Synthesis of novel tetra-substituted benzimidazole compounds containing certain heterostructures with antioxidant and anti-urease activities

A new series of 5,6-dimethyl-2-phenyl-1H-benzimidazole derivatives was synthesized. The antioxidant activities of the synthesized compounds were determined according to the cupric reducing antioxidant capacity (CUPRAC), ABTS, and DPPH assays. Many of the target compounds showed good antioxidant activity. Among these compounds, it has been determined that the carbothioamide and 1,2,4-triazole derivatives had a very good antioxidant capacity. Also, all compounds were screened for in vitro inhibitory activity against Jack bean urease. Among the synthesized molecules, the starting compound, acetate, and acetohydrazide derivatives (with IC₅₀ values 12.02, 11.40, and 8.04 μg/mL, respectively) had a higher inhibitory effect on urease and exhibited a lower IC₅₀ values than acetohydroxamic acid (IC₅₀: 20.50 μg/mL) and thiourea (IC₅₀: 14.04 μg/mL) as a reference inhibitors.     

Stereoselective access to the versatile 4-aminohex-5-ene-1,2,3-triol pattern

We developed a stereocontrolled route allowing potential access to the eight isomers of 4-benzylaminohex-5-ene-1,2,3-triol in two or four steps and ca. 50% yield from readily available chiral nonracemic cis- or trans-alpha,beta-epoxyimine precursors. A new (NH(4))(2)CO(3)-based carboxylation/intramolecular cyclization sequence allowed regio- and stereocontrolled C-3 epoxide opening while neat C-2 hydrolysis was ensured by simple aqueous acidic treatment.     

An extensive FPGA-based realization study about the Izhikevich neurons and their bio-inspired applications

This study is aimed at analysing damping and gyroscopic effects on the stability of parametrically excited continuous rotor systems, taking into account both external (non-rotating) and internal (rotating) damping distributions. As case-study giving rise to a set of coupled differential Mathieu–Hill equations with both damping and gyroscopic terms, a balanced shaft is considered, modelled as a spinning Timoshenko beam loaded by oscillating axial end thrust and twisting moment, with the possibility of carrying additional inertial elements like discs or flywheels. After discretization of the equations of motion into a set of coupled ordinary differential Mathieu–Hill equations, stability is studied via eigenproblem formulation, obtained by applying the harmonic balance method. The occurrence of simple and combination parametric resonances is analysed introducing the notion of characteristic circle on the complex plane and deriving analytical expressions for critical solutions, including combination parametric resonances, valid for a large class of rotors. A numerical algorithm is then developed for computing global stability thresholds in the presence of both damping and gyroscopic terms, also valid when closed-form expressions of critical solutions do not exist. The influence on stability of damping distributions and gyroscopic actions is then analysed with respect to frequency and amplitude of the external loads on stability charts in the form of Ince–Strutt diagrams.

     

Calculation of multicentre nuclear attraction integrals over Slater-type orbitals using unsymmetrical one-range addition theorems

Using the unsymmetrical one-range addition theorems introduced by one of the authors with the help of complete orthonormal sets of Ψα-exponential type orbitals(α = 1,0,1,2,...),this paper presents the sets of series expansion relations for multicentre nuclear attraction integrals over Slater-type orbitals arising in Hartree-Fock-Roothaan equations for molecules.The final results are expressed through multicentre charge density expansion coefficients and basic integrals.The convergence of the series is tested by calculating concrete cases for arbitrary values of parameters of orbitals.     

An effective method for the reduction of the device utilization amount in experimental realization of a fractional-order system

This study focuses on the experimental realization of the fractional-order FitzHugh–Nagumo (FHN) neuron model. Firstly, a second-order approximation function is included to the FHN neuron model to satisfy the fractional-order definition. Since these approximation functions can meet the response of the ideal system only in a limited frequency band, the identification of their center frequency is very critical. Thus, the center frequency ‘ω_c’ of this second-order approximation functions is swept until getting the spiking responses of this neuron model for the first time in this study. After the center frequency is determined, this approximation function is transferred into the ‘z’ domain by employing the Tustin discretization operator. This achieved discrete defined and fractional-order FHN neuron model becomes suitable for implementation on the digital platforms. To verify the proficiency of the proposed sweeping process experimentally, the fractional-order FHN model in ‘z’ domain is implemented on the FPGA platform. After these applications, the order of the approximation function is reduced to one. Once this followed frequency sweeping process is repeated for the first-order approximation, the fractional-order FHN neuron model, which is built by this least-order approximation function, is also implemented with the FPGA. Therefore, the reductions of the device utilization amounts by using this least-order approximation function and the importance of the specific frequency identification process are seen clearly.

     

Application of fuzzy optimization to a supply chain network design: A case study of an edible vegetable oils manufacturer

This study applies fuzzy sets to integrate the supply chain network of an edible vegetable oils manufacturer. The proposed fuzzy multi-objective linear programming model attempts to simultaneously minimize the total transportation costs. The first part of the total transportation costs is between suppliers and silos; and rest one is between manufacturer and warehouses. The approach incorporates all operating realities and actual flow patterns at production/distribution network with reference to demands of warehouses, capacities of tin and pet packaging lines. The model has been formulated as a multi objective linear programming model where data are modeled by triangular fuzzy numbers. Finally, the developed fuzzy model is applied for the case study, compiled the results and discussed.     

A model of consumer choice for national <Emphasis Type="Italic">vs</Emphasis> private label brands

Most consumer choice theory is built around the study of manufacturer brands but in recent years there has been a dramatic rise in the share of private label brands. This empirical study suggests that models of consumer choice need to recognise an asymmetry in competition when both manufacturer and retailer private label brands are available. A nested logit model is introduced which demonstrates asymmetric cross-brand substitutability in this type of market and leads to important implications for strategic brand management.     

SnCl2/EtOH-Mediated Synthesis of Novel 4-Ethoxy- and 4-Chloroindazoles Bearing Sulfonamide Moieties

Abstract

The treatment of N-alkyl-5-nitroindazole with stannous chloride in ethanol, aftercoupling of the obtained amines with arylsulfonyl chloride in pyridine, gave the new 4-ethoxy- and 4-chloroindazoles bearing sulfonamide in moderate to good yields. Chlorination and ethoxylation of indazole were observed during the reduction of the nitro group with anhydrous SnCl₂ in ethanol. The influence of the N-alkylation in N-1 and N-2 position of 5-nitroindazole on the reduction was investigated. The presence ofethoxy group and chlorine atom at position C-4 of indazole was confirmed by x-ray diffraction analysis of compounds 7a and 8a.