Radiation-induced decomposition of the tributyl phosphate-nitric acid system: Role of nitric acid

1992 ◽  
Vol 166 (5) ◽  
pp. 421-429 ◽  
Author(s):  
M. V. Krishnamurthy ◽  
R. Sampathkumar
Keyword(s):  
Nitric Acid ◽  
Tributyl Phosphate ◽  
Acid System ◽  
Radiation Induced ◽  
Induced Decomposition

Phosphonates as alternative to tributyl phosphate for the separation of actinides from fission products

2015 ◽  
Vol 103 (4) ◽  
Author(s):  
Chirag K. Vyas ◽  
C. V. S. Brahmmananda Rao ◽  
S. Jayalakshmi ◽  
Pranav M. Joshirao ◽  
Vijay K. Manchanda
Keyword(s):  
Nitric Acid ◽  
Solvent Extraction ◽  
Tributyl Phosphate ◽  
Fission Products ◽  
Nitric Acid Medium ◽  
Extraction Behavior ◽  
Separation Factors ◽  
Phosphoryl Oxygen ◽  
Better Than

AbstractThe present work investigates the role of increase in the basicity of organophosphorus extractant (dialkylalkyl phosphonates) on the uptake of actinides and fission products vis-à-vis tributyl phosphate (TBP), currently employed as a universal extractant. Two dialkylalkyl phosphonates viz. dibutylpropyl phosphonate (DBPrP) and dibutylpentyl phosphonate (DBPeP) were synthesized, characterized and evaluated for their solvent extraction behavior towards U(VI), Th(IV), Eu(III) and Tc(VII) in nitric acid medium ranging from 0.01–6 M. It was observed that increasing the basicity of the phosphoryl oxygen enhanced the uptake of the actinides and the distribution coefficient values were significantly larger as compared to TBP. The limiting organic concentration (LOC) value was estimated for Th(IV) for these extractants and compared with the TBP system. The separation factors of actinides with phosphonates over Tc(VII) are distinctly better than that with TBP.

α-Radiolysis of the tributyl phosphate–hydrocarbon diluent–nitric acid system

2016 ◽  
Vol 58 (2) ◽  
pp. 188-202 ◽  
Author(s):  
B. Ya. Zilberman ◽  
V. M. Chistyakov
Keyword(s):  
Nitric Acid ◽  
Tributyl Phosphate ◽  
Acid System

RADIATION-INDUCED DECOMPOSITION AND POLYMERIZATION OF POLYVINYL ALCOHOL IN AQUEOUS SOLUTIONS

2013 ◽  
Vol 12 (7) ◽  
pp. 1323-1328 ◽  
Author(s):  
Lujun Chen ◽  
Weihua Sun ◽  
Jinping Tian ◽  
Jianlong Wang ◽  
Shijun He
Keyword(s):  
Polyvinyl Alcohol ◽  
Aqueous Solutions ◽  
Radiation Induced ◽  
Induced Decomposition

Histologic Findings of Choroidal Vasculopathy in Eyes Enucleated following Radiation Therapy for Uveal Melanoma: Radiation Choroidopathy

2021 ◽  
Author(s):  
Sean Platt ◽  
Diva R. Salomao ◽  
Jose Pulido
Keyword(s):  
Radiation Therapy ◽  
Uveal Melanoma ◽  
Malignant Tumors ◽  
Vitreous Hemorrhage ◽  
Radiation Retinopathy ◽  
Radiation Induced ◽  
Histopathologic Analysis ◽  
Choroidal Vessels ◽  
Choroidal Vasculopathy

