... The compounds studied are malonic acid, phosphoric acid, glycine, acetohydroxamic acid, and potassium phosphonousformate in their various ...

Acetohydroxamic acid (AHA) has been proposed as a suitable reagent for the complexant-based, as opposed to reductive, stripping of plutonium and neptunium ions from the tributylphosphate solvent phase in advanced PUREX or UREX processes designed for future nuclear-fuel reprocessing. Stripping is achieved by the formation of strong ...

The efflux pump inhibitor phenyl-arginine-beta-naphthylamide (PAbetaN) was paired with iron chelators 2,2'-dipyridyl, acetohydroxamic acid, and EDTA to assess synergistic activities against Pseudomonas aeruginosa growth and biofilm formation. All of the tested iron chelators synergistically inhibited P. aeruginosa growth and biofilm ...

The structure and reactivity of a complex of zinc(II), water, acetic acid, and acetohydroxamic acid, in which one of the acids is deprotonated, is investigated by means of mass spectrometry, labeling studies, and density functional calculations to unravel the exceptional binding properties of hydroxamic ...

Acetohydroxamic acid is known to inhibit bacterial urease activity, thus, reducing urinary ammonia levels. A double-blind placebo-controlled clinical trial of acetohydroxamic acid was conducted at 12 Veterans Administration spinal cord injury units. A total of 210 male spinal cord injury patients with chronic ...

Aug 30, 2011 ... Recent abiotic kinetic experiments show distinct variations in the kinetics of iron dechelation from ferric acetohydroxamic acid (Fe-aha), ...

N-(2-Oxoalkyl)-2-chloroacetohydroxamic acids were obtained by acylation of 1,2-hydroxylamino ketones with chloroacetyl chloride. Their reaction with urotropin and sodium azide gives urotropinium salts and acetoxyhydroxamic acid azides. 1-Hydroxy-2-oxo-1,2,3,6-tetrahydropyrazines were obtained by treating N-(2-oxoalkyl)-2-chloroacetohydroxyamic ...

Aceto-hydroxamic acid (AHA) is used as a stripping agent In the UREX process. While extraction yields of uranium remain high upon addition of AHA, hexavalent plutonium and neptunium are rapidly reduced to the pentavalent state while the tetravalent species and removed from the product stream. However, under acidic conditions, ...

Acetohydroxamic acid has been evaluated as a urease inhibitor in male CAF-1 mice, utilizing collected 14CO2 from injected 14C-urea as the index of ureolysis. The log-dose response curve for inhibition during the first 2 hours after intraperitoneal adminis...

Three levels of acetohydroxamic acid (AHA) were administered into the rumen of two sheep. Each sheep received 90, 180 and 360 mg. of AHA per kg. of body weight each day for 5 days in addition to serving as his own control. The sheep were fed an 85% rougha...

We have identified potassium 2-nitroimidazole-1-acetohydroxamate (KIH-802) as a hypoxic cell radiosensitizer potentially superior to Miso. The water-soluble acetohydroxamates of 2-nitroimidazole (KIH-802; free acid 801) and 4-nitroimidazole (KIH-852) were designed, synthesized, and evaluated by in vitro and in vivo screening against ...

We describe novel acetohydroxamic acid derivatives with potent activity against cultured bloodstream-form Trypanosoma brucei and selectivity indices of >1000. These analogues were derived from conformationally constrained, lipophilic, spiro carbocyclic 2,6-diketopiperazine (2,6-DKP) scaffolds by attaching acetohydroxamic ...

We describe novel acetohydroxamic acid derivatives with potent activity against cultured bloodstream-form Trypanosoma brucei and selectivity indices of >1000. These analogues were derived from conformationally constrained, lipophilic, spiro carbocyclic 2,6-diketopiperazine (2,6-DKP) scaffolds by attaching acetohydroxamic ...

The kinetics of reduction of NpO22+ to NpO2+ by acetohydroxamic acid in 1 mol�L?1perchloric acid media at 10 and 22�C were studied. The reaction rate was monitored using stopped-flow and standard infrared spectroscopy. Under conditions such that acetohydroxamic acid was in excess relative ...

