MCM/ZrO2 nanoparticles modified electrode for simultaneous and selective voltammetric determination of epinephrine and acetaminophen

A novel MCM/ZrO₂ nanoparticles modified carbon paste electrode (MZ-CPE) was fabricated and used to study the electro oxidation of epinephrine (EP) and acetaminophen (AC) and their mixtures by electrochemical methods. The modified electrode showed electrocatalytic activity toward EP and AC oxidation with a decrease of the overpotential by 173 mV to a less positive potential for EP at the surface of the MZ-CPE and an increase in peak current at pH 7.0. Differential pulse voltammetry peak currents of EP and AC increased linearly with their concentrations in the ranges of 1.0 × 10^?6–2.5 × 10^?3 and 1.0 × 10^?6–2.0 × 10^?3 M, respectively, and the detection limits for EP and AC were 5.0 × 10^?7 and 4.5 × 10^?7 M, respectively.     

‘Click Synthesis’ of 1H‐1,2,3‐Triazolyl‐Based Oxiconazole (=(1Z)‐1‐(2,4‐Dichlorophenyl)‐2‐(1H‐imidazol‐1‐yl)ethanone O‐[(2,4‐Dichlorophenyl)methyl]oxime) Analogs

The ‘click synthesis’ of some oxiconazole analogs 5a – 5v having 1H‐1,2,3‐triazolyl residues by Huisgen cycloaddition was achieved in four steps (Scheme 1). Oximation of phenacyl chloride ( 1 ) followed by azidation of 2‐chloro‐1‐phenylethanone oxime ( 2 ) provided azido ketoxime 3 . The CuI‐catalyzed Huisgen cycloaddition of 3 with terminal alkynes gave the 4‐substituted (at the triazole) 2‐(1H‐1,2,3‐triazol‐1‐yl)‐1‐phenylethanone oximes 4a – 4i . The O‐alkylation of 4a – 4i with various alkyl halides resulted in the formation of the target molecules 5a – 5v in good yields.     

A Two Phase Free Boundary Problem Related to Quadrature Domains

In this paper we introduce a two phase version of the well-known Quadrature Domain theory, which is a generalized (sub)mean value property for (sub)harmonic functions. In concrete terms, and after reformulation into its PDE version the problem boils down to finding solution to

Capability of Crossed Modules of Lie Algebras

In this paper, we introduce the concept of capability for crossed modules of Lie algebras, which is a generalization of capability in Lie algebras and groups. By using a special central ideal of a crossed module, we give a sufficient condition for the capability of a crossed module of Lie algebras. Also, we will extend the five-term exact sequence on homology of crossed modules of Lie algebras one term further and study the connection between the capability of crossed modules and this sequence. Finally, we study the relation between the capability and the center of a cover of a crossed module.     

A new infeasible interior-point method based on Darvay’s technique for symmetric optimization

We present a full Nesterov and Todd step primal-dual infeasible interior-point algorithm for symmetric optimization based on Darvay’s technique by using Euclidean Jordan algebras. The search directions are obtained by an equivalent algebraic transformation of the centering equation. The algorithm decreases the duality gap and the feasibility residuals at the same rate. During this algorithm we construct strictly feasible iterates for a sequence of perturbations of the given problem and its dual problem. Each main iteration of the algorithm consists of a feasibility step and some centering steps. The starting point in the first iteration of the algorithm depends on a positive number ξ and it is strictly feasible for a perturbed pair. The feasibility steps find strictly feasible iterates for the next perturbed pair. By using centering steps for the new perturbed pair, we obtain strictly feasible iterates close to the central path of the new perturbed pair. The algorithm finds an ?-optimal solution or detects infeasibility of the given problem. Moreover, we derive the currently best known iteration bound for infeasible interior-point methods.     

Carbon‐iodide bond activation by cyclometalated Pt (II) complexes bearing tricyclohexylphosphine ligand: A comparative kinetic study and theoretical elucidation

Cyclometalated Pt (II) complexes [PtMe(C^N)(L)], in which C^N = deprotonated 2,2′‐bipyridine N‐oxide (Obpy), 1 , deprotonated 2‐phenylpyridine (ppy), 2 , deprotonated benzo [h] quinolone (bzq), 3 , and L = tricyclohexylphosphine (PCy₃) were prepared and fully characterized. By treatment of 1–3 with excess MeI, the thermodynamically favored Pt (IV) complexes cis‐[PtMe₂I(C^N)(PCy₃)] (C^N = Obpy, 1a ; ppy, 2a ; and bzq, 3a ) were obtained as the major products in which the incoming methyl and iodine groups adopted cis positions relative to each other. All the complexes were characterized by means of NMR spectroscopy while the absolute configuration of 1a was further determined by X‐ray crystal structure analysis. The reaction of methyl iodide with 1–3 were kinetically explored using UV–vis spectroscopy. On the basis of the kinetic data together with the time‐resolved NMR investigation, it was established that the oxidative addition reaction occurred through the classical S_N2 attack of Pt (II) center on the MeI reagent. Moreover, comparative kinetic studies demonstrated that the electronic and steric nature of either the cyclometalating ligands or the phosphine ligand influence the rate of reaction. Surprisingly, by extending the oxidative addition reaction time, very stable iodine‐bridged Pt (IV)‐Pt (IV) complexes [Pt₂Me₄(C^N)₂(μ‐I)₂] (C^N = Obpy, 1b ; ppy, 2b ; and bzq, 3b ) were obtained and isolated. In order to find a reasonable explanation for the observation, a DFT (density functional theory) computational analysis was undertaken and it was found that the results were consistent with the experimental findings.     

Analyticity of free boundary in an optimal harvesting problem

Letters in Mathematical Physics - This note revisits an optimisation problem pertaining to the optimal harvesting of a marine species. The existence of solutions and the corresponding optimal...     

Copper-doped silica cuprous sulfate (CDSCS) as a highly efficient and new heterogeneous nano catalyst for [3+2] Huisgen cycloaddition

The synthesis and characterization of copper-doped silica cuprous sulfate (CDSCS) as a new and efficient heterogeneous nano catalyst are described. CDSCS has been fully characterized by different microscopic, spectroscopic and physical techniques, including scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic forced microscopy (AFM), X-ray diffraction (XRD), inductively coupled plasma (ICP) analysis, thermogravimetric analysis (TGA) and FT-IR. CDSCS is proved to be a useful heterogeneous nano catalyst in Cu(I)-catalyzed ‘Click’ cycloaddition of organic azides with terminal alkynes. CDSCS catalyzes the 1,3-dipolar cycloaddition reactions of β-azido alcohols and alkynes at room temperature, in THF/H₂O (1:1, v/v) solution. Using CDSCS, 1,4-disubstituted 1,2,3-triazole adducts are mainly obtained, in good to excellent yields and in short reaction times. These compounds have featural resemblance to β-adrenoceptor blocking agents. CDSCS was approved as a chemically and thermally stable nano catalyst that can be reused for many consecutive trials without a significant decline in its reactivity.     

Simplified infeasible interior-point algorithm for SDO using full Nesterov-Todd step

Interior-point methods for semidefinite optimization problems have been studied frequently, due to their polynomial complexity and practical implications. In this paper we propose a primal-dual infeasible interior-point algorithm that uses full Nesterov-Todd (NT) steps with a different feasibility step. We obtain the currently best known iteration bound for semidefinite optimization problems.