Synthesis of Depo‐Medrol–chitosan hydrogel as new drug slow‐release appliance and investigation of release kinetics by high‐performance liquid chromatography

The present study deals with preparation and optimization of a novel chitosan hydrogel‐based matrix by suspension cross‐linking method for controlled release of Depo‐Medrol. The controlled release of Depo‐Medrol for effective Rheumatoid arthritis disease has become an imperative field in the drug delivery system. In this context, it was intended to optimize loading circumstances by experimental design and also study the release kinetics of Depo‐Medrol entrapped in the chitosan matrix in order to obtain maximal efficiency for drug loading. The optimum concentrations of chitosan (2.5 g), glutaraldehyde (3.05 μL) and Depo‐Medrol (0.1 mg) were set up to achieve the highest value of drug loaded and the most sustained release from the chitosan matrix. In vitro monitoring of drug release kinetic using high‐performance liquid chromatography showed that 73% of the Depo‐Medrol was released within 120 min, whereas remained drug was released during the next 67 h. High correlation between first‐order and Higuchi's kinetic models indicates a controlled diffusion of Depo‐Medrol through the surrounding media. Moreover, recovery capacity >82% and entrapment efficiency of 58–88% were achieved under optimal conditions. Therefore, the new synthesized Depo Medrol–chitosan is an applicable appliance for arthritis therapy by slow release mechanism. Copyright © 2016 John Wiley & Sons, Ltd.     

The exponentiated generalized power Lindley distribution: Properties and applications

In this paper, we introduce a new extension of the power Lindley distribution, called the exponentiated generalized power Lindley distribution. Several mathematical properties of the new model such as the shapes of the density and hazard rate functions, the quantile function, moments, mean deviations, Bonferroni and Lorenz curves and order statistics are derived.Moreover, we discuss the parameter estimation of the new distribution using the maximum likelihood and diagonally weighted least squares methods. A simulation study is performed to evaluate the estimators. We use two real data sets to illustrate the applicability of the new model. Empirical findings show that the proposed model provides better fits than some other well-known extensions of Lindley distributions.     

Preparation and characterization of Cu (II) Schiff base complex functionalized boehmite nanoparticles and its application as an effective catalyst for oxidation of sulfides and thiols

The synthesis, characterization, and evaluation of a Schiff base Cu (II) complex functionalized boehmite nanoparticles (Cu-complex-boehmite) as a new catalyst for oxidation of sulfides and thiols in the presence of hydrogen peroxide with complete selectivity and high conversion under solvent-free and mild reaction conditions were reported. Characterization of the catalyst was performed with various physicochemical methods. This effective catalyst was evaluated in terms of activity and reusability. It indicated high catalytic activity, good recoverability and reusability, and supplied the corresponding products in high yields and short reaction times. In addition, it shows notable advantages such as simplicity of operation, heterogeneous nature, easy work up, and it could be used at least eight times with no significant loss of its activity.     

Facile and Rapid Synthesis of 4,5-Dihydrothiazol-2-ylamine Derivatives via Reaction Between Thiourea and Diaroylacetylenes

Heterocyclic systems 4,5-dihydrothiazol-2-ylamine derivatives are synthesized via an intramolecular thioiminoformamide annulation reaction.     

Investigation of entrance effects on particle electrophoretic behavior near a nanopore for resistive pulse sensing

Resistive pulse sensing using solid-state nanopores provides a unique platform for detecting the structure and concentration of molecules of different types of analytes in an electrolyte solution. The capture of an entity into a nanopore is subject not only to the electrostatic force but also the effect of electroosmotic flow originating from the charged nanopore surface. In this study, we theoretically analyze spherical particle electrophoretic behavior near the entrance of a charged nanopore. By investigating the effects of pore size, particle–pore distance, and salt concentration on particle velocity, we summarize dominant mechanisms governing particle behavior for a range of conditions. In the literature, the Helmholtz–Smoluchowski equation is often adopted to evaluate particle translocation by considering the zeta potential difference between the particle and nanopore surfaces. We point out that, due to the difference of the electric field inside and outside the nanopore and the influence from the existence of the particle itself, the zeta potential of the particle, however, needs to be at least 30% higher than that of the nanopore to allow the particle to enter into the nanopore when its velocity is close to zero. Accordingly, we summarize the effective salt concentrations that enable successful particle capture and detection for different pore sizes, offering direct guidance for nanopore applications.     

A novel method for non-destructive Compton scatter imaging based on the genetic algorithm

Compton scattering tomography is widely used in numerous applications such as biomedical imaging, nondestructive industrial testing and environmental survey, etc. This paper proposes the use of the genetic algorithm (GA), which utilizes bio-inspired mathematical models, to construct an image of the insides of a test object via the scattered photons, from a voxel within the object. A NaI(Tl) scintillation detector and a 185 MBq ¹³⁷Cs gamma ray source were used in the experimental measurements. The obtained results show that the proposed GA based method performs well in constructing images of objects.     

SYNTHESIS OF DIASTEREOMERIC ETHYL 1-BENZOYL-6-(BROMOMETHYL)-2,2,2,4-TETRAPHENYL-3,7-DIOXA-2λ5-PHOSPHABICYCLO- [3.2.0]HEPT-4-ENE-6-CARBOXYLATE

Stable diastereomeric ethyl 1-benzoyl-6-(bromomethyl)-2,2,2,4-tetra- phenyl-3,7-dioxa-2λ ⁵ -phosphabicyclo[3.2.0]hept-4-ene-6-carboxylate was obtained in 98% yield from the reaction between dibenzoylacetylene as electron-deficient acetylenic compound, and ethyl 3-bromopyruvate in the presence of triphenylphosphine in dry ether.