Reductive nitrosylation and complexation of ammonium pertechnetate by acetohydroxamic acid has been achieved in aqueous nitric and perchloric acid solutions. The kinetics of the reaction depend on the relative concentrations of the reaction components and are accelerated at higher temperatures. The reaction does not occur unless ...

Reductive nitrosylation and complexation of ammonium pertechnetate by acetohydroxamic acid has been achieved in aqueous nitric and perchloric acid solutions. The kinetics of the reaction depend on the relative concentrations of the reaction components and are accelerated at higher temperatures. The reaction does not occur unless ...

Reductive nitrosylation and complexation of ammonium pertechnetate by acetohydroxamic acid has been achieved in aqueous nitric and perchloric acid solutions. The kinetics of the reaction depend on the relative concentrations of the reaction components and are accelerated at higher temperatures. The reaction does not occur unless ...

The Uranium Extraction (UREX) process is being developed for the spent oxide fuel from light water reactors as part of the Accelerator Transmutation of Waste Project. The UREX process is similar to the Plutonium and Uranium Extraction (PUREX) process in that it involves solvent extraction based on a tributyl phosphate extractant. To assure that actinide reduction and complexation are effective, ...

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The complexation of neptunium (IV) with selected inorganic and organic ligands was studied as part of an investigation to establish key subsurface interactions between neptunium and biological systems. The prevalence of reducing environments in most subsurface migation scenarios, which are in many cases induced by biological activity, has increased the role and importance of Np(IV) as a key ...

The stability constant of the Pu(IV)-acetohydroxamic acid complex Pu(AHA)3+ at 1 M ionic strength (pH = 0) has been investigated by method of solvent extraction. Di(2-ethylhexyl) phosphoric acid (HDEHP) was used to extract Pu(IV) from perchloric and nitric acid media at various AHA concentrations. Distribution ...

The transmutation of transuranic actinides and long-lived fission products in spent commercial nuclear reactor fuel has been proposed as one element of the Advanced Accelerator Applications Program. Preparation of targets for irradiation in an accelerator-driven subcritical reactor would involve dissolution of the fuel and separation of uranium, technetium, and iodine from the transuranic ...

Urease activity of tobacco XD cells (1U cells) had undergone a 4-fold increase (4U cells) during a year of growth on urea. A clone of 4U cells gave rise to 12U cells during another year of growth on urea. The doubling time of 12U cells on urea is 2.2 days, compared to about 4 days for 1U cells, while 1U and 12U cells double in 2 days on nitrate. Acetohydroxamic ...

The PUREX extraction process is used worldwide to recover uranium and plutonium from dissolved spent nuclear fuel using the tributylphosphate-nitric acid extraction system. In the recent decade, significant research progress was achieved with the aim to modify this system by addition of a salt-free agent to optimize stripping of plutonium from the tributylphosphate (TBP) ...

The formation of N-arylacetohydroxamic acid derivatives from m-nitrosobenzyl alcohol (MBNO) and a nitroso derivative of chloramphenicol, 2,2-dichloro-N-[2-hydroxy-1-(hydroxymethyl)-2-(4-nitrosophenyl) ethyl]acetamide, in the presence of pyruvate was investigated with rat isolated cells (heart, kidney, liver, small intestine, lung, bone marrow and ...

The protonated forms of the basic ligand 1,4,7,13,16,19-hexaaza-10,22-dioxacyclotetracosane or 24ane-N602 (O-BISDIEN) recognize certain anions. The compounds studied are malonic acid, phosphoric acid, glycine, acetohydroxamic acid, and potassium phosphono...

Acyltransferase activity of amidase from Bacillus sp. APB-6 was enhanced (24 U) by multiple feedings of N-methylacetamide (70 mM) into the production medium. Hyperinduced whole resting cells of Bacillus sp. APB-6 corresponding to 4 g/L (dry cell weight), when treated with 10mM DTT (dithiothreitol) resulted in 93% molar conversion of acetamide (300 mM) to acetohydroxamic ...

The pharmacological effects of hydroxamate derivatives have been attributed not only to metal chelation or enzyme inhibition but also to their ability to serve as nitroxyl (HNO/NO(-)) and nitric oxide (NO) donors. However, the mechanism underlying the formation of these reactive nitrogen species is not clear and requires further elucidation. In the present study, one-electron ...

