Effects of γ irradiation on bis(2-ethylhexyl)phosphoric acid supported by macroporous silica-based polymeric resins

2018 ◽  
Vol 106 (3) ◽  
pp. 249-258 ◽  
Author(s):  
Qiding Shu ◽  
Afshin Khayambashi ◽  
Xinpeng Wang ◽  
Xiaolong Wang ◽  
Lei Feng ◽  
...  
Keyword(s):  
Phosphoric Acid ◽  
Fuel Cycle ◽  
Solid Phase ◽  
Absorbed Dose ◽  
Γ Irradiation ◽  
Macroporous Silica ◽  
Before And After ◽  
Radiation Resistant ◽  
Γ Rays ◽  
Polymeric Resins

AbstractBis(2-ethylhexyl)phosphoric acid (HDEHP) is one of the most intensively used extractants in solvent extraction, and its particular interest lies in the its application in nuclear fuel cycle as an extractant supported by macroporous silica-based polymeric resins in solid phase extraction technique. In this study, HDEHP/SiO2-P was synthesized by impregnation and immobilization, and we mainly focused on its radiation-resistant properties against γ-rays. It was found that HDEHP/SiO2-P still had good adsorption and separation properties after γ-irradiation by batch experiment. The uptake capacity of Gd(III) towards HDEHP/SiO2-P decreased slightly after irradiation. HDEHP/SiO2-P did not show any changes in the characterization of infrared spectroscopy and thermogravimetric analysis before and after irradiation. UPLC-Q-TOF-MS was employed to investigate the reaction mechanism in radiolysis of HDEHP in irradiated filter liquor. HDEHP/SiO2-P had a satisfactory radiation-resistance and chemical stability, even though it was exposed to the high absorbed dose of 500 kGy by γ-rays.

scholarly journals Studies on adsorption of rare earth elements from nitric acid solution with macroporous silica-based bis(2-ethylhexyl)phosphoric acid impregnated polymeric adsorbent

2018 ◽  
Vol 36 (3-4) ◽  
pp. 1049-1065 ◽  
Author(s):  
Qiding Shu ◽  
Afshin Khayambashi ◽  
Xinpeng Wang ◽  
Yuezhou Wei
Keyword(s):  
Rare Earth ◽  
Nitric Acid ◽  
Phosphoric Acid ◽  
Rare Earth Elements ◽  
Solid Phase ◽  
Macroporous Silica ◽  
Different Temperatures ◽  
Heavy Rare Earth Elements ◽  
Increasing Temperature ◽  
Light Rare Earth Elements

For the adsorption and recovery of rare earth elements from aqueous nitric acid, solid-phase extraction resins were prepared by impregnating and immobilizing of bis(2-ethylhexyl)phosphoric acid extractant into the macroporous silica-based polymeric (SiO2-P) particles. It was found that bis(2-ethylhexyl)phosphoric acid/SiO2-P had higher adsorption distribution coefficient for heavy rare earth elements than for light rare earth elements. The adsorption capacity of Gd(III) was observed to be 0.315 mmol g−1 by bis(2-ethylhexyl)phosphoric acid/SiO2-P in 0.1 M HNO3 at 298 K, which increased slightly when increasing temperature from 298 to 323 K. The adsorption isotherms of Gd(III) matched well with the Langmuir and Freundlich models. The obtained thermodynamic parameters (ΔHo and ΔGo) showed that the adsorption of Gd(III) by bis(2-ethylhexyl)phosphoric acid/SiO2-P was a spontaneous and exothermic process. This study also evaluated the chemical stability of bis(2-ethylhexyl)phosphoric acid/SiO2-P treated with nitric acid at different temperatures and demonstrated that bis(2-ethylhexyl)phosphoric acid/SiO2-P had considerable stability against nitric acid and heat.

scholarly journals DNA Damage Changes Distribution Pattern and Levels of HP1 Protein Isoforms in the Nucleolus and Increases Phosphorylation of HP1β-Ser88

Cells ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 1097 ◽  
Author(s):  
Legartová ◽  
Lochmanová ◽  
Zdráhal ◽  
Kozubek ◽  
Šponer ◽  
...  
Keyword(s):  
Dna Damage ◽  
Regulation Of Gene Expression ◽  
Protein Isoforms ◽  
28S Rrna ◽  
Heterochromatin Protein 1 ◽  
Γ Irradiation ◽  
Γ Radiation ◽  
The Family ◽  
Before And After ◽  
Γ Rays

