  4. Nuclear Astrophysics and Neutron Induced Reactions: Quasi-Free Reactions and RIBs

    SciTech Connect

    Cherubini, S.; Spitaleri, C.; Crucilla, V.; Gulino, M.; La Cognata, M.; Lamia, L.; Pizzone, R. G.; Puglia, S.; Rapisarda, G. G.; Romano, S.; Sergi, M. L.; Coc, A.; Kubono, S.; Binh, D. N.; Hayakawa, S.; Wakabayashi, Y.; Yamaguchi, H.; Burjan, V.; Kroha, V.; De Sereville, N.

    2010-08-12

    The use of quasi-free reactions in studying nuclear reactions between charged particles of astrophysical interest has received much attention over the last two decades. The Trojan Horse Method is based on this approach and it has been used to study a number of reactions relevant for Nuclear Astrophysics. Recently we applied this method to the study of nuclear reactions that involve radioactive species, namely to the study of the {sup 18}F+p{yields}{sup 15}O+{alpha} process at temperatures corresponding to the energies available in the classical novae scenario. Quasi-free reactions can also be exploited to study processes induced by neutrons. This technique is particularly interesting when applied to reaction induced by neutrons on unstable short-lived nuclei. Such processes are very important in the nucleosynthesis of elements in the sand r-processes scenarios and this technique can give hints for solving key questions in nuclear astrophysics where direct measurements are practically impossible.

  5. Delayed Radiation-Induced Vasculitic Leukoencephalopathy

    SciTech Connect

    Rauch, Philipp J.; Park, Henry S.; Knisely, Jonathan P.S.; Chiang, Veronica L.; Vortmeyer, Alexander O.

    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.

  6. Alpha-induced reactions in iridium

    SciTech Connect

    Bhardwaj, M.K.; Rizvi, I.A.; Chaubey, A.K. )

    1992-05-01

    The excitation function of ({alpha},{ital xn}) reactions on {sup 191}Ir (abundance 37.3%) and on {sup 193}Ir (abundance 62.7%) has been measured for the 17--55 MeV alpha-particle bombarding energy range. The stacked foil activation technique and {gamma}-ray spectroscopy were used to determine the cross sections. The experimental data were compared with calculated values obtained by means of a geometry-dependent hybrid model. The initial exciton number {ital n}{sub 0}=4 with {ital n}=2, {ital p}=2, and {ital h}=0 gives the best agreements with the presently measured results. To calculate the excitation function theoretically a computer code was used. This set of excitation functions provides a data basis for probing the validity of combined equilibrium and preequilibrium reaction models in a considerable energy range.

  7. Ionizing Radiation-induced Diseases in Korea

    PubMed Central

    Jeong, Meeseon; Moon, Kieun; Jo, Min-Heui; Kang, Seong-Kyu

    2010-01-01

    Radiation risk has become well known through epidemiological studies of clinically or occupationally exposed populations, animal experiments, and in vitro studies; however, the study of radiation related or induced disease has been limited in Korea. This study is to find the level of occupational radiation exposure for various kinds of accidents, compensated occupational diseases, related studies, and estimations on future occupational disease risks. Research data of related institutions were additionally investigated. About 67% of 62,553 radiation workers had no exposure or less than 1.2 mSv per year. The 5 reported cases on radiation accident patients in Korea occurred during nondestructive testing. According to the recent rapid increase in the number of workers exposed to radiation, a higher social recognition of cancer, and an increasing cancer mortality rate, it is expected that occupational disease compensation will rapidly increase as well. Therefore, it is important to develop scientific and objective decision methods, such as probability of causation and screening dose in the establishment of an exposure and health surveillance system. PMID:21258594

  8. Ionizing radiation induces human intercellular adhesion molecule-1 in vitro.

    PubMed

    Behrends, U; Peter, R U; Hintermeier-Knabe, R; Eissner, G; Holler, E; Bornkamm, G W; Caughman, S W; Degitz, K

    1994-11-01

    Intercellular adhesion molecule-1 (ICAM-1) plays a central role in various inflammatory reactions and its expression is readily induced by inflammatory stimuli such as cytokines or ultraviolet irradiation. We have investigated the effect of ionizing radiation (IR) on human ICAM-1 expression in human cell lines and skin cultures. ICAM-1 mRNA levels in HL60, HaCaT, and HeLa cells were elevated at 3-6 h after irradiation and increased with doses from 10-40 Gy. The rapid induction of ICAM-1 occurred at the level of transcription, was independent of de novo protein synthesis, and did not involve autocrine stimuli including tumor necrosis factor-alpha and interleukin-1. IR also induced ICAM-1 cell surface expression within 24 h. Immunohistologic analysis of cultured human split skin revealed ICAM-1 upregulation on epidermal keratinocytes and dermal microvascular endothelial cells 24 h after exposure to 6 Gy. In conclusion, we propose ICAM-1 as an important radiation-induced enhancer of immunologic cell adhesion, which contributes to inflammatory reactions after local and total body irradiation. PMID:7963663

  9. Radiation-induced collisional pumping of molecules containing few atoms

    SciTech Connect

    Vasil'ev, G.K.; Chernyshev, Y.A.; Makarov, E.F.; Yakushev, V.G.

    1986-01-01

    The authors analyze the radiation-induced collisional pumping of few-atom molecules by laser emission taking into account both collisional and noncollisional processes of vibrational energy transfer in a molecule. For typical values of the parameters the vibrational energy of the molecules was found to depend on the laser emission intensity; regions of weak absorption, optimum absorption, and saturation appear as the pumping rate rises. Qualitative general conclusions are reached concerning the optimum conditions for the realization, in a medium absorbing laser emission, of either nonequilibrium dissociation or a chemical reaction involving vibrationally excited molecules.

  10. Laser-induced reactions in energetic materials

    NASA Astrophysics Data System (ADS)

    Ling, Ping

    1999-07-01

    Several energetic materials have been investigated under shock wave loading, heating, and photodissociation. This dissertation highlights some efforts to understand energetic material from an angle of basic physical processes and elementary chemical reactions. The first series of experiments was performed to study laser-generated shock waves in energetic materials. Shock waves are generated by pulsed laser vaporization of thin aluminum films. The rapidly expanding aluminum plasma launches a shock wave into the adjacent layer of energetic material, initiating chemical reactions. The shock velocity has been measured by a velocity interferometer. Shock pressures as high as 8 GPa have been generated in this manner. A simple model is proposed to predict laser-generated shock pressure. Several energetic materials have been studied under laser- generated shock wave. The second series of experiments was conducted to study thermal decomposition and photodissociation of energetic materials. Glycidyl azide polymer (GAP) and poly(glycidyl nitrate) (PGN) have been investigated by pulsed infrared laser pyrolysis and ultraviolet laser photolysis of thin films at 17-77 K. Reactions are monitored by transmission infrared spectroscopy. Photolysis of GAP at 266 nm shows that the initial reaction steps are elimination of molecular nitrogen with subsequent formation of imines. Thermal decomposition of GAP by infrared laser pyrolysis reveals products similar to the UV experiments after warming. Laser pyrolysis of PGN indicated that the main steps of decomposition are elimination of NO2 and CH2O from the nitrate ester functional group. It seems that the initial thermal decomposition mechanism of GAP and PGN are the same from heating rate of several degrees per second to 107 oC/s. The third series of experiments is about detailed study of photodissociation mechanism of methyl nitrate. Photodissociation of methyl nitrate isolated in an argon matrix at 17 K has been investigated by 266 nm

  11. Computational Catalysis Using the Artificial Force Induced Reaction Method.

    PubMed

    Sameera, W M C; Maeda, Satoshi; Morokuma, Keiji

    2016-04-19

    The artificial force induced reaction (AFIR) method in the global reaction route mapping (GRRM) strategy is an automatic approach to explore all important reaction paths of complex reactions. Most traditional methods in computational catalysis require guess reaction paths. On the other hand, the AFIR approach locates local minima (LMs) and transition states (TSs) of reaction paths without a guess, and therefore finds unanticipated as well as anticipated reaction paths. The AFIR method has been applied for multicomponent organic reactions, such as the aldol reaction, Passerini reaction, Biginelli reaction, and phase-transfer catalysis. In the presence of several reactants, many equilibrium structures are possible, leading to a number of reaction pathways. The AFIR method in the GRRM strategy determines all of the important equilibrium structures and subsequent reaction paths systematically. As the AFIR search is fully automatic, exhaustive trial-and-error and guess-and-check processes by the user can be eliminated. At the same time, the AFIR search is systematic, and therefore a more accurate and comprehensive description of the reaction mechanism can be determined. The AFIR method has been used for the study of full catalytic cycles and reaction steps in transition metal catalysis, such as cobalt-catalyzed hydroformylation and iron-catalyzed carbon-carbon bond formation reactions in aqueous media. Some AFIR applications have targeted the selectivity-determining step of transition-metal-catalyzed asymmetric reactions, including stereoselective water-tolerant lanthanide Lewis acid-catalyzed Mukaiyama aldol reactions. In terms of establishing the selectivity of a reaction, systematic sampling of the transition states is critical. In this direction, AFIR is very useful for performing a systematic and automatic determination of TSs. In the presence of a comprehensive description of the transition states, the selectivity of the reaction can be calculated more accurately

  12. Radiation-induced autophagy: mechanisms and consequences.

    PubMed

    Chaurasia, Madhuri; Bhatt, Anant Narayan; Das, Asmita; Dwarakanath, Bilikere S; Sharma, Kulbhushan

    2016-01-01

    Autophagy is an evolutionary conserved, indispensable, lysosome-mediated degradation process, which helps in maintaining homeostasis during various cellular traumas. During stress, a context-dependent role of autophagy has been observed which drives the cell towards survival or death depending upon the type, time, and extent of the damage. The process of autophagy is stimulated during various cellular insults, e.g. oxidative stress, endoplasmic reticulum stress, imbalances in calcium homeostasis, and altered mitochondrial potential. Ionizing radiation causes ROS-dependent as well as ROS-independent damage in cells that involve macromolecular (mainly DNA) damage, as well as ER stress induction, both capable of inducing autophagy. This review summarizes the current understanding on the roles of oxidative stress, ER stress, DNA damage, altered mitochondrial potential, and calcium imbalance in radiation-induced autophagy as well as the merits and limitations of targeting autophagy as an approach for radioprotection and radiosensitization. PMID:26764568

  13. Radiation-induced mutation at minisatellite loci

    SciTech Connect

    Dubrova, Y.E. |; Nesterov, V.N.; Krouchinsky, N.G.

    1997-10-01

    We are studying the radiation-induced increase of mutation rate in minisatellite loci in mice and humans. Minisatellite mutations were scored by multilocus DNA fingerprint analysis in the progeny of {gamma}-irradiated and non-irradiated mice. The frequency of mutation in offspring of irradiated males was 1.7 higher that in the control group. Germline mutation at human minisatellite loci was studied among children born in heavily polluted areas of the Mogilev district of Belarus after the Chernobyl accident and in a control population. The frequency of mutation assayed both by DNA fingerprinting and by eight single locus probes was found to be two times higher in the exposed families than in the control group. Furthermore, mutation rate was correlated with the parental radiation dose for chronic exposure {sup 137}Cs, consistent with radiation-induction of germline mutation. The potential use of minisatellites in monitoring germline mutation in humans will be discussed.

  14. Shock-induced reaction synthesis (SRS) of nickel aluminides

    SciTech Connect

    Thadhani, N.N.; Work, S. , New Mexico Tech, Socorro, New Mexico 87801 ); Graham, R.A.; Hammetter, W.F. )

    1992-05-01

    Shock-induced chemical reactions between nickel and aluminum powders (mixed in Ni{sub 3}Al stoichiometry) are used for the synthesis of nickel aluminides. It is shown that the extent of shock-induced chemical reactions and the nature of the shock-synthesized products are influenced by the morphology of the starting powders. Irregular (flaky type) and fine morphologies of the powders undergo complete reactions in contrast to partial reactions occurring in coarse and uniform morphology powders under identical shock loading conditions. Furthermore, irregular morphology powders result in the formation of the equiatomic (B2 phase) NiAl compound while the Ni{sub 3}Al (L1{sub 2} phase) compound is the reaction product with coarse and regular morphology powders. Shock-induced reaction synthesis can be characterized as a bulk reaction process involving an intense mechanochemical'' mechanism. It is a process in which shock compression induces fluid-like plastic flow and mixing, and enhances the reactivity due to the introduction of defects and cleansing of particle surfaces, which strongly influence the synthesis process.

  15. Study of chemical and radiation induced carcinogenesis

    SciTech Connect

    Chmura, A.

    1995-11-01

    The study of chemical and radiation induced carcinogenesis has up to now based many of its results on the detection of genetic aberrations using the fluorescent in situ hybridization (FISH) technique. FISH is time consuming and this tends to hinder its use for looking at large numbers of samples. We are currently developing new technological advances which will increase the speed, clarity and functionality of the FISH technique. These advances include multi-labeled probes, amplification techniques, and separation techniques.

  16. Mouse models for radiation-induced cancers.

    PubMed

    Rivina, Leena; Davoren, Michael J; Schiestl, Robert H

    2016-09-01

    Potential ionising radiation exposure scenarios are varied, but all bring risks beyond the simple issues of short-term survival. Whether accidentally exposed to a single, whole-body dose in an act of terrorism or purposefully exposed to fractionated doses as part of a therapeutic regimen, radiation exposure carries the consequence of elevated cancer risk. The long-term impact of both intentional and unintentional exposure could potentially be mitigated by treatments specifically developed to limit the mutations and precancerous replication that ensue in the wake of irradiation The development of such agents would undoubtedly require a substantial degree of in vitro testing, but in order to accurately recapitulate the complex process of radiation-induced carcinogenesis, well-understood animal models are necessary. Inbred strains of the laboratory mouse, Mus musculus, present the most logical choice due to the high number of molecular and physiological similarities they share with humans. Their small size, high rate of breeding and fully sequenced genome further increase its value for use in cancer research. This chapter will review relevant m. musculus inbred and F1 hybrid animals of radiation-induced myeloid leukemia, thymic lymphoma, breast and lung cancers. Method of cancer induction and associated molecular pathologies will also be described for each model. PMID:27209205

  17. Lack of photoprotection against UVB-induced erythema by immediate pigmentation induced by 382 nm radiation

    SciTech Connect

    Black, G.; Matzinger, E.; Gange, R.W.

    1985-11-01

    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: UVB followed by IPD induction; IPD induction followed by UVB; IPD induction followed 3 h later by UVB; and UVB only. Erythema responses induced by UVB were graded by inspection 24 h later and the MEDs in the 4 areas were compared. The induction of IPD before UVB exposure caused no significant change in the MED compared to sites receiving UVB only, or receiving UVA radiation after UVB, confirming that the IPD reaction does not protect against UVB-induced erythema. There was also no evidence of photorecovery, i.e., an increase in the MED of UVB resulting from exposure to longer wavelength, UV or visible radiation following UVB exposure.