Abstract Introduction Little has been published about the choroidal vascular changes that occur years after radiation exposure. The aim of this study was to review the histological changes observed in the choroidal vasculature following radiotherapy for uveal melanoma. Methods Records from a single institution were retrospectively reviewed from June 7, 2007 to June 7, 2017; 101 patients with a diagnosis of uveal melanoma that underwent enucleation had their records reviewed. Out of these, a total of 26 eyes had undergone plaque brachytherapy prior to enucleation, which had been performed at a mean time of 7.2 years (range from 0 years to 30 years) after the initial plaque placement. A histopathologic analysis was conducted on all 26 eyes with special emphasis on the choroidal changes. Of these 26 eyes, 18 demonstrated evidence of radiation-induced vasculopathy. Results Of the 18 eyes, 10/18 (55%) had radiation retinopathy and 16/18 (89%) had radiation choroidal vasculopathy. One patient had a phthisical eye, and the choroid could not be evaluated because the characteristics of the vasculature could not be determined. Nine cases had vitreous hemorrhage (50%), all cases had radiation retinopathy, and 8/9 (89%) had radiation choroidopathy. Of the 16 cases with radiation choroidal vasculopathy, 3/16 (19%) had only intratumoral radiation choroidal vasculopathy, 3/16 (19%) had only extratumoral radiation choroidal vasculopathy, and, thus, 10/16 (32%) had both intratumoral and extratumoral radiation choroidal vasculopathy. In patients with radiation choroidal vasculopathy, 2/16 (13%) had hyalinization of the choroidal vessels. Another 3/16 (19%) cases with radiation choroidal vasculopathy had ectatic vessels. The other 11/16 (68%) had evidence of both hyalinization of the choroidal vessels as well as ectatic vessels in the choroid. Histological evidence of radiation retinopathy and choroidopathy were seen in 69% of eyes enucleated after receiving radiation therapy, which, in some cases, also had vitreous hemorrhage. Polypoidal choroidal vasculopathy, choroidal neovascularization, and retinal choroidal anastomoses (RAP-type lesions) were seen in 12 of the 16 eyes (75%). Discussion/Conclusion Irradiation of malignant tumors of the eye causes not only radiation retinopathy but also radiation choroidopathy. The role of radiation choroidopathy in the subsequent visual loss following radiotherapy and the role of anti-VEGF therapy needs to be recognized and distinguished from radiation retinopathy. Our data adds to the prior limited knowledge that radiation affects the choroid and can induce specific phenotypes similar to the clinical spectrum of CNV, PCV, and RAP.

scholarly journals Space Radiation-Induced Alterations in the Hippocampal Ubiquitin-Proteome System

2021 ◽  
Vol 22 (14) ◽  
pp. 7713
Author(s):  
Alyssa Tidmore ◽  
Sucharita M. Dutta ◽  
Arriyam S. Fesshaye ◽  
William K. Russell ◽  
Vania D. Duncan ◽  
...  
Keyword(s):  
Spatial Memory ◽  
Memory Performance ◽  
Space Radiation ◽  
Label Free ◽  
Proteomic Profiling ◽  
Neurocognitive Deficits ◽  
Male Wistar Rats ◽  
Radiation Induced ◽  
Induced Changes

Exposure of rodents to <20 cGy Space Radiation (SR) impairs performance in several hippocampus-dependent cognitive tasks, including spatial memory. However, there is considerable inter-individual susceptibility to develop SR-induced spatial memory impairment. In this study, a robust label-free mass spectrometry (MS)-based unbiased proteomic profiling approach was used to characterize the composition of the hippocampal proteome in adult male Wistar rats exposed to 15 cGy of 1 GeV/n 48Ti and their sham counterparts. Unique protein signatures were identified in the hippocampal proteome of: (1) sham rats, (2) Ti-exposed rats, (3) Ti-exposed rats that had sham-like spatial memory performance, and (4) Ti-exposed rats that impaired spatial memory performance. Approximately 14% (159) of the proteins detected in hippocampal proteome of sham rats were not detected in the Ti-exposed rats. We explored the possibility that the loss of the Sham-only proteins may arise as a result of SR-induced changes in protein homeostasis. SR-exposure was associated with a switch towards increased pro-ubiquitination proteins from that seen in Sham. These data suggest that the role of the ubiquitin-proteome system as a determinant of SR-induced neurocognitive deficits needs to be more thoroughly investigated.

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