The family of heterochromatin protein 1 (HP1) isoforms is essential for chromatin packaging, regulation of gene expression, and repair of damaged DNA. Here we document that γ-radiation reduced the number of HP1α-positive foci, but not HP1β and HP1γ foci, located in the vicinity of the fibrillarin-positive region of the nucleolus. The additional analysis confirmed that γ-radiation has the ability to significantly decrease the level of HP1α in rDNA promoter and rDNA encoding 28S rRNA. By mass spectrometry, we showed that treatment by γ-rays enhanced the HP1β serine 88 phosphorylation (S88ph), but other analyzed modifications of HP1β, including S161ph/Y163ph, S171ph, and S174ph, were not changed in cells exposed to γ-rays or treated by the HDAC inhibitor (HDACi). Interestingly, a combination of HDACi and γ-radiation increased the level of HP1α and HP1γ. The level of HP1β remained identical before and after the HDACi/γ-rays treatment, but HDACi strengthened HP1β interaction with the KRAB-associated protein 1 (KAP1) protein. Conversely, HP1γ did not interact with KAP1, although approximately 40% of HP1γ foci co-localized with accumulated KAP1. Especially HP1γ foci at the periphery of nucleoli were mostly absent of KAP1. Together, DNA damage changed the morphology, levels, and interaction properties of HP1 isoforms. Also, γ-irradiation-induced hyperphosphorylation of the HP1β protein; thus, HP1β-S88ph could be considered as an important marker of DNA damage.

scholarly journals RECEIVING RADIATION-RESISTANT MATERIAL BY SHS METHOD

2018 ◽  
Vol 14 (4) ◽  
pp. 49-57
Author(s):  
N Ya Bikberdina ◽  
M Yu Kozhanova ◽  
A A Kozhanov ◽  
I S Golubenko ◽  
M P Boronenko ◽  
...  
Keyword(s):  
Absorbed Dose ◽  
Video Camera ◽  
Synthesis Process ◽  
Reaction Products ◽  
Resistant Material ◽  
Before And After ◽  
First Results ◽  
Radiation Resistant ◽  
Shs Method

All The first results of obtaining radiation-resistant material by the SHS method are presented in the article. Synthesis of material based on the system Fe2O3-Al-Cr2O3-MoO3-Ti. The resulting material was irradiated with an electron beam of 1.8 MeV. The synthesis process was filmed by an action video camera. Fourier image analysis revealed the instability of combustion regimes and predicted the quality of reaction products. A comparative analysis of the microstructure of the samples before and after irradiation with electrons confirmed the results of the FFT. Despite the relatively low quality of the synthesis products, the embrittlement occurred at the absorbed dose of 70 Mrad. In the future, it is planned to improve the methodology for identifying unstable synthesis modes and adjusting the percentage ratio of the charge components.

ANALYSIS OF RADIOIMMUNOASSAY BY DISC ELECTROPHORESIS AND SUCROSE GRADIENT CENTRIFUGATION

1971 ◽  
Vol 66 (2) ◽  
pp. 257-265 ◽  
Author(s):  
Lubomir Valenta ◽  
Michel L. Aubert
Keyword(s):  
Sucrose Gradient ◽  
Solid Phase ◽  
Gradient Centrifugation ◽  
Human Growth ◽  
Disc Electrophoresis ◽  
Separate Analysis ◽  
Adrenocorticotrophic Hormone ◽  
Sucrose Gradient Centrifugation ◽  
Before And After ◽  
Polypeptide Hormones