  18. Cinnamon-induced Oral Mucosal Contact Reaction

    PubMed Central

    Vivas, Ana P. M; Migliari, Dante A

    2015-01-01

    Contact stomatitis associated with consumption of cinnamon flavoring agents is a relatively uncommon disorder. Of relevance, both clinical features and the histopathologic findings of this condition are nonspecific, and, more importantly, may resemble some other inflammatory oral mucosa disorders, eventually making diagnosis difficult. Usually a patient exhibits a combination of white and erythematous patches of abrupt onset, accompanied by a burning sensation. To shed some light on this subject, a case of a 64-year-old woman with hypersensitivity contact reaction on the oral mucosa due to cinnamon mints is presented, with emphasis on differential diagnosis and the process for confirmation of the diagnosis. The treatment consists of discontinuing the use of cinnamon products. Clinicians will be able to recognize this disorder following a careful clinical examination and detailed history. This recognition is important in order to avoid invasive and expensive diagnostic procedures. PMID:26312097

  19. Radiation abolishes inducer binding to lactose repressor.

    PubMed

    Gillard, Nathalie; Spotheim-Maurizot, Mélanie; Charlier, Michel

    2005-04-01

    The lactose operon functions under the control of the repressor-operator system. Binding of the repressor to the operator prevents the expression of the structural genes. This interaction can be destroyed by the binding of an inducer to the repressor. If ionizing radiations damage the partners, a dramatic dysfunction of the regulation system may be expected. We showed previously that gamma irradiation hinders repressor-operator binding through protein damage. Here we show that irradiation of the repressor abolishes the binding of the gratuitous inducer isopropyl-1-beta-D-thiogalactoside (IPTG) to the repressor. The observed lack of release of the repressor from the complex results from the loss of the ability of the inducer to bind to the repressor due to the destruction of the IPTG binding site. Fluorescence measurements show that both tryptophan residues located in or near the IPTG binding site are damaged. Since tryptophan damage is strongly correlated with the loss of IPTG binding ability, we conclude that it plays a critical role in the effect. A model was built that takes into account the kinetic analysis of damage production and the observed protection of its binding site by IPTG. This model satisfactorily accounts for the experimental results and allows us to understand the radiation-induced effects. PMID:15799700

  20. Genistein mitigates radiation-induced testicular injury.

    PubMed

    Kim, Joong-Sun; Heo, Kyu; Yi, Joo-Mi; Gong, Eun Ji; Yang, Kwangmo; Moon, Changjong; Kim, Sung-Ho

    2012-08-01

    The present study investigated the radioprotective effect of a multifunctional soy isoflavone, genistein, with the testicular system. Genistein was administered (200 mg/kg body weight) to male C3H/HeN mice by subcutaneous injection 24 h prior to pelvic irradiation (5 Gy). Histopathological parameters were evaluated 12 h and 21 days post-irradiation. Genistein protected the germ cells from radiation-induced apoptosis (p < 0.05 vs vehicle-treated irradiated mice at 12 h post-irradiation). Genistein significantly attenuated radiation-induced reduction in testis weight, seminiferous tubular diameter, seminiferous epithelial depth and sperm head count in the testes (p < 0.05 vs vehicle-treated irradiated mice at 21 days post-irradiation). Repopulation and stem cell survival indices of the seminiferous tubules were increased in the genistein-treated group compared with the vehicle-treated irradiation group at 21 days post-irradiation (p < 0.01). The irradiation-mediated decrease in the sperm count and sperm mobility in the epididymis was counteracted by genistein (p < 0.01), but no effect on the frequency of abnormal sperm was evident. Reactive oxygen species (ROS) were evaluated using DCFDA method and exposure to irradiation elevated ROS levels in the testis and genistein treatment resulted in a significant attenuation of radiation-induced ROS production. The results indicate that genistein protects from testicular dysfunction induced by gamma-irradiation by an antiapoptotic effect and recovery of spermatogenesis. PMID:22162311

  1. Pre-irradiation-induced graft reaction of maleic anhydride onto polypropylene

    NASA Astrophysics Data System (ADS)

    Tan, X. M.; Xu, Y. S.; Wang, C. L.

    2006-09-01

    The radiation induced graft polymerization is a well-known method to obtain new materials. Until recently, only conventional radiation sources, such as Co-60 and electron beams, were used. Moreover, part of the damage induced in polymers by heavy ions can produce active sites (peroxides and hydroperoxides) that are useful to initiate grafting reactions. Maleic anhydride (MAH) was grafted onto polypropylene (PP) wax with a number-average molecular weight (Mn) of 8000 by gamma pre-irradiation technique. Effects of total dose, monomer concentration, reaction time, and temperature on percentage of grafting are studied in detail. It is shown that the optimum conditions for grafting are temperature of 70 degrees C and total dose of 14.4 kGy. PP-g-MAH is characterized by infrared spectrum. Differential scanning calorimetry shows that the compatibility of PP-g-MAH is better than that of PP.

  2. 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

  3. Kinetic studies of the infrared-induced reaction between atomic chlorine and solid parahydrogen

    NASA Astrophysics Data System (ADS)

    Raston, Paul L.; Kettwich, Sharon C.; Anderson, David T.

    2015-04-01

    We present Fourier-transform infrared (FTIR) spectroscopic studies of the IR-induced Cl + H2(v = 1) → HCl + H reaction in a parahydrogen (pH2) matrix aimed at distinguishing between two proposed reactions mechanisms; direct-IR and vibron-mediated. The Cl atom reactants are produced via 355 nm in situ photolysis of a Cl2 doped pH2 matrix. After photolysis is complete, a long-pass IR filter in the FTIR beam is removed and we measure the ensuing IR-induced reaction kinetics using rapid scan FTIR spectroscopy. We follow both the decay of the Cl atom reactant and growth of the HCl product using the Cl spin-orbit (SO) + Q1(0) and HCl R1(0) transitions, respectively. We show the IR-induced reaction mechanism depends on the spectral profile of the IR radiation; for IR spectral profiles that have significant IR intensities between 4000 and 5000 cm-1 we observe first-order kinetics that are assigned to a vibron-mediated mechanism and for spectral profiles that have significant IR intensities that include the Cl SO + Q1(0) transition near 5094 cm-1 we observe bi-exponential kinetics that are dominated by the direct-IR mechanism at early reaction times. We can distinguish between the two mechanisms using the observed kinetics. We investigate the reaction kinetics for different FTIR optical setups, for a range of sample conditions, and start and stop the IR-induced reaction to investigate the importance of secondary H atom reactions. We also study the IR-induced reaction in Br/Cl co-doped pH2 samples and show the presence of the Br atom quenches the vibron-mediated reaction kinetics presumably because the Br-atoms serve as efficient vibron traps. This paper indicates that in a highly enriched pH2 matrix the H atoms that are produced by the IR-induced Cl atom reaction likely do not play a significant role in the measured reaction kinetics which implies these secondary H atom reactions are highly selective.

  4. Estrogen Protects against Radiation-Induced Cataractogenesis

    PubMed Central

    Dynlacht, Joseph R.; Valluri, Shailaja; Lopez, Jennifer; Greer, Falon; DesRosiers, Colleen; Caperell-Grant, Andrea; Mendonca, Marc S.; Bigsby, Robert M.

    2008-01-01

    Cataractogenesis is a complication of radiotherapy when the eye is included in the treatment field. Low doses of densely ionizing space radiation may also result in an increased risk of cataracts in astronauts. We previously reported that estrogen (17-β-estradiol), when administered to ovariectomized rats commencing 1 week before γ irradiation of the eye and continuously thereafter, results in a significant increase in the rate and incidence of cataract formation and a decreased latent period compared to an ovariectomized control group. We therefore concluded that estrogen accelerates progression of radiation-induced opacification. We now show that estrogen, if administered continuously, but commencing after irradiation, protects against radiation cataractogenesis. Both the rate of progression and incidence of cataracts were greatly reduced in ovariectomized rats that received estrogen treatment after irradiation compared to ovariectomized rats. As in our previous study, estradiol administered 1 week prior to irradiation at the time of ovariectomy and throughout the period of observation produced an enhanced rate of cataract progression. Estrogen administered for only 1 week prior to irradiation had no effect on the rate of progression but resulted in a slight reduction in the incidence. We conclude that estrogen may enhance or protect against radiation cataractogenesis, depending on when it is administered relative to the time of irradiation, and may differentially modulate the initiation and progression phases of cataractogenesis. These data have important implications for astronauts and radiotherapy patients. PMID:19138041

  5. Impact of phonon coupling on the radiative nuclear reaction characteristics

    NASA Astrophysics Data System (ADS)

    Achakovskiy, Oleg; Avdeenkov, Alexander; Kamerdzhiev, Sergei

    2016-01-01

    The pygmy dipole resonance and photon strength functions (PSF) in stable and unstable Ni and Sn isotopes are calculated within the microscopic self-consistent version of the extended theory of finite Fermi systems in the quasiparticle time blocking approximation. The approach includes phonon coupling (PC) effects in addition to the standard QRPA approach. The Skyrme force SLy4 is used. A pygmy dipole resonance in 72Ni is predicted at the mean energy of 12.4 MeV exhausting 25.7% of the total energy-weighted sum rule. With our microscopic E1 PSFs in the EMPIRE 3.1 code, the following radiative nuclear reaction characteristics have been calculated for several stable and unstable even-even Sn and Ni isotopes: 1) neutron capture cross sections, 2) corresponding neutron capture gamma-spectra, 3) average radiative widths of neutron resonances. Here, three variants of the microscopic nuclear level density models have been used and a comparison with the phenomenological generalized superfluid model has been performed. In all the considered properties, including the recent experimental data for PSF in Sn isotopes, the PC contributions turned out to be significant, as compared with the QRPA one, and necessary to explain the available experimental data.

  6. r-mode instability: Analytical solution with gravitational radiation reaction

    SciTech Connect

    Dias, Oscar J.C.; Sa, Paulo M.

    2005-07-15

    Analytical r-mode solutions are investigated within the linearized theory in the case of a slowly rotating, Newtonian, barotropic, nonmagnetized, perfect-fluid star in which the gravitational radiation (GR) reaction force is present. For the GR reaction term we use the 3.5 post-Newtonian order expansion of the GR force, in order to include the contribution of the current quadrupole moment. We find the explicit expression for the r-mode velocity perturbations and we conclude that they are sinusoidal with the same frequency as the well-known GR force-free linear r-mode solution, and that the GR force drives the r-modes unstable with a growth time scale that agrees with the expression first found by Lindblom, Owen, and Morsink. We also show that the amplitude of these velocity perturbations is corrected, relatively to the GR force-free case, by a term of order {omega}{sup 6}, where {omega} is the angular velocity of the star.

  7. Nuclear reactions induced by high-energy alpha particles

    NASA Technical Reports Server (NTRS)

    Shen, B. S. P.

    1974-01-01

    Experimental and theoretical studies of nuclear reactions induced by high energy protons and heavier ions are included. Fundamental data needed in the shielding, dosimetry, and radiobiology of high energy particles produced by accelerators were generated, along with data on cosmic ray interaction with matter. The mechanism of high energy nucleon-nucleus reactions is also examined, especially for light target nuclei of mass number comparable to that of biological tissue.

  8. Deuterium separation by infrared-induced addition reaction

    DOEpatents

    Marling, John B.

    1977-01-01

    A method for deuterium enrichment by the infrared-induced addition reaction of a deuterium halide with an unsaturated aliphatic compound. A gaseous mixture of a hydrogen halide feedstock and an unsaturated aliphatic compound, particularly an olefin, is irradiated to selectively vibrationally excite the deuterium halide contained therein. The excited deuterium halide preferentially reacts with the unsaturated aliphatic compound to produce a deuterated addition product which is removed from the reaction mixture.

  9. Radiation reaction in binary systems in general relativity

    NASA Astrophysics Data System (ADS)

    Kennefick, Daniel John

    1997-09-01

    This thesis is concerned with current problems in, and historical aspects of, the problem of radiation reaction in stellar binary systems in general relativity. Part I addresses current issues in the orbital evolution due to gravitational radiation damping of compact binaries. A particular focus is on the inspiral of small bodies orbiting large black holes, employing a perturbation formalism. In addition, the merger, at the end of the insprial, of comparable mass compact binaries, such as neutron star binaries is also discussed. The emphasis of Part I is on providing detailed descriptions of sources and signals with a view to optimising signal analysis in gravitational wave detectors, whether ground- or space- based interferometers, or resonant mass detectors. Part II of the thesis examines the historical controversies surrounding the problem of gravitational waves, and gravitational radiation damping in stellar binaries. In particular, it focuses on debates in the mid 20th-century on whether binary star systems would really exhibit this type of damping and emit gravitational waves, and on the 'quadrupole formula controversy' of the 1970s and 1980s, on the question whether the standard formular describing energy loss due to emission of gravitational waves was correctly derived for such systems. The study shed light on the role of analogy in science, especially where its use is controversial, on the importance of style in physics and on the problem of identity in science, as the use of history as a rhetorical device in controversial debate is examined. The concept of the Theoretician's Regress is introduced to explain the difficulty encountered by relativists in closing debate in this controversy, which persisted in one forms or another for several decades.

  10. 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.

  11. Photo- and neutrino-induced reactions for SNe nucleosynthesis

    NASA Astrophysics Data System (ADS)

    Shima, Tatsushi

    2014-09-01

    Neutrino-induced nuclear reactions are considered to play important roles in the dynamics of supernova explosions and in supernova nucleosynthesis. For example, neutrino-inelastic scattering off light nuclei are supposed to assist the explosion by supplying the kinetic energy to the outgoing matters. The neutrino-nucleus reactions via the neutral and charged current of the weak interaction are the key reactions in the r-process nucleosynthesis in neutrino-driven wind. To quantitatively understand those phenomena, precise data of the neutrino-nucleus reaction rates are indispensable. Recently developed secondary particle beams provide good experimental opportunities for determining the neutrino-nucleus reaction rates. A quasi-monochromatic laser Compton-scattered (LCS) photon beam is useful for studying the photonuclear reactions which are the direct analogue of the neutrino inelastic scatterings caused by the weak neutral current. On the other hand, real neutrino beams are ideal tools to directly measure the absolute neutrino-nucleus reaction rates. Another interesting probe will be the nuclear muon-capture reaction, because it can be applied for measurement of the targets with very small quantities thanks to its large capture probability. In this talk recent progress in ongoing experiments with LCS gamma-rays and muon beams will be presented. A new plan for direct measurement of the neutrino-nucleus reactions with an accelerator-driven neutrino beam will be also discussed.

