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1

Tryptophan Cluster Protects Human ?D-Crystallin from Ultraviolet Radiation-Induced Photoaggregation  

E-print Network

Exposure to ultraviolet radiation (UVR) is a significant risk factor for age-related cataract, a disease of the human lens and the most prevalent cause of blindness in the world. Cataract pathology involves protein misfolding ...

Schafheimer, Steven Nathaniel

2

Light-induced liquid crystallinity.  

PubMed

Liquid crystals are traditionally classified as thermotropic, lyotropic or polymeric, based on the stimulus that governs the organization and order of the molecular system. The most widely known and applied class of liquid crystals are a subset of thermotropic liquid crystals known as calamitic, in which adding heat can result in phase transitions from or into the nematic, cholesteric and smectic mesophases. Photoresponsive liquid-crystal materials and mixtures can undergo isothermal phase transitions if light affects the order parameter of the system within a mesophase sufficiently. In nearly all previous examinations, light exposure of photoresponsive liquid-crystal materials and mixtures resulted in order-decreasing photo-induced isothermal phase transitions. Under specialized conditions, an increase in order with light exposure has been reported, despite the tendency of the photoresponsive liquid-crystal system to reduce order in the exposed state. A direct, photo-induced transition from the isotropic to the nematic phase has been observed in a mixture of spiropyran molecules and a nematic liquid crystal. Here we report a class of naphthopyran-based materials that exhibit photo-induced conformational changes in molecular structure capable of yielding order-increasing phase transitions. Appropriate functionalization of the naphthopyran molecules leads to an exceedingly large order parameter in the open form, which results in a clear to strongly absorbing dichroic state. The increase in order with light exposure has profound implications in optics, photonics, lasing and displays and will merit further consideration for applications in solar energy harvesting. The large, photo-induced dichroism exhibited by the material system has been long sought in ophthalmic applications such as photochromic and polarized variable transmission sunglasses. PMID:22596158

Kosa, Tamas; Sukhomlinova, Ludmila; Su, Linli; Taheri, Bahman; White, Timothy J; Bunning, Timothy J

2012-05-17

3

The influence of crystallinity on radiation stability of UHMWPE  

NASA Astrophysics Data System (ADS)

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

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

2013-03-01

4

Experimental hydrothermal alteration of crystalline and radiation-damaged pyrochlore  

E-print Network

Experimental hydrothermal alteration of crystalline and radiation-damaged pyrochlore T. Geisler pyrochlore phase with a larger unit-cell and a sharp chemical gradient at the interface (on a nm scale observations resemble those made on natural samples. They indicate that the processes of the fluid-pyrochlore

Paris-Sud XI, Université de

5

Locating microearthquakes induced by hydraulic fracturing in crystalline rock  

Microsoft Academic Search

Microearthquakes induced by hydraulic fracturing in crystalline rock at a depth of 3.5 km were located with a precision of better than 30 m to obtain information about the geometry and dimensions of the fracture system produced. The induced microseismicity was monitored by a network of five vorehole seismic stations; a total of about 800 induced events were reliably located

Leigh House

1987-01-01

6

The Molecular Chaperone ?-Crystallin Inhibits UV-Induced Protein Aggregation  

Microsoft Academic Search

Solutions of ?-crystallin, and various enzymes, at neutral pH and 24–26°C, became turbid upon exposure to UV radiation at 295 or 308 nm. SDS-PAGE analysis revealed interchain cross-linking and aggregate formation compared to dark control solutions as reported previously. When ?-crystallin was added to the protein solutions in stoichiometric amounts, UV irradiation resulted in significantly less turbidity than in the

RAYMOND F. BORKMAN; GRADY KNIGHT; BETTIE OBI

1996-01-01

7

Radiation stability test on multiphase glass ceramic and crystalline ceramic waste forms  

NASA Astrophysics Data System (ADS)

A radiation stability study was performed on glass ceramic and crystalline ceramic waste forms. These materials are candidate host materials for immobilizing alkali/alkaline earth (Cs/Sr-CS) + lanthanide (LN) + transition metal (TM) fission product waste streams from nuclear fuel reprocessing. In this study, glass ceramics were fabricated using a borosilicate glass as a matrix in which to incorporate CS/LN/TM combined waste streams. The major phases in these multiphase materials are powellite, oxyaptite, pollucite, celsian, and durable residual glass phases. Al2O3 and TiO2 were combined with these waste components to produce multiphase crystalline ceramics containing hollandite-type phases, perovskites, pyrochlores and other minor metal titanate phases. For the radiation stability test, selected glass ceramic and crystalline ceramic samples were exposed to different irradiation environments including low fluxes of high-energy (?1-5 MeV) protons and alpha particles generated by an ion accelerator, high fluxes of low-energy (hundreds of keV) krypton particles generated by an ion implanter, and in-situ electron irradiations in a transmission electron microscope. These irradiation experiments were performed to simulate self-radiation effects in a waste form. Ion irradiation-induced microstructural modifications were examined using X-ray diffraction and transmission electron microscopy. Our preliminary results reveal different radiation tolerance in different crystalline phases under various radiation damage environments. However, their stability may be rate dependent which may limit the waste loading that can be achieved.

Tang, Ming; Kossoy, Anna; Jarvinen, Gordon; Crum, Jarrod; Turo, Laura; Riley, Brian; Brinkman, Kyle; Fox, Kevin; Amoroso, Jake; Marra, James

2014-05-01

8

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

PubMed

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

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

2014-08-01

9

Amyloid Fiber Formation in Human ?D-Crystallin Induced by UV-B Photodamage  

PubMed Central

?D-crystallin is an abundant structural protein of the lens that is found in native and modified forms in cataractous aggregates. We establish that UV-B irradiation of ?D-crystallin leads to structurally specific modifications and precipitation via two mechanisms: amorphous aggregates and amyloid fibers. UV-B radiation causes cleavage of the backbone, in large measure near the interdomain interface, where side chain oxidations are also concentrated. 2D IR spectroscopy and expressed protein ligation localize fiber formation exclusively to the C-terminal domain of ?D-crystallin. The native ?-sandwich domains are not retained upon precipitation by either mechanism. The similarity between the amyloid forming pathway when induced by either UV-B radiation or low pH suggests that it is the propensity for the C-terminal ?-sandwich domain to form amyloid ?-sheets that determines the misfolding pathway independent of the mechanism of denaturation. PMID:23957864

Moran, Sean D.; Zhang, Tianqi O.; Decatur, Sean M.; Zanni, Martin T.

2013-01-01

10

Radiation Induced Genomic Instability  

PubMed Central

Radiation induced genomic instability can be observed in the progeny of irradiated cells multiple generations after irradiation of parental cells. The phenotype is well established both in vivo (Morgan 2003) and in vitro (Morgan 2003), and may be critical in radiation carcinogenesis (Little 2000, Huang et al. 2003). Instability can be induced by both the deposition of energy in irradiated cells as well as by signals transmitted by irradiated (targeted) cells to non-irradiated (non-targeted) cells (Kadhim et al. 1992, Lorimore et al. 1998). Thus both targeted and non-targeted cells can pass on the legacy of radiation to their progeny. However the radiation induced events and cellular processes that respond to both targeted and non-targeted radiation effects that lead to the unstable phenotype remain elusive. PMID:21556289

Morgan, William F.

2011-01-01

11

Radiation-induced pneumothorax  

SciTech Connect

Pneumothorax is an uncommon complication of radiation therapy to the chest. The proposed pathogenesis is radiation-induced fibrosis promoting subpleural bleb formation that ruptures resulting in pneumothorax. We report on two young patients with primary sarcomas without pulmonary metastases who developed spontaneous pneumothorax after irradiation. Neither patient had antecedent radiographic evidence of pulmonary fibrosis.

Epstein, D.M.; Littman, P.; Gefter, W.B.; Miller, W.T.; Raney, R.B. Jr.

1983-01-01

12

Growth Induced Magnetic Anisotropy in Crystalline and Amorphous Thin Films  

SciTech Connect

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

Hellman, Frances

1998-10-03

13

Radiation-induced sarcoma  

Microsoft Academic Search

Opinion statement  Radiation-induced sarcomas can originate in either the irradiated bone or soft tissues. Most of these tumors are high-grade.\\u000a The most common histologic subtypes are malignant fibrous histiocytoma (MFH) and osteosarcoma, although other histologies\\u000a (eg, angiosarcoma, rhabdomyosarcoma) can occur. Tumor size and grade are the two most important prognostic factors for soft tissue\\u000a sarcomas, including those associated with radiation therapy.

Shreyaskumar R. Patel

2000-01-01

14

Radiation-Induced Bioradicals  

NASA Astrophysics Data System (ADS)

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.

Lahorte, Philippe; Mondelaers, Wim

15

Radiation-induced schwannomas  

SciTech Connect

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.

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

1989-06-01

16

Radiation Induced Genomic Instability  

SciTech Connect

Radiation induced genomic instability can be observed in the progeny of irradiated cells multiple generations after irradiation of parental cells. The phenotype is well established both in vivo (Morgan 2003) and in vitro (Morgan 2003), and may be critical in radiation carcinogenesis (Little 2000, Huang et al. 2003). Instability can be induced by both the deposition of energy in irradiated cells as well as by signals transmitted by irradiated (targeted) cells to non-irradiated (non-targeted) cells (Kadhim et al. 1992, Lorimore et al. 1998). Thus both targeted and non-targeted cells can pass on the legacy of radiation to their progeny. However the radiation induced events and cellular processes that respond to both targeted and non-targeted radiation effects that lead to the unstable phenotype remain elusive. The cell system we have used to study radiation induced genomic instability utilizes human hamster GM10115 cells. These cells have a single copy of human chromosome 4 in a background of hamster chromosomes. Instability is evaluated in the clonal progeny of irradiated cells and a clone is considered unstable if it contains three or more metaphase sub-populations involving unique rearrangements of the human chromosome (Marder and Morgan 1993). Many of these unstable clones have been maintained in culture for many years and have been extensively characterized. As initially described by Clutton et al., (Clutton et al. 1996) many of our unstable clones exhibit persistently elevated levels of reactive oxygen species (Limoli et al. 2003), which appear to be due dysfunctional mitochondria (Kim et al. 2006, Kim et al. 2006). Interestingly, but perhaps not surprisingly, our unstable clones do not demonstrate a “mutator phenotype” (Limoli et al. 1997), but they do continue to rearrange their genomes for many years. The limiting factor with this system is the target – the human chromosome. While some clones demonstrate amplification of this chromosome and thus lend 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.

Morgan, William F.

2011-03-01

17

Radiation-induced Fibrosarcoma  

PubMed Central

Six cases of fibrosarcoma arising in previously irradiated tissues are reported, out of a total of 220 cases of fibrosarcoma treated at Mount Vernon Hospital during the last 23 years. This rare occurrence may follow at any interval from 3 to 38 years after irradiation, usually after high dosage. Four of our six cases are known to have died of the disease. The literature regarding radiation-induced fibrosarcoma is reviewed and it is suggested that adequate excision or amputation may be curative, if undertaken early enough. ImagesFig. 5Figs. 6-8Figs. 9-11Figs. 1-4 PMID:5503597

Gane, N. F. C.; Lindup, Rhona; Strickland, P.; Bennett, M. H.

1970-01-01

18

Induced seismicity in crystalline basement: Understanding the reasons  

NASA Astrophysics Data System (ADS)

In recent years, cases of induced seismicity have been reported for geothermal wells in aseismic regions. The use of geothermal energy naturally influences the reservoir as heat and water are withdrawn. However, most geothermal plants reinject the water so that pressure levels within the reservoir remain more or less stable. Despite this and despite low injection pressures, some of these reinjecting plants experience induced seismicity. One example is the well Unterhaching Gt2, close to Munich, Germany. Here, the reservoir is an approximately 500 m thick karstified limestone layer of the Upper Jurassic, in which extraction and reinjection take place. Flow rates of more than 100 l/s have been established with reinjection pressures below 10 bar. Nevertheless, induced seismicity occurs. Most of the events are below 1.0 but some reach up to 2.4 on the Richter scale. Due to their location, they can without any doubt be attributed to the reinjection process. However, the origin of the quakes is not within the reservoir but located in the crystalline basement. As the reinjection well cuts through a steeply inclined fault, a hydraulic connection between reservoir, borehole and basement is given if a hydraulically open fault is assumed. So far, it was impossible to find a correlation between the occurrence of induced seismicity and operating parameters of the geothermal plant like flow rate, injection pressure, or temperature. Therefore, thermo-hydraulic-mechanical numerical models of the subsurface have been developed to understand the interaction between different parameters and to possibly identify critical thresholds for the initiation of induced seismicity. Due to the large scale of the model, several kilometers in each direction, an equivalent porosity approach has been chosen for the hydraulic modeling of the karstic limestone layer. Flow within in the fault is also described by Darcy's law as the fault is not assumed to be a surface but a volume. This assumption is based on the analysis of seismic data of this region, which indicate a zone of damaged rock several tens of meters in diameter. Because of this approach to model the hydraulics, the pore pressure within the fault will most likely be the determining factor for the onset of induced seismicity. Therefore, it is of high interest to analyse the influence of the operating parameters of the geothermal plant on this parameter.

Schumacher, Sandra

2014-05-01

19

Experimental hydrothermal alteration of crystalline and radiation-damaged pyrochlore  

NASA Astrophysics Data System (ADS)

We have performed hydrothermal experiments with a crystalline microlite and a heavily self-irradiation-damaged (i.e., X-ray amorphous) betafite in a solution containing 1 mol/l HCl and 1 mol/l CaCl 2 at 175 °C for 14 days. The well-crystalline microlite grains were partly (˜5-10 ?m rim) replaced by a Ca and Na-poorer, defect pyrochlore phase with a larger unit-cell and a sharp chemical gradient at the interface (on a nm scale) to the unreacted core. The amorphous betafite grains (up to ˜2 mm in diameter), on the other hand, were completely transformed into an intergrowth of different crystalline phases (polycrystalline anatase and rutile, a yet unidentified Nb-Ta oxide, and a Y-REE phase), showing complex non-equilibrium structures. Our experimental observations bear a remarkable resemblance to those made on natural samples. They indicate that the processes of the fluid-pyrochlore interaction are influenced by self-irradiation structural damage and that thermodynamic equilibrium models can hardly be applied to adequately describe such systems.

Geisler, T.; Seydoux-Guillaume, A.-M.; Poeml, P.; Golla-Schindler, U.; Berndt, J.; Wirth, R.; Pollok, K.; Janssen, A.; Putnis, A.

2005-09-01

20

The molecular chaperone alpha-crystallin inhibits UV-induced protein aggregation.  

PubMed

Solutions of gamma-crystallin, and various enzymes, at neutral pH and 24-26 degrees C, became turbid upon exposure to UV radiation at 295 or 308 nm. SDS-PAGE analysis revealed interchain cross-linking and aggregate formation compared to dark control solutions as reported previously. When alpha-crystallin was added to the protein solutions in stoichiometric amounts, UV irradiation resulted in significantly less turbidity than in the absence of alpha-crystallin. For example, addition of 0.5 mg of alpha-crystallin to 0.5 mg of gamma-crystallin in 1.0 ml solution yielded only 25% of the turbidity seen in the absence of alpha-crystallin. Addition of 2.0 mg of alpha-crystallin resulted in 20% of the turbidity. Given the molecular weights of alpha- and gamma-crystallin (about 800 kDa and 20 kDa, respectively), a gamma/alpha 1:1 weight ratio corresponds to a 40:1 molar ratio, and a gamma/alpha 1:4 weight ratio corresponds to a 10:1 molar ratio. Hence, the molar ratio of alpha-crystallin needed to effectively protect gamma-crystallin from photochemical opacification was gamma/alpha = n:1, where n was in the range 10-40. In terms of subunits, this ratio is gamma/alpha = 1:m, where m = 1-4. Thus, each gamma-crystallin molecule needs 1-4 alpha subunits for protection. Similar stoichiometries were observed for protection of the other proteins studied. The protection stems in part from screening of UV radiation by alpha-crystallin but more importantly from a chaperone effect analogous to that seen in thermal aggregation experiments. PMID:8698074

Borkman, R F; Knight, G; Obi, B

1996-02-01

21

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

PubMed Central

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

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

2014-01-01

22

Radiation-induced genomic instability  

NASA Technical Reports Server (NTRS)

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.

Kronenberg, A.

1994-01-01

23

Crystalline polymorphism induced by charge regulation in ionic membranes  

PubMed Central

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

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

2013-01-01

24

Radiation-induced intestinal inflammation  

PubMed Central

Radiation induces an important inflammatory response in the irradiated organs, characterized by leukocyte infiltration and vascular changes that are the main limiting factor in the application of this therapeutic modality for the treatment of cancer. Recently, a considerable investigative effort has been directed at determining the molecular mechanisms by which radiation induces leukocyte recruitment, in order to create strategies to prevent intestinal inflammatory damage. In these review, we consider current available evidence on the factors governing the process of leukocyte recruitment in irradiated organs, mainly derived from experimental studies, with special attention to adhesion molecules, and their value as therapeutic targets. PMID:17589918

Molla, Meritxell; Panes, Julian

2007-01-01

25

Radiation-induced cardiovascular effects  

NASA Astrophysics Data System (ADS)

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.

Tapio, Soile

26

Radiation-induced myelomatosis.  

PubMed

It is well known that radiation can cause myeloid leukemia. However, no excess of chronic lymphocytic leukemia has been observed. Myelomatosis, like chronic lymphocytic leukemia, is a tumor of B lymphocytes. To determine whether this disease has a radiogenic origin, we surveyed all cohorts of persons exposed to radiation for which data on cancer-related mortality are available. An excess of myeloma was found in most cohorts. However, a striking deficit was found in two groups irradiated intensely for uterine neoplasms (three cases observed, 10.71 expected; P = 0.012). All other groups combined had a highly significant excess (50 observed, 22.21 expected; P = 2 X 10(-7)). The largest relative risk appeared among persons receiving internal doses of alpha-particles (14 observed, 3.24 expected; P = 2 X 10(-5)), but a significant excess (13 observed, 6.33 expected; P = 0.026) was also found in patients receiving only therapeutic or diagnostic gamma-rays or x-rays. Most cases occurred 15 to 25 years after exposure. PMID:7442744

Cuzick, J

1981-01-22

27

Tensile and tribological properties of high-crystallinity radiation crosslinked UHMWPE.  

PubMed

Osteolysis due to particulate wear debris associated with ultrahigh molecular weight polyethylene (UHMWPE) components of total joint replacement prostheses has been a major factor determining their in vivo lifetime. In recent years, radiation crosslinking has been employed to decrease wear rates in PE components, especially in acetabular cups of total hip replacement prostheses. A drawback of radiation crosslinking is that it leads to a crosslinked PE (or XPE) with lower mechanical properties compared with uncrosslinked PE. In contrast, high-crystallinity PEs are known to have several mechanical properties higher than conventional PE. In this study, we hypothesized that increasing the crystallinity of radiation crosslinked and remelted XPE would result in an increase in tensile properties without compromising wear resistance. High-pressure crystallization was performed on PE and XPE and analyzed for the resulting morphological alterations using differential scanning calorimeter, low voltage scanning electron microscopy, and ultrasmall angle X-ray scattering. Uniaxial tensile tests showed that high-pressure crystallization increased the tensile modulus and yield stress in both PE and XPE, decreased the ultimate strain and ultimate stress in PE but had no significant effect on ultimate strain or ultimate stress in XPE. Multidirectional wear tests demonstrated that high-pressure crystallization decreased the wear resistance of PE but had no effect on the wear resistance of XPE. In conclusion, this study shows that high-pressure crystallization can be effectively used to increase the crystallinity and modulus of XPE without compromising its superior wear resistance compared with PE. PMID:18985795

Bistolfi, Alessandro; Turell, Mary Beth; Lee, Ying-Lung; Bellare, Anuj

2009-07-01

28

Tensile and tribological properties of high-crystallinity radiation crosslinked UHMWPE  

SciTech Connect

Osteolysis due to particulate wear debris associated with ultrahigh molecular weight polyethylene (UHMWPE) components of total joint replacement prostheses has been a major factor determining their in vivo lifetime. In recent years, radiation crosslinking has been employed to decrease wear rates in PE components, especially in acetabular cups of total hip replacement prostheses. A drawback of radiation crosslinking is that it leads to a crosslinked PE (or XPE) with lower mechanical properties compared with uncrosslinked PE. In contrast, high-crystallinity PEs are known to have several mechanical properties higher than conventional PE. In this study, we hypothesized that increasing the crystallinity of radiation crosslinked and remelted XPE would result in an increase in tensile properties without compromising wear resistance. High-pressure crystallization was performed on PE and XPE and analyzed for the resulting morphological alterations using differential scanning calorimeter, low voltage scanning electron microscopy, and ultrasmall angle X-ray scattering. Uniaxial tensile tests showed that high-pressure crystallization increased the tensile modulus and yield stress in both PE and XPE, decreased the ultimate strain and ultimate stress in PE but had no significant effect on ultimate strain or ultimate stress in XPE. Multidirectional wear tests demonstrated that high-pressure crystallization decreased the wear resistance of PE but had no effect on the wear resistance of XPE. In conclusion, this study shows that high-pressure crystallization can be effectively used to increase the crystallinity and modulus of XPE without compromising its superior wear resistance compared with PE.

Bistolfi, Alessandro; Turell, Mary Beth; Lee, Ying-Lung; Bellare, Anuj; (BWH)

2009-09-02

29

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

E-print Network

EFFECT OF LASER INDUCED CRYSTALLINITY MODIFICATION ON BIODEGRADATION PROFILE OF POLY(L-LACTIC ACID attention due to their biocompatibility and biodegradability. Being biodegradable, poly(L-lactic acid) (PLLA it favorable in drug delivery because it hydrolyzes in the human body into lactic acid, which is then excreted

Yao, Y. Lawrence

30

Hydrogeologic controls on induced seismicity in crystalline basement rocks due to fluid injection into basal reservoirs.  

PubMed

A series of Mb 3.8-5.5 induced seismic events in the midcontinent region, United States, resulted from injection of fluid either into a basal sedimentary reservoir with no underlying confining unit or directly into the underlying crystalline basement complex. The earthquakes probably occurred along faults that were likely critically stressed within the crystalline basement. These faults were located at a considerable distance (up to 10?km) from the injection wells and head increases at the hypocenters were likely relatively small (?70-150?m). We present a suite of simulations that use a simple hydrogeologic-geomechanical model to assess what hydrogeologic conditions promote or deter induced seismic events within the crystalline basement across the midcontinent. The presence of a confining unit beneath the injection reservoir horizon had the single largest effect in preventing induced seismicity within the underlying crystalline basement. For a crystalline basement having a permeability of 2?×?10(-17) ?m(2) and specific storage coefficient of 10(-7) /m, injection at a rate of 5455?m(3) /d into the basal aquifer with no underlying basal seal over 10?years resulted in probable brittle failure to depths of about 0.6?km below the injection reservoir. Including a permeable (kz ?=?10(-13) ?m(2) ) Precambrian normal fault, located 20?m from the injection well, increased the depth of the failure region below the reservoir to 3?km. For a large permeability contrast between a Precambrian thrust fault (10(-12) ?m(2) ) and the surrounding crystalline basement (10(-18) ?m(2) ), the failure region can extend laterally 10?km away from the injection well. PMID:23745958

Zhang, Yipeng; Person, Mark; Rupp, John; Ellett, Kevin; Celia, Michael A; Gable, Carl W; Bowen, Brenda; Evans, James; Bandilla, Karl; Mozley, Peter; Dewers, Thomas; Elliot, Thomas

2013-01-01

31

Pressure-induced transformations in crystalline and vitreous PbGeO 3  

Microsoft Academic Search

Structural transitions in crystalline and vitreous PbGeO3 were studied at pressures up to 20 GPa. Crystalline PbGeO3 was observed to undergo a pressure-induced amorphization between 12–18 GPa. Vitreous PbGeO3 was found to exhibit an amorphous-to-amorphous transition in a similar pressure range. The structural and thermal properties of the pressure-cycled PbGeO3 materials were further studied with high-energy x-ray diffraction and differential scanning calorimetry.

Erin N. Oelker; M. Harish Bhat; Emmanuel Soignard; Jeffery L. Yarger

2009-01-01

32

Radiation-induced esophageal carcinoma  

Microsoft Academic Search

Radiation-induced carcinoma of the esophagus is rare and only 8 cases have been reported since 1957. This article presents 2 additional patients in whom esophageal carcinoma developed in segments previously exposed to large therapeutic doses of irradiation. The first patient had received 5,000 rads to her mediastinum and the second patient 3,200 rads to her neck region. The latent intervals

Elizabeth W. O'Connell; William B. Seaman; Gary G. Ghahremani

1984-01-01

33

Endotoxin-Induced Structural Transformations in Liquid Crystalline Droplets  

NASA Astrophysics Data System (ADS)

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

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

2011-06-01

34

Radiation induced estane polymer crosslinking  

SciTech Connect

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.

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

1997-12-01

35

Ultrasound visualization of internal crystalline lens deformation using laser-induced microbubbles  

NASA Astrophysics Data System (ADS)

The progressive loss of accommodation of the eye, called presbyopia, affects people with age and can result in a complete loss of accommodation by about age 55 years. It is generally accepted that presbyopia is due to an increase in stiffness of the lens. With increasing age, the stiffness of the crystalline lens nucleus increases faster than that of the cortex. During accommodation, the deformation of different parts of the crystalline lens is different and likely changes with age. However, a direct observation of crystalline lens deformation and strain distribution is difficult because although imaging methods such as OCT or Scheimpflug imaging can distinguish cortex and nucleus, they cannot determine their regional deformation. Here, patterns of laser-induced microbubbles were created in gelatin phantoms and different parts of excised animal crystalline lenses and their displacements in response to external deformation were tracked by ultrasound imaging. In the animal lenses, the deformation of the lens cortex was greater than that of nucleus and this regional difference is greater for a 27-month-old bovine lens than for a 6-month-old porcine lens. This approach enables visualization of localized, regional deformation of crystalline lenses and, if applied to lenses from animal species that undergo accommodation, may help to understand the mechanisms of accommodation and presbyopia, improve diagnostics, and, potentially, aid in the development of new methods of lens modifying presbyopia treatments.

Karpiouk, Andrei B.; Aglyamov, Salavat R.; Glasser, Adrian; Emelianov, Stanislav Y.

2014-02-01

36

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

NASA Technical Reports Server (NTRS)

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

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

1992-01-01

37

Shock induced radiation from minerals  

NASA Technical Reports Server (NTRS)

Schmitt and Ahrens (1983) have concluded that the type of optical emission produced during shock compression was dependent upon phase changes taking place during shock compression. The present study is concerned with new observations of shock-induced optical radiation from Al2O3, MgO, NaCl, KCl, x-cut and fused SiO2, and LiF at various pressures up to 75 GPa. The experimental setup used in the study is similar to that employed by Schmitt and Ahrens. An Image Converter Camera with a three-frame plug-in unit was added to take two or three exposures of the radiation field during shock wave propagation through the sample, taking into account exposure times in the range from 50 to 500 nsec. The greybody emissions observed in LiF, which undergoes no phase transition, imply that localized heating and perhaps melting occurs in this material during shock deformation.

Schmitt, D.; Svendsen, B.; Ahrens, T. J.

1985-01-01

38

Radiation-induced leiomyosarcoma of the oropharynx  

PubMed Central

Leiomyosarcoma is a malignant mesenchymal tumor originating from smooth muscle cells, which most frequently develops in the myometrium and in the gastro-intestinal tract. Reviewing the international literature, radiation-induced sarcoma arise in 0.035 to 0.2 % of all irradiated patients. Especially in the head and neck region, radiation-induced leiomyosarcoma is an extremely rare lesion. The authors report a case of a radiation-induced leiomyosarcoma of the tonsillar region of the oropharynx in a 51-year-old male patient, who had undergone radiation therapy of this region 38 years before. The lesion was treated by radical surgery. Diagnostic steps, histological presentation and therapy are described in detail and the literature concerning radiation induced malignancies in general as well as radiation induced leiomyosarcoma in particular is reviewed. The highlights of this case are an extremely uncommon location and a rare pathological entity of radiation induced malignancies. PMID:16925805

Pfeiffer, Jens; Boedeker, Carsten Christof; Ridder, Gerd Jurgen; Maier, Wolfgang; Kayser, Gian

2006-01-01

39

Electron-beam-induced structural changes in crystalline C60 and C70  

NASA Astrophysics Data System (ADS)

High-resolution transmission electron microscopy (HRTEM), electron diffraction, and electron energy-loss spectroscopy (EELS) were used to characterize electron-beam-induced structural transformations in crystalline samples of C60 and C70. During these transformations, the electron-diffraction patterns became progressively more diffuse, with the outer diffraction spots disappearing first, followed in succession by the disappearance of the inner spots. We interpret this course of evolution in the diffraction patterns as evidence of degradation of the crystalline structure via the destruction of individual molecules, as opposed to electron-beam-induced motion of intact fullerene molecules. EELS analyses of the data indicate that the final state of these transformations was amorphous carbon.

Seraphin, Supapan; Zhou, Dan; Jiao, Jun

1993-08-01

40

Control over the crystal phase, crystallinity, morphology of AgVO3 via protein inducing process.  

PubMed

A facile and bio-inspired route for the preparation of pure and highly crystalline metastable ?-AgVO(3) is presented. Three kinds of proteins (bovine hemoglobin, bovine serum albumin, and lysozyme) were employed as inducer, which had substantial effects on the nucleation and growth of ?-AgVO(3). Moreover, the amount of proteins also played a key role over the morphology and crystalline of products. The VO(3)(-)/protein complex acted as a driver to induce the formation of metastable phase, which was confirmed by resonance Rayleigh scattering and UV-vis absorption spectra. The results indicated that tailoring an interaction between protein and inorganic molecules was the key in bio-inspired selective synthesis of metastable phase, which may find applications in the design of other new functional inorganic materials. PMID:22014392

Chen, Tao; Shao, Mingwang; Xu, Hongyan; Wen, Chunye; Lee, Shuit-Tong

2012-01-15

41

Milling induces disorder in crystalline griseofulvin and order in its amorphous counterpart  

SciTech Connect

This study investigates two apparently similar thermal signatures, shaped as bimodal exotherms, observed when either the crystalline or the amorphous from of the drug are subjected to milling. Crystalline griseofulvin was cryomilled and the (quenched-melt) amorphous form was subjected to either cryomilling or grinding. The thermal and surface properties of the resulting samples were analyzed using differential scanning calorimetry (DSC) and surface energy analysis. After milling, both the crystalline and the amorphous material revealed visually similar bimodal exothermic events when the heating rate was 20 C min{sup -1}. Under different heating rates, the pair of DSC peaks for the bimodal exotherm of each material behaved entirely different from each other. The two peaks of the bimodal event, as well as the glass transition, can be kinetically resolved for the ground amorphous form using standard mode DSC. In contrast, similar analysis was unable to resolve the bimodal exotherm or a glass transition in the case of the cryomilled crystals. Furthermore, cryomilled crystals do not exhibit a glass transition even when analyzed using modulated DSC. Synchrotron sourced X-ray analysis revealed that grinding the amorphous material results in the nucleation and growth of the crystalline form. Milling thus induces disorder in the crystals of griseofulvin but induces order in the amorphous form of the drug. The surface of the two milled systems consistently exhibited different energetics under a wide range of relative humidity conditions. These findings suggest that cryomilling induces both bulk and surface disorder, specifically, a certain level of dislocations on the crystal. In contrast, grinding the amorphous material lowers the activation energy for crystal formation, inducing nuclei formation and growth throughout the amorphous matrix.

Otte, Andrew; Zhang, Yan; Carvajal, M. Teresa; Pinal, Rodolfo (Purdue)

2012-04-02

42

Light induced degradation in promising multi-crystalline silicon materials for solar cell fabrication  

Microsoft Academic Search

Light induced degradation (LID) in boron doped Czochralski (Cz) silicon with high oxygen content is known to degrade solar cell efficiency. Multicrystalline Si crystals also have oxygen and use B doping, but LID effects are largely unknown. In this paper, ribbon, Cz, and cast multi-crystalline Si crystals with a resistivity of 1-3 \\/spl Omega\\/cm were investigated for LID. 15-16% efficient

B. Damiani; K. Nakayashiki; D. S. Kim; V. Yelundur; S. Ostapenko; I. Tarasov; A. Rohatgi

2003-01-01

43

Effect of heat-induced structural perturbation of secondary and tertiary structures on the chaperone activity of alpha-crystallin.  

PubMed

alpha-Crystallin, a major protein of the lens, is known to have chaperone activity to protect other proteins against thermal aggregation. Heat-induced structural change of alpha-crystallin was previously shown to increase its chaperone activity. In this report, we studied the thermal reversibility of alpha-crystallin and the effect of change in secondary structure on its chaperone function in vitro. The heat-induced conformational changes in the aromatic region of near-UV CD spectra showed only a small degree of reversibility. The structural transitions from 50 to 70 degrees C were largely reversible if the incubation time was short. However, the protective ability to inhibit thermal aggregation of alcohol dehydrogenase by alpha-crystallin was essentially similar at 48 and 70 degrees C. Under long-term heating at high temperatures, there was a time-dependent irreversibility of structural change in alpha-crystallin as revealed by CD spectroscopy. Such denatured alpha-crystallin by long-term heating can still preserve its ability to prevent UV-induced aggregation of gamma-crystallin at room temperature, indicating relatively little effect of heat-induced changes in secondary structure on the chaperone activity of alpha-crystallin. PMID:9268700

Lee, J S; Satoh, T; Shinoda, H; Samejima, T; Wu, S H; Chiou, S H

1997-08-18

44

Elevated expression of alphaA- and alphaB-crystallins in streptozotocin-induced diabetic rat.  

PubMed

alpha-Crystallin, a predominant protein of the ocular lens, is composed of two subunits, alphaA and alphaB. Of these, alphaB-crystallin has been shown to present widely in non-lenticular tissues while alphaA-crystallin is largely lens-specific. Although, expression of alphaB-crystallin is elevated under various stress and pathological conditions, yet its physiological significance remained unknown. Some studies suggest that the expression of alphaB-crystallin gene is related to oxidative stress. Persistent hyperglycemia during uncontrolled diabetes is known to cause oxidative stress, which has been implicated in various secondary complications of diabetes. Hence, expression of alphaA- and alphaB-crystallins in various tissues of streptozotocin (STZ)-induced diabetic Wistar-NIN rats was investigated by RT-PCR and immunoblotting. While expression of alphaB-crystallin was noted in the wide range of tissues examined in the study, alphaA-crystallin expression was detected only in lens and retina. Interestingly, alphaB-crystallin expression was elevated in lens, heart, muscle, and brain, but decreased in adipose tissue of diabetic rats compared to control rats. alphaA-Crystallin expression was increased in retina of diabetic rat. Increased oxidative stress appears to be a major stimulus for the enhanced expression of alphaA- and alphaB-crystallins in the tissues of diabetic rats and elevated expression of alpha-crystallin may have a protective role against metabolic stress. Interestingly, feeding of curcumin, a dietary antioxidant, to diabetic rats attenuated the enhanced expression of alphaB-crystallin. The results indicate that elevated expression of alpha-crystallins in some tissues may have implications in pathophysiology of diabetic complications. PMID:16309625

Kumar, P Anil; Haseeb, Abdul; Suryanarayana, P; Ehtesham, Nasreen Z; Reddy, G Bhanuprakash

2005-12-15

45

Thermal Stress Induced Aggregation of Aquaporin 0 (AQP0) and Protection by ?-Crystallin via Its Chaperone Function  

PubMed Central

Aquaporin 0 (AQP0) formerly known as membrane intrinsic protein (MIP), is expressed exclusively in the lens during terminal differentiation of fiber cells. AQP0 plays an important role not only in the regulation of water content but also in cell-to-cell adhesion of the lens fiber cells. We have investigated the thermal stress-induced structural alterations of detergent (octyl glucoside)-solubilized calf lens AQP0. The results show an increase in the amount of AQP0 that aggregated as the temperature increased from 40°C to 65°C. ?-Crystallin, molecular chaperone abundantly present in the eye lens, completely prevented the AQP0 aggregation at a 1?1 (weight/weight) ratio. Since ?-crystallin consists of two gene products namely ?A- and ?B-crystallins, we have tested the recombinant proteins on their ability to prevent thermal-stress induced AQP0 aggregation. In contrast to the general observation made with other target proteins, ?A-crystallin exhibited better chaperone-like activity towards AQP0 compared to ?B-crystallin. Neither post-translational modifications (glycation) nor C-terminus truncation of AQP0 have any appreciable effect on its thermal aggregation properties. ?-Crystallin offers similar protection against thermal aggregation as in the case of the unmodified AQP0, suggesting that ?crystallin may bind to either intracellular loops or other residues of AQP0 that become exposed during thermal stress. Far-UV circular dichroism studies indicated a loss of ?helical structures when AQP0 was subjected to temperatures above 45°C, and the presence of ?-crystallin stabilized these secondary structures. We report here, for the first time, that ?-crystallin protects AQP0 from thermal aggregation. Since stress-induced structural perturbations of AQP0 may affect the integrity of the lens, presence of the molecular chaperone, ?-crystallin (particularly ?A-crystallin) in close proximity to the lens membrane is physiologically relevant. PMID:24312215

Swamy-Mruthinti, Satyanarayana; Srinivas, Volety; Hansen, John E.; Rao, Ch Mohan

2013-01-01

46

Thermal stress induced aggregation of aquaporin 0 (AQP0) and protection by ?-crystallin via its chaperone function.  

PubMed

Aquaporin 0 (AQP0) formerly known as membrane intrinsic protein (MIP), is expressed exclusively in the lens during terminal differentiation of fiber cells. AQP0 plays an important role not only in the regulation of water content but also in cell-to-cell adhesion of the lens fiber cells. We have investigated the thermal stress-induced structural alterations of detergent (octyl glucoside)-solubilized calf lens AQP0. The results show an increase in the amount of AQP0 that aggregated as the temperature increased from 40°C to 65°C. ?-Crystallin, molecular chaperone abundantly present in the eye lens, completely prevented the AQP0 aggregation at a 1?1 (weight/weight) ratio. Since ?-crystallin consists of two gene products namely ?A- and ?B-crystallins, we have tested the recombinant proteins on their ability to prevent thermal-stress induced AQP0 aggregation. In contrast to the general observation made with other target proteins, ?A-crystallin exhibited better chaperone-like activity towards AQP0 compared to ?B-crystallin. Neither post-translational modifications (glycation) nor C-terminus truncation of AQP0 have any appreciable effect on its thermal aggregation properties. ?-Crystallin offers similar protection against thermal aggregation as in the case of the unmodified AQP0, suggesting that ?crystallin may bind to either intracellular loops or other residues of AQP0 that become exposed during thermal stress. Far-UV circular dichroism studies indicated a loss of ?helical structures when AQP0 was subjected to temperatures above 45°C, and the presence of ?-crystallin stabilized these secondary structures. We report here, for the first time, that ?-crystallin protects AQP0 from thermal aggregation. Since stress-induced structural perturbations of AQP0 may affect the integrity of the lens, presence of the molecular chaperone, ?-crystallin (particularly ?A-crystallin) in close proximity to the lens membrane is physiologically relevant. PMID:24312215

Swamy-Mruthinti, Satyanarayana; Srinivas, Volety; Hansen, John E; Rao, Ch Mohan

2013-01-01

47

Study of molecular mechanisms of UV-induced aggregation of crystallins and possibility of maintaining eye lens transparency  

NASA Astrophysics Data System (ADS)

The effect of D-pantethine and L-carnosine on the rate of UV-induced (XeC1 laser ? = 308 nm) aggregation of a mixture of ?L-crystallin and ?-crystallin is studied. We also demonstrate that the suggested by us combination of short-chain peptides shows better protective properties with respect to UV-induced aggregation than known anti-cataract agents.

Soustov, L. V.; Chelnokov, E. V.; Bityurin, N. M.; Kiselev, A. L.; Nemov, V. V.; Sergeev, Yu. V.; Ostrovsky, M. A.

2006-03-01

48

Radiation-induced moyamoya syndrome  

SciTech Connect

Purpose: The moyamoya syndrome is an uncommon late complication after radiotherapy (RT). Methods and Materials: A PubMed search of English-language articles, with radiation, radiotherapy, and moyamoya syndrome used as search key words, yielded 33 articles from 1967 to 2002. Results: The series included 54 patients with a median age at initial RT of 3.8 years (range, 0.4 to 47). Age at RT was less than 5 years in 56.3%, 5 to 10 years in 22.9%, 11 to 20 years in 8.3%, 21 to 30 years in 6.3%, 31 to 40 years in 2.1%, and 41 to 50 years in 4.2%. Fourteen of 54 patients (25.9%) were diagnosed with neurofibromatosis type 1 (NF-1). The most common tumor treated with RT was low-grade glioma in 37 tumors (68.5%) of which 29 were optic-pathway glioma. The average RT dose was 46.5 Gy (range, 22-120 Gy). For NF-1-positive patients, the average RT dose was 46.5 Gy, and for NF-1-negative patients, it was 58.1 Gy. The median latent period for development of moyamoya syndrome was 40 months after RT (range, 4-240). Radiation-induced moyamoya syndrome occurred in 27.7% of patients by 2 years, 53.2% of patients by 4 years, 74.5% of patients by 6 years, and 95.7% of patients by 12 years after RT. Conclusions: Patients who received RT to the parasellar region at a young age (<5 years) are the most susceptible to moyamoya syndrome. The incidence for moyamoya syndrome continues to increase with time, with half of cases occurring within 4 years of RT and 95% of cases occurring within 12 years. Patients with NF-1 have a lower radiation-dose threshold for development of moyamoya syndrome.

Desai, Snehal S. [Department of Radiology, Division of Radiation Oncology, Baylor College of Medicine, Methodist Hospital, Houston, TX (United States); Paulino, Arnold C. [Department of Radiology, Division of Radiation Oncology, Baylor College of Medicine, Methodist Hospital, Houston, TX (United States)]. E-mail: apaulino@tmh.tmc.edu; Mai, Wei Y. [Department of Radiology, Division of Radiation Oncology, Baylor College of Medicine, Methodist Hospital, Houston, TX (United States); Teh, Bin S. [Department of Radiology, Division of Radiation Oncology, Baylor College of Medicine, Methodist Hospital, Houston, TX (United States)

2006-07-15

49

Micromechanical Modeling of Anisotropic Damage-Induced Permeability Variation in Crystalline Rocks  

NASA Astrophysics Data System (ADS)

This paper presents a study on the initiation and progress of anisotropic damage and its impact on the permeability variation of crystalline rocks of low porosity. This work was based on an existing micromechanical model considering the frictional sliding and dilatancy behaviors of microcracks and the recovery of degraded stiffness when the microcracks are closed. By virtue of an analytical ellipsoidal inclusion solution, lower bound estimates were formulated through a rigorous homogenization procedure for the damage-induced effective permeability of the microcracks-matrix system, and their predictive limitations were discussed with superconducting penny-shaped microcracks, in which the greatest lower bounds were obtained for each homogenization scheme. On this basis, an empirical upper bound estimation model was suggested to account for the influences of anisotropic damage growth, connectivity, frictional sliding, dilatancy, and normal stiffness recovery of closed microcracks, as well as tensile stress-induced microcrack opening on the permeability variation, with a small number of material parameters. The developed model was calibrated and validated by a series of existing laboratory triaxial compression tests with permeability measurements on crystalline rocks, and applied for characterizing the excavation-induced damage zone and permeability variation in the surrounding granitic rock of the TSX tunnel at the Atomic Energy of Canada Limited's (AECL) Underground Research Laboratory (URL) in Canada, with an acceptable agreement between the predicted and measured data.

Chen, Yifeng; Hu, Shaohua; Zhou, Chuangbing; Jing, Lanru

2014-09-01

50

Medium-induced multi-photon radiation  

E-print Network

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 Moli\\`{e}re limit. We find that in this limit the LPM effect holds for medium-induced two-photon ladder emission.

Hao Ma; Carlos A. Salgado; Konrad Tywoniuk

2011-05-29

51

Large deformation compression induced crystallinity degradation of conventional and highly crosslinked UHMWPEs.  

PubMed

The effect of a large compressive plastic deformation on the melt temperature (Tm), lamellar thickness, crystallinity, and density of four UHMWPEs (two conventional and two highly crosslinked) was examined. The materials were prepared from a single batch of medical grade GUR 1050 resin (Ticona, Bayport, TX, USA). The two conventional UHMWPEs were as-received (virgin) and gamma radiation sterilized at 30 kGy in a nitrogen atmosphere (radiation sterilized). The two highly crosslinked UHMWPEs were each irradiated at 100 kGy and then post-processed with one of either two thermal treatments: annealing, which was done below the melt transition temperature (Tm), at 110 degrees C for 2h (110 degrees C-annealed); and, remelting, which was done above Tm, at 150 degrees C (150 degrees C-remelted). Differences in changes upon compression between the materials were examined using ANCOVA analyses. The 150 degrees C-remelted material showed a significant change in Tm and lamellar thickness upon compressive plastic deformation whereas the other three UHMWPE materials did not. However, all of the materials showed significantly decreased crystallinity and density upon compressive deformation. The findings of this study support that microstructural evolution during compressive deformation is a function of UHMWPE formulation, as affected by irradiation and post-irradiation heat treatment. PMID:15935468

Sobieraj, Michael C; Kurtz, Steven M; Rimnac, Clare M

2005-11-01

52

Molecular insights into the progression of crystalline silica-induced pulmonary toxicity in rats.  

PubMed

Identification of molecular target(s) and mechanism(s) of silica-induced pulmonary toxicity is important for the intervention and/or prevention of diseases associated with exposure to silica. Rats were exposed to crystalline silica by inhalation (15 mg m(-3), 6 h per day, 5 days) and global gene expression profile was determined in the lungs by microarray analysis at 1, 2, 4, 8 and 16 weeks following termination of silica exposure. The number of significantly differentially expressed genes (>1.5-fold change and <0.01 false discovery rate P-value) detected in the lungs during the post-exposure time intervals analyzed exhibited a steady increase in parallel with the progression of silica-induced pulmonary toxicity noticed in the rats. Quantitative real-time PCR analysis of a representative set of 10 genes confirmed the microarray findings. The number of biological functions, canonical pathways and molecular networks significantly affected by silica exposure, as identified by the bioinformatics analysis of the significantly differentially expressed genes detected during the post-exposure time intervals, also exhibited a steady increase similar to the silica-induced pulmonary toxicity. Genes involved in oxidative stress, inflammation, respiratory diseases, cancer, and tissue remodeling and fibrosis were significantly differentially expressed in the rat lungs; however, unresolved inflammation was the single most significant biological response to pulmonary exposure to silica. Excessive mucus production, as implicated by significant overexpression of the pendrin coding gene, SLC26A4, was identified as a potential novel mechanism for silica-induced pulmonary toxicity. Collectively, the findings of our study provided insights into the molecular mechanisms underlying the progression of crystalline silica-induced pulmonary toxicity in the rat. Published 2012. This article is a US Government work and is in the public domain in the USA. PMID:22431001

Sellamuthu, Rajendran; Umbright, Christina; Roberts, Jenny R; Cumpston, Amy; McKinney, Walter; Chen, Bean T; Frazer, David; Li, Shengqiao; Kashon, Michael; Joseph, Pius

2013-04-01

53

Crystalline Grain Growth in the Lateral Direction for Silicon Thin Films by Electrical Current-Induced Joule Heating  

Microsoft Academic Search

Large crystalline grain growth was demonstrated for 60-nm-thick silicon films using the electrical-current-induced joule heating method. Tapered electrodes were used in order to ensure distribution of the joule heating intensity in the lateral direction along the surface in silicon strips. Melting of silicon for 17 mus caused by the joule heating resulted in the formation of 4-8-mum-long crystalline grains. The

Nobuyuki Andoh; Toshiyuki Sameshima

2002-01-01

54

Radiation-induced changes in bone.  

PubMed

Radiation therapy has important applications in curative, adjuvant, and palliative therapy for a wide range of malignant conditions. Evidence of radiation therapy may be seen on radiologic images obtained subsequent to therapy. Bone growth disturbances may be observed in the immature axial or appendicular skeleton. Complications in the mature skeleton include osteoradionecrosis, pathologic fracture, and radiation-induced neoplasms. Radiologic features of mandibular osteoradionecrosis include ill-defined cortical destruction without sequestration. In osteoradionecrosis of the ribs, clavicle, scapula, and humerus, radiography may demonstrate osteopenia, disorganization and coarsening of trabecular architecture, and cortical irregularity; computed tomography more clearly depicts subtle fractures, alterations in bone architecture, and dystrophic soft-tissue calcification. In osteoradionecrosis of the spine, hematopoietic cellular elements of the spinal marrow are replaced with fat, which has high signal intensity on T1-weighted magnetic resonance images and intermediate signal intensity on T2-weighted images. Radiation-induced changes in the pelvis include osteopenia, increased bone density, and widening and irregularity of the sacroiliac joints. Radiation-induced osteochondromas are radiographically identical to those that arise spontaneously. Radiographic findings in radiation-induced sarcoma demonstrate an aggressive pattern of bone destruction. Awareness of the varied radiographic manifestations of radiation-induced changes in bone and correlation with clinical features and the radiation field will usually allow distinction of these changes from those associated with other pathologic conditions. PMID:9747611

Mitchell, M J; Logan, P M

1998-01-01

55

Radiation-induced genomic instability: radiation quality and dose response  

NASA Technical Reports Server (NTRS)

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.

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

2003-01-01

56

Radiation-Induced Grafting on Polyamides.  