The inhibition by phosphocitrate of struvite crystal formation and growth has been examined in the present study. Crystal growth in a gel matrix was controlled by phosphocitrate in a dose-dependent manner. The effects of inhibition were followed using scanning electron microscopy, optical microscopy, and single crystal X-ray analysis. The presence of phosphocitrate induced ...

A spent fuel reprocessing method contacts an aqueous solution containing Technetium(V) and uranyl with an acidic solution comprising hydroxylamine hydrochloride or acetohydroxamic acid to reduce Tc(V) to Tc(II, and then extracts the uranyl with an organic phase, leaving technetium(II) in aqueous solution.

The decarbonylation of erythro- and threo-2,3-diphenylbutanoyl chloride with chlorotris(triphenylphosphine)rhodium(I) gave exclusively trans- and cis- methylstilbene, respectively. These results are best explained either by an acyl- - alkyl rearrangement with retention and a cis BETA -hydride elimination, or a concented cis elimination. The rates of the decarbonylation of dichioro(3- ...

A summary is given of the research into the mechanisms of radiation damage in molecules of biological interest. Areas studied are the mechanism controlling deamination in irradiated amino acids, ESR spectra of the irradiated L and DL isomers of the same amino acid, hydrogen atom diffusion in the decay of radical pairs in urea-type molecules, optical ...

The UREX process is being developed to process irradiated power reactor elements by dissolution in nitric acid and solvent extraction by a variation of the PUREX process.1 Rather than recovering both U and Pu, as in Purex, only U will be recovered by solvent extraction, hence the name ''UREX.'' A complexing agent, ...

A process is described for the decontamination of solid surfaces contaminated with radioactive or heavy metal species using a solution based on one or more non-persistent complexing agents, or for the chemical cleaning of steam generator sludge using such a solution, or for removing radioactive or heavy metal species from a solution using a combination of a one or more non-persistent complexing ...

Gellan based floating beads of acetohydroxamic acid (AHA) were prepared by the ionotropic gellation method to achieve controlled and sustained drug release for treatment of Helicobacter pylori infection. The prepared beads were evaluated for diameter, surface morphology and encapsulation efficiency. Formulation parameters like concentrations of gellan, ...

Nitro-compounds containing an acetylated acetohydroxamic acid side chain inthe N-1 position of a 5-membered ring nitrogen heterocycle have been synthesized. These compounds, which can generate isocyanates via a Lossen rearrangement, were evaluated in order to test the hypothesis that they may be effective radiation and chemosensitizing agents by nature of ...

Acetohydroxamic acid (AHA) is a novel complexant for recycle of nuclear-fuel materials. It can be used in ordinary centrifugal extractors, eliminating the need for electro-redox equipment or complex maintenance requirements in a remotely maintained hot cell. In this work, the effect of AHA on Pu(IV) distribution ratios in 30% TBP system was quantified, ...

Acetohydroxamic acid (AHA) has been identified as a potential agent for the treatment of infection-induced staghorn renal calculi in patients. The pharmacokinetics and disposition of /sup 14/C-acetamide have been evaluated in rats following iv and oral administration. The results of these experiments suggest that, following oral administration to rats, AHA ...

Bacteria, algae and plants produce metal-specific chelators to capture required nutrient or toxic trace metals. Biological systems are thought to be very efficient, honed by evolutionary forces over time. Understanding the approaches used by living organisms to select for specific metals in the environment may lead to design of cheaper and more effective approaches for metal recovery and ...

Equilibrium results based on pH potentiometric, spectrophotometric and (1)H NMR measurements for the complexes of Fe(III), Al(III) and Mo(VI) with 2,3-dihydroxy-phenylalanine-hydroxamic acid (Dopaha) as well as for binary model systems Fe(III)-, Al(III)-, Mo(VI)-acetohydroxamic acid (Aha), -alpha-alaninehydroxamic ...

The concentration of molybdenum(VI) in dissolved irradiated nuclear fuel is comparable with the concentrations of Tc, Am and Np. Therefore it is of big interest to understand its behavior under conditions related to the UREX/TRUEX process. The effect of the poly-speciation of molybdenum in aqueous solution on its extraction by neutral solvents TBP and CMPO/TBP was studied. Extraction yields of ...

