Islamic Azad University North Tehran Branch

About: Islamic Azad University North Tehran Branch is a education organization based out in Tehran, Iran. It is known for research contribution in the topics: Adsorption & Catalysis. The organization has 868 authors who have published 968 publications receiving 9987 citations.

A theoretical study of the intramolecular proton transfer and calculation of the nucleus independent chemical shift in juglone and some of its derivatives

Abstract: In the present study, first, the intramolecular proton transfer (IPT) process of juglone and its derivatives were theoretically investigated in the gas phase and the effect of electron-withdrawing and electron-releasing substi- tuents in different positions of the phenyl and benzoquinone rings of juglone on the IPT process was studied in which the geometries, energies and thermody- namic functions of the compounds were obtained using density functional theory (DFT) calculations at the B3LYP/6-31+G(2d,p) level. Next, the influ- ence of IPT on changing the aromaticity of the phenyl and benzoquinone rings was investigated. To determine the aromaticity of the rings, nuclear indepen- dent chemical shift (NICS) values were calculated for the ground state and transition state structures (GS1, TS and GS2) using the continues set of gauge transformations (CSGT) procedure at the B3LYP/6-311+G(2d,p) level.

Synthesis of Silica Nanostructures and Optimization of their Size and Morphology by Use of Changing in Synthesis Conditions

Abstract: The aim of the present research was optimization of practical conditions of the sol-gel synthesis. In so doing, silica particles were synthesized using sol-gel method and their size and morphology were investigated by use of SEM and TEM images. The effect of changing molar ratio of reactive including acids and silica pre-matter on the particles' morphology and size was studied. Also, acid type and silica pre-matter used in reaction was examined and the result product of the reaction were investigated in the presence of several acids and two types of silica pre-matter. The reaction time was studied as a very important factor in products' digestion phase which plays a significant role in determining particles’ size and rate of cracking products. Finally, in optimized conditions 50-80 nm diameter nanostructures were synthesized. These products can be used as drug delivery systems.

Characterization of aminoglycoside resistance mechanisms in Acinetobacter Baumannii isolates from burn wound colonization.

Abstract: Clinical isolates of Acinetobacter baumannii have a tendency to develop antimicrobial resistance against commonly prescribed antimicrobial agents, including aminoglycoside agents, particularly in hospitalized patients worldwide. Resistance mechanisms of the bacterium to aminoglycosides are diverse and commonly involve production of aminoglycoside-modifying enzymes and efflux systems. The aim of this study was to investigate the frequency of gene encoding aminoglycoside-modifying enzymes and expression level of adeB efflux gene in A. baumannii isolates recovered from burn wound colonization. A total of 47 clinical isolates of A. baumannii were obtained from burned patients admitted to the Burns Teaching Hospital, Tehran, in 2018. Standard antimicrobial susceptibility screening was performed to determine resistance pattern. A polymerase chain reaction (PCR) assay was performed to determine aminoglycoside-modifying genes ACC(6'), aph(3')-Via, aph(3')-IIb, aadA1, aphA1 and aph6. Semi-quantitative RT-PCR was also carried out to quantify the expression level of the adeB gene. According to the results of the present study, the acc(6') was the predominant aminoglycoside-modifying enzyme gene (80.9%), followed by aph(3')-via, aph6, aph(3')-IIb and aphA1, which was detected in 59.6%, 42.6%, 14.9% and 14.9% of isolates, respectively. None of the A. baumannii isolates harboured the aadA1 gene. The up regulation of adeB gene expression was observed in 63.8% of strains. Moreover, we indicated that there is a relationship between adeB expression and high resistance to gentamicin. Our results revealed that aminoglycoside resistance could be explained by the production of one or a combination of known aminoglycoside-modifying enzymes rather than overexpression of adeB.