National Technical Information Service (NTIS)

The objective of the project was to investigate radiation-induced grafting on polyamides, with emphasis on fluorine-containg vinyl monomers. The principal experimental technique was the gamma ray irradiation of polyamide film samples immersed in suitable ...

J. E. Wilson

1972-01-01

57

Radiation-induced accelerated coronary arteriosclerosis  

SciTech Connect

There is a paucity of information on radiation-induced coronary heart disease. A young patient with myocardial infarction following mediastinal irradiation is described. The role of radiotherapy and chemotherapy on the subsequent development of coronary heart disease is discussed.

Mittal, B.; Deutsch, M.; Thompson, M.; Dameshek, H.L.

1986-07-01

58

Medium-induced gluon radiation: an update  

E-print Network

The theory of radiative parton energy loss in a static QCD medium is updated. We show that for an incoming parton of large energy $E$ undergoing a hard, small angle scattering in the medium rest frame (i.e., $p_\\perp /E \\ll 1$ with $p_\\perp$ the final parton transverse momentum), the medium-induced radiative energy loss due to soft rescatterings is proportional to $E$. It arises from gluon radiation with large formation time $t_f \\gg L$, i.e., fully coherent over the size $L$ of the medium. In particular, in a physical (light-cone) gauge, the medium-induced radiation spectrum arises from the interference between initial and final state radiation. This result, rigorously derived to all orders in the opacity expansion, invalidates a common belief that any medium-induced energy loss through a finite size target should be bounded in the high-energy limit. We also review the case of a parton suddenly annihilated (created) in the hard process, where the bound on energy loss applies. In this case the induced gluon radiation reduces to purely initial (final) state radiation, and the fully coherent part of the radiation cancels out, leaving only a contribution from $t_f \\lesssim L$. As is well-known, in the high energy limit the resulting parton energy loss is independent of $E$ (neglecting logarithms) and proportional to $L^2$.

Stéphane Peigné; François Arleo; Rodion Kolevatov

2014-02-07

59

Radiation-induced lung injury  

SciTech Connect

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.

Rosiello, R.A.; Merrill, W.W. (Yale Univ. Medical Center, New Haven, CT (USA))

1990-03-01

60

Light-induced point defect reactions of residual iron in crystalline silicon after aluminum gettering  

SciTech Connect

Deep level transient spectroscopy is used to study light-induced reactions of residual iron impurities after aluminum gettering (AlG) in crystalline silicon. White-light illumination at room temperature leads to the formation of a defect which is associated with a donor level at 0.33 eV above the valence band. This defect is stable up to about 175 deg. C where it dissociates reversibly in case of small iron concentrations and irreversibly for high iron concentrations. Since marker experiments using gold and platinum diffusion show a high vacancy concentration after AlG a tentative identification of the new defect as the metastable iron-vacancy pair is proposed.

Abdelbarey, D.; Kveder, V.; Schroeter, W.; Seibt, M. [IV. Physikalisches Institut der Georg-August-Universitaet Goettingen, Friedrich-Hund-Platz 1, D-37077 Goettingen (Germany)

2010-08-15

61

On the pressure-induced loss of crystallinity in orthophosphates of zinc and calcium  

NASA Astrophysics Data System (ADS)

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

Shakhvorostov, Dmitry; Müser, Martin H.; Mosey, Nicholas J.; Munoz-Paniagua, David J.; Pereira, Gavin; Song, Yang; Kasrai, Masoud; Norton, Peter R.

2008-02-01

62

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

SciTech Connect

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

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

2008-01-01

63

Radiation-induced intracranial malignant gliomas  

SciTech Connect

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.

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

1989-07-01

64

Channeling and Radiation of Electrons in Silicon Single Crystals and Si1-xGex Crystalline Undulators  

NASA Astrophysics Data System (ADS)

The phenomenon of channeling and the basic features of channeling radiation emission are introduced in a pedestrian way. Both, radiation spectra as well as dechanneling length measurements at electron beam energies between 195 and 855 MeV feature quantum state phenomena for the (110) planar potential of the silicon single crystals. Radiation from a crystalline undulator, produced at the Aarhus University (UAAR), has been investigated at the Mainz Microtron electron accelerator facility MAMI. The 4-period epitaxially grown strained layer Si1-xGex undulator had a period length ?u = 9.9 ?m. At a beam energy of 375 MeV a broad excess yield around the theoretically expected photon energy of 0.132 MeV has been observed. Model calculations on the basis of synchrotron-like radiation emission suggest that evidence for a weak undulator effect has been observed.

Backe, H.; Krambrich, D.; Lauth, W.; Andersen, K. K.; Lundsgaard Hansen, J.; Uggerhøj, Ulrik I.

2013-06-01

65

Radiation-induced transgenerational instability.  

PubMed

To date, the analysis of mutation induction has provided an irrefutable evidence for an elevated germline mutation rate in the parents directly exposed to ionizing radiation and a number of chemical mutagens. However, the results of numerous publications suggest that radiation may also have an indirect effect on genome stability, which is transmitted through the germ line of irradiated parents to their offspring. This review describes the phenomenon of transgenerational instability and focuses on the data showing increased cancer incidence and elevated mutation rates in the germ line and somatic tissues of the offspring of irradiated parents. The possible mechanisms of transgenerational instability are also discussed. PMID:14557814

Dubrova, Yuri E

2003-10-13

66

Polyaniline fibers, films, and powders: X-ray studies of crystallinity and stress-induced preferred orientation  

SciTech Connect

Powder (hk0) and four-circle X-ray diffractometry are used to study the effects of hot-stretching on films and fibers of the emeralidine base form of polyaniline (EB-II). It is shown definitively that hot-stretching induces nucleation of new crystalline material rather than growth and/or orientation of pre-existing crystallites. The diffuse scattering from amorphous EB-II is dominated by short-range interchain correlations and develops preferred orientation in response to stretching but with a broader mosaic than the crystalline phase. For the maximally-stretched samples, the crystal fractions was determined by accounting for the different mosaic distributions of crystalline and amorphous phases, correcting for the mass of N-methylphenazolinium plasticizer and ruling out any significant contribution from NMP diffuse scattering to the amorphous EB-II profiles. Films stretched to L/L[sub 0] = 4.25 contain no more than 4% crystalline material while fibers with L/L[sub 0] = 4.5 are 24--30% crystalline. These fractional crystallinity values are significantly small than found for EB-II powder (60%). More importantly, these results have implications for models of electric properties which invoke interchain interactions.

Fischer, J.E.; Zhu, Q.; Tang, X.; Scherr, E.M.; MacDiarmid, A.G. (Univ. of Pennsylvania, Philadelphia, PA (United States). Lab. for Research on the Structure of Matter); Cajipe, V.B. (CNRS-UMR 110, Nantes (France). Inst. des Materiaux des Nantes)

1994-08-29

67

Radiation-induced nickel deposits  

NASA Technical Reports Server (NTRS)

Low cost, photographic process uses surface coating of nickel hypophosphite sensitive to X-rays and electron radiation. Exposed coated surface can be amplified to produce permanent visible image of wide tonal gradation in grays. Coating may be sodium, ammonium, or lithium hypophosphite or sodium phosphite, with nickel supplied in developer.

Marsik, S. J.; Philipp, W. H.

1972-01-01

68

Radiation-induced instability and its relation to radiation carcinogenesis  

NASA Technical Reports Server (NTRS)

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.

Ullrich, R. L.; Ponnaiya, B.

1998-01-01

69

Two-photon induced exciton mediated dissociation of N20 and photomobility of 0 atoms in crystalline Xe  

E-print Network

Two-photon induced exciton mediated dissociation of N20 and photomobility of 0 atoms in crystalline, California 92717 (Received 7 May 1992; accepted 24 July 1992) Two-photon induced access of Xe excitons at 248 the extracted parameters are the two-photon absorption cross section of Xe at 248 nm, 3.7X 10m4* cm4 s, the free

Apkarian, V. Ara

70

Crystalline Membranes  

NASA Technical Reports Server (NTRS)

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

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

2008-01-01

71

[Transgenerational transmission of radiation induced genomic instability].  

PubMed

Stability of genome is one of the evolutionary important trait of cells. Various mutations (gene, chromosomal, genomic) as well as artificial manipulations with genomes (inbreeding, DNA transfection, introduction of Br-DU in DNA) cause the genetic instability. Ionizing radiation is known as the factor which induced instability of genome in late mitotic descendants of cells after in vitro and in vivo exposure. Radiation induced genetic instability can be transmitted through germline cells. On the cell level both types of radiation induced genomic instability are manifested in elevated frequency of mutations, chromosome aberrations, micronuclei, increased radiosensitivity, disappearance of adaptive response, changes in gene expression. In studies of 1970-1980 years clear evidences on the different morphological and functional injuries in tissues of irradiated organisms as well as in tissues of the progeny of exposed parents were obtained. On the organism level the instability of mitotic and of meiotic progeny of irradiated cells is resulted in increased risk of cancer and of other somatic diseases. It seems to be useful to review the earlier radiobiology literature where delayed and transgenerational effects of ionizing radiation on tissues and on organisms level were clearly shown in animals. For the estimation of pathogenic role of radiation induced genomic instability in humans, particularly in children of exposed parents the parallel study of the same human cohorts using clinical parameters and various characteristic of genomic instability seems to be very important. PMID:17020095

Vorobtsova, I E

2006-01-01

72

Radiation-Induced Phase Transformations in Ilmenite-Group Minerals  

SciTech Connect

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

Mitchell, J. N.

1997-12-31

73

Evaluation of a crystalline nanosuspension: polymorphism, process induced transformation and in vivo studies.  

PubMed

The aim of this work was to evaluate a crystalline nanosuspension of an investigational anticancer compound, SN 30191. Solid forms of SN 30191 were prepared and characterized by thermal analysis, infrared spectroscopy, ¹³C CP/MAS SSNMR spectroscopy, SEM and powder XRD. Wet milling was performed using a high pressure homogenizer and process induced transformations were studied as a function of time and pressure using infrared spectroscopy. Dose-toxicity and pharmacokinetics (PK) of the nanocrystal formulation were evaluated in mice after intravenous administration. SN 30191 was found to exist in two polymorphic forms (I and II) and a hydrate with an equilibrium solubility < 0.1 ?g/ml (pH 1.3-11.0, 37 °C). Wet milling resulted in solid state transformation as a function of pressure. Form II was found to transform into form I at intermediate pressures. A further increase in pressure resulted in formation of a hydrate. The final nanosuspension consisted of SN 30191 as a hydrate. The dose-toxicity studies revealed higher tolerance (~4 times) for the nanosuspension (10 mg/kg) when compared with a solution formulation (2.5 mg/kg). Compared with solution formulation, the nanosuspension allowed the delivery of a higher dose and rendered possible the performance of PK and tissue distribution studies in animals. PMID:21272627

Sharma, Puneet; Zujovic, Zoran D; Bowmaker, Graham A; Marshall, Andrew J; Denny, William A; Garg, Sanjay

2011-04-15

74

Quercetin inhibits radiation-induced skin fibrosis.  

PubMed

Radiation induced fibrosis of the skin is a late toxicity that may result in loss of function due to reduced range of motion and pain. The current study sought to determine if oral delivery of quercetin mitigates radiation-induced cutaneous injury. Female C3H/HeN mice were fed control chow or quercetin-formulated chow (1% by weight). The right hind leg was exposed to 35 Gy of X rays and the mice were followed serially to assess acute toxicity and hind leg extension. Tissue samples were collected for assessment of soluble collagen and tissue cytokines. Human and murine fibroblasts were subjected to clonogenic assays to determine the effects of quercetin on radiation response. Contractility of fibroblasts was assessed with a collagen contraction assay in the presence or absence of quercetin and transforming growth factor-? (TGF-?). Western blotting of proteins involved in fibroblast contractility and TGF-? signaling were performed. Quercetin treatment significantly reduced hind limb contracture, collagen accumulation and expression of TGF-? in irradiated skin. Quercetin had no effect on the radioresponse of fibroblasts or murine tumors, but was capable of reducing the contractility of fibroblasts in response to TGF-?, an effect that correlated with partial stabilization of phosphorylated cofilin. Quercetin is capable of mitigating radiation induced skin fibrosis and should be further explored as a therapy for radiation fibrosis. PMID:23819596

Horton, Jason A; Li, Fei; Chung, Eun Joo; Hudak, Kathryn; White, Ayla; Krausz, Kristopher; Gonzalez, Frank; Citrin, Deborah

2013-08-01

75

Radiation-induced cancer: a modern view  

PubMed Central

Diagnostic medical radiation has been the most rapidly increasing component of population background radiation exposure in Western countries over the past decade. This trend is set to increase as CT scanning is readily available with burgeoning use in everyday clinical practice. Consequently, the issue of cancer induction from the doses received during diagnostic medical exposures is highly relevant. In this review we explain current understanding of potential cancer induction at low doses of sparsely ionising radiation. For cancers that may be induced at low doses, a mechanistic description of radiation-induced cancer is discussed, which, in combination with extrapolation of data based on population cohort studies, provides the basis of the currently accepted linear no-threshold model. We explore the assumptions made in deriving risk estimates, the controversies surrounding the linear no-threshold model and the potential future challenges facing clinicians and policy-makers with regards to diagnostic medical radiation and cancer risk, most notably the uncertainties regarding deriving risk estimates from epidemiological data at low doses. PMID:23175483

Shah, D J; Sachs, R K; Wilson, D J

2012-01-01

76

Delayed Radiation-Induced Vasculitic Leukoencephalopathy  

SciTech Connect

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.

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

2012-05-01

77

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

E-print Network

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

Qi, Xuele

2011-02-22

78

Radiation-induced mutation at minisatellite loci  

SciTech Connect

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.

Dubrova, Y.E. [Univ. of Leicester (United Kingdom)]|[Vavilov Institute of General Genetics, Moscow (Russian Federation); Nesterov, V.N.; Krouchinsky, N.G. [Research Institute for Radiation Medicine, Mogilev (Belarus)] [and others

1997-10-01

79

Heat pump processes induced by laser radiation  

NASA Technical Reports Server (NTRS)

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.

Garbuny, M.; Henningsen, T.

1980-01-01

80

Radiation induced dynamic mutations and transgenerational effects.  

PubMed

Many studies have confirmed that radiation can induce genomic instability in whole body systems. Although the molecular mechanisms underlying induced genomic instability are not known at present, this interesting phenomenon could be the manifestation of a cellular fail-safe system in which fidelity of repair and replication is down-regulated to tolerate DNA damage. Two features of genomic instability namely, delayed mutation and untargeted mutation, require two mechanisms of ;damage memory' and ;damage sensing, signal transduction and execution' to induce mutations at a non damaged-site. In this report, the phenomenon of transgenerational genomic instability and possible mechanisms are discussed using mouse data collected in our laboratory as the main bases. PMID:17019049

Niwa, Ohtsura

2006-01-01

81

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

PubMed

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

Lee, H J; Chang, G G

2000-07-01

82

Pattern of liquid crystalline droplets induced by two beam interference in azobenzene derivative  

NASA Astrophysics Data System (ADS)

A pattern of liquid crystalline droplets dispersed in the isotropic liquid can be formed during illumination by two interfering laser beams in certain range of the temperature and the light intensity. Azobenzene derivative substituted by long alkyl and alkoxy chains exhibiting smectic phases has been used for the study. The pattern can be reversibly erased and rewritten by shutting down and opening of the interfering beams. Polarized microscope images have shown the formation of numerous liquid crystalline droplets at bright regions of the interference fringes. Influence of the temperature and the light intensity has been studied by measuring the diffraction efficiency dynamics. Photothermal and photoorientational mechanisms of the formation of liquid crystalline droplets pattern have been proposed and discussed.

Czajkowski, Maciej; Dradrach, Klaudia; Bartkiewicz, Stanislaw; Galewski, Zbigniew

2013-10-01

83

Crystalline Grain Growth in the Lateral Direction for Silicon Thin Films by Electrical Current-Induced Joule Heating  

NASA Astrophysics Data System (ADS)

Large crystalline grain growth was demonstrated for 60-nm-thick silicon films using the electrical-current-induced joule heating method. Tapered electrodes were used in order to ensure distribution of the joule heating intensity in the lateral direction along the surface in silicon strips. Melting of silicon for 17 ?s caused by the joule heating resulted in the formation of 4-8-?m-long crystalline grains. The change in the film thickness was at most 6 nm in the crystallized region. There was a tensile stress of 5.6 × 108 Pa in the film. The heat flow simulation demonstrated that the solidification occurred in the lateral direction according to the temperature gradient and that the solid/liquid interface moved in the lateral direction at the velocity of about 1-2 m/s.

Andoh, Nobuyuki; Sameshima, Toshiyuki

2002-09-01

84

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

E-print Network

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

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

2007-09-14

85

Radiation induced genomic instability in bystander cells  

NASA Astrophysics Data System (ADS)

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

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

86

Nanoparticle-induced widening of the temperature range of liquid-crystalline blue phases  

Microsoft Academic Search

Liquid-crystalline blue phases exhibit exceptional properties for applications in the display and sensor industry. However, in single component systems, they are stable only for very narrow temperature range between the isotropic and the chiral nematic phase, a feature that severely hinders their applicability. Systematic high-resolution calorimetric studies reveal that blue phase III is effectively stabilized in a wide temperature range

Eva Karatairi; Brigita Rozic; Zdravko Kutnjak; Vassilios Tzitzios; George Nounesis; George Cordoyiannis; Jan Thoen; Christ Glorieux; Samo Kralj

2010-01-01

87

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

E-print Network

University, New York, NY 10027 Abstract Poly(L-lactic acid) (PLLA) is of interest in drug delivery: poly(L-lactic acid); laser treatment; biodegradation; crystallinity; drug delivery #12;2 1. Introduction Poly(L-lactic acid) (PLLA) is attractive in drug delivery, food packaging, and tissue engineering

Yao, Y. Lawrence

88

Radiation-Induced Esophagitis Exacerbated by Everolimus  

PubMed Central

Background Everolimus, a potent mammalian target of rapamycin (mTOR) inhibitor, has shown anticancer activity against various types of cancer, including renal cell carcinoma (RCC); however, little information is available on the efficacy and safety of the combination of everolimus and radiotherapy. We report a case of radiation-induced esophagitis that might have been exacerbated by the sequential administration of everolimus. Case Presentation A 63-year-old Japanese man with RCC complained of back pain, and magnetic resonance imaging revealed vertebral metastases. He received radiotherapy (30 Gy/10 fractions) to the T6–10 vertebrae. Everolimus was administered immediately after the completion of radiotherapy. One week later, he complained of dysphagia, nausea and vomiting. An endoscopic examination of the esophagus showed erosive esophagitis in the middle to lower portions of his thoracic esophagus, corresponding to the irradiation field. Conclusion Clinicians should be aware that everolimus might lead to the unexpected exacerbation of radiation toxicities. PMID:23898276

Miura, Yuji; Suyama, Koichi; Shimomura, Akihiko; Miyakawa, Jimpei; Kobayashi, Hiroki; Uki, Akiyoshi; Okaneya, Toshikazu; Takano, Toshimi

2013-01-01

89

Radiation-induced electron migration along DNA  

SciTech Connect

Radiation-induced electron migration along DNA is a mechanism by which randomly produced stochastic energy deposition events can lead to nonrandom types of damage along DNA manifested distal to the sites of the initial energy deposition. Electron migration along DNA is significantly influenced by the DNA base sequence and DNA conformation. Migration along 7 base pairs in oligonucleotides containing guanine bases was observed for oligonucleotides irradiated in solution which compares to average migration distances of 6 to 10 bases for Escherichia coli DNA irradiated in solution and 5.5 base pairs for Escherichia coli DNA irradiated in cells. Evidence also suggests that electron migration can occur preferentially in the 5{prime} to 3{prime} direction along DNA. Our continued efforts will provide information regarding the contribution of electron transfer along DNA to formation of locally multiply damaged sites created in DNA by exposure to ionizing radiation.

Fuciarelli, A.F.; Sisk, E.C.; Miller, J.H. [Pacific Northwest Lab., Richland, WA (United States); Zimbrick, J.D. [National Research Council, Washington, DC (United States)

1994-04-01

90

Radiation induced carcinoma of the larynx  

SciTech Connect

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.

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

1985-07-01

91

Radiation-induced osteosarcoma of the sphenoid bone  

Microsoft Academic Search

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.

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

1989-01-01

92

Countermeasures for Space Radiation Induced Malignancies and Acute Biological Effects  

Microsoft Academic Search

The hypothesis being evaluated in this research program is that control of radiation induced oxidative stress will reduce the risk of radiation induced adverse biological effects occurring as a result of exposure to the types of radiation encountered during space travel. As part of this grant work, we have evaluated the protective effects of several antioxidants and dietary supplements and

Ann Kennedy

2008-01-01

93

Radiation-induced injury of the esophagus  

SciTech Connect

Forty patients with functional or morphologic esophageal abnormalities following radiotherapy were identified. Abnormalities included abnormal motility with and without mucosal edema, stricture, ulceration and pseudodiverticulum, and fistula. Abnormal motility occurred 4 to 12 weeks following radiotherapy alone and as early as 1 week after therapy when concomitant chemotherapy had been given. Strictures developed 4 to 8 months following completion of radiotherapy. Ulceration, pseudodiverticulum, and fistula formation did not develop in a uniform time frame. Radiation-induced esophageal injury is more frequent when radiotherapy and chemotherapy are combined than it is with radiotherapy alone.

Lepke, R.A.; Libshitz, H.I.

1983-08-01

94

Radiation induced micrencephaly in guinea pigs  

SciTech Connect

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.

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

1991-01-01

95

Theory Of Radiation-Induced Attenuation In Optical Fibers  

NASA Technical Reports Server (NTRS)

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.

Liu, Tsuen-Hsi; Johnston, Alan R.

1996-01-01

96

Ion beam induced luminescence: Relevance to radiation induced bystander effects  

NASA Astrophysics Data System (ADS)

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

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

2012-10-01

97

Laser-Induced Forward Transfer-printing of focused ion beam pre-machined crystalline magneto-optic yttrium iron garnet micro-discs.  

PubMed

We present femtosecond laser-induced forward transfer of focused ion beam pre-machined discs of crystalline magneto-optic yttrium iron garnet (YIG) films. Debris-free circular micro-discs with smooth edges and surface uniformity have been successfully printed. The crystalline nature of the printed micro-discs has not been altered by the LIFT printing process, as was confirmed via micro-Raman measurements. PMID:22772215

Sones, C L; Feinaeugle, M; Sposito, A; Gholipour, B; Eason, R W

2012-07-01

98

Morphology-induced redistribution of surface plasmon modes in two-dimensional crystalline gold platelets  

NASA Astrophysics Data System (ADS)

The 2D optical field intensity distribution in sub-micron, ultrathin, and crystalline gold platelets is investigated by two-photon luminescence (TPL) microscopy. In particular, the evolution of the TPL maps as the particle morphology undergoes a transition from triangular to hexagonal reveals that the signatures of the high-order surface plasmon states sustained by the platelets follows the same C3v to C6v symmetry redistribution. Experimental observations are precisely accounted for by theoretical simulations based on the Green dyadic method.

Viarbitskaya, S.; Teulle, A.; Cuche, A.; Sharma, J.; Girard, C.; Dujardin, E.; Arbouet, A.

2013-09-01

99

X-ray scattering and diffraction from ion beam induced ripples in crystalline silicon  

SciTech Connect

We report on periodic ripple formation on Si(001) surfaces after bombardment with Xe{sup +} ions with energies between 5 and 35 keV under incidence angles of 65 deg. and 70 deg. The sputter process leads to the formation of a rippled amorphous surface layer, followed by a rippled interface toward crystalline material. Using grazing-incidence small-angle scattering and diffraction, we show that the surface morphology is exactly reproduced at the interface. In addition, we observe that the crystal lattice close to the interface is anisotropically expanded. The lattice expansion parallel to the ripples is larger than those perpendicular to them.

Biermanns, Andreas; Pietsch, Ullrich [Festkoerperphysik, Universitaet Siegen, 57068 Siegen (Germany); Grenzer, Joerg; Hanisch, Antje; Facsko, Stefan [Institut fuer Ionenstrahlphysik und Materialforschung, Forschungszentrum Dresden-Rossendorf, P.O. Box 510119, 01314 Dresden (Germany); Carbone, Geradina; Metzger, Till Hartmut [ESRF, 6 Rue Jules Horowitz, BP220, F-38043 Grenoble Cedex (France)

2008-08-15

100

INTERACTION OF LASER RADIATION WITH MATTER: Generation of a bleaching wave in an ST-50-1 glass ceramics induced by a Nd:YAG laser  

NASA Astrophysics Data System (ADS)

It is shown that upon exposing glass ceramics to laser radiation for which the initial polycrystalline phase is opaque, whereas the corresponding glass phase is transparent, the transparency oscillations can be produced due to the laser-induced phase transitions from the crystalline to amorphous state and vice versa, resulting in the propagation of a bleaching and darkening wave.

Veiko, V. P.; Novikov, B. Yu; Shakhno, E. A.; Yakovlev, E. B.

2009-01-01

101

Radiation Induced Surface Activity Phenomenon: 2. Report - Radiation Induced Boiling Enhancement  

SciTech Connect

To delineate the effect of Radiation Induced Surface Activity (RISA) on boiling phenomenon, surface wettability in high-temperature environment or Leidenfrost condition and critical heat flux (CHF) of oxide metals irradiated by gamma rays were investigated. When the temperature of the heating surface reaches the wetting limit temperature, water-solid contact vanishes because of a stable vapor film between the droplet and the metal surface, i.e., a Leidenfrost condition. The wetting limit temperature increased with integrated irradiation dose. The CHF of oxidized titanium was improved up to 100% after 800 kGy {sup 60}Co gamma ray irradiated. Radiation Induced Boiling Enhancement (RIBE) phenomenon was firstly confirmed through the experiments. (authors)

Tatsuya Koga; Yasuyuki Imai; Tomoji Takamasa [Tokyo University of Mercantile Marine, 2-1-6 Etchu-jima, Koto-Ku, Tokyo 135-8533 (Japan); Koji Okamoto [University of Tokyo (Japan); Kaichiro Mishima [Research Reactor Institute, Kyoto University, Kumatori-cho, Sennan-gun, Osaka 590-0494 (Japan)

2002-07-01

102

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

Microsoft Academic Search

Abstract Abstract Abstract Abstract 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

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

103

Towards high efficiency thin-film crystalline silicon solar cells: The roles of light trapping and non-radiative recombinations  

NASA Astrophysics Data System (ADS)

Thin-film solar cells based on silicon have emerged as an alternative to standard thick wafers technology, but they are less efficient, because of incomplete absorption of sunlight, and non-radiative recombinations. In this paper, we focus on the case of crystalline silicon (c-Si) devices, and we present a full analytic electro-optical model for p-n junction solar cells with Lambertian light trapping. This model is validated against numerical solutions of the drift-diffusion equations. We use this model to investigate the interplay between light trapping, and bulk and surface recombination. Special attention is paid to surface recombination processes, which become more important in thinner devices. These effects are further amplified due to the textures required for light trapping, which lead to increased surface area. We show that c-Si solar cells with thickness of a few microns can overcome 20% efficiency and outperform bulk ones when light trapping is implemented. The optimal device thickness in presence of light trapping, bulk and surface recombination, is quantified to be in the range of 10-80 ?m, depending on the bulk quality. These results hold, provided the effective surface recombination is kept below a critical level of the order of 100 cm/s. We discuss the possibility of meeting this requirement, in the context of state-of-the-art techniques for light trapping and surface passivation. We show that our predictions are within the capability of present day silicon technologies.

Bozzola, A.; Kowalczewski, P.; Andreani, L. C.

2014-03-01

104

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

PubMed

Photoluminescence (PL) spectroscopy performed on arrays of semiconductor nanowires (NWs) suffers from ensemble broadening of PL lines, and fails to separate the PL from NWs of different crystal structures in the ensemble. Even the results on PL from single NWs are not devoid of ambiguity. This is because the influence of structural defects in NWs, such as stacking faults, twin boundaries and dislocations, on their optical spectra cannot be accounted for since the structural characteristics of the same NW remain largely unknown. We performed low-temperature PL spectroscopy on individual wurtzite (WZ) ZnSe NWs, and confirmed a homogeneous single-crystalline microstructure without any extended defects in these NWs, thus excluding any role of structural imperfections in their optical spectra. The luminescence is shown to be dominated solely by native point defects, while no role of extrinsic impurities was found. The radiative recombination is shown to originate from excitons bound to vacancies of Zn (VZn), VZn-complexes, and their phonon replicas. The binding energies of the acceptor-bound excitons, ionization energies of the acceptors, and average number of phonons emitted for shallow donor-VZn acceptor pair related transition were determined. Distinct from previous studies on PL from arrays of ZnSe NWs, this work provides an unambiguous interpretation of the PL spectra and assignment of PL peaks to WZ ZnSe. Narrow excitonic emission of linewidths 2.9 meV indicate excellent optical quality of WZ ZnSe NWs. PMID:23446447

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

2013-04-01

105

Topological phase transition in a topological crystalline insulator induced by finite-size effects  

NASA Astrophysics Data System (ADS)

We study electronic states and topological invariants of (001) films of the topological crystalline insulator (TCI) PbxSn1-xTe. Gapless surface Dirac cones on bulk TCIs become gapped in thin films due to the finite-size effect, which is the hybridization between the states on the top and bottom surfaces. We clarify that the TCI film has a strong finite-size effect as compared to three-dimensional topological insulators such as Bi2Se3. Moreover, the energy gap oscillates with the thickness of film. The oscillation stems from topological phase transitions in two dimensions. The obtained data of the topological invariants and energy gap serve as guide to TCI-device applications.

Ozawa, Hideyuki; Yamakage, Ai; Sato, Masatoshi; Tanaka, Yukio

2014-07-01

106

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

PubMed

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

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

2014-03-01

107

Treatment of radiation-induced cystitis with hyperbaric oxygen  

SciTech Connect

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.

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

1985-08-01

108

Radiation induces senescence and a bystander effect through metabolic alterations.  

PubMed

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

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

2014-01-01

109

Swelling characteristics of konjac glucomannan superabsobent synthesized by radiation-induced graft copolymerization  

NASA Astrophysics Data System (ADS)

Graft copolymerization of konjac glucomannan (KGM) and acrylic acid was induced by 60Co-? irradiation at room temperature. The effects of radiation dose and monomer-to-KGM ratio on grafting yield and equilibrium water absorbency were investigated. The KGM-based superabsorbent polymer (KSAP) could absorb water 625 times of its dry weight when the radiation dose was 5.0 kGy and monomer-to-KGM ratio was 5. The structure of KSAP was characterized by FTIR, XRD, and SEM. KSAP showed a lower crystallinity than KGM. The porous microstructure of KSAP was revealed by SEM. The diffusion mechanism of water in the hydrogel is consistent with the anomalous diffusion model. Cations, especially multivalent cations, greatly reduced water absorbency of KSAP. Rising temperature, acidic or basic solutions are not favorable for the swelling of KSAP.

Wu, Jia; Deng, Xiao; Lin, Xiangyang

2013-02-01

110

New principles of radiation damage and recovery based on the radiation induced emission of Schottky defects  

Microsoft Academic Search

New concept of radiation-induced emission of Schottky defects from extended defects is proposed, which acts in the opposite direction compared with Frenkel pair production, and it results in the radiation-induced recovery processes. The vacancy emission from a void surface results in a shrinkage of the void which is analogous to the thermal void shrinkage at high temperatures, but it is

Vladimir I. Dubinko

2002-01-01

111

Epigenetic Regulation of ?A-crystallin in High Myopia-Induced Dark Nuclear Cataract  

PubMed Central

Purpose To assess the etiology of early-onset dark nucleus in high-myopic patients and its relationship with the epigenetic regulation of ?A-crystallin (CRYAA). Methods We reviewed clinical data from patients who underwent cataract surgery at our center in 2012. Lens epithelial samples were collected during capsulorhexis, whereas young lens epithelium was donated. Cataract type and severity were graded according to the Lens Opacity Classification System III (LOCS III). DNA methylation was analyzed by pyrosequencing the CpG islands of the CRYAA promoter in the following groups: Age-Related Cataract (ARC) Nuclear Color (NC) 2–3; High-Myopic Cataract (HMC) NC2–3; ARC NC5–6; HMC NC5–6; and in young lenses graded NC1. We analyzed CRYAA expression by real-time polymerase chain reaction (PCR), reverse transcription PCR, and immunohistochemistry. Results The odds ratio of dark nucleus in high-myopic patients was 5.16 (95% confidence interval: 3.98–6.69; p<0.001). CpG islands in lens epithelial CRYAA promoter in the HMC NC5–6 Group exhibited the highest methylation of all the groups, but no statistically significant differences were evident between the HMC NC2–3 and ARC NC2–3 Groups. Likewise, CRYAA mRNA and protein levels in the HMC NC5–6 Group were significantly lower than the ARC NC5–6 Group and high-myopic controls. Conclusions High myopia is a risk factor for dark nucleus. Downregulation of CRYAA via the hypermethylation of CpG islands in its promoter could underlie the earlier onset of dark nucleus in high-myopic patients. PMID:24312600

Zhang, Ke-Ke; Yang, Jin; Luo, Yi; Lu, Yi

2013-01-01

112

Radiation-Induced Cavernomas of the Brain  

Microsoft Academic Search

Summary: The purpose of this report is to add support to the growing literature that there is a correlation between radiation and cavernomas of the brain, particularly if the radiation is received in childhood, as well as to increase awareness of this correlation in the radiology community. Retrospective review of our experience returned five pa- tients who received radiation therapy

Rajan Jain; Patricia L. Robertson; Dheeraj Gandhi; Sachin K. Gujar; Karin M. Muraszko; Stephen Gebarski

113

The influence of crystallinity degree on the glycine decomposition induced by 1 MeV proton bombardment in space analog conditions.  

PubMed

Glycine is the simplest proteinaceous amino acid and is present in all life-forms on Earth. In aqueous solutions, it appears mainly as zwitterion glycine (+NH3CH2COO-); however, in solid phase, it may be found in amorphous or crystalline (?, ?, and ?) forms. The crystalline forms differ from each other by the packing of zwitterions in the unitary cells and by the number of intermolecular hydrogen bonds. This molecular species has been extensively detected in carbonaceous meteorites and was recently observed in the cometary samples returned to Earth by NASA's Stardust spacecraft. In space, glycine is exposed to several radiation fields at different temperatures. We present an experimental study on the destruction of zwitterionic glycine crystals at room temperature by 1 MeV protons, in which the dependence of the destruction rates of the ?-glycine and ?-glycine crystals on bombardment fluence is investigated. The samples were analyzed in situ by Fourier transform infrared spectrometry at different proton fluences. The experiments occurred under ultrahigh vacuum conditions at the Van de Graaff accelerator lab at the Pontifical Catholic University at Rio de Janeiro (PUC-Rio), Brazil. For low fluences, the dissociation cross section of ?-glycine was observed to be 2.5×10(-14) cm2, a value roughly 5 times higher than the dissociation cross section found for ?-glycine. The estimated half-lives of ?-glycine and ?-glycine zwitterionic forms extrapolated to the Earth orbit environment are 9×10(5) and 4×10(6) years, respectively. In the diffuse interstellar medium the estimated values are 1 order of magnitude lower. These results suggest that pristine interstellar ?-glycine is the one most likely to survive the hostile environments of space radiation. A small feature around 1650-1700?cm(-1), tentatively attributed to an amide functional group, was observed in the IR spectra of irradiated samples, suggesting that cosmic rays may induce peptide bond synthesis in glycine crystals. Combining this finding with the fact that this form has the highest solubility among the other glycine polymorphs, we suggest that ?-glycine is the one most likely to have produced the first peptides on primitive Earth. PMID:23249407

Pilling, Sergio; Mendes, Luiz A V; Bordalo, Vinicius; Guaman, Christian F M; Ponciano, Cássia R; da Silveira, Enio F

2013-01-01

114

Formation and annihilation of intrinsic defects induced by electronic excitation in high-purity crystalline SiO{sub 2}  

SciTech Connect

Formation and thermal annihilation of intrinsic defects in {alpha}-quartz were examined using high-purity samples, while minimizing the contributions of reactions involving metallic impurities. Electronic excitation with {sup 60}Co {gamma}-rays was employed to avoid radiation-induced amorphization. The results clearly show that formation of oxygen vacancies (Si-Si bonds) as a result of decomposition of regular Si-O-Si bonds (Frenkel process) is the dominant intrinsic defect process. Compared with amorphous SiO{sub 2}, in {alpha}-quartz, the formation yield of Si-Si bonds is an order of magnitude smaller, the 7.6 eV optical absorption band is less broadened, and their thermal annihilation is complete at a lower temperature, around the {alpha}-{beta} quartz transition. In contrast, radiation-induced interstitial oxygen atoms practically do not form interstitial oxygen molecules.

Kajihara, Koichi [Department of Applied Chemistry, Graduate School of Urban Environmental Sciences, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji 192-0397 (Japan); Skuja, Linards [Institute of Solid State Physics, University of Latvia, Kengaraga iela 8, LV1063 Riga (Latvia); Hosono, Hideo [Materials and Structures Laboratory and Frontier Research Center, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503 (Japan)

2013-04-14

115

Coherent Cherenkov radiation from cosmic-ray-induced air showers.  

PubMed

Very energetic cosmic rays entering the atmosphere of Earth will create a plasma cloud moving with almost the speed of light. The magnetic field of Earth induces an electric current in this cloud which is responsible for the emission of coherent electromagnetic radiation. We propose to search for a new effect: Because of the index of refraction of air, this radiation is collimated in a Cherenkov cone. To express the difference from usual Cherenkov radiation, i.e., the emission from a fast-moving electric charge, we call this magnetically induced Cherenkov radiation. We indicate its signature and possible experimental verification. PMID:21902308

de Vries, K D; van den Berg, A M; Scholten, O; Werner, K

2011-08-01

116

Effect of radiation induced crosslinking and degradation of ETFE films  

NASA Astrophysics Data System (ADS)

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

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

2013-03-01

117

Theory of light-induced deformation of azobenzene elastomers: effects of the liquid-crystalline interactions and biaxiality.  

PubMed

We study light-induced deformation of azobenzene elastomers which can display liquid-crystalline (LC) order. It is shown that photomechanical behavior of azobenzene elastomers is determined by the strength of the LC interactions, which is proportional to the density of rodlike azobenzene chromophores. At weak LC interactions, a uniaxial order and uniaxial deformation of azobenzene elastomers along the polarization vector of the light E is observed. At strong LC interactions, the light is able to induce a phase transition from the uniaxial to the biaxial state, with two axes being related to the vector E and to a preferable alignment of the chromophores in the plane perpendicular to E. The phase transition can be of either the first or the second order. Azobenzene elastomers can demonstrate elongation or contraction along the polarization vector E, depending on the orientation distribution of chromophores around the main chains of network strands. The results of the theory are in a qualitative agreement with experiments and computer simulations, which demonstrate biaxial ordering in azo-containing polymers. PMID:25254355

Toshchevikov, Vladimir; Saphiannikova, Marina

2014-10-23

118

On the pressure-induced loss of crystallinity in orthophosphates of zinc and calcium  

Microsoft Academic Search

A recently suggested mechanism for the stress memory of various metal phosphates is investigated experimentally. Based on first-principles simulations [N. J. Mosey et al., Science 307, 1612 (2005)], it had been argued that atoms with flexible coordination, such as zinc or heavy-metal cations, act as network-forming agents, undergoing irreversible pressure-induced changes in bonding that lead to increased connectivity between phosphate

Dmitry Shakhvorostov; Martin H. Müser; Nicholas J. Mosey; David J. Munoz-Paniagua; Gavin Pereira; Yang Song; Masoud Kasrai; Peter R. Norton

2008-01-01

119

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

Microsoft Academic Search

A recently suggested mechanism for the stress memory of various metal phosphates is investigated experimentally. Based on first-principles simulations [N. J. Mosey et al., Science 307, 1612 (2005)], it had been argued that atoms with flexible coordination, such as zinc or heavy-metal cations, act as network-forming agents, undergoing irreversible pressure-induced changes in bonding that lead to increased connectivity between phosphate

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

2008-01-01

120

Features of thermomechanical properties of radiation-modified blends of high-density polyethylene with liquid-crystalline copolyester  

Microsoft Academic Search

The present paper surveys the investigation results of gamma-irradiated blends of high-density polyethylene (PE) with thermotropic liquid-crystalline polymer (LCP). The LCP used was a liquid crystalline copolyester of 40% poly(ethyleneterephthalate) with 60% p-(hydroxybenzoic acid). The LCP content in the blends was 0,5, and 10 wt.%. The constituents were blended with the use of a single-screw extruder. The samples were prepared

V. Kalkis; M. Kalninš; R. D. Maksimov; J. Zicans

1998-01-01

121

Electromechanical actuation and current-induced metastable states in suspended single-crystalline VO2 nanoplatelets  

SciTech Connect

Current-induced electromechanical actuation enabled by the metal-insulator transition in VO{sub 2} nanoplatelets is demonstrated. The Joule heating by a sufficient current flowing through suspended nanoplatelets results in formation of heterophase domain patterns and is accompanied by nanoplatelet deformation. The actuation action can be achieved in a wide temperature range below the bulk phase transition temperature (68 C). The observed current-sustained heterophase domain structures should be interpreted as distinct metastable states in free-standing and end-clamped VO{sub 2} samples. We analyze the main prerequisites for the realization of a current-controlled actuator based on the proposed concept.

Tselev, Alexander [ORNL; Budai, John D [ORNL; Strelcov, Evgheni [Southern Illinois University; Tischler, Jonathan Zachary [ORNL; Kolmakov, Andrei [Southern Illinois University; Kalinin, Sergei V [ORNL

2011-01-01

122

Light induced enhancement of minority carrier lifetime of chemically passivated crystalline silicon  

NASA Astrophysics Data System (ADS)

In this work we present light effects on chemically passivated silicon surface. Di-iodine-ethanol (I-E) mixtures were used to passivate silicon dangling bonds. The passivation quality is sensitive to both silicon surface state and light irradiation. The minority carrier lifetime values vary from 2 ?s for unpassivated surfaces to about 40 ?s for chemically passivated ones. FTIR investigations show that light irradiation catalyses the passivation effect by forming the silicon-ethoxylate group (sbnd Sisbnd Osbnd C2H5). We suggest a mechanism to explain the passivation effect based on carrier-induced dissociation of I2.

Aouida, S.; Bachtouli, N.; Bessais, B.

2013-06-01

123

Heavy-ion radiation induced bystander effect in mice  

NASA Astrophysics Data System (ADS)

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.

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

2012-07-01

124

Radiation-induced myeloid leukemia in murine models.  

PubMed

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

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

2014-01-01

125

Radiation-induced myeloid leukemia in murine models  

PubMed Central

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

2014-01-01

126

Hyperbaric Oxygen Therapy for Radiation-induced Optic Neuropathy  

Microsoft Academic Search

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

Richard L Levy; Neil R Miller

127

Morphology and pathology of radiation-induced esophagitis  

Microsoft Academic Search

Radiation-induced esophagitis can cause substantial morbidity. Experiments in lab animals have shown that pretreatment with indomethacin protects the esophagus from radiation damage. We conducted a prospective, double-blind, randomized trial of naproxen vs placebo in patients undergoing thoracic radiation therapy for lung cancer. Twenty-eight patients were enrolled, of which 26 completed the study. Sixteen patients were given a short course of

Edy E. Soffer; Frank Mitros; J. Fred Doornbos; Jay Friedland; Janice Launspach; Robert W. Summers

1994-01-01

128

Coherent microwave radiation from a laser induced plasma  

SciTech Connect

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.

Shneider, M. N.; Miles, R. B. [Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544-5263 (United States)

2012-12-24

129

Radiation-induced apoptosis in the eye structures: a review  

NASA Astrophysics Data System (ADS)

Apoptosis plays a crucial role in tissue homeostasis and in the removal of damaged cells from tissues. Both increased and insufficient cell death can lead to human diseases. Apoptotic process is under the control of physiological metabolism as well as a panel of genes. After exposure to radiation, membrane damages induce the membrane pathway signal transduction for cell apoptosis. The importance of the radiation-induced apoptosis in the different ocular tissues and its relationship to the radiation parameters are reviewed in this article. This topic of ocular research has not been addressed in detail in the literature.

Belkacémi, Yazid; Huchet, Aymeri; Baudouin, Christophe; Lartigau, Éric

2005-02-01

130

Pressure- and temperature-induced transformations in crystalline polymers of C{sub 60}  

SciTech Connect

The great advantage of the C{sub 60} molecule is its potential for polymerization, due to which the molecule can be the building block of new all carbon materials. In addition, it contains, both sp{sup 2} and sp{sup 3} hybridized carbon atoms, which allows synthesizing new carbon materials with desired physicochemical properties using both types of carbon bonding. The one- and two-dimensional polymeric phases of C{sub 60} are prototype materials of this sort. Their properties, especially polymerization under pressure and room temperature via covalent bonding between molecules belonging to adjacent polymeric chains or polymeric layers, can be used for further development of new materials. The present review focuses on the study of the pressure-induced polymerization and thermodynamic stability of these materials and their recovered new phases by in-situ high-pressure Raman and X-ray diffraction studies. The phonon spectra show that the fullerene molecular cage in the high-pressure phases is preserved, while these polymers decompose under heat treatment into the initial fullerene C{sub 60} monomer.

Meletov, K. P., E-mail: mele@issp.ac.ru [Russian Academy of Sciences, Institute of Solid State Physics (Russian Federation); Kourouklis, G. A. [Aristotle University of Thessaloniki GR-54006, Physics Division, School of Technology (Greece)

2012-10-15

131

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

NASA Astrophysics Data System (ADS)

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

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

2007-10-01

132

Halofuginone Mediated Protection against Radiation-Induced Leg Contracture  

PubMed Central

Fibrosis of normal tissues often accompanies radiation treatment of cancer. Activation of the transforming growth factor-? (TGF-?) signaling pathway is thought to play a major role in radiation-induced fibrosis and has prompted the development and assessment of low molecular weight inhibitors of the pathway. Previous studies with halofuginone have shown it to inhibit TGF-? signaling in vitro and protect mice from radiation-induced leg contraction (a model for soft tissue fibrosis). The current study confirms these findings for HaCaT cells stimulated with exogenous TGF-? treatment. Reducing the halifuginone treatment from 7 days/week (used previously) to 5 days/week post-radiation exposure provided significant protection against radiation-induced leg contraction in mice 3 and 4 months post-radiation treatment. Halofuginone treatment was shown to attenuate TGF-? signaling molecules taken from irradiated skin including TGF-?RII, pSmad3, Smad7, and TSP1. The latter, TSP1, a co-activator of TGF-? may serve as a suitable biomarker for monitoring the efficacy of halofuginone should it be evaluated in a clinical setting for protection against radiation-induced fibrosis. PMID:19578745

Ishii, Hisanari; Choudhuri, Rajani; Mathias, Askale; Sowers, Anastasia L.; Flanders, Kathleen C.; Cook, John A.; Mitchell, James B.

2012-01-01

133

Radiation-induced coronary artery disease  

SciTech Connect

This report describes three patients who developed myocardial infarction at an untimely age, 4 to 12 years after radiation therapy for Hodgkin's disease. These cases lend credence to the cause and effect relation of such therapy to coronary artery disease.

Dunsmore, L.D.; LoPonte, M.A.; Dunsmore, R.A.

1986-07-01

134

Non-targeted bystander effects induced by ionizing radiation.  

PubMed

Radiation-induced bystander effects refer to those responses occurring in cells that were not subject to energy deposition events following ionizing radiation. These bystander cells may have been neighbors of irradiated cells, or physically separated but subject to soluble secreted signals from irradiated cells. Bystander effects have been observed in vitro and in vivo and for various radiation qualities. In tribute to an old friend and colleague, Anthony V. Carrano, who would have said "well what are the critical questions that should be addressed, and so what?", we review the evidence for non-targeted radiation-induced bystander effects with emphasis on prevailing questions in this rapidly developing research field, and the potential significance of bystander effects in evaluating the detrimental health effects of radiation exposure. PMID:17134726

Morgan, William F; Sowa, Marianne B

2007-03-01

135

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

PubMed

Offering mild, non-invasive and deep cancer therapy modality, radio frequency (RF) radiation-induced hyperthermia lacks for efficient biodegradable RF sensitizers to selectively target cancer cells and thus avoid side effects. Here, we assess crystalline silicon (Si) based nanomaterials as sensitizers for the RF-induced therapy. Using nanoparticles produced by mechanical grinding of porous silicon and ultraclean laser-ablative synthesis, we report efficient RF-induced heating of aqueous suspensions of the nanoparticles to temperatures above 45-50°C under relatively low nanoparticle concentrations (<1?mg/mL) and RF radiation intensities (1-5?W/cm(2)). For both types of nanoparticles the heating rate was linearly dependent on nanoparticle concentration, while laser-ablated nanoparticles demonstrated a remarkably higher heating rate than porous silicon-based ones for the whole range of the used concentrations from 0.01 to 0.4?mg/mL. The observed effect is explained by the Joule heating due to the generation of electrical currents at the nanoparticle/water interface. Profiting from the nanoparticle-based hyperthermia, we demonstrate an efficient treatment of Lewis lung carcinoma in vivo. Combined with the possibility of involvement of parallel imaging and treatment channels based on unique optical properties of Si-based nanomaterials, the proposed method promises a new landmark in the development of new modalities for mild cancer therapy. PMID:25391603

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

2014-01-01

136

Hematopoiesis research in aplastic anaemia induced by accidental protracted radiation.  

