Microextraction of metal ions based on solidification of a floating drop: Basics and recent updates

This review provides a comprehensive evaluation of solidified floating organic drop microextraction (SFODME) procedures for metal ions preconcentration and their contributions to green chemistry. In this article we focused on the modifications that have been performed in the recent years to improve this environmentally friendly procedure. Among the most important of these modifications are the inclusion of ultrasonic energy, vortex and air agitation to enhance the dispersion process. The article also discussed new challenges in the procedure by using more ecofriendly solvents as extractants such as ionic liquids, deep eutectic. and supramolecular solvents. The coupling of SFODME with solid phase extraction increases selectivity and efficiency of the preconcentration procedure.     

Effects of the dust size distribution on shock waves in dusty plasma

By using a Korteweg-deVries-Burgers(KdV-Burgers) equation and considering the dust size distribution, we have studied effects of the dust size distribution on the shock wave in dusty plasma. The dependence of characteristics of the shock wave on different dust size distributions has been given. It is found that the speed and amplitude of a shock wave considering the dust size distribution are larger than that of the dusty plasma with the averaged dust size. However, the width of a shock wave considering the dust size distribution is smaller than that of the dusty plasma with the averaged dust size.     

Can Anyon Statistics Explain High Temperature Superconductivity?

In this paper, we find a reasonable explanation of high temperature superconductivity phenomena using Anyon statistics.

     

Development and Validation of LC-ESI-MS/MS Method for the Determination of Alfuzosin in Human Plasma

Journal of Analytical Chemistry - A new liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) method has been developed and validated for alfuzosin quantification in...     

Macrocyclic Cr3+, Mn2+ and Fe3+ complexes of a mimic SOD moiety: Design,structural aspects,DFT, XRD,optical properties and biological activity

A novel SOD-like macrocycle “H₂DPD” and its trivalent chromium, iron and divalent manganese complexes have been isolated and characterized using the conventional tools. The macrocycle was prepared by 2:2 condensation of P-phenylenediamine with 5,5-dimethyl1,3-cyclohexanedione. IR and electronic spectral data suggested that H₂DPD coordinates to the metal ion as N₄ tetradentate donor with two Cl⁻ occupying the remaining two sites of the distorted octahedron. XRD spectrum of Cr³⁺ complex indicated that the complex crystallizes in a face-centered monoclinic structure with lattice parameters: a = 10.9380 Å; b = 12.4870 Å; c = 12.4600 Å, α = γ = 90° and β = 111.430 with space group P 1 21/c 1 (14). The energy gap (E_HOMO-E_LUMO), molecular electrostatic potential map (EPM) of title compounds, bond length, bond angle, as well as global and local reactivity were estimated using DFT method. The E_g values obtained from electronic spectra of Cr³⁺, Mn²⁺ and Fe³⁺ complexes were found to be 1.284, 1.220 and 1.138 eV, respectively which are in accordance with those evaluated by DFT revealing semiconductor nature. Also, the thermal degradation of all title compounds was carried out and the kinetic parameters were evaluated using Coats-Redfern and Horowitz-Metzger equations. Moreover, the compounds have screened for antibacterial as well as superoxide mimic activities. Cr³⁺ complex exhibited the most significant potent activity against all bacterial strains. With respect to SOD-like activity, the macrocycle showed the most remarkable SOD-like activity comparable to the standard drug, ascorbic acid.     

Synthesis,characterization, and biological investigation of new mixed-ligand complexes

A novel series of mixed-ligand complexes of 5,5′-{(1E,1E′)-1,4-phenelynebis(diazene-2,1-diyl)}bis(quinolin-8-ol) (H₂L₁) as a primary ligand and 4-aminoantipyrine(L₂) as a secondary ligand with Mn(II) ion were prepared using two general formulae: [Mn₂(H₂L₁)₂(L₂)₂X₄].4Cl (X = OH₂( 1 ), ONO₂⁻( 2 ), Cl=nil; OAc( 3 ), Cl = nil) and [Mn₂(H₂L₁)(L₂)₂(O₂SO₂)₂]( 4 ). Free ligands and their complexes were characterized. Electronic absorption spectra of the mixed-ligand complexes indicate a distorted octahedral geometry around the central metal ion, and the anions X⁻ are in the axial positions for all compounds. The ligands behave in a neutral bidentate manner, through nitrogen atoms and oxygen atoms of the carbonyl group (L₂), whereas H₂L₁ coordinated through nitrogen and OH groups as a neutral bidentate ligand. All complexes do not contain coordinated water molecules, but complex ( 1 ) contains four water molecules. The water molecules are removed in a single step. The complexes exhibited magnetic susceptibility corresponding to five unpaired electrons. The antimicrobial activity of the Mn(II) mixed-ligand complexes ( 1–4 ) against two gram-positive bacteria, three local gram-negative bacteria, and three fungi species was tested. Mn(II) mixed-ligand complex ( 2 ) exhibited significant antibacterial activity against Bacillus cereus, Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas sp. Mixed-ligand complex ( 2 ) exhibited a high potential cytotoxicity against the growth of human lung cancer cells.     

Single crystal X-ray of 1-[(1,2,4-triazole-4-yl)imino]diacetyl monoxime (L) as a novel triazole and the characterization and biological studies of its chelates of Co2+, Pd2+, and Fe3+

A novel and efficient synthesis of 1-[(1,2,4-triazole-4-yl)imino]diacetyl monoxime ( L ) is described. The advantages of this method are that it is inexpensive, the starting reactants are readily available, and it has good yield and short reaction times. The hull of the product was suggested by elemental analyses, spectral and single crystal X-ray. Novel Co ²⁺ , Pd²⁺, and Fe ³⁺ chelates derived from L were characterized by Fourier transform infrared spectroscopy, suggesting that L acts as bidentate via the two azomethine groups. Tetrahedral geometry for Fe³⁺ and Co²⁺ and square-planar geometry around the Pd²⁺ chelate were suggested depending on the spectral and magnetic data. The results of density functional theory were applied to illustrate the geometry of L towards the metal ions. Coats–Redfern and Horowitz–Metzger methods were applied to investigate the kinetic and thermodynamic parameters of the chelates. Cyclic voltammetry was carried out to study the stability of the Co²⁺ and Fe³⁺ chelates. L and its complexes were tested against three types of cancer cells, antibacterial and antifungal.     

Complex dynamics investigations of a mixed Bertrand duopoly game: synchronization and global analysis

Nonlinear Dynamics - In this paper, an economic competition between two firms that want to maximize the weighted-average social welfare and own profits is proposed. This kind of competition is...     

Oscillation criteria for higher‐order nonlinear dynamic equations with Laplacians and a deviating argument on time scales

In this paper, we study the n th‐order nonlinear dynamic equation with Laplacians and a deviating argument on an above‐unbounded time scale, where n ?2, New oscillation criteria are established for the cases when n is even and odd and when α  > γ ,α  = γ , and α  < γ , respectively, with α  = α ₁?α _{n  ? 1}. Copyright © 2017 John Wiley & Sons, Ltd.