  12. Broad-spectrum moisturizer effectively prevents molecular reactions to UVA radiation.

    PubMed

    Seité, Sophie; Reinhold, Katja; Jaenicke, Thomas; Brenden, Heidi; Krutmann, Jean; Grether-Beck, Susanne

    2012-12-01

    The damaging effects of UVA radiation have been well-documented. UVA radiation is known to induce molecular, cellular, and clinical damage. Such harm may lead to photoaging, immune system depression, altered gene expression, or oncogene and tumor suppressor gene modulation, all of which are partly responsible for the development of skin cancer. In parallel to an increased understanding of the added damage caused by UVA radiation, progress has been made in sunscreen formulation. A variety of UVA filters are now available for formulators to combine with UVB filters to reach high-level photostable protection using a minimum concentration of active ingredients. The efficacy of products that contain these UV filter combinations usually is determined by noninvasive assessments, which cause either UVA-induced erythema or skin pigmentation. However, the biologic relevance of these end points for UVA radiation-induced skin damage is unknown. In our study, we confirm that the assessment of UVA radiation-induced gene expression in skin specimens obtained from UVA-irradiated human skin by quantitative real-time polymerase chain reaction is a sensitive, reliable, and robust method to prove the efficacy of 2 daily moisturizers containing broad-spectrum sunscreen. Specifically, we demonstrate in vivo that topical application of a daily moisturizer with broad-spectrum sunscreen prevents UVA radiation-induced transcriptional expression of genes that are directly linked to skin aging (ie, matrix metalloproteinase 1 [MMP-1]) and also reflect the skin's antioxidative stress defense response (ie, catalase [CAT], superoxide dismutase [SOD], glutathione peroxidase [GPx]). Furthermore, we demonstrate that the protection against UV-induced skin damage provided by products with different sun protection factor (SPF) but the same UVA protection factor (UVA-PF) is similar, which emphasizes the importance of high UVA protection to maintain unaltered essential biologic functions. These data

  13. Thermally Induced And Base Catalyzed Reactions Of Naphthoquinone Diazides

    NASA Astrophysics Data System (ADS)

    Koshiba, Mitsunobu; Murata, Makoto; Matsui, Mariko; Harita, Yoshiyuki

    1988-01-01

    Thermally induced and base catalyzed reactions of a phenol ester of 1,2-naphthoquinone-diazide-5-sulfonic acid (DAM) with p-cresol were investigated. In total seven reaction products were obtained for the thermally induced reaction. The three major products, TR--F4, TR-F6 and TR-F7, were isolated and their structures were determined by means of several advanced spectroscopic techniques like Fourier transform nuclear magnetic resonance (FTNMR) and field desorption mass spectroscopy (FD-MS). Besides a cresol ester of indenecarboxylic acid (TR-F6) and an azo compound which contains two DAM originated moieties and cresol (TR-F7), the formation of a novel compound was found; a phenol ester of 2-cresyl-l-naphthol-5-sulfonic acid. On the other hand, four reaction products were found in the base (a 2.38wt% tetramethylammonium hydroxide aq. solution) catalyzed reaction products of DAM with p-cresol, and two major products, BC-Fl and BC-F3, which appeared at the initial stage of the reaction were isolated. The structure determination of the two major products was carried out in the same manner as described above. It was discovered that BC-Fl was a cresol ester of 1-naphthol while BC-F3 was an azoxy compound. Brief discussions will be made on those reactions of naphthoquinone diazides with a matrix novolak resin with reference to the results obtained by the present study.

  14. The use of low energy, ion induced nuclear reactions for proton radiotherapy applications

    SciTech Connect

    Horn, K.M.; Doyle, B.; Segal, M.N.; Hamm, R.W.; Adler, R.J.; Glatstein, E.

    1995-04-01

    Medical radiotherapy has traditionally relied upon the use of external photon beams and internally implanted radioisotopes as the chief means of irradiating tumors. However, advances in accelerator technology and the exploitation of novel means of producing radiation may provide useful alternatives to some current modes of medical radiation delivery with reduced total dose to surrounding healthy tissue, reduced expense, or increased treatment accessibility. This paper will briefly overview currently established modes of radiation therapy, techniques still considered experimental but in clinical use, innovative concepts under study that may enable new forms of treatment or enhance existing ones. The potential role of low energy, ion-induced nuclear reactions in radiotherapy applications is examined specifically for the 650 keV d({sup 3}He,p){sup 4}He nuclear reaction. This examination will describe the basic physics associated with this reaction`s production of 17.4 MeV protons and the processes used to fabricate the necessary materials used in the technique. Calculations of the delivered radiation dose, heat generation, and required exposure times are presented. Experimental data are also presented validating the dose calculations. The design of small, lower cost ion accelerators, as embodied in `nested`-tandem and radio frequency quadrupole accelerators is examined, as is the potential use of high-output {sup 3}He and deuterium ion sources. Finally, potential clinical applications are discussed in terms of the advantages and disadvantages of this technique with respect to current radiotherapy methods and equipment.

  15. [Reaction mechanism studies of heavy ion induced nuclear reactions]. Annual progress report, [January 1992--February 1993

    SciTech Connect

    Mignerey, A.C.

    1993-02-01

    Completed work is summarized on the topics of excitation energy division in deep-inelastic reactions and the onset of multifragmentation in La-induced reactions at E/A = 45 MeV. Magnetic fields are being calculated for the PHOBOS detector system, a two-arm multiparticle spectrometer for studying low-transverse-momentum particles produced at the Relativistic Heavy Ion Collider. The Maryland Forward Array is being developed for detection of the reaction products from very peripheral collisions; it consists of two individual units of detectors: the annular silicon detector in front and the plastic phoswich detector at back.

  16. On reaction mechanisms involved in the deuteron–induced surrogate reactions

    SciTech Connect

    Avrigeanu, M.; Avrigeanu, V.; Mănăilescu, C.

    2015-02-24

    An extended analysis of the nuclear reaction mechanisms involved within deuteron interaction with nuclei, namely the breakup, stripping, pick-up, pre-equilibrium emission, and evaporation from fully equilibrated compound nucleus, is presented in order to highlight the importance of the direct mechanisms still neglected in the analysis of deuteron-induced surrogate reactions. Particularly, the dominance of the breakup mechanism at low energies around the Coulomb barrier should be considered in the case of (d,x) surrogate reactions on actinide target nuclei.

  17. On reaction mechanisms involved in the deuteron-induced surrogate reactions

    NASA Astrophysics Data System (ADS)

    Avrigeanu, M.; Avrigeanu, V.; Mǎnǎilescu, C.

    2015-02-01

    An extended analysis of the nuclear reaction mechanisms involved within deuteron interaction with nuclei, namely the breakup, stripping, pick-up, pre-equilibrium emission, and evaporation from fully equilibrated compound nucleus, is presented in order to highlight the importance of the direct mechanisms still neglected in the analysis of deuteron-induced surrogate reactions. Particularly, the dominance of the breakup mechanism at low energies around the Coulomb barrier should be considered in the case of (d,x) surrogate reactions on actinide target nuclei.

  18. Radiation-induced osteosarcoma of the sphenoid bone

    SciTech Connect

    Tanaka, S.; Nishio, S.; Morioka, T.; Fukui, M.; Kitamura, K.; Hikita, K. )

    1989-10-01

    The case of a patient who developed osteosarcoma in the sphenoid bone 15 years after radiation therapy for a craniopharyngioma is reported. Radiation-induced osteosarcoma of the sphenoid bone has not been reported previously. Reported cases of radiation-induced osteosarcomas are reviewed.

  19. Radiation induced micrencephaly in guinea pigs

    SciTech Connect

    Wagner, L.K.; Johnston, D.A.; Felleman, D.J.

    1991-01-01

    A brain weight deficit of about 70 mg was induced at doses of approximately 75-mGy and a deficit of 60 mg was induced at 100 mGy. This confirms the effects projected and observed by Wanner and Edwards. Although the data do not demonstrate a clear dose-response relationship between the 75-mGy and 100-mGy groups, the data are statistically consistent with a dose-response effect because of the overlapping confidence intervals. The lack of a statistically significant observation is most likely related to the small difference in doses and the limited numbers of animals examined. There are several factors that can influence the brain weight of guinea pig pups, such as caging and housing conditions, the sex of the animal, and litter size. These should be taken into account for accurate analysis. Dam weight did not appear to have a significant effect. The confirmation of a micrencephalic effect induced x rays at doses of 75-mGy during this late embryonic stage of development is consistent with the findings of small head size induced in those exposed prior to the eight week of conception at Hiroshima. This implies a mechanism for micrencephaly different from those previously suggested and lends credence to a causal relation between radiation and small head size in humans at low doses as reported by Miller and Mulvihill. 16 refs., 13 tabs.

  20. Reaction Rate Theory of Radiation Exposure and Scaling Hypothesis in Mutation Frequency

    NASA Astrophysics Data System (ADS)

    Manabe, Yuichiro; Nakamura, Issei; Bando, Masako

    2014-11-01

    We have developed a kinetic reaction model for cells with irradiated DNA molecules due to ionizing radiation exposure. Our theory simultaneously accounts for the time-dependent reactions of DNA damage, DNA mutation and DNA repair, and the proliferation and apoptosis of cells in a tissue with a minimal set of model parameters. In contrast to existing theories of radiation exposition, we do not assume the relationships between the total dose and the induced mutation frequency. Our theory provides a universal scaling function that reasonably explains the mega-mouse experiments by Russell and Kelly [Proc. Natl. Acad. Sci. U.S.A. 79, 542 (1982)] with different dose rates. Furthermore, we have estimated the effective dose rate, which is biologically equivalent to the ionizing effects other than those caused by artificial irradiation. This value is 1.11 × 10-3 Gy/h, which is significantly larger than the effect caused by natural background radiation.

  1. Radiation-induced uterine changes: MR imaging

    SciTech Connect

    Arrive, L.; Chang, Y.C.; Hricak, H.; Brescia, R.J.; Auffermann, W.; Quivey, J.M.

    1989-01-01

    To assess the capability of magnetic resonance (MR) imaging to demonstrate postirradiation changes in the uterus, MR studies of 23 patients who had undergone radiation therapy were retrospectively examined and compared with those of 30 patients who had not undergone radiation therapy. MR findings were correlated with posthysterectomy histologic findings. In premenopausal women, radiation therapy induced (a) a decrease in uterine size demonstrable as early as 3 months after therapy ended; (b) a decrease in signal intensity of the myometrium on T2-predominant MR images, reflecting a significant decrease in T2 relaxation time, demonstrable as early as 1 month after therapy; (c) a decrease in thickness and signal intensity of the endometrium demonstrable on T2-predominant images 6 months after therapy; and (d) loss of uterine zonal anatomy as early as 3 months after therapy. In postmenopausal women, irradiation did not significantly alter the MR imaging appearance of the uterus. These postirradiation MR changes in both the premenopausal and postmenopausal uteri appeared similar to the changes ordinarily seen on MR images of the nonirradiated postmenopausal uterus.

  2. Tween-80 and impurity induce anaphylactoid reaction in zebrafish.

    PubMed

    Yang, Rui; Lao, Qiao-Cong; Yu, Hang-Ping; Zhang, Yong; Liu, Hong-Cui; Luan, Lin; Sun, Hui-Min; Li, Chun-Qi

    2015-03-01

    A number of recent reports suspected that Tween-80 in injectable medicines, including traditional Chinese medicine injections could cause life-threatening anaphylactoid reaction, but no sound conclusion was drawn. A drug-induced anaphylactoid reaction is hard to be assayed in vitro and in conventional animal models. In this study, we developed a microplate-based quantitative in vivo zebrafish assay for assessing anaphylactoid reaction and live whole zebrafish mast cell tryptase activity was quantitatively measured at a wavelength of 405 nm using N-benzoyl-dl-arginine p-nitroanilide as a substrate. We assessed 10 batches of Tween-80 solutions from various national and international suppliers and three Tween-80 impurities (ethylene glycol, 2-chloroethanol and hydrogen peroxide) in this model and found that three batches of Tween-80 (nos 2, 20080709 and 20080616) and one Tween-80 impurity, hydrogen peroxide (H2 O2 ), induced anaphylactoid reactions in zebrafish. Furthermore, we found that H2 O2 residue and peroxide value were much higher in Tween-80 samples 2, 20080709 and 20080616. These findings suggest that H2 O2 residue in combination with oxidized fatty acid residues (measured as peroxide value) or more likely the oxidized fatty acid residues in Tween-80 samples, but not Tween-80 itself, may induce anaphylactoid reaction. High-throughput zebrafish tryptase assay developed in this report could be used for assessing safety of Tween-80-containing injectable medicines and potentially for screening novel mast cell-modulating drugs. PMID:25345596

  3. Theory Of Radiation-Induced Attenuation In Optical Fibers

    NASA Technical Reports Server (NTRS)

    Liu, Tsuen-Hsi; Johnston, Alan R.

    1996-01-01

    Improved theory of radiation-induced attenuation of light in optical fibers accounts for effects of dose rates. Based on kinetic aspects of fundamental physics of color centers induced in optical fibers by radiation. Induced attenuation is proportional to density of color centers, and part of this density decays by thermal-annealing/recombination process after irradiation.

  4. Energy Distribution of Electrons in Radiation Induced-Helium Plasmas. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Lo, R. H.

    1972-01-01

    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 radiation-induced plasma is of interest in a variety of applications, such as radiation pumped lasers and gaseous core nuclear reactors.

  5. Alpha Induced Reaction Cross Section Calculations of Tantalum Nucleus

    NASA Astrophysics Data System (ADS)

    Tel, E.; Ugur, F. A.; Gokce, A. A.

    2013-04-01

    The fusion energy is attractive as an energy source because the fusion will not produce CO2 or SO2 and so fusion will not contribute to environmental problems, such as particulate pollution and excessive CO2 in the atmosphere. The fusion reaction does not produce radioactive nuclides and it is not self-sustaining, as is a fission reaction when a critical mass of fissionable material is assembled. Since the fusion reaction is easily and quickly quenched the primary sources of heat to drive such an accident are heat from radioactive decay and heat from chemical reactions. Both the magnitude and time dependence of the generation of heat from radioactive decay can be controlled by proper selection and design of materials. Tantalum is one of the candidate materials for the first wall of fusion reactors and for component parts of irradiation chambers. Accurate experimental cross-section data of alpha induced reactions on Tantalum are also of great importance for thermonuclear reaction rate determinations since the models used in the study of stellar nucleosynthesis are strongly dependent on these rates (Santos et al. in J Phys G 26:301, 2000). In this study, neutron-production cross sections for target nuclei 181Ta have been investigated up to 100 MeV alpha energy. The excitation functions for (α, xn) reactions (x = 1, 2, 3) have been calculated by pre-equilibrium reaction mechanism. And also neutron emission spectra for 181Ta (α, xn) reactions at 26.8 and 45.2 MeV have been calculated. The mean free path multiplier parameters has been investigated. The pre-equilibrium results have been calculated by using the hybrid model, the geometry dependent hybrid (GDH) model. Calculation results have been also compared with the available measurements in literature.

  6. Fatal anaphylactoid reaction associated with heparin-induced thrombocytopenia.

    PubMed

    Singla, Atul; Amini, Mohammad R; Alpert, Martin A; Gornik, Heather L

    2013-06-01

    Acute systemic (anaphylaxis and anaphylactoid) reactions have been well described in patients with heparin-induced thrombocytopenia (HIT). Both necrotizing and non-necrotizing skin lesions at heparin injection sites have been reported and may occur in 10-20% of patients with HIT. We report herein a patient treated with subcutaneous enoxaparin sodium who developed non-necrotizing erythematous skin lesions at enoxaparin sodium injection sites. A subsequent intravenous bolus of unfractionated heparin produced a fatal anaphylactoid reaction. This suggests that caution should be exercised in the administration of intravenous heparin to patients with non-necrotizing erythematous skin lesions at prior heparin injection sites. PMID:23579400

  7. Effects of radiation reaction in the interaction between cluster media and high intensity lasers in the radiation dominant regime

    NASA Astrophysics Data System (ADS)

    Iwata, Natsumi; Nagatomo, Hideo; Fukuda, Yuji; Matsui, Ryutaro; Kishimoto, Yasuaki

    2016-06-01

    Interaction between media composed of clusters and high intensity lasers in the radiation dominant regime, i.e., intensity of 10 22 - 23 W / cm 2 , is studied based on the particle-in-cell simulation that includes the radiation reaction. By introducing target materials that have the same total mass but different internal structures, i.e., uniform plasma and cluster media with different cluster radii, we investigate the effect of the internal structure on the interaction dynamics, high energy radiation emission, and its reaction. Intense radiation emission is found in the cluster media where electrons exhibit non-ballistic motions suffering from strong accelerations by both the penetrated laser field and charge separation field of clusters. As a result, the clustered structure increases the energy conversion into high energy radiations significantly at the expense of the conversion into particles, while the total absorption rate into radiation and particles remains unchanged from the absorption rate into particles in the case without radiation reaction. The maximum ion energy achieved in the interaction with cluster media is found to be decreased through the radiation reaction to electrons into the same level with that achieved in the interaction with the uniform plasma. The clustered structure thus enhances high energy radiation emission rather than the ion acceleration in the considered intensity regime.

