Use of some Inorganic and Organic Compounds as Decontaminants for Cobalt-60 and Caesium-134 by Clover Plant Grown on Inshas Sandy Soil

Outdoor lysimeter experiments were carried out to elucidate the effect of 4 inorganic and 3 organic salts on ⁶⁰Co and ¹³⁴Cs uptake and dry matter yield of three cuts of clover in the soils of Inshas. A new concept was proposed for assessing the difference in capacity of soil to supply radionuclides to plants as affected by applied inorganic or organic compounds. A relation of plant tissue radionuclide content with time can be expressed in an exponential equation with corresponding regression coefficients. When the same plant species is grown on the same soil differing only in the applied compounds (e.g. Fe-EDDHA, Fe-DTPA, Fe-OAC, Fe(COO)₂, Al(OH)₃, Ca(H₂PO₄)₂, Fe₂O₃) the derived equation will change. Differences of either Co or Cs accumulation with time between control and any other treatment were evaluated. The data also show that Fe-DTPA is preferred for ⁶⁰Co as enhancing compound for plant uptake (for decontamination use), compared with other applied salts, on the other hand, any tested salts did not significantly effect ¹³⁴Cs taken by clover. It was also found that more than 70% of the total cobalt uptake was accumulated in the roots which indicate that Co is less mobile in plants than Cs.     

Solid state radiolysis of non-proteinaceous amino acids in vacuum: astrochemical implications

The analysis of the amino acids present in Murchison meteorite and in other carbonaceous chondrites has revealed the presence of 66 different amino acids. Only eight of these 66 amino acids are proteinaceous amino acids used by the present terrestrial biochemistry in protein synthesis, the other 58 amino acids are somewhat “rare” or unusual or even “unknown” for the current terrestrial biochemistry. For this reason in the present work a series of “uncommon” non-proteinaceous amino acids, namely, l-2-aminobutyric acid, R(?)-2-aminobutyric acid, 2-aminoisobutyric acid (or α-aminoisobutyric acid), l-norleucine, l-norvaline, l-β-leucine, l-β-homoalanine, l-β-homoglutamic acid, S(?)-α-methylvaline and dl-3-aminoisobutyric acid were radiolyzed in vacuum at 3.2 MGy a dose equivalent to that emitted in 1.05 × 10⁹ years from the radionuclide decay in the bulk of asteroids or comets. The residual amount of each amino acid under study remained after radiolysis was determined by differential scanning calorimetry in comparison to pristine samples. For optically active amino acids, the residual amount of each amino acid remained after radiolysis was also determined by optical rotatory dispersion spectroscopy and by polarimetry. With these analytical techniques it was possible to measure also the degree of radioracemization undergone by each amino acid after radiolysis. It was found that the non-proteinaceous amino acids in general do not show a higher radiation and radioracemization resistance in comparison to the common 20 proteinaceous amino acids studied previously. The unique exception is represented by α-aminoisobutyric acid which shows an extraordinary resistance to radiolysis since 96.6 % is recovered unchanged after 3.2 MGy. Curiously α-aminoisobutyric acid is the most abundant amino acid found in carbonaceous chondrites. In Murchison meteorite α-aminoisobutyric acid represents more than 20 % of the total 66 amino acids found in this meteorite.     

Synthesis, Characterization, and Antimicrobial Activity of Poly(acrylonitrile-co-methyl methacrylate) with Silver Nanoparticles

Nanotechnology is expected to open some new aspects to fight and prevent diseases using atomic-scale tailoring of materials. The main aim of this study is to biosynthesize silver nanoparticles (AgNPs) using Trichoderma viride (HQ438699); the metabolite of this fungus will help either in reduction of the silver nitrate-adding active materials which will be loaded on the surface of the produced AgNPs. Poly(acrylonitrile-co-methyl methacrylate) copolymer (poly (AN-co-MMA)) was grafted with the prepared AgNPs. The poly(AN-co-MMA)/AgNPs were examined against ten different pathogenic bacterial strains, and the result was compared with another four different generic antibiotics. The produced poly(AN-co-MMA)/AgNPs showed high antibacterial activity compared with the four standard antibiotics. Moreover, the grafting of these AgNPs into the copolymer has potential application in the biomedical field.     

