Radiation effects on crystalline polymers—I. Gamma-radiation-induced crosslinking and structural characterization of polyethylene oxide

Levels of the tumor suppressor protein p53 are normally quite low due in part to its short half-life. p53 levels increase in cells exposed to DNA-damaging agents, such as radiation, and this increase is thought to be responsible for the radiation-induced G1 cell cycle arrest or delay. The mechanisms by which radiation causes an increase in p53 are currently unknown. The purpose of this study was to compare the effects of gamma and UV radiation on the stability and ubiquitination of p53 in vivo. Ubiquitin-p53 conjugates could be detected in nonirradiated and gamma-irradiated cells but not in cells which were UV treated, despite the fact that both treatments resulted in the stabilization of the p53 protein. These results demonstrate that UV and gamma radiation have different effects on ubiquitinated p53 and suggest that the UV-induced stabilization of p53 results from a loss of p53 ubiquitination. Ubiquitinated forms of p21, an inhibitor of cyclin-dependent kinases, were detected in vivo, demonstrating that p21 is also a target for degradation by the ubiquitin-dependent proteolytic pathway. However, UV and gamma radiation had no effect on the stability or in vivo ubiquitination of p21, indicating that the radiation effects on p53 are specific.

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On-Line Characterization of Gamma Radiation Effects on Single-Ended Raman Based Distributed Fiber Optic Sensor

IEEE Transactions on Nuclear Science ◽

10.1109/tns.2016.2528584 ◽

2016 ◽

Vol 63 (4) ◽

pp. 2051-2057 ◽

Cited By ~ 5

Author(s):

C. Cangialosi ◽

S. Girard ◽

M. Cannas ◽

A. Boukenter ◽

E. Marin ◽

...

Keyword(s):

Gamma Radiation ◽

Radiation Effects ◽

Fiber Optic ◽

Fiber Optic Sensor ◽

Optic Sensor ◽

Distributed Fiber Optic Sensor ◽

On Line

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Ionizing Radiation Effects on Interfaces in Carbon Nanotube-Polymer Composites

MRS Proceedings ◽

10.1557/proc-697-p9.7 ◽

2001 ◽

Vol 697 ◽

Cited By ~ 4

Author(s):

Julie P. Harmon ◽

Patricia Anne O. Muisener ◽

LaNetra Clayton ◽

John D'Angelo ◽

Arun K. Sikder ◽

...

Keyword(s):

Carbon Nanotube ◽

Gamma Radiation ◽

Total Dose ◽

Dose Rate ◽

Polymer Composites ◽

Radiation Effects ◽

Mechanical Analysis ◽

Scanning Calorimetry ◽

Radiation Induced ◽

Radiation Induced Chemistry

AbstractThe purpose of this research was to probe nanotube-polymer composites for evidences of radiation induced chemistry at the interface of the host polymer and the nanotube structures. Single wall carbon nanotube (SWNT) / poly (methyl methacrylate) (PMMA) composites were fabricated and exposed to gamma radiation with a Co60 source at a dose rate of 1.28 X 106 rad/hour in an air environment for a total dose of 5.9 Mrads. Neat nanotube paper and neat PMMA were also exposed. Spun coat films of SWNT/PMMA were exposed to gamma radiation with a Ce157at a dose rate of 4.46 x 103 rad/hr for a total dose of 3.86 Mrads. Both irradiated and non-irradiated samples were compared. Glass transition temperatures were characterized by differential scanning calorimetry. Dynamic mechanical analysis and dielectric analysis evidenced changes in relaxations induced by irradiation. Irradiated composites exhibited radiation induced chemistry distinct from degradation effects noted in the pure polymer. Scanning electron microscopy provided images of the SWNTs and SWNT/PMMA interface before and after irradiation. This investigation imparts insight into the nature of radiation induced events in nanotubes and nanocomposites.

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