  8. Heparin-induced anaphylactoid reaction associated with heparin-induced thrombocytopenia in the ED.

    PubMed

    Foreman, Juron S; Daniels, Lauren M; Stettner, Edward A

    2014-12-01

    Although rare, heparin-induced anaphylactic and anaphylactoid reactions have been previously described in the literature. We present a case of a patient who presented to the emergency department with dyspnea and was subsequently diagnosed with an acute pulmonary venous thromboembolism. Shortly after being started on intravenous unfractionated heparin, she developed sudden cardiovascular collapse leading to a cardiopulmonary arrest. She was successfully resuscitated and, after further diagnostic evaluation, was found to have developed a heparin-induced anaphylactoid reaction. PMID:25097093

  9. Radiation-induced degradation of 4-chloroaniline in aqueous solution

    NASA Astrophysics Data System (ADS)

    Sánchez, M.; Wolfger, H.; Getoff, N.

    2002-12-01

    The radiation-induced decomposition of 4-chloroaniline (4-ClA) was studied under steady-state conditions using aqueous solutions saturated with air, pure oxygen, N 2O, argon and argon in the presence of t-Butanol. Using HPLC-method, the initial G-values of the substrate degradation as well as of a number of radiolytic products were determined. The formation of aminophenols, chlorophenols, aniline and phenol in addition to chloride, ammonia, formaldehyde and mixture of aldehydes as well as carboxylic acids was studied as a function of absorbed dose. Based on the experimental data, probable reaction mechanisms for the degradation of 4-ClA by γ-rays and the formation of the identified products are presented.

  10. A systematic review of drug induced ocular reactions in diabetes

    PubMed Central

    Hampson, J; Harvey, J

    2000-01-01

    AIMS—To conduct a systematic review of drug induced adverse ocular effects in diabetes to determine if this approach identified any previously unrecognised adverse drug effects; to make a preliminary assessment of the feasibility of this approach in identifying adverse drug reactions; and to assess the current accessibility of this information to prescribing physicians.
METHODS—Literature search of online biomedical databases. The search strategy linked eye disorders with adverse drug reactions and diabetes. Source journals were classified as medical, pharmaceutical, diabetes related, or ophthalmological. It was determined whether the reactions identified were recorded in drug datasheets and the British National Formulary.
RESULTS—63 references fulfilled the selection criteria, of which 45 were considered to be relevant to the study. The majority of these were case reports but cross sectional surveys, case-control and cohort studies, and review articles were also identified. 61% of the reactions were not recorded in the British National Formulary and 41% were not recorded in the datasheets. 55% appeared in specialist ophthalmology journals.
CONCLUSIONS—This is a feasible approach to the identification of adverse drug reactions. Adverse reactions not listed in the most commonly used reference sources were found. The majority were published in specialist ophthalmology journals which might not be seen by prescribing physicians.

 PMID:10655188

  11. Analog of microwave-induced resistance oscillations induced in GaAs heterostructures by terahertz radiation

    NASA Astrophysics Data System (ADS)

    Herrmann, T.; Dmitriev, I. A.; Kozlov, D. A.; Schneider, M.; Jentzsch, B.; Kvon, Z. D.; Olbrich, P.; Bel'kov, V. V.; Bayer, A.; Schuh, D.; Bougeard, D.; Kuczmik, T.; Oltscher, M.; Weiss, D.; Ganichev, S. D.

    2016-08-01

    We report on the study of terahertz radiation-induced MIRO-like oscillations of magnetoresistivity in GaAs heterostructures. Our experiments provide an answer on two most intriguing questions—effect of radiation helicity and the role of the edges—yielding crucial information for an understanding of the MIRO (microwave-induced resistance oscillations) origin. Moreover, we demonstrate that the range of materials exhibiting radiation-induced magneto-oscillations can be largely extended by using high-frequency radiation.

  12. Gamma-radiation induced changes in the physical and chemical properties of lignocellulose.

    PubMed

    Khan, Ferdous; Ahmad, S R; Kronfli, E

    2006-08-01

    gamma-radiation induced effects on the physical and chemical properties of natural lignocellulose (jute) polymer were investigated. Samples were irradiated to required total doses at a particular dose rate. The changes in the parameters such as the tensile strength, elongation at break, and work done at rupture for the lignocellulose samples on irradiation with the gamma-rays from a cobalt-60 source were measured. The mechanical properties were found to have nonlinear relations with the radiation doses. The chemical stability of irradiated fibers was found to degrade progressively with the increase of radiation dose. Additionally, other chemical changes of the samples due to exposure to high-energy radiation were also investigated using fluorescence and infrared spectroscopic analysis. Differential scanning calorimetry and thermogravimetric studies showed a significant reduction in thermal stability. The wide-angle X-ray diffraction study showed that structural changes of cellulose appeared due to the radiation-induced chemical reaction of lignocellulose. PMID:16903675

  13. 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.

  14. 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.

  15. Discreteness-induced transitions in multibody reaction systems.

    PubMed

    Saito, Yohei; Sughiyama, Yuki; Kaneko, Kunihiko; Kobayashi, Tetsuya J

    2016-08-01

    A decrease in system size can induce qualitatively different behavior compared to the macroscopic behavior of the corresponding large-size system. The mechanisms of this transition, which is known as the small-size transition, can be attributed to either a relative increase in the noise intensity or to the discreteness of the state space due to the small system size. The former mechanism has been intensively investigated using several toy and realistic models. However, the latter has rarely been analyzed and is sometimes confused with the former, because a toy model that extracts the essence of the discreteness-induced transition mechanism is lacking. In this work, we propose a one- and three-body reaction system as a minimal model of the discreteness-induced transition and derive the conditions under which this transition occurs in more complex systems. This work enriches our understanding of the influence of small system size on system behavior. PMID:27627279

  16. Radiation-induced nausea and vomiting

    PubMed Central

    Habibi, Mohsen; Namimoghadam, Amir; Korouni, Roghaye; Fashiri, Paria; Borzoueisileh, Sajad; Elahimanesh, Farideh; Amiri, Fatemeh; Moradi, Ghobad

    2016-01-01

    Abstract Despite the improvements in cancer screening and treatment, it still remains as one of the leading causes of mortality worldwide. Nausea and vomiting as the side effects of different cancer treatment modalities, such as radiotherapy, are multifactorial and could affect the treatment continuation and patient quality of life. Therefore, the aim of this study was to assess the possible linkage between ABO blood groups and radiation-induced nausea and vomiting (RINV), also its incidence and affecting factors. One hundred twenty-eight patients referring to Tohid hospital of Sanandaj, Iran, were selected and the patients and treatment-related factors were determined in a cross-sectional study. Patients’ nausea and vomiting were recorded from the onset of treatment until 1 week after treatment accomplishment. Also, previous possible nausea and vomiting were recorded. The frequencies of nausea and vomiting and their peak time were examined during the treatment period. The association between ABO blood group and the incidence of radiotherapy-induced nausea and vomiting (RINV) were significant and it seems that A blood group patients are the most vulnerable individuals to these symptoms. The association between Rhesus antigen and the time of maximum severity of RINV may indicate that Rhesus antigen affects the time of maximum severity of RINV. The incidence of RINV was not affected by karnofsky performance status, but it was related to the severity of RINV. Furthermore, among the factors affecting the incidence of nausea and vomiting, nausea and vomiting during patient's previous chemotherapy, radiotherapy region, and background gastrointestinal disease were shown to be three important factors. In addition to familiar RINV-affecting factors, ABO blood group may play an important role and these results address the needs for further studies with larger sample size. PMID:27495037

  17. Radiation-induced degradation of DNA bases

    NASA Astrophysics Data System (ADS)

    Douki, T.; Delatour, T.; Martini, R.; Cadet, J.

    1999-01-01

    Radio-induced degradation of DNA involves radical processes. A series of lesions among the major bases degradation products has been measured in isolated DNA exposed to gamma radiation in aerated aqueous solution. Degradation can be accounted for by the formation of hydroxyl radicals upon radiolysis of water (indirect effect). The four bases are degraded in high yield. Direct effect has been mimicked by photo-induced electron abstraction from the bases producing their radical cation. Quantification of the modified bases showed that guanine is the preferential target. This can be explained by its lower oxidation potential and charge transfer phenomena. La décomposition radio-induite de l'ADN fait intervenir des processus radicalaires. Une série de lésions choisies parmi les produits majeurs de dégradation des bases a été mesurée dans de l'ADN isolé exposé au rayonnement en solution aqueuse aérée. Les modifications sont alors dues aux radicaux hydroxyles produits par la radiolyse de l'eau (effet indirect) et les quatre bases sont efficacement dégradées. L'arrachement d'électrons aux bases par photosensibilisation pour produire leur radical cation, a été utilisé comme modèle de l'effet direct. La quantification des bases modifiées montre que la guanine est préférentiellement dégradée. Cette observation peut s'expliquer par le plus faible potentiel d'oxydation de cette base ainsi que par les phénomènes de transfert de charge vers les guanines.

  18. Laser-induced reaction alumina coating on ceramic composite

    NASA Astrophysics Data System (ADS)

    Xiao, Chenghe

    Silicon carbide ceramics are susceptible to corrosion by certain industrial furnace environments. It is also true for a new class of silicon carbide-particulate reinforced alumina-matrix composite (SiCsb(P)Alsb2Osb3) since it contains more than 55% of SiC particulate within the composite. This behavior would limit the use of SiCsb(P)Alsb2Osb3 composites in ceramic heat exchangers. Because oxide ceramics corrode substantially less in the same environments, a laser-induced reaction alumina coating technique has been developed for improving corrosion resistance of the SiCsb(P)Alsb2Osb3 composite. Specimens with and without the laser-induced reaction alumina coating were subjected to corrosion testing at 1200sp°C in an air atmosphere containing Nasb2COsb3 for 50 ˜ 200 hours. Corroded specimens were characterized via x-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectrometer (EDS). The uncoated SiCsbP/Alsb2Osb3 composite samples experienced an initial increase in weight during the exposure to Nasb2COsb3 at 1200sp°C due to the oxidation of residual aluminum metal in the composite. There was no significant weight change difference experienced during exposure times between 50 and 200 hours. The oxidation layer formed on the as-received composite surface consisted of Si and Alsb2Osb3 (after washing with a HF solution). The oxidation layer grew outward and inward from the original surface of the composite. The growth rate in the outward direction was faster than in the inward direction. The formation of the Si/Alsb2Osb3 oxidation layer on the as-received composite was nonuniform, and localized corrosion was observed. The coated samples experienced very little mass increase. The laser-induced reaction alumina coating effectively provided protection for the SiCsbP/Alsb2Osb3 composite by keeping the corrodents from contacting the composite and by the formation of some refractory compounds such as Nasb2OAlsb2Osb3SiOsb2 and Nasb2Alsb{22}Osb

  19. Pravastatin limits radiation-induced vascular dysfunction in the skin.

    PubMed

    Holler, Valerie; Buard, Valerie; Gaugler, Marie-Helene; Guipaud, Olivier; Baudelin, Cedric; Sache, Amandine; Perez, Maria del R; Squiban, Claire; Tamarat, Radia; Milliat, Fabien; Benderitter, Marc

    2009-05-01

    About half of people with cancer are treated with radiation therapy; however, normal tissue toxicity still remains a dose-limiting factor for this treatment. The skin response to ionizing radiation may involve multiple inflammatory outbreaks. The endothelium is known to play a critical role in radiation-induced vascular injury. Furthermore, endothelial dysfunction reflects a decreased availability of nitric oxide. Statins have been reported to preserve endothelial function through their antioxidant and anti-inflammatory activities. In this study, wild type and endothelial nitric oxide synthase (eNOS)(-/-) mice were subjected to dorsal skin irradiation and treated with pravastatin for 28 days. We demonstrated that pravastatin has a therapeutic effect on skin lesions and abolishes radiation-induced vascular functional activation by decreasing interactions between leukocytes and endothelium. Pravastatin limits the radiation-induced increase of blood CCL2 and CXCL1 production expression of inflammatory adhesion molecules such as E-selectin and intercellular adhesion molecule-1, and inflammatory cell migration in tissues. Pravastatin limits the in vivo and in vitro radiation-induced downregulation of eNOS. Moreover, pravastatin has no effect in eNOS(-/-) mice, demonstrating that eNOS plays a key role in the beneficial effect of pravastatin in radiation-induced skin lesions. In conclusion, pravastatin may be a good therapeutic approach to prevent or reduce radiation-induced skin damage. PMID:19212344

  20. (Studies of heavy-ion induced reactions): Annual progress report

    SciTech Connect

    Mignerey, A.C.

    1986-10-01

    An experiment was performed at the Lawrence Berkeley Laboratory Bevalac, extending previous studies using inverse reactions to 50 MeV/u /sup 139/La incident on targets of C and Al. Studies of excitation energy division in lower energy division in lower energy heavy-ion reactions were furthered using kinematic coincidences to measure the excitation energies of primary products in the Fe + Ho reaction at 12 MeV/u. These results will provide important systematics for comparisons with previous measurements at 9 MeV/u on the same system and at 15 MeV/u on the Fe + Fe and Fe + U systems. Also studied were different aspects of 15 MeV/u Fe-induced reactions, with experiments performed at the Oak Ridge HHIRF. The first three contributions of this report constitute a major portion of the results from this research. Finally, at the Lawrence Berkeley Laboratory Bevalac a large detector array for coincident detection of fragmentation products in heavy-ion collisions below 100 MeV/u is being built. A list of publications, personnel, and activities is provided.

