In vitro curcumin delivery and antibacterial activity of RuS2 and RuO2 nanoparticles loaded chitosan biopolymer

In this work, RuS₂ and RuO₂ nanoparticles loaded chitosan (Chitosan was extracted from Lobsters shells of Persian Gulf, IR. Iran) was prepared and characterized via FE‐SEM, EDS and FT‐IR analysis. FESEM showed the formation of spherical nanoparticles in size ranging of 20 to 100 mm. Subsequently, the role of these new materials as curcumin drug carrier and in vitro release of curcumin in simulated body fluid (SBF) solution (pH 7.4) were studied. RuS₂‐NPs‐CS than to RuO₂‐NPs‐CS showed higher drug loading efficiency (>91%) and rapid (<90 min) curcumin drug release in SBF solution. Also, antibacterial activity of RuS₂‐NPs‐CS and RuO₂‐NPs‐CS in presens and absence of Rosemary extracts against the gram negative bacteria Pseudomonas aeruginosa (PAO 1) was evaluated by detection of minimal inhibition concentration (MIC) and minimal bactericidal concentration (MBC). MIC of RuS₂‐NPs‐CS, RuO₂‐NPs‐CS and Rosemary extracts on Pseudomonas aeruginosa strains were found to be 50 mg/ml, 50 mg/ml and 1250 mg/ml, respectively. The synergistic effect of these materials for inhibition of PAO 1 growth showed that mixture of RuS₂‐NPs‐CS and Rosemary extracts has a better efficiency than to other mixture materials.     

Biosynthesis of Fe3O4-magnetic nanoparticles using clover leaf aqueous extract: Green synthesis of 1,3-benzoxazole derivatives

In this research, magnetic Fe₃O₄-NP nanoparticles were synthesized employing a green biosynthetic procedure by reduction of ferric chloride solution with clover leaf water extract. The nanoparticles prepared via this biosynthesis method can potentially be valuable for different purposes such as organic synthesis. In this research, 1,3-benzoxazole derivatives were generated via a multicomponent reaction of α-bromo ketones, isothiocyanate, and propiolate in the presence of a catalytic amount of bio-Fe₃O₄ MNPs and sodium hydride in water at 50°C in good yields. The catalyst was reused five times with a minor decrease in its catalytic activity.     

Synthesis and characterization of Si-Zr-Mo nanocomposite as a rapid and efficient catalyst for aromatization of Hantzsch 1,4-dihydropyridines

Nanocomposite of Silica-zirconia-molybdate designated as Si-Zr-Mo was prepared via the reaction of the in situ generated zirconium-tetra octanoxide [Zr(Oct)₄] through condensation of zirconium-tetra-n-butoxide and 1-octanol in a sol–gel method with sulfuric acid and tetraethylorthosilicate (TEOS) followed by grafting of MoO₄^2? on modified silico zirconia nanocomposite under reflux conditions. The prepared nanocomposite was characterized using inductively coupled plasma (ICP), N₂ sorption isotherms, transmission electron microscopy (TEM), and FT-IR spectroscopy. The as prepared nanocomposite had a surface area and pore dimension of 140 m²/g and 1.48 nm, respectively. The morphology of sulphated silico zirconia nanocomposite after immobilization MoO₄^2? has been changed from nanoparticles to nanaorods. It was found that the synthesized nanocomposite successfully catalyze the oxidative dehydrogenation of 1,4-dihydropyridines (1,4-DHPs) with 92–100% conversion and 80–100% selectivity toward the desired products.     

New method to posynomial geometric programming of trapezoidal fuzzy numbers

This paper presents a method for solving posynomial geometric programming with fuzzy coefficients. By utilizing comparison of fuzzy numbers with a method, the programming with fuzzy coefficients is reduced to the programming with constant coefficients. Then the programming with fuzzy coefficients can be solved by using a method for posynomial geometric programming. Finally, one comparative example is used to illustrate advantage of the new method.     

Synthesis and Characterization of Copper Ferrite Nanocrystals via Coprecipitation

Nanocrystalline CuFe₂O₄ powder was prepared by a coprecipitation method from iron chloride and copper chloride in the presence of octanoic acid (C₈H₁₆O₂) as surfactant. The as-prepared samples were characterized by XRD, TEM, SEM, FT-IR and VSM. SEM and TEM indicated that the particles were quasi spherical with the particle sizes in the range of 23±7?nm. The magnetic properties of the sample were measured by using a vibration sample magnetometer (VSM), which showed that the sample exhibited a typical ferromagnetic behavior at room temperature, while present finite coercivity of 245.5?Oe at 300?K.     

Solvent Effects on Tautomeric and Microscopic Protonation Constants of Glycine in Different Aqueous Solutions of Methanol and Ethanol

The acid-base equilibria of glycine have been studied in different aqueous solutions of methanol and ethanol (0?C45?% v/v) using a potentiometric method. In this study, the macro and micro protonation constants of the amino acid and its tautomeric constant have been determined at 25?°C and constant ionic strength (0.1 mol?dm^?3 NaClO₄). The protonation and the tautomeric constants of glycine in different binary mixtures were analyzed in terms of the Kamlet, Abboud and Taft (KAT) parameters. Single-parameter correlations of the constants versus ?? (hydrogen-bond donor acidity), ?? (hydrogen-bond acceptor basicity) and ?? ^? (dipolarity/polarizability) are poor in all solutions. Multi-parameter correlations show better results, but dual-parameter correlations represent significant improvements with regard to the single- and multi-parameter models. Linear correlation is observed when the experimental protonation constant values are plotted versus the calculated ones when the KAT parameters are considered. Finally, the results are discussed in terms of the effect of the solvent on protonation and tautomeric constants.     

Nested splitting CG-like iterative method for solving the continuous Sylvester equation and preconditioning

We present a nested splitting conjugate gradient iteration method for solving large sparse continuous Sylvester equation, in which both coefficient matrices are (non-Hermitian) positive semi-definite, and at least one of them is positive definite. This method is actually inner/outer iterations, which employs the Sylvester conjugate gradient method as inner iteration to approximate each outer iterate, while each outer iteration is induced by a convergent and Hermitian positive definite splitting of the coefficient matrices. Convergence conditions of this method are studied and numerical experiments show the efficiency of this method. In addition, we show that the quasi-Hermitian splitting can induce accurate, robust and effective preconditioned Krylov subspace methods.     

The Sinc-collocation and Sinc-Galerkin methods for solving the two-dimensional Schrödinger equation with nonhomogeneous boundary conditions

In the last three decades, Sinc numerical methods have been extensively used for solving differential equations, not only because of their exponential convergence rate, but also due to their desirable behavior toward problems with singularities. This paper illustrates the application of Sinc-collocation and Sinc-Galerkin methods to the approximate solution of the two-dimensional time dependent Schrödinger equation with nonhomogeneous boundary conditions. Some numerical examples are presented and the proposed methods are compared with each other.