PubMed

Over the past few years there have been 2 radiation-related accidents involving a large number of individuals: the April 1986 accident in Chernobyl nuclear power station in the Ukraine and the September 1987 accident in Goiania, Brazil. These 2 radiation-related accidents highlight the major question raised by radiation-induced injury to the haematopoietic system, that is: does a given patient suffer from a reversible or an irreversible haematopoietic stem cell damage? Although about 350 radiation accidents involving several thousand people are known from the literature, in-depth haematopoiesis analyses of individuals after a radiation-related accident have rarely been reported. In this paper we present the case of a young man with radiation-induced aplasia and compare some biological data to those of 16 normal individuals and of 17 patients with acquired aplastic anaemia. Our patient was clinically and biologically (as assessed by long-term bone marrow culture) indistinguishable from patients with idiopathic acquired aplastic anaemia. Furthermore, therapeutic attitudes in this patient are discussed. In-depth study of such radiation-induced aplastic anaemia cases can shed some light in the understanding of this disease and may help in therapeutic decisions. PMID:8949395

Socié, G; Medhi Sohrabi, K; Carosella, E D; Cosset, J M; Hervatin, F; de Cremoux, P; Dutrillaux, B; Sheibani, K M; Rabian, C; Gourmelon, P; Parmentier, C; Gluckman, E

1996-08-01

137

Hyperprolactinemia from radiation-induced hypothalamic hypopituitarism  

SciTech Connect

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.

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

1980-01-01

138

Dynamics of plasma formation, relaxation, and topography modification induced by femtosecond laser pulses in crystalline and amorphous dielectrics  

SciTech Connect

We have studied plasma formation and relaxation dynamics along with the corresponding topography modifications in fused silica and sapphire induced by single femtosecond laser pulses (800 nm and 120 fs). These materials, representative of high bandgap amorphous and crystalline dielectrics, respectively, require nonlinear mechanisms to absorb the laser light. The study employed a femtosecond time-resolved microscopy technique that allows obtaining reflectivity and transmission images of the material surface at well-defined temporal delays after the arrival of the pump pulse which excites the dielectric material. The transient evolution of the free-electron plasma formed can be followed by combining the time-resolved optical data with a Drude model to estimate transient electron densities and skin depths. The temporal evolution of the optical properties is very similar in both materials within the first few hundred picoseconds, including the formation of a high reflectivity ring at about 7 ps. In contrast, at longer delays (100 ps-20 ns) the behavior of both materials differs significantly, revealing a longer lasting ablation process in sapphire. Moreover, transient images of sapphire show a concentric ring pattern surrounding the ablation crater, which is not observed in fused silica. We attribute this phenomenon to optical diffraction at a transient elevation of the ejected molten material at the crater border. On the other hand, the final topography of the ablation crater is radically different for each material. While in fused silica a relatively smooth crater with two distinct regimes is observed, sapphire shows much steeper crater walls, surrounded by a weak depression along with cracks in the material surface. These differences are explained in terms of the most relevant thermal and mechanical properties of the material. Despite these differences the maximum crater depth is comparable in both material at the highest fluences used (16 J/cm{sup 2}). The evolution of the crater depth as a function of fluence can be described taking into account the individual bandgap of each material.

Puerto, D.; Siegel, J.; Gawelda, W.; Galvan-Sosa, M.; Solis, J. [Laser Processing Group, Instituto de Optica-CSIC, Madrid (Spain); Ehrentraut, L. [Max-Born-Institut fuer Nichtlineare Optik und Kurzzeitspektroskopie, Berlin (Germany); Bonse, J. [Bundesanstalt fuer Materialforschung und-pruefung (BAM), Berlin (Germany)

2010-05-15

139

Radiation induced growth of micro crystallites  

SciTech Connect

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.

Meisel, D.

1991-01-01

140

Radiation recall dermatitis induced by trastuzumab.  

PubMed

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

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

2013-03-31

141

Process and Radiation Induced Defects in Electronic Materials and Devices  

NASA Technical Reports Server (NTRS)

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.

Washington, Kenneth; Fogarty, T. N.

1997-01-01

142

Penetration of microwave radiation into water: Effect of induced transparency  

Microsoft Academic Search

The propagation of intense microwave radiation in a water column is studied experimentally. The effect of induced transparency\\u000a of water is discovered. The effect is related to the successive heating of water layers from the surface deep into the water\\u000a column. The interaction of intense microwave radiation with water is simulated with account of variations in the electrophysical\\u000a water parameters.

V. Yu. Knyazev; I. A. Kossyi; N. I. Malykh; E. S. Yampolskii

2003-01-01

143

Pulsed radiation-induced attenuation in certain optical fibers  

Microsoft Academic Search

Using the X-ray pulse from the HERMES II simulation machine at Sandia National Laboratories, the pulsed radiation-induced attenuation was measured in two optical fibers considered to be 'nonrad-hard': the 50-micron-core, graded-index fiber from Corning and the plastic (PMMA) fiber from the Mitsubishi Rayon Company. These fibers were exposed to radiation up to doses of 19.5 and 28 krad(Si), respectively. In

Jonathan D. Weiss

1992-01-01

144

Pulsed radiation-induced attenuation in certain optical fibers  

Microsoft Academic Search

Using the X-ray pulse from the HERMES II simulation machine at Sandia National Laboratories, the author measured the pulsed radiation-induced attenuation in two optical fibers considered to be `non-rad-hard': the 50 ?m core graded-index fiber from Corning and the plastic (PMMA) fiber from the Mitsubishi Rayon Company. These fibers were exposed to radiation up to doses of 19.5 and 28

J. D. Weiss

1992-01-01

145

The radiation induced degradation of polymers  

NASA Astrophysics Data System (ADS)

A compilation was made of all data about the radiation stability of thermoplastic polymeric materials, published in the literature up to the end of 1985. From those experiments in which the irradiation was carried out in air half value doses (elongation) ( = hvd) as a measure of radiation stability were extracted and compared on the basis of the chemical structure of the polymers, the chemical composition of the materials under test and the dose rate, respectively. The first result is that our knowledge of the radiation stability of polymers, if irradiated in air, is still very incomplete. On the other hand enough data were found for some polymers, to see that there is a region at low dose rates where the half value dose De increases with the dose rate D? according to the equation De = De1 · D? n. This seems to be the normal behavior. Values for the hvd at 1 Gy/h (in air) were found to lie between 1 and 500 kGy (with PTFE and PS at the respective ends of the scale), whereas n varied only between 0.1 and 0.4. The range of validity of the equation and the magnitude of the coefficients strongly depend on the chemical nature of the polymer and also on the kind and amount of the additives used. At dose rates in the neighborhood of 10 5 Gy/h the influence of the dose rate (and the atmosphere) disappears.

Wilski, Hans

146

Radiation-induced nonlinear optical response of quartz fibers  

NASA Astrophysics Data System (ADS)

The intensity of radiation-induced luminescence and transient optical losses in KU-1 (Russia) and K-3 (Japan) quartz glass optical tibers irradiated in a fast pulsed fission reactor (a pulse duration of 80 ?s and a neutron flux up to 7 × 1016 cm 2 s 2) has been measured in the visible range. The intensity of the fast luminescence component nonlinearly depends on the neutron flux. The luminescence intensity and the transient optical losses depend on the probe light intensity. Suppression of radiation-induced luminescence is observed at wavelengths that are longer or shorter than the probe light wavelength. Light probing leads to an increase in transient optical losses and a more rapid recovery of transparency. A model of two photon fluxes is proposed to analyze the relationship of the effects of suppression of radiation-induced luminescence and the increase in optical losses upon light probing. The effect of suppression of radiation-induced luminescence can be used to control the optical properties of fibers in radiation fields.

Plaksin, O. A.

2006-10-01

147

Simvastatin attenuates radiation-induced tissue damage in mice  

PubMed Central

The aim of this study was to investigate the protective effect of simvastatin against radiation-induced tissue injury in mice. Mice were radiated with 4 Gy or 8 Gy after 20 mg/kg/d simvastatin treatment over 2 weeks. Morphological changes were observed in the jejunum and bone marrow, and apoptotic cells were determined in both tissues. Peripheral blood cells were counted, and the superoxide dismutase (SOD) activity and the malondialdehyde (MDA) level in tissues of both thymus and spleen were measured. Compared with the radiation-only group, 20 mg/kg/d simvastatin administration significantly increased the mean villi height and decreased apoptotic cells in jejunum tissue, and stimulated regeneration and reduced apoptotic cells in bone marrow. Peripheral blood cell analysis revealed that simvastatin treatment induced a larger number of red blood cells and increased the hemoglobin level present after 4 Gy of radiation. Interestingly, it was also found that the number of peripheral endothelial progenitor cells was markedly increased following simvastatin administration. Antioxidant determination for tissues displayed that simvastatin therapy increased the SOD activity after both 4 and 8 Gy of radiation, but only decreased the MDA level after 4 Gy. Simvastatin ameliorated radiation-induced tissue damage in mice. The radioprotective effect of simvastatin was possibly related to inhibition of apoptosis and improvement of oxygen-carrying and antioxidant activities. PMID:24105712

Zhao, Xinbin; Yang, Hong; Jiang, Guojun; Ni, Min; Deng, Yaping; Cai, Jian; Li, Zhangpeng; Shen, Fuming; Tao, Xia

2014-01-01

148

Radiation-induced products of peptides and their enzymatic digestibility  

SciTech Connect

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.

Gajewski, E.

1983-01-01

149

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

NASA Astrophysics Data System (ADS)

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

Matsumoto, H.; Ohnishi, T.

150

Irradiated Esophageal Cells are Protected from Radiation-Induced Recombination by MnSOD Gene Therapy  

E-print Network

Irradiated Esophageal Cells are Protected from Radiation-Induced Recombination by MnSOD Gene. Irradiated Esophageal Cells are Protected from Radiation- Induced Recombination by MnSOD Gene Therapy. Radiat in esophageal cells. These results demonstrate the efficacy of MnSOD-PL for suppressing radiation-induced HR

Engelward, Bevin

151

Mechanisms of radiation-induced neoplastic cell transformation  

SciTech Connect

Studies with cultured mammalian cells demonstrated clearly that radiation can transform cells directly and can enhance the cell transformation by oncogenic DNA viruses. In general, high-LET heavy-ion radiation can be more effective than X and gamma rays in inducing neoplastic cell transformation. Various experimental results indicate that radiation-induced DNA damage, most likely double-strand breaks, is important for both the initiation of cell transformation and for the enhancement of viral transformation. Some of the transformation and enhancement lesions can be repaired properly in the cell, and the amount of irrepairable lesions produced by a given dose depends on the quality of radiation. An inhibition of repair processes with chemical agents can increase the transformation frequency of cells exposed to radiation and/or oncogenic viruses, suggesting that repair mechanisms may play an important role in the radiation transformation. The progression of radiation-transformed cells appears to be a long and complicated process that can be modulated by some nonmutagenic chemical agents, e.g., DMSO. Normal cells can inhibit the expression of transforming properties of tumorigenic cells through an as yet unknown mechanism. The progression and expression of transformation may involve some epigenetic changes in the irradiated cells. 38 references, 15 figures, 1 table.

Yang, T.C.H.; Tobias, C.A.

1984-04-01

152

Chemoprevention of Radiation Induced Rat Mammary Neoplasms  

NASA Technical Reports Server (NTRS)

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

Huso, David L.

1999-01-01

153

Radiation Induced DNA-Damage\\/Repair and Associated Signaling Pathways  

Microsoft Academic Search

Radiation-induced DNA damage and related repair mechanisms are described in this chapter. The emerging connection with growth\\u000a factor induced signal transduction is described, with important implications for radiotherapy. The prospect of developing\\u000a targeting agents, which selectively deliver radioactivity to the tumor and at the same time radiosensitize the tumor cells\\u000a is discussed in some detail.

Bo Stenerlöw; Lina Ekerljung; Jörgen Carlsson; Johan Lennartsson

154

Radiation-induced endometriosis in Macaca mulatta  

SciTech Connect

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

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

1991-05-01

155

Stimulation of respiration in rat thymocytes induced by ionizing radiation  

SciTech Connect

The effect of X irradiation on the respiration of rat thymocytes was studied. An increase in the rate of O[sub 2] uptake was observed 1 h after cells were irradiated with doses of 6-10 Gy. The radiation-induced increase in respiration could be blocked by oligomycin, an inhibitor of mitochondrial ATP synthase, suggesting control by increased cytoplasmic ATP turnover. The stimulation of respiration was not associated with changes in the activity of mitochondrial electron transfer enzymes or permeability of the inner membrane. Several inhibitors of processes which used ATP were screened for their effects on the basal respiration rate and on the radiation response. In irradiated thymocytes, an enhancement of inhibition of respiration by ouabain, La[sup 3+] and cycloheximide was observed. These results indicate that the radiation-induced stimulation of respiration is due to changes in ion homeostasis and protein synthesis. The effect of X irradiation was shown to be independent of the redox status of nonprotein thiols and was not associated with detectable changes in some products of lipid peroxidation. The radiation-induced decrease in activity of superoxide dismutase suggests free radical involvement in deleterious effects of radiation. 43 refs., 2 figs., 3 tabs.

Gudz, T.I.; Pandelova, I.G.; Novgorodov, S.A. (Moscow State Univ. (Russian Federation))

1994-04-01

156

Plasma prostaglandin levels in radiation-induced enteritis  

Microsoft Academic Search

Increased prostaglandin synthesis has been implicated as a causative factor in the production of radiation induced enteritis. Seventeen patients selected to begin pelvic irradiation for treatment of gynecological cancer had plasma Prostaglandin E, Prostaglandin F, and 13, 14 dihydro 15 keto PGF\\/sub 2..cap alpha..\\/ metabolite determined by radioimmunoassay, prior to initiation of radiotherapy, at weekly intervals during treatment and at

Samuel Lifshitz; John E. Savage; Kevin A. Taylor; Hamed H. Tewfik; Dianna E. Van Orden

1982-01-01

157

Surface oscillations — A possible source of fracture induced electromagnetic radiation  

Microsoft Academic Search

Radio frequency electromagnetic radiation (EMR) registered hundreds of kilometres away from an earthquake epicentre is detected hours before earthquakes. Yet, accurate earthquakes prediction by their self-induced EMR still remains in its infancy due in part to the lack of understanding of EMR's origin. Here we present a viable model of this origin, according to which EMR is emitted by an

A. Rabinovitch; V. Frid; D. Bahat

2007-01-01

158

SPHINX Measurements of Radiation Induced Conductivity of Foam  

SciTech Connect

Experiments on the SPHINX accelerator studying radiation-induced conductivity (RIC) in foam indicate that a field-exclusion boundary layer model better describes foam than a Maxwell-Garnett model that treats the conducting gas bubbles in the foam as modifying the dielectric constant. In both cases, wall attachment effects could be important but were neglected.

Ballard, W.P.; Beutler, D.E.; Burt, M.; Dudley, K.J.; Stringer, T.A.

1998-12-14

159

Effect of sodium meclofenamate on ultraviolet radiation induced carcinogenesis  

SciTech Connect

Sodium meclofenamate (Meclomen), an antiprostaglandin antileukotriene agent, was found in previous studies to protect primates against x-ray induced brain edema, esophagitis and cystitis. In the present study, it appeared to protect hairless mice against the carcinogenic effect of ultraviolet B-radiation.

Ambrus, J.L.; Ambrus, C.M.; Pickren, J.W.; Klein, E.

1984-01-01

160

Cosmology for grand unified theories with radiatively induced symmetry breaking  

Microsoft Academic Search

The treatment of first-order phase transitions for standard grand unified theories is shown to break down for models with radiatively induced spontaneous symmetry breaking. It is argued that proper analysis of these transitions which would take place in the early history of the universe can lead to an explanation of the cosmological homogeneity, flatness, and monopole puzzles.

Andreas Albrecht; P. J. Steinhardt

1982-01-01

161

Radiation induced physical and chemical processes in zeolite materials  

Microsoft Academic Search

Ionic processes induced by high energy radiation in zeolites, including electron and hole trapping and related chemical reactions, are reviewed in this paper. Electronic structures of electrons localized in clusters of charge balancing cations and those solvated in zeolite confined water clusters are characterized by a combination of spectroscopic techniques such as ESR and transient UV–visible absorption. Reactivities of these

Guohong Zhang; Xinsheng Liu; J. Kerry Thomas

1997-01-01

162

SENSITIVITY TO RADIATION-INDUCED CANCER IN HEMOCHROMATOSIS  

EPA Science Inventory

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

163

Radiation-induced decomposition of explosives under extreme conditions  

SciTech Connect

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.

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

2008-11-03

164

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

PubMed

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

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

2010-02-01

165

Radiation-Induced Bystander Response: Mechanism and Clinical Implications  

PubMed Central

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

Suzuki, Keiji; Yamashita, Shunichi

2014-01-01

166

Countermeasures against space radiation induced oxidative stress in mice.  

PubMed

Of particular concern for the health of astronauts during space travel is radiation from protons and high atomic number (Z), high energy particles (HZE particles). Space radiation is known to induce oxidative stress in astronauts after extended space flight. In the present study, the total antioxidant status was used as a biomarker to evaluate oxidative stress induced by proton and HZE particle radiation in the plasma of CBA mice and the protective effect of dietary supplement agents. The results indicate that exposure to proton and HZE particle radiation significantly decreased the plasma level of total antioxidants in the irradiated CBA mice. Dietary supplementation with L: -selenomethionine (SeM) or a combination of selected antioxidant agents (which included SeM) could partially or completely prevent the decrease in the total antioxidant status in the plasma of animals exposed to proton or HZE particle radiation. These findings suggest that exposure to space radiation may compromise the capacity of the host antioxidant defense system; this adverse biological effect can be prevented at least partially by dietary supplementation with agents expected to have effects on antioxidant activities. PMID:17387501

Kennedy, A R; Guan, J; Ware, J H

2007-06-01

167

Radiation-induced genomic instability and its implications for radiation carcinogenesis  

NASA Technical Reports Server (NTRS)

Radiation-induced genomic instability is characterized by an increased rate of genetic alterations including cytogenetic rearrangements, mutations, gene amplifications, transformation and cell death in the progeny of irradiated cells multiple generations after the initial insult. Chromosomal rearrangements are the best-characterized end point of radiation-induced genomic instability, and many of the rearrangements described are similar to those found in human cancers. Chromosome breakage syndromes are defined by chromosome instability, and individuals with these diseases are cancer prone. Consequently, chromosomal instability as a phenotype may underlie some fraction of those changes leading to cancer. Here we attempt to relate current knowledge regarding radiation-induced chromosome instability with the emerging molecular information on the chromosome breakage syndromes. The goal is to understand how genetic and epigenetic factors might influence the onset of chromosome instability and the role of chromosomal instability in carcinogenesis.

Huang, Lei; Snyder, Andrew R.; Morgan, William F.

2003-01-01

168

Gene expression profiles for radiation-induced thyroid cancer.  

PubMed

The question whether radiation-induced thyroid cancer differs by its molecular biology from sporadic disease still remains. Studies on tissue from patients who developed thyroid cancer after the Chernobyl accident have provided a unique opportunity to look for biological consequences of low-dose irradiation by comparing the gene expression profile of sporadic papillary thyroid cancer (PTC), whose aetiology is unknown, and PTC induced by internal radiation. So far, four transcriptomic studies comparing radiation-induced and sporadic thyroid cancer have been reported. However, no final conclusion has been drawn regarding the presence of a radiation signature, as either no difference was noted or the reported differences were not sufficiently convincing due to the low number of cases analysed or to the presence of confounding factors. The list of putative biological and clinical factors that may influence the PTC gene expression profile is long, but there are sufficient data reported in the literature to link expression profiles with differing pathological variants of PTC. The comparison of expression profiles in the tumour samples allows the search for a radiation signature, whereas the comparison of expression profiles of the normal contralateral tissues offers a substantial opportunity for assessing the existence of a susceptibility to radiation that could be responsible for tumour development. We have undertaken this analysis as part of a European Union-funded project, GENRISK-T. Gene expression profiles were investigated in tumours that have arisen in the population exposed to fallout from Chernobyl (i.e. born before 26 April 1986) and were compared with profiles of tumours of similar pathology arising in an age-matched population, residing in the same geographical area (same ethnicity) and born after 1 January 1987. RNA samples from these tumours and their contralateral normal tissues were obtained from the Chernobyl Tissue Bank. Several lines of evidence suggest that the predisposition to developing cancer after radiation exposure is variable in the general population and may be measurable from gene expression. PMID:21411301

Maenhaut, C; Detours, V; Dom, G; Handkiewicz-Junak, D; Oczko-Wojciechowska, M; Jarzab, B

2011-05-01

169

Radiation-induced mesotheliomas in rats  

SciTech Connect

Mesotheliomas have been reported in rats that inhaled plutonium, but these tumors have not been extensively studied. To investigate a possible role for inhaled radionuclides in the induction of mesotheliomas, four life-span studies conducted at the Inhalation Toxicology Research Institute are reviewed. A total of 3076 F344 rats were exposed by inhalation to aerosols of {sup 239}PuO{sub 2}, mixed uranium-plutonium oxide, or {sup 144}CeO{sub 2}. Results showed that a low incidence of pleural mesotheliomas was induced by either alpha- or beta-emitting radionuclides deposited and retained in the lung. Chronic alpha irradiation was more effective per unit dose in producing mesotheliomas than chronic beta irradiation of the lung by a factor of 15. 7 refs., 1 tab., 7 figs. (MHB)

Hahn, F.F.; Haley, P.J.; Hubbs, A.F.; Hoover, M.D.; Lundgren, D.L.

1990-01-01

170

Radiation-induced swelling of stainless steel.  

PubMed

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

Shewmon, P G

1971-09-10

171

Radiation-induced DNA damage and chromatin structure  

NASA Technical Reports Server (NTRS)

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

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

2001-01-01

172

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

PubMed

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

Knüsli, Claudio; Walter, Martin

2013-12-01

173

Radiation-Induced Notch Signaling in Breast Cancer Stem Cells  

SciTech Connect

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

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

2013-11-01

174

Electron-beam induced terahertz radiation from graded metallic grating.  

PubMed

We have numerically analyzed, based on a simplified particle-in-cell finite-difference time-domain (PIC-FDTD) method, an electron-beam (e-beam) induced terahertz (THz) radiation from metallic grating structures with graded depths (graded grating). Upon exciting with e-beam, directional THz radiations with wide-band spectrum containing several sharp peaks are obtained only from the one of the edge of the grating, which cannot be expected from the conventional theory of Smith-Purcell radiation. It was clarified that each modes originate from different locations on the graded grating reflecting different dispersion characteristics of spoof surface plasmon polariton (spoof SPP) at each locations, and they can propagate toward only the shallower groove as a surface wave due to the cutoff at each locations, and all of these modes eventually emitted from the one of the edge of the graded grating. These directional radiations can be directed toward either backward or forward by making the groove depth deeper or shallower. The lowest and the highest frequency of the radiation can be chosen by appropriately designing the deepest and the shallowest groove depths, respectively. These unique radiations cannot be obtained from the uniformly grooved grating. Our findings may open the way for a development of novel THz radiation source based on the spoof SPP on the wide variety of metallic grating structures or metasurfaces. PMID:25090564

Okajima, Akiko; Matsui, Tatsunosuke

2014-07-14

175

Ionizing radiation-induced mutagenesis: radiation studies in Neurospora predictive for results in mammalian cells  

NASA Technical Reports Server (NTRS)

Ionizing radiation was the first mutagen discovered and was used to develop the first mutagenicity assay. In the ensuing 70+ years, ionizing radiation became a fundamental tool in understanding mutagenesis and is still a subject of intensive research. Frederick de Serres et al. developed and used the Neurospora crassa ad-3 system initially to explore the mutagenic effects of ionizing radiation. Using this system, de Serres et al. demonstrated the dependence of the frequency and spectra of mutations induced by ionizing radiation on the dose, dose rate, radiation quality, repair capabilities of the cells, and the target gene employed. This work in Neurospora predicted the subsequent observations of the mutagenic effects of ionizing radiation in mammalian cells. Modeled originally on the mouse specific-locus system developed by William L. Russell, the N. crassa ad-3 system developed by de Serres has itself served as a model for interpreting the results in subsequent systems in mammalian cells. This review describes the primary findings on the nature of ionizing radiation-induced mutagenesis in the N. crassa ad-3 system and the parallel observations made years later in mammalian cells.

Evans, H. H.; DeMarini, D. M.

1999-01-01

176

Chromosome aberrations induced by high-LET radiations  

NASA Technical Reports Server (NTRS)

Measurements of chromosome aberrations in peripheral blood lymphocytes are currently the most sensitive and reliable indicator of radiation exposure that can be used for biological dosimetry. This technique has been implemented recently to study radiation exposures incurred by astronauts during space flight, where a significant proportion of the dose is delivered by high-LET particle exposure. Traditional methods for the assessing of cytogenetic damage in mitotic cells collected at one time point after exposure may not be suitable for measuring high-LET radiation effects due to the drastic cell cycle perturbations and interphase cell death induced by this type of exposure. In this manuscript we review the recent advances in methodology used to study high-LET induced cytogenetic effects and evaluate the use of chemically-induced Premature Chromosome Condensation (PCC) as an alternative to metaphase analysis. Published data on the cytogenetic effects of in vitro exposures of high-LET radiation is reviewed, along with biodosimetry results from astronauts after short or long space missions.

Kawata, Tetsuya; Ito, Hisao; George, Kerry; Wu, Honglu; Cucinotta, Francis A.

2004-01-01

177

Radiation-induced optic neuropathy: A magnetic resonance imaging study  

SciTech Connect

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

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

1991-03-01

178

Inner-shell electron excitation effect on the structural change in amorphous and crystalline GaAs with brilliant X-ray irradiation using synchrotron radiation  

SciTech Connect

Amorphous layers of gallium arsenide (a-GaAs) formed by heavy implantation of silicon ions and crystalline gallium arsenide (c-GaAs) were irradiated with monochromatized X-rays using brilliant synchrotron radiation. Infrared absorption measurements at low temperature for a-GaAs specimens showed that X-rays having an energy larger than the K-binding energy of As atoms created a much larger fraction of Si-Ga and Si-As bondings than in the as-implanted state. On the other hand, from photoluminescence measurements, it was confirmed that X-rays having a smaller energy than either of the K binding energies, enhanced the relaxation of the a-GaAs network, and created some defects in c-Ga-As. The mechanism for these structural changes is discussed from the viewpoint of relaxation processes after inner-shell electron excitation by X-rays.

Sato, Fumio; Saito, Nobuo; Kusano, Junichi; Takizawa, Kuniharu [NHK Science and Technical Research Labs., Kinuta, Tokyo (Japan); Kawado, Seiji [Sony Corp. Research Center, Yokohama (Japan); Kato, Takanori [Sumitomo Heavy Industries, Ltd., Tanashi, Tokyo (Japan); Sugiyama, Hiroshi; Kagoshima, Yasushi; Ando, Masami [National Lab. for High Energy Physics, Tsukuba, Ibaraki (Japan)

1998-09-01

179

Modeling radiation-induced mixing at interfaces between low solubility metals  

E-print Network

This thesis studies radiation-induced mixing at interfaces between low solubility metals using molecular dynamics (MD) computer simulations. It provides original contributions on the fundamental mechanisms of radiation-induced ...

Zhang, Liang, Ph. D. Massachusetts Institute of Technology

2014-01-01

180

Radiation induced corrosion of copper for spent nuclear fuel storage  

NASA Astrophysics Data System (ADS)

The long term safety of repositories for radioactive waste is one of the main concerns for countries utilizing nuclear power. The integrity of engineered and natural barriers in such repositories must be carefully evaluated in order to minimize the release of radionuclides to the biosphere. One of the most developed concepts of long term storage of spent nuclear fuel is the Swedish KBS-3 method. According to this method, the spent fuel will be sealed inside copper canisters surrounded by bentonite clay and placed 500 m down in stable bedrock. Despite the importance of the process of radiation induced corrosion of copper, relatively few studies have been reported. In this work the effect of the total gamma dose on radiation induced corrosion of copper in anoxic pure water has been studied experimentally. Copper samples submerged in water were exposed to a series of total doses using three different dose rates. Unirradiated samples were used as reference samples throughout. The copper surfaces were examined qualitatively using IRAS and XPS and quantitatively using cathodic reduction. The concentration of copper in solution after irradiation was measured using ICP-AES. The influence of aqueous radiation chemistry on the corrosion process was evaluated based on numerical simulations. The experiments show that the dissolution as well as the oxide layer thickness increase upon radiation. Interestingly, the evaluation using numerical simulations indicates that aqueous radiation chemistry is not the only process driving the corrosion of copper in these systems.

Björkbacka, Åsa; Hosseinpour, Saman; Johnson, Magnus; Leygraf, Christofer; Jonsson, Mats

2013-11-01

181

Radiation-induced skin carcinomas of the head and neck  

SciTech Connect

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

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

1991-03-01

182

Intercellular Adhesion Molecule 1 Knockout Abrogates Radiation Induced Pulmonary Inflammation  

NASA Astrophysics Data System (ADS)

Increased expression of intercellular adhesion molecule 1 (ICAM-1; CD54) is induced by exposure to ionizing radiation. The lung was used as a model to study the role of ICAM-1 in the pathogenesis of the radiation-induced inflammation-like response. ICAM-1 expression increased in the pulmonary microvascular endothelium and not in the endothelium of larger pulmonary vessels following treatment of mice with thoracic irradiation. To quantify radiation-induced ICAM-1 expression, we utilized fluorescence-activated cell sorting analysis of anti-ICAM-1 antibody labeling of pulmonary microvascular endothelial cells from human cadaver donors (HMVEC-L cells). Fluorochrome conjugates and UV microscopy were used to quantify the fluorescence intensity of ICAM in the irradiated lung. These studies showed a dose- and time-dependent increase in ICAM-1 expression in the pulmonary microvascular endothelium. Peak expression occurred at 24 h, while threshold dose was as low as 2 Gy. To determine whether ICAM-1 is required for inflammatory cell infiltration into the irradiated lung, the anti-ICAM-1 blocking antibody was administered by tail vein injection to mice following thoracic irradiation. Inflammatory cells were quantified by immunofluorescence for leukocyte common antigen (CD45). Mice treated with the anti-ICAM-1 blocking antibody showed attenuation of inflammatory cell infiltration into the lung in response to ionizing radiation exposure. To verify the requirement of ICAM-1 in the inflammation-like radiation response, we utilized the ICAM-1 knockout mouse. ICAM-1 was not expressed in the lungs of ICAM-1-deficient mice following treatment with thoracic irradiation. ICAM-1 knockout mice had no increase in the inflammatory cell infiltration into the lung in response to thoracic irradiation. These studies demonstrate a radiation dose-dependent increase in ICAM-1 expression in the pulmonary microvascular endothelium, and show that ICAM-1 is required for inflammatory cell infiltration into the irradiated lung.

Hallahan, Dennis E.; Virudachalam, Subbulakshmi

1997-06-01

183

Radiation-induced cell death: importance of lysosomal destabilization  

PubMed Central

The mechanisms involved in radiation-induced cellular injury and death remain incompletely understood. In addition to the direct formation of highly reactive hydroxyl radicals (HO·) by radiolysis of water, oxidative stress events in the cytoplasm due to formation of H2O2 may also be important. Since the major pool of low-mass redox-active intracellular iron seems to reside within lysosomes, arising from the continuous intralysosomal autophagocytotic degradation of ferruginous materials, formation of H2O2 inside and outside these organelles may cause lysosomal labilization with release to the cytosol of lytic enzymes and low-mass iron. If of limited magnitude, such release may induce ‘reparative autophagocytosis’, causing additional accumulation of redox-active iron within the lysosomal compartment. We have used radio-resistant histiocytic lymphoma (J774) cells to assess the importance of intralysosomal iron and lysosomal rupture in radiation-induced cellular injury. We found that a 40 Gy radiation dose increased the ‘loose’ iron content of the (still viable) cells approx. 5-fold when assayed 24 h later. Cytochemical staining revealed that most redox-active iron was within the lysosomes. The increase of intralysosomal iron was associated with ‘reparative autophagocytosis’, and sensitized cells to lysosomal rupture and consequent apoptotic/necrotic death following a second, much lower dose of radiation (20 Gy) 24 h after the first one. A high-molecular-mass derivative of desferrioxamine, which specifically localizes intralysosomally following endocytic uptake, added to the culture medium before either the first or the second dose of radiation, stabilized lysosomes and largely prevented cell death. These observations may provide a biological rationale for fractionated radiation. PMID:15813701

2005-01-01

184

Kinetics and mechanisms of radiation-induced degradation of acetochlor.  

PubMed

The radiation-induced degradation of acetochlor was investigated in this work. In a mixed solvent composed of acetonitrile and water at a ratio of 20/80 in volume, the acetochlor degradation rate was proportional to the radiation dose rate and acetochlor concentration. The acetochlor degradation efficiency was higher under alkali conditions and lower under acidic conditions. The contribution to the acetochlor degradation by the radicals was in the order of: e(aq)->.OH>H.. The quantum efficiency ratios of .OH, e(aq)- and H. for the degradation of acetochlor were calculated as 1:3:1. PMID:15698639

Liu, Shao-Yang; Chen, You-Peng; Yu, Han-Qing; Zhang, Shu-Juan

2005-03-01

185

Dynamics of the UV-Induced Absorption of Laser Light by Color Centers in Crystalline KY3F10:Ce3+,Yb3+  

NASA Astrophysics Data System (ADS)

A pump-probe method is used to study the dynamics of the destruction of color centers in KY3F10:Ce3+ and KY3F10:Ce3+,Yb3+ crystals by continuous UV radiation and to measure its parameters. The effect of Yb3+ ions in crystalline KY3F10:Ce3+,Yb3+ on the rate of bleaching of color centers in it under exposure to the probe light is studied. Irradiation of KY3F10:Ce3+ and KY3F10:Ce3+,Yb3+ crystals at a wavelength corresponding to an absorption band of a color center accelerates the destruction of the color centers and the reduction of Yb2+ ions to the trivalent state in proportion to the density of the radiation. A model is constructed for the bleaching mechanism that can be used to estimate the ionization cross section of the color centers.

Morozov, O. A.; Naumov, A. K.; Tselisheva, E. Yu.; Lovchev, A. V.; Korableva, S. L.

2014-09-01

186

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

NASA Astrophysics Data System (ADS)

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

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

2004-04-01

187

Prevalence of minisatellite and microsatellite instability in radiation-induced post-Chernobyl pediatric thyroid carcinomas  

Microsoft Academic Search

Exposure to ionizing radiation induces different forms of genomic instability in cultured cells and experimental animals. A higher rate of germline mutations at human hypervariable minisatellite loci was reported in children born from parents exposed to radiation after Chernobyl, implicating genome destabilization as a possible mechanism responsible for late radiation effects in humans. To test if radiation-induced carcinogenesis in the

Yuri E Nikiforov; Marina Nikiforova; James A Fagin; A Fagin

1998-01-01

188

Oxidative Stress Mediates Radiation Lung Injury by Inducing Apoptosis  

PubMed Central

Purpose Apoptosis in irradiated normal lung tissue has been observed several weeks post radiation. However, the signaling pathway propagating cell death post-radiation remains unknown. Methods and Materials C57BL/6J mice were irradiated with 15 Gy to the whole thorax. Pro-apoptotic signaling was evaluated 6 weeks after radiation with or without administration of AEOL10150, a potent catalytic scavenger of reactive oxygen and nitrogen species. Results Apoptosis was observed primarily in type I and type II pneumocytes and endothelium. Apoptosis correlated with increased PTEN expression, inhibition of downstream PI3K/AKT signaling, and increased p53 and Bax protein levels. TGF-?1, Nox4, and oxidative stress were also increased 6 weeks after radiation. Therapeutic administration of AEOL10150 suppressed pro-apoptotic signaling and dramatically reduced the number of apoptotic cells. Conclusion Increased PTEN signaling after radiation results in apoptosis of lung parenchymal cells. We hypothesize that upregulation of PTEN is influenced by Nox4-derived oxidative stress. To our knowledge, this is the first study to highlight the role of PTEN in radiation-induced pulmonary toxicities. PMID:22270165

Zhang, Yu; Zhang, Xiuwu; Rabbani, Zahid N.; Jackson, Isabel L.; Vujaskovic, Zeljko

2013-01-01

189

Oxidative Stress Mediates Radiation Lung Injury by Inducing Apoptosis  

SciTech Connect

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

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

2012-06-01

190

Caffeine Markedly Enhanced Radiation-Induced Bystander Effects  

NASA Astrophysics Data System (ADS)

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

Jiang, Erkang; Wu, Lijun

2009-04-01

191

Pyridoxamine protects intestinal epithelium from ionizing radiation-induced apoptosis  

PubMed Central

Reactive oxygen species (ROS) and reactive carbonyl species (RCS) are the major cause of biological tissue damage during the exposure to ionizing radiation (IR). The existing strategies to protect normal tissues from detrimental effects of IR suffer from several shortcomings including high toxic side effects, unfavorable administration routs or low efficacy. These shortcomings emphasize a need for radioprotective treatments that combine effectiveness with safety and ease of use. In this paper, we demonstrate that pyridoxamine, a ROS and RCS scavenger with a very favorable safety profile, can inhibit IR-induced gastrointestinal endothelial apoptosis in cell culture and in animal model. Pyridoxamine was more effective at protecting from radiation-induced apoptosis compared to Amifostine, a synthetic thiol compound and the only FDA approved radioprotector. We suggest that PM has a potential as an effective and safe radioprotective agent. PMID:19540915

Thotala, Dinesh; Chetyrkin, Sergei; Hudson, Billy; Hallahan, Dennis; Voziyan, Paul; Yazlovitskaya, Eugenia

2009-01-01

192

Frequency and characteristics of docetaxel-induced radiation recall phenomenon  

SciTech Connect

Purpose: The aim of this study was to investigate the frequency and characteristics of a docetaxel-induced radiation recall phenomenon. Methods and Materials: Past histories of radiotherapy and radiation recall phenomenon (RRP) were analyzed in 461 patients who were administered docetaxel at our hospital between September 2002 and November 2005. Results: Of the 461 patients, 171 underwent radiotherapy before starting docetaxel. RRP was noted in 3 patients (1.8%). The 3 cases show that RRP tends to develop in patients treated with lower-energy photon beams of {<=}6 MV and in patients with marked acute phase reactions during radiotherapy. Conclusions: The incidence of RRP induced by docetaxel was 1.8%, making it a comparatively rare condition. However, docetaxel is increasingly being used for patients with head and neck tumors, and caution regarding development of RRP is warranted after use of docetaxel after high-dose radiotherapy with photon beams of {<=}6 MV.

Mizumoto, Masashi [Division of Radiation Oncology, Shizuoka Cancer Center Hospital, Nagaizumi, Shizuoka (Japan)]. E-mail: mizumoto1717@hotmail.com; Harada, Hideyuki [Division of Radiation Oncology, Shizuoka Cancer Center Hospital, Nagaizumi, Shizuoka (Japan); Asakura, Hirofumi [Division of Radiation Oncology, Shizuoka Cancer Center Hospital, Nagaizumi, Shizuoka (Japan); Zenda, Sadamoto [Division of Radiation Oncology, Shizuoka Cancer Center Hospital, Nagaizumi, Shizuoka (Japan); Fuji, Hiroshi [Division of Proton Therapy, Shizuoka Cancer Center Hospital, Nagaizumi, Shizuoka (Japan); Murayama, Shigeyuki [Division of Proton Therapy, Shizuoka Cancer Center Hospital, Nagaizumi, Shizuoka (Japan); Nishimura, Tetsuo [Division of Radiation Oncology, Shizuoka Cancer Center Hospital, Nagaizumi, Shizuoka (Japan)

2006-11-15

193

Opportunities for nutritional amelioration of radiation-induced cellular damage  

NASA Technical Reports Server (NTRS)

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

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

2002-01-01

194

Radiation-induced decomposition of PETN and TATB under pressure  

SciTech Connect

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.

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

2008-10-02

195

The effect of polymer composition on radiation-induced crosslinking  

Microsoft Academic Search

The gelation induced by Co⁶° gamma radiation in butadiene-styrene ; copolymers, homopolymers, and mixtures of these homopolymers was studied by use ; of random crosslinking theory. The number of crosslinks formed per 100 ev of ; energy absorbed by the polymer, G(X), was found to be 0.045 for polystyrene and ; 3.6 for polybutadiene. The behavior of styrene units in

Edward Witt

1959-01-01

196

Radioprotective effect of silymarin against radiation induced hepatotoxicity  

Microsoft Academic Search

The radioprotective effect of silymarin using different modes of treatment against radiation (3 or 6 Gy) induced hepatotoxicity 1, 3 and 7 days post-irradiation was studied. Whole-body gamma-irradiation revealed an increase in serum alkaline phosphatase (AP) activity as well as liver glutathione reductase (GR) and glutathione peroxidase (GSH-PX) activities on the first post-exposure day with respect to the control value.

Laila A. Ramadan; Hamed M. Roushdy; Gamal M. Abu Senna; Nour E. Amin; Ola A. El-Deshw

2002-01-01

197

Interlaboratory comparison of radiation-induced attenuation in optical fibers  

SciTech Connect

A comparison of the losses induced in step index multimode, graded index multimode and single mode fibers by pulsed radiation exposure has been made among 12 laboratories over a period of 5 years. The recoveries of the incremental attenuations from 10{sup -9} to 10{sup 1} s are reported. Although a standard set of measurement parameters was attempted, differences between the laboratories are evident; possible origins for these are discussed. 18 refs., 18 figs., 7 tabs.

Friebele, E.J.; Lyons, P.B.; Blackburn, J.C.; Henschel, H.; Johan, A.; Krinsky, J.A.; Robinson, A.; Schneider, W.; Smith, D.; Taylor, E.W. (Naval Research Lab., Washington, DC (USA); Los Alamos National Lab., NM (USA); Harry Diamond Labs., Adelphi, MD (USA); Fraunhofer-Institut fuer Naturwissenschaftlich-Technische Trendanalysen (INT), Euskirchen (Germany, F.R.); Direction des Recherches, Etudes et Techni

1989-08-01

198

Mechanisms of the formation of radiation-induced chromosomal aberrations.  

PubMed

Although much is now known about the mechanisms of radiation-induction of DNA double-strand breaks (DSB), there is less known about the conversion of DSB into chromosomal aberrations. In particular the induction and 'rejoining' of chromatid breaks has been a controversial topic for many years. However, its importance becomes clear in the light of the wide variation in the chromatid break response of human peripheral blood lymphocytes from different individuals when exposed to ionizing radiation, and the elevation of the frequency of radiation-induced chromatid breaks in stimulated peripheral blood lymphocytes of around 40% of breast cancer cases. A common assumption has been that chromatid breaks are merely expansions of initiating DSB, although the classic 'breakage-first' hypothesis (Sax, Ref. 44) was already challenged in the 50's by Revell [30] who maintained that chromatid breaks were formed as a result of an incomplete exchange process initiated by two interacting lesions of an unspecified nature. Here we argue that both these models of chromatid break formation are flawed and we suggest an alternative hypothesis, namely that a radiation-induced DSB initiates an indirect mechanism leading to a chromatid break. This mechanism we suggest involves the nuclear enzyme topoisomerase IIalpha and we present evidence from topoisomerase IIalpha expression variant human cell lines and from siRNA treatment of human cells that supports this hypothesis. PMID:20348019

Bryant, Peter E; Riches, Andrew C; Terry, Samantha Y A

2010-08-14

199

Environmental applications of radiation-induced defects in clay minerals  

NASA Astrophysics Data System (ADS)

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

Allard, T.

2011-12-01

200

Radiation-induced grain boundary segregation in austenitic stainless steels  

SciTech Connect

Radiation-induced segregation (RIS) to grain boundaries in Fe-Ni-Cr-Si stainless alloys has been measured as a function of irradiation temperature and dose. Heavy-ion irradiation was used to produce damage levels from 1 to 20 displacements per atom (dpa) at temperatures from 175 to 550{degrees}C. Measured Fe, Ni, and Cr segregation increased sharply with irradiation dose (from G to 5 dpa) and temperature (from 175 to about 350{degrees}C). However, grain boundary concentrations did not change significantly as dose or temperatures were further increased. Although interfacial compositions were similar, the width of radiation-induced enrichment or depletion profiles increased consistently with increasing dose or temperature. Impurity segregation (Si and P) was also measured, but only Si enrichment appeared to be radiation-induced. Grain boundary Si peaked at levels approaching 10 at% after irradiation doses to 10 dpa at an intermediate temperature of 325{degrees}C. No evidence of grain boundary silicide precipitation was detected after irradiation at any temperature. Equilibrium segregation of P was measured in the high-P alloys, but interfacial concentration did not increase with irradiation exposure. Comparisons to reported RIS in neutron-irradiated stainless steels revealed similar grain boundary compositional changes for both major alloying and impurity elements.

Bruemmer, S.M.; Charlot, L.A.; Vetrano, J.S.; Simonen, E.P.

1994-11-01

201

Targets for, and consequences of, radiation-induced chromosomal instability  

NASA Astrophysics Data System (ADS)

Chromosomal instability has been demonstrated in a human- hamster hybrid cell line, GM10115, after exposure to x- rays. Chromosomal instability in these cells is characterized by the appearance of novel chromosomal rearrangements multiple generations after exposure to ionizing radiation. To identify the cellular target(s) for radiation-induced chromosomal instability, cells were treated with 125I-labeled compounds. Labeling cells with 125I-iododeoxyuridine, which caused radiation damage to the DNA and associated nuclear structures, did induce chromosomal instability. While cell killing and first-division chromosomal rearrangements increased with increasing numbers of 125I decays, the frequency of chromosomal instability was independent of dose. Incorporation of an 125I-labeled protein, 125I-succinyl- concanavalin A, into either the plasma membrane or the cytoplasm, failed to elicit chromosomal instability. These results show that radiation damage to the nucleus, and not to extranuclear regions, contributes to the induction of chromosomal instability. To determine the role of DNA strand breaks as a molecular lesion responsible for initiating chromosomal instability, cells were treated with a variety of DNA strand breaking agents. Agents capable of producing complex DNA double strand breaks, including X-rays, Neocarzinostatin and bleomycin, were able to induce chromosomal instability. In contrast, double strand breaks produced by restriction endonucleases as well as DNA strand breaks produced by hydrogen peroxide failed to induce chromosomal instability. This demonstrates that the type of DNA breakage is important in the eventual manifestation of chromosomal instability. In order to understand the relationship between chromosomal instability and other end points of genomic instability, chromosomally stable and unstable clones were analyzed for sister chromatid exchange, delayed reproductive cell death, delayed mutation, mismatch repair and delayed gene amplification. Although individual clones within each group were significantly different from unirradiated clones for many of the endpoints, there was no significant correlation between chromosomal instability and the phenotypes of sister chromatid exchange, delayed mutation, and mismatch repair. Delayed gene amplification weakly correlated chromosomal instability (0.05 < p < 0.1) and delayed reproductive cell death correlated strongly (p < 0.05) with chromosomal instability. These data indicate that multiple pathways exist for inducing genomic instability in GM10115 cells after radiation exposure.

Kaplan, Mark Isaac

202

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

NASA Astrophysics Data System (ADS)

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

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

203

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

SciTech Connect

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

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

2013-08-01

204

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

PubMed Central

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

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

2010-01-01

205

Surface-Energy Induced Formation of Single Crystalline Bismuth Nanowires over Vanadium Thin Film at Room Temperature.  

PubMed

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

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

2014-10-01

206

Quantifying Local Radiation-Induced Lung Damage From Computed Tomography  

SciTech Connect

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

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

2010-02-01

207

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

NASA Technical Reports Server (NTRS)

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

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

2006-01-01

208

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

SciTech Connect

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.

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

1985-11-01

209

In Situ Mass Spectrometry Imaging and Ex Vivo Characterization of Renal Crystalline Deposits Induced in Multiple Preclinical Drug Toxicology Studies  

PubMed Central

Drug toxicity observed in animal studies during drug development accounts for the discontinuation of many drug candidates, with the kidney being a major site of tissue damage. Extensive investigations are often required to reveal the mechanisms underlying such toxicological events and in the case of crystalline deposits the chemical composition can be problematic to determine. In the present study, we have used mass spectrometry imaging combined with a set of advanced analytical techniques to characterize such crystalline deposits in situ. Two potential microsomal prostaglandin E synthase 1 inhibitors, with similar chemical structure, were administered to rats over a seven day period. This resulted in kidney damage with marked tubular degeneration/regeneration and crystal deposits within the tissue that was detected by histopathology. Results from direct tissue section analysis by matrix-assisted laser desorption ionization mass spectrometry imaging were combined with data obtained following manual crystal dissection analyzed by liquid chromatography mass spectrometry and nuclear magnetic resonance spectroscopy. The chemical composition of the crystal deposits was successfully identified as a common metabolite, bisulphonamide, of the two drug candidates. In addition, an un-targeted analysis revealed molecular changes in the kidney that were specifically associated with the area of the tissue defined as pathologically damaged. In the presented study, we show the usefulness of combining mass spectrometry imaging with an array of powerful analytical tools to solve complex toxicological problems occurring during drug development. PMID:23110069

Bjurstrom, Sivert; Goodwin, Richard J. A.; Basmaci, Elisa; Gustafsson, Ingela; Annas, Anita; Hellgren, Dennis; Svanhagen, Alexander; Andren, Per E.; Lindberg, Johan

2012-01-01

210

Radiation-induced esophageal injury: A spectrum from esophagitis to cancer  

SciTech Connect

Radiation esophagitis is a common but frequently unrecognized complication of therapeutic radiation to the neck, chest, or mediastinum. The spectrum of injury ranges from acute self-limited esophagitis to life-threatening esophageal perforation. Complications such as stricture or primary esophageal cancer may occur many years after irradiation, and their linkage to radiation may not be considered. Five cases of radiation-induced injury are described, and the spectrum of radiation-induced esophageal injury is reviewed.