  1. Radiation-induced undifferentiated pleomorphic sarcoma after radiation therapy for a desmoid tumour.

    PubMed

    Di Marco, J; Kaci, R; Orcel, P; Nizard, R; Laredo, J-D

    2016-02-01

    Radiation-induced sarcoma is a long-term complication of radiation therapy. The most common secondary neoplasia is the undifferentiated pleomorphic sarcoma, which is usually described in the deep soft tissue of the trunk or extremities. Radiation-induced sarcomas have a poor prognosis. An early diagnosis and management are needed to improve the survival rate of such patients. We presently report a case of a radiation-induced undifferentiated pleomorphic sarcoma of the left gluteus maximus muscle, which developed 25 years after an initial diagnosis of aggressive fibromatosis and 21 years after a tumour recurrence. This case study illustrates the risk of developing a sarcoma in a radiation field and the need for long-term follow-up after radiation therapy. Unnecessary radiation therapy, in particular in the case of benign conditions in young patients, should be avoided. PMID:26725422

  2. Ionizing Radiation-Induced Endothelial Cell Senescence and Cardiovascular Diseases

    PubMed Central

    Wang, Yingying; Boerma, Marjan; Zhou, Daohong

    2016-01-01

    Exposure to ionizing radiation induces not only apoptosis but also senescence. While the role of endothelial cell apoptosis in mediating radiation-induced acute tissue injury has been extensively studied, little is known about the role of endothelial cell senescence in the pathogenesis of radiation-induced late effects. Senescent endothelial cells exhibit decreased production of nitric oxide and expression of thrombomodulin, increased expression of adhesion molecules, elevated production of reactive oxygen species and inflammatory cytokines and an inability to proliferate and form capillary-like structures in vitro. These findings suggest that endothelial cell senescence can lead to endothelial dysfunction by dysregulation of vasodilation and hemostasis, induction of oxidative stress and inflammation and inhibition of angiogenesis, which can potentially contribute to radiation-induced late effects such as cardiovascular diseases (CVDs). In this article, we discuss the mechanisms by which radiation induces endothelial cell senescence, the roles of endothelial cell senescence in radiation-induced CVDs and potential strategies to prevent, mitigate and treat radiation-induced CVDs by targeting senescent endothelial cells. PMID:27387862

  3. Ionizing Radiation-Induced Endothelial Cell Senescence and Cardiovascular Diseases.

    PubMed

    Wang, Yingying; Boerma, Marjan; Zhou, Daohong

    2016-08-01

    Exposure to ionizing radiation induces not only apoptosis but also senescence. While the role of endothelial cell apoptosis in mediating radiation-induced acute tissue injury has been extensively studied, little is known about the role of endothelial cell senescence in the pathogenesis of radiation-induced late effects. Senescent endothelial cells exhibit decreased production of nitric oxide and expression of thrombomodulin, increased expression of adhesion molecules, elevated production of reactive oxygen species and inflammatory cytokines and an inability to proliferate and form capillary-like structures in vitro. These findings suggest that endothelial cell senescence can lead to endothelial dysfunction by dysregulation of vasodilation and hemostasis, induction of oxidative stress and inflammation and inhibition of angiogenesis, which can potentially contribute to radiation-induced late effects such as cardiovascular diseases (CVDs). In this article, we discuss the mechanisms by which radiation induces endothelial cell senescence, the roles of endothelial cell senescence in radiation-induced CVDs and potential strategies to prevent, mitigate and treat radiation-induced CVDs by targeting senescent endothelial cells. PMID:27387862

  4. Radiation exposure induces inflammasome pathway activation in immune cells.

    PubMed

    Stoecklein, Veit M; Osuka, Akinori; Ishikawa, Shizu; Lederer, Madeline R; Wanke-Jellinek, Lorenz; Lederer, James A

    2015-02-01

    Radiation exposure induces cell and tissue damage, causing local and systemic inflammatory responses. Because the inflammasome pathway is triggered by cell death and danger-associated molecular patterns, we hypothesized that the inflammasome may signal acute and chronic immune responses to radiation. Using a mouse radiation model, we show that radiation induces a dose-dependent increase in inflammasome activation in macrophages, dendritic cells, NK cells, T cells, and B cells as judged by cleaved caspase-1 detection in cells. Time course analysis showed the appearance of cleaved caspase-1 in cells by day 1 and sustained expression until day 7 after radiation. Also, cells showing inflammasome activation coexpressed the cell surface apoptosis marker annexin V. The role of caspase-1 as a trigger for hematopoietic cell losses after radiation was studied in caspase-1(-/-) mice. We found less radiation-induced cell apoptosis and immune cell loss in caspase-1(-/-) mice than in control mice. Next, we tested whether uric acid might mediate inflammasome activation in cells by treating mice with allopurinol and discovered that allopurinol treatment completely blocked caspase-1 activation in cells. Finally, we demonstrate that radiation-induced caspase-1 activation occurs by a Nod-like receptor family protein 3-independent mechanism because radiation-exposed Nlrp3(-/-) mice showed caspase-1 activation profiles that were indistinguishable from those of wild-type mice. In summary, our data demonstrate that inflammasome activation occurs in many immune cell types following radiation exposure and that allopurinol prevented radiation-induced inflammasome activation. These results suggest that targeting the inflammasome may help control radiation-induced inflammation. PMID:25539818

  5. Two-photon-induced cycloreversion reaction of chalcone photodimers

    NASA Astrophysics Data System (ADS)

    Träger, J.; Härtner, S.; Heinzer, J.; Kim, H.-C.; Hampp, N.

    2008-04-01

    The photocleavage reaction of chalcone photodimers has been studied using a two-photon process. For this purpose, a novel chalcone dimer has been synthesized as a low molecular weight model substance for polymer bound chalcones and its photochemistry triggered by two-photon-absorption (2PA) has been investigated using a pulsed frequency-doubled Nd:YAG-laser. The 2PA-induced cycloreversion reaction selectively leads to the cleavage of the chalcone photodimers resulting in the formation of monomeric chalcone molecules. Hence, as an application chalcones can be used as a photosensitive linker which can be cleaved beyond an UV-absorbing barrier. The 2PA cross section of the chalcone photodimer was determined to be of 1.1 × 10 -49 cm 4 s photon -1 (11 GM).

  6. Granulomatous tattoo reaction induced by intense pulse light treatment.

    PubMed

    Tourlaki, Athanasia; Boneschi, Vinicio; Tosi, Diego; Pigatto, Paolo; Brambilla, Lucia

    2010-10-01

    Cosmetic tattooing involves implantation of pigments into the dermis in order to create a permanent makeup. Here, we report a case of sarcoidal granulomatous reaction to old cosmetic tattoos after an intense pulsed light (IPL) treatment for facial skin rejuvenation. We consider this case as a peculiar example of photo-induced reaction to tattoo. In addition, we hypothesize that an underlying immune dysfunction was present, and acted as a predisposing factor for this unusual response, as the patient had suffered from an episode of acute pulmonary sarcoidosis 15 years before. Overall, our observation suggests that IPL treatment should be used cautiously in patients with tattoos, especially when a history of autoimmune disease is present. PMID:21175859

  7. Establishing a theory for deuteron induced surrogate reactions

    SciTech Connect

    Potel, G; Nunes, F M; Thompson, I J

    2015-09-18

    Background: Deuteron-induced reactions serve as surrogates for neutron capture into compound states. Although these reactions are of great applicability, no theoretical efforts have been invested in this direction over the last decade. Purpose: The goal of this work is to establish on firm grounds a theory for deuteron-induced neutron-capture reactions. This includes formulating elastic and inelastic breakup in a consistent manner. Method: We describe this process both in post- and prior-form distorted wave Born approximation following previous works and discuss the differences in the formulation. While the convergence issues arising in the post formulation can be overcome in the prior formulation, in this case one still needs to take into account additional terms due to nonorthogonality. Results: We apply our method to the Nb93(d,p)X at Ed=15 and 25 MeV and are able to obtain a good description of the data. We then look at the various partial wave contributions, as well as elastic versus inelastic contributions. We also connect our formulation with transfer to neutron bound states.Conclusions: Our calculations demonstrate that the nonorthogonality term arising in the prior formulation is significant and is at the heart of the long-standing controversy between the post and the prior formulations of the theory. We also show that the cross sections for these reactions are angular-momentum dependent and therefore the commonly used Weisskopf limit is inadequate. We finally make important predictions for the relative contributions of elastic breakup and nonelastic breakup and call for elastic-breakup measurements to further constrain our model.

  8. Establishing a theory for deuteron induced surrogate reactions

    DOE PAGESBeta

    Potel, G; Nunes, F M; Thompson, I J

    2015-09-18

    Background: Deuteron-induced reactions serve as surrogates for neutron capture into compound states. Although these reactions are of great applicability, no theoretical efforts have been invested in this direction over the last decade. Purpose: The goal of this work is to establish on firm grounds a theory for deuteron-induced neutron-capture reactions. This includes formulating elastic and inelastic breakup in a consistent manner. Method: We describe this process both in post- and prior-form distorted wave Born approximation following previous works and discuss the differences in the formulation. While the convergence issues arising in the post formulation can be overcome in the priormore » formulation, in this case one still needs to take into account additional terms due to nonorthogonality. Results: We apply our method to the Nb93(d,p)X at Ed=15 and 25 MeV and are able to obtain a good description of the data. We then look at the various partial wave contributions, as well as elastic versus inelastic contributions. We also connect our formulation with transfer to neutron bound states.Conclusions: Our calculations demonstrate that the nonorthogonality term arising in the prior formulation is significant and is at the heart of the long-standing controversy between the post and the prior formulations of the theory. We also show that the cross sections for these reactions are angular-momentum dependent and therefore the commonly used Weisskopf limit is inadequate. We finally make important predictions for the relative contributions of elastic breakup and nonelastic breakup and call for elastic-breakup measurements to further constrain our model.« less

  9. Establishing a theory for deuteron-induced surrogate reactions

    NASA Astrophysics Data System (ADS)

    Potel, G.; Nunes, F. M.; Thompson, I. J.

    2015-09-01

    Background: Deuteron-induced reactions serve as surrogates for neutron capture into compound states. Although these reactions are of great applicability, no theoretical efforts have been invested in this direction over the last decade. Purpose: The goal of this work is to establish on firm grounds a theory for deuteron-induced neutron-capture reactions. This includes formulating elastic and inelastic breakup in a consistent manner. Method: We describe this process both in post- and prior-form distorted wave Born approximation following previous works and discuss the differences in the formulation. While the convergence issues arising in the post formulation can be overcome in the prior formulation, in this case one still needs to take into account additional terms due to nonorthogonality. Results: We apply our method to the 93Nb(d ,p )X at Ed=15 and 25 MeV and are able to obtain a good description of the data. We look at the various partial wave contributions, as well as elastic versus inelastic contributions. We also connect our formulation with transfer to neutron bound states. Conclusions: Our calculations demonstrate that the nonorthogonality term arising in the prior formulation is significant and is at the heart of the long-standing controversy between the post and the prior formulations of the theory. We also show that the cross sections for these reactions are angular-momentum dependent and therefore the commonly used Weisskopf limit is inadequate. Finally, we make important predictions for the relative contributions of elastic breakup and nonelastic breakup and call for elastic-breakup measurements to further constrain our model.

  10. Electronically induced surface reactions: Evolution, concepts, and perspectives

    SciTech Connect

    Menzel, Dietrich

    2012-09-07

    This is a personal account of the development of the title subject which is the broader field encompassing surface photochemistry. It describes the early times when the main interest centered on desorption induced by slow electrons, follows its evolution in experiment (use of synchrotron radiation and connections to electron spectroscopies; use of lasers) and mechanisms, and briefly mentions the many different subfields that have evolved. It discusses some practically important aspects and applications and ends with an account of an evolving new subfield, the application to photochemistry on nanoparticles.

  11. Reaction mechanism studies of heavy ion induced nuclear reactions. Annual progress report

    SciTech Connect

    Mignerey, A.C.

    1981-07-01

    The research summarized in this report was performed during the period August 1, 1980 to June 30, 1981. The experimental emphasis in the heavy-ion-induced reaction studies continues to be discrete charge and mass resolution of all projectile-like fragments measured. In an experiment performed at the Argonne National Laboratory Superconducting LINAC, the /sup 37/Cl beam was used to bombard targets of /sup 40/Ca and /sup 209/Bi. This experiment is compared to results of our previous /sup 56/Fe-induced experiments. Attempts were made to extend the /sup 56/Fe reactions to lower energies at the Lawrence Berkeley Laboratory SuperHILAC. In a desire to improve the mass and charge resolution of previous experiments we tried a time-of-flight telescope employing both a channel-plate start and stop signal. This was backed by an ion chamber ..delta..E and silicon E detector. The operational difficulties encountered are being corrected and we hope to have a reliable system ready this fall. Studies of target fragmentation in /sup 4/He-induced reactions are continuing via experiments and model calculations. The program which began at the University of Maryland Cyclotron has been continued at the Indiana University Cyclotron with 120 and 200 MeV /sup 4/He incident on /sup 12/C and /sup 27/Al targets. While the Indiana data are currently being analyzed and no results are yet available, a summary of the Maryland work is given. Also presented in this section are the model calculations used to describe the data. 28 refs.

  12. Spin Modes, Neutrino-Induced Reactions and Nucleosynthesis in Stars

    SciTech Connect

    Suzuki, Toshio; Otsuka, Takaharu; Honma, Michio; Higashiyama, Koji

    2008-11-11

    Recent advances in shell model calculations of spin modes in nuclei with the use of new shell model Hamiltonians are discussed. Important roles of tensor interaction in shell evolutions toward drip-lines are pointed out. Electromagnetic transitions in exotic carbon isotopes are investigated. Anomalous supressions of transition strengths in the isotopes are found to be rather well explained. Neutrino-induced reactions on {sup 56}Fe and {sup 56}Ni are studied, and implications on production yields of heavy elements in stars are discussed.

  13. Nuclear reactions induced by. pi. /sup -/ at rest

    SciTech Connect

    Gadioli, E.; Gadioli Erba, E.

    1987-08-01

    The experimental information on reactions induced by stopped ..pi../sup -/ absorbed in nuclei is critically reviewed. Evidence for the presence of ..cap alpha..-cluster absorptions is presented and arguments are given to show that approx. =25% of ..pi../sup -/ absorptions are of this kind. In the case of two-nucleon absorption, the existing experimental information concerning the ratio of n-p to p-p absorbing pairs is discussed. Calculations of particle spectra and residue spallation yield distributions that, in addition to two-nucleon absorption, include ..cap alpha..-cluster absorption are presented, and it is shown that a satisfactory reproduction of the data is achieved.

  14. Shock induced chemical reactions in energetic structural materials

    NASA Astrophysics Data System (ADS)

    Reding, Derek J.

    Energetic structural materials (ESMs) constitute a new class of materials that provide dual functions of strength and energetic characteristics. ESMs are typically composed of micron-scale or nano-scale intermetallic mixtures or mixtures of metals and metal oxides, polymer binders, and structural reinforcements. Voids are included to produce a composite with favorable chemical reaction characteristics. In this thesis, a continuum approach is used to simulate gas-gun or explosive loading experiments where a strong shock is induced in the ESM by an impacting plate. Algorithms are developed to obtain equations of state of mixtures. It is usually assumed that the shock loading increases the energy of the ESM and causes the ESM to reach the transition state. It is also assumed that the activation energy needed to reach the transition state is a function of the temperature of the mixture. In this thesis, it is proposed that the activation energy is a function of temperature and the stress state of the mixture. The incorporation of such an activation energy is selected in this thesis. Then, a multi-scale chemical reaction model for a heterogeneous mixture is introduced. This model incorporates reaction initiation, propagation, and extent of completed reaction in spatially heterogeneous distributions of reactants. A new model is proposed for the pore collapse of mixtures. This model is formulated by modifying the Carol, Holt, and Nesterenko spherically symmetric model to include mixtures and compressibility effects. Uncertainties in the model result from assumptions in formulating the models for continuum relationships and chemical reactions in mixtures that are distributed heterogeneously in space and in numerical integration of the resulting equations. It is important to quantify these uncertainties. In this thesis, such an uncertainty quantification is investigated by systematically identifying the physical processes that occur during shock compression of ESMs which are

  15. Nucleation and reaction rates controlled by local reaction volume and reaction-induced stress - spinel layer growth as an example

    NASA Astrophysics Data System (ADS)

    Götze, Lutz C.; Milke, Ralf; Dohmen, Ralf; Wirth, Richard

    2014-05-01

    %) and a positive volume change at the Sp-Cor interface (by +17 %). We observed in TEM images formation of porosity at the Sp-Per substrate interface and lattice strain in the polycrystalline corundum substrate at the Sp-Cor substrate interface, both observations being fully in line with the respective local volume changes. We infer that the local stress field between the growing reaction layer and the rigid single crystal substrate is responsible for the dramatic effect on both the nucleation and reaction rates. With respect to minerals growing at dry conditions in the Earth's crust (granulite facies) we infer that rates of reactions might strongly depend on local volume changes at interfaces, that reactions are impeded by compressive reaction-induced stress applied to rigid neighboring grains, and that nucleation of thermodynamically stable phases on grain boundaries might be suppressed by a positive reaction volume.

