Uranium(VI) recovery from its leach liquor using zirconium molybdophosphate composite: kinetic,equilibrium and thermodynamic studies

Journal of Radioanalytical and Nuclear Chemistry - A zirconium molybdophosphate composite was designed for the selective recovery of uranium ions. The synthesized composite was well-characterized...     

A study of a newly synthesized ligand and its metal complexes in bulk and nano size and metal uptake efficiency

A newly synthesized ligand derived from 2-amino thiophenol and benzoic anhydride and its Co(II), Cd(II), La(III) (in bulk and nano size), and Gd(III) complexes was investigated and characterized. The maximum elimination capacity of the newly synthesized ligand was investigated towards the removal of Co(II), Cd(II), La(III), and Gd(III) ions from aqueous solutions. It was found that the ligand has the best removal ability for Cd(II) metal of 98.66% at a concentration of 0.03 mg/L.     

Fibrations et conjecture de Tate

Résumé

Nous décrivons le comportement du rang du groupe de Mordell-Weil de la variété de Picard de la fibre générique d’une fibration en termes de contributions locales données par des moyennes de traces de Frobenius agissant sur les fibres. Les énoncés fournissent une réinterpretation de la conjecture de Tate (pour les diviseurs) et généralisent des résultats antérieurs de Nagao, Rosen-Silverman et des auteurs.

Abstract. Fibrations and Tate's conjecture

We describe the behaviour of the rank of the Mordell-Weil group of the Picard variety of the generic fibre of a fibration in terms of local contributions given by averaging traces of Frobenius acting on the fibres. The results give a reinterpretation of Tate's conjecture (for divisors) and generalises previous results of Nagao, Rosen-Silverman and the authors.     

Synthesis, <Emphasis Type=Italic>Spectrofluorometric</Emphasis> Studies,Micellization and non Linear Optical Properties of Blue Emitting Quinoline (AMQC) Dye

Blue emitting 2-amino-4-(3, 4, 5-tri methoxyphenyl)-9-methoxy-5,6 dihydrobenzo[f]isoquinoline-1-carbonitrile (AMQC) dye was synthesized by one-pot multicomponent reactions (MCRs) of 3,4,5-trimethoxybenzaldehyd, malononitrile, 6-methoxy-1,2,3,4-tetrahydro-naphthalin-1-one and ammonium acetate. Results obtained from spectroscopic and elemental analysis of synthesized AMQC was in good agreement with their chemical structures. Fluorescence polarity study demonstrated that AMQC was sensitive to the polarity of the microenvironment provided by different solvents. In addition, spectroscopic and physicochemical parameters, including electronic absorption, excitation coefficient, stokes shift, oscillator strength, transition dipole moment and fluorescence quantum yield were investigated in order to explore the analytical potential of AMQC. Dye undergoes solubilization in different micelles and may be used as a quencher and a probe to determine the critical micelle concentration (CMC) of SDS and CTAB. Nonlinear optical parameters of AMQC dye shows relatively lower nonlinear refractive index and nonlinear absorption coefficient at the power levels. Variation of n₂ with concentration is linear in the concentration range used in the present study.     

Use of fullerene‐, octadecyl‐, and triaconthyl silica for solid phase extraction of tryptic peptides obtained from unmodified and in vitro glycated human serum albumin and fibrinogen

SPE plays a crucial role in bioanalytical research. In the present work a novel fullerene(C60)‐derivatised silica material is compared with octadecyl(C18) – and triaconthyl(C30)‐silicas regarding recoveries of peptides and sequence coverage of HSA and fibrinogen digests. C30‐ and C60(30 nm)‐SPE materials were found to be the two most prominent SPE materials. At low peptide concentrations C60‐material prepared from a silica gel with a pore size of 30 nm has proven to be the best material with regards to recoveries. By increasing the amount of loaded peptides recoveries decrease due to its relative low binding capacity in contrast to C30‐silica particles, showing no changes. The best sequence coverages of Aα‐ and Bβ‐chains of 20 pmol fibrinogen digest can also be achieved using these two SPE materials, C60 (30 nm) demonstrates an outstanding value of sequence coverage (62.15%) achieved for the γ‐chain. After nonenzymatic glycation the digests of fibrinogen and HSA were also separated. This makes the detection of a considerably higher number of glycated peptides possible compared to the unfractionated digests and the use of boronate affinity chromatography in the case of fibrinogen. For HSA, ten new sites of glycation at lysine and arginine residues have been explored. Using the detailed SPE/off‐line MALDI method the glycation sites on fibrinogen are first described in this paper.     