Electronic structures of the binary complexes of acetohydroxamic acid (AHA) and hydrogen halides, HX (X = F, Cl, Br) have been investigated using the second order perturbation theory. In the lowest energy structure of AHA...HF complex, hydrogen fluoride acts as a proton-donor with carbonyl oxygen and simultaneously as a proton-acceptor with the hydroxyl ...

Theoretical (ab initio calculations) and experimental (NMR, spectrophotometric, and potentiometric measurements) investigations of the isomers of acetohydroxamic acid (AHA) and their deprotonation processes have been performed. Calculations with the Gaussian 98 package, refined at the MP2(FC)/AUG-cc-pVDZ level considering the molecule isolated, indicate ...

... Title : INVESTIGATION OF COMPLEX FORMATION OF HYDROXYSTEARIC ACID WITH BORIC ACID BY INFRARED ABSORPTION SPECTRA,. ...

... Title : Controlled Formation of Carboxylic Acid Groups at Polyphosphazene Surfaces: Oxidative and Hydrolytic Routes,. ...

Urease has been suggested to be essential for colonization and pathogenesis of Helicobacter pylori infection. In the present study, we evaluated the effects of urease inhibitors [acetohydroxamic acid (AHA) and flurofamide (FFA)] on H. pylori-induced gastritis in Mongolian gerbils. Animals were orally inoculated with H. pylori, and given urease inhibitors ...

The deprotonation and iron complexation of the hydroxamate siderophore, desferrioxamine B (desB), and a model hydroxamate ligand, acetohydroxamic acid (aHa), were studied using infrared, resonance Raman and UV-vis spectroscopy. The experimental spectra were interpreted by a comparison with DFT calculated spectra of aHa (partly hydrated) and desB (reactive ...

To support either the continued operations of current reprocessing plants or the development of future fuel processing using hydrometallurgical processes, such as Advanced Purex or UREX type flowsheets, the accurate simulation of Purex solvent extraction is required. In recent years we have developed advanced process modeling capabilities that utilize modern software platforms such as Aspen Custom ...

The extractability of various Pu and Np species into tri-n-butyl phosphate (TBP) was investigated. The concentration effects of aceto-hydroxamic acid, nitric acid and nitrate on the distribution ratio of U, Pu and Np were investigated. The considerable ability of AHA to form complexes with the studied elements even under strong ...

... treatment of the polyamic acid that had been ... of the pyromellitic acid and a ... Descriptors : (*CARBOXYLIC ACIDS, *POLYMERIZATION), (*INFRARED ...

Cartoon of Acid Rain Formation. Figure 1: Acid Rain Formation. This image shows the process by which aerosols contribute to the formation of acid rain. ...

The permeability of a siliceous formation is increased by injecting in sequence, a fluoboric acid solution followed by a mud acid (Hcl/Hf) solution. The method is particularly advantageous in formations which have a tendency to plug initially upon contact with mud acid or with Hcl commonly used ...

INTRODUCTION: Urease is the enzyme that catalyzes the hydrolysis of urea, which is involved in serious infections caused by Helicobacter pylori in the gastric tract, as well as Proteus and related species in the urinary tract. The necessity to treat such infections has stimulated intensive studies on various groups of urease inhibitors. AREAS COVERED: Patent literature on urease inhibitors with ...

A chlorinated cobalt dicarbollide(CCD)/polyethylene glycol (PEG) based solvent extraction process is being developed for the separation of Cs and Sr from leached spent light water reactor (LWR) fuel as part of the Advanced Fuel Cycle Initiative (AFCI). The separation of Cs and Sr would significantly reduce the heat generation of spent nuclear fuel requiring geologic disposal. A solvent composition ...

... all form simple heteropoly acid species, and ... a mixture of simple heteropoly acids. ... COMPLEX COMPOUNDS), (*INORGANIC ACIDS, COMPLEX ...

A method of treating a subterranean sandstone formation with an aqueous acid solution containing hydrofluoric acid is described. The reaction rate of the acid with the formation is retarded and substantial penetration of the formation with active acid ...