  16. Infrared Laser Generation Of Heterogeneous Catalysts And Laser-Induced Reactions At Catalytic Surfaces

    NASA Astrophysics Data System (ADS)

    Danen, Wayne C.; Cheng, , Sheng-San; Iyer, Pradeep K.; Chiou, Shane-Jaw

    1984-05-01

    It has been demonstrated that continuous wave infrared CO2 laser radiation can be util-ized to rapidly produce active catalysts from inert precursors. The activity and selectiv-ity of Ca0 produced from Ca(OH)2 for the isomerization of 1-butene to cis- and trans-2-but-ene is discussed. Variation of the laser irradiation time produces catalytic activity and selectivity qualitatively similar to that resulting from conventional calcination at different temperatures. Pulsed infrared laser-induced reactions at catalytic surfaces are also discussed with emphasis on the dehydrobromination of 2-bromopropane and ethylene elimination from glycine ethyl ester hydrochloride at BaSO4 , A1PO4, and similar surfaces. Correlations are made of the extent of reaction with various experimental parameters including nature of the catalyst, laser frequency, laser fluence, number of laser pulses, and reagent-catalyst ratio.

  17. Clinical and dosimetric factors of radiation-induced esophageal injury: Radiation-induced esophageal toxicity

    PubMed Central

    Qiao, Wen-Bo; Zhao, Yan-Hui; Zhao, Yan-Bin; Wang, Rui-Zhi

    2005-01-01

    AIM: To analyze the clinical and dosimetric predictive factors for radiation-induced esophageal injury in patients with non-small-cell lung cancer (NSCLC) during three-dimensional conformal radiotherapy (3D-CRT). METHODS: We retrospectively analyzed 208 consecutive patients (146 men and 62 women) with NSCLC treated with 3D-CRT. The median age of the patients was 64 years (range 35-87 years). The clinical and treatment parameters including gender, age, performance status, sequential chemotherapy, concurrent chemotherapy, presence of carinal or subcarinal lymph nodes, pretreatment weight loss, mean dose to the entire esophagus, maximal point dose to the esophagus, and percentage of volume of esophagus receiving >55 Gy were studied. Clinical and dosimetric factors for radiation-induced acute and late grade 3-5 esophageal injury were analyzed according to Radiation Therapy Oncology Group (RTOG) criteria. RESULTS: Twenty-five (12%) of the two hundred and eight patients developed acute or late grade 3-5 esophageal injury. Among them, nine patients had both acute and late grade 3-5 esophageal injury, two died of late esophageal perforation. Concurrent chemotherapy and maximal point dose to the esophagus ≥60 Gy were significantly associated with the risk of grade 3-5 esophageal injury. Fifty-four (26%) of the two hundred and eight patients received concurrent chemotherapy. Among them, 25 (46%) developed grade 3-5 esophageal injury (P = 0.0001<0.01). However, no grade 3-5 esophageal injury occurred in patients who received a maximal point dose to the esophagus <60 Gy (P = 0.0001<0.01). CONCLUSION: Concurrent chemotherapy and the maximal esophageal point dose ≥60 Gy are significantly associated with the risk of grade 3-5 esophageal injury in patients with NSCLC treated with 3D-CRT. PMID:15849822

  18. Mass and charge distributions in Fe-induced reactions

    SciTech Connect

    Madani, H.; Mignerey, A.C.; Marchetti, A.A.; Weston-Dawkes, A.P.; Kehoe, W.L.; Obenshain, F.

    1995-02-21

    The charge and mass of the projectile-like fragments produced in the 12-MeV/nucleon {sup 56}Fe + {sup 165}Ho reaction were measured at a laboratory scattering angle of 16 degrees. The mass and charge distributions of the projectile-like fragments were generated as a function of total kinetic energy loss (TKEL), and characterized by their neutron and proton centroids and variances, and correlation factors. A weak drift of the system towards mass asymmetry, opposite to the direction which minimizes the potential energy of the composite system, was observed. The increase in the variances with energy loss is consistent with a nucleon exchange mechanism as a means for energy dissipation. Predictions of two nucleon exchange models, Randrup`s and, Tassan-Got`s models, are compared to the experimental results of the 672-MeV {sup 56}Fe + {sup 165}Ho reaction and to other Fe-induced reactions. The proton and neutron centroids were found to be generally better reproduced by Tassan-Got`s model than by Randrup`s model. The variances and correlation factor are well reproduced for asymmetric systems by both models.

  19. Effects of solar radiation on manganese oxide reactions with selected organic compounds

    SciTech Connect

    Bertino, D.J.; Zepp, R.G. )

    1991-07-01

    The effects of sunlight on aqueous redox reactions between manganese oxides (MnO{sub x}) and selected organic substances are reported. No sunlight-induced rate enhancement was observed for the MnO{sub x} oxidation of substituted phenols, anisole, o-dichlorobenzene, or p-chloroaniline. On the other hand, solar radiation did accelerate the reduction of manganese oxides by dissolved organic matter (DOM) from aquatic environments. The photoreduction of MnO{sub x} by DOM was little affected by molecular oxygen in air-saturated water (250 {mu}M), but was inhibited by 2,6-dichloroindophenol (0.5-6 {mu}M), and excellent electron acceptor. MnO{sub x} reduction also was photosensitized by anthraquinone-2-sulfonate. These results indicate that the photoreduction probably involves electron transfer from excited states of sorbed DOM to the oxide surface. Wavelength studies indicated that ultraviolet-B radiation (280-320 nm) plays an important role in this photoreduction.

  20. Radiation-induced charge trapping in bipolar base oxides

    SciTech Connect

    Fleetwood, D.M.; Riewe, L.C.; Witczak, Schrimpf, R.D.

    1996-03-01

    Capacitance-voltage and thermally stimulated current methods are used to investigate radiation induced charge trapping in bipolar base oxides. Results are compared with models of oxide and interface trap charge buildup at low electric fields.

  1. Radiation-induced impairment of neuronal excitability

    SciTech Connect

    Pellmar, T.C.; Tolliver, J.M.; Neel, K.L.

    1988-01-01

    Radiation causes a decrease in the synaptically evoked activity of CA1 hippocampal pyramidal cells. This effect is dose and dose-rate dependent. Hydrogen peroxide, which produces hydroxyl free radicals when combined with FE + 2, produces similar damage. In contrast, the radioprotectant, dithiothreitol, increases the excitability of hippocampal neurons. These studies indicate that radiation can directly affect the function of central neurons.

  2. 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.

  3. Effect of radiation-induced damage on deuterium retention in tungsten, tungsten coatings and Eurofer

    NASA Astrophysics Data System (ADS)

    Ogorodnikova, O. V.; Sugiyama, K.

    2013-11-01

    An influence of radiation-induced damage on hydrogen isotope retention and transport in a bulk tungsten (W), dense nano-structured W coatings and Eurofer was investigated under well-defined laboratory conditions. Radiation-induced defects in W materials and Eurofer were created by irradiation with 20 MeV W ions. Following the damage production, samples were exposed to low-energy deuterium plasma. The deuterium (D) retention in each sample was subsequently measured by nuclear reaction analysis (NRA) for the depth profiling up to 6 μm. It was shown that the D retention at radiation-induced damage is almost equivalent for different W grades after irradiation at high enough fluence. The kinetic of D migration and trapping in damaged area as well as recovery of radiation-induced damage were investigated by loading at different temperatures. It was shown that deuterium retention in tungsten in fusion environment will be dominated by radiation-induced effect in a wide range of investigated temperatures, namely, from room temperature to 1100 K. Whereas displacement damage produced in Eurofer has less pronounced effect on the deuterium accumulation.

  4. Coherent microwave radiation from a laser induced plasma

    SciTech Connect

    Shneider, M. N.; Miles, R. B.

    2012-12-24

    We propose a method for generation of coherent monochromatic microwave/terahertz radiation from a laser-induced plasma. It is shown that small-scale plasma, located in the interaction region of two co-propagating plane-polarized laser beams, can be a source of the dipole radiation at a frequency equal to the difference between the frequencies of the lasers. This radiation is coherent and appears as a result of the so-called optical mixing in plasma.

  5. The issue of 'molecular radiators' in microwave-assisted reactions. Computational calculations on ring closing metathesis (RCM).

    PubMed

    Rodríguez, A M; Prieto, P; de la Hoz, A; Díaz-Ortiz, A; García, J I

    2014-04-21

    A DFT computational mechanistic study of the ring closing metathesis (RCM) reaction of diallyl ether or N,N-diallyl-p-toluenesulfonamide catalyzed by a second generation Grubbs-type ruthenium carbene complex has been carried out. This study was performed at the PCM(CH2Cl2)-B3LYP/6-311+G(2d,p)//B3LYP/SDD theory level. The aim of this work was to shed light on the influence that microwave irradiation has on these reactions and to gain insight into the so-called 'molecular radiator' effect. The outcomes obtained indicate that thermal effects induced by microwave irradiation decrease the catalytic induction period. The presence of a polar reagent and/or polar species in the reaction that increases the polarity of the medium may enhance this thermal effect. PMID:24599220

  6. 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

  7. Particle beams in ultrastrong laser fields: direct laser acceleration and radiation reaction effects

    NASA Astrophysics Data System (ADS)

    Salamin, Yousef I.; Li, Jian-Xing; Hatsagortsyan, Karen Z.; Tamburini, Matteo; Di Piazza, Antonino; Keitel, Christoph H.

    2015-03-01

    Several aspects of the interaction of particle beams with ultrastrong laser fields are discussed. Firstly, we consider regimes when radiation reaction is not essential and it is demonstrated that employing chirped laser pulses, significant improvement of the direct acceleration of particles can be achieved. Results from single- and many-particle calculations of the particle acceleration, in vacuum, by plane-wave fields, as well as in tightly-focused laser beams, show that the mean energies and their spreads qualify them for important applications. Secondly, we investigate the effect of radiation reaction in electron-laser-beam interactions. Signatures of the quantum radiation reaction during the interaction of an electron bunch with a focused superstrong ultrashort laser pulse can be observed in a characteristic behavior of the spectral bandwidth, and the angular spread of the nonlinear Compton radiation on the laser pulse duration. Furthermore, it is shown that the radiation reaction effects can be employed to control the electron dynamics via the nonlinear interplay between the Lorentz and radiation reaction forces. In particular, it is shown that an ultrarelativistic electron bunch colliding head- on with a strong bichromatic laser pulse can be deflected in a controllable way, by changing either the relative phase or the relative amplitude between the two frequency components of the bichromatic field.

  8. Step-by-Step Simulation of Radiation of Radiation Chemistry Using Green Functions for Diffusion-Influenced Reactions

    NASA Technical Reports Server (NTRS)

    Plante, Ianik; Cucinotta, Francis A.

    2011-01-01

    The irradiation of biological systems leads to the formation of radiolytic species such as H(raised dot), (raised dot)OH, H2, H2O2, e(sup -)(sub aq), etc.[1]. These species react with neighboring molecules, which result in damage in biological molecules such as DNA. Radiation chemistry is there for every important to understand the radiobiological consequences of radiation[2]. In this work, we discuss an approach based on the exact Green Functions for diffusion-influenced reactions which may be used to simulate radiation chemistry and eventually extended to study more complex systems, including DNA.

  9. Energy conservation equation for a radiating pointlike charge in the context of the Abraham-Lorentz versus the Abraham-Becker radiation-reaction force

    NASA Astrophysics Data System (ADS)

    Bellotti, U.; Bornatici, M.

    1997-12-01

    With reference to a radiating pointlike charge, the energy conservation equation comprising the effect of the Abraham-Lorentz radiation-reaction force is contrasted with the incorrect energy conservation equation obtained by Hartemann and Luhmann [Phys. Rev. Lett. 74, 1107 (1995)] on considering instead the Abraham-Becker force that accounts only for a part of the instantaneous radiation-reaction force.

  10. Clinical Features of Oxaliplatin Induced Hypersensitivity Reactions and Therapeutic Approaches.

    PubMed

    Bano, Nusrat; Najam, Rahila; Qazi, Faaiza; Mateen, Ahmed

    2016-01-01

    Oxaliplatin, a third generation novel platinum compound is the most effective first line chemotherapeutic agent for colorectal cancer (CRC) in combination with 5FU and leucovorin. It is indicated for pancreatic, gastric and testicular cancers combined with bevacuzimab, capecitabine, irinotecan and other cytotoxic agents. However, moderate to severe hypersensitivity reactions (HSR) during or after oxaliplatin infusion usually require cessation of chemotherapy or substitution of the key therapeutic drug which largely interferes with improved patient prognosis. This mini- review showcases recent and accepted opinions/approaches in oxaliplatin induced HSR management. Physicians and oncologists have varying attitudes regarding the decision to rechallenge the patient after an HSR experience, efficacy of desensitization protocols, effectiveness and selection of drugs for premedication and possibilities of cross sensitivity to other platinum agents (e.g. carboplatin). A brief insight into underlying molecular mechanisms and clinical manifestations of oxaliplatin induced HSR is offered. We have also discussed the management of oxaliplatin induced HSR and risk stratification for a successful and complete chemotherapeutic plan. PMID:27221832

  11. Characterization of radiation-induced Apoptosis in rodent cell lines

    SciTech Connect

    Guo, Min; Chen, Changhu; Ling, C.C.

    1997-03-01

    For REC:myc(ch1), Rat1 and Rat1:myc{sub b} cells, we determined the events in the development of radiation-induced apoptosis to be in the following order: cell division followed by chromatin condensation, membrane blebbing, loss of adhesion and the uptake of vital dye. Experimental data which were obtained using {sup 4}He ions of well defined energies and which compared the dependence of apoptosis and clonogenic survival on {sup 4}He range strongly suggested that in our cells both apoptosis and loss of clonogenic survival resulted from radiation damage to the cell nucleus. Corroboratory evidence was that BrdU incorporation sensitized these cells to radiation-induced apoptosis. Comparing the dose response for apoptosis and the clonogenic survival curves for Rat1 and Rat1:myc{sub b} cells, we concluded that radiation-induced cell inactivation as assayed by clonogenic survival, and that a modified linear-quadratic model, proposed previously, modeled such a contribution effectively. In the same context, the selective increase in radiation-induced apoptosis. Comparing the dose response for apoptosis and the clonogenic survival curves for Rat1 and Rat1:myc{sub b} cells, we concluded that radiation-induced apoptosis contributed to the overall radiation-induced cell inactivation as assayed by clonogenic survival, and that a modified linear-quadratic model, proposed previously, modeled such a contribution effectively. In the same context, the selective increase in radiation-induced apoptosis during late S and G{sub 2} phases reduced the relative radioresistance observed for clonogenic survival during late S and G{sub 2} phases. 30 refs., 8 figs.

