Multi-component reaction synthesis of novel 3-phenyl-3,4-dihydro-2H-benzo[a][1,3] oxazino[5,6-c]phenazine derivatives catalyzed by reusable ZnO-PTA@Fe3O4/EN-MIL-101(Cr) nanopowder at room temperature

ABSTRACT

A simple, one-pot procedure for the synthesis of novel 3-phenyl-3,4-dihydro-2H-benzo[a][1,3] oxazino[5,6-c]phenazine derivatives by four-component coupling reaction between benzo[a]phenazine-5-ol, formaldehyde and amine in the presence of a catalytic amount ZnO-PTA@Fe₃O₄/EN-MIL-101(Cr) nanopowder in ethanol at room temperature under stirring condition. ZnO-PTA@Fe₃O₄/EN-MIL-101(Cr) An inorganic magnetic catalyst was analyzes and described by the XRD, TEM, FESEM, TGA, AFM, VSM and ICP-OES. This study presents simple, efficient, and one-pot multicomponent protocol, which provides several advantages such as short reaction times, high yields, easy working up, chromatography-free technique, catalyst recovery, and reusability are other highlights of this work.     

A prototype of an extrapolation chamber for beta radiation beams of 90Sr+90Y

Extrapolation chamber is the only primary standard dosimeter for beta radiation. With the aim to test new configurations and materials using easily-available and low-cost materials and fulfill the need of a chamber for scientific metrological purposes, in this paper the prototype of an extrapolation chamber has been built and its performance has been investigated in the beta radiation field of ⁹⁰Sr+⁹⁰Y. The main differences between the chamber and commercially available chambers are the geometry, constituent material and configuration. The obtained results were compared with those of the calibration certificate of the source and an agreement within 4 % was verified. The depth-dose curve was also obtained and compared with the curve published in ISO 6980, showing a good agreement. Moreover, Monte Carlo simulation was undertaken using MCNP4C code and the relative difference of 0.3 % was observed compared to the experiment. All of the results proved the suitability of the chamber in the beta radiation field of ⁹⁰Sr+⁹⁰Y.     

Preparation of Carvedilol Nanoparticles by Emulsification Method and Optimization of Drug Release: Surface Response Design Versus Genetic Algorithm

The objectives of this research were the production of Eudragit nanoparticles of carvedilol, an anti-hypertension drug, for enhancement of its absorption and optimization of drug release. Nanoparticles were prepared by emulsification-solvent evaporation or diffusion methods. The statistical surface response design, based on the Box-Behnken model, was applied to evaluate the effect of four variables, each in two levels, on specifications of nanoparticles. An intelligent modeling system was established according to genetic algorithm to predict drug release from the nanoparticles. The neural network-genetic algorithm model showed a more precise method than surface response design in the prediction of the release properties of carvedilol from Eudragit nanoparticles.     

Microfluidic Studies of Carbon Dioxide

Carbon dioxide (CO₂) sequestration, storage and recycling will greatly benefit from comprehensive studies of physical and chemical gas–liquid processes involving CO₂. Over the past five years, microfluidics emerged as a valuable tool in CO₂‐related research, due to superior mass and heat transfer, reduced axial dispersion, well‐defined gas–liquid interfacial areas and the ability to vary reagent concentrations in a high‐throughput manner. This Minireview highlights recent progress in microfluidic studies of CO₂‐related processes, including dissolution of CO₂ in physical solvents, CO₂ reactions, the utilization of CO₂ in materials science, and the use of supercritical CO₂ as a “green” solvent.     

Preparation, characterization and thermal studies of some transition metal ternary complexes

Ternary complexes of Co(II), Ni(II), Cu(II) and Zn(II) with nitrilotriacetic acid as a primary ligand and glycine as secondary ligand were prepared in slightly acid medium. Their molecular masses were determined by acid-base titration against standard potassium hydroxide solution. Their molecular structures were found to be [M (HNTA)(glyH)(2H₂O)]. Thermogravimetric analysis confirmed this structure and that the water present is coordinated to the central metal atom. UV-Vis spectra showed that the complexes have octahedral symmetry. IR spectra suggested the presence of intermolecular hydrogen bonding. This phenomenon was supported by mass spectra. The ionization constants of these complexes, as diprotic acids, were determined.     

Piroxicam/β-cyclodextrin complex included in cellulose derivatives-based matrix microspheres as new solid dispersion-controlled release formulations

New formulations capable to enhance piroxicam (PRX) water solubility and at the same time to control and adjust its release have been developed. For this purpose, two methods have been used and combined to achieve this goal, namely complexation and microencapsulation by O/W emulsion solvent evaporation. In order to modify the drug release, first, microparticles composed of pure PRX and ethylcellulose (EC) or mixtures of EC and hydroxypropylmethylcellulose (HPMC) were prepared, and then, other micropaticles containing the β-cyclodextrin/piroxicam (β-CD/PRX) complex obtained by the solvent evaporation technique and EC or a mixture of EC and HPMC were produced and tested. These formulations were characterized by FT-IR, XRD, optical microscopy, and SEM methods. Drug dissolution tests were carried out in acidic media at pH = 1.2 and 37°C. Depending on the microparticles composition, their size (d₁₀) ranged between 49 μ.m and 121 μ.m and PRX_loaded varied from 10.8 % to 27.7 %. The effect of complexation and HPMC polymer on the drug release was investigated; the results demonstrated that the Higuchi’s release constant significantly increased when using the EC/HPMC mixture as a matrix with pure PRX or only EC as a matrix with the β-CD/PRX complex. The results are remarkably promising since the combination of these processes provided new SD-CR formulations of piroxicam which enabled simultaneous enhancement and control of its release from the carriers.     

DFT Investigation of the Potential of B<Subscript>21</Subscript>N<Subscript>21</Subscript> and Al<Subscript>21</Subscript>P<Subscript>21</Subscript> Nanocages as Anode Electrodes in Metal Ion Batteries

In present paper, the potential of B₂₁N₂₁ and Al₂₁P₂₁ nanocages as anode electrodes of Li-ion, Na-ion and K-ion batteries by using of density functional theory was investigated. The effects of adoption of B₂₁N₂₁ and Al₂₁P₂₁ nanocages with halogen atoms on potential of metal-ion batteries were examined. Results showed that Al₂₁P₂₁ as anode electrode in metal ion batteries has higher potential than B₂₁N₂₁. Results indicated that K-ion battery has higher cell voltage than Li-ion and Na-ion batteries. Results showed that adoption of B₂₁N₂₁ and Al₂₁P₂₁ with halogen atoms increased the cell voltage of metal-ion batteries. Results showed that F-doped metal-ion batteries have higher cell voltage than Cl- and Br-doped metal-ion batteries. It can be concluded that F–Al₂₀P₂₁ as anode electrode in metal-ion battery has higher potential than F–B₂₀N₂₁.