Physico-chemical characteristics of vernamycin-A antibiotic biosynthesis by streptomyces SP-AZ-SH-29

Seventy-five actinomycete isolates were isolated from different soil samples collected from different localities in Egypt. One of the actinomycete culture AZ-SH-29 from three cultures was found to produce a wide spectrum antimicrobial agent. The actinomycete isolate AZ-SH-29 matches with Streptomyces ramulosus in the morphological, physiological, and biochemical characters. Thus, it was given the suggested name Streptomyces ramulosus-AZ-SH-29. The parameters controlling the biosynthetic process of the antimicrobial agent formation including; different pH values, different temperatures, different incubation period, and different carbon and nitrogen sources, were fully investigated. The active metabolite was extracted using ethyl acetate (1:1, v/v) at pH 7.0. The separation of the active ingredient and its purification were performed using column chromatography (CC) technique. The physico-chemical characteristics of the purified antimicrobial agent have been investigated. This analysis indicates a suggested imperical formula of C₂₀H₂₅N₂O₅. The minimum inhibition concentrations “MICs” of the purified antibiotic and antiviral test were also determined. The purified antimicrobial agent was suggestive of being belonging to Depsipeptide (Mikamycin) group (Vernamycin-A antibiotic) produced by Streptomyces ramulosus, AZ-SH-29.     

Material-enhanced laser desorption/ionization (MELDI)—A new protein profiling tool utilizing specific carrier materials for time of flight mass spectrometric analysis

Over the past couple of years, proteomics pattern analysis has emerged as an effective method for the early diagnosis of diseases such as ovarian, breast, or prostate cancer, without identification of single biomarkers. MALDI-TOF MS, for example, offers a simple approach for fast and reliable protein profiling, especially by using carrier materials with various physical and chemical properties, in combination with a MALDI matrix. This approach is referred to as material-enhanced laser desorption/ionization (MELDI). In this paper, we report the development and application of derivatized carrier materials [cellulose, silica, poly(glycidyl methacrylate/divinylbenzene) (GMA/DVB) particles, and diamond powder] for fast and direct MALDI-TOF MS protein profiling. The applicability of MELDI for rapid protein profiling was evaluated with human serum samples. These carriers, having various hydrophobicities, resulted in characteristic mass fingerprints, even if all materials were derivatized with iminodiacetic acid (IDA) to yield an immobilized metal affinity chromatography (IMAC) functionality. Our study demonstrates that analyzing complex biological samples, such as human serum, by employing different MELDI carrier materials yielded type- and size-dependent performance variation.     

Direct, palladium-catalyzed, multicomponent synthesis of beta-lactams from imines, acid chloride, and carbon monoxide

A new palladium-catalyzed synthesis of 3-amido-substituted beta-lactams is reported. This process involves the one-pot coupling of four components, imines, carbon monoxide, and acid chloride, providing a flexible route to construct this class of heterocycle. The generation of beta-lactams with two different imines can also be accomplished, providing a method to assemble these products with independent control over five separate substituents.     

Synthesis of Quinoline/Phenanthroline Impregnated Sugarcane Bagasse for Recovering Uranium(VI) and Thorium(IV) from their Solutions

This present research aims to synthesize and investigate the adsorption potential of sugarcane bagasse (SCB) impregnated with 8 hydroxy quinolone 8-(HQ) and 1,10 phenethroline (phen) to prepare impregnated sugarcane bagasse (ISCB) for removal U^VI and Th^IV. The effects of the operating parameters, including pH of the solution, contact time, initial concentration, temperature, dose and interfering ions on the adsorption efficiency were investigated to identify an optimal condition. The characterization of SEM-EDX and FTIR analyses shows that ISCB has a porous structure and carbon-containing functional groups. The adsorption result revealed that ISCB removed 98 % for both U^VI and Th^IV. The result obtained fitted well for Langmuir isotherms model with 185.19 mg · g^–1 and 250 mg · g^–1 as theoretical capacity for U^VI and Th^IV respectively. The adsorption process followed the pseudo-second-order kinetic model. In conclusion, this study proved that ISCB has the potential to be used as an effective and low-cost adsorbent to remove U^VI and Th^IV. Finally we obtain products from thorium as ThO₂ and uranium as Na₂U₂O₇ from Abu Rushied leach liquor.     

Binary and ternary complexes involving copper(II), glycyl-dl-leucine and amino acids or amino acid esters: hydrolysis and equilibrium studies

Binary and ternary complex formation equilibria of copper(II) with glycyl-dl-leucine and amino acids or their esters were investigated potentiometrically at 25°C and a constant ionic strength. The kinetics of base hydrolysis of amino acid esters in their ternary complexes were monitored using the pH-stat method. The ester groups, with the exception of the histidine methyl ester, undergo rapid promoted hydrolysis. The rate and catalysis constants were evaluated from the experimental data.