  12. Hedgehog signaling and radiation induced liver injury: a delicate balance

    PubMed Central

    Kabarriti, Rafi

    2016-01-01

    Radiation-induced liver disease (RILD) is a major limitation of radiation therapy (RT) for the treatment of liver cancer. Emerging data indicate that hedgehog (Hh) signaling plays a central role in liver fibrosis and regeneration after liver injury. Here, we review the potential role of Hh signaling in RILD and propose the temporary use of Hh inhibition during liver RT to radiosensitize HCC tumor cells and inhibit their progression, while blocking the initiation of the radiation-induced fibrotic response in the surrounding normal liver. PMID:26202634

  13. Hyperbaric oxygen: Primary treatment of radiation-induced hemorrhagic cystitis

    SciTech Connect

    Weiss, J.P.; Neville, E.C.

    1989-07-01

    Of 8 patients with symptoms of advanced cystitis due to pelvic radiation treated with hyperbaric oxygen 7 are persistently improved during followup. All 6 patients treated for gross hematuria requiring hospitalization have been free of symptoms for an average of 24 months (range 6 to 43 months). One patient treated for stress incontinence currently is dry despite little change in bladder capacity, implying salutary effect from hyperbaric oxygen on the sphincter mechanism. One patient with radiation-induced prostatitis failed to respond. This experience suggests that hyperbaric oxygen should be considered the primary treatment for patients with symptomatic radiation-induced hemorrhagic cystitis.

  14. Hedgehog signaling and radiation induced liver injury: a delicate balance.

    PubMed

    Kabarriti, Rafi; Guha, Chandan

    2014-07-01

    Radiation-induced liver disease (RILD) is a major limitation of radiation therapy (RT) for the treatment of liver cancer. Emerging data indicate that hedgehog (Hh) signaling plays a central role in liver fibrosis and regeneration after liver injury. Here, we review the potential role of Hh signaling in RILD and propose the temporary use of Hh inhibition during liver RT to radiosensitize HCC tumor cells and inhibit their progression, while blocking the initiation of the radiation-induced fibrotic response in the surrounding normal liver. PMID:26202634

  15. Radiation reaction and pitch-angle changes for a charge undergoing synchrotron losses

    NASA Astrophysics Data System (ADS)

    Singal, Ashok K.

    2016-05-01

    In the derivation of synchrotron radiation formulae, it has been assumed that the pitch angle of a charge remains constant during the radiation process. However, from the radiation reaction formula, while the component of the velocity vector perpendicular to the magnetic field reduces in magnitude due to radiative losses, the parallel component does not undergo any change during radiation. Therefore, there is a change in the ratio of the two components, implying a change in the pitch angle. We derive the exact formula for the change in energy of radiating electrons by taking into account the change of the pitch angle due to radiative losses. From this, we derive the characteristic decay time of synchrotron electrons over which they turn from highly relativistic into mildly relativistic ones.

  16. Structure effects on reaction mechanisms in collisions induced by radioactive ion beams

    SciTech Connect

    Pietro, A. Di Figuera, P.; Scuderi, V.; Amorini, F.; Angulo, C.; Cardella, G.; Casarejos, E.; Cherubini, S.; Lu, J.; Marchetta, C.; Musumarra, A.; Papa, M.; Pellegriti, M.; Pizzone, R. G.; Raabe, R.; Rizzo, F.; Sida, J. L.; Tian, W.

    2006-08-15

    The present paper concerns the study of reactions induced by radioactive beams of halo and weakly bound nuclei at energies around and above the Coulomb barrier. The results obtained for the reaction induced by the halo nucleus {sup 6}He on {sup 64}Zn have been compared with the results for the reaction induced by {sup 4}He on the same target. The results of the reaction induced by the weakly bound unstable {sup 13}N on the weakly bound {sup 9}Be have been compared with those for the reaction {sup 10}B + {sup 12}C.

  17. A Transport Model for Nuclear Reactions Induced by Radioactive Beams

    SciTech Connect

    Li Baoan; Chen Liewen; Das, Champak B.; Das Gupta, Subal; Gale, Charles; Ko, C.M.; Yong, G.-C.; Zuo Wei

    2005-10-14

    Major ingredients of an isospin and momentum dependent transport model for nuclear reactions induced by radioactive beams are outlined. Within the IBUU04 version of this model we study several experimental probes of the equation of state of neutron-rich matter, especially the density dependence of the nuclear symmetry energy. Comparing with the recent experimental data from NSCL/MSU on isospin diffusion, we found a nuclear symmetry energy of Esym({rho}) {approx_equal} 31.6({rho}/{rho}0)1.05 at subnormal densities. Predictions on several observables sensitive to the density dependence of the symmetry energy at supranormal densities accessible at GSI and the planned Rare Isotope Accelerator (RIA) are also made.

  18. Laser induced sonofusion: A new road toward thermonuclear reactions

    NASA Astrophysics Data System (ADS)

    Sadighi-Bonabi, Rasoul; Gheshlaghi, Maryam

    2016-03-01

    The Possibility of the laser assisted sonofusion is studied via single bubble sonoluminescence (SBSL) in Deuterated acetone (C3D6O) using quasi-adiabatic and hydro-chemical simulations at the ambient temperatures of 0 and -28.5 °C. The interior temperature of the produced bubbles in Deuterated acetone is 1.6 × 106 K in hydro-chemical model and it is reached up to 1.9 × 106 K in the laser induced SBSL bubbles. Under these circumstances, temperature up to 107 K can be produced in the center of the bubble in which the thermonuclear D-D fusion reactions are promising under the controlled conditions.

  19. 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.

  20. Radiation induced destruction of thebaine, papaverine and noscapine in methanol

    NASA Astrophysics Data System (ADS)

    Kantoğlu, Ömer; Ergun, Ece

    2016-07-01

    The presence of methanol decreases the efficiency of radiation-induced decomposition of alkaloids in wastewater. Intermediate products were observed before the complete degradation of irradiated alkaloids. In order to identify the structure of the by-products and the formation pathway, thebaine, papaverine and noscapine solutions were prepared in pure methanol and irradiated using a 60Co gamma cell at absorbed doses of 0, 1, 3, 5, 7, 10, 30, 50 and 80 kGy. The dose-dependent alkaloid degradation and by-product formation were monitored by ESI mass spectrometer. Molecular structures of the by-products and reaction pathways were proposed. Oxygenated and methoxy group containing organic compounds was observed in the mass spectra of irradiated alkaloids. At initial dose values oxygenated by-products were formed due to the presence of dissolved oxygen in solutions. After the consumption of dissolved oxygen with radicals, the main mechanism was addition of solvent radicals to alkaloid structure. However, it was determined that alkaloids and by-products were completely degraded at doses higher than 50 kGy. The G-value and degradation efficiency of alkaloids were also evaluated.

  1. Modeling chemical reactions in laser-induced plasmas

    NASA Astrophysics Data System (ADS)

    Shabanov, S. V.; Gornushkin, I. B.

    2015-11-01

    Under the assumption of local thermal equilibrium, a numerical algorithm is proposed to find the equation of state for laser-induced plasmas (LIPs) in which chemical reactions are permitted in addition to ionization processes. The Coulomb interaction in plasma is accounted for by the Debye-Hückel method. The algorithm is used to calculate the equation of state for LIPs containing carbon, silicon, nitrogen, and argon. The equilibrium reaction constants are calculated using the latest experimental and ab initio data of spectroscopic constants for the molecules {N}_2, {C}_2, {Si}_2, {CN}, {SiN}, {SiC} and their ions. The algorithm is incorporated into a fluid dynamic numerical model based on the Navier-Stokes equations describing an expansion of LIP plumes into an ambient gas. The dynamics of LIP plumes obtained by the ablation of SiC, solid silicon, or solid carbon in an ambient gas containing {N}_2 and Ar is simulated to study formation of molecules and molecular ions.

  2. Reaction-induced strain localization: Torsion experiments on dolomite

    NASA Astrophysics Data System (ADS)

    Delle Piane, Claudio; Burlini, Luigi; Grobety, Bernard

    2007-04-01

    We investigated the mechanical behaviour and microstructural evolution of a dolomite marble from Mt. Frerone (Adamello, N-Italy) during decarbonation to calcite and periclase in torsion experiments. Tests were performed in a Paterson gas-medium apparatus on cylindrical samples of 10 mm diameter and 10 mm length. Experiments were conducted at 800 °C, 300 MPa confining pressure under both vented and non-vented conditions, up to a maximum bulk shear strain of about γ = 1.8, at different strain rates (3 × 10 - 5 s - 1 up to 3 × 10 - 4 s - 1 ). Under hydrostatic conditions the nominal equilibrium P(CO 2) should be around 100 MPa, but in the vented experiments the CO 2 was free to escape, causing the breakdown of dolomite. During the decomposition, deformation was systematically localized at the ends of the specimens, near the porous spacers into a fine-grained mixture of calcite and periclase. Due to the low permeability of the marble, pore fluid could not escape from the central part of the sample building up CO 2 pressure which suppressed the decarbonation reaction. The fluid pressure embrittled the material and caused the development of en-echelon tension fractures, inclined opposite to the sense of shear. We conclude that decarbonation produced a weak polyphase matrix composed of submicron sized reaction products. Such a small grain size induced strain localization which was probably promoted by a switch from grain-size insensitive to grain-size sensitive deformation mechanism.

  3. Electro-induced manipulations of liquid marbles for chemical reactions

    NASA Astrophysics Data System (ADS)

    Liu, Zhou; Fu, Xiangyu; Binks, Bernard P.; Shum, Ho Cheung; Microfluidics; Soft Matter Group in University of Hong Kong Team; Surfactant; Colloid Group at Hull Team

    2015-11-01

    Liquid marbles, liquid droplets coated by non-wetting particles, have been well demonstrated as a promising template for various droplet-based applications, in particular for chemical reactions. In these applications, controlled manipulations on liquid marbles, including coalescence and mixing, are highly demanded but yet rarely investigated. In this work, we study the coalescence and mixing of liquid marbles controlled by an electric field. We found that a sufficiently large applied voltage can cause the coalescence of two or multiple marbles arranged in a chain. This critical voltage, leading to the consequent coalescence, increases with the number of the liquid marbles. In addition, the imposed electric stress can induce convective liquid flow within the different liquid marbles, resulting in rapid and efficient mixing. The mixing efficiency can be conveniently tuned through varying the applied voltage. Our approach based on electro-assisted manipulations of liquids marbles represents a robust and feasible template for chemical or biomedical reactions involving multiple reagents and steps. We have demonstrated its potential by performing a chemiluminescence to detect the hydrogen peroxide encapsulated in liquid marbles.

  4. Photon- and meson-induced reactions on the nucleon

    NASA Astrophysics Data System (ADS)

    Feuster, T.; Mosel, U.

    1999-01-01

    Starting from a unitary effective Lagrangian model for the meson-nucleon scattering developed in T. Feuster and U. Mosel, Phys. Rev. 58, 457 (1998), we come to a unified description of both meson scattering and photon-induced reactions on the nucleon. To this end the photon is added perturbatively, yielding both Compton scattering and meson photoproduction amplitudes. In a simultaneous fit to all available data the parameters of the nucleon resonances are extracted. We find that a global fit to the data of the various channels involving the final states γN, πN, ππN, ηN, and KΛ is possible. Especially in eta photoproduction a readjustment of the masses and widths found in the fits to hadronic reactions alone is necessary to describe the data. Only for the D13(1520) do we find a possible disagreement for the helicity couplings extracted using the combined data set and pion photoproduction multipoles alone. The model dependence introduced by the restoration of gauge invariance is discussed and found to be significant mainly for resonances with small helicity couplings.

  5. Physicians' reaction to Chernobyl explosion: lessons in radiation - and cooperation

    SciTech Connect

    Not Available

    1986-08-01

    Although the Soviets originally refused offers of technical assistance from many other nations, they accepted one offer of assistance almost immediately - help in the medical care of those who had been exposed to radiation. The offer to provide medical assistance was initiated by the International Bone Marrow Transplant Registry on April 29 by its chair, Robert Peter Gale, MD, PhD, of the Univ. of California at Los Angeles. It was accepted on May 1. This paper discusses his medical experiences and observations on the Chernobyl accident.

  6. Gravitational radiation reaction and inspiral waveforms in the adiabatic limit.

    PubMed

    Hughes, Scott A; Drasco, Steve; Flanagan, Eanna E; Franklin, Joel

    2005-06-10

    We describe progress evolving an important limit of binaries in general relativity: stellar mass compact objects spiraling into much larger black holes. Such systems are of great observational interest. We have developed tools to compute for the first time the radiation from generic orbits. Using global conservation laws, we find the orbital evolution and waveforms for special cases. For generic orbits, inspirals and waveforms can be found by augmenting our approach with an adiabatic self-force rule due to Mino. Such waveforms should be accurate enough for gravitational-wave searches. PMID:16090377

  7. Radiation-Induced Problems in Colorectal Surgery.

    PubMed

    Ashburn, Jean H; Kalady, Matthew F

    2016-06-01

    Radiotherapy not only plays a pivotal role in the cancer care pathways of many patients with pelvic malignancies, but can also lead to significant injury of normal tissue in the radiation field (pelvic radiation disease) that is sometimes as challenging to treat as the neoplasms themselves. Acute symptoms are usually self-limited and respond to medical therapy. Chronic symptoms often require operative intervention that is made hazardous by hostile surgical planes and unforgiving tissues. Management of these challenging patients is best guided by the utmost caution and humility. PMID:27247532

  8. 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

  9. 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.

  10. RADIATION INDUCED VULCANIZATION OF RUBBER LATEX

    DOEpatents

    Mesrobian, R.B.; Ballantine, D.S.; Metz, D.J.

    1964-04-28

    A method of vulcanizing rubber latex by exposing a mixture containing rubber latex and from about 15 to about 21.3 wt% of 2,5-dichlorostyrene to about 1.1 megarads of gamma radiation while maintaining the temperature of the mixture at a temperature ranging between from about 56 to about 59 deg C is described. (AEC)

  11. Radiation-induced cerebellar chondrosarcoma. Case report

    SciTech Connect

    Bernstein, M.; Perrin, R.G.; Platts, M.E.; Simpson, W.J.

    1984-07-01

    The authors report a case of chondrosarcoma arising in the cerebellum 16 years after treatment of a cerebellar malignant astrocytoma by subtotal resection and irradiation. It is thought that the chondrosarcoma arising within the intracranial cavity was a probable consequence of previous ionizing radiation.

  12. Radiatively induced Fermi scale and unification

    NASA Astrophysics Data System (ADS)

    Alanne, Tommi; Meroni, Aurora; Sannino, Francesco; Tuominen, Kimmo

    2016-05-01

    We consider extensions of the Standard Model in which the hierarchy between the unification and the Fermi scale emerges radiatively. Within the Pati-Salam framework, we show that it is possible to construct a viable model where the Higgs is an elementary pseudo-Goldstone boson, and the correct hierarchy is generated.