Vanagunas, A.; Jacob, P.; Olinger, E. (Northwestern Univ. Medical School, Chicago, IL (USA))

1990-07-01

211

Should Cancer Survivors Fear Radiation-Induced Sarcomas?  

PubMed Central

Purpose/Results. Ionizing radiation is carcinogenic and the induction of a second malignancy is a serious potential long-term complication of radiotherapy. The incidence of radiation-induced sarcomas was evaluated from many large epidemiological surveys of long-term cancer survivors reported in the literature over the past 30 years and only one case was found for every 1000 patients irradiated. Discussion. Although greater numbers of cancer patients are receiving radical radiotherapy and surviving free of disease for longer intervals, cases of radiation-induced sarcomas are rare and should not deter patients from accepting radiotherapy as treatment for curable cancers. With improvements in the administration of radiotherapy over the past two decades which are resulting in less damage to bone and soft tissues, it is likely that fewer cases of this condition will be seen in the future. If these sarcomas are diagnosed early, long-term survival can be achieved with surgical excision and possibly re-irradiation, as occurs in other types of sarcomas. PMID:18521195

1997-01-01

212

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

SciTech Connect

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

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

2012-07-15

213

Space-radiation-induced photon luminescence of the Moon  

NASA Astrophysics Data System (ADS)

We report on the results of a continuing study of the photon luminescence of the Moon induced by Galactic Cosmic Rays (GCRs) and space radiation from the Sun, using the Monte Carlo program FLUKA. Understanding the space radiation environment is critical to future exploration of the Moon, and this includes photons. The model of the lunar surface is taken to be the chemical composition of soils found at various landing sites during the Apollo and Luna programs, averaged over all such sites to define a generic regolith for the present analysis. This surface model then becomes the target that is bombarded by Galactic Cosmic Rays (GCRs) and Solar Energetic Particles (SEPs) or Solar Particle Events (SPEs) above 1 keV in FLUKA to determine the photon fluence albedo produced by the Moon's surface when there is no sunlight and Earthshine. The result is to be distinguished from the gamma-ray spectrum produced by the radioactive decay of radiogenic constituents lying in the surface and interior of the Moon. From the photon fluence we derive the spectrum which can be utilized to examine existing lunar spectral data and to aid future orbiting instrumentation in the measurement of various components of the space-radiation-induced photon luminescence present on the Moon.

Lee, K. T.; Wilson, T. L.

2009-08-01

214

Sensitization of ionizing radiation-induced apoptosis by ursolic acid.  

PubMed

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

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

2012-03-01

215

Sensitivity to Radiation-Induced Cancer in Hemochromatosis  

SciTech Connect

The objectives of this pilot project using HFE-knockout homozygotes and heterozygotes are to (1) determine whether the knock-out mice have greater sensitivity to radiation-induced cancer of the colon, liver and breast, (2) establish the dependence of this sensitivity on the accumulation of iron, (3) determine the extent to which cell replication and apoptosis occur in these target tissues with varying iron load, and (4) correlate the increases in sensitivity with changes in insulin-related signaling in tumors and normal tissue from each target organ. Three experimental designs will be used in the pilot project. The sequence of experiments is designed to first explore the influence of iron load on the response and demonstrate that HFE knockout mice are more sensitive than the wild type to radiation-induced cancer in one or more of three target tissues (liver, colon and breast). The dose response relationships with a broader set of radiation doses will be explored in the second experiment. The final experiment is designed to explore the extent to which heterozygotes display the increased susceptibility to cancer induction and to independently assess the importance of iron load to the initiation versus promotion of tumors.

Bull. Richard J.; Anderson, Larry E.

2000-06-01

216

Radiation-induced adaptive response in fish cell lines.  

PubMed

There is considerable interest at present in low-dose radiation effects in non-human species. In this study gamma radiation-induced adaptive response, a low-dose radiation effect, was examined in three fish cell lines, (CHSE-214 (Chinook salmon), RTG-2 (rainbow trout) and ZEB-2J (zebrafish)). Cell survival after exposure to direct radiation with or without a 0.1 Gy priming dose, was determined using the colony forming assay for each cell line. Additionally, the occurrence of a bystander effect was examined by measuring the effect of irradiated cell culture medium from the fish cell lines on unexposed reporter cells. A non-linear dose response was observed for all cell lines. ZEB-2J cells were very sensitive to low doses and a hyper-radiosensitive (HRS) response was observed for doses <0.5 Gy. A typical protective adaptive response was not detected in any of the three fish cell lines tested. Rather, it was found that pre-exposure of these cells to 0.1 Gy radiation sensitized the cells to subsequent high doses. In CHSE-214 cells, increased sensitivity to subsequent high doses of radiation was observed when the priming and challenge doses were separated by 4 h; however, this sensitizing effect was no longer present when the interval between doses was greater than 8 h. Additionally, a "protective" bystander response was observed in these cell lines; exposure to irradiated medium from fish cells caused increased cloning efficiency in unirradiated reporter cells. The data confirm previous conclusions for mammalian cells that the adaptive response and bystander effect are inversely correlated and contrary to expectations probably have different underlying mechanisms. PMID:18054128

Ryan, Lorna A; Seymour, Colin B; O'Neill-Mehlenbacher, Alicia; Mothersill, Carmel E

2008-04-01

217

DNA damage induced by the direct effect of radiation  

NASA Astrophysics Data System (ADS)

We have studied the nature of DNA damage induced by the direct effect of radiation. The yields of single- (SSB) and double-strand breaks (DSB), base lesions and clustered damage were measured using the agarose gel electrophoresis method after exposing to various kinds of radiations to a simple model DNA molecule, fully hydrated closed-circular plasmid DNA (pUC18). The yield of SSB does not show significant dependence on linear energy transfer (LET) values. On the other hand, the yields of base lesions revealed by enzymatic probes, endonuclease III (Nth) and formamidopyrimidine DNA glycosylase (Fpg), which excise base lesions and leave a nick at the damage site, strongly depend on LET values. Soft X-ray photon (150 kVp) irradiation gives a maximum yield of the base lesions detected by the enzymatic probes as SSB and clustered damage, which is composed of one base lesion and proximate other base lesions or SSBs. The clustered damage is visualized as an enzymatically induced DSB. The yields of the enzymatically additional damages strikingly decrease with increasing levels of LET. These results suggest that in higher LET regions, the repair enzymes used as probes are compromised because of the dense damage clustering. The studies using simple plasmid DNA as a irradiation sample, however, have a technical difficulty to detect multiple SSBs in a plasmid DNA. To detect the additional SSBs induced in opposite strand of the first SSB, we have also developed a novel technique of DNA-denaturation assay. This allows us to detect multiply induced SSBs in both strand of DNA, but not induced DSB.

Yokoya, A.; Shikazono, N.; Fujii, K.; Urushibara, A.; Akamatsu, K.; Watanabe, R.

2008-10-01

218

Cerenkov emission induced by external beam radiation stimulates molecular fluorescence  

SciTech Connect

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

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

2011-07-15

219

Microbiota and radiation-induced bowel toxicity: lessons from inflammatory bowel disease for the radiation oncologist.  

PubMed

New gastrointestinal symptoms are frequent after pelvic radiotherapy and can greatly affect the quality of life of cancer survivors. The effect of radiation on the intestinal microbiota, and the clinical implications of a modified microbial balance after radiotherapy are now beginning to emerge. In this Personal View, we show the importance of the microbiota for intestinal homoeostasis, and discuss the similarity between inflammatory bowel disease, which has been extensively researched, and radiation-induced gastrointestinal toxicity. By use of microbiota profiles for risk assessment and manipulation of the intestinal flora for prevention and treatment of radiation, enteropathy could become a reality and would be of substantial relevance to the increasing numbers of long-term cancer survivors. PMID:24599929

Ferreira, Miguel R; Muls, Ann; Dearnaley, David P; Andreyev, H Jervoise N

2014-03-01

220

Involvement of inducible nitric oxide synthase in radiation-induced vascular endothelial damage.  

PubMed

The use of radiation therapy has been linked to an increased risk of cardiovascular disease. To understand the mechanisms underlying radiation-induced vascular dysfunction, we employed two models. First, we examined the effect of X-ray irradiation on vasodilation in rabbit carotid arteries. Carotid arterial rings were irradiated with 8 or 16 Gy using in vivo and ex vivo methods. We measured the effect of acetylcholine-induced relaxation after phenylephrine-induced contraction on the rings. In irradiated carotid arteries, vasodilation was significantly attenuated by both irradiation methods. The relaxation response was completely blocked by 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one, a potent inhibitor of soluble guanylate cyclase. Residual relaxation persisted after treatment with L-N(?)-nitroarginine (L-NA), a non-specific inhibitor of nitric oxide synthase (NOS), but disappeared following the addition of aminoguanidine (AG), a selective inhibitor of inducible NOS (iNOS). The relaxation response was also affected by tetraethylammonium, an inhibitor of endothelium-derived hyperpolarizing factor activity. In the second model, we investigated the biochemical events of nitrosative stress in human umbilical-vein endothelial cells (HUVECs). We measured iNOS and nitrotyrosine expression in HUVECs exposed to a dose of 4 Gy. The expression of iNOS and nitrotyrosine was greater in irradiated HUVECs than in untreated controls. Pretreatment with AG, L-N(6)-(1-iminoethyl) lysine hydrochloride (a selective inhibitor of iNOS), and L-NA attenuated nitrosative stress. While a selective target of radiation-induced vascular endothelial damage was not definitely determined, these results suggest that NO generated from iNOS could contribute to vasorelaxation. These studies highlight a potential role of iNOS inhibitors in ameliorating radiation-induced vascular endothelial damage. PMID:23704776

Hong, Chang-Won; Kim, Young-Mee; Pyo, Hongryull; Lee, Joon-Ho; Kim, Suwan; Lee, Sunyoung; Noh, Jae Myoung

2013-11-01

221

Treatment of radiation- and chemotherapy-induced stomatitis  

SciTech Connect

Severe stomatitis is a common problem encountered during either radiation therapy or chemotherapy. Most therapeutic regimens are empirical, with no scientific basis. The purpose of this study is to determine the efficacy of various topical solutions in the treatment of radiation- or chemotherapy-induced stomatitis. Eighteen patients were entered into a prospective double-blinded study to test several topical solutions: (1) viscous lidocaine with 1% cocaine; (2) dyclonine hydrochloride 1.0% (Dyclone); (3) kaolin-pectin solution, diphenhydramine plus saline (KBS); and (4) a placebo solution. Degree of pain relief, duration of relief, side effects, and palatability were evaluated. The results showed that Dyclone provided the most pain relief. Dyclone and viscous lidocaine with 1% cocaine provided the longest pain relief, which averaged 50 minutes This study provides objective data and defines useful guidelines for treatment of stomatitis.

Carnel, S.B.; Blakeslee, D.B.; Oswald, S.G.; Barnes, M. (Fitzsimons Army Medical Center, Aurora, CO (USA))

1990-04-01

222

Radiation-induced cerebral meningioma: a recognizable entity  

SciTech Connect

The authors retrospectively analyzed the clinical and histopathological findings in 201 patients with intracranial meningiomas operated on in the period 1978 to 1982. Forty-three of the patients (21.4%) had at some previous time received radiation treatment to their scalp, the majority for tinea capitis. The findings in these 43 irradiated patients were compared with those in the 158 non-irradiated patients. Several distinctive clinical and histological features were identified in the irradiated group, which suggest that radiation-induced meningiomas can be defined as a separate nosological subgroup. The use of irradiation in large numbers of children with tinea capitis in the era prior to the availability of griseofulvin may be responsible for a significantly increased incidence of intracranial meningiomas.

Rubinstein, A.B.; Shalit, M.N.; Cohen, M.L.; Zandbank, U.; Reichenthal, E.

1984-11-01

223

Radiation induced grafting of acrylic acid onto extruded polystyrene surface  

NASA Astrophysics Data System (ADS)

Polystyrene materials with good solubility in liquid scintillation cocktails are used to wipe off different types of surfaces in order to determine the tritium removable contamination with the help of a liquid scintillation counter. This paper analyses hydrophilic surface modifications by radiation induced grafting of acrylic groups onto extruded polystyrene plates. Two grafting methods were used: (a) exposure of extruded polystyrene plates, immersed in aqueous acrylic acid solution, to a gamma radiation of a Co-60 source, and (b) exposure of extruded polystyrene plates to a Co-60 source, followed by the immersion of extruded polystyrene plates in aqueous acrylic acid solution. The grafting of acrylic was proved by IR spectrometry and by radiometric methods using acrylic acid labelled with tritium.

Fugaru, Viorel; Bubueanu, George; Tuta, Catalin

2012-09-01

224

Solar radiation induced rotational bursting of interplanetary particles  

NASA Technical Reports Server (NTRS)

It is suggested that the magnitudes of the two radiation-induced rotational bursting mechanisms (Radzieskii effect and windmill effect) have been overestimated and that they do not work significantly faster than the Poynting-Robertson effect in removing interplanetary particles. These two mechanisms are described, and serious doubts are raised regarding the derivation of their radiation pressure-torque proportionality constants, which are required for calculating their magnitudes. It is shown that both mechanisms will cause the alignment of elongated particles and, consequently, the polarization of zodiacal light. Since no positive polarization has been measured at the antisolar point, it is concluded that the magnitudes of the rotational bursting mechanisms are smaller than that of the Poynting-Robertson effect.

Sparrow, J. G.

1975-01-01

225

Genomic instability induced by high and low LET ionizing radiation.  

PubMed

Genomic instability is the increased rate of acquisition of alterations in the mammalian genome, and includes such diverse biological endpoints as chromosomal destabilization, aneuploidy, micronucleus formation, sister chromatid exchange, gene mutation and amplification, variations in colony size, reduced plating efficiency, and cellular transformation. Because these multiple endpoints persist long after initial radiation exposure, genomic instability has been proposed to operate as a driving force contributing to genetic plasticity and carcinogenic potential. Many of these radiation-induced endpoints depend qualitatively and quantitatively on genetic background, dose and LET. Differences in the frequency and temporal expression of chromosomal instability depend on all three of the foregoing factors. On the other hand, many of these endpoints appear independent of dose and show bystander effects, implicating non-nuclear targets and epigenetic regulatory mechanisms. The present work will survey results concerning the LET dependence of genomic instability and the role of epigenetic mechanisms, with a particular emphasis on the endpoint of chromosomal instability. PMID:11542863

Limoli, C L; Ponnaiya, B; Corcoran, J J; Giedzinski, E; Kaplan, M I; Hartmann, A; Morgan, W F

2000-01-01

226

Radiation-induced transient absorption in optical fibers  

SciTech Connect

Transient absorption in optical fibers has been studied with emphasis on fast absorption components. Radiation damage was induced with a Febetron 706 electron accelerator, modified to deliver an electron pulse width of 1.1 ns. Dye lasers were synchronized to the accelerator to provide a light pulse through the fiber during the radiation pulse. The output light pulse was detected with a biplanar vacuum photodiode. Four scope traces were used on each electron pulse to monitor the Febetron output, the input drive pulse, and two records of the output pulse on two sweep speeds. Detailed data were acquired for times less than 100 ns after irradiation. An insulated enslosure was used to vary fiber temperature from -30/sup 0/C to + 250/sup 0/C. Several fibers were studied with emphasis on ITT T303 PCS fiber. Data were acquired at 600 and 850 nm. Theoretical modeling of the data is presented.

Looner, L.D.; Turquet de Beauregard, G.; Lyons, P.B.; Kelly, R.E.

1981-01-01

227

Method for increased sensitivity of radiation detection and measurement  

DOEpatents

Dose of radiation to which a body of crystalline material has been exposed is measured by exposing the body to optical radiation at a first wavelength, which is greater than about 540 nm, and measuring optical energy emitted from the body by luminescence at a second wavelength, which is longer than the first wavelength. Reduced background is accomplished by more thorough annealing and enhanced radiation induced luminescence is obtained by treating the crystalline material to coalesce primary damage centers into secondary damage centers.

Miller, Steven D. (Richland, WA)

1994-01-01

228

[Radiation-induced cancers: state of the art in 1997].  

PubMed

Scientists now have available a large amount of data dealing with radiation-induced neoplasms. These data went back to anecdotal observations which were made in the very first years of utilization of X-rays and radioactive elements. In fact, it is essentially the strict follow-up of the Japanese populations irradiated by the Hiroshima and Nagasaki bombing which allowed a more precise evaluation of the carcinogenicity of ionizing radiations. Further refinements came from therapeutical irradiations: it is now possible to study large cohorts of patients given well-known doses in well-defined volumes and followed for more than 20 years. Last but not least, a significant increase in the incidence and mortality of thyroid cancer has been detected in children contaminated by iodine radioisotopes after the Tchernobyl accident. Recently, some data suggested the emergence of "clusters" of leukemias close to some nuclear facilities, but this question remains highly polemical, both in France and in the UK. Other questions are still waiting for a precise answer; of course, the extrapolation of our available data to very low doses delivered at very low dose rates, but also the carcinogenic risk at high doses. For these "high" doses (about 30 to 70 Gy), a competition between mutagenesis and cell killing was expected, so that these dose levels were expected to be less carcinogenic than lower (a few sieverts) doses. Actually, recent data suggest that the carcinogenic risk goes on increasing up to relatively important doses. In addition, carcinogenic factors, such as tabacco, anticancer chemotherapy and individual susceptibility, are found more and more to be closely intricated with ionizing radiation in the genesis of a given cancer. Even if a number of questions are still pending, the already available data allow specialists, both in medicine and radioprotection, to edict strict rules which can be reasonably expected to have significantly reduced the risk of radiation-induced neoplasms in most situations. PMID:9614902

Cosset, J M

1997-01-01

229

Erythrocyte Stiffness during Morphological Remodeling Induced by Carbon Ion Radiation  

PubMed Central

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

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

2014-01-01

230

Strain-induced macroscopic magnetic anisotropy from smectic liquid-crystalline elastomer-maghemite nanoparticle hybrid nanocomposites.  

PubMed

We combine tensile strength analysis and X-ray scattering experiments to establish a detailed understanding of the microstructural coupling between liquid-crystalline elastomer (LCE) networks and embedded magnetic core-shell ellipsoidal nanoparticles (NPs). We study the structural and magnetic re-organization at different deformations and NP loadings, and the associated shape and magnetic memory features. In the quantitative analysis of a stretching process, the effect of the incorporated NPs on the smectic LCE is found to be prominent during the reorientation of the smectic domains and the softening of the nanocomposite. Under deformation, the soft response of the nanocomposite material allows the organization of the nanoparticles to yield a permanent macroscopically anisotropic magnetic material. Independent of the particle loading, the shape-memory properties and the smectic phase of the LCEs are preserved. Detailed studies on the magnetic properties demonstrate that the collective ensemble of individual particles is responsible for the macroscopic magnetic features of the nanocomposite. PMID:23677459

Haberl, Johannes M; Sánchez-Ferrer, Antoni; Mihut, Adriana M; Dietsch, Hervé; Hirt, Ann M; Mezzenga, Raffaele

2013-06-21

231

Molecular-dynamics simulations of stacking-fault-induced dislocation annihilation in prestrained ultrathin single-crystalline copper films  

SciTech Connect

We report results of large-scale molecular-dynamics simulations of dynamic deformation under biaxial tensile strain of prestrained single-crystalline nanometer-scale-thick face-centered cubic (fcc) copper films. Our results show that stacking faults, which are abundantly present in fcc metals, may play a significant role in the dissociation, cross slip, and eventual annihilation of dislocations in small-volume structures of fcc metals. The underlying mechanisms are mediated by interactions within and between extended dislocations that lead to annihilation of Shockley partial dislocations or formation of perfect dislocations. Our findings demonstrate dislocation starvation in small-volume structures with ultrathin film geometry, governed by a mechanism other than dislocation escape to free surfaces, and underline the significant role of geometry in determining the mechanical response of metallic small-volume structures.

Kolluri, Kedarnath; Gungor, M. Rauf; Maroudas, Dimitrios [Department of Chemical Engineering, University of Massachusetts, Amherst, Massachusetts 01003-3110 (United States)

2009-05-01

232

The Development of Countermeasures for Space Radiation Induced Adverse Health Effects  

Microsoft Academic Search

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

Ann Kennedy

2010-01-01

233

[Radiation-induced bystander effect: the important part of ionizing radiation response. Potential clinical implications].  

PubMed

It has long been a central radiobiological dogma that the damaging effects of ionizing radiation, such as cell death, cytogenetic changes, apoptosis, mutagenesis, and carcinogenesis, are the results of the direct ionization of cell structures, particularly DNA, or indirect damage via water radiolysis products. However, several years ago attention turned to a third mechanism of radiation, termed the "bystander effect" or "radiation-induced bystander effect" (RIBE). This is induced by agents and signals emitted by directly irradiated cells and manifests as a lowering of survival, cytogenetic damage, apoptosis enhancement, and biochemical changes in neighboring non-irradiated cells. The bystander effect is mainly observed in in vitro experiments using very low doses of alpha particles (range; mGy, cGy), but also after conventional irradiation (X-rays, gamma rays) at low as well as conventional doses. The mechanisms responsible for the bystander effect are complex and still poorly understood. It is believed that molecular signals released from irradiated cells induce different signaling ways in non-irradiated neighboring cells, leading to the observed events. The molecular signals may be transmitted through gap junction intercellular communication and through a medium transfer mechanism. The nature of these transmitted factors are diverse, and still not definitely established. It seems that RIBE may have important clinical implications for health risk associated with radiation exposure. Potentially, this effect may have important implications in the creation of whole-body or localized side effects in tissues beyond the irradiation field and also in low-dose radiological and radioisotope diagnostics. Factors emitted by irradiated cells may result in the risk of genetic instability, mutations, and second primary cancer induction. They might also have their own part in inducing and extending post-radiation side effects in normal tissue. The bystander effect may be a potentially harmful or a useful event in radiotherapy. The elevation of damage to tumor cells not directly hit by radiation or the initiation of tumor cell differentiation may increase the therapeutic ratio. If, however, molecular species secreted by irradiated tumor cells in vivo damage neighboring normal cells (epithelial and endothelial cells, fibroblasts, or lymphocytes), the bystander effect would be harmful and could lead to increased side effects in normal tissue. This is especially important in modern radiotherapy, as 3D conformal radiation therapy (3D-CRT) and intensity-modulated radiation therapy (IMRT) are aimed at diminishing the radiation dose in normal tissues. Recent in vivo studies on animals indicate that bystander effects may appear in organs and tissues remote from the irradiated field and the extension of tissue damage seems to be tissue-type dependent. However, recent experimental results indicate that non-irradiated cells that are neighbors of irradiated cells may diminish radiation damage in the radiation-focused cells. Less is known about the bystander effect during fractionated irradiation. Thus the clinical implications of the bystander effect and its possible modification for radiotherapeutic usefulness is still under debate. PMID:19724078

Wide?, Maria; Przybyszewski, Waldemar; Rzeszowska-Wolny, Joanna

2009-01-01

234

Radiation-induced morphoea treated with UVA-1 phototherapy.  

PubMed

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

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

2014-07-01

235

Transient radiation-induced absorption in laser materials  

SciTech Connect

Transient radiation-induced absorption losses in laser materials have been measured using a pulsed nuclear reactor. Reactor pulse widths of 70 to 90 {mu}s and absorbed doses of 1 to 7.5 krad have been used. Transmission recovery times and peak absorption coefficients are given. Materials tested include LiNbO{sub 3}, GSGG, silica substrates, and filter glasses used in the laser cavity. The filter glasses are tested at discrete wavelengths in the range 440--750 nm. Lithium niobate , MgO doped LiNbO{sub 3}, GSGG, and the silica substrates are tested at 1061 nm.

Brannon, P.J.

1994-12-31

236

Measurements of prompt radiation induced conductivity in Teflon (PTFE).  

SciTech Connect

We performed measurements of the prompt radiation induced conductivity (RIC) in thin samples of Teflon (PTFE) at the Little Mountain Medusa LINAC facility in Ogden, UT. Three mil (76.2 microns) samples were irradiated with a 0.5 %CE%BCs pulse of 20 MeV electrons, yielding dose rates of 1E9 to 1E11 rad/s. We applied variable potentials up to 2 kV across the samples and measured the prompt conduction current. Details of the experimental apparatus and analysis are reported in this report on prompt RIC in Teflon.

Hartman, E. Frederick; Zarick, Thomas Andrew; Sheridan, Timothy J.; Preston, E. [ITT Exelis Mission Systems, Colorado Springs, CO

2013-05-01

237

Induced scalarization in boson stars and scalar gravitational radiation  

NASA Astrophysics Data System (ADS)

The dynamical evolution of boson stars in scalar-tensor theories of gravity is considered in the physical (Jordan) frame. We focus on the study of spontaneous and induced scalarization, for which we take as initial data configurations on the well-known S branch of a single boson star in general relativity. We show that during the scalarization process a strong emission of scalar radiation occurs. The new stable configurations (S branch) of a single boson star within a particular scalar-tensor theory are also presented.

Ruiz, Milton; Degollado, Juan Carlos; Alcubierre, Miguel; Núñez, Darío; Salgado, Marcelo

2012-11-01

238

Investigation Into Radiation-Induced Compaction of Zerodur (trademark)  

NASA Technical Reports Server (NTRS)

Zerodur is a low coefficient of thermal expansion glass-ceramic material. This property makes Zerodur an excellent material for high precision optical substrates. Functioning as a high precision optical substrate, a material must be dimensionally stable in the system operating environment. Published data indicate that Zerodur is dimensionally unstable when exposed to large doses of ionizing radiation. The dimensional instability is discussed as an increase in Zerodur density. This increase in density is described as a compaction. Experimental data showing proton-induced compaction of Zerodur is presented. The dependence of compaction on proton dose was determined to be a power law relationship.

Edwards, D. L.; Herren, K.; Hayden, M.; McDonald, K.; Sims, J. A.; Semmel, C. L.

1996-01-01

239

X-radiation-induced differentiation of xenotransplanted human undifferentiated rhabdomyosarcoma  

SciTech Connect

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

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

1989-01-01

240

Galactic cosmic ray-induced radiation dose on terrestrial exoplanets.  

PubMed

This past decade has seen tremendous advancements in the study of extrasolar planets. Observations are now made with increasing sophistication from both ground- and space-based instruments, and exoplanets are characterized with increasing precision. There is a class of particularly interesting exoplanets that reside in the habitable zone, which is defined as the area around a star where the planet is capable of supporting liquid water on its surface. Planetary systems around M dwarfs are considered to be prime candidates to search for life beyond the Solar System. Such planets are likely to be tidally locked and have close-in habitable zones. Theoretical calculations also suggest that close-in exoplanets are more likely to have weaker planetary magnetic fields, especially in the case of super-Earths. Such exoplanets are subjected to a high flux of galactic cosmic rays (GCRs) due to their weak magnetic moments. GCRs are energetic particles of astrophysical origin that strike the planetary atmosphere and produce secondary particles, including muons, which are highly penetrating. Some of these particles reach the planetary surface and contribute to the radiation dose. Along with the magnetic field, another factor governing the radiation dose is the depth of the planetary atmosphere. The higher the depth of the planetary atmosphere, the lower the flux of secondary particles will be on the surface. If the secondary particles are energetic enough, and their flux is sufficiently high, the radiation from muons can also impact the subsurface regions, such as in the case of Mars. If the radiation dose is too high, the chances of sustaining a long-term biosphere on the planet are very low. We have examined the dependence of the GCR-induced radiation dose on the strength of the planetary magnetic field and its atmospheric depth, and found that the latter is the decisive factor for the protection of a planetary biosphere. PMID:24143867

Atri, Dimitra; Hariharan, B; Grießmeier, Jean-Mathias

2013-10-01

241

Zinc- or cadmium-pre-induced metallothionein protects human central nervous system cells and astrocytes from radiation-induced apoptosis.  

PubMed

We have shown the protection of human central nervous system (CNS) cultures by zinc (Zn) or cadmium (Cd)-pre-induced metallothionein (MT) synthesis from radiation-induced cytotoxicity (lactate dehydrogenase (LDH) release and neuronal dendritic injury). The present study is to further define the types of cell death induced by different dose levels of radiation and investigate the effect of MT induction (by Zn or Cd) on radiation-induced apoptosis in primary human CNS and astrocyte cultures. Apoptosis was detected by fragmented DNA electrophoresis, TUNEL technique, and propidium iodide staining. Expression of MT protein was examined by immunofluorescent staining. Results showed that exposure of primary human CNS cultures to 15 and 30 Gy gamma-radiation predominantly induced apoptotic cell death, while exposure to 60 Gy gamma-radiation predominantly induced necrotic cell death. Normal primary human CNS cultures showed weak MT staining, while primary human CNS cultures exposed to Zn or Cd showed intense MT staining. The induced apoptotic cell death by exposure to 30 Gy gamma-radiation increased to a maximum level at 12 and 24 h, and was reduced significantly by Zn or Cd pre-induced MT. Using primary human astrocytes, the induction of MT protein by Zn or Cd was further confirmed. The enhanced MT expression also afforded a significant protection from 30 Gy gamma-ray-induced apoptosis in the primary human astrocytes. These results suggest that MT protected human CNS cells from apoptosis following ionizing radiation, probably through its antioxidant property. PMID:14687759

Cai, Lu; Iskander, Sammy; Cherian, M George; Hammond, Robert R

2004-02-01

242

Follistatin Is Induced by Ionizing Radiation and Potentially Predictive of Radiosensitivity in Radiation-Induced Fibrosis Patient Derived Fibroblasts  

PubMed Central

Follistatin is a potent regulator of the inflammatory response and binds to and inhibits activin A action. Activin A is a member of the TGF? protein superfamily which has regulatory roles in the inflammatory response and in the fibrotic process. Fibrosis can occur following cell injury and cell death induced by agents such as ionizing radiation (IR). IR is used to treat cancer and marked fibrotic response is a normal tissue (non-tumour) consequence in a fraction of patients under the current dose regimes. The discovery and development of a therapeutic to abate fibrosis in these radiosensitive patients would be a major advance for cancer radiotherapy. Likewise, prediction of which patients are susceptible to fibrosis would enable individualization of treatment and provide an opportunity for pre-emptive fibrosis control and better tumour treatment outcomes. The levels of activin A and follistatin were measured in fibroblasts derived from patients who developed severe radiation-induced fibrosis following radiotherapy and compared to fibroblasts from patients who did not. Both follistatin and activin A gene expression levels were increased following IR and the follistatin gene expression level was lower in the fibroblasts from fibrosis patients compared to controls at both basal levels and after IR. The major follistatin transcript variants were found to have a similar response to IR and both were reduced in fibrosis patients. Levels of follistatin and activin A secreted in the fibroblast culture medium also increased in response to IR and the relative follistatin protein levels were significantly lower in the samples derived from fibrosis patients. The decrease in the follistatin levels can lead to an increased bioactivity of activin A and hence may provide a useful measurement to identify patients at risk of a severe fibrotic response to IR. Additionally, follistatin, by its ability to neutralise the actions of activin A may be of value as an anti-fibrotic for radiation induced fibrosis. PMID:24204752

McKay, Michael J.; Leong, Trevor; de Kretser, David M.; Sprung, Carl N.

2013-01-01

243

Space-Radiation-Induced Photon Luminescence of the Moon  

NASA Astrophysics Data System (ADS)

We report on the results of a study of the photon luminescence of the Moon induced by Galactic Cosmic Rays (GCRs) and space radiation from the Sun, using the Monte Carlo program FLUKA. The model of the lunar surface is taken to be the chemical composition of soils found at various landing sites during the Apollo and Luna programs, averaged over all such sites to define a generic regolith for the present analysis. This then becomes the target that is bombarded by Galactic Cosmic Rays (GCRs) and Solar Energetic Particles (SEPs) above 1 keV in FLUKA to determine the photon fluence albedo produced by the Moon's surface when there is no sunlight and Earthshine. This is to be distinguished from the gamma-ray spectrum produced by the radioactive decay of radiogenic constituents lying in the surface and interior of the Moon. From the photon fluence we derive the spectrum which can be utilized to examine existing lunar spectral data and to design orbiting instrumentation for measuring various components of the space-radiation-induced photon luminescence present on the Moon.

Wilson, Thomas

244

Swelling and radiation-induced segregation in austentic alloys  

NASA Astrophysics Data System (ADS)

To elucidate the relationship between radiation-induced segregation and swelling in austenitic stainless steels, a series of alloys were irradiated with 3.2 MeV protons to doses of 0.5 and 1.0 dpa at 400 °C. Three alloy series were irradiated, the first to examine the effect of bulk nickel in Fe-16-18Cr- xNi, the second to determine the effect of Mo and P in an Fe-16Cr-13Ni base alloy, and the third to examine the effect of oversized solute Zr addition to an Fe-18Cr-0.5Ni alloy. The addition of nickel in Fe-16-18Cr- xNi caused a significant decrease in swelling and increase in segregation. The addition of Mo+P to Fe-16Cr-13Ni eliminated swelling and reduced segregation. The addition of Zr to Fe-18Cr-9.5Ni decreased swelling and altered the segregation. Comparison of swelling with changes in lattice parameter and shear modulus caused by the segregation showed that swelling correlates well with the decreases in lattice parameter caused by radiation-induced segregation. Those alloys whose segregation decreased the lattice parameter the greatest showed the lowest swelling. These results are consistent with theoretical predictions made by Wolfer.

Allen, T. R.; Cole, J. I.; Gan, J.; Was, G. S.; Dropek, R.; Kenik, E. A.

2005-06-01

245

Gossypol enhances radiation induced autophagy in glioblastoma multiforme.  

PubMed

Malignant gliomas (glioblastoma multiforme) are the most aggressive of the primary brain tumors. Radiotherapy is an important tool for treatment of cancer but malignant gliomas are usually resistant to radiotherapy and other adjuvant therapies. Thus new drugs are needed to increase the efficiency of radiotherapy in order to improve the therapeutic outcome of tumor patients. Recent investigations showed that gossypol, natural polyphenolic compound produced by cotton plants, is a promising agent against solid tumors. The current study was defined to evaluate whether the combinatorial effect of radiation and gossypol would induce higher level of cell death on U-87 MG than single agent treatment and its possible mechanism of action. Clonogenic survival assay showed that ionizing radiation plus gossypol significantly inhibited clonogenic growth of irradiated cells as compared with either treatment alone. Acridine orange/etidium bromide staining confirmed that there was no significant increase in necrotic and apoptotic cells, but irradiated cells in combination with gossypol showed a significant increase in accumulation of acidic vesicular organelle. The results obtained herein indicated that gossypol is a promising drug that induced autophagic cell death in radioresistant malignant glioma. PMID:24968413

Keshmiri-Neghab, Hoda; Goliaei, Bahram; Nikoofar, Alireza

2014-10-01

246

Radiation-induced genomic instability in Caenorhabditis elegans.  

PubMed

Radiation-induced genomic instability has been well documented, particularly in vitro. However, the understanding of its mechanisms and their consequences in vivo is still limited. In this study, Caenorhabditis elegans (C. elegans; strain CB665) nematodes were exposed to X-rays at doses of 0.1, 1, 3 or 10Gy. The endpoints were measured several generations after exposure and included mutations in the movement-related gene unc-58, alterations in gene expression analysed with oligoarrays containing the entire C. elegans genome, and micro-satellite mutations measured by capillary electrophoresis. The progeny of the irradiated nematodes showed an increased mutation frequency in the unc-58 gene, with a maximum response observed at 1Gy. Significant differences were also found in gene expression between the irradiated (1Gy) and non-irradiated nematode lines. Differences in gene expression did not show clear clustering into certain gene categories, suggesting that the instability might be a chaotic process rather than a result of changes in the function of few specific genes such as, e.g., those responsible for DNA repair. Increased heterogeneity in gene expression, which has previously been described in irradiated cultured human lymphocytes, was also observed in the present study in C. elegans, the coefficient of variation of gene expression being higher in the progeny of irradiated nematodes than in control nematodes. To the best of our knowledge, this is the first publication reporting radiation-induced genomic instability in C. elegans. PMID:22796420

Huumonen, Katriina; Immonen, Hanna-Kaisa; Baverstock, Keith; Hiltunen, Mikko; Korkalainen, Merja; Lahtinen, Tapani; Parviainen, Juha; Viluksela, Matti; Wong, Garry; Naarala, Jonne; Juutilainen, Jukka

2012-10-01

247

Radiation-induced versus endogenous DNA damage: possible effect of inducible protective responses in mitigating endogenous damage  

Microsoft Academic Search

Ionizing radiation (IR) causes damage to DNA that is apparently proportional to absorbed dose. The incidence of radiation-induced cancer in humans unequivocally rises with the value of absorbed doses above about 300 mGy, in a seemingly linear fashion. Extrapolation of this linear correlation down to zero-dose constitutes the linear-no-threshold (LNT) hypothesis of radiation-induced cancer incidence. The corresponding dose-risk correlation, however,

Myron Pollycove; Ludwig E Feinendegen

2003-01-01

248

Robust Feedback Control of Flow Induced Structural Radiation of Sound  

NASA Technical Reports Server (NTRS)

A significant component of the interior noise of aircraft and automobiles is a result of turbulent boundary layer excitation of the vehicular structure. In this work, active robust feedback control of the noise due to this non-predictable excitation is investigated. Both an analytical model and experimental investigations are used to determine the characteristics of the flow induced structural sound radiation problem. The problem is shown to be broadband in nature with large system uncertainties associated with the various operating conditions. Furthermore the delay associated with sound propagation is shown to restrict the use of microphone feedback. The state of the art control methodologies, IL synthesis and adaptive feedback control, are evaluated and shown to have limited success for solving this problem. A robust frequency domain controller design methodology is developed for the problem of sound radiated from turbulent flow driven plates. The control design methodology uses frequency domain sequential loop shaping techniques. System uncertainty, sound pressure level reduction performance, and actuator constraints are included in the design process. Using this design method, phase lag was added using non-minimum phase zeros such that the beneficial plant dynamics could be used. This general control approach has application to lightly damped vibration and sound radiation problems where there are high bandwidth control objectives requiring a low controller DC gain and controller order.

Heatwole, Craig M.; Bernhard, Robert J.; Franchek, Matthew A.

1997-01-01

249

Radiation induced thyroid neoplasms 1920 to 1987: A vanishing problem  

SciTech Connect

Radiation for benign diseases has been implicated as an etiologic factor in thyroid cancer. From 1930-60, over 2 million children may have been exposed to therapeutic radiation and it is estimated that up to 7% may develop thyroid cancer after a 5-40 year latency. Thyroid stimulating hormone, secondary to radioinduced hypothyroidism, has been implicated as causative in animals. Such data has led to expensive screening programs in high risk patients. Because of a decline in irradiation for benign diseases in children over the last 2 decades, we questioned whether the incidence of radiation induced thyroid neoplasms (RITN) was also decreasing. Twenty-six of 227 patients (11%) with thyroid malignancies seen at our institution from 1974-87 had a history of previous head and neck irradiation. These included 13 papillary, 3 follicular, and 7 mixed carcinomas as well as 2 lymphomas and 1 synovial cell sarcoma. None of these 26 patients had abnormal thyroid function tests at presentation. Mean latency from irradiation to the diagnosis of thyroid cancer was 25.4 years (6-55 year range). Compared to the reported increasing incidence of RITN from 1940-70, there appears to be a significant decrease since 1970. Based on our analysis, the use of expensive screening programs in high risk populations may no longer be warranted. Additionally, the routine use of thyroid replacement in previously irradiated chemically hypothyroid patients is not recommended.30 references.

Mehta, M.P.; Goetowski, P.G.; Kinsella, T.J.

1989-06-01

250

UVB radiation induced effects on cells studied by FTIR spectroscopy  

E-print Network

We have made a preliminary analysis of the results about the eVects on tumoral cell line (lymphoid T cell line Jurkat) induced by UVB radiation (dose of 310 mJ/cm^2) with and without a vegetable mixture. In the present study, we have used two techniques: Fourier transform infrared spectroscopy (FTIR) and flow cytometry. FTIR spectroscopy has the potential to provide the identiWcation of the vibrational modes of some of the major compounds (lipid, proteins and nucleic acids) without being invasive in the biomaterials. The second technique has allowed us to perform measurements of cytotoxicity and to assess the percentage of apoptosis. We already studied the induction of apoptotic process in the same cell line by UVB radiation; in particular, we looked for correspondences and correlations between FTIR spetroscopy and flow cytometry data finding three highly probable spectroscopic markers of apoptosis (Pozzi et al. in Radiat Res 168:698-705, 2007). In the present work, the results have shown significant changes ...

Di Giambattista, Lucia; Gaudenzi, S; Pozzi, D; Grandi, M; Morrone, S; Silvestri, I; Castellano, A Congiu; 10.1007/s00249-009-0446-9

2010-01-01

251

Bubble translation and deformation induced by ultrasound radiation force  

NASA Astrophysics Data System (ADS)

Measurement of small-bubble dynamics has been proposed for the remote evaluation of tissue elasticity [Erpelding et al., Proc. IEEE Ultrasonics Symp., 554-557, 2003]. For example, a microbubble can be produced within the cornea during femtosecond laser surgery and its response to a pulsed ultrasonic radiation force can be measured. The bubble's translation, deformation, and oscillation can be directly related to the mechanical properties of surrounding tissue information that is required for optimization of the surgical procedure. In the work reported here, a model was developed to predict the translation and deformation of an initially spherical bubble in a soft viscoelastic medium as induced by radiation pressure. The extent of bubble translation and deformation is dictated by the elastic stress and viscous forces that oppose the radiation pressure. Numerical simulations predict static, periodic, and transient translation of the bubble in response to continuous, periodic, and pulsed waveforms, respectively. The model also predicts the deformation of the bubble. The results indicate increased deformations with increased bubble translations. Overall, the model can be used to determine the local shear modulus and viscosity of the medium based on measurements of gas-bubble displacement. [Work supported by ARL:UT IR&D.

Ilinskii, Yurii A.; Meegan, G. Douglas; Zabolotskaya, Evgenia A.; Emelianov, Stanislav Y.

2001-05-01

252

Molecular Mechanisms and Treatment of Radiation-Induced Lung Fibrosis  

PubMed Central

Radiation-induced lung fibrosis (RILF) is a severe side effect of radiotherapy in lung cancer patients that presents as a progressive pulmonary injury combined with chronic inflammation and exaggerated organ repair. RILF is a major barrier to improving the cure rate and well-being of lung cancer patients because it limits the radiation dose that is required to effectively kill tumor cells and diminishes normal lung function. Although the exact mechanism is unclear, accumulating evidence suggests that various cells, cytokines and regulatory molecules are involved in the tissue reorganization and immune response modulation that occur in RILF. In this review, we will summarize the general symptoms, diagnostics, and current understanding of the cells and molecular factors that are linked to the signaling networks implicated in RILF. Potential approaches for the treatment of RILF will also be discussed. Elucidating the key molecular mediators that initiate and control the extent of RILF in response to therapeutic radiation may reveal additional targets for RILF treatment to significantly improve the efficacy of radiotherapy for lung cancer patients.

Ding, Nian-Hua; Li, Jian Jian; Sun, Lun-Quan

2013-01-01

253

Interaction of alpha radiation with thermally-induced defects in silicon  

SciTech Connect

The interaction of radiation-induced defects created by energetic alpha particles and thermally-induced defects in silicon has been studied using a Deep Level Transient Spectroscopy (DLTS) technique. Two thermally-induced defects at energy positions E{sub c}-0.48 eV and E{sub c}-0.25 eV and three radiation-induced defects E2, E3 and E5 have been observed. The concentration of both of the thermally-induced defects has been observed to increase on irradiation. It has been noted that production rates of the radiation-induced defects are suppressed in the presence of thermally-induced defects. A significant difference in annealing characteristics of thermally-induced defects in the presence of radiation-induced defects has been observed compared to the characteristics measured in pre-irradiated samples.

Ali, Akbar [Advance Materials Physics Lab. Department of Physics, Quaid-i-Azam University, Islamabad (Pakistan)], E-mail: aarandhawa@yahoo.com; Majid, Abdul [Advance Materials Physics Lab. Department of Physics, Quaid-i-Azam University, Islamabad (Pakistan)], E-mail: abdulmajid40@yahoo.com

2008-01-15

254

Image-based modeling of radiation-induced foci  

NASA Astrophysics Data System (ADS)

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

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

255

An amino acid mixture mitigates radiation-induced gastrointestinal toxicity.  

PubMed

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

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

2014-06-01

256

Molecular Genetic Alterations in Radiation-Induced Astrocytomas  

PubMed Central

Astrocytic tumors occasionally arise in the central nervous system following radiotherapy. It is not clear if these gliomas represent a unique molecular genetic subset. We identified nine cases in which an astrocytoma arose within ports of previous radiation therapy, with total doses ranging from 2400 to 5500 cGy. Irradiated primary lesions included craniopharyngioma, pituitary adenoma, Hodgkin’s lymphoma, ependymoma, pineal neoplasm, rhabdomyosarcoma, and three cases of lymphoblastic malignancies. Patients ranged from 9 to 60 years of age and developed secondary tumors 5 to 23 years after radiotherapy. The 9 postradiation neoplasms presented as either anaplastic astrocytoma (3 cases) or glioblastoma multiforme (6 cases). Two of the latter contained malignant mesenchymal components. We performed DNA sequence analysis, differential polymerase chain reaction (PCR), and quantitative PCR on DNA from formalin-fixed, paraffin-embedded tumors to evaluate possible alterations of p53, PTEN, K-ras, EGFR, MTAP, and p16 (MTS1/CDKN2) genes. By quantitative PCR, we found EGFR gene amplification in 2 of 8 tumors. One of these demonstrated strong immunoreactivity for EGFR. Quantitative PCR showed chromosome 9p deletions including p16 tumor suppressor gene (2 of 7 tumors) and MTAP gene (3 of 7). Five of 9 tumors demonstrated diffuse nuclear immunoreactivity for p53 protein. Sequencing of the p53 gene in these 9 cases revealed a mutation in only one of these cases, a G-to-A substitution in codon 285 (exon 8). Somewhat unexpectedly, no mutations were identified in PTEN, a commonly altered tumor suppressor gene in de novo glioblastoma multiformes. Unlike some radiation-induced tumors, no activating point mutations of the K-ras proto-oncogene or base pair deletions of tumor suppressor genes were noted. These radiation-induced tumors are distinctive in their high histological grade at clinical presentation. The spectrum of molecular genetic alterations appears to be similar to that described in spontaneous high grade astrocytomas, especially those of the de novo type. PMID:10329596

Brat, Daniel J.; James, C. David; Jedlicka, Anne E.; Connolly, Denise C.; Chang, Ed; Castellani, Rudy J.; Schmid, Mathias; Schiller, Martin; Carson, Dennis A.; Burger, Peter C.

1999-01-01

257

Radiation-induced alterations in histone modification patterns and their potential impact on short-term radiation effects  

PubMed Central

Detection and repair of radiation-induced DNA damage occur in the context of chromatin. An intricate network of mechanisms defines chromatin structure, including DNA methylation, incorporation of histone variants, histone modifications, and chromatin remodeling. In the last years it became clear that the cellular response to radiation-induced DNA damage involves all of these mechanisms. Here we focus on the current knowledge on radiation-induced alterations in post-translational histone modification patterns and their effect on the chromatin accessibility, transcriptional regulation and chromosomal stability. PMID:23050241

Friedl, Anna A.; Mazurek, Belinda; Seiler, Doris M.

2012-01-01

258

FEM numerical analysis of excimer laser induced modification in alternating multi-layers of amorphous and nano-crystalline silicon films  

NASA Astrophysics Data System (ADS)

UV excimer laser annealing (UV-ELA) is an alternative annealing process that, during the last few years, has gained enormous importance for the CMOS nano-electronic technologies, with the ability to provide films and alloys with electrical and optical properties to fit the desired device performance. The UV-ELA of amorphous (a-) and/or doped nano-crystalline (nc-) silicon films is based on the rapid (nanoseconds) formation of temperature profiles caused by laser radiation that is absorbed in the material and lead to crystallisation, diffusion in solid or even in liquid phase. To achieve the desired temperature profiles and to optimize the parameters involved in the processing of hydrogenated nanocrystalline silicon (nc-Si:H) films with the UV-ELA, a numerical analysis by finite element method (FEM) of a multilayer structure has been performed. The multilayer structures, consisting of thin alternating a-Si:H(10 nm) and n-doped nc-Si:H(60 nm) layers, deposited on a glass substrate, has also been experimentally analyzed. Temperature profiles caused by 193 nm radiation with 25 ns pulse length and energy densities ranging from 50 mJ/cm2 to 400 mJ/cm2 have been calculated. Numerical results allowed us to estimate the dehydrogenation process of the different layers and the diffusion of phosphorous (P) in Si layers as well as their structural modifications as a function of the applied laser energy density. Numerical results are compared with exhaustive characterization of the experimental results.

Conde, J. C.; Martín, E.; Stefanov, S.; Alpuim, P.; Chiussi, S.

2012-09-01

259

Compound K suppresses ultraviolet radiation-induced apoptosis by inducing DNA repair in human keratinocytes.  

