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Accumulation of toxic metals in liver, a rich natural source of essential elements, can present health risks to regular consumers of liver. A total of 35 fresh liver samples of cow, sheep, goat, pig, grass-cutter (Thryonomys swinderianus), giant rat (Cricetomys gambianus), red deer (Cervus elaphus), chicken and antelope (Antilocapra americana) were obtained(More)
The oxo complexes of group VII B are of great interest for their potential toward epoxidation and dihydroxylation. In this work, the mechanisms of oxidation of ethylene by rhenium-oxo complexes of the type LReO3 (L = O(-), Cl, CH3, OCH3, Cp, NPH3) have been explored at the B3LYP/LACVP* level of theory. The activation barriers and reaction energies for the(More)
BACKGROUND 1,3-Dipolar [3 + 2]-cycloaddition of nitrones to the carbon-carbon double bonds of methylenecyclopropanes yields a mixture of regioisomeric 4- and 5-isoxazolidines. The mechanisms of the reactions of N,C,C-trisubstituted nitrones with ring acceptor substituted dimethyl methylenecyclopropanes-1,2-dicarboxylate and aryl methylidene(More)
The mechanistic aspects of ethylene addition to MO2(CH2)(CH3) (M=Co, Rh, Ir) have been investigated with a Hartree-Fock/DFT hybrid functional at the MO6/LACVP* and B3LYP/LACVP* levels of theory to elucidate the reaction pathways on the singlet, doublet and triplet potential energy surfaces (PES). In the reaction of the IrO2CH2CH3 complex with ethylene, [3 +(More)
The mechanisms of oxidation of ethylene by manganese-oxo complexes of the type MnO3L (L = O(-), Cl, CH3, OCH3, Cp, NPH3) have been explored on the singlet, doublet, triplet and quartet potential energy surfaces at the B3LYP/LACVP* level of theory and the results discussed and compared with those of the technetium and rhenium oxo complexes we reported(More)
The mechanistic pathways for the formation of epoxide, 1,2-dichloroethane, 1,2-chlorohydrin, acetaldehyde, and vinyl alcohol precursors in the oxidation of ethylene by chromyl chloride has been studied using hybrid density functional theory at the B3LYP/LACVP* level of theory. The formation of the epoxide precursor (Cl(2)(O)Cr-OC(2)H(4)) was found to take(More)
The periselectivity and chemoselectivity of the addition of transition metal oxides of the type ReO3L (L = Cl, CH3, OCH3 and Cp) to ethenone have been explored at the MO6 and B3LYP/LACVP* levels of theory. The activation barriers and reaction energies for the stepwise and concerted addition pathways involving multiple spin states have been computed. In the(More)
We have used spin polarized density functional theory calculations to perform extensive mechanistic studies of CO2 dissociation into CO and O on the clean Fe(100), (110) and (111) surfaces and on the same surfaces coated by a monolayer of nickel. CO2 chemisorbs on all three bare facets and binds more strongly to the stepped (111) surface than on the open(More)
The potential energy surfaces of the reactions of Cl(4)MCH(2) (M = Cr, Mo, W, Ru, Re) with ethylene, models of potential chain-carrying catalysts and olefins respectively in the transition metal-catalyzed olefin metathesis reaction, have been explored using density functional theory at the B3LYP/LACVP* level of theory. In Cl(4)MCH(2) (M = Cr, Ru), the(More)
BACKGROUND Historical proven wood species have no reported adverse health effect associated with its past use. Different historical proven species have traditionally been used to manufacture different wooden food contact items. This study uses survey questionnaires to assess suppliers', manufacturers', retailers' and consumers' (end-users') preferences for(More)