ABSTRACT Radioiodine-labelled synthetic adrenocorticotrophic hormone (ACTH), human growth hormone (HGH), human chorionic somato-mammotrophin (HCS), and human (HTSH) and bovine (BTSH) thyroid stimulating hormones were studied by disc-electrophoresis and sucrose gradient centrifugation before and after incubation with corresponding antisera. All antisera contained 7 S antibodies. After incubation, soluble antigenantibody complexes besides a small amount of precipitate were observed in the incubation mixture, characteristic of each hormone. The complexes migrated like gamma globulins or more slowly on disc-electrophoresis. and on sucrose gradient centrifugation showed patterns dependent on the time of incubation. Light 7 or 9 S, or < 12 S complexes occurred mostly after incubation for several minutes (up to 30 min) before analysis. When incubation was prolonged to 24 h and more, these relatively light complexes disappeared or diminished in favour of heavier soluble or precipitating complexes. Reproducibly obtainable sedimentation patterns of the soluble complexes suggested some definite recombination of antigen molecules with 7 S antibodies. The complexes did not occur on incubation with other sera than an antiserum to a given hormone. They were not influenced by EDTA. Displacement of the radioactivity of the complexes into the free hormone peak was obtained by addition of a non-labelled hormone identical with the labelled one. Sucrose gradient centrifugation and disc-electrophoresis are recommended for the study of immunoreaction of diluted materials and for a separate analysis of different steps of the radioimmunoassay. Radioimmunoassay was introduced for the measurement of protein hormones by Yalow & Berson (1960). The method, described originally for insulin, was later adapted to the detection of a number of protein and polypeptide hormones. On incubation of the hormone with its antiserum, a soluble antigenantibody complex is formed, which is separated from an excess of the free hormone by various methods, e. g. chromatoelectrophoresis, precipitation with a second antibody, adsorption on a solid phase etc. (Hunter 1967). Sucrose gradient centrifugation and disc-electrophoresis were occasionally used to follow some isolated aspect of radioimmunoassay (Fitschen 1965; Monjardino et al. 1968). We are demonstrating that these methods made it possible to analyze the radioimmunoassay step by step and thus may be useful for practical purposes as well as in a study of the immunoreaction of diluted materials.

Skin exposure: requirements to methods determining active ingredient of pesticides in washings

2019 ◽  
pp. 43-48
Author(s):  
V. N. Rakitskii ◽  
N. E. Fedorova ◽  
I. V. Bereznyak ◽  
N. G. Zavolokina ◽  
L. P. Muhina
Keyword(s):  
Lower Limit ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Absorbed Dose ◽  
Ambient Air ◽  
Safety Coefficient ◽  
Limit Value ◽  
Calculated Risk ◽  
Nature Studies ◽  
Active Substances

The article presents results of studies exemplified by diquat on analysis concerning influence of lower limit value of quantitative assessment in washing sample for safety coefficient in exposure and in absorbed dose, if acting substance is absent in workplace ambient air samples and in dermal washings of workers. To control diquat in dermal washings, there is a method based on ion-pair liquid chromatography with ultraviolet detection (working wavelength 310 nm). To concentrate sample, cartridges for solid-phase extraction, containing ion exchange sorbent (Oasis MCX 6cc/500 mg), are used. Lower limit of assessment in washing sample — 0,15 micrograms. Experimentally set washing completeness is within range of 80–92%, standard deviation of repetition is 7,0% at most. The method created was tested in nature studies determining dermal exposure in workers subjected to 5 various preparations based on diquat dibromide when used for surface spraying from tractor and from aircraft. For lower limit of detection in washing sample (0,15 micrograms/washing), calculated risk value of exposure varied within 0,26–0,36; risk of absorbed dose was low — 0,23 (the allowable one ≤1). Findings are that present measuring methods which provide lower limit of detection 1 and 5 micrograms in washing sample could result in unallowable risk establishment even with absence of the substance in all samples of workplace air and dermal washings. The calculation formula suggested enables to give theoretic basis for requirements to lower limit of detecting active substances in dermal washing samples for evaluating risk of pesticides use in agriculture.

Photolytic and thermal annealing of radical anions gamma-irradiated monocarboxylic acids

1979 ◽  
Vol 44 (12) ◽  
pp. 3632-3643 ◽  
Author(s):  
Karel Mach ◽  
Igor Janovský ◽  
Karel Vacek
Keyword(s):  
Thermal Annealing ◽  
Pivalic Acid ◽  
Esr Spectra ◽  
Paramagnetic Species ◽  
Radical Anions ◽  
Γ Irradiation ◽  
Before And After ◽  
Optical Bleaching ◽  
The Difference ◽  
Gamma Irradiated

Total yields of paramagnetic species, their optical bleaching and thermal annealing in acetic, propionic, a-butyric, isobutyric, and pivalic acid γ-irradiated at 77 K were followed by ESR spectroscopy. Radical anions, always found after irradiation, disappear during optical bleaching without formation of any paramagnetic product. During thermal annealing they are converted almost quantitatively into the α-radicals of the respective acid, with the exception of pivalic acid. Amounts of radical anions were estimated from the difference of integrated ESR spectra taken before and after optical bleaching. The results show that approximately equal amounts of the reduction and oxidation paramagnetic products of the γ-irradiation can be detected.