PubMed

Ultraviolet (UV)-induced DNA damage is a crucial molecular trigger for sunburn cell formation and skin cancer. Nucleotide excision repair (NER) is the main mechanism in repairing UVB-induced DNA damage of mammalian cells. The purpose of this study is to investigate the functional role of ginsenoside compound K on HaCaT cells (a keratinocyte-derived permanent cell line) irradiated by UV. Hoechst 33258 staining were performed in analyzing UV-induced apoptosis on keratinocytes which were treated with compound K. ImmunoDotBlot assay was used in detecting cyclobutane pyrimidine dimers, the main DNA damage. Western blot analysis was applied for analyzing XPC and ERCC1, two of the NER proteins. Compound K inhibited UV-induced apoptosis of keratinocytes and caused a notable reduction in UV-specific DNA lesions which was due to induction of DNA repair. In agreement with this, compound K induced the expression of particular components of the NER complex, such as XPC and ERCC1. Our results demonstrate that compound K can protect cells from apoptosis induced by UV radiation by inducing DNA repair. PMID:19023546

Cai, Bao-Xiang; Luo, Dan; Lin, Xiang-Fei; Gao, Jie

2008-11-01

260

Radiation-induced chromatid breaks as a predictor of breast cancer risk  

Microsoft Academic Search

Purpose: In in vivo models, radiation-induced genomic instability correlates with the risk of breast cancer development. In addition, homozygous mutations in tumor suppressor genes associated with breast cancer development adversely affects the processing and repair of radiation-induced DNA damage. We performed a case-control study to determine whether an assay measuring radiation-induced chromatid breaks correlated with the risk of having bilateral

Thomas A Buchholz; Xifeng Wu

2001-01-01

261

Ionizing radiation induces tumor cell lysyl oxidase secretion  

PubMed Central

Background Ionizing radiation (IR) is a mainstay of cancer therapy, but irradiation can at times also lead to stress responses, which counteract IR-induced cytotoxicity. IR also triggers cellular secretion of vascular endothelial growth factor, transforming growth factor ? and matrix metalloproteinases, among others, to promote tumor progression. Lysyl oxidase is known to play an important role in hypoxia-dependent cancer cell dissemination and metastasis. Here, we investigated the effects of IR on the expression and secretion of lysyl oxidase (LOX) from tumor cells. Methods LOX-secretion along with enzymatic activity was investigated in multiple tumor cell lines in response to irradiation. Transwell migration assays were performed to evaluate invasive capacity of naïve tumor cells in response to IR-induced LOX. In vivo studies for confirming IR-enhanced LOX were performed employing immunohistochemistry of tumor tissues and ex vivo analysis of murine blood serum derived from locally irradiated A549-derived tumor xenografts. Results LOX was secreted in a dose dependent way from several tumor cell lines in response to irradiation. IR did not increase LOX-transcription but induced LOX-secretion. LOX-secretion could not be prevented by the microtubule stabilizing agent patupilone. In contrast, hypoxia induced LOX-transcription, and interestingly, hypoxia-dependent LOX-secretion could be counteracted by patupilone. Conditioned media from irradiated tumor cells promoted invasiveness of naïve tumor cells, while conditioned media from irradiated, LOX- siRNA-silenced cells did not stimulate their invasive capacity. Locally applied irradiation to tumor xenografts also increased LOX-secretion in vivo and resulted in enhanced LOX-levels in the murine blood serum. Conclusions These results indicate a differential regulation of LOX-expression and secretion in response to IR and hypoxia, and suggest that LOX may contribute towards an IR-induced migratory phenotype in sublethally-irradiated tumor cells and tumor progression. PMID:25052686

2014-01-01

262

Chemoprevention of ultraviolet radiation-induced skin cancer.  

PubMed Central

The use of chemical and physical sunscreening agents has increased dramatically during the last two to three decades as an effective means of preventing sunbum. The use of high sunprotection factor sunscreens has also been widely promoted for the prevention of skin cancer, including melanoma. Whereas sunscreens are undoubtedly effective in preventing sunbum, their efficacy in preventing skin cancer, especially melanoma, is currently under considerable debate. Sunscreens have been shown to prevent the induction of DNA damage that presumably results from the direct effects of ultraviolet radiation (UVR) on DNA. DNA damage has been identified as an initiator of skin cancer formation. However, both laboratory and epidemiological studies indicate that sunscreens may not block the initiation or promotion of melanoma formation. These studies suggest that the action spectrum for erythema induction is different than the action spectrum for the induction of melanoma. Indeed, recent reports on the wavelength dependency for the induction of melanoma in a fish model indicate that the efficacy of ultraviolet A wavelengths (320-400 nm) to induce melanoma is orders of magnitude higher than would be predicted from the induction of erythema in man or nonmelanoma skin tumors in mice. Other strategies for the chemoprevention of skin cancer have also been reported. Low levels and degree of unsaturation of dietary fats protect against UVR-induced skin cancer in mice humens. Compounds with antioxidant activity, including green tea extracts (polyphenols), have been reported to inhibit UVR-induced skin carcinogenesis. PMID:9255591

Ley, R D; Reeve, V E

1997-01-01

263

Coupled effects of director orientations and boundary conditions on light induced bending of monodomain nematic liquid crystalline polymer plates  

NASA Astrophysics Data System (ADS)

A photo-chromic liquid crystal polymers (LCPs) is a smart material for large light-activated variation or bending to transfer luminous energy into mechanical energy. We study the light induced behavior by modeling planar and homeotropic nematic network polymer plates. We effectively illustrate some reported experimental outcomes and theoretically predict some possible bending patterns. This paper constructs an understanding between the bending behaviors and interactions among the alignments, aspect ratios and boundary conditions, etc. Our work provides information on optimizing light induced bending in the process of micro-opto-mechanical system (MOMS) design.

You, Yue; Xu, Changwei; Ding, Shurong; Huo, Yongzhong

2012-12-01

264

Motion-induced radiation from electrons moving in Maxwell's fish-eye  

PubMed Central

In ?erenkov radiation and transition radiation, evanescent wave from motion of charged particles transfers into radiation coherently. However, such dissipative motion-induced radiations require particles to move faster than light in medium or to encounter velocity transition to pump energy. Inspired by a method to detect cloak by observing radiation of a fast-moving electron bunch going through it by Zhang et al., we study the generation of electron-induced radiation from electrons' interaction with Maxwell's fish-eye sphere. Our calculation shows that the radiation is due to a combination of ?erenkov radiation and transition radiation, which may pave the way to investigate new schemes of transferring evanescent wave to radiation. PMID:24166002

Liu, Yangjie; Ang, L. K.

2013-01-01

265

Motion-induced radiation from electrons moving in Maxwell's fish-eye.  

PubMed

In ?erenkov radiation and transition radiation, evanescent wave from motion of charged particles transfers into radiation coherently. However, such dissipative motion-induced radiations require particles to move faster than light in medium or to encounter velocity transition to pump energy. Inspired by a method to detect cloak by observing radiation of a fast-moving electron bunch going through it by Zhang et al., we study the generation of electron-induced radiation from electrons' interaction with Maxwell's fish-eye sphere. Our calculation shows that the radiation is due to a combination of ?erenkov radiation and transition radiation, which may pave the way to investigate new schemes of transferring evanescent wave to radiation. PMID:24166002

Liu, Yangjie; Ang, L K

2013-01-01

266

Characteristics of an oxidation-induced inversion layer in compensated p-type crystalline This article has been downloaded from IOPscience. Please scroll down to see the full text article.  

E-print Network

Characteristics of an oxidation-induced inversion layer in compensated p-type crystalline silicon. Sci. Technol. 25 (2010) 055009 (5pp) doi:10.1088/0268-1242/25/5/055009 Characteristics of an oxidation in this article are in colour only in the electronic version) 1. Introduction The photovoltaic industry is rapidly

267

Radiation-induced segregation and phase stability in ferritic-martensitic alloy T 91  

NASA Astrophysics Data System (ADS)

Radiation-induced segregation in ferritic-martensitic alloy T 91 was studied to understand the behavior of solutes as a function of dose and temperature. Irradiations were conducted using 2 MeV protons to doses of 1, 3, 7 and 10 dpa at 400 °C. Radiation-induced segregation at prior austenite grain boundaries was measured, and various features of the irradiated microstructure were characterized, including grain boundary carbide coverage, the dislocation microstructure, radiation-induced precipitation and irradiation hardening. Results showed that Cr, Ni and Si segregate to prior austenite grain boundaries at low dose, but segregation ceases and redistribution occurs above 3 dpa. Grain boundary carbide coverage mirrors radiation-induced segregation. Irradiation induces formation of Ni-Si-Mn and Cu-rich precipitates that account for the majority of irradiation hardening. Radiation-induced segregation behavior is likely linked to the evolution of the precipitate and dislocation microstructures.

Wharry, Janelle P.; Jiao, Zhijie; Shankar, Vani; Busby, Jeremy T.; Was, Gary S.

2011-10-01

268

Bystander effects in radiation-induced genomic instability  

NASA Technical Reports Server (NTRS)

Exposure of GM10115 hamster-human hybrid cells to X-rays can result in the induction of chromosomal instability in the progeny of surviving cells. This instability manifests as the dynamic production of novel sub-populations of cells with unique cytogenetic rearrangements involving the "marker" human chromosome. We have used the comet assay to investigate whether there was an elevated level of endogenous DNA breaks in chromosomally unstable clones that could provide a source for the chromosomal rearrangements and thus account for the persistent instability observed. Our results indicate no significant difference in comet tail measurement between non-irradiated and radiation-induced chromosomally unstable clones. Using two-color fluorescence in situ hybridization we also investigated whether recombinational events involving the interstitial telomere repeat-like sequences in GM10115 cells were involved at frequencies higher than random processes would otherwise predict. Nine of 11 clones demonstrated a significantly higher than expected involvement of these interstitial telomere repeat-like sequences at the recombination junction between the human and hamster chromosomes. Since elevated levels of endogenous breaks were not detected in unstable clones we propose that epigenetic or bystander effects (BSEs) lead to the activation of recombinational pathways that perpetuate the unstable phenotype. Specifically, we expand upon the hypothesis that radiation induces conditions and/or factors that stimulate the production of reactive oxygen species (ROS). These reactive intermediates then contribute to a chronic pro-oxidant environment that cycles over multiple generations, promoting chromosomal recombination and other phenotypes associated with genomic instability.

Morgan, William F.; Hartmann, Andreas; Limoli, Charles L.; Nagar, Shruti; Ponnaiya, Brian

2002-01-01

269

Aviation-induced cirrus and radiation changes at diurnal timescales  

NASA Astrophysics Data System (ADS)