  13. 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

  14. Single Low-Dose Radiation Induced Regulation of Keratinocyte Differentiation in Calcium-Induced HaCaT Cells

    PubMed Central

    Hahn, Hyung Jin; Youn, Hae Jeong; Cha, Hwa Jun; Kim, Karam; An, Sungkwan

    2016-01-01

    Background We are continually exposed to low-dose radiation (LDR) in the range 0.1 Gy from natural sources, medical devices, nuclear energy plants, and other industrial sources of ionizing radiation. There are three models for the biological mechanism of LDR: the linear no-threshold model, the hormetic model, and the threshold model. Objective We used keratinocytes as a model system to investigate the molecular genetic effects of LDR on epidermal cell differentiation. Methods To identify keratinocyte differentiation, we performed western blots using a specific antibody for involucrin, which is a precursor protein of the keratinocyte cornified envelope and a marker for keratinocyte terminal differentiation. We also performed quantitative polymerase chain reaction. We examined whether LDR induces changes in involucrin messenger RNA (mRNA) and protein levels in calcium-induced keratinocyte differentiation. Results Exposure of HaCaT cells to LDR (0.1 Gy) induced p21 expression. p21 is a key regulator that induces growth arrest and represses stemness, which accelerates keratinocyte differentiation. We correlated involucrin expression with keratinocyte differentiation, and examined the effects of LDR on involucrin levels and keratinocyte development. LDR significantly increased involucrin mRNA and protein levels during calcium-induced keratinocyte differentiation. Conclusion These studies provide new evidence for the biological role of LDR, and identify the potential to utilize LDR to regulate or induce keratinocyte differentiation. PMID:27489424

  15. 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.

  16. Radiation recall dermatitis induced by trastuzumab.

    PubMed

    Moon, Dochang; Koo, Ja Seung; Suh, Chang-Ok; Yoon, Chang Yun; Bae, Jaehyun; Lee, Soohyeon

    2016-01-01

    We report a case of radiation recall dermatitis caused by trastuzumab. A 55-year-old woman with metastatic breast cancer received palliative first-line trastuzumab/paclitaxel and a salvage partial mastectomy with lymph node dissection was subsequently performed. In spite of the palliative setting, the pathology report indicated that no residual carcinoma was present, and then she underwent locoregional radiotherapy to ensure a definitive response. After radiotherapy, she has maintained trastuzumab monotherapy. Nine days after the fifth cycle of trastuzumab monotherapy, dermatitis in previously irradiated skin developed, with fever. Radiation recall dermatitis triggered by trastuzumab is extremely rare. A high fever developed abruptly with a skin rash. This may be the first case of this sort to be reported. PMID:23543400

  17. Mitigation of radiation induced surface contamination

    DOEpatents

    Klebanoff, Leonard E.; Stulen, Richard H.

    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.

  18. A new theoretical approach to thermonuclear radiative-capture reaction rate

    SciTech Connect

    Funaki, Yasuro; Yabana, Kazuhiro; Akahori, Takahiko

    2012-11-12

    We propose a new computational method for astrophysical reaction rate of radiative capture process, which does not require any solution of scattering problem. It is tested for twobody radiative caputure reaction {sup 16}O({alpha},{gamma}){sup 20}Ne and a comparison is made with an ordinary method solving two-body scattering problem. The method is shown to work well in practice and thus will be useful for problems in which an explicit construction of scattering solution is difficult such as the triple-alpha capture process.

  19. DECOHERENCE EFFECTS OF MOTION-INDUCED RADIATION

    SciTech Connect

    P. NETO; D. DALVIT

    2000-12-01

    The radiation pressure coupling with vacuum fluctuations gives rise to energy damping and decoherence of an oscillating particle. Both effects result from the emission of pairs of photons, a quantum effect related to the fluctuations of the Casimir force. We discuss different alternative methods for the computation of the decoherence time scale. We take the example of a spherical perfectly-reflecting particle, and consider the zero and high temperature limits. We also present short general reviews on decoherence and dynamical Casimir effect.

  20. Step-by-Step Simulation of Radiation Chemistry Using Green Functions for Diffusion-Influenced Reactions

    NASA Technical Reports Server (NTRS)

    Plante, Ianik; Cucinotta, Francis A.

    2011-01-01

    Radiolytic species are formed approximately 1 ps after the passage of ionizing radiation through matter. After their formation, they diffuse and chemically react with other radiolytic species and neighboring biological molecules, leading to various oxidative damage. Therefore, the simulation of radiation chemistry is of considerable importance to understand how radiolytic species damage biological molecules [1]. The step-by-step simulation of chemical reactions is difficult, because the radiolytic species are distributed non-homogeneously in the medium. Consequently, computational approaches based on Green functions for diffusion-influenced reactions should be used [2]. Recently, Green functions for more complex type of reactions have been published [3-4]. We have developed exact random variate generators of these Green functions [5], which will allow us to use them in radiation chemistry codes. Moreover, simulating chemistry using the Green functions is which is computationally very demanding, because the probabilities of reactions between each pair of particles should be evaluated at each timestep [2]. This kind of problem is well adapted for General Purpose Graphic Processing Units (GPGPU), which can handle a large number of similar calculations simultaneously. These new developments will allow us to include more complex reactions in chemistry codes, and to improve the calculation time. This code should be of importance to link radiation track structure simulations and DNA damage models.

  1. Photonuclear and radiative capture reaction rates for Nuclear Astrophysics

    NASA Astrophysics Data System (ADS)

    Beard, Mary; Frauendorf, S.; Kaempfer, B.; Scwengner, R.; Wiescher, M.

    2011-10-01

    The vast majority of nuclei heavier than iron are synthesisized via the capture of neutrons. There are however 35 naturally occurring nuclei, including isotopes of Mo and La, located on the neutron-deficient size of the valley of stability. It has been proposed that these nuclei, referred to as p-nuclei, are produced via sequential photo-dissociation reactions in the oxygen-neon shell burning regions of a pre-supernova star. As such, cross sections for p-nuclei production are particularly sensitive to the gamma-ray strength function, which, though dominated by the giant dipole resonance, may contain extra strength contributions near to the neutron threshold. Recently new (γ, γ') cross section measurements have been performed at the ELBE facility at Helmholtz-Zentrum Dresden-Rossendorf for the nuclei ^92-100Mo, ^88Sr, ^90Zr and ^139La probing the photo-absorption cross section over an energy range 4.5 - 6 MeV, up to the neutron separation threshold. The use of these measurements as a test of existing gamma-ray strength function models, and the consequent impact on p-nuclei production rates, will be discussed.

  2. Radiative ion beams: hot stellar reactions in the laboratory

    SciTech Connect

    Haight, R.C.; Mathews, G.J.; Bauer, R.W.

    1984-09-01

    Following our initial production of beams of /sup 7/Be and /sup 13/N, we have improved the purity and intensity of these beams. In addition we have generated beams of /sup 15/O (at 30 MeV) and /sup 8/Li (at 22 MeV). These beams are intended for cross section measurements of proton and alpha-particle capture reactions on unstable species that are important in hot stellar environments. We have begun studies aimed toward measuring the /sup 1/H(/sup 7/Be,/sup 8/B)..gamma.. cross section. As part of the developmental work, we attempted to remeasure the /sup 2/H(/sup 7/Be,/sup 8/B)n cross section with a different technique that pointed out the importance of background /sup 8/Li. We measured the /sup 2/H(/sup 7/Li,/sup 8/Li)/sup 1/H cross section to be 155 +- 20 mb at 12.2 +- 1.3 MeV.

  3. 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.

  4. Equation of motion with radiation reaction in ultrarelativistic laser-electron interactions

    SciTech Connect

    Seto, Keita; Nagatomo, Hideo; Mima, Kunioki; Koga, James

    2011-12-15

    The intensity of the ultra-short pulse lasers has reached 10{sup 22} W/cm{sup 2} owing to the advancements of laser technology. When the motion of an electron becomes relativistic, bremsstrahlung accompanies it. The energy from this bremsstrahlung corresponds to the energy loss of the electron; therefore, the motion of the electron deviates from the case without radiation. The radiation behaves something like resistance. This effect called ''radiation reaction'' or ''radiation damping'' and the force converted from the radiation is named the ''radiation reaction force'' or the ''damping force''. The equation of motion with the reaction force is known as the Lorentz-Abraham-Dirac (LAD) equation, but the solution of this equation is not physical due to the fact that it has a ''run-away'' solution. As one solution of this problem, we have derived a new equation which takes the place of the Lorentz-Abraham-Dirac equation. We will show the validity of this equation with a simple theoretical analysis.

  5. Siderite breakdown and pressure induced Fe-C redox reactions

    NASA Astrophysics Data System (ADS)

    Lavina, Barbara; Dera, Przemyslaw; Kim, Eunja; Downs, Robert T.

    2010-05-01

    Siderite, FeCO3, was investigated at high pressure (up to ~ 40 GPa) and high temperature (up to about 2400K) using a laser heated diamond anvil cell. The structure of the sample was probed with a synchrotron monochromatic beam; powder, multigrain and single crystaldiffraction techniques were used according to changing size of the crystallites in the course of the experiment. At about 35 GPa we observed the breakdown of the carbonate into h-Fe3O4 (the orthorhombic high pressure phase of Fe3O4[1]) and undetected carbon phases. We suggest the breakdown was achieved through a redox reaction where the iron formal valence is increased at the expense of the carbon reduction. This observation is in agreement with results of shock experiments on siderite [2-4] in which however the presence of hematite in the starting material prevented to discriminate among possible reactions determining the synthesis of Fe3O4. Oxygen fugacity and the crystal chemistry of deep Earth mineral assemblages exert a major control on ionic speciation, therefore experimental confirmation are necessary to determine the actual redox equilibrium between iron and carbon in the mantle. Remarkably, perovskite strongly favor the partitioning of Fe3+ [5] and so it might favor the C reduction. If the pressure effect on Fe-C redox equilibrium found in this experiment is active in the deep Earth, the speciation of carbon would be strongly affected, in particular, the stability of carbonates and CO2 might be controlled by pressure induced reductions rather than by the stability of the pure phases. Carbon reduction at pressure might account for the greater subduction of carbon with respect to hydrogen [6]. On the other hand uplifting of reduced carbon assembly might release C-O fluids through reduction of Fe3+. Our results suggest that Fe-C redox reactions might have a crucial role on the carbon speciation which has a major importance on deep Earth processes. References [1] Haavik, et al. (2000) American

  6. Process and Radiation Induced Defects in Electronic Materials and Devices

    NASA Technical Reports Server (NTRS)

    Washington, Kenneth; Fogarty, T. N.

    1997-01-01

    Process and radiation induced defects are characterized by a variety of electrical techniques, including capacitance-voltage measurements and charge pumping. Separation of defect type into stacking faults, displacement damage, oxide traps, interface states, etc. and their related causes are discussed. The defects are then related to effects on device parameters. Silicon MOS technology is emphasized. Several reviews of radiation effects and silicon processing exist.

  7. MHD flow past a parabolic flow past an infinite isothermal vertical plate in the presence of thermal radiation and chemical reaction

    NASA Astrophysics Data System (ADS)

    Muthucumaraswamy, R.; Sivakumar, P.

    2016-02-01

    The problem of MHD free convection flow with a parabolic starting motion of an infinite isothermal vertical plate in the presence of thermal radiation and chemical reaction has been examined in detail in this paper. The fluid considered here is a gray, absorbing emitting radiation but a non-scattering medium. The dimensionless governing coupled linear partial differential equations are solved using the Laplace transform technique. A parametric study is performed to illustrate the influence of the radiation parameter, magnetic parameter, chemical reaction parameter, thermal Grashof number, mass Grashof number, Schmidt number and time on the velocity, temperature, concentration. The results are discussed graphically and qualitatively. The numerical results reveal that the radiation induces a rise in both the velocity and temperature, and a decrease in the concentration. The model finds applications in solar energy collection systems, geophysics and astrophysics, aerospace and also in the design of high temperature chemical process systems.

  8. Radiation-induced products of peptides and their enzymatic digestibility

    SciTech Connect

    Gajewski, E.

    1983-01-01

    Chemical characterization of radiation-induced products of peptides and proteins is essential for understanding the effect of ionizing radiation on peptides and proteins. Furthermore, peptides containing radiation-altered amino acid residues might not be completely digestible by proteolytic enzymes. In this work, small homopeptides of Ala, Phe and Met were chosen as model peptides. Lysozyme was used to investigate the effect of ionizing radiation on a small protein. All peptides and lysozyme were irradiated in diluted, oxygen free, N/sub 2/O-saturated aqueous solutions, using a /sup 60/Co-..gamma..-source. HPLC, capillary GC and GC-MS were applied to isolate and characterize the radiation-induced products. The enzymatic digestibility of the products was investigated using aminopeptidase M, leucine aminopeptidase, carboxypeptidase A and carboxypeptidase Y. It was found that irradiation of peptides examined in this work leads to racemization and alteration of amino acid residues and crosslinks between the peptide chains. In addition, it was established that exopeptidases act differently on radiation-induced dimers of peptides composed of aliphatic, aromatic and sulfur-containing amino acids.

  9. 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.

  10. Selenoprotein P Inhibits Radiation-Induced Late Reactive Oxygen Species Accumulation and Normal Cell Injury

    SciTech Connect

    Eckers, Jaimee C.; Kalen, Amanda L.; Xiao, Wusheng; Sarsour, Ehab H.; Goswami, Prabhat C.

    2013-11-01

    Purpose: Radiation is a common mode of cancer therapy whose outcome is often limited because of normal tissue toxicity. We have shown previously that the accumulation of radiation-induced late reactive oxygen species (ROS) precedes cell death, suggesting that metabolic oxidative stress could regulate cellular radiation response. The purpose of this study was to investigate whether selenoprotein P (SEPP1), a major supplier of selenium to tissues and an antioxidant, regulates late ROS accumulation and toxicity in irradiated normal human fibroblasts (NHFs). Methods and Materials: Flow cytometry analysis of cell viability, cell cycle phase distribution, and dihydroethidium oxidation, along with clonogenic assays, were used to measure oxidative stress and toxicity. Human antioxidant mechanisms array and quantitative real-time polymerase chain reaction assays were used to measure gene expression during late ROS accumulation in irradiated NHFs. Sodium selenite addition and SEPP1 overexpression were used to determine the causality of SEPP1 regulating late ROS accumulation and toxicity in irradiated NHFs. Results: Irradiated NHFs showed late ROS accumulation (4.5-fold increase from control; P<.05) that occurs after activation of the cell cycle checkpoint pathways and precedes cell death. The mRNA levels of CuZn- and Mn-superoxide dismutase, catalase, peroxiredoxin 3, and thioredoxin reductase 1 increased approximately 2- to 3-fold, whereas mRNA levels of cold shock domain containing E1 and SEPP1 increased more than 6-fold (P<.05). The addition of sodium selenite before the radiation treatment suppressed toxicity (45%; P<.05). SEPP1 overexpression suppressed radiation-induced late ROS accumulation (35%; P<.05) and protected NHFs from radiation-induced toxicity (58%; P<.05). Conclusion: SEPP1 mitigates radiation-induced late ROS accumulation and normal cell injury.