Comparative Study on Compositions of Oil-Water Transition Layer before and after ClO2-Treatment Process

2013 ◽  
Vol 652-654 ◽  
pp. 749-752
Author(s):  
Dan Dan Yuan ◽  
Hong Jun Wu ◽  
Hai Xia Sheng ◽  
Xin Sui ◽  
Bao Hui Wang
Keyword(s):  
Chemical Composition ◽  
Transition Layer ◽  
Solid Phase ◽  
Settling Tank ◽  
Physical Structure ◽  
Solid Particles ◽  
Viscosity Reduction ◽  
Insoluble Residue ◽  
Before And After ◽  
Oil Water

In order to meet the need of separating oil from water in the settling tank of the oilfield, ClO2 treatment for oil-water transition layer in settling tank is introduced. The field test displayed that the technique was achieved by a good performance. For understanding the oxidation and mechanism, compositions of oil-water transition layer were comparatively studied for before/after ClO2-treatment in this paper.The experimental results show that the compositions before and after ClO2-treatment, including physical structure and chemical composition, were varied in the great extension. The physical structure, consisting of water, oil and solid phase, was reduced to less than 5% of water and 0.5% of solid particle and increased to 95% of oil in layer compared with before-treatment, easily leading to clearly separating water from oil. The chemical composition of iron sulfide and acid insoluble substance in solid phase was decreased to more than 90% while the carbonate was reduced more than 70% . After the treatment, the viscosity reduction of the water phase in the layer was reached to 50% after oxidation demulsification with ClO2. The chemistry was discussed based on the principles and experiments. Due to ClO2 destroying (oxidizing) the rigid interface membrane structure which is supported by natural surfactant, polymer and solid particles with interface-active materials, the action accelerates the separating of water and oil and sedimentation of insoluble residue of acid in the layer. By demonstrating the experimental data and discussion, we can effectively control the oxidation performance of chlorine dioxide, which is very meaningful for oilfield on the aspect of stable production of petroleum.

scholarly journals Effect of intraruminal infusion of potassium on the site of magnesium absorption within the digestive tract in sheep

1997 ◽  
Vol 129 (1) ◽  
pp. 99-105 ◽  
Author(s):  
D. E. DALLEY ◽  
P. ISHERWOOD ◽  
A. R. SYKES ◽  
A. B. ROBSON
Keyword(s):  
Digestive Tract ◽  
Solid Phase ◽  
Latin Square ◽  
Cerium Chloride ◽  
Faecal Excretion ◽  
Absorption Increase ◽  
High K ◽  
Before And After ◽  
Lincoln University ◽  
Female Sheep

Sixteen 2-year old female sheep were fitted with ruminal and duodenal cannulae at Johnstone Memorial Laboratory, Lincoln University during 1989–90. They were offered, at 2 hourly intervals, a pelleted concentrate diet (900 g/day) and chaffed lucerne hay (100 g/day). In a split-plot experiment they were infused, intraruminally and at four rates, with potassium (providing 16, 26, 36 or 46 g K/kg food DM/day) and magnesium (providing 1·3, 1·8, 2·3 or 3·1 g Mg/kg food DM/day) within a Latin square design and with the liquid and solid phase markers 51chromium EDTA and 141cerium chloride. Net absorption of Mg before and after the duodenum was estimated from dietary intake, duodenal flow and urinary and faecal excretion of Mg.Increasing K intake resulted in a decline in net absorption of Mg from the entire digestive tract, supporting data in the literature. Increasing K intake from 16 to 46 g/kg DM decreased urinary Mg excretion by between 0·14 and 0·30 g/day, the extent of which was independent of the level of Mg intake. At high K intake Mg absorption from the rumen was reduced, the amount absorbed ranging from 0·07 g Mg/day at intakes of 1·3 g Mg/day and 46 g K/kg DM/day to 0·66 g Mg/day at intakes of 3·1 g Mg/day and 16 g K/kg DM/day. However, at high K intake, and when Mg absorption from the rumen was reduced, net Mg absorption from sites distal to the rumen was increased to an extent which suggested compensatory absorption. Increase in K intake was associated with a consistent reduction in plasma Mg concentration which was independent of Mg intake. Increases in Mg intake resulted in increases in Mg absorption and plasma Mg concentration at all rates of K intake in direct proportion to rate of intake. The reduction in Mg absorption from the rumen at high K intake was associated with an increase (0·3 units) in pH of rumen digesta.

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