Abstract The <span class="hlt">radiative</span> forcing from aviation-<span class="hlt">induced</span> cirrus is derived from observations and models. The annual mean diurnal cycle of airtraffic in the North Atlantic region exhibits two peaks in early morning and afternoon with different peak times in the western and eastern parts of the North Atlantic region. The same "aviation fingerprint" is found in 8 years (2004-2011) of Meteosat observations of cirrus cover and OLR. The observations are related to airtraffic data with linear response models assuming the background atmosphere without aviation to be similar to that observed in the South Atlantic. The change in OLR is interpreted as aviation-<span class="hlt">induced</span> longwave <span class="hlt">radiative</span> forcing (LW RF). The data analysis suggests an LW RF of about 600-900 mW m-2 regionally. A detailed contrail cirrus model for given global meteorology and airtraffic in 2006 gives similar results. The global RF is estimated from the ratio of global and regional RF as derived from three models. The extrapolation implies about 100-160 mW m-2 global LW RF. The models show large differences in the shortwave/longwave RF-magnitude ratio. One model computes a ratio of 0.6, implying an estimate of global net RF of about 50 mW m-2 (40-80 mW m-2). Other models suggest smaller ratios, with less cooling during day, which would imply considerably larger net effects. The sensitivity of the results to the accuracy of the observations, traffic data, and models and the estimated background is discussed.</p> <div class="credits"> <p class="dwt_author">Schumann, Ulrich; Graf, Kaspar</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-03-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">270</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/12106650"> <span id="translatedtitle">Bystander effects in <span class="hlt">radiation-induced</span> genomic instability.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Exposure of GM10115 hamster-human hybrid cells to X-rays can result in the induction of chromosomal instability in the progeny of surviving cells. This instability manifests as the dynamic production of novel sub-populations of cells with unique cytogenetic rearrangements involving the "marker" human chromosome. We have used the comet assay to investigate whether there was an elevated level of endogenous DNA breaks in chromosomally unstable clones that could provide a source for the chromosomal rearrangements and thus account for the persistent instability observed. Our results indicate no significant difference in comet tail measurement between non-irradiated and <span class="hlt">radiation-induced</span> chromosomally unstable clones. Using two-color fluorescence in situ hybridization we also investigated whether recombinational events involving the interstitial telomere repeat-like sequences in GM10115 cells were involved at frequencies higher than random processes would otherwise predict. Nine of 11 clones demonstrated a significantly higher than expected involvement of these interstitial telomere repeat-like sequences at the recombination junction between the human and hamster chromosomes. Since elevated levels of endogenous breaks were not detected in unstable clones we propose that epigenetic or bystander effects (BSEs) lead to the activation of recombinational pathways that perpetuate the unstable phenotype. Specifically, we expand upon the hypothesis that <span class="hlt">radiation</span> <span class="hlt">induces</span> conditions and/or factors that stimulate the production of reactive oxygen species (ROS). These reactive intermediates then contribute to a chronic pro-oxidant environment that cycles over multiple generations, promoting chromosomal recombination and other phenotypes associated with genomic instability. PMID:12106650</p> <div class="credits"> <p class="dwt_author">Morgan, William F; Hartmann, Andreas; Limoli, Charles L; Nagar, Shruti; Ponnaiya, Brian</p> <p class="dwt_publisher"></p> <p class="publishDate">2002-07-25</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">271</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/servlets/purl/6053623"> <span id="translatedtitle"><span class="hlt">Radiation-induced</span> leukemia: Comparative studies in mouse and man</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">We now have a clear understanding of the mechanism by which <span class="hlt">radiation-induced</span> (T-cell) leukemia occurs. In irradiated mice (<span class="hlt">radiation-induced</span> thymic leukemia) and in man (acute lymphoblastic T-cell leukemia, T-ALL) the mechanism of leukemogenesis is surprisingly similar. Expressed in the most elementary terms, T-cell leukemia occurs when T-cell differentiation is inhibited by a mutation, and pre-T cells attempt but fail to differentiate in the thymus. Instead of leaving the thymus for the periphery as functional T-cells they continue to proliferate in the thymus. The proliferating pre- (pro-) T-cells constitute the (early) acute T-cell leukemia (A-TCL). This model for the mechanism of T-cell leukemogenesis accounts for all the properties of both murine and human A-TCL. Important support for the model has recently come from work by Ilan Kirsch and others, who have shown that mutations/deletions in the genes SCL (TAL), SIL, and LCK constitute primary events in the development of T-ALL, by inhibiting differentiation of thymic pre- (pro-) T-cells. This mechanism of T-cell leukemogenesis brings several specific questions into focus: How do early A-TCL cells progress to become potently tumorigenic and poorly treatable Is it feasible to genetically suppress early and/or progressed A-TCL cells What is the mechanism by which the differentiation-inhibited (leukemic) pre-T cells proliferate During the first grant year we have worked on aspects of all three questions.</p> <div class="credits"> <p class="dwt_author">Haas, M.</p> <p class="dwt_publisher"></p> <p class="publishDate">1991-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">272</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2014ApPhL.104w3109C"> <span id="translatedtitle"><span class="hlt">Radiation</span> <span class="hlt">induced</span> effects on mechanical properties of nanoporous gold foams</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">It has recently been shown that due to a high surface-to-volume ratio, nanoporous materials display <span class="hlt">radiation</span> tolerance. The abundance of surfaces, which are perfect sinks for defects, and the relation between ligament size, defect diffusion, and time combine to define a window of <span class="hlt">radiation</span> resistance [Fu et al., Appl. Phys. Lett. 101, 191607 (2012)]. Outside this window, the dominant defect created by irradiation in Au nanofoams are stacking fault tetrahedra (SFT). Molecular dynamics computer simulations of nanopillars, taken as the elemental constituent of foams, predict that SFTs act as dislocation sources <span class="hlt">inducing</span> softening, in contrast to the usual behavior in bulk materials, where defects are obstacles to dislocation motion, producing hardening. In this work we test that prediction and answer the question whether irradiation actually hardens or softens a nanofam. Ne ion irradiations of gold nanofoams were performed at room temperature for a total dose up to 4 dpa, and their mechanical behavior was measured by nanoindentation. We find that hardness increases after irradiation, a result that we analyze in terms of the role of SFTs on the deformation mode of foams.</p> <div class="credits"> <p class="dwt_author">Caro, M.; Mook, W. M.; Fu, E. G.; Wang, Y. Q.; Sheehan, C.; Martinez, E.; Baldwin, J. K.; Caro, A.</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-06-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">273</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3354559"> <span id="translatedtitle">Are Epigenetic Mechanisms Involved in <span class="hlt">Radiation-Induced</span> Bystander Effects?</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">The “non-targeted effects” of ionizing <span class="hlt">radiation</span> including bystander effects and genomic instability are unique in that no classic mutagenic event occurs in the cell showing the effect. In the case of bystander effects, cells which were not in the field affected by the <span class="hlt">radiation</span> show high levels of mutations, chromosome aberrations, and membrane signaling changes leading to what is termed “horizontal transmission” of mutations and information which may be damaging while in the case of genomic instability, generations of cells derived from an irradiated progenitor appear normal but then lethal and non-lethal mutations appear in distant progeny. This is known as “vertical transmission.” In both situations high yields of non-clonal mutations leading to distant occurrence of mutation events both in space and time. This precludes a mutator phenotype or other conventional explanation and appears to indicate a generalized form of stress-<span class="hlt">induced</span> mutagenesis which is well documented in bacteria. This review will discuss the phenomenology of what we term “non-targeted effects,” and will consider to what extent they challenge conventional ideas in genetics and epigenetics. PMID:22629281</p> <div class="credits"> <p class="dwt_author">Mothersill, Carmel; Seymour, Colin</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">274</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20040089880&hterms=genetic+transformation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dgenetic%2Btransformation"> <span id="translatedtitle"><span class="hlt">Radiation-induced</span> chromosomal instability in human mammary epithelial cells</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">Karyotypes of human cells surviving X- and alpha-irradiation have been studied. Human mammary epithelial cells of the immortal, non-tumorigenic cell line H184B5 F5-1 M/10 were irradiated and surviving clones isolated and expanded in culture. Cytogenetic analysis was performed using dedicated software with an image analyzer. We have found that both high- and low-LET <span class="hlt">radiation</span> <span class="hlt">induced</span> chromosomal instability in long-term cultures, but with different characteristics. Complex chromosomal rearrangements were observed after X-rays, while chromosome loss predominated after alpha-particles. Deletions were observed in both cases. In clones derived from cells exposed to alpha-particles, some cells showed extensive chromosome breaking and double minutes. Genomic instability was correlated to delayed reproductive death and neoplastic transformation. These results indicate that chromosomal instability is a <span class="hlt">radiation</span>-quality-dependent effect which could determine late genetic effects, and should therefore be carefully considered in the evaluation of risk for space missions.</p> <div class="credits"> <p class="dwt_author">Durante, M.; Grossi, G. F.; Yang, T. C.</p> <p class="dwt_publisher"></p> <p class="publishDate">1996-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">275</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/22149580"> <span id="translatedtitle">Hyperbaric Oxygen Therapy for <span class="hlt">Radiation-Induced</span> Cystitis and Proctitis</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">Purpose: To provide a retrospective analysis of the efficacy of hyperbaric oxygen therapy (HBOT) for treating hemorrhagic cystitis (HC) and proctitis secondary to pelvic- and prostate-only radiotherapy. Methods and Materials: Nineteen patients were treated with HBOT for <span class="hlt">radiation-induced</span> HC and proctitis. The median age at treatment was 66 years (range, 15-84 years). The range of external-beam <span class="hlt">radiation</span> delivered was 50.0-75.6 Gy. Bleeding must have been refractory to other therapies. Patients received 100% oxygen at 2.0 atmospheres absolute pressure for 90-120 min per treatment in a monoplace chamber. Symptoms were retrospectively scored according to the Late Effects of Normal Tissues-Subjective, Objective, Management, Analytic (LENT-SOMA) scale to evaluate short-term efficacy. Recurrence of hematuria/hematochezia was used to assess long-term efficacy. Results: Four of the 19 patients were lost to follow-up. Fifteen patients were evaluated and received a mean of 29.8 dives: 11 developed HC and 4 proctitis. All patients experienced a reduction in their LENT-SOMA score. After completion of HBOT, the mean LENT-SOMA score was reduced from 0.78 to 0.20 in patients with HC and from 0.66 to 0.26 in patients with proctitis. Median follow-up was 39 months (range, 7-70 months). No cases of hematuria were refractory to HBOT. Complete resolution of hematuria was seen in 81% (n = 9) and partial response in 18% (n = 2). Recurrence of hematuria occurred in 36% (n = 4) after a median of 10 months. Complete resolution of hematochezia was seen in 50% (n = 2), partial response in 25% (n = 1), and refractory bleeding in 25% (n = 1). Conclusions: Hyperbaric oxygen therapy is appropriate for <span class="hlt">radiation-induced</span> HC once less time-consuming therapies have failed to resolve the bleeding. In these conditions, HBOT is efficacious in the short and long term, with minimal side effects.</p> <div class="credits"> <p class="dwt_author">Oliai, Caspian; Fisher, Brandon; Jani, Ashish; Wong, Michael; Poli, Jaganmohan; Brady, Luther W. [Department of Radiation Oncology, Drexel University College of Medicine, Philadelphia, Pennsylvania (United States)] [Department of Radiation Oncology, Drexel University College of Medicine, Philadelphia, Pennsylvania (United States); Komarnicky, Lydia T., E-mail: lydia.komarnicky-kocher@drexelmed.edu [Department of Radiation Oncology, Drexel University College of Medicine, Philadelphia, Pennsylvania (United States)</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-11-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">276</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1991PhDT.......187K"> <span id="translatedtitle"><span class="hlt">Radiation-Induced</span> Damage to Nucleic Acid Constituents</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The objective of this research was to identify the primary free radical species produced by ionizing <span class="hlt">radiation</span> in DNA. The ultimate goal would be to use these data obtained from model compounds to analyze <span class="hlt">radiation-induced</span> damage in DNA itself. The different single crystals were studied in detail. The first was the sodium salt of guanosine-3 ^':5^' -cyclic monophosphate (cyclic GMP). The results of studies on crystals irradiated at 4.2^ circK distinguished two species. One of these species exhibited a non-exchangeable proton coupling that was characterized by ENDOR spectroscopy and shown to be sigma proton. The spin density on C8 was deduced from the ENDOR hyperfine coupling tensor and found to be 0.15. The second species also exhibited a non-exchangeable sigma proton coupling and a beta proton coupling. The spin densities on C8 and N9 were deduced from ENDOR measurements to be 0.09 and 0.36. The former is attributed to the oxidation product and the latter to the primary reduction product. These products are respectively the guanine cation and anion. The second single crystal studied was a sodium salt of 2^'-deoxyguanosine -5^'-monophosphate tetrahydrate. The ESR and ENDOR spectra obtained from this crystal after x-irradiation at 4.2^circK were complex and the paramagnetic species were tentatively identified as ionic species. The third DNA model compound studied was thymidine. Single crystal of thymidine were irradiated at 1.6^ circK and at 4.2^circ K. The lower temperature preserved a more primitive stage of the <span class="hlt">radiation</span> damage process. ENDOR measurements distinguished three paramagnetic species. The most interesting component of the paramagnetic absorption in crystals irradiated at 1.6^circK is attributed to trapped electron. These electrons are stabilized by the electrostatic fields generated by hydroxy dipoles. The hyperfine couplings between the trapped electron and the proton of these polar groups were deduced from ENDOR measurements. The ESR and ENDOR measurements described in this report were carried out DNA model compounds x-irradiated and measured at lower temperatures than reported previously. The experiments have demonstrated that an earlier stage of <span class="hlt">radiation</span> damage can sometimes be stabilized and characterized in single crystals by maintaining the sample at 1.4 ^circK. (Abstract shortened with permission of author.).</p> <div class="credits"> <p class="dwt_author">Kim, Heasook</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">277</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/20706262"> <span id="translatedtitle"><span class="hlt">Radiation-induced</span> osteosarcomas in the pediatric population</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">Purpose: <span class="hlt">Radiation-induced</span> osteosarcomas (R-OS) have historically been high-grade, locally invasive tumors with a poor prognosis. The purpose of this study was to perform a comprehensive literature review and analysis of reported cases dealing with R-OS in the pediatric population to identify the characteristics, prognostic factors, optimal treatment modalities, and overall survival of these patients. Methods and Materials: A MEDLINE/PubMed search of articles written in the English language dealing with OSs occurring after radiotherapy (RT) in the pediatric population yielded 30 studies from 1981 to 2004. Eligibility criteria included patients <21 years of age at the diagnosis of the primary cancer, cases satisfying the modified Cahan criteria, and information on treatment outcome. Factors analyzed included the type of primary cancer treated with RT, the <span class="hlt">radiation</span> dose and beam energy, the latency period between RT and the development of R-OS, and the treatment, follow-up, and final outcome of R-OS. Results: The series included 109 patients with a median age at the diagnosis of primary cancer of 6 years (range, 0.08-21 years). The most common tumors treated with RT were Ewing's sarcoma (23.9%), rhabdomyosarcoma (17.4%), retinoblastoma (12.8%), Hodgkin's disease (9.2%), brain tumor (8.3%), and Wilms' tumor (6.4%). The median <span class="hlt">radiation</span> dose was 47 Gy (range, 15-145 Gy). The median latency period from RT to the development of R-OS was 100 months (range, 36-636 months). The median follow-up after diagnosis of R-OS was 18 months (1-172 months). The 3- and 5-year cause-specific survival rate was 43.6% and 42.2%, respectively, and the 3- and 5-year overall survival rate was 41.7% and 40.2%, respectively. Variables, including age at RT, primary site, type of tumor treated with RT, total <span class="hlt">radiation</span> dose, and latency period did not have a significant effect on survival. The 5-year cause-specific and overall survival rate for patients who received treatment for R-OS involving chemotherapy alone, surgery alone, and surgery plus chemotherapy was 17.3% and 17.3%, 56.6% and 50.3%, and 71.0% and 68.3%, respectively (p < 0.0001, log-rank test). Conclusion: The type of treatment for R-OS was the most significant factor for cause-specific and overall survival. Patients who develop R-OS should be aggressively treated, because the outcome is not as dismal as once thought.</p> <div class="credits"> <p class="dwt_author">Koshy, Matthew [Department of Radiology, Division of Radiation Oncology, Baylor College of Medicine, Methodist Hospital, and Texas Children's Hospital, Houston, TX (United States); Paulino, Arnold C. [Department of Radiology, Division of Radiation Oncology, Baylor College of Medicine, Methodist Hospital, and Texas Children's Hospital, Houston, TX (United States)]. E-mail: apaulino@tmh.tmc.edu; Mai, Wei Y. [Department of Radiology, Division of Radiation Oncology, Baylor College of Medicine, Methodist Hospital, and Texas Children's Hospital, Houston, TX (United States); Teh, Bin S. [Department of Radiology, Division of Radiation Oncology, Baylor College of Medicine, Methodist Hospital, and Texas Children's Hospital, Houston, TX (United States)</p> <p class="dwt_publisher"></p> <p class="publishDate">2005-11-15</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">278</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/21608123"> <span id="translatedtitle">Deep Level Transient Spectroscopy Technique to Analyze <span class="hlt">Radiation</span> <span class="hlt">Induced</span> Defects in Power Transistors</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">Deep Level Transient Spectroscopy (DLTS) technique is useful tool to study process and <span class="hlt">radiation</span> <span class="hlt">induced</span> defects in semiconductor materials and devices. The different types of <span class="hlt">radiation</span> <span class="hlt">induced</span> trap levels in the collector-base depletion region of the transistors were studied by DLTS technique.</p> <div class="credits"> <p class="dwt_author">Prakash, A. P. Gnana [Department of Studies in Physics, University of Mysore, Manasagangotri, Mysore, Karnataka-570006 (India)</p> <p class="dwt_publisher"></p> <p class="publishDate">2011-07-15</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">279</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/39916759"> <span id="translatedtitle"><span class="hlt">Radiation-induced</span> stress change in polymers during irradiation by electrons</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The goal of this study is to experimentally validate equations previously used to describe a <span class="hlt">radiation-induced</span> stress change (RSC) in polymers. <span class="hlt">Radiation-induced</span> creep is due to the freeing of volumes of the material with the breakdown of a bond. With an increase in molecular mobility, the contribution of single defects to creep may be an appreciable fraction of the contribution</p> <div class="credits"> <p class="dwt_author">E. A. Barbashev; V. A. Bogatov; V. I. Kozin; B. I. Panshin</p> <p class="dwt_publisher"></p> <p class="publishDate">1986-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">280</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/29243910"> <span id="translatedtitle">Early hyperbaric oxygen therapy improves outcome for <span class="hlt">radiation-induced</span> hemorrhagic cystitis</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">ObjectivesTo assess the clinical factors that affect the efficacy of hyperbaric oxygen (HBO2) therapy in treating <span class="hlt">radiation-induced</span> hemorrhagic cystitis. HBO2 therapy is an effective treatment for <span class="hlt">radiation-induced</span> hemorrhagic cystitis, with reported response rates ranging from 76% to 100%.</p> <div class="credits"> <p class="dwt_author">Kian Tai Chong; Neil B. Hampson; John M. Corman</p> <p class="dwt_publisher"></p> <p class="publishDate">2005-01-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_13");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a onClick='return showDiv("page_3");' href="#">3</a> <a onClick='return showDiv("page_4");' 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class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_14");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a onClick='return showDiv("page_3");' href="#">3</a> <a onClick='return showDiv("page_4");' href="#">4</a> <a onClick='return showDiv("page_5");' href="#">5</a> <a onClick='return showDiv("page_6");' href="#">6</a> <a onClick='return showDiv("page_7");' href="#">7</a> <a onClick='return showDiv("page_8");' href="#">8</a> <a onClick='return showDiv("page_9");' href="#">9</a> <a onClick='return showDiv("page_10");' href="#">10</a> <a onClick='return showDiv("page_11");' href="#">11</a> <a onClick='return showDiv("page_12");' href="#">12</a> <a onClick='return showDiv("page_13");' href="#">13</a> <a onClick='return showDiv("page_14");' href="#">14</a> <a style="font-weight: bold;">15</a> <a onClick='return showDiv("page_16");' href="#">16</a> <a onClick='return showDiv("page_17");' href="#">17</a> <a onClick='return showDiv("page_18");' href="#">18</a> <a onClick='return showDiv("page_19");' href="#">19</a> <a onClick='return showDiv("page_20");' href="#">20</a> <a onClick='return showDiv("page_21");' href="#">21</a> <a onClick='return showDiv("page_22");' href="#">22</a> <a onClick='return showDiv("page_23");' href="#">23</a> <a onClick='return showDiv("page_24");' href="#">24</a> <a onClick='return showDiv("page_25");' href="#">25</a> </span> </span> <a id="NextPageLink" onclick='return showDiv("page_16");' href="#" title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">281</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2834342"> <span id="translatedtitle">Androgens <span class="hlt">induce</span> oxidative stress and <span class="hlt">radiation</span> resistance in prostate cancer cells though NADPH oxidase</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Androgen deprivation therapy (ADT) facilitates the response of prostate cancer (PC) to <span class="hlt">radiation</span>. Androgens have been shown to <span class="hlt">induce</span> elevated basal levels of reactive oxygen species (ROS) in PC, leading to adaptation to <span class="hlt">radiation-induced</span> cytotoxic oxidative stress. Here, we show that androgens increase the expression of p22phox and gp91phox subunits of NADPH oxidase (NOX) and ROS production by NOX2 and NOX4 in PC. Pre-<span class="hlt">radiation</span> treatment of 22Rv1 human PC cells with NOX inhibitors sensitize the cells to <span class="hlt">radiation</span> similarly to ADT, suggesting that their future usage may spare the need for adjuvant ADT in PC patients undergoing <span class="hlt">radiation</span>. PMID:19546883</p> <div class="credits"> <p class="dwt_author">Lu, J P; Monardo, L; Bryskin, I; Hou, Z F; Trachtenberg, J; Wilson, B C; Pinthus, J H</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">282</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2012AIPC.1459...51P"> <span id="translatedtitle">Poly lactic acid based foams prepared via thermally <span class="hlt">induced</span> phase separation (TIPS): A method to tune the <span class="hlt">crystallinity</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Blends of Poly-L-Lactic Acid (PLLA) with two Poly-Lactic Acid (PLA) in different proportions (90/10 and 70/30) were utilized in order to produce biodegradable and biocompatible scaffolds for soft tissue engineering applications. The scaffolds were produced via thermally <span class="hlt">induced</span> phase separation (TIPS) starting from ternary systems where dioxane was the solvent and water the non-solvent. Morphology was evaluated by Scanning Electron Microscopy (average pore size and interconnection). Moreover a DSC analysis was carried out on the as-obtained scaffold in order to obtain information about theirs thermal properties (enthalpy of melt and crystallization). The results showed that is possible to prepare scaffolds of PLLA/PLA via TIPS. Moreover, the PLA seems to influences the TIPS process in terms of demixing temperatures. The data confirm that the morphology and the mechanical properties of the scaffold can be tuned, starting from PLLA blends and using PLA with different molecular weights.</p> <div class="credits"> <p class="dwt_author">Pavia, Francesco Carf?; La Carrubba, Vincenzo; Brucato, Valerio</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-07-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">283</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/5956570"> <span id="translatedtitle">Effects of subdiaphragmatic vagotomy on the acquisition of a <span class="hlt">radiation-induced</span> conditioned taste aversion</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">The effect of subdiaphragmatic vagotomy on the acquisition of a <span class="hlt">radiation-induced</span> taste aversion was examined to assess the importance of the vagus nerve in transmitting information on the peripheral toxicity of <span class="hlt">radiation</span> to the brain. Vagotomy had no effect on taste aversion learning, consistent with reports using other toxins. The data support the involvement of a blood-borne factor in the acquisition of taste aversion <span class="hlt">induced</span> by ionizing <span class="hlt">radiation</span>.</p> <div class="credits"> <p class="dwt_author">Hunt, W.A.; Rabin, B.M.; Lee, J.</p> <p class="dwt_publisher"></p> <p class="publishDate">1987-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">284</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/1633310"> <span id="translatedtitle">In situ measurement of refractive index changes <span class="hlt">induced</span> by gamma <span class="hlt">radiation</span> in germanosilicate fibers</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">We propose a technique to measure in situ the refractive index changes <span class="hlt">induced</span> by ionizing <span class="hlt">radiation</span> in single-mode optical fibers. This change can be derived from the channel drift appearing in narrow channel wavelength-division-multiplexing couplers exposed to gamma <span class="hlt">radiation</span>. We measured a <span class="hlt">radiation-induced</span> refractive index change of about 5 10-6\\/kGy[H2O] at low doses and 5 10-7\\/kGy[H2O] at higher doses. No</p> <div class="credits"> <p class="dwt_author">A. Fernandez Fernandez; B. Brichard; F. Berghmans</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">285</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2014JCrGr.405..131T"> <span id="translatedtitle">Defect formation <span class="hlt">induced</span> by seed-joints during directional solidification of quasi-mono-<span class="hlt">crystalline</span> silicon ingots</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">In this work, the growth behavior inside and above seed gaps during directional solidification of monocrystalline lab-scale silicon ingots was investigated. It will be shown that the silicon melt fills the gaps rapidly and monocrystalline growth starts in most cases at the seed side walls toward the gap center. During this process, dislocations were <span class="hlt">induced</span> at the seed edges and in the gap center by the thermal shock caused by the hot melt and the coalescence of the two growth interfaces, respectively. The dislocations originating from the gap are propagating more or less parallel to the growth axis toward the top of the crystal. These dislocation bundles fan out in dependence of the growth height and axial seed orientation, respectively. It was found that <1 0 0> is the most suitable growth direction in comparison to <1 1 1> and <1 1 0> to avoid defect clusters above the seed gaps which is probably due to the orientation of the preferential glide systems.</p> <div class="credits"> <p class="dwt_author">Trempa, M.; Reimann, C.; Friedrich, J.; Müller, G.; Krause, A.; Sylla, L.; Richter, T.</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-11-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">286</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/10629615"> <span id="translatedtitle">Nuclear scintigraphic assessment of <span class="hlt">radiation-induced</span> intestinal dysfunction.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary"><span class="hlt">Radiation-induced</span> damage to the intestine can be measured by abnormalities in the absorption of various nutrients. Changes in intestinal absorption occur after irradiation because of loss of the intestinal absorptive surface and a consequent decrease in active transport. In our study, the jejunal absorption of (99m)Tc-pertechnetate, an actively transported gamma-ray emitter, was assessed in C3H/Kam mice given total-body irradiation with doses of 4, 6, 8 and 12.5 Gy and correlated with morphological changes in the intestinal epithelium. The absorption of (99m)Tc-pertechnetate from the intestinal lumen into the circulation was studied with a dynamic gamma-ray-scintigraphy assay combined with a multichannel analyzer to record the radiometry data automatically in a time-dependent regimen. The resulting radioactivity-time curves obtained for irradiated animals were compared to those for control animals. A dose-dependent decrease in absorptive function was observed 3.5 days after irradiation. The mean absorption rate was reduced to 78.8 +/- 9.3% of control levels in response to 4 Gy total-body irradiation (mean +/- SEM tracer absorption lifetime was 237 +/- 23 s compared to 187 +/- 12 s in nonirradiated controls) and to 28.3 +/- 3.7% in response to 12.5 Gy (660 +/- 76 s). The decrease in absorption of (99m)Tc-pertechnetate at 3.5 days after irradiation correlated strongly (P < 0.001) with TBI dose, with the number of cells per villus, and with the percentage of cells in the crypt compartment that were apoptotic or mitotic. A jejunal microcolony assay showed no loss of crypts and hence no measured dose-response effects after 4, 6 or 8 Gy TBI. These results show that dynamic enteroscintigraphy with sodium (99m)Tc-pertechnetate is a sensitive functional assay for rapid evaluation of <span class="hlt">radiation-induced</span> intestinal damage in the clinically relevant dose range and has a cellular basis. PMID:10629615</p> <div class="credits"> <p class="dwt_author">Kirichenko, A V; Mason, K A; Straume, M; Teates, C D; Rich, T A</p> <p class="dwt_publisher"></p> <p class="publishDate">2000-02-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">287</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/51174712"> <span id="translatedtitle">Layout-Related Stress Effects on <span class="hlt">Radiation-Induced</span> Leakage Current</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The effects of shallow-trench-isolation-<span class="hlt">induced</span> mechanical stress on <span class="hlt">radiation-induced</span> off-state leakage current are reported in 90-nm NMOS devices. The <span class="hlt">radiation-induced</span> leakage current increases with increasing active device-to-isolation spacing. The leakage current also depends on channel width; narrow devices exhibit less leakage before irradiation, but more after irradiation. These geometrical factors affect the mechanical stress in the device, which impact the dopant</p> <div class="credits"> <p class="dwt_author">Nadia Rezzak; Ronald D. Schrimpf; Michael L. Alles; En Xia Zhang; Daniel M. Fleetwood; Yanfeng Albert Li</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">288</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/20486661"> <span id="translatedtitle">Sodium bicarbonate <span class="hlt">induces</span> <span class="hlt">crystalline</span> wax generation, activates host-resistance, and increases imazalil level in rind wounds of oranges, improving the control of green mold during storage.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Imazalil (IMZ) was quantified in the flavedo and albedo (Citrus fruits outer and inner tissue of the exocarp) of wounded and unwounded Valencia L. Olinda oranges following a 2 min immersion at 25 degrees C in 50, 100, or 250 microg mL(-1) of the fungicide mixture with or without 3% sodium bicarbonate (SBC). The addition of SBC significantly reduced the decay incidence throughout 30 d of storage at 10 degrees C with 95% RH and 6 d of simulated marketing period at 25 degrees C and 75% RH. In unwounded oranges, IMZ uptake was not changed by the coapplication of SBC, and the fungicide was predominantly recovered in the flavedo. To the contrary, in the albedo of wounded fruit, the residue level increased by about 6-fold when the fungicide was applied with SBC. When SBC was coapplied to wounded fruit, the phytoalexin scoparone was <span class="hlt">induced</span> in the albedo and the accumulation was not affected by IMZ. When fruit was treated with SBC, scanning electron microscopy observations evidenced a production of <span class="hlt">crystalline</span> wax patches with branched stripes and the magnitude was positively correlated to the salt concentration in the mixture. The generation as fast as 24 h post-treatment, and the different morphology of the new wax suggests a displacement of intracuticular waxes which can affect the fungicide sorption and diffusion coefficient into the rind. PMID:20486661</p> <div class="credits"> <p class="dwt_author">Dore, Antonio; Molinu, Maria Giovanna; Venditti, Tullio; D'Hallewin, Guy</p> <p class="dwt_publisher"></p> <p class="publishDate">2010-06-23</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">289</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2012JKPS...61.1732Y"> <span id="translatedtitle">Comprehensive study of the surface morphology evolution <span class="hlt">induced</span> by thermal annealing in single-<span class="hlt">crystalline</span> ZnO Films and ZnO bulks</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">We report on the evolution of the surface morphology <span class="hlt">induced</span> by thermal annealing in N2 ambient over a wide temperature range of 500-1200 °C in single-<span class="hlt">crystalline</span> ZnO films and ZnO bulks. The surface morphology is seriously changed by the annealing temperature, and the evolution can be categorized into three regions: island growth, island agglomeration, and pit formation. Island growth at low temperatures below 700 °C, is ascribed to the atomic migration to reduce surface energy, which causes surface roughening. Island agglomeration at intermediate temperatures of 700-900 °C is ascribed to the migration and the evaporation of surface atoms, which causes surface flattening. Pit formation at high temperatures above 900 °C is ascribed to the atomic evaporation by high vapor pressure, which causes surface destruction. On the other hand, the bulk lattice is continuously improved with increasing annealing temperature in the temperature regions before the surface-destruction region, which is attributed to the reduction in the numbers of point and line defects caused by recrystallization. As a result, the best surface morphology and the best bulk lattice are obtained at an annealing temperature of 900 °C. The common surface-morphology evolution of ZnO films and ZnO bulks with increasing annealing temperature can be summarized using the three steps of surface roughening by island growth, surface flattening by island agglomeration, and surface destruction by pit formation.</p> <div class="credits"> <p class="dwt_author">Yoon, N.; Oh, D. C.; Ko, H. J.; Lim, D. S.; Hong, S. K.; Yao, T.</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-11-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">290</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/12050596"> <span id="translatedtitle">[<span class="hlt">Crystalline</span> polymorphism of eflucimibe].</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">The importance, in therapeutics, of the concept of bioavailability and on-going quality research in the formulation of a drug has prompted us to examine the <span class="hlt">crystalline</span> polymorphism of eflucimibe as from the research phase. This study has been carried out by re-crystallization of the product in organic solvents having a different polarity in a variety of experimental temperature and pressure conditions, then, subsequently, by re-cooling the previously dissolved substance. The analytical methods applied to identify and then describe the polymorphic forms are thermogravimetry analysis (TGA), differential scanning calorimetry (DSC), X-ray powder diffraction from synchrotron <span class="hlt">radiation</span> (XRPD), infrared spectrometry (IR), solid-state nuclear magnetic resonance spectrometry (SSNMR) and lastly maximum solubility measurements. By means of XRPD, two polymorphic forms called A and B have been clearly identified at ambient temperature. These two <span class="hlt">crystalline</span> forms were obtained in a reproducible way, then described by DSC, XRPD, IR and SSNMR. Differential scanning calorimetry analysis has shown for polymorphic form A two endothermic phenomena with low energy at about 35 masculine and 118 degrees C attributed by XRDP to conformational polymorphism. The complex endothermic event that extends between 75 masculine and 105 degrees C appears to correspond to successive alterations of a lamellar structure. The solid-solid transition observed at 110 degrees C is due to a change of <span class="hlt">crystalline</span> phase, then the melting point occurring at about 130 degrees C. For form B, two changes of <span class="hlt">crystalline</span> phase are clearly observed at about 80 masculine and 120 degrees C. The reversibility of these changes was observed by thermomicroscopy in polarized light. Form A, which is less soluble in absolute ethanol than form B, is the more stable thermodynamically in the temperature range from 25 masculine to 50 degrees C where the data have been obtained. The Van't Hoff diagram layout for each polymorphic form appears to reveal an A<-->B transition temperature in a temperature range lower than 25 degrees C. This study, undertaken as from the research phase, has enabled us to highlight the polymorphism of this new chemical entity by means of XRDP by explaining the nature of the endothermic phenomena observed by DSC, and lastly identify the thermodynamically more stable polymorphic form, thus contributing to a better knowledge of this future drug. PMID:12050596</p> <div class="credits"> <p class="dwt_author">Ribet, J P; Pena, R; Chauvet, A; Patoiseau, J F; Autin, J M; Segonds, R; Basquin, M; Autret, J M</p> <p class="dwt_publisher"></p> <p class="publishDate">2002-05-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">291</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/60344618"> <span id="translatedtitle"><span class="hlt">Radiation-induced</span> esophageal injury: A spectrum from esophagitis to cancer</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary"><span class="hlt">Radiation</span> esophagitis is a common but frequently unrecognized complication of therapeutic <span class="hlt">radiation</span> to the neck, chest, or mediastinum. The spectrum of injury ranges from acute self-limited esophagitis to life-threatening esophageal perforation. Complications such as stricture or primary esophageal cancer may occur many years after irradiation, and their linkage to <span class="hlt">radiation</span> may not be considered. Five cases of <span class="hlt">radiation-induced</span> injury are</p> <div class="credits"> <p class="dwt_author">A. Vanagunas; P. Jacob; E. Olinger</p> <p class="dwt_publisher"></p> <p class="publishDate">1990-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">292</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3715464"> <span id="translatedtitle">Effect of Epicatechin against <span class="hlt">Radiation-Induced</span> Oral Mucositis: In Vitro and In Vivo Study</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Purpose <span class="hlt">Radiation-induced</span> oral mucositis limits the delivery of high-dose <span class="hlt">radiation</span> to head and neck cancer. This study investigated the effectiveness of epicatechin (EC), a component of green tea extracts, on <span class="hlt">radiation-induced</span> oral mucositis in vitro and in vivo. Experimental Design The effect of EC on <span class="hlt">radiation-induced</span> cytotoxicity was analyzed in the human keratinocyte line HaCaT. <span class="hlt">Radiation-induced</span> apoptosis, change in mitochondrial membrane potential (MMP), reactive oxygen species (ROS) generation and changes in the signaling pathway were investigated. In vivo therapeutic effects of EC for oral mucositis were explored in a rat model. Rats were monitored by daily inspections of the oral cavity, amount of oral intake, weight change and survival rate. For histopathologic evaluation, hematoxylin-eosin staining and TUNEL staining were performed. Results EC significantly inhibited <span class="hlt">radiation-induced</span> apoptosis, change of MMP, and intracellular ROS generation in HaCaT cells. EC treatment markedly attenuated the expression of p-JNK, p-38, and cleaved caspase-3 after irradiation in the HaCaT cells. Rats with <span class="hlt">radiation-induced</span> oral mucositis showed decreased oral intake, weight and survival rate, but oral administration of EC significantly restored all three parameters. Histopathologic changes were significantly decreased in the EC-treated irradiated rats. TUNEL staining of rat oral mucosa revealed that EC treatment significantly decreased <span class="hlt">radiation-induced</span> apoptotic cells. Conclusions This study suggests that EC significantly inhibited <span class="hlt">radiation-induced</span> apoptosis in keratinocytes and rat oral mucosa and may be a safe and effective candidate treatment for the prevention of <span class="hlt">radiation-induced</span> mucositis. PMID:23874895</p> <div class="credits"> <p class="dwt_author">Kang, Sung Un; Kim, Jang Hee; Oh, Young-Taek; Park, Keun Hyung; Kim, Chul-Ho</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">293</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20040087533&hterms=Cytology&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DCytology"> <span id="translatedtitle">Ionizing <span class="hlt">radiation</span> <span class="hlt">induces</span> heritable disruption of epithelial cell interactions</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">Ionizing <span class="hlt">radiation</span> (IR) is a known human breast carcinogen. Although the mutagenic capacity of IR is widely acknowledged as the basis for its action as a carcinogen, we and others have shown that IR can also <span class="hlt">induce</span> growth factors and extracellular matrix remodeling. As a consequence, we have proposed that an additional factor contributing to IR carcinogenesis is the potential disruption of critical constraints that are imposed by normal cell interactions. To test this hypothesis, we asked whether IR affected the ability of nonmalignant human mammary epithelial cells (HMEC) to undergo tissue-specific morphogenesis in culture by using confocal microscopy and imaging bioinformatics. We found that irradiated single HMEC gave rise to colonies exhibiting decreased localization of E-cadherin, beta-catenin, and connexin-43, proteins necessary for the establishment of polarity and communication. Severely compromised acinar organization was manifested by the majority of irradiated HMEC progeny as quantified by image analysis. Disrupted cell-cell communication, aberrant cell-extracellular matrix interactions, and loss of tissue-specific architecture observed in the daughters of irradiated HMEC are characteristic of neoplastic progression. These data point to a heritable, nonmutational mechanism whereby IR compromises cell polarity and multicellular organization.</p> <div class="credits"> <p class="dwt_author">Park, Catherine C.; Henshall-Powell, Rhonda L.; Erickson, Anna C.; Talhouk, Rabih; Parvin, Bahram; Bissell, Mina J.; Barcellos-Hoff, Mary Helen; Chatterjee, A. (Principal Investigator)</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">294</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013JaJAP..52gHF21N"> <span id="translatedtitle">Ultrasonic Measurement of Microdisplacement <span class="hlt">Induced</span> by Acoustic <span class="hlt">Radiation</span> Force</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Quantitative evaluation of human skin aging is achieved by measuring the viscoelasticity of the skin. In the present study, microdisplacement <span class="hlt">induced</span> by acoustic <span class="hlt">radiation</span> force (ARF) is quantitatively measured by high-frequency ultrasonography (HFUS) and the result is confirmed by laser-Doppler velocimetry (LDV). Poly(vinyl alcohol) (PVA) with 1% cellulose particles was used as the biological phantom. A concave piezoelectric zirconate titanate (PZT) transducer with a diameter and focal length of 3 cm was used as an applicator to generate ARF. Microdisplacement at each depth of PVA was measured by the phased tracking method at 100 MHz of ultrasound with a repetition rate of 2000 Hz. When 80 tone-burst pulses were applied, the displacement measured by HFUS was 9 µm and the same result was obtained by LDV. As the displacement at each depth of PVA is measurable using ARF and the HFUS system, the system could be applied to measuring the viscoelasticity of the layered structure of the human skin.</p> <div class="credits"> <p class="dwt_author">Nagaoka, Ryo; Izumi, Takuya; Komatsu, Yosuke; Kobayashi, Kazuto; Saijo, Yoshifumi</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-07-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">295</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/9032853"> <span id="translatedtitle"><span class="hlt">Radiation-induced</span> edema after Gamma Knife treatment for meningiomas.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">A retrospective study was performed to analyze some parameters in a consecutive series of 35 Gamma Knife treatments in 34 patients with benign meningiomas. The minimum dose to the tumors was never less than 12 Gy. The follow-up period was from 1 to 3 years. A semiquantitative method of tumor volume assessment was used to measure the tumor response to treatment. The presence and clinical significance of postradiation edema were noted. Even in this short follow-up period, 11 of the 35 tumors were reduced in volume. No tumors increased in size. Edema developed preferentially in nonbasal tumors, especially those around the midline and sagittal sinus. In all but one case where <span class="hlt">radiation-induced</span> edema was observed was the margin tumor dose 18 Gy or more. It is suggested that doses of 18 Gy or more should probably be avoided in the Gamma Knife treatment of meningiomas and that the greatest care should be taken in selecting non-skull base tumors for this form of treatment. PMID:9032853</p> <div class="credits"> <p class="dwt_author">Ganz, J C; Schröttner, O; Pendl, G</p> <p class="dwt_publisher"></p> <p class="publishDate">1996-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">296</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2014Nanos...6.7805L"> <span id="translatedtitle">Oxygen vacancy <span class="hlt">induced</span> selective silver deposition on the {001} facets of BiOCl single-<span class="hlt">crystalline</span> nanosheets for enhanced Cr(vi) and sodium pentachlorophenate removal under visible light</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">We demonstrate that the high oxygen density characteristic of BiOCl {001} facets ensures the fast generation of oxygen vacancies in ethylene glycol under microwave irradiation, resulting in in situ nucleation and growth of Ag on the {001} facets of BiOCl single-<span class="hlt">crystalline</span> nanosheets. The resulting Ag selectively deposited BiOCl single-<span class="hlt">crystalline</span> nanosheets exhibit much higher reactivity and stability on both Cr(vi) reduction and sodium pentachlorophenate oxidation than the randomly deposited counterparts under visible light because of the tight contact between Ag and the {001} facets of BiOCl arisen from oxygen vacancy <span class="hlt">induced</span> selective silver deposition.We demonstrate that the high oxygen density characteristic of BiOCl {001} facets ensures the fast generation of oxygen vacancies in ethylene glycol under microwave irradiation, resulting in in situ nucleation and growth of Ag on the {001} facets of BiOCl single-<span class="hlt">crystalline</span> nanosheets. The resulting Ag selectively deposited BiOCl single-<span class="hlt">crystalline</span> nanosheets exhibit much higher reactivity and stability on both Cr(vi) reduction and sodium pentachlorophenate oxidation than the randomly deposited counterparts under visible light because of the tight contact between Ag and the {001} facets of BiOCl arisen from oxygen vacancy <span class="hlt">induced</span> selective silver deposition. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr01315h</p> <div class="credits"> <p class="dwt_author">Li, Hao; Zhang, Lizhi</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-06-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">297</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.nerc-essc.ac.uk/~rpa/PAPERS/Haywood09JGR.pdf"> <span id="translatedtitle">A case study of the <span class="hlt">radiative</span> forcing of persistent contrails evolving into contrail-<span class="hlt">induced</span> cirrus</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/epsearch/">E-print Network</a></p> <p class="result-summary">A case study of the <span class="hlt">radiative</span> forcing of persistent contrails evolving into contrail-<span class="hlt">induced</span> cirrus due to a distinct pattern of persistent contrails that form into contrail-<span class="hlt">induced</span> cirrus near and over of the contrail-<span class="hlt">induced</span> cirrus is tracked using a number of high-resolution polar orbiting and lower</p> <div class="credits"> <p class="dwt_author">Allan, Richard P.</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">298</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/30546285"> <span id="translatedtitle">HYPERBARIC OXYGEN THERAPY FOR <span class="hlt">RADIATION</span> <span class="hlt">INDUCED</span> HEMORRHAGIC CYSTITIS</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Purpose<span class="hlt">Radiation</span> therapy has been used successfully to treat pelvic malignancy but morbidity from hemorrhagic cystitis remains a major long-term sequela in 1 to 2% of patients. Obliterative endarteritis secondary to ionizing <span class="hlt">radiation</span> leads to tissue hypoxia and poor healing. Hyperbaric oxygen therapy has been demonstrated to improve angiogenesis and promote healing in <span class="hlt">radiation</span> injured tissue, including the bladder. We describe</p> <div class="credits"> <p class="dwt_author">RANJIV MATHEWS; NATARAJAN RAJAN; LAURA JOSEFSON; ENRICO CAMPORESI; ZAHI MAKHULI</p> <p class="dwt_publisher"></p> <p class="publishDate">1999-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">299</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1993STIN...9431148B"> <span id="translatedtitle">Transient <span class="hlt">radiation-induced</span> absorption in the materials for a GSGG laser</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Materials used in the optical elements of a 1,061 m GSGG (gadolinium scandium gallium garnet) laser have been tested for transient <span class="hlt">radiation-induced</span> absorption. The transient <span class="hlt">radiation-induced</span> absorption in KK1, Schott S7005 and S7010, and M382 glasses have been determined for discrete wavelengths in the range 440-750 nm. Also, the transient <span class="hlt">radiation-induced</span> absorption in 'pure' and MgO doped LiNbO3 has been measured at 1,061 nm. Mathematical expressions composed of exponentials are fitted to the data.</p> <div class="credits"> <p class="dwt_author">Brannon, P. J.</p> <p class="dwt_publisher"></p> <p class="publishDate">1993-11-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">300</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/servlets/purl/10115362"> <span id="translatedtitle">Transient <span class="hlt">radiation-induced</span> absorption in the materials for a GSGG laser</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">Materials used in the optical elements of a 1,061 m GSGG (gadolinium scandium gallium garnet) laser have been tested for transient <span class="hlt">radiation-induced</span> absorption. The transient <span class="hlt">radiation-induced</span> absorption in KK1, Schott S7005 and S7010, and M382 glasses have been determined for discrete wavelengths in the range 440--750 nm. Also, the transient <span class="hlt">radiation-induced</span> absorption in {open_quotes}pure{close_quotes} and MgO doped LiNbO{sub 3} has been measured at 1,061 nm. Mathematical expressions composed of exponentials are fitted to the data.</p> <div class="credits"> <p class="dwt_author">Brannon, P.J.</p> <p class="dwt_publisher"></p> <p class="publishDate">1993-11-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_14");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return 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title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">301</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2002PhDT.......132P"> <span id="translatedtitle"><span class="hlt">Radiation-induced</span> changes affecting polyester based polyurethane binder</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The application of thermoplastic polyurethane elastomers as binders in the high energy explosives particularly when used in weapons presents a significantly complex and challenging problem due to the impact of the aging of this polymer on the useful service life of the explosive. In this work, the effects of <span class="hlt">radiation</span> on the aging of the polyester based polyurethane were investigated using both electron beam and gamma irradiation at various dose rates in the presence and absence of oxygen. It was found by means of GPC that, in the presence and absence of oxygen, the poly (ester urethane) primarily undergoes cross-linking, by means of a carbon-centered secondary alkyl radical. It was also concluded that the polymer partially undergoes scission of the backbone of the main chain at C-O, N-C, and C-C bonds. Substantial changes in the conditions of irradiation and in dose levels did not affect the cross-linking and scission yields. Experiments were also performed with EPR spectroscopy for the purpose of identifying the initial carbon-centered free radicals and for studying the decay mechanisms of these radicals. It was found that the carbon-centered radical which is produced via C-C scission (primary alkyl radical) is rapidly converted to a long-lived allylic species at higher temperatures; more than 80% radicals are converted to allyl species in 2.5 hours. In the presence of oxygen, the allyl radical undergoes a fast reaction to produce a peroxyl radical; this radical decays with a 1.7 hour half-life by pseudo first-order kinetics to negligible levels in 13 hours. FTIR measurements were conducted to identify the <span class="hlt">radiation-induced</span> changes to the functional groups in the polyester polyurethane. These measurements show an increase in carbonyl, amine and carboxylic groups as a result of reaction of H atoms with R-C-O·, ·NH-R and R-COO·. The FTIR results also demonstrate the production of the unsaturation resulting from hydrogen atom transfer during intrachain conversion of the primary alkyl radical to the allyl species, prompt trans-vinylene production in tetramethylene units, and hydrogen atom abstraction by alkyl radicals on neighboring chains. The production of unsaturation is substantiated by the EPR studies. Finally, a free radical mechanism is proposed for the production of cross-linking in polyester polyurethane.</p> <div class="credits"> <p class="dwt_author">Pierpoint, Sujita Basi</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">302</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3974334"> <span id="translatedtitle">Harmonic Tracking of Acoustic <span class="hlt">Radiation</span> Force <span class="hlt">Induced</span> Displacements</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Ultrasound-based elasticity imaging methods rely upon accurate estimates of tissue deformation to characterize the mechanical properties of soft tissues. These methods are corrupted by clutter, which can bias and/or increase variance in displacement estimates. Harmonic imaging methods are routinely used for clutter suppression and improved image quality in conventional B-mode ultrasound, but have not been utilized in ultrasound-based elasticity imaging methods. We introduce a novel, fully-sampled pulse inversion harmonic method for tracking tissue displacements that corrects the loss in temporal sampling frequency associated with conventional pulse inversion techniques. The method is implemented with Acoustic <span class="hlt">Radiation</span> Force Impulse (ARFI) imaging to monitor the displacements <span class="hlt">induced</span> by an impulsive acoustic <span class="hlt">radiation</span> force excitation. Custom pulse sequences were implemented on a diagnostic ultrasound scanner to collect spatially-matched fundamental and harmonic information within a single acquisition. B-mode and ARFI images created from fundamental data collected at 4 MHz and 8 MHz are compared with 8 MHz harmonic images created using a bandpass filter approach and the fully sampled pulse inversion method. In homogeneous, tissue-mimicking phantoms, where no visible clutter was observed, there was little difference in the axial displacements, estimated jitter, and normalized cross-correlation among the fundamental and harmonic tracking methods. The similarity of the lower and higher frequency methods suggests that any improvement due to the increased frequency of the harmonic components is negligible. The harmonic tracking methods demonstrated a marked improvement in B-mode and ARFI image quality of in vivo carotid arteries. Improved feature detection and decreased variance in estimated displacements were observed in the arterial walls of harmonic ARFI images, especially in the pulse inversion harmonic ARFI images. Within the lumen, the harmonic tracking methods improved the discrimination of the blood–vessel interface, making it easier to visualize plaque boundaries. Improvements in harmonic ARFI images in vivo were consistent with suppressed clutter supported by improved contrast and CNR in the matched harmonic B-mode images compared to the fundamental B-mode images. These results suggest that harmonic tracking methods can improve the clinical utility and diagnostic accuracy of ultrasound-based elasticity imaging methods. PMID:24158290</p> <div class="credits"> <p class="dwt_author">Doherty, Joshua R.; Dahl, Jeremy J.; Trahey, Gregg E.</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">303</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20040087647&hterms=GENES&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DGENES"> <span id="translatedtitle"><span class="hlt">Radiation-induced</span> gene expression in the nematode Caenorhabditis elegans</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">We used the nematode C. elegans to characterize the genotoxic and cytotoxic effects of ionizing <span class="hlt">radiation</span> in a simple animal model emphasizing the unique effects of charged particle <span class="hlt">radiation</span>. Here we demonstrate by RT-PCR differential display and whole genome microarray hybridization experiments that gamma rays, accelerated protons and iron ions at the same physical dose lead to unique transcription profiles. 599 of 17871 genes analyzed (3.4%) showed differential expression 3 hrs after exposure to 3 Gy of <span class="hlt">radiation</span>. 193 were up-regulated, 406 were down-regulated and 90% were affected only by a single species of <span class="hlt">radiation</span>. A novel statistical clustering technique identified the regulatory relationships between the <span class="hlt">radiation</span>-modulated genes and showed that genes affected by each <span class="hlt">radiation</span> species were associated with unique regulatory clusters. This suggests that independent homeostatic mechanisms are activated in response to <span class="hlt">radiation</span> exposure as a function of track structure or ionization density.</p> <div class="credits"> <p class="dwt_author">Nelson, Gregory A.; Jones, Tamako A.; Chesnut, Aaron; Smith, Anna L.</p> <p class="dwt_publisher"></p> <p class="publishDate">2002-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">304</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/servlets/purl/770807"> <span id="translatedtitle">Synchrotron-<span class="hlt">Radiation</span> <span class="hlt">Induced</span> X-Ray Emission (SRIXE)</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">Elemental analysis using emission of characteristic x rays is a well-established scientific method. The success of this analytical method is highly dependent on the properties of the source used to produce the x rays. X-ray tubes have long existed as a principal excitation source, but electron and proton beams have also been employed extensively. The development of the synchrotron <span class="hlt">radiation</span> x-ray source that has taken place during the past 40 years has had a major impact on the general field of x-ray analysis. Even tier 40 years, science of x-ray analysis with synchrotron x-ray beams is by no means mature. Improvements being made to existing synchrotron facilities and the design and construction of new facilities promise to accelerate the development of the general scientific use of synchrotron x-ray sources for at least the next ten years. The effective use of the synchrotron source technology depends heavily on the use of high-performance computers for analysis and theoretical interpretation of the experimental data. Fortunately, computer technology has advanced at least as rapidly as the x-ray technology during the past 40 years and should continue to do so during the next decade. The combination of these technologies should bring about dramatic advances in many fields where synchrotron x-ray science is applied. It is interesting also to compare the growth and rate of acceptance of this particular research endeavor to the rates for other technological endeavors. Griibler [1997] cataloged the time required for introduction, diffusion,and acceptance of technological, economic, and social change and found mean values of 40 to 50 years. The introduction of the synchrotron source depends on both technical and non-technical factors, and the time scale at which this seems to be occurring is quite compatible with what is seen for other major innovations such as the railroad or the telegraph. It will be interesting to see how long the present rate of technological change and increase in scientific use can be maintained for the synchrotron x-ray source. A short summary of the present state of the synchrotron <span class="hlt">radiation-induced</span> x-ray emission (SRIXE) method is presented here. Basically, SRIXE experiments can include any that depend on the detection. of characteristic x-rays produced by the incident x-ray beam born the synchrotron source as they interact with a sample. Thus, experiments done to measure elemental composition, chemical state, crystal, structure, and other sample parameters can be considered in a discussion of SRIXE. It is also clear that the experimentalist may well wish to use a variety of complementary techniques for study of a given sample. For this reason, discussion of computed microtomography (CMT) and x-ray diffraction is included here. It is hoped that this present discussion will serve as a succinct introduction to the basic ideas of SRIXE for those not working in the field and possibly help to stimulate new types of work by those starting in the field as well as by experienced practitioners of the art. The topics covered include short descriptions of (1) the properties of synchrotron <span class="hlt">radiation</span>, (2) a description of facilities used for its production, (3) collimated microprobe, (4) focused microprobes, (5) continuum and monoenergetic excitation, (6) detection limits, (7) quantitation, (8) applications of SRIXE, (9) computed microtomography (CMT), and (10)chemical speciation using x-ray absorption near-edge structure (XANES) and extended x-ray absorption fine structure (EXAFS). An effort has been made to cite a wide variety of work from different laboratories to show the vital nature of the field.</p> <div class="credits"> <p class="dwt_author">Jones, Keith W.</p> <p class="dwt_publisher"></p> <p class="publishDate">1999-09-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">305</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1981RaPC...18..503K"> <span id="translatedtitle"><span class="hlt">Radiation-induced</span> grafting of acrylic acid onto polyethylene filaments</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary"><span class="hlt">Radiation-induced</span> grafting of acrylic acid onto high density polyethylene (PE) filaments was carried out in order to raise softening temperature and impart flame retardance and hydrophilic properties. Mutual ?-irradiation method was employed for the grafting in a mixture of acrylic acid (AA), ethylene dichloride and water containing a small amount of ferrous ammonium sulfate. The rate of grafting was very low at room temperature. On the other hand, large percent grafts were obtained when the grafting was performed at an elevated temperature. Activation energy for the initial rate of grafting was found to be 17 {kcal}/{mol} between 20 and 60°C and 10 {kcal}/{mol} between 60 and 80°C. Original PE filament begins to shrink at 70°C, show maximum shrinkage of 50% at 130°C and then breaks off at 136°C. When a 34% AA graft is converted to metallic salt such as sodium and calcium, the graft filament retains its filament form even above 300°C and gives maximum shrinkage of 15%. Burning tests by a wire-netting basket method indicate that graft filaments and its metallic salts do not form melting drops upon burning and are self-extinguishing. Original PE filament shows no moisture absorption, however, that of AA-grafted PE increases with increasing graft percent. The sodium salt of 15% graft shows the same level of moisture regain as cotton. The AA-grafted PE filament and its metallic salts can be dyed with cationic dyes even at 1% graft. Tensile properties of PE filament is impaired neither by grafting nor by conversion to metallic salts.</p> <div class="credits"> <p class="dwt_author">Kaji, K.; Okada, T.; Sakurada, I.</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">306</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/35550924"> <span id="translatedtitle">Oxidative stress and calpain inhibition <span class="hlt">induce</span> alpha B-<span class="hlt">crystallin</span> phosphorylation via p38MAPK and calcium signalling pathways in H9c2 cells</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">We investigated the response of ?B-<span class="hlt">crystallin</span> to oxidative stress and calpain inhibition in an attempt to elucidate the signalling pathways mediating its phosphorylation. Given the high expression levels of ?B-<span class="hlt">crystallin</span> in cardiac muscle one can evaluate the significance of its participation in preservation of homeostasis under adverse conditions. H9c2 cardiac myoblasts were used as our experimental model since their response</p> <div class="credits"> <p class="dwt_author">Ioanna-Katerina S. Aggeli; Isidoros Beis; Catherine Gaitanaki</p> <p class="dwt_publisher"></p> <p class="publishDate">2008-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">307</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2007APS..MARB22011R"> <span id="translatedtitle">Shock-<span class="hlt">induced</span> <span class="hlt">crystalline</span> instabilities</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Uniaxial deformations of single crystals such as those produced under planar shock loading can produce structural instabilities which compete with defect nucleation mechanisms. In fcc single crystals under (110) shock loading, the resulting body-centered orthorhombic crystal structure develops a long-wavelength dynamical instability associated with tetragonal shear distortions, which occurs at lower strains (pressures) than those predicted by the vanishing of the elastic constants at finite pressure (stiffness coefficients). The criterion for these instabilities is derived and verified by equilibrium and non-equilibrium molecular dynamics simulations [2]J. Wang, S. Yip, S.R. Phillpot, D. Wolf, Phys. Rev. Lett. 71, 4182 (1993)</p> <div class="credits"> <p class="dwt_author">Ravelo, Ramon; Holian, Brad Lee; Germann, Timothy C.</p> <p class="dwt_publisher"></p> <p class="publishDate">2007-03-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">308</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/22609778"> <span id="translatedtitle">Prevention of ?-<span class="hlt">radiation</span> <span class="hlt">induced</span> cellular genotoxicity by tempol: protection of hematopoietic system.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Tempol (TPL) under in vitro conditions reduced the extent of gamma <span class="hlt">radiation</span> <span class="hlt">induced</span> membrane lipid peroxidation and disappearance of covalently closed circular form of plasmid pBR322. TPL protected cellular DNA from <span class="hlt">radiation-induced</span> damage in various tissues under ex vivo and in vivo conditions as evidenced by comet assay. TPL also prevented <span class="hlt">radiation</span> <span class="hlt">induced</span> micronuclei formation (in peripheral blood leucocytes) and chromosomal aberrations (in bone marrow cells) in whole body irradiated mice. TPL enhanced the rate of repair of cellular DNA (blood leucocytes and bone marrow cells) damage when administered immediately after <span class="hlt">radiation</span> exposure as revealed from the increased Cellular DNA Repair Index (CRI). The studies thus provided compelling evidence to reveal the effectiveness of TPL to protect hematopoietic system from <span class="hlt">radiation</span> injury. PMID:22609778</p> <div class="credits"> <p class="dwt_author">Ramachandran, Lakshmy; Nair, Cherupally Krishnan Krishnan</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-09-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">309</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/31723722"> <span id="translatedtitle"><span class="hlt">Radiation-induced</span> rib fractures after hypofractionated stereotactic body <span class="hlt">radiation</span> therapy of non-small cell lung cancer: A dose– and volume–response analysis</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Background and purposeThe aim of this study is to analyse the dose–response and the volume–response of <span class="hlt">radiation-induced</span> rib fractures after hypofractionated stereotactic body <span class="hlt">radiation</span> therapy (SBRT).</p> <div class="credits"> <p class="dwt_author">Niclas Pettersson; Jan Nyman; Karl-Axel Johansson</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">310</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ppl.creol.ucf.edu/pub-228.pdf"> <span id="translatedtitle">Comparison of <span class="hlt">radiation-induced</span> transmission degradation of borosilicate crown optical glass from four different manufacturers</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/epsearch/">E-print Network</a></p> <p class="result-summary">Comparison of <span class="hlt">radiation-induced</span> transmission degradation of borosilicate crown optical glass from in optical glasses is often related with the presence of impurities, which are, intentionally or not, introduced during the manufacturing process. Glass manufacturers use proprietary fabrication processes</p> <div class="credits"> <p class="dwt_author">Glebov, Leon</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">311</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://dspace.mit.edu/handle/1721.1/67297"> <span id="translatedtitle">Irradiated Esophageal Cells are Protected from <span class="hlt">Radiation-Induced</span> Recombination by MnSOD Gene Therapy</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/epsearch/">E-print Network</a></p> <p class="result-summary"><span class="hlt">Radiation-induced</span> DNA damage is a precursor to mutagenesis and cytotoxicity. During radiotherapy, exposure of healthy tissues can lead to severe side effects. We explored the potential of mitochondrial SOD (MnSOD) gene ...