Determination of trace elements of Egyptian crops by neutron activation analysis

Multielemental neutron activation analysis was used for the determination of Al, As, Au, Br, Ca, Cd, Co, Cr, Cu, Fe, La, Mn, Mo, Sb, Se, W and Zn in African tea, and lady's fingers (Malvaceae Family), ginger (Zingiperaceae Family), canella bark (Laureceae Family), black pepper (Piperaceae Family), cucumber seeds and vegetable marrow seeds (Cucurbitaceae Family), tomatos seed (Solanaceae Family), safflower seeds (Compositae Family), jew's mallow seeds (Tiliaceae Family) and sesame (Pedaliaceae Family). Trace elements determination was made to the analysis of destructive (using super pure nitric acid and adsorbing the metal-APDC and metal-Dz complexes on activated charcoal) and nondestructive (dry seeds) samples. The method is simple, precise and sensitive for the determination of microamounts of the elements (ppm to ppb).     

Mixed ligand complexes of benzimidazole and pyrimidine hydroxy azo dyes with some transition metals and glycine, dl-alanine or dl-leucine

The overall formation constants of 1:1:1 ternary complexes of Cu(II), Zn(II), Cd(11) with glycine, dl-alanine or dl-leucine as primary ligands and o-hydroxyphenylyazo derivatives of 2-cyanomethyl benzimidazole (ABI) and barbituric acid (ABA) as secondary ligands have been investigated potentiometrically in 40% (v/v) EtOH. Formation constants of binary systems were also determined under the same experimental conditions (37 degrees C and mu=0.15 mol dm(-3)). The stability of ternary complexes have been quantitatively compared with those of the corresponding binary complexes in terms of the parameters DeltalogK, logX and logX'. The data were interpreted on the basis of statistical considerations and the nature of complexes. The concentration distribution of various species formed in solution was evaluated. The Cu(II) complexes have been synthesized and the coordination sites of the ligands were characterized by means of IR spectroscopy.     

Solvent and pH Effects on the Electronic Spectra of Some Azo Benzimidazoles

The spectral behaviour of some new azobenzimidazoles in pure and mixed organic solvents and buffer solutions of varying pH have been studied. The observed bands are assigned to the possible electronic transition. The shoulder appearing in the visible region in the spectra of P‐NO₂ derivatives is ascribed to the existence of these compounds in azo‐hydrazone tautomeric equilibrium. The possibility of the formation of an intermolecular H‐bonded solvated complex between the molecules of p‐NO₂ derivatives and the proton acceptor solvents DMSO and DMF were studied. The pK values of these compounds were determined and explained on the basis of the relative contribution of acidic and basic character of respective species.     

Structure and complexation equilibria of metal(II) ions with 4-arylazopyrazoles

Summary Octahedral mononuclear and tetrahedral binuclear 4-arylazo-3,5-diaminopyrazole complexes of copper(II), nickel(II), cobalt(II) and manganese(II) have been prepared and characterized by elemental analysis, conductivity measurements and by i.r., ¹H n.m.r. and electronic spectroscopy. Complexation equilibria, stoichiometry and stability constants were measured in 40% (v/v) EtOH-H₂O medium and I = 0.1 mol dm ⁻³ NaClO₄. In mild acidic media, the ligands behave as neutral NN′ bidentates, while in alkaline media they act as N²N₂′ tetradentate ligands.     

Intrinsic equations for a generalized relaxed elastic line on an oriented surface in the galilean space

In this article, we derive the intrinsic equations for a generalized relaxed elastic line on an oriented surface in the Galilean 3-dimensional space G₃. These equations will give direct and more geometric approach to questions concerning about generalized relaxed elastic lines on an oriented surface in G₃.     

Lentivirus-mediated transgene delivery to the hippocampus reveals sub-field specific differences in expression

Background  

In the adult hippocampus, the granule cell layer of the dentate gyrus is a heterogeneous structure formed by neurons of different ages, morphologies and electrophysiological properties. Retroviral vectors have been extensively used to transduce cells of the granule cell layer and study their inherent properties in an intact brain environment. In addition, lentivirus-based vectors have been used to deliver transgenes to replicative and non-replicative cells as well, such as post mitotic neurons of the CNS. However, only few studies have been dedicated to address the applicability of these widespread used vectors to hippocampal cells in vivo. Therefore, the aim of this study was to extensively characterize the cell types that are effectively transduced in vivo by VSVg-pseudotyped lentivirus-based vectors in the hippocampus dentate gyrus.