Silent, fluorescent labeling of native neuronal receptors

We have developed a minimally-perturbing strategy that enables labeling and subcellular visualization of endogenous dendritic receptors on live, wild-type neurons. Specifically, calcium-permeable non-NMDA glutamate receptors expressed in hippocampal neurons can be targeted with this novel synthetic tri-functional molecule. This ligand-directed probe was targeted towards AMPA receptors and bears an electrophilic group for covalent bond formation with an amino acid side chain on the extracellular side of the ion channel. This molecule was designed in such a way that the use-dependent, polyamine-based ligand accumulates the chemically-reactive group at the extracellular side of these polyamine-sensitive receptors, thereby allowing covalent bond formation between an electrophilic moiety on the nanoprobe and a nucleophilic amino acid sidechain on the receptor. Bioconjugation of this molecule results in a stable covalent bond between the nanoprobe and the target receptor. Subsequent photolysis of a portion of the nanoprobe may then be employed to effect ligand release allowing the receptor to re-enter the non-liganded state, all the while retaining the fluorescent beacon for visualization. This technology allows for rapid fluorescent labeling of native polyamine-sensitive receptors and further advances the field of fluorescent labeling of native biological molecules.     

Microwave-assisted synthesis and heterocyclic functionalization of chromenopyridines on calixarene scaffold

A three-component one-pot condensation reaction of chroman-4-one with ethyl 2-cyanoacetate and various aldehydes in the presence of ammonium acetate afforded a series of 2-oxo-4-phenyl-1,5-dihydro-2H-chromeno[4,3-b]pyridine-3-carbonitrile. These heterocycles have been converted to chloropyridine derivatives and appended to macrocyclic calix[4]arene scaffold through aromatic nucleophilic substitution under microwave irradiation. In this study, the microwave-assisted functionalization of the lower rim of calix[4]arene has been considered the only appropriate tool because the conventional heating did not lead to any new product after 72 hours of heating under thermal condition.     

SYNTHESIS AND APPLICATION OF SOME NEW 5-SULPHONYL-N-HETEROCYCLO-8-HYDROXYQUINOLINE DERIVATIVES AS POTENTIAL DRUGS

Abstract

Some new sulphonyl-N-heterocyclo-8-hydroxy quinolines have been synthesised by the reaction of 8-hydroxyquinoline-5-sulphonyl hydrazide with different active methylene compounds. The pyrazole, pyrazoline, pyrazolidine and pyridazine derivatives were reacted with some metal cations to give the corresponding chelates. All synthesized compounds have been screened in vitro for their biological activities.     

Selective preconcentration of uranyl ion by silica gel phases modified with chelating compounds as inorganic polymeric ion exchangers.

Four chemically modified chelating silica gel phases (I - IV) with ion exchange groups were tested for their potential capability to selectively bind, extract and preconcentrate uranyl ions (UO(2)(2+)) from different aqueous solutions as well as ore samples. Factors affecting such determination processes were studied and optimized. These included the pH of the contact solution, the mass of the silica gel phase extractant, the stirring time during the application of a static technique and the eluent concentration for desorption of the surface-bound uranyl ion and interfering anions and cations. All these factors were evaluated on the basis of determinations of the distribution coefficient value (K(d)) and the percent recovery (R%). Percent recovery values of 91% for silica phase (II) and 93% for silica phase (IV) were identified in the optimum conditions. The proposed preconcentration method was further applied to uranium ore samples as well as granite samples. The determined percentage and ppm values are in good agreement with the standard assigned ones. The structure of the synthesized silica gel phases (I - IV) and their uranyl bound complexes were identified and characterized by means of infrared analysis, thermal analysis (TGA) and potentiometric titration.     

2‐Arylhydrazono‐3‐oxopropanals in heterocyclic synthesis: Synthesis of arylazopyrazole,arylazoisoxazole and dialkylpyridazine‐5,6‐dicarboxylate derivatives. New one‐step synthesis of arylazopyrimidines

A novel synthesis of arylpyrazole, isoxazole, dialkyl 1,6‐dihydropyridazine 5,6‐dicarboxylate derivatives and a new one‐step synthesis of azolopyrimidines under microwave‐assisted conditions are reported.     

Tanh Jacobi spectral collocation method for the numerical simulation of nonlinear Schrödinger equations on unbounded domain

We present a class of orthogonal functions on infinite domain based on Jacobi polynomials. These functions are generated by applying a tanh transformation to Jacobi polynomials. We construct interpolation and projection error estimates using weighted pseudo-derivatives tailored to the involved mapping. Then, using the nodes of the newly introduced tanh Jacobi functions, we develop an efficient spectral tanh Jacobi collocation method for the numerical simulation of nonlinear Schrödinger equations on the infinite domain without using artificial boundary conditions. The applicability and accuracy of the solution method are demonstrated by two numerical examples for solving the nonlinear Schrödinger equation and the nonlinear Ginzburg–Landau equation.