</p> <div class="credits"> <p class="dwt_author">Niu, Yunyun</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">312</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ntis.gov/search/product.aspx?ABBR=DE2001766294"> <span id="translatedtitle">Effect of bulk composition on swelling and <span class="hlt">radiation-induced</span> segregation in austenitic alloys.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ntis.gov/search/index.aspx">National Technical Information Service (NTIS)</a></p> <p class="result-summary">Changes in bulk composition are known to affect both <span class="hlt">radiation-induced</span> segregation and microstructural development, including void swelling in austenitic stainless steels. In this work, three alloys have been studied: Fe-18Cr-8Ni alloy (bulk composition c...</p> <div class="credits"> <p class="dwt_author">T. R. Allen, J. I. Cole, N. L. Dietz, Y. Wang, G. S. Was, E. A. Kenik</p> <p class="dwt_publisher"></p> <p class="publishDate">2000-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">313</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20060034866&hterms=Radiation+physics&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DRadiation%2Bphysics"> <span id="translatedtitle">Obtaining Solutions to <span class="hlt">Radiation</span>-And Plasma <span class="hlt">Induced</span> FAilure Modes From Physics</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">A number of performance-limiting spacecraft problems will be qualitatively discussed: Spacecraft Charging, Deep Dielectric Charging, Solar Cell Arcing, Antenna Sparking, High Voltage Power Shorts, <span class="hlt">Radiation-induced</span> Defects in Semiconductors, and Degradation of Electronic Devices.</p> <div class="credits"> <p class="dwt_author">Frederickson, A.</p> <p class="dwt_publisher"></p> <p class="publishDate">1998-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">314</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2014PhRvB..89x5434Z"> <span id="translatedtitle">Tunable terahertz <span class="hlt">radiation</span> from graphene <span class="hlt">induced</span> by moving electrons</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Based on a structure consisting of a single graphene layer situated on periodic dielectric gratings, we show theoretically that terahertz <span class="hlt">radiation</span> can be generated by low-energy electron bunches moving atop the graphene layer. The THz emission arises from graphene plasmons excited efficiently by the moving electrons. We find that the <span class="hlt">radiation</span> intensity can be strongly enhanced due to the local field enhancement of graphene plasmons arising from their low losses and high confinement. Importantly, the <span class="hlt">radiation</span> frequency can be tuned over a wide spectral range by varying the Fermi level of the graphene layer. Our results could find applications in developing tunable and miniature free-electron terahertz <span class="hlt">radiation</span> sources.</p> <div class="credits"> <p class="dwt_author">Zhan, Tianrong; Han, Dezhuan; Hu, Xinhua; Liu, Xiaohan; Chui, Siu-Tat; Zi, Jian</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-06-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">315</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20040141559&hterms=genetic+transformation&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D40%26Ntt%3Dgenetic%2Btransformation"> <span id="translatedtitle">The potential influence of <span class="hlt">radiation-induced</span> microenvironments in neoplastic progression</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">Ionizing <span class="hlt">radiation</span> is a complete carcinogen, able both to initiate and promote neoplastic progression and is a known carcinogen of human and murine mammary gland. Tissue response to <span class="hlt">radiation</span> is a composite of genetic damage, cell death and induction of new gene expression patterns. Although DNA damage is believed to initiate carcinogenesis, the contribution of these other aspects of <span class="hlt">radiation</span> response are beginning to be explored. Our studies demonstrate that <span class="hlt">radiation</span> elicits rapid and persistent global alterations in the mammary gland microenvironment. We postulate that <span class="hlt">radiation-induced</span> microenvironments may affect epithelial cells neoplastic transformation by altering their number or susceptibility. Alternatively, <span class="hlt">radiation</span> <span class="hlt">induced</span> microenvironments may exert a selective force on initiated cells and/or be conducive to progression. A key impetus for these studies is the possibility that blocking these events could be a strategy to interrupt neoplastic progression.</p> <div class="credits"> <p class="dwt_author">Barcellos-Hoff, M. H.; Chatterjee, A. (Principal Investigator)</p> <p class="dwt_publisher"></p> <p class="publishDate">1998-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">316</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/44272052"> <span id="translatedtitle"><span class="hlt">Radiation-induced</span> absorption in high-purity silica fiber preforms</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">The effect of the preform fabrication procedure on the <span class="hlt">radiation-induced</span> absorption in KU-1 and KS-4V high-purity silica glasses was investigated (these glasses are used in fiber preform fabrication via outside fluorosilicate glass deposition on substrate rods and in the rod-in-tube process). The results demonstrate that the deposition of a reflective cladding onto KU-1 rods drastically increases the <span class="hlt">radiation-induced</span> UV absorption</p> <div class="credits"> <p class="dwt_author">M. O. Zabezhailov; A. L. Tomashuk; I. V. Nikolin; V. G. Plotnichenko</p> <p class="dwt_publisher"></p> <p class="publishDate">2005-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">317</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://cancerres.aacrjournals.org/cgi/reprint/54/2/468.pdf"> <span id="translatedtitle">Potentiation of <span class="hlt">Radiation-induced</span> Regrowth Delay in Murine Tumors by Fludarabine I</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Fludarabine (9-\\/3-n-arabinofuranosyl-2-fluoroadenine-5'-monophos- phate), an adenine nucleoside analogue, has previously been shown to inhibit the repair of <span class="hlt">radiation-induced</span> chromosome damage. Thus fludarabine may have therapeutic utility in combination with photon irradiation. The purpose of this study was to determine whether fludarabine could enhance <span class="hlt">radiation-induced</span> murine tumor regrowth de- lay and to determine the most effective dose and schedule of the combi-</p> <div class="credits"> <p class="dwt_author">Vincent Gr; Nancy Hunter; Luka Milas; William A. Brock; William Plunkett; Walter N. Hittelman</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">318</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/22004154"> <span id="translatedtitle"><span class="hlt">Radiation</span> <span class="hlt">induced</span> changes in electronic and dielectric properties of polyoxymethylene</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">First-principle calculations have been done for the Orthorhombic helical Polyoxymethylene. Electronic density of states calculation gives a value of 6.6 eV as the band gap. Phonon frequencies have been calculated at the Gamma point. Phonon modes show wave numbers ranging from 55 cm{sup -1} to 3020 cm{sup -1}. The value of Dielectric constant has been experimentally determined. The gamma irradiation of the sample causes variations in the electronic and dielectric properties of the material. Electrical conductivity increases with increase in dosage of irradiation. Percentage of <span class="hlt">crystallinity</span> increases where as the value of dielectric constant decreases with increase in dosage of irradiation.</p> <div class="credits"> <p class="dwt_author">Sreepad, H. R.; Ravi, H. R.; Ahmed, Khaleel; Waghmare, Umesh V. [Post-Graduate Department of Physics, Government College (Autonomous), Mandya-571401 (India); Theoretical Sciences Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore-560064 (India)</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-06-05</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">319</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/35730342"> <span id="translatedtitle">Aqueous humour and <span class="hlt">crystalline</span> lens changes associated with ultraviolet <span class="hlt">radiation</span> or mechanical damage to corneal epithelium in freshwater rainbow trout eyes</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">In vivo irradiation of the eye of the rainbow trout with moderately high doses of UV-B (0.75 to 1.5 J cm2) can produce corneal damage and persistent cataractous changes in the anterior part of the <span class="hlt">crystalline</span> lens within hours. Irradiation with UV-C (0.25 J cm2) also produces corneal damage but only temporary lens changes after 2–3 days. Cataractous changes can</p> <div class="credits"> <p class="dwt_author">M. J. Doughty; A. P. Cullen; C. A. Monteith-McMaster</p> <p class="dwt_publisher"></p> <p class="publishDate">1997-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">320</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.cumc.columbia.edu/dept/radoncology/raraf/journal/pone.0028559.pdf"> <span id="translatedtitle"><span class="hlt">Radiation-Induced</span> Carcinogenesis: Mechanistically Based Differences between Gamma-Rays and Neutrons, and</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/epsearch/">E-print Network</a></p> <p class="result-summary"><span class="hlt">Radiation-Induced</span> Carcinogenesis: Mechanistically Based Differences between Gamma-Rays and Neutrons: Mechanistically Based Differences between Gamma-Rays and Neutrons, and Interactions with DMBA. PLoS ONE 6(12): e dose/dose rate. Sparsely ionizing <span class="hlt">radiation</span> (e.g. c-rays) generally produces linear or upwardly curving</p> <div class="credits"> <p class="dwt_author">Brenner, David Jonathan</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_15");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' 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showDiv("page_18");' href="#" title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">321</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2009JTePh..54..894F"> <span id="translatedtitle">Spatial distribution of RF <span class="hlt">radiation</span> <span class="hlt">induced</span> by cascade shower in lunar regolith</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The results of calculation of the <span class="hlt">radiation</span> pattern of an electron-photon shower <span class="hlt">induced</span> by an ultrahigh-energy particle on the Moon’s surface are reported. It is found that the inclusion of dielectric characteristics of the lunar regolith radically changes the rf <span class="hlt">radiation</span> intensity distribution at the vacuum-regolith interface.</p> <div class="credits"> <p class="dwt_author">Filonenko, A. D.; Filonenko, V. A.</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-06-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">322</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/48575289"> <span id="translatedtitle">Moist Skin Care Can Diminish Acute<span class="hlt">Radiation-Induced</span> Skin Toxicity</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Background: <span class="hlt">Radiation</span> treatment may <span class="hlt">induce</span> acute skin reactions. There are several methods of managing them. Validity of these methods, however, is not sufficiently studied. We therefore investigated, whether moist skin care with 3% urea lotion will reduce acute <span class="hlt">radiation</span> skin toxicity. Patients and Methods: 88 patients with carcinomas of the head and neck undergoing radiotherapy with curative intent (mean total</p> <div class="credits"> <p class="dwt_author">Felix Momm; Christian Weißenberger; Susanne Bartelt; Michael Henke</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">323</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3741482"> <span id="translatedtitle">Curcumin Attenuates <span class="hlt">Radiation-Induced</span> Inflammation and Fibrosis in Rat Lungs</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">A beneficial radioprotective agent has been used to treat the <span class="hlt">radiation-induced</span> lung injury. This study was performed to investigate whether curcumin, which is known to have anti-inflammatory and antioxidant properties, could ameliorate <span class="hlt">radiation-induced</span> pulmonary inflammation and fibrosis in irradiated lungs. Rats were given daily doses of intragastric curcumin (200 mg/kg) prior to a single irradiation and for 8 weeks after <span class="hlt">radiation</span>. Histopathologic findings demonstrated that macrophage accumulation, interstitial edema, alveolar septal thickness, perivascular fibrosis, and collapse in <span class="hlt">radiation</span>-treated lungs were inhibited by curcumin administration. <span class="hlt">Radiation-induced</span> transforming growth factor-?1 (TGF-?1), connective tissue growth factor (CTGF) expression, and collagen accumulation were also inhibited by curcumin. Moreover, western blot analysis revealed that curcumin lowered <span class="hlt">radiation-induced</span> increases of tumor necrosis factor-? (TNF-?), TNF receptor 1 (TNFR1), and cyclooxygenase-2 (COX-2). Curcumin also inhibited the nuclear translocation of nuclear factor-? B (NF-?B) p65 in <span class="hlt">radiation</span>-treated lungs. These results indicate that long-term curcumin administration may reduce lung inflammation and fibrosis caused by <span class="hlt">radiation</span> treatment. PMID:23946685</p> <div class="credits"> <p class="dwt_author">Cho, Yu Ji; Yi, Chin Ok; Jeon, Byeong Tak; Jeong, Yi Yeong; Kang, Gi Mun; Lee, Jung Eun</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">324</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/20960219"> <span id="translatedtitle">Nanostructuring <span class="hlt">induced</span> enhancement of <span class="hlt">radiation</span> hardness in GaN epilayers</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">The <span class="hlt">radiation</span> hardness of as-grown and electrochemically nanostructured GaN epilayers against heavy ion irradiation was studied by means of photoluminescence (PL) and resonant Raman scattering (RRS) spectroscopy. A nanostructuring <span class="hlt">induced</span> enhancement of the GaN <span class="hlt">radiation</span> hardness by more than one order of magnitude was derived from the PL and RRS analyses. These findings show that electrochemical nanostructuring of GaN layers is a potentially attractive technology for the development of <span class="hlt">radiation</span> hard devices.</p> <div class="credits"> <p class="dwt_author">Ursaki, V. V.; Tiginyanu, I. M.; Volciuc, O.; Popa, V.; Skuratov, V. A.; Morkoc, H. [Laboratory of Low-Dimensional Semiconductor Structures, Institute of Applied Physics, Academy of Sciences of Moldova, Chisinau 2028 (Moldova, Republic of) and National Center for Materials Study and Testing, Technical University of Moldova, Chisinau 2004 (Moldova); Flerov Laboratory of Nuclear Reactions, Joint Institute for Nuclear Research, 141980 Dubna, Moscow region (Russian Federation); Department of Electrical and Computer Engineering, Virginia Commonwealth University, Richmond, Virginia 23284 and Department of Physics, Virginia Commonwealth University, Richmond, Virginia 23284 (United States)</p> <p class="dwt_publisher"></p> <p class="publishDate">2007-04-16</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">325</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/30253330"> <span id="translatedtitle"><span class="hlt">Radiation</span> <span class="hlt">induced</span> thyroid neoplasms 1920 to 1987: A vanishing problem</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary"><span class="hlt">Radiation</span> for benign diseases has been implicated as an etiologic factor in thyroid cancer. From 1930-60, over 2 million children may have been exposed to therapeutic <span class="hlt">radiation</span> and it is estimated that up to 7% may develop thyroid cancer after a 5-40 year latency. Thyroid stimulating hormone, secondary to radioinduced hypothyroidism, has been implicated as causative in animals. Such data</p> <div class="credits"> <p class="dwt_author">Minesh P. Mehta; Paul G. Goetowski; Timothy J. Kinsella</p> <p class="dwt_publisher"></p> <p class="publishDate">1989-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">326</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/servlets/purl/5622389"> <span id="translatedtitle">Early mechanisms in <span class="hlt">radiation-induced</span> biological damage</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">An introduction to the mechanisms of <span class="hlt">radiation</span> action in biological systems is presented. Several questions about the nature of the <span class="hlt">radiation</span> damage process are discussed, including recognition of the oxygen effects, dose-response relationships, and the importance of the hydroxyl radical. (ACR)</p> <div class="credits"> <p class="dwt_author">Powers, E.L.</p> <p class="dwt_publisher"></p> <p class="publishDate">1983-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">327</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2014cosp...40E3788Z"> <span id="translatedtitle">Epigenetic Analysis of Heavy-ion <span class="hlt">Radiation</span> <span class="hlt">Induced</span> Bystander Effects in Mice</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Abstract: <span class="hlt">Radiation-induced</span> bystander effect was defined as the induction of damage in neighboring non-hit cells by signals released from directly-irradiated cells. Recently, low dose of high LET <span class="hlt">radiation</span> <span class="hlt">induced</span> bystander effects in vivo have been reported more and more. It has been indicated that <span class="hlt">radiation</span> <span class="hlt">induced</span> bystander effect was localized not only in bystander tissues but also in distant organs. Genomic, epigenetic and proteomics plays significant roles in regulating heavy-ion <span class="hlt">radiation</span> stress responses in mice. To identify the molecular mechanism that underlies bystander effects of heavy-ion <span class="hlt">radiation</span>, the male Balb/c and C57BL mice were exposed head-only to 40, 200, 2000mGy dose of (12) C heavy-ion <span class="hlt">radiation</span>, while the rest of the animal body was shielded. Directly <span class="hlt">radiation</span> organ ear and the distant organ liver were detected on 1h, 6h, 12h and 24h after <span class="hlt">radiation</span>, respectively. Methylation-sensitive amplification polymorphism (MSAP) was used to monitor the level of polymorphic genomic DNA methylation changed with dose and time effects. The results show that heavy-ion irradiated mouse head could <span class="hlt">induce</span> genomic DNA methylation changes significantly in both the directly <span class="hlt">radiation</span> organ ear and the distant organ liver. The percent of DNA methylation changes were time-dependent and tissue-specific. Demethylation polymorphism rate was highest separately at 1 h in 200 mGy and 6 h in 2000 mGy after irradiation. The global DNA methylation changes tended to occur in the CG sites. The results illustrated that genomic methylation changes of heavy ion <span class="hlt">radiation-induced</span> bystander effect in liver could be obvious 1 h after <span class="hlt">radiation</span> and achieved the maximum at 6 h, while the changes could recover gradually at 12 h. The results suggest that mice head exposed to heavy-ion <span class="hlt">radiation</span> can <span class="hlt">induce</span> damage and methylation pattern changed in both directly <span class="hlt">radiation</span> organ ear and distant organ liver. Moreover, our findings are important to understand the molecular mechanism of <span class="hlt">radiation</span> <span class="hlt">induced</span> bystander effects in vivo.</p> <div class="credits"> <p class="dwt_author">Zhang, Meng; Sun, Yeqing; Cui, Changna; Xue, Bei</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">328</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4194292"> <span id="translatedtitle">Mechanisms of <span class="hlt">radiation-induced</span> normal tissue toxicity and implications for future clinical trials</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">To summarize current knowledge regarding mechanisms of <span class="hlt">radiation-induced</span> normal tissue injury and medical countermeasures available to reduce its severity. Advances in <span class="hlt">radiation</span> delivery using megavoltage and intensity-modulated <span class="hlt">radiation</span> therapy have permitted delivery of higher doses of <span class="hlt">radiation</span> to well-defined tumor target tissues. Injury to critical normal tissues and organs, however, poses substantial risks in the curative treatment of cancers, especially when <span class="hlt">radiation</span> is administered in combination with chemotherapy. The principal pathogenesis is initiated by depletion of tissue stem cells and progenitor cells and damage to vascular endothelial microvessels. Emerging concepts of <span class="hlt">radiation-induced</span> normal tissue toxicity suggest that the recovery and repopulation of stromal stem cells remain chronically impaired by long-lived free radicals, reactive oxygen species, and pro-inflammatory cytokines/chemokines resulting in progressive damage after <span class="hlt">radiation</span> exposure. Better understanding the mechanisms mediating interactions among excessive generation of reactive oxygen species, production of pro-inflammatory cytokines and activated macrophages, and role of bone marrow-derived progenitor and stem cells may provide novel insight on the pathogenesis of <span class="hlt">radiation-induced</span> injury of tissues. Further understanding the molecular signaling pathways of cytokines and chemokines would reveal novel targets for protecting or mitigating <span class="hlt">radiation</span> injury of tissues and organs.</p> <div class="credits"> <p class="dwt_author">Jenrow, Kenneth A.; Brown, Stephen L.</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">329</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2012PhDT.......117F"> <span id="translatedtitle"><span class="hlt">Radiation</span> <span class="hlt">Induced</span> Segregation in High Chromium Ferritic/Martensitic Steels</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">High Cr ferritic/martensitic (F/M) steels including nano-featured oxide dispersion strengthened steels (NF-ODS) are a candidate material class for advanced fission and fusion nuclear reactor designs. F/M steels have excellent high temperature strength, low swelling rates and the recent developments in NF-ODS steels has improved their high temperature creep performance. A concern for F/M steels is their <span class="hlt">radiation</span> <span class="hlt">induced</span> segregation (RIS) response while in-service. RIS occurs when atomic fluxes preferentially couple to point defect fluxes to defect sinks such as grain boundaries (GBs). For F/M steels no conclusive trends or dependencies on the RIS response have been drawn. Interfaces, including grain boundaries and precipitate-matrix interfaces can alter the RIS response. The grain boundary structure could change the point defect interaction at the GB. Changes in the point defect kinetics at a grain boundary could therefore alter the RIS response at the boundary. Furthermore, oxide nanoclusters in NF-ODS steel act as sinks for point defects under irradiation. The surface area and number density of these nanoclusters in NF-ODS steels could alter the point defect fluxes to GBs. Analytical microscopy techniques were conducted to determine the role of grain boundary structure and nanocluster dispersion on the RIS response in irradiated F/M steels. Here, a 9 wt. % Cr model alloy which simulates the structure of commercially available steels and 14YWT NF-ODS alloy was irradiated under numerous conditions. Both alloys were investigated using STEM/EDS and GB misorientation analysis. Experimental results indicate a preferential segregation of Cr to specific GB misorientations in the model F/M steel. Findings in the NF-ODS alloy indicates the stability of nanoclusters within the alloy alters the concentration gradient of the point defects near irradiated GBs. Based on these results, new theories on the role of interfaces in irradiated F/M steels was developed including a rate theory model which accounts for the GB misorientation angle within the RIS model. These theories will stimulate the development of new F/M steels which are highly resistant to RIS while in-service.</p> <div class="credits"> <p class="dwt_author">Field, Kevin G.</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">330</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20090014108&hterms=chromosomes&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dchromosomes"> <span id="translatedtitle">M-BAND Study of <span class="hlt">Radiation-Induced</span> Chromosome Aberrations in Human Epithelial Cells: <span class="hlt">Radiation</span> Quality and Dose Rate Effects</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">The advantage of the multicolor banding in situ hybridization (mBAND) technique is its ability to identify both inter- (translocation to unpainted chromosomes) and intra- (inversions and deletions within a single painted chromosome) chromosome aberrations simultaneously. To study the detailed rearrangement of low- and high-LET <span class="hlt">radiation</span> <span class="hlt">induced</span> chromosome aberrations in human epithelial cells (CH184B5F5/M10) in vitro, we performed a series of experiments with Cs-137 gamma rays of both low and high dose rates, neutrons of low dose rate and 600 MeV/u Fe ions of high dose rate, with chromosome 3 painted with multi-binding colors. We also compared the chromosome aberrations in both 2- and 3-dimensional cell cultures. Results of these experiments revealed the highest chromosome aberration frequencies after low dose rate neutron exposures. However, detailed analysis of the <span class="hlt">radiation</span> <span class="hlt">induced</span> inversions revealed that all three <span class="hlt">radiation</span> types <span class="hlt">induced</span> a low incidence of simple inversions. Most of the inversions in gamma-ray irradiated samples were accompanied by other types of intra-chromosomal aberrations but few inversions were accompanied by inter-chromosomal aberrations. In contrast, neutrons and Fe ions <span class="hlt">induced</span> a significant fraction of inversions that involved complex rearrangements of both inter- and intrachromosomal exchanges. The location of the breaks involved in chromosome exchanges was analyzed along the painted chromosome. The breakpoint distribution was found to be randomly localized on chromosome 3 after neutron or Fe ion exposure, whereas non-random distribution with clustering breakpoints was observed after -ray exposure. Our comparison of chromosome aberration yields between 2- and 3-dimensional cell cultures indicated a significant difference for gamma exposures, but not for Fe ion exposures. These experimental results indicated that the track structure of the <span class="hlt">radiation</span> and the cellular/chromosome structure can both affect <span class="hlt">radiation-induced</span> chromosome aberrations.</p> <div class="credits"> <p class="dwt_author">Hada, Megumi; Cucinotta, Francis; Wu, Honglu</p> <p class="dwt_publisher"></p> <p class="publishDate">2009-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">331</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20040087727&hterms=bystander+effect&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dbystander%2Beffect"> <span id="translatedtitle">Non-targeted and delayed effects of exposure to ionizing <span class="hlt">radiation</span>: I. <span class="hlt">Radiation-induced</span> genomic instability and bystander effects in vitro</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">A long-standing dogma in the <span class="hlt">radiation</span> sciences is that energy from <span class="hlt">radiation</span> must be deposited in the cell nucleus to elicit a biological effect. A number of non-targeted, delayed effects of ionizing <span class="hlt">radiation</span> have been described that challenge this dogma and pose new challenges to evaluating potential hazards associated with <span class="hlt">radiation</span> exposure. These effects include <span class="hlt">induced</span> genomic instability and non-targeted bystander effects. The in vitro evidence for non-targeted effects in <span class="hlt">radiation</span> biology will be reviewed, but the question as to how one extrapolates from these in vitro observations to the risk of <span class="hlt">radiation-induced</span> adverse health effects such as cancer remains open.</p> <div class="credits"> <p class="dwt_author">Morgan, William F.</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">332</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/12710868"> <span id="translatedtitle">Non-targeted and delayed effects of exposure to ionizing <span class="hlt">radiation</span>: I. <span class="hlt">Radiation-induced</span> genomic instability and bystander effects in vitro.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">A long-standing dogma in the <span class="hlt">radiation</span> sciences is that energy from <span class="hlt">radiation</span> must be deposited in the cell nucleus to elicit a biological effect. A number of non-targeted, delayed effects of ionizing <span class="hlt">radiation</span> have been described that challenge this dogma and pose new challenges to evaluating potential hazards associated with <span class="hlt">radiation</span> exposure. These effects include <span class="hlt">induced</span> genomic instability and non-targeted bystander effects. The in vitro evidence for non-targeted effects in <span class="hlt">radiation</span> biology will be reviewed, but the question as to how one extrapolates from these in vitro observations to the risk of <span class="hlt">radiation-induced</span> adverse health effects such as cancer remains open. PMID:12710868</p> <div class="credits"> <p class="dwt_author">Morgan, William F</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-05-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">333</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3901601"> <span id="translatedtitle">Low-Dose Bevacizumab Is Effective in <span class="hlt">Radiation-Induced</span> Necrosis</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Background <span class="hlt">Radiation-induced</span> necrosis is a complication of brain irradiation. Treatment options are limited. Methods The response to treatment with low-dose bevacizumab in 2 patients with <span class="hlt">radiation-induced</span> necrosis was reported. Results Both patients with metastatic melanoma, aged 48 and 51 years, had significant symptomatic and radiological improvement with low-dose bevacizumab treatment. Doses as low as 5 mg/kg every 6 weeks and 7.5 mg/kg i.v. every 4 weeks were used and were highly effective. Conclusions Low-dose bevacizumab is a solid option in the management of edema associated with <span class="hlt">radiation</span> necrosis. PMID:24474923</p> <div class="credits"> <p class="dwt_author">Alessandretti, Matheus; Buzaid, Antonio C.; Brandao, Raphael; Brandao, Erika P.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">334</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/12707163"> <span id="translatedtitle">Dynamic testing for <span class="hlt">radiation</span> <span class="hlt">induced</span> failures in a standard CMOS submicron technology pixel front-end</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">A testing method for the detection of performance degradation <span class="hlt">induced</span> by high-dose irradiation in high-energy experiments has been developed. This method was successfully applied for testing the analogue CMOS front-end of a silicon pixel detector. The major effects of <span class="hlt">radiation</span> <span class="hlt">induced</span> faults have been investigated with respect to the special layout used for the nMOS transistors</p> <div class="credits"> <p class="dwt_author">D. De Venuto; S. Corsi; M. J. Ohletz</p> <p class="dwt_publisher"></p> <p class="publishDate">1999-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">335</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/28104758"> <span id="translatedtitle">The genetics of <span class="hlt">radiation-induced</span> and sporadic osteosarcoma: a unifying theory?</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Cancer is a disease of the genome, with the neoplastic phenotype being passed from one cell generation to the other. <span class="hlt">Radiation-induced</span> cancer has often been considered to represent a unique entity amongst neoplasia, with the energy deposition being held responsible for both direct (gene mutations) and indirect (bystander effects, <span class="hlt">induced</span> instability etc) alterations to the cellular genome. However, radiogenic tumours</p> <div class="credits"> <p class="dwt_author">Michael Rosemann; Virginija Kuosaite; Michaela Nathrath; Michael J. Atkinson</p> <p class="dwt_publisher"></p> <p class="publishDate">2002-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">336</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.colorado.edu/MCDB/sulab/Wichmann%202006.pdf"> <span id="translatedtitle">Ionizing <span class="hlt">radiation</span> <span class="hlt">induces</span> caspase-dependent but Chk2-and p53-independent cell death</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/epsearch/">E-print Network</a></p> <p class="result-summary">on serine-20, disrupting the interaction of p53 with Mdm2 and leading to increased stability of p53 (12, 13 <span class="hlt">radiation</span> (IR) can <span class="hlt">induce</span> apoptosis via p53, which is the most commonly mutated gene in human cancers. Loss on these genes in Drosophila. In this article, we show that IR-<span class="hlt">induced</span> apoptosis still occurs in the imaginal</p> <div class="credits"> <p class="dwt_author">Su, Tin Tin</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">337</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/24727460"> <span id="translatedtitle">Mitigating the risk of <span class="hlt">radiation-induced</span> cancers: limitations and paradigms in drug development.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">The United States <span class="hlt">radiation</span> medical countermeasures (MCM) programme for radiological and nuclear incidents has been focusing on developing mitigators for the acute <span class="hlt">radiation</span> syndrome (ARS) and delayed effects of acute <span class="hlt">radiation</span> exposure (DEARE), and biodosimetry technologies to provide <span class="hlt">radiation</span> dose assessments for guiding treatment. Because a nuclear accident or terrorist incident could potentially expose a large number of people to low to moderate doses of ionising <span class="hlt">radiation</span>, and thus increase their excess lifetime cancer risk, there is an interest in developing mitigators for this purpose. This article discusses the current status, issues, and challenges regarding development of mitigators against <span class="hlt">radiation-induced</span> cancers. The challenges of developing mitigators for ARS include: the long latency between exposure and cancer manifestation, limitations of animal models, potential side effects of the mitigator itself, potential need for long-term use, the complexity of human trials to demonstrate effectiveness, and statistical power constraints for measuring health risks (and reduction of health risks after mitigation) following relatively low <span class="hlt">radiation</span> doses (<0.75 Gy). Nevertheless, progress in the understanding of the molecular mechanisms resulting in <span class="hlt">radiation</span> injury, along with parallel progress in dose assessment technologies, make this an opportune, if not critical, time to invest in research strategies that result in the development of agents to lower the risk of <span class="hlt">radiation-induced</span> cancers for populations that survive a significant <span class="hlt">radiation</span> exposure incident. PMID:24727460</p> <div class="credits"> <p class="dwt_author">Yoo, Stephen S; Jorgensen, Timothy J; Kennedy, Ann R; Boice, John D; Shapiro, Alla; Hu, Tom C-C; Moyer, Brian R; Grace, Marcy B; Kelloff, Gary J; Fenech, Michael; Prasanna, Pataje G S; Coleman, C Norman</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-06-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">338</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.risoe.dk/rispubl/reports_INIS/RISOR398.pdf"> <span id="translatedtitle"><span class="hlt">Radiation-Induced</span> Sprout and Growth Inhibition in</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/epsearch/">E-print Network</a></p> <p class="result-summary">HEALING HYDROLASES INHIBITION IONIZING <span class="hlt">RADIATION</span> EFFECTS LYASES MUSHROOMS ONIONS OXALIC ACID PATHOGENESIS (Aiiium cepa L. and others) . . . . 37 2 . 2 . 4 . Mushrooms (A-jJttcuJ t u j ' V t u i (Lange) Singer) 38</p> <div class="credits"> <p class="dwt_author"></p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">339</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/8134537"> <span id="translatedtitle">Failla Memorial Lecture. The prevalence of multilocus lesions in <span class="hlt">radiation-induced</span> mutants.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">In L5178Y mouse lymphoblasts, ionizing <span class="hlt">radiation-induced</span> mutant frequencies were dramatically higher when the genetic marker analyzed was heterozygous (tk+/tk-) than when hemizygous (tk+/tk0 or hprt+/hprt0). In contrast, base-change mutagens <span class="hlt">induced</span> similar mutant frequencies at heterozygous and hemizygous loci. These results indicate that the majority of <span class="hlt">radiation-induced</span> mutants harbor multilocus lesions, and that these mutants are poorly recovered when the target gene is in a hemizygous chromosomal region. Dose-rate dependence of <span class="hlt">radiation-induced</span> mutant frequency was demonstrated at the heterozygous tk locus but not at the hemizygous hprt locus; in a cell line deficient in the rejoining of DNA double-strand breaks (DSBs), no dose-rate dependence was observed for either locus. The majority of TK-/- mutants, whether spontaneous or <span class="hlt">induced</span> by X, alpha-particle or UV <span class="hlt">radiation</span>, or by photosensitization, showed loss of the entire active tk allele. The percentage of TK-/- mutants exhibiting inactivation of galactokinase, encoded by the neighboring gk gene, was high in UV repair-deficient cells exposed to UV <span class="hlt">radiation</span> and in DNA DSB repair-deficient lines exposed to X <span class="hlt">radiation</span>. Thus the presence of unrepaired DNA lesions, whether DSBs or pyrimidine dimers, appears to result in an increase in the percentage of mutants harboring multilocus lesions. PMID:8134537</p> <div class="credits"> <p class="dwt_author">Evans, H H</p> <p class="dwt_publisher"></p> <p class="publishDate">1994-02-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">340</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20010038423&hterms=DTm&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DDTm"> <span id="translatedtitle">Numerical Investigation of <span class="hlt">Radiative</span> Heat Transfer in Laser <span class="hlt">Induced</span> Air Plasmas</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary"><span class="hlt">Radiative</span> heat transfer is one of the most important phenomena in the laser <span class="hlt">induced</span> plasmas. This study is intended to develop accurate and efficient methods for predicting laser <span class="hlt">radiation</span> absorption and plasma <span class="hlt">radiative</span> heat transfer, and investigate the plasma <span class="hlt">radiation</span> effects in laser propelled vehicles. To model laser <span class="hlt">radiation</span> absorption, a ray tracing method along with the Beer's law is adopted. To solve the <span class="hlt">radiative</span> transfer equation in the air plasmas, the discrete transfer method (DTM) is selected and explained. The air plasma <span class="hlt">radiative</span> properties are predicted by the LORAN code. To validate the present nonequilibrium <span class="hlt">radiation</span> model, several benchmark problems are examined and the present results are found to match the available solutions. To investigate the effects of plasma <span class="hlt">radiation</span> in laser propelled vehicles, the present <span class="hlt">radiation</span> code is coupled into a plasma aerodynamics code and a selected problem is considered. Comparisons of results at different cases show that plasma <span class="hlt">radiation</span> plays a role of cooling plasma and it lowers the plasma temperature by about 10%. This change in temperature also results in a reduction of the coupling coefficient by about 10-20%. The present study indicates that plasma <span class="hlt">radiation</span> modeling is very important for accurate modeling of aerodynamics in a laser propelled vehicle.</p> <div class="credits"> <p class="dwt_author">Liu, J.; Chen, Y. S.; Wang, T. S.; Turner, James E. (Technical Monitor)</p> <p class="dwt_publisher"></p> <p class="publishDate">2001-01-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_16");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a onClick='return showDiv("page_3");' href="#">3</a> <a onClick='return 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href="#">11</a> <a onClick='return showDiv("page_12");' href="#">12</a> <a onClick='return showDiv("page_13");' href="#">13</a> <a onClick='return showDiv("page_14");' href="#">14</a> <a onClick='return showDiv("page_15");' href="#">15</a> <a onClick='return showDiv("page_16");' href="#">16</a> <a onClick='return showDiv("page_17");' href="#">17</a> <a style="font-weight: bold;">18</a> <a onClick='return showDiv("page_19");' href="#">19</a> <a onClick='return showDiv("page_20");' href="#">20</a> <a onClick='return showDiv("page_21");' href="#">21</a> <a onClick='return showDiv("page_22");' href="#">22</a> <a onClick='return showDiv("page_23");' href="#">23</a> <a onClick='return showDiv("page_24");' href="#">24</a> <a onClick='return showDiv("page_25");' href="#">25</a> </span> </span> <a id="NextPageLink" onclick='return showDiv("page_19");' href="#" title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">341</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/22439436"> <span id="translatedtitle">Amelioration of ionizing <span class="hlt">radiation</span> <span class="hlt">induced</span> lipid peroxidation in mouse liver by Moringa oleifera Lam. leaf extract.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Protective effect of Moringa oleifera leaf extract (MoLE) against <span class="hlt">radiation-induced</span> lipid peroxidation has been investigated. Swiss albino mice, selected from an inbred colony, were administered with MoLE (300 mg/kg body wt) for 15 days before exposing to a single dose of 5 Gy 60Co-gamma <span class="hlt">radiation</span>. After treatments, animals were necropsied at different post irradiation intervals (days 1, 7 and 15) and hepatic lipid peroxidation and reduced glutathione (GSH) contents were estimated to observe the relative changes due to irradiation and its possible amelioration by MoLE. It was observed that, MoLE treatment restored GSH in liver and prevented <span class="hlt">radiation</span> <span class="hlt">induced</span> augmentation in hepatic lipid peroxidation. Phytochemical analysis showed that MoLE possess various phytochemicals such as ascorbic acid, phenolics (catechin, epicatechin, ferulic acid, ellagic acid, myricetin) etc., which may play the key role in prevention of hepatic lipid peroxidation by scavenging <span class="hlt">radiation</span> <span class="hlt">induced</span> free radicals. PMID:22439436</p> <div class="credits"> <p class="dwt_author">Sinha, Mahuya; Das, Dipesh Kr; Datta, Sanjukta; Ghosh, Santinath; Dey, Sanjit</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-03-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">342</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1993SPIE.1795..296B"> <span id="translatedtitle">Compensation of fading effects of <span class="hlt">radiation-induced</span> loss by multiple wavelengths measurements</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The <span class="hlt">radiation</span> <span class="hlt">induced</span> loss of multimode lead glass fibers is measured during and after irradiation by a Co-60 source in the temperature range from 10 degree(s)C to 50 degree(s)C. The measurements were performed at visible and infrared LED wavelengths using time multiplexing of the LED's. The <span class="hlt">radiation</span> sensitivity and relaxation effects of this fiber depend on temperature and on the wavelength of the read-out light. The wavelength dependence allows estimation of the actual fiber temperature. Thus a method can be developed to compensate temperature and fading effects on <span class="hlt">radiation</span> <span class="hlt">induced</span> loss in situations where the fiber temperature is unknown. The application of multiple wavelength measurements of <span class="hlt">induced</span> loss for <span class="hlt">radiation</span> dosimetry with optical fibers is discussed.</p> <div class="credits"> <p class="dwt_author">Bueker, Harald; Haesing, Friedrich W.; Gerhard, E.</p> <p class="dwt_publisher"></p> <p class="publishDate">1993-03-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">343</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/30381701"> <span id="translatedtitle">Clinical and dosimetric predictors of <span class="hlt">radiation-induced</span> esophageal toxicity</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Purpose: To evaluate the incidence, severity, and clinical\\/dosimetric predictors of acute and chronic esophageal toxicities in patients with non-small cell lung cancer (NSCLC) treated with high-dose conformal thoracic <span class="hlt">radiation</span>.Methods and Materials: Ninety-one patients with localized NSCLC treated definitively with high-dose conformal <span class="hlt">radiation</span> therapy (RT) at Duke University Medical Center (DUMC) were reviewed. Patient characteristics were as follows: 53 males and</p> <div class="credits"> <p class="dwt_author">Patrick D Maguire; Gregory S Sibley; Su-Min Zhou; Timothy A Jamieson; Kim L Light; Phillip A Antoine; James E Herndon; Mitchell S Anscher; Lawrence B Marks</p> <p class="dwt_publisher"></p> <p class="publishDate">1999-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">344</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/18507547"> <span id="translatedtitle">YAG laser-<span class="hlt">induced</span> ?-BaB 2O 4 <span class="hlt">crystalline</span> dot formation in Sm 2O 3–BaO–B 2O 3 glasses</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">A continuous-wave (CW) YAG laser (power: 0.75–0.9J\\/s, irradiation time: 15s–15min) with a wavelength of 1064nm is irradiated to 11.1Sm2O3·44.4BaO·44.4B2O3 glass, and the formation of ?-BaB2O4 (?-BBO) <span class="hlt">crystalline</span> dots with a diameter of 30–150?m is confirmed from micro-Raman spectra. ?-BBO crystals with around 200?m length grow towards the interior of the glass. The incorporation of Sm3+ into ?-BBO <span class="hlt">crystalline</span> dots is</p> <div class="credits"> <p class="dwt_author">H Tanaka; T Honma; Y Benino; T Fujiwara; T Komatsu</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">345</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20040087650&hterms=DNA&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DDNA"> <span id="translatedtitle">Clustered DNA damages <span class="hlt">induced</span> in human hematopoietic cells by low doses of ionizing <span class="hlt">radiation</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">Ionizing <span class="hlt">radiation</span> <span class="hlt">induces</span> clusters of DNA damages--oxidized bases, abasic sites and strand breaks--on opposing strands within a few helical turns. Such damages have been postulated to be difficult to repair, as are double strand breaks (one type of cluster). We have shown that low doses of low and high linear energy transfer (LET) <span class="hlt">radiation</span> <span class="hlt">induce</span> such damage clusters in human cells. In human cells, DSB are about 30% of the total of complex damages, and the levels of DSBs and oxidized pyrimidine clusters are similar. The dose responses for cluster induction in cells can be described by a linear relationship, implying that even low doses of ionizing <span class="hlt">radiation</span> can produce clustered damages. Studies are in progress to determine whether clusters can be produced by mechanisms other than ionizing <span class="hlt">radiation</span>, as well as the levels of various cluster types formed by low and high LET <span class="hlt">radiation</span>.</p> <div class="credits"> <p class="dwt_author">Sutherland, Betsy M.; Bennett, Paula V.; Cintron-Torres, Nela; Hada, Megumi; Trunk, John; Monteleone, Denise; Sutherland, John C.; Laval, Jacques; Stanislaus, Marisha; Gewirtz, Alan</p> <p class="dwt_publisher"></p> <p class="publishDate">2002-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">346</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/22218239"> <span id="translatedtitle">Surface photoconductivity of organosilicate glass dielectrics <span class="hlt">induced</span> by vacuum-ultraviolet <span class="hlt">radiation</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">The temporary increase in the electrical surface conductivity of low-k organosilicate glass (SiCOH) during exposure to vacuum-ultraviolet <span class="hlt">radiation</span> (VUV) is investigated. To measure the photoconductivity, patterned “comb structures” are deposited on dielectric films and exposed to synchrotron <span class="hlt">radiation</span> in the range of 8–25 eV, which is in the energy range of most plasma vacuum-ultraviolet <span class="hlt">radiation</span>. The change in photo surface conductivity <span class="hlt">induced</span> by VUV <span class="hlt">radiation</span> may be beneficial in limiting charging damage of dielectrics by depleting the plasma-deposited charge.</p> <div class="credits"> <p class="dwt_author">Zheng, H.; Nichols, M. T.; Pei, D.; Shohet, J. L. [Plasma Processing and Technology Laboratory and Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)] [Plasma Processing and Technology Laboratory and Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); Nishi, Y. [Department of Electrical Engineering, Stanford University, Stanford, CA 94305 (United States)] [Department of Electrical Engineering, Stanford University, Stanford, CA 94305 (United States)</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-08-14</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">347</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/1991asee.nasa..181P"> <span id="translatedtitle">Naturally <span class="hlt">induced</span> secondary <span class="hlt">radiation</span> in interplanetary space: Preliminary analyses for gamma <span class="hlt">radiation</span> and radioisotope production from thermal neutron activation</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Thermal neutron activation analyses were carried out for various space systems components to determine gamma <span class="hlt">radiation</span> dose rates and food <span class="hlt">radiation</span> contamination levels. The space systems components selected were those for which previous <span class="hlt">radiation</span> studies existed. These include manned space vehicle <span class="hlt">radiation</span> shielding, liquid hydrogen propellant tanks for a Mars mission, and a food supply used as space vehicle <span class="hlt">radiation</span> shielding. The computational method used is based on the fast neutron distribution generated by the BRYNTRN and HZETRN transport codes for Galactic Cosmic Rays (GCR) at solar minimum conditions and intense solar flares in space systems components. The gamma dose rates for soft tissue are calculated for water and aluminum space vehicle slab shields considering volumetric source self-attenuation and exponential buildup factors. In the case of the lunar habitat with regolith shielding, a completely exposed spherical habitat was assumed for mathematical convenience and conservative calculations. Activation analysis of the food supply used as <span class="hlt">radiation</span> shielding is presented for four selected nutrients: potassium, calcium, sodium, and phosphorus. Radioactive isotopes that could represent a health hazard if ingested are identified and their concentrations are identified. For nutrients soluble in water, it was found that all <span class="hlt">induced</span> radioactivity was below the accepted maximum permissible concentrations.</p> <div class="credits"> <p class="dwt_author">Plaza-Rosado, Heriberto</p> <p class="dwt_publisher"></p> <p class="publishDate">1991-09-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">348</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19920004637&hterms=neutron+activation+analysis&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dneutron%2Bactivation%2Banalysis"> <span id="translatedtitle">Naturally <span class="hlt">induced</span> secondary <span class="hlt">radiation</span> in interplanetary space: Preliminary analyses for gamma <span class="hlt">radiation</span> and radioisotope production from thermal neutron activation</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">Thermal neutron activation analyses were carried out for various space systems components to determine gamma <span class="hlt">radiation</span> dose rates and food <span class="hlt">radiation</span> contamination levels. The space systems components selected were those for which previous <span class="hlt">radiation</span> studies existed. These include manned space vehicle <span class="hlt">radiation</span> shielding, liquid hydrogen propellant tanks for a Mars mission, and a food supply used as space vehicle <span class="hlt">radiation</span> shielding. The computational method used is based on the fast neutron distribution generated by the BRYNTRN and HZETRN transport codes for Galactic Cosmic Rays (GCR) at solar minimum conditions and intense solar flares in space systems components. The gamma dose rates for soft tissue are calculated for water and aluminum space vehicle slab shields considering volumetric source self-attenuation and exponential buildup factors. In the case of the lunar habitat with regolith shielding, a completely exposed spherical habitat was assumed for mathematical convenience and conservative calculations. Activation analysis of the food supply used as <span class="hlt">radiation</span> shielding is presented for four selected nutrients: potassium, calcium, sodium, and phosphorus. Radioactive isotopes that could represent a health hazard if ingested are identified and their concentrations are identified. For nutrients soluble in water, it was found that all <span class="hlt">induced</span> radioactivity was below the accepted maximum permissible concentrations.</p> <div class="credits"> <p class="dwt_author">Plaza-Rosado, Heriberto</p> <p class="dwt_publisher"></p> <p class="publishDate">1991-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">349</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20130013689&hterms=chromosomes&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dchromosomes"> <span id="translatedtitle">Chromatin Folding, Fragile Sites, and Chromosome Aberrations <span class="hlt">Induced</span> by Low- and High- LET <span class="hlt">Radiation</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">We previously demonstrated non-random distributions of breaks involved in chromosome aberrations <span class="hlt">induced</span> by low- and high-LET <span class="hlt">radiation</span>. To investigate the factors contributing to the break point distribution in <span class="hlt">radiation-induced</span> chromosome aberrations, human epithelial cells were fixed in G1 phase. Interphase chromosomes were hybridized with a multicolor banding in situ hybridization (mBAND) probe for chromosome 3 which distinguishes six regions of the chromosome in separate colors. After the images were captured with a laser scanning confocal microscope, the 3-dimensional structure of interphase chromosome 3 was reconstructed at multimega base pair scale. Specific locations of the chromosome, in interphase, were also analyzed with bacterial artificial chromosome (BAC) probes. Both mBAND and BAC studies revealed non-random folding of chromatin in interphase, and suggested association of interphase chromatin folding to the <span class="hlt">radiation-induced</span> chromosome aberration hotspots. We further investigated the distribution of genes, as well as the distribution of breaks found in tumor cells. Comparisons of these distributions to the <span class="hlt">radiation</span> hotspots showed that some of the <span class="hlt">radiation</span> hotspots coincide with the frequent breaks found in solid tumors and with the fragile sites for other environmental toxins. Our results suggest that multiple factors, including the chromatin structure and the gene distribution, can contribute to <span class="hlt">radiation-induced</span> chromosome aberrations.</p> <div class="credits"> <p class="dwt_author">Zhang, Ye; Cox, Bradley; Asaithamby, Aroumougame; Chen, David J.; Wu, Honglu</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">350</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/22149591"> <span id="translatedtitle">A Prospective Cohort Study on <span class="hlt">Radiation-induced</span> Hypothyroidism: Development of an NTCP Model</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">Purpose: To establish a multivariate normal tissue complication probability (NTCP) model for <span class="hlt">radiation-induced</span> hypothyroidism. Methods and Materials: The thyroid-stimulating hormone (TSH) level of 105 patients treated with (chemo-) <span class="hlt">radiation</span> therapy for head-and-neck cancer was prospectively measured during a median follow-up of 2.5 years. Hypothyroidism was defined as elevated serum TSH with decreased or normal free thyroxin (T4). A multivariate logistic regression model with bootstrapping was used to determine the most important prognostic variables for <span class="hlt">radiation-induced</span> hypothyroidism. Results: Thirty-five patients (33%) developed primary hypothyroidism within 2 years after <span class="hlt">radiation</span> therapy. An NTCP model based on 2 variables, including the mean thyroid gland dose and the thyroid gland volume, was most predictive for <span class="hlt">radiation-induced</span> hypothyroidism. NTCP values increased with higher mean thyroid gland dose (odds ratio [OR]: 1.064/Gy) and decreased with higher thyroid gland volume (OR: 0.826/cm{sup 3}). Model performance was good with an area under the curve (AUC) of 0.85. Conclusions: This is the first prospective study resulting in an NTCP model for <span class="hlt">radiation-induced</span> hypothyroidism. The probability of hypothyroidism rises with increasing dose to the thyroid gland, whereas it reduces with increasing thyroid gland volume.</p> <div class="credits"> <p class="dwt_author">Boomsma, Marjolein J.; Bijl, Hendrik P.; Christianen, Miranda E.M.C.; Beetz, Ivo; Chouvalova, Olga; Steenbakkers, Roel J.H.M. [Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen (Netherlands); Laan, Bernard F.A.M. van der [Department of Otorhinolaryngology/Head and Neck Surgery, University Medical Center Groningen, University of Groningen, Groningen (Netherlands); Wolffenbuttel, Bruce H.R. [Department of Endocrinology, University Medical Center Groningen, University of Groningen, Groningen (Netherlands)] [Department of Endocrinology, University Medical Center Groningen, University of Groningen, Groningen (Netherlands); Oosting, Sjoukje F. [Department of Medical Oncology, University Medical Center Groningen, University of Groningen, Groningen (Netherlands)] [Department of Medical Oncology, University Medical Center Groningen, University of Groningen, Groningen (Netherlands); Schilstra, Cornelis [Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen (Netherlands)] [Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen (Netherlands); Langendijk, Johannes A., E-mail: j.a.langendijk@umcg.nl [Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen (Netherlands)</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-11-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">351</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/25135631"> <span id="translatedtitle">Sodium tanshinone IIA sulfonate attenuates <span class="hlt">radiation-induced</span> fibrosis damage in cardiac fibroblasts.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">The main pathological change in <span class="hlt">radiation-induced</span> heart disease is fibrosis. Emerging evidence has indicated that sodium tanshinone IIA sulfonate (STS) was used for treating ?brosis diseases. The present study was undertaken to characterize the effect of STS on <span class="hlt">radiation-induced</span> cardiac fibrosis (RICF) on cultured cardiac fibroblasts (CFs). CFs were irradiated with 1 or 2 Gy X-rays, and the expression of TGF-?1 and collagen I (Col-1) increased, indicating that low-dose X-rays promoted fibrosis damage effect. The fibrosis damage was accompanied by morphologic changes in the endoplasmic reticulum (ER), as well as an increase in the expression of the ER stress-related molecules, GRP78 and CHOP. Administration of STS reduced ROS production and decreased the expression of Col-1, TGF-?1, p-Smad2/3, GRP78, and CHOP in irradiated CFs, thus weakening the <span class="hlt">radiation-induced</span> fibrosis damage and ER stress. <span class="hlt">Radiation-induced</span> fibrosis damage was observed on a cellular level. The involvement of ER stress in <span class="hlt">radiation-induced</span> fibrosis damage was demonstrated for the first time. STS attenuated the fibrosis damage effect in CFs and this effect may be related to its antioxidant action, and also related to its inhibition of ER stress and TGF-?1-Smad pathway. These results suggest that STS shows a good prospect in clinical prevention and treatment of RICF. PMID:25135631</p> <div class="credits"> <p class="dwt_author">Gu, Jing; Li, Hai-Long; Wu, Hong-Yan; Gu, Mei; Li, Ying-Dong; Wang, Xiao-Gang; Ming, Hai-Xia; Dong, Xiao-Li; Liu, Kai</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">352</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/18648589"> <span id="translatedtitle">Will <span class="hlt">radiation-induced</span> bystander effects or adaptive responses impact on the shape of the dose response relationships at low doses of ionizing <span class="hlt">radiation</span>?</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary"><span class="hlt">Radiation</span> <span class="hlt">induced</span> bystander effects and adaptive responses are two phenomena that modulate cellular responses to low doses of ionizing <span class="hlt">radiation</span>. Bystander effects generally exaggerate the effects of low doses of <span class="hlt">radiation</span> by eliciting detrimental effects in nonirradiated cells, thus making the target for <span class="hlt">radiation</span> effects greater than the volume irradiated. Adaptive responses on the other hand indicate that low doses of <span class="hlt">radiation</span> can reduce damage <span class="hlt">induced</span> by a second challenging dose. The potential impact of these two low dose effects on the shape of the dose response relationship will be discussed. PMID:18648589</p> <div class="credits"> <p class="dwt_author">Morgan, William F</p> <p class="dwt_publisher"></p> <p class="publishDate">2006-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">353</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013M%26PSA..76.5239V"> <span id="translatedtitle">Optical Bleaching Effect and <span class="hlt">Induced</span> <span class="hlt">Radiation</span> Response in Chelyabinsk Meteorite</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The features of optically stimulated luminescence have been studied in Chelyabinsk LL5 chondrite after X-ray irradiation. The decay parameters of <span class="hlt">induced</span> lightsum decrease have been evaluated for observed bleaching processes.</p> <div class="credits"> <p class="dwt_author">Vokhmintsev, A. S.; Weinstein, I. A.; Grokhovsky, V. I.</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-09-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">354</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/18519566"> <span id="translatedtitle">Cosmic ray <span class="hlt">radiation</span> effects caused by proton-<span class="hlt">induced</span> fragmentation</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">In space, <span class="hlt">radiation</span> effects in which a large amount of energy is transferred by a single particle are observed. These effects can be caused by either the direct ionization of a cosmic ray heavy ion or alternatively by the ionization of short range target fragments which are produced inside the material by interactions of cosmic ray particles. Protons of the</p> <div class="credits"> <p class="dwt_author">W. Heinrich; T. Streibel; M. Ahrendt; H. Röcher; G. Hüntrup</p> <p class="dwt_publisher"></p> <p class="publishDate">1997-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">355</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/60593021"> <span id="translatedtitle">Synchrotron-<span class="hlt">Radiation</span> <span class="hlt">Induced</span> X-Ray Emission (SRIXE)</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Elemental analysis using emission of characteristic x rays is a well-established scientific method. The success of this analytical method is highly dependent on the properties of the source used to produce the x rays. X-ray tubes have long existed as a principal excitation source, but electron and proton beams have also been employed extensively. The development of the synchrotron <span class="hlt">radiation</span></p> <div class="credits"> <p class="dwt_author">Keith W</p> <p class="dwt_publisher"></p> <p class="publishDate">1999-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">356</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/60564002"> <span id="translatedtitle"><span class="hlt">Radiation</span> <span class="hlt">Induced</span> Stress Relaxation in Silicone and Polyurethane Elastomers</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Many different materials are used in the National Ignition Facility, NIF, located at Lawrence Livermore National Laboratory, LLNL. Some of these are exposed to significant doses of ionizing <span class="hlt">radiation</span>. Two elastomers are of special interest because they are used in sealing applications with long expected lifetimes. These are LPU4, a polyurethane formulated at LLNL, and Dow Corning DC93-500, a silicone</p> <div class="credits"> <p class="dwt_author">G Spellman; W Gourdin; W Jensen; M Pearson; I Fine</p> <p class="dwt_publisher"></p> <p class="publishDate">2007-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">357</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/10857377"> <span id="translatedtitle">[Repair of ionizing <span class="hlt">radiation</span> <span class="hlt">induced</span> DNA double strand breaks].</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">DNA double-strand breaks (DSB) are created by ionizing <span class="hlt">radiation</span>, an important environmental genotoxic agent. DSB are repaired by two mechanisms associated with recombination. In eukaryotic cells homologous recombination depends on genes belonging to the RAD52 epistatic group. Alternative pathway, DNA end-joining in non-homologous recombination involves DNA-dependent protein kinase (DNA-PK). PMID:10857377</p> <div class="credits"> <p class="dwt_author">Wid?ak, P</p> <p class="dwt_publisher"></p> <p class="publishDate">2000-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">358</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20060031419&hterms=springer&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dspringer"> <span id="translatedtitle">Assessing application vulnerability to <span class="hlt">radiation-induced</span> SEUs in memory</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">One of the goals of the Remote Exploration and Experimentation (REE) project at JPL is to determine how vulnerable applications are to single event upsets (SEUs) when run in low <span class="hlt">radiation</span> space environments using commercial-off-the-shelf (COTS) components.</p> <div class="credits"> <p class="dwt_author">Springer, P. L.</p> <p class="dwt_publisher"></p> <p class="publishDate">2001-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">359</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/51490563"> <span id="translatedtitle">Bubble translation and deformation <span class="hlt">induced</span> by ultrasound <span class="hlt">radiation</span> force</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Measurement of small-bubble dynamics has been proposed for the remote evaluation of tissue elasticity [Erpelding et al., Proc. IEEE Ultrasonics Symp., 554-557, 2003]. For example, a microbubble can be produced within the cornea during femtosecond laser surgery and its response to a pulsed ultrasonic <span class="hlt">radiation</span> force can be measured. The bubble's translation, deformation, and oscillation can be directly related to</p> <div class="credits"> <p class="dwt_author">Yurii A. Ilinskii; G. Douglas Meegan; Evgenia A. Zabolotskaya; Stanislav Y. Emelianov</p> <p class="dwt_publisher"></p> <p class="publishDate">2001-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">360</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/34239669"> <span id="translatedtitle"><span class="hlt">Radiation-induced</span> malignant and atypical peripheral nerve sheath tumors</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">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 <span class="hlt">radiation</span> treatment on peripheral nerve. In all instances the radio-theray</p> <div class="credits"> <p class="dwt_author">Kathleen M. Foley; James M. Woodruff; Frank T. Ellis; Jerome B. Posner</p> <p class="dwt_publisher"></p> <p class="publishDate">1980-01-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_17");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a onClick='return showDiv("page_3");' href="#">3</a> <a onClick='return showDiv("page_4");' 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showDiv("page_12");' href="#">12</a> <a onClick='return showDiv("page_13");' href="#">13</a> <a onClick='return showDiv("page_14");' href="#">14</a> <a onClick='return showDiv("page_15");' href="#">15</a> <a onClick='return showDiv("page_16");' href="#">16</a> <a onClick='return showDiv("page_17");' href="#">17</a> <a onClick='return showDiv("page_18");' href="#">18</a> <a style="font-weight: bold;">19</a> <a onClick='return showDiv("page_20");' href="#">20</a> <a onClick='return showDiv("page_21");' href="#">21</a> <a onClick='return showDiv("page_22");' href="#">22</a> <a onClick='return showDiv("page_23");' href="#">23</a> <a onClick='return showDiv("page_24");' href="#">24</a> <a onClick='return showDiv("page_25");' href="#">25</a> </span> </span> <a id="NextPageLink" onclick='return showDiv("page_20");' href="#" title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">361</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19730024107&hterms=Solid-state+Physics&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D80%26Ntt%3D%2522Solid-state%2BPhysics%2522"> <span id="translatedtitle">Study of interaction among silicon, lithium, oxygen and <span class="hlt">radiation-induced</span> defects for <span class="hlt">radiation</span>-hardened solar cells</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">In order to improve reliability and the useful lifetime of solar cell arrays for space use, a program was undertaken to develop <span class="hlt">radiation</span>-hardened lithium-doped silicon solar cells. These cells were shown to be significantly more resistant to degradation by ionized particles than the presently used n-p nonlithium-doped silicon solar cells. The results of various analyses performed to develop a more complete understanding of the physics of the interaction among lithium, silicon, oxygen, and <span class="hlt">radiation-induced</span> defects are presented. A discussion is given of those portions of the previous model of <span class="hlt">radiation</span> damage annealing which were found to be in error and those portions which were upheld by these extensive investigations.</p> <div class="credits"> <p class="dwt_author">Berman, P. A.</p> <p class="dwt_publisher"></p> <p class="publishDate">1973-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">362</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4222525"> <span id="translatedtitle"><span class="hlt">Radiation-Induced</span> Apoptosis Varies Among Individuals and is Modified by Sex and Age</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Purpose Although there are considerable data on mechanisms of <span class="hlt">radiation-induced</span> apoptosis in vitro and in animal models, little is known about functional variation in these pathways in humans. We sought to develop a tractable system to evaluate this. Materials and methods Peripheral blood mononuclear cells were isolated from 90 healthy volunteers, divided into two aliquots, one irradiated with a 5 Gy dose and the other sham-treated (0 Gy), and assessed for damage-<span class="hlt">induced</span> apoptosis after 24 hours. To investigate reproducibility, ten individuals spanning the entire <span class="hlt">radiation-induced</span> apoptotic range were tested three times each, with 3–6 months between replicates. Results We observed surprising heterogeneity in apoptosis among individuals, ranging from 21–62%. Biological replicates from a single individual, however, were completely concordant, suggesting the variability observed across individuals is not the result of stochastic or short-term effects. We found significantly higher <span class="hlt">radiation-induced</span> apoptosis in males than in females (Mean: 41.0% vs. 30.7%; p < 3.5 × 10?7). Moreover, advancing age was associated with decreasing <span class="hlt">radiation-induced</span> apoptosis in males (p = 0.01) but not females (p = 0.82).a Conclusions Our results provide evidence that the function of cellular pathways crucial for stress-<span class="hlt">induced</span> apoptosis varies by sex and could decline with age in humans. PMID:24882388</p> <div class="credits"> <p class="dwt_author">Applebaum, Mark A.; Skol, Andrew D.; Bond, Elisabeth E.; Overholtzer, Michael; Bond, Gareth L.; Onel, Kenan</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">363</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/22559204"> <span id="translatedtitle">Spatially fractionated <span class="hlt">radiation</span> <span class="hlt">induces</span> cytotoxicity and changes in gene expression in bystander and <span class="hlt">radiation</span> adjacent murine carcinoma cells.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary"><span class="hlt">Radiation-induced</span> bystander effects have been extensively studied at low doses, since evidence of bystander <span class="hlt">induced</span> cell killing and other effects on unirradiated cells were found to be predominant at doses up to 0.5 Gy. Therefore, few studies have examined bystander effects <span class="hlt">induced</span> by exposure to higher doses of <span class="hlt">radiation</span>, such as spatially fractionated <span class="hlt">radiation</span> (GRID) treatment. In the present study, we evaluate the ability of GRID treatment to <span class="hlt">induce</span> changes in GRID adjacent (bystander) regions, in two different murine carcinoma cell lines following exposure to a single irradiation dose of 10 Gy. Murine SCK mammary carcinoma cells and SCCVII squamous carcinoma cells were irradiated using a brass collimator to create a GRID pattern of nine circular fields 12 mm in diameter with a center-to-center distance of 18 mm. Similar to the typical clinical implementation of GRID, this is approximately a 50:50 ratio of direct and bystander exposure. We also performed experiments by irradiating separate cultures and transferring the medium to unirradiated bystander cultures. Clonogenic survival was evaluated in both cell lines to determine the occurrence of <span class="hlt">radiation-induced</span> bystander effects. For the purpose of our study, we have defined bystander cells as GRID adjacent cells that received approximately 1 Gy scatter dose or unirradiated cells receiving conditioned medium from irradiated cells. We observed significant bystander killing of cells adjacent to the GRID irradiated regions compared to sham treated controls. We also observed bystander killing of SCK and SCCVII cells cultured in conditioned medium obtained from cells irradiated with 10 Gy. Therefore, our results confirm the occurrence of bystander effects following exposure to a high-dose of <span class="hlt">radiation</span> and suggest that cell-to-cell contact is not required for these effects. In addition, the gene expression profile for DNA damage and cellular stress response signaling in SCCVII cells after GRID exposure was studied. The occurrence of GRID-<span class="hlt">induced</span> bystander gene expression changes in significant numbers of DNA damage and cellular stress response signaling genes, providing molecular evidence for possible mechanisms of bystander cell killing. PMID:22559204</p> <div class="credits"> <p class="dwt_author">Asur, Rajalakshmi S; Sharma, Sunil; Chang, Ching-Wei; Penagaricano, Jose; Kommuru, Indira M; Moros, Eduardo G; Corry, Peter M; Griffin, Robert J</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-06-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">364</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3870688"> <span id="translatedtitle">Lnk adaptor suppresses <span class="hlt">radiation</span> resistance and <span class="hlt">radiation-induced</span> B-cell malignancies by inhibiting IL-11 signaling</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">The Lnk (Sh2b3) adaptor protein dampens the response of hematopoietic stem cells and progenitors (HSPCs) to a variety of cytokines by inhibiting JAK2 signaling. As a consequence, Lnk?/? mice develop hematopoietic hyperplasia, which progresses to a phenotype resembling the nonacute phase of myeloproliferative neoplasm. In addition, Lnk mutations have been identified in human myeloproliferative neoplasms and acute leukemia. We find that Lnk suppresses the development of <span class="hlt">radiation-induced</span> acute B-cell malignancies in mice. Lnk-deficient HSPCs recover more effectively from irradiation than their wild-type counterparts, and this resistance of Lnk?/? HSPCs to <span class="hlt">radiation</span> underlies the subsequent emergence of leukemia. A search for the mechanism responsible for <span class="hlt">radiation</span> resistance identified the cytokine IL-11 as being critical for the ability of Lnk?/? HSPCs to recover from irradiation and subsequently become leukemic. In IL-11 signaling, wild-type Lnk suppresses tyrosine phosphorylation of the Src homology region 2 domain-containing phosphatase-2/protein tyrosine phosphatase nonreceptor type 11 and its association with the growth factor receptor-bound protein 2, as well as activation of the Erk MAP kinase pathway. Indeed, Src homology region 2 domain-containing phosphatase-2 has a binding motif for the Lnk Src Homology 2 domain that is phosphorylated in response to IL-11 stimulation. IL-11 therefore drives a pathway that enhances HSPC radioresistance and <span class="hlt">radiation-induced</span> B-cell malignancies, but is normally attenuated by the inhibitory adaptor Lnk. PMID:24297922</p> <div class="credits"> <p class="dwt_author">Louria-Hayon, Igal; Frelin, Catherine; Ruston, Julie; Gish, Gerald; Jin, Jing; Kofler, Michael M.; Lambert, Jean-Philippe; Adissu, Hibret A.; Milyavsky, Michael; Herrington, Robert; Minden, Mark D.; Dick, John E.; Gingras, Anne-Claude; Iscove, Norman N.; Pawson, Tony</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">365</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/24136023"> <span id="translatedtitle"><span class="hlt">Radiation-induced</span> gliomas in 2 pediatric patients with neurofibromatosis type 1: case study and summary of the literature.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Neurofibromatosis type 1 (NF1) is a genetic disorder that predisposes patients to the formation of sporadic tumors and also increases the risk of <span class="hlt">radiation-induced</span> malignancies. The most commonly described <span class="hlt">radiation-induced</span> tumor in NF1 patients is a malignant peripheral nerve sheath tumor. We present 2 children with NF1 who received <span class="hlt">radiation</span> therapy and subsequently developed high-grade gliomas. We then review the current literature on <span class="hlt">radiation-induced</span> tumors in NF1 patients. Although <span class="hlt">radiation</span> may be the most appropriate therapy in specific situations for children with NF1, the secondary tumor risk should be carefully considered. PMID:24136023</p> <div class="credits"> <p class="dwt_author">Madden, Jennifer R; Rush, Sarah Z; Stence, Nicholas; Foreman, Nicholas K; Liu, Arthur K</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-03-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">366</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/20020650"> <span id="translatedtitle">A stochastic model of <span class="hlt">radiation-induced</span> bone marrow damage</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">A stochastic model, based on consensus principles from <span class="hlt">radiation</span> biology, is used to estimate bone-marrow stem cell pool survival (CFU-S and stroma cells) after irradiation. The dose response model consists of three coupled first order linear differential equations which quantitatively describe time dependent cellular damage, repair, and killing of red bone marrow cells. This system of differential equations is solved analytically through the use of a matrix approach for continuous and fractionated irradiations. The analytic solutions are confirmed through the dynamical solution of the model equations using SIMULINK. Rate coefficients describing the cellular processes of <span class="hlt">radiation</span> damage and repair, extrapolated to humans from animal data sets and adjusted for neutron-gamma mixed fields, are employed in a SIMULINK analysis of criticality accidents. The results show that, for the time structures which may occur in criticality accidents, cell survival is established mainly by the average dose and dose rate.</p> <div class="credits"> <p class="dwt_author">Cotlet, G.; Blue, T.E.</p> <p class="dwt_publisher"></p> <p class="publishDate">2000-03-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">367</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/25360944"> <span id="translatedtitle">Dispersive <span class="hlt">radiation</span> <span class="hlt">induced</span> by shock waves in passive resonators.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">We show that passive Kerr resonators pumped close to zero dispersion wavelengths on the normal dispersion side can develop the resonant generation of linear waves driven by cavity (mixed dispersive-dissipative) shock waves. The resonance mechanism can be successfully described in the framework of the generalized Lugiato-Lefever equation with higher-order dispersive terms. Substantial differences with <span class="hlt">radiation</span> from cavity solitons and purely dispersive shock waves dispersion are highlighted. PMID:25360944</p> <div class="credits"> <p class="dwt_author">Malaguti, Stefania; Conforti, Matteo; Trillo, Stefano</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-10-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">368</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.cancer.gov/clinicaltrials/featured/trials/MAYO-MCS285"> <span id="translatedtitle">Electroacupuncture for <span class="hlt">Radiation-Induced</span> Chronic Dry Mouth</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.cancer.gov">Cancer.gov</a></p> <p class="result-summary">In this clinical trial, head and neck cancer patients with chronic dry mouth who completed <span class="hlt">radiation</span> therapy at least 6 months before joining the trial and who received no benefit from treatment with the drug pilocarpine (Salagen) will be randomly assigned to undergo electroacupuncture using a machine called a LISS stimulator, or a sham procedure, using a similar-looking machine that does not produce electrical stimulation.</p> <div class="credits"> <p class="dwt_author"></p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">369</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/30486692"> <span id="translatedtitle">Dosimetric and clinical predictors for <span class="hlt">radiation-induced</span> esophageal injury</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Purpose: To evaluate the clinical and three-dimensional dosimetric parameters associated with esophageal injury after radiotherapy (RT) for non-small-cell lung cancer. Methods and materials: The records of 254 patients treated for non-small-cell lung cancer between 1992 and 2001 were reviewed. A variety of metrics describing the esophageal dose were extracted. The <span class="hlt">Radiation</span> Therapy Oncology Group toxicity criteria for grading of esophageal</p> <div class="credits"> <p class="dwt_author">Sung-Ja Ahn; Daniel Kahn; Sumin Zhou; Xiaoli Yu; Donna M. S. Hollis; Timothy D. Shafman; Lawrence B.. Marks</p> <p class="dwt_publisher"></p> <p class="publishDate">2005-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">370</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ajnr.org/cgi/reprint/17/10/1932.pdf"> <span id="translatedtitle"><span class="hlt">Radiation-Induced</span> Brachial Plexopathy: MR and Clinical Findings</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Summary: A 54-year-old man had a slowly progressive bilateral brachial plexopathy 17 months after surgery and <span class="hlt">radiation</span> ther- apy for a stage IV supraglottic carcinoma. MR imaging at pre- sentation showed a symmetric pattern of parascalene and inter- scalene hyperintense signal on T2-weighted images and after contrast enhancement. Although hyperintense signal has been more often associated with recurrent tumor than</p> <div class="credits"> <p class="dwt_author">Brian C. Bowen; Ashok Verma; Alfred H. Brandon; Jeffery A. Fiedler</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">371</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/24840434"> <span id="translatedtitle">Effect of MPG on <span class="hlt">radiation-induced</span> odontogenic tissue metaplasia</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">This investigation monitored the effect of 2-mercaptopropionylglycine (MPG) in reducing <span class="hlt">radiation</span> damage to the tooth-forming tissues. Fifty rats were exposed to x-ray doses of between 3 and 19 Gy directed toward the maxillary incisor germinal centers. Half of the animals were given an injection of MPG before irradiation, while the other rats were injected with saline solution. Administration of MPG</p> <div class="credits"> <p class="dwt_author">J. R. Geist; A. H. Kafrawy; R. E. Shupe</p> <p class="dwt_publisher"></p> <p class="publishDate">1988-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">372</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2004PhRvD..70b4014M"> <span id="translatedtitle">Chern-Simons-like action <span class="hlt">induced</span> <span class="hlt">radiatively</span> in general relativity</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The Chern-Simons-like gravitational action is evaluated explicitly in four-dimensional space-time by <span class="hlt">radiative</span> corrections at the one-loop level. The calculation is performed in the fermionic sector where the Dirac fermions interact with the background gravitational field, including the parity-violating term ?¯b/?5?. The investigation takes into account the weak field approximation and dimensional regularization scheme.</p> <div class="credits"> <p class="dwt_author">Mariz, T.; Nascimento, J. R.; Passos, E.; Ribeiro, R. F.</p> <p class="dwt_publisher"></p> <p class="publishDate">2004-07-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">373</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3991713"> <span id="translatedtitle">C/EBP? Deficiency Sensitizes Mice to Ionizing <span class="hlt">Radiation-Induced</span> Hematopoietic and Intestinal Injury</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Knowledge of the mechanisms involved in the <span class="hlt">radiation</span> response is critical for developing interventions to mitigate <span class="hlt">radiation-induced</span> injury to normal tissues. Exposure to <span class="hlt">radiation</span> leads to increased oxidative stress, DNA-damage, genomic instability and inflammation. The transcription factor CCAAT/enhancer binding protein delta (Cebpd; C/EBP? is implicated in regulation of these same processes, but its role in <span class="hlt">radiation</span> response is not known. We investigated the role of C/EBP? in <span class="hlt">radiation-induced</span> hematopoietic and intestinal injury using a Cebpd knockout mouse model. Cebpd?/? mice showed increased lethality at 7.4 and 8.5 Gy total-body irradiation (TBI), compared to Cebpd+/+ mice. Two weeks after a 6 Gy dose of TBI, Cebpd?/? mice showed decreased recovery of white blood cells, neutrophils, platelets, myeloid cells and bone marrow mononuclear cells, decreased colony-forming ability of bone marrow progenitor cells, and increased apoptosis of hematopoietic progenitor and stem cells compared to Cebpd+/+ controls. Cebpd?/? mice exhibited a significant dose-dependent decrease in intestinal crypt survival and in plasma citrulline levels compared to Cebpd+/+ mice after exposure to <span class="hlt">radiation</span>. This was accompanied by significantly decreased expression of ?-H2AX in Cebpd?/? intestinal crypts and villi at 1 h post-TBI, increased mitotic index at 24 h post-TBI, and increase in apoptosis in intestinal crypts and stromal cells of Cebpd?/? compared to Cebpd+/+ mice at 4 h post-irradiation. This study uncovers a novel biological function for C/EBP? in promoting the response to <span class="hlt">radiation-induced</span> DNA-damage and in protecting hematopoietic and intestinal tissues from <span class="hlt">radiation-induced</span> injury. PMID:24747529</p> <div class="credits"> <p class="dwt_author">Chang, Jianhui; Wang, Wenze; Pathak, Rupak; Zhu, Xiaoyan; Wang, Junru; Hendrickson, Howard; Boerma, Marjan; Sterneck, Esta; Zhou, Daohong; Hauer-Jensen, Martin</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">374</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=19730011000&hterms=media+influence+children&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3D%2528%2528media%2Binfluence%2529%2Bchildren%2529"> <span id="translatedtitle">Energy Distribution of Electrons in <span class="hlt">Radiation</span> <span class="hlt">Induced</span>-Helium Plasmas. Ph.D. Thesis</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">Energy distribution of high energy electrons as they slow down and thermalize in a gaseous medium is studied. The energy distribution in the entire energy range from source energies down is studied analytically. A helium medium in which primary electrons are created by the passage of heavy-charged particles from nuclear reactions is emphasized. A <span class="hlt">radiation-induced</span> plasma is of interest in a variety of applications, such as <span class="hlt">radiation</span> pumped lasers and gaseous core nuclear reactors.</p> <div class="credits"> <p class="dwt_author">Lo, R. H.</p> <p class="dwt_publisher"></p> <p class="publishDate">1972-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">375</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/34761812"> <span id="translatedtitle">Biologically-based risk estimation for <span class="hlt">radiation-induced</span> chronic myeloid leukemia</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary"><span class="hlt">Radiation</span> cancer risks are typically determined by the use of simple statistical descriptions of epidemiological data. It\\u000a is important in risk assessment in general, however, to attempt to incorporate as much biological information into the risk\\u000a models as possible. We illustrate this by presenting a biologically-based linear-quadratic-exponential (LQE) incidence rate\\u000a model for <span class="hlt">radiation-induced</span> chronic myeloid leukemia (CML). The model consists</p> <div class="credits"> <p class="dwt_author">Tomas Radivoyevitch; David G. Hoel</p> <p class="dwt_publisher"></p> <p class="publishDate">2000-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">376</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/26400454"> <span id="translatedtitle"><span class="hlt">Radiation</span> damage of a barium fluoride scintillator <span class="hlt">induced</span> with 1 GeV proton irradiation</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary"><span class="hlt">Radiation</span> damage effects both in the optical transmission and in the fast luminescence component light output due to 1 GeV proton irradiation in a BaF2 crystal scintillator were measured. It was found that the <span class="hlt">induced</span> light absorption in a BaF2 crystal due to the proton <span class="hlt">radiation</span> damage is remarkably dependent on the dose accumulation rate. Also, the obtained results show</p> <div class="credits"> <p class="dwt_author">D. M. Seliverstov; A. I. Shchetkovsky; V. V. Yanovsky</p> <p class="dwt_publisher"></p> <p class="publishDate">1993-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">377</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2014RaPC...94..115K"> <span id="translatedtitle">Functionalization of polymer surfaces by <span class="hlt">radiation-induced</span> grafting for separation of heavy metal ions</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The reported investigations were focused on the elucidation of the most important factors influencing <span class="hlt">radiation-induced</span> grafting, particularly on studying the relationship between layer structure formed via copolymerization and content of monomers in the initial solution. Sorption capacity of the prepared by <span class="hlt">radiation</span> grafting adsorber was evaluated by gamma radiometer using 152Eu3+ as a marker monitoring depletion of the radioisotope from the feed solution.</p> <div class="credits"> <p class="dwt_author">Kornacka, E. M.; Przybytniak, G.; Fuks, L.; Walo, M.; ?yczko, K.</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">378</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1013116"> <span id="translatedtitle">The significance of <span class="hlt">radiation-induced</span> chromosome abnormalities in radiological protection</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">A brief review is given of the production and analysis of chromosome aberrations <span class="hlt">induced</span> by ionizing <span class="hlt">radiation</span>. The various tissues in which it is possible to demonstrate aberrations are noted and particular emphasis is laid on the culture of peripheral blood lymphocytes. Some examples of recent applications of the technique are described. These are in the determination of suspected overdoses to <span class="hlt">radiation</span> workers, in estimating doses to radiotherapy patients, and investigating the depth/biological profile for a negative ? meson beam. PMID:4841086</p> <div class="credits"> <p class="dwt_author">Dolphin, G. W.; Lloyd, D. C.</p> <p class="dwt_publisher"></p> <p class="publishDate">1974-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">379</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/30445818"> <span id="translatedtitle"><span class="hlt">Radiation-induced</span> second cancers: the impact of 3D-CRT and IMRT</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Information concerning <span class="hlt">radiation-induced</span> malignancies comes from the A-bomb survivors and from medically exposed individuals, including second cancers in <span class="hlt">radiation</span> therapy patients. The A-bomb survivors show an excess incidence of carcinomas in tissues such as the gastrointestinal tract, breast, thyroid, and bladder, which is linear with dose up to about 2.5 Sv. There is great uncertainty concerning the dose–response relationship for</p> <div class="credits"> <p class="dwt_author">Eric J Hall; Cheng-Shie Wuu</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">380</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2003AdSpR..31..119S"> <span id="translatedtitle">Cognitive deficits <span class="hlt">induced</span> by 56Fe <span class="hlt">radiation</span> exposure</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Exposing rats to particles of high energy and charge (e.g., 56Fe) disrupts neuronal systems and the behaviors mediated by them; these adverse behavioral and neuronal effects are similar to those seen in aged animals. Because cognition declines with age, and our previous study showed that <span class="hlt">radiation</span> disrupted Morris water maze spatial learning and memory performance, the present study used an 8-arm radial maze (RAM) to further test the cognitive behavioral consequences of <span class="hlt">radiation</span> exposure. Control rats or rats exposed to whole-body irradiation with 1.0 Gy of 1 GeV/n high-energy 56Fe particles (delivered at the alternating gradient synchrotron at Brookhaven National Laboratory) were tested nine months following exposure. <span class="hlt">Radiation</span> adversely affected RAM performance, and the changes seen parallel those of aging. Irradiated animals entered baited arms during the first 4 choices significantly less than did controls, produced their first error sooner, and also tended to make more errors as measured by re-entries into non-baited arms. These results show that irradiation with high-energy particles produces age-like decrements in cognitive behavior that may impair the ability of astronauts to perform critical tasks during long-term space travel beyond the magnetosphere.</p> <div class="credits"> <p class="dwt_author">Shukitt-Hale, B.; Casadesus, G.; Cantuti-Castelvetri, I.; Rabin, B. M.; Joseph, J. A.</p> <p class="dwt_publisher"></p> <p class="publishDate"></p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_18");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a onClick='return showDiv("page_3");' href="#">3</a> <a onClick='return showDiv("page_4");' href="#">4</a> <a 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src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_19");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a onClick='return showDiv("page_3");' href="#">3</a> <a onClick='return showDiv("page_4");' href="#">4</a> <a onClick='return showDiv("page_5");' href="#">5</a> <a onClick='return showDiv("page_6");' href="#">6</a> <a onClick='return showDiv("page_7");' href="#">7</a> <a onClick='return showDiv("page_8");' href="#">8</a> <a onClick='return showDiv("page_9");' href="#">9</a> <a onClick='return showDiv("page_10");' href="#">10</a> <a onClick='return showDiv("page_11");' href="#">11</a> <a onClick='return showDiv("page_12");' href="#">12</a> <a onClick='return showDiv("page_13");' href="#">13</a> <a onClick='return showDiv("page_14");' href="#">14</a> <a onClick='return showDiv("page_15");' href="#">15</a> <a onClick='return showDiv("page_16");' href="#">16</a> <a onClick='return showDiv("page_17");' href="#">17</a> <a onClick='return showDiv("page_18");' href="#">18</a> <a onClick='return showDiv("page_19");' href="#">19</a> <a style="font-weight: bold;">20</a> <a onClick='return showDiv("page_21");' href="#">21</a> <a onClick='return showDiv("page_22");' href="#">22</a> <a onClick='return showDiv("page_23");' href="#">23</a> <a onClick='return showDiv("page_24");' href="#">24</a> <a onClick='return showDiv("page_25");' href="#">25</a> </span> </span> <a id="NextPageLink" onclick='return showDiv("page_21");' href="#" title="Next Page"> <img id="NextPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.next.18x20.png" alt="Next Page" /></a> <a id="LastPageLink" onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">381</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013PhRvD..87h3511B"> <span id="translatedtitle">Lee-Wick <span class="hlt">radiation</span> <span class="hlt">induced</span> bouncing universe models</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The present article discusses the effect of a Lee-Wick partner infested <span class="hlt">radiation</span> phase of the early universe. As Lee-Wick partners can contribute negative energy density it is always possible that at some early phase of the universe when the Lee-Wick partners were thermalized the total energy density of the universe became very small making the effective Hubble radius very big. This possibility gives rise to the probability of a bouncing universe. As will be shown in the article a simple Lee-Wick <span class="hlt">radiation</span> is not enough to produce a bounce. There can be two possibilities which can produce a bounce in the Lee-Wick <span class="hlt">radiation</span> phase. One requires a cold dark matter candidate to trigger the bounce and the other possibility requires the bouncing temperature to be fine-tuned such as all the Lee-Wick partners of the standard fields are not thermalized at the bounce temperature. Both the possibilities give rise to a blue-tilted power spectrum of metric perturbations. Moreover the bouncing universe model can predict the lower limit of the masses of the Lee-Wick partners of chiral fermions and massless gauge bosons. The mass limit intrinsically depends upon the bounce temperature.</p> <div class="credits"> <p class="dwt_author">Bhattacharya, Kaushik; Cai, Yi-Fu; Das, Suratna</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-04-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">382</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20040087860&hterms=elsevier&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3Delsevier"> <span id="translatedtitle">Cognitive deficits <span class="hlt">induced</span> by 56Fe <span class="hlt">radiation</span> exposure</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">Exposing rats to particles of high energy and charge (e.g., 56Fe) disrupts neuronal systems and the behaviors mediated by them; these adverse behavioral and neuronal effects are similar to those seen in aged animals. Because cognition declines with age, and our previous study showed that <span class="hlt">radiation</span> disrupted Morris water maze spatial learning and memory performance, the present study used an 8-arm radial maze (RAM) to further test the cognitive behavioral consequences of <span class="hlt">radiation</span> exposure. Control rats or rats exposed to whole-body irradiation with 1.0 Gy of 1 GeV/n high-energy 56Fe particles (delivered at the alternating gradient synchrotron at Brookhaven National Laboratory) were tested nine months following exposure. <span class="hlt">Radiation</span> adversely affected RAM performance, and the changes seen parallel those of aging. Irradiated animals entered baited arms during the first 4 choices significantly less than did controls, produced their first error sooner, and also tended to make more errors as measured by re-entries into non-baited arms. These results show that irradiation with high-energy particles produces age-like decrements in cognitive behavior that may impair the ability of astronauts to perform critical tasks during long-term space travel beyond the magnetosphere. Published by Elsevier Science Ltd on behalf of COSPAR.</p> <div class="credits"> <p class="dwt_author">Shukitt-Hale, B.; Casadesus, G.; Cantuti-Castelvetri, I.; Rabin, B. M.; Joseph, J. A.</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">383</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/6605110"> <span id="translatedtitle"><span class="hlt">Radiation-induced</span> proctitis cystica profunda in the rat</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">Therapeutic pelvic irradiation is notorious for the production of clinically significant sequela after a long latency. One of the rarest of these complications is proctitis cystica profunda (PCP). To study the histologic changes of chronic <span class="hlt">radiation</span> proctitis, we evaluated 35 female Wistar rats that had received a single exposure of 22.5 Gy of <span class="hlt">radiation</span> to the rectum and were then followed for one year. We identified PCP and its precursor lesions in 18 rats. The fully developed lesion consisted of a focal expansion of the submucosa by dilated cystic spaces lined by a single layer of benign epithelial cells. Usually, PCP evolved as glands herniated between small defects in the muscularis mucosae. Mitotic figures were not recognized in the cells lining the herniating glands. In two rats, the <span class="hlt">radiation</span> had apparently caused large ulcers, which had subsequently reepithelialized, resulting in prominent submucosal glandular tissue. Although the number of goblet cells in the displaced epithelium was reduced, the cells had rather mature appearances ultrastructurally. Glands displaced into the submucosa were encased by an intact basal lamina but lacked in muscularis.</p> <div class="credits"> <p class="dwt_author">Geisinger, K.R.; Scobey, M.W.; Northway, M.G.; Cassidy, K.T.; Castell, D.O. (Wake Forest Univ., Winston-Salem, NC (USA))</p> <p class="dwt_publisher"></p> <p class="publishDate">1990-07-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">384</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/22395787"> <span id="translatedtitle">Cellular neoplastic transformation <span class="hlt">induced</span> by 916 MHz microwave <span class="hlt">radiation</span>.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">There has been growing concern about the possibility of adverse health effects resulting from exposure to microwave <span class="hlt">radiations</span>, such as those emitted by mobile phones. The purpose of this study was to investigate the cellular neoplastic transformation effects of electromagnetic fields. 916 MHz continuous microwave was employed in our study to simulate the electromagnetic <span class="hlt">radiation</span> of mobile phone. NIH/3T3 cells were adopted in our experiment due to their sensitivity to carcinogen or cancer promoter in environment. They were divided randomly into one control group and three microwave groups. The three microwave groups were exposed to 916 MHz EMF for 2 h per day with power density of 10, 50, and 90 w/m(2), respectively, in which 10 w/m(2) was close to intensity near the antenna of mobile phone. The morphology and proliferation of NIH/3T3 cells were examined and furthermore soft agar culture and animal carcinogenesis assay were carried out to determine the neoplastic promotion. Our experiments showed NIH/3T3 cells changed in morphology and proliferation after 5-8 weeks exposure and formed clone in soft agar culture after another 3-4 weeks depending on the exposure intensity. In the animal carcinogenesis study, lumps developed on the back of SCID mice after being inoculated into exposed NIH/3T3 cells for more than 4 weeks. The results indicate that microwave <span class="hlt">radiation</span> can promote neoplastic transformation of NIH/3T3cells. PMID:22395787</p> <div class="credits"> <p class="dwt_author">Yang, Lei; Hao, Dongmei; Wang, Minglian; Zeng, Yi; Wu, Shuicai; Zeng, Yanjun</p> <p class="dwt_publisher"></p> <p class="publishDate">2012-08-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">385</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4226825"> <span id="translatedtitle">Regorafenib-<span class="hlt">induced</span> transverse myelopathy after stereotactic body <span class="hlt">radiation</span> therapy</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Stereotactic body <span class="hlt">radiation</span> therapy (SBRT) delivers large doses of <span class="hlt">radiation</span> with great accuracy, but is known to have deleterious effects on the vascular compartment of irradiated tissues. Combining SBRT with targeted anti-angiogenesis agents, while able to increase therapeutic efficacy, may unexpectedly precipitate vascular-based toxicities. In this report, we describe a patient with colon cancer who developed transverse myelopathy from regorafenib 2 years after receiving SBRT for three metastatic liver lesions. Regorafenib (Stivarga), formerly BAY 73-4506, (Bayer HealthCare Pharmaceuticals, Montville, NJ) is a multiple receptor tyrosine kinase inhibitor with anti-angiogenic effects used in metastatic colon cancer. Its most common side effects are fatigue, diarrhea and hypertension. However, severe neurologic toxicity has not been previously recognized. Here, we illustrate a case in which the patient developed hyperalgesia and radicular pain 2 weeks after starting regorafenib. Several studies report an increased neurological toxicity when angiogenesis inhibitors are given after <span class="hlt">radiation</span> therapy, and we postulate that the angioinhibitory effects of regorafenib accelerated subclinical microvascular injury from SBRT. This unexpected toxicity may be clinically relevant when giving targeted angiogenesis inhibitors after SBRT.</p> <div class="credits"> <p class="dwt_author">Tian, Sibo; Nissenblatt, Michael</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">386</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://openmed.nic.in/593/01/Satish_Kumar_M_2004_1.pdf"> <span id="translatedtitle">Effect of dicarbonyl-<span class="hlt">induced</span> browning on ?-<span class="hlt">crystallin</span> chaperone-like activity: physiological significance and caveats of in vitro aggregation assays</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">?-<span class="hlt">Crystallin</span> is a member of the small heat-shock protein family and functions like a molecular chaperone, and may thus help in maintainingthetransparencyoftheeyelensbyprotectingthelens proteins from various stress conditions. Non-enzymic glycation of long-lived proteins has been implicated in several age- and diabetes-related complications, including cataract. Dicarbonyl compounds such as methylglyoxal and glyoxal have been identifiedasthepredominantsourcefortheformationofadvanced glycation end-products in various tissues including the</p> <div class="credits"> <p class="dwt_author">Ira SUROLIA</p> <p class="dwt_publisher"></p> <p class="publishDate">2004-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">387</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/servlets/purl/5145933"> <span id="translatedtitle">Analysis of potential <span class="hlt">radiation-induced</span> genetic and somatic effects to man from milling of uranium</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">Potential mortality from natural causes and from <span class="hlt">radiation</span> exposure conditions typical of those in the vicinity of uranium mills in the western USA was calculated. The exposure conditions were those assumed to exist in the vicinity of a hypothetical model mill. Dose rates to organs at risk were calculated as a function of time using the Uranium Dispersion and Dosimetry Code (Momeni et al. 1979). The changes in population size, birth rates, and <span class="hlt">radiation-induced</span> and natural mortalities were calculated using the PRIM code (Momeni 1983). The population of the region within a radius of 80 km from the model mill is projected to increase from 57 428 to 75 638.6 during the 85 years of this analysis. Within the same period, the average birth rates for five-year periods increase from 5067.8 to 7436.1. The cumulative deaths within the five-year periods increase from 724 and 3501.8 from spontaneously <span class="hlt">induced</span> neoplasms and all causes, respectively, to 1538.2 and 6718.2. In comparison to natural causes, <span class="hlt">radiation-induced</span> mortality is negligible. The highest rate of death from <span class="hlt">radiation</span> in any five-year period is only 0.2, compared with 1538.2 deaths attributable to spontaneous incidence. The total <span class="hlt">radiation-induced</span> genetic disorders were much less than unity for the 85-year period of analysis, in contrast with the 10.7% natural incidence of these disorders.</p> <div class="credits"> <p class="dwt_author">Momeni, M.H.</p> <p class="dwt_publisher"></p> <p class="publishDate">1984-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">388</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2014SPIE.9040E..1BY"> <span id="translatedtitle">3D ultrasound Nakagami imaging for <span class="hlt">radiation-induced</span> vaginal fibrosis</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary"><span class="hlt">Radiation-induced</span> vaginal fibrosis is a debilitating side-effect affecting up to 80% of women receiving radiotherapy for their gynecological (GYN) malignancies. Despite the significant incidence and severity, little research has been conducted to identify the pathophysiologic changes of vaginal toxicity. In a previous study, we have demonstrated that ultrasound Nakagami shape and PDF parameters can be used to quantify <span class="hlt">radiation-induced</span> vaginal toxicity. These Nakagami parameters are derived from the statistics of ultrasound backscattered signals to capture the physical properties (e.g., arrangement and distribution) of the biological tissues. In this paper, we propose to expand this Nakagami imaging concept from 2D to 3D to fully characterize <span class="hlt">radiation-induced</span> changes to the vaginal wall within the <span class="hlt">radiation</span> treatment field. A pilot study with 5 post-radiotherapy GYN patients was conducted using a clinical ultrasound scanner (6 MHz) with a mechanical stepper. A serial of 2D ultrasound images, with radio-frequency (RF) signals, were acquired at 1 mm step size. The 2D Nakagami shape and PDF parameters were calculated from the RF signal envelope with a sliding window, and then 3D Nakagami parameter images were generated from the parallel 2D images. This imaging method may be useful as we try to monitor <span class="hlt">radiation-induced</span> vaginal injury, and address vaginal toxicities and sexual dysfunction in women after radiotherapy for GYN malignancies.</p> <div class="credits"> <p class="dwt_author">Yang, Xiaofeng; Rossi, Peter; Shelton, Joseph; Bruner, Debrorah; Tridandapani, Srini; Liu, Tian</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-03-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">389</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20040112350&hterms=breast+cancer&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D60%26Ntt%3Dbreast%2Bcancer"> <span id="translatedtitle"><span class="hlt">Radiation</span> <span class="hlt">induces</span> genomic instability and mammary ductal dysplasia in Atm heterozygous mice</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">Ataxia-telangiectasia (AT) is a genetic syndrome resulting from the inheritance of two defective copies of the ATM gene that includes among its stigmata radiosensitivity and cancer susceptibility. Epidemiological studies have demonstrated that although women with a single defective copy of ATM (AT heterozygotes) appear clinically normal, they may never the less have an increased relative risk of developing breast cancer. Whether they are at increased risk for <span class="hlt">radiation-induced</span> breast cancer from medical exposures to ionizing <span class="hlt">radiation</span> is unknown. We have used a murine model of AT to investigate the effect of a single defective Atm allele, the murine homologue of ATM, on the susceptibility of mammary epithelial cells to <span class="hlt">radiation-induced</span> transformation. Here we report that mammary epithelial cells from irradiated mice with one copy of Atm truncated in the PI-3 kinase domain were susceptible to <span class="hlt">radiation-induced</span> genomic instability and generated a 10% incidence of dysplastic mammary ducts when transplanted into syngenic recipients, whereas cells from Atm(+/+) mice were stable and formed only normal ducts. Since <span class="hlt">radiation-induced</span> ductal dysplasia is a precursor to mammary cancer, the results indicate that AT heterozygosity increases susceptibility to radiogenic breast cancer in this murine model system.</p> <div class="credits"> <p class="dwt_author">Weil, M. M.; Kittrell, F. S.; Yu, Y.; McCarthy, M.; Zabriskie, R. C.; Ullrich, R. L.</p> <p class="dwt_publisher"></p> <p class="publishDate">2001-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">390</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20040087961&hterms=dopamine&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Ddopamine"> <span id="translatedtitle">Brain signaling and behavioral responses <span class="hlt">induced</span> by exposure to (56)Fe-particle <span class="hlt">radiation</span></span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">Previous experiments have demonstrated that exposure to 56Fe-particle irradiation (1.5 Gy, 1 GeV) produced aging-like accelerations in neuronal and behavioral deficits. Astronauts on long-term space flights will be exposed to similar heavy-particle <span class="hlt">radiations</span> that might have similar deleterious effects on neuronal signaling and cognitive behavior. Therefore, the present study evaluated whether <span class="hlt">radiation-induced</span> spatial learning and memory behavioral deficits are associated with region-specific brain signaling deficits by measuring signaling molecules previously found to be essential for behavior [pre-synaptic vesicle proteins, synaptobrevin and synaptophysin, and protein kinases, calcium-dependent PRKCs (also known as PKCs) and PRKA (PRKA RIIbeta)]. The results demonstrated a significant <span class="hlt">radiation-induced</span> increase in reference memory errors. The increases in reference memory errors were significantly negatively correlated with striatal synaptobrevin and frontal cortical synaptophysin expression. Both synaptophysin and synaptobrevin are synaptic vesicle proteins that are important in cognition. Striatal PRKA, a memory signaling molecule, was also significantly negatively correlated with reference memory errors. Overall, our findings suggest that <span class="hlt">radiation-induced</span> pre-synaptic facilitation may contribute to some previously reported <span class="hlt">radiation-induced</span> decrease in striatal dopamine release and for the disruption of the central dopaminergic system integrity and dopamine-mediated behavior.</p> <div class="credits"> <p class="dwt_author">Denisova, N. A.; Shukitt-Hale, B.; Rabin, B. M.; Joseph, J. A.</p> <p class="dwt_publisher"></p> <p class="publishDate">2002-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">391</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20040087883&hterms=bystander+effect&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3Dbystander%2Beffect"> <span id="translatedtitle">Characterization of a novel epigenetic effect of ionizing <span class="hlt">radiation</span>: the death-<span class="hlt">inducing</span> effect</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">The detrimental effects associated with exposure to ionizing <span class="hlt">radiation</span> have long been thought to result from the direct targeting of the nucleus leading to DNA damage; however, the emergence of concepts such as <span class="hlt">radiation-induced</span> genomic instability and bystander effects have challenged this dogma. After cellular exposure to ionizing <span class="hlt">radiation</span>, we have isolated a number of clones of Chinese hamster-human hybrid GM10115 cells that demonstrate genomic instability as measured by chromosomal destabilization. These clones show dynamic and persistent generation of chromosomal rearrangements multiple generations after the original insult. We hypothesize that these unstable clones maintain this delayed instability phenotype by secreting factors into the culture medium. To test this hypothesis we transferred filtered medium from unstable cells to unirradiated GM10115 cells. No GM10115 cells were able to survive this medium. This phenomenon by which GM10115 cells die when cultured in medium from chromosomally unstable GM10115 clones is the death-<span class="hlt">inducing</span> effect. Medium transfer experiments indicate that a factor or factors is/are secreted by unstable cells within 8 h of growth in fresh medium and result in cell killing within 24 h. These factors are stable at ambient temperature but do not survive heating or freezing, and are biologically active when diluted with fresh medium. We present the initial description and characterization of the death-<span class="hlt">inducing</span> effect. This novel epigenetic effect of <span class="hlt">radiation</span> has implications for <span class="hlt">radiation</span> risk assessment and for health risks associated with <span class="hlt">radiation</span> exposure.</p> <div class="credits"> <p class="dwt_author">Nagar, Shruti; Smith, Leslie E.; Morgan, William F.</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">392</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4203326"> <span id="translatedtitle"><span class="hlt">Radiation-induced</span> signaling pathways that promote cancer cell survival (Review)</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary"><span class="hlt">Radiation</span> therapy is a staple cancer treatment approach that has significantly improved local disease control and the overall survival of cancer patients. However, its efficacy is still limited by the development of <span class="hlt">radiation</span> resistance and the presence of residual disease after therapy that leads to cancer recurrence. <span class="hlt">Radiation</span> impedes cancer cell growth by <span class="hlt">inducing</span> cytotoxicity, mainly caused by DNA damage. However, <span class="hlt">radiation</span> can also simultaneously <span class="hlt">induce</span> multiple pro-survival signaling pathways, such as those mediated by AKT, ERK and ATM/ATR, which can lead to suppression of apoptosis, induction of cell cycle arrest and/or initiation of DNA repair. These signaling pathways act conjointly to reduce the magnitude of <span class="hlt">radiation-induced</span> cytotoxicity and promote the development of radioresistance in cancer cells. Thus, targeting these pro-survival pathways has great potential for the radiosensitization of cancer cells. In the present review, we summarize the current literature on how these <span class="hlt">radiation</span>-activated signaling pathways promote cancer cell survival. PMID:25174607</p> <div class="credits"> <p class="dwt_author">HEIN, ASHLEY L.; OUELLETTE, MICHEL M.; YAN, YING</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">393</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/25174607"> <span id="translatedtitle"><span class="hlt">Radiation-induced</span> signaling pathways that promote cancer cell survival (Review).</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary"><span class="hlt">Radiation</span> therapy is a staple cancer treatment approach that has significantly improved local disease control and the overall survival of cancer patients. However, its efficacy is still limited by the development of <span class="hlt">radiation</span> resistance and the presence of residual disease after therapy that leads to cancer recurrence. <span class="hlt">Radiation</span> impedes cancer cell growth by <span class="hlt">inducing</span> cytotoxicity, mainly caused by DNA damage. However, <span class="hlt">radiation</span> can also simultaneously <span class="hlt">induce</span> multiple pro-survival signaling pathways, such as those mediated by AKT, ERK and ATM/ATR, which can lead to suppression of apoptosis, induction of cell cycle arrest and/or initiation of DNA repair. These signaling pathways act conjointly to reduce the magnitude of <span class="hlt">radiation-induced</span> cytotoxicity and promote the development of radioresistance in cancer cells. Thus, targeting these pro-survival pathways has great potential for the radiosensitization of cancer cells. In the present review, we summarize the current literature on how these <span class="hlt">radiation</span>?activated signaling pathways promote cancer cell survival. PMID:25174607</p> <div class="credits"> <p class="dwt_author">Hein, Ashley L; Ouellette, Michel M; Yan, Ying</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-11-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">394</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/12543783"> <span id="translatedtitle">Characterization of a novel epigenetic effect of ionizing <span class="hlt">radiation</span>: the death-<span class="hlt">inducing</span> effect.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">The detrimental effects associated with exposure to ionizing <span class="hlt">radiation</span> have long been thought to result from the direct targeting of the nucleus leading to DNA damage; however, the emergence of concepts such as <span class="hlt">radiation-induced</span> genomic instability and bystander effects have challenged this dogma. After cellular exposure to ionizing <span class="hlt">radiation</span>, we have isolated a number of clones of Chinese hamster-human hybrid GM10115 cells that demonstrate genomic instability as measured by chromosomal destabilization. These clones show dynamic and persistent generation of chromosomal rearrangements multiple generations after the original insult. We hypothesize that these unstable clones maintain this delayed instability phenotype by secreting factors into the culture medium. To test this hypothesis we transferred filtered medium from unstable cells to unirradiated GM10115 cells. No GM10115 cells were able to survive this medium. This phenomenon by which GM10115 cells die when cultured in medium from chromosomally unstable GM10115 clones is the death-<span class="hlt">inducing</span> effect. Medium transfer experiments indicate that a factor or factors is/are secreted by unstable cells within 8 h of growth in fresh medium and result in cell killing within 24 h. These factors are stable at ambient temperature but do not survive heating or freezing, and are biologically active when diluted with fresh medium. We present the initial description and characterization of the death-<span class="hlt">inducing</span> effect. This novel epigenetic effect of <span class="hlt">radiation</span> has implications for <span class="hlt">radiation</span> risk assessment and for health risks associated with <span class="hlt">radiation</span> exposure. PMID:12543783</p> <div class="credits"> <p class="dwt_author">Nagar, Shruti; Smith, Leslie E; Morgan, William F</p> <p class="dwt_publisher"></p> <p class="publishDate">2003-01-15</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">395</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4136475"> <span id="translatedtitle">PHD Inhibition Mitigates and Protects Against <span class="hlt">Radiation-Induced</span> Gastrointestinal Toxicity via HIF2</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary"><span class="hlt">Radiation-induced</span> gastrointestinal (GI) toxicity can be a major source of morbidity and mortality after <span class="hlt">radiation</span> exposure. There is an unmet need for effective preventative or mitigative treatments against the potentially fatal diarrhea and water loss <span class="hlt">induced</span> by <span class="hlt">radiation</span> damage to the GI tract. We report that prolyl hydroxylase inhibition by genetic knockout or pharmacologic inhibition of all PHD isoforms by the small molecule dimethyloxyallylglycine (DMOG) increases HIF expression, improves epithelial integrity, reduces apoptosis, and increases intestinal angiogenesis, all of which are essential for radioprotection. HIF2, but not HIF1, is both necessary and sufficient to prevent <span class="hlt">radiation-induced</span> GI toxicity and death. Increased VEGF expression contributes to the protective effects of HIF2, since inhibition of VEGF function reversed the radioprotection and radiomitigation afforded by DMOG. Additionally, mortality is reduced from abdominal or total body irradiation even when DMOG is given 24 hours after exposure. Thus, prolyl hydroxylase inhibition represents a new treatment strategy to protect against and mitigate GI toxicity from both therapeutic <span class="hlt">radiation</span> and potentially lethal <span class="hlt">radiation</span> exposures. PMID:24828078</p> <div class="credits"> <p class="dwt_author">Taniguchi, Cullen M.; Miao, Yu Rebecca; Diep, Anh N.; Wu, Colleen; Rankin, Erinn B.; Atwood, Todd F.; Xing, Lei; Giaccia, Amato J.</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">396</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013SPIE.8725E..1AP"> <span id="translatedtitle">Ion beam <span class="hlt">induced</span> charge analysis of <span class="hlt">radiation</span> damage in silicon photodiodes</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">The ion beam <span class="hlt">induced</span> charge (IBIC) technique is a valuable technique to study the degradation of the charge collection efficiency (CCE) <span class="hlt">induced</span> by <span class="hlt">radiation</span> damage in semiconductor devices. It offers the advantage of providing a wide range of damage levels generated by ions with different masses and energies in different regions of the same sample, and of using the same or different ions to probe the CCE degradation. This paper describes an experimental protocol based on IBIC and the relevant interpretative model, which includes the displacement damage dose approach as a special case and provides a general method to evaluate the effective <span class="hlt">radiation</span> hardness of a material.</p> <div class="credits"> <p class="dwt_author">Pastuovi?, Željko; Jakši?, Milko; Vittone, Ettore</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-05-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">397</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013SPIE.9044E..07W"> <span id="translatedtitle"><span class="hlt">Radiation-induced</span> transmission loss in low water peak single mode fibers</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary"><span class="hlt">Radiation-induced</span> transmission loss in Low Water Peak Single Mode (LWPSM) fiber has been investigated. Formation and conversion processes of defect centers also have been proposed using electron spin resonance in the fiber irradiated with gamma rays. When the irradiation dose is low, Germanium electron center (GEC) and self-trapped hole center (STH) occur. With the increase of dose, E' centers (Si and Ge) and nonbridge oxygen hole centers (NBOHCs) generate. With the help of thermal-bleaching or photo-bleaching, the <span class="hlt">radiation-induced</span> loss of pre-irradiation optical fiber can be reduced effectively. The obtain results also have been analyzed in detail.</p> <div class="credits"> <p class="dwt_author">Wang, Tingyun; Xiao, Zhongyin; Luo, Wenyun; Wen, Jianxiang; Yin, Jianchong; Wu, Wenkai; Gong, Renxiang</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-12-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">398</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013RaPC...84..242A"> <span id="translatedtitle">Antimicrobial fabric adsorbed iodine produced by <span class="hlt">radiation-induced</span> graft polymerization</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Antimicrobial fabric was synthesized by <span class="hlt">radiation-induced</span> graft polymerization of N-vinyl pyrrolidone onto polyolefine nonwoven fabric and subsequent adsorption of iodine. In response of the huge request for the antimicrobial material applied to face masks for swine flu in 2009, operation procedure of continuous <span class="hlt">radiation-induced</span> graft polymerization apparatus was improved. The improved grafting production per week increased 3.8 times compared to the production by former operation procedure. Shipped antimicrobial fabric had reached 130,000 m2 from June until December, 2009.</p> <div class="credits"> <p class="dwt_author">Aoki, Shoji; Fujiwara, Kunio; Sugo, Takanobu; Suzuki, Koichi</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-03-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">399</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://academic.research.microsoft.com/Publication/26394651"> <span id="translatedtitle"><span class="hlt">Radiation</span> <span class="hlt">induced</span> polarization in CdTe detectors</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Polarization <span class="hlt">induced</span> by irradiation with intense gamma ray sources has been studied in chlorine-compensated CdTe detectors. The influence of several parameters, such as applied field strength, temperature and incident photon flux, on the polarization effect have been investigated. A relationship was found between the degree of polarization, detector efficiency and detector leakage current.</p> <div class="credits"> <p class="dwt_author">D. Vartsky; M. Goldberg; Y. Eisen; Y. Shamai; R. Dukhan; P. Siffert; J. M. Koebel; R. Regal; J. Gerber</p> <p class="dwt_publisher"></p> <p class="publishDate">1988-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">400</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.springerlink.com/index/v7t3861581t80pw1.pdf"> <span id="translatedtitle"><span class="hlt">Radiation-induced</span> hyperdiploidy in Hyoscyamus niger L</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://academic.research.microsoft.com/">Microsoft Academic Search </a></p> <p class="result-summary">Summary A hyperdiploid plant type, approaching the triploid chromosome number, and representing possibly a high level of tetrasomy, was recorded in the progeny of a gamma ray-<span class="hlt">induced</span> unbranched desynaptic mutant in the M4 generation. Its meiotic behavior and its possible importance for deriving diverse hyperdiploid lines from desynaptic mutants are outlined.</p> <div class="credits"> <p class="dwt_author">U. C. Lavania; R. K. Lal; J. R. Sharma</p> <p class="dwt_publisher"></p> <p class="publishDate">1985-01-01</p> </div> </div> </div> </div> <div id="filter_results_form" class="filter_results_form floatContainer" style="visibility: visible;"> <div style="width:100%" id="PaginatedNavigation" class="paginatedNavigationElement"> <a id="FirstPageLink" onclick='return showDiv("page_1");' href="#" title="First Page"> <img id="FirstPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.first.18x20.png" alt="First Page" /></a> <a id="PreviousPageLink" onclick='return showDiv("page_19");' href="#" title="Previous Page"> <img id="PreviousPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.previous.18x20.png" alt="Previous Page" /></a> <span id="PageLinks" class="pageLinks"> <span> <a onClick='return showDiv("page_1");' href="#">1</a> <a onClick='return showDiv("page_2");' href="#">2</a> <a onClick='return showDiv("page_3");' href="#">3</a> <a onClick='return showDiv("page_4");' 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onclick='return showDiv("page_25.0");' href="#" title="Last Page"> <img id="LastPageLinkImage" class="Icon" src="http://www.science.gov/scigov/images/icon.last.18x20.png" alt="Last Page" /></a> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">401</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2013JPhCS.426a2034L"> <span id="translatedtitle">Proton <span class="hlt">induced</span> dielectron <span class="hlt">radiation</span> off Nb: Pt and Y distributions</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">Following our recent letter [1] on inclusive e+e- pair production in proton <span class="hlt">induced</span> reactions at Ekin = 3.5 GeV on the nucleus Nb, we present here in addition the transverse and rapidity distributions for various e+e- invariant mass bins and compare them to reference data measured in p+p reactions.</p> <div class="credits"> <p class="dwt_author">Lorenz, M.; Weber, M.; Agakishiev, G.; Behnke, C.; Belver, D.; Belyaev, A.; Berger-Chen, J. C.; Blanco, A.; Blume, C.; Böhmer, M.; Cabanelas, P.; Chernenko, S.; Dritsa, C.; Dybczak, A.; Epple, E.; Fabbietti, L.; Fateev, O.; Fonte, P.; Friese, J.; Fröhlich, I.; Galatyuk, T.; Garzón, J. A.; Gill, K.; Golubeva, M.; González-Díaz, D.; Guber, F.; Gumberidze, M.; Harabasz, S.; Hennino, T.; Holzmann, R.; Huck, P.; Hhne, C.; Ierusalimov, A.; Ivashkin, A.; Jurkovic, M.; Kämpfer, B.; Karavicheva, T.; Koenig, I.; Koenig, W.; Kolb, B. W.; Korcyl, G.; Kornakov, G.; Kotte, R.; Krása, A.; Krebs, E.; Krizek, F.; Kuc, H.; Kugler, A.; Kurepin, A.; Kurilkin, A.; Kurilkin, P.; Ladygin, V.; Lalik, R.; Lang, S.; Lapidus, K.; Lebedev, A.; Lopes, L.; Maier, L.; Mangiarotti, A.; Markert, J.; Metag, V.; Michel, J.; Müntz, C.; Münzer, R.; Naumann, L.; Palka, M.; Parpottas, Y.; Pechenov, V.; Pechenova, O.; Pietraszko, J.; Przygoda, W.; Ramstein, B.; Rehnisch, L.; Reshetin, A.; Rustamov, A.; Sadovsky, A.; Salabura, P.; Scheib, T.; Schuldes, H.; Siebenson, J.; Sobolev, Yu G.; Spataro, S.; Ströbele, H.; Stroth, J.; Strzempek, P.; Sturm, C.; Svoboda, O.; Tarantola, A.; Teilab, K.; Tlusty, P.; Traxler, M.; Tsertos, H.; Vasiliev, T.; Wagner, V.; Wendisch, C.; Wüstenfeld, J.; Yurevich, S.; Zanevsky, Y.; Hades Collaboration</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-03-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">402</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/25350386"> <span id="translatedtitle">Topological <span class="hlt">crystalline</span> insulator nanostructures.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Topological <span class="hlt">crystalline</span> insulators are topological insulators whose surface states are protected by the <span class="hlt">crystalline</span> symmetry, instead of the time reversal symmetry. Similar to the first generation of three-dimensional topological insulators such as Bi2Se3 and Bi2Te3, topological <span class="hlt">crystalline</span> insulators also possess surface states with exotic electronic properties such as spin-momentum locking and Dirac dispersion. Experimentally verified topological <span class="hlt">crystalline</span> insulators to date are SnTe, Pb1-xSnxSe, and Pb1-xSnxTe. Because topological protection comes from the crystal symmetry, magnetic impurities or in-plane magnetic fields are not expected to open a gap in the surface states in topological <span class="hlt">crystalline</span> insulators. Additionally, because they have a cubic structure instead of a layered structure, branched structures or strong coupling with other materials for large proximity effects are possible, which are difficult with layered Bi2Se3 and Bi2Te3. Thus, additional fundamental phenomena inaccessible in three-dimensional topological insulators can be pursued. In this review, topological <span class="hlt">crystalline</span> insulator SnTe nanostructures will be discussed. For comparison, experimental results based on SnTe thin films will be covered. Surface state properties of topological <span class="hlt">crystalline</span> insulators will be discussed briefly. PMID:25350386</p> <div class="credits"> <p class="dwt_author">Shen, Jie; Cha, Judy J</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-11-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">403</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://adsabs.harvard.edu/abs/2005PhRvL..94a6806I"> <span id="translatedtitle">Theoretical Approach to Microwave-<span class="hlt">Radiation-Induced</span> Zero-Resistance States in 2D Electron Systems</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p class="result-summary">We present a theoretical model in which the existence of <span class="hlt">radiation-induced</span> zero-resistance states is analyzed. An exact solution for the harmonic oscillator wave function in the presence of <span class="hlt">radiation</span>, and a perturbation treatment for elastic scattering due to randomly distributed charged impurities, form the foundations of our model. Following this model most experimental results are reproduced, including the formation of resistivity oscillations, their dependence on the intensity and frequency of the <span class="hlt">radiation</span>, temperature effects, and the locations of the resistivity minima. The existence of zero-resistance states is thus explained in terms of the interplay of the electron microwave-driven orbit dynamics and the Pauli exclusion principle.</p> <div class="credits"> <p class="dwt_author">Iñarrea, J.; Platero, G.</p> <p class="dwt_publisher"></p> <p class="publishDate">2005-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">404</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3941603"> <span id="translatedtitle">New era of radiotherapy: an update in <span class="hlt">radiation-induced</span> lung disease</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p class="result-summary">Over the last few decades, advances in radiotherapy (RT) technology have improved delivery of <span class="hlt">radiation</span> therapy dramatically. Advances in treatment planning with the development of image-guided radiotherapy and in techniques such as proton therapy, allows the <span class="hlt">radiation</span> therapist to direct high doses of <span class="hlt">radiation</span> to the tumour. These advancements result in improved local regional control while reducing potentially damaging dosage to surrounding normal tissues. It is important for radiologists to be aware of the radiological findings from these advances in order to differentiate expected <span class="hlt">radiation-induced</span> lung injury (RILD) from recurrence, infection, and other lung diseases. In order to understand these changes and correlate them with imaging, the radiologist should have access to the <span class="hlt">radiation</span> therapy treatment plans. PMID:23473474</p> <div class="credits"> <p class="dwt_author">Benveniste, M. F. K.; Welsh, J.; Godoy, M. C. B.; Betancourt, S. L.; Mawlawi, O. R; Munden, R. F.</p> <p class="dwt_publisher"></p> <p class="publishDate">2014-01-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">405</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://ntrs.nasa.gov/search.jsp?R=20050193746&hterms=BIODOSIMETRY&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3DBIODOSIMETRY"> <span id="translatedtitle">Simultaneous measurement of multiple <span class="hlt">radiation-induced</span> protein expression profiles using the Luminex(TM) system</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p class="result-summary">Space flight results in the exposure of astronauts to a mixed field of <span class="hlt">radiation</span> composed of energetic particles of varying energies, and biological indicators of space <span class="hlt">radiation</span> exposure provides a better understanding of the associated long-term health risks. Current methods of biodosimetry have employed the use of cytogenetic analysis for biodosimetry, and more recently the advent of technological progression has led to advanced research in the use of genomic and proteomic expression profiling to simultaneously assess biomarkers of <span class="hlt">radiation</span> exposure. We describe here the technical advantages of the Luminex(TM) 100 system relative to traditional methods and its potential as a tool to simultaneously profile multiple proteins <span class="hlt">induced</span> by ionizing <span class="hlt">radiation</span>. The development of such a bioassay would provide more relevant post-translational dynamics of stress response and will impart important implications in the advancement of space and other <span class="hlt">radiation</span> contact monitoring. c2004 COSPAR. Published by Elsevier Ltd. All rights reserved.</p> <div class="credits"> <p class="dwt_author">Desai, N.; Wu, H.; George, K.; Gonda, S. R.; Cucinotta, F. A.; Cucniotta, F. A. (Principal Investigator)</p> <p class="dwt_publisher"></p> <p class="publishDate">2004-01-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">406</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.ncbi.nlm.nih.gov/pubmed/23473474"> <span id="translatedtitle">New era of radiotherapy: an update in <span class="hlt">radiation-induced</span> lung disease.</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p class="result-summary">Over the last few decades, advances in radiotherapy (RT) technology have improved delivery of <span class="hlt">radiation</span> therapy dramatically. Advances in treatment planning with the development of image-guided radiotherapy and in techniques such as proton therapy, allows the <span class="hlt">radiation</span> therapist to direct high doses of <span class="hlt">radiation</span> to the tumour. These advancements result in improved local regional control while reducing potentially damaging dosage to surrounding normal tissues. It is important for radiologists to be aware of the radiological findings from these advances in order to differentiate expected <span class="hlt">radiation-induced</span> lung injury (RILD) from recurrence, infection, and other lung diseases. In order to understand these changes and correlate them with imaging, the radiologist should have access to the <span class="hlt">radiation</span> therapy treatment plans. PMID:23473474</p> <div class="credits"> <p class="dwt_author">Benveniste, M F K; Welsh, J; Godoy, M C B; Betancourt, S L; Mawlawi, O R; Munden, R F</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-06-01</p> </div> </div> </div> </div> <div class="floatContainer result odd" lang="en"> <div class="resultNumber element">407</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="http://science.gov/scigov/link.html?type=RESULT&redirectUrl=http://www.osti.gov/scitech/biblio/22224496"> <span id="translatedtitle">Sorafenib Enhances <span class="hlt">Radiation-Induced</span> Apoptosis in Hepatocellular Carcinoma by Inhibiting STAT3</span></a>  </p> <div class="result-meta"> <p class="source"><a target="_blank" id="logoLink" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p class="result-summary">Purpose: Hepatocellular carcinoma (HCC) is one of the most common and lethal human malignancies. Lack of efficient therapy for advanced HCC is a pressing problem worldwide. This study aimed to determine the efficacy and mechanism of combined sorafenib and <span class="hlt">radiation</span> therapy treatment for HCC. Methods and Materials: HCC cell lines (PLC5, Huh-7, Sk-Hep1, and Hep3B) were treated with sorafenib, <span class="hlt">radiation</span>, or both, and apoptosis and signal transduction were analyzed. Results: All 4 HCC cell lines showed resistance to <span class="hlt">radiation-induced</span> apoptosis; however, this resistance could be reversed in the presence of sorafenib. Inhibition of phospho-STAT3 was found in cells treated with sorafenib or sorafenib plus <span class="hlt">radiation</span> and subsequently reduced the expression levels of STAT3-related proteins, Mcl-1, cyclin D1, and survivin. Silencing STAT3 by RNA interference overcame apoptotic resistance to <span class="hlt">radiation</span> in HCC cells, and the ectopic expression of STAT3 in HCC cells abolished the radiosensitizing effect of sorafenib. Moreover, sorafenib plus <span class="hlt">radiation</span> significantly suppressed PLC5 xenograft tumor growth. Conclusions: These results indicate that sorafenib sensitizes resistant HCC cells to <span class="hlt">radiation-induced</span> apoptosis via downregulating phosphorylation of STAT3 in vitro and in vivo.</p> <div class="credits"> <p class="dwt_author">Huang, Chao-Yuan [Department of Oncology, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan (China) [Department of Oncology, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan (China); Department of Radiological Technology, Yuanpei University, Hsinchu, Taiwan (China); Lin, Chen-Si [School of Veterinary Medicine, National Taiwan University Hospital, Taipei, Taiwan (China)] [School of Veterinary Medicine, National Taiwan University Hospital, Taipei, Taiwan (China); Tai, Wei-Tien; Hsieh, Chi-Ying [Department of Medical Research, National Taiwan University Hospital, Taipei, Taiwan (China) [Department of Medical Research, National Taiwan University Hospital, Taipei, Taiwan (China); National Center of Excellence for Clinical Trial and Research, National Taiwan University Hospital, Taipei, Taiwan (China); Shiau, Chung-Wai [Institute of Biopharmaceutical Sciences, National Yang-Ming University, Taipei, Taiwan (China)] [Institute of Biopharmaceutical Sciences, National Yang-Ming University, Taipei, Taiwan (China); Cheng, Ann-Lii [Department of Oncology, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan (China) [Department of Oncology, National Taiwan University Hospital and National Taiwan University College of Medicine, Taipei, Taiwan (China); National Center of Excellence for Clinical Trial and Research, National Taiwan University Hospital, Taipei, Taiwan (China); Chen, Kuen-Feng, E-mail: kfchen1970@ntu.edu.tw [Department of Medical Research, National Taiwan University Hospital, Taipei, Taiwan (China) [Department of Medical Research, National Taiwan University Hospital, Taipei, Taiwan (China); National Center of Excellence for Clinical Trial and Research, National Taiwan University Hospital, Taipei, Taiwan (China)</p> <p class="dwt_publisher"></p> <p class="publishDate">2013-07-01</p> </div> </div> </div> </div> <div class="floatContainer result " lang="en"> <div class="resultNumber element">408</div> <div class="resultBody element"> <p class="result-title"><a target="resultTitleLink" href="ht