The purpose of this study to synthesize and characterize silver nanoparticles using phenolic compounds obtained from Camellia sinensis, to test the antibacterial properties of biosynthesized nanoparticles on the formation of biofilms in multidrug-resistant Pseudomonas aeruginosa. Ten isolates of P. aeruginosa were obtained from the Genetic Engineering and Biotechnology Institute laboratories of the University of Baghdad. By using the VITEK-2 system and culturing the isolates on cetrimide agar, the diagnosis was confirmed. Camellia sinensis silver nanoparticles (CAgNPs) were created using an extract of the plant's aqueous and methanolic leaves. Based on the results of the nanoparticle synthesis, spherical nanoparticles that may be single or mixed were included in both the aqueous and methanolic extracts of silver nanoparticles. By comparing their retention times to those of the reference compounds, the HPLC findings revealed that two phenolic compounds (gallic acid and caffeine) had been discovered. Utilising the disc diffusion technique, the antibacterial activity of (CAgNPs) was assessed. The results indicated that the methanolic (CAgNPs) extract was more effective than the aqueous (CAgNPs) extract at 375 and 750 ppm, giving the highest inhibition zone 17.67 and 21.33 mm, respectively, when compared to the aqueous (CAgNPs) extract, which produced inhibitory zones 13.00 and 16.33 mm, respectively. The MIC findings indicated that the methanolic CAgNPs extract was more effective than the aqueous CAgNPs extract; the MIC of the methanolic CAgNPs extract was 23.43 μg/ml in all P. aeruginosa isolates, except the isolates No. 9 and 10, which was 11.718 μg/ml. While in the aqueous extract, the MIC in all P. aeruginosa isolates was 187.5 μg/ml, with the exception of isolates No. 9 and 10, which was 93.75 μg/ml. Additionally, the methanolic CAgNPs extract entirely inhibited P. aeruginosa from building a biofilm when used at 23.43 μg/ml. However, at 46.87 μg/ml of the aqueous CAgNPs extract, totally reduced the biofilm forming activity on P. aeruginosa isolates
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Iodine-doped polythiophene thin films are prepared by aerosol assisted plasma jet polymerization at atmospheric pressure and room temperature. The doping of iodine was carried out in situ by employing iodine crystals in thiophene monomer by weight mixing ratios of 1%, 3%, 5% and 7%. The chemical composition analyses of pure and iodine-doped and heat-treated polythiophene thin films are carried out by FTIR spectroscopy studies. The optical band gaps of the films are evaluated from absorption spectrum studies. Direct transition energy gaps are determined from Tauc plots. The structural changes of polythiophene upon doping and the reduction of optical band gap are explained on the basis of the results obtained from FTIR spectroscopy, UV–V
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In this research TiO2 nano-powder was prepared by a spray pyrolysis technique and then adds to the TiO2 powder with particle size (0.523 μm) in ratio (0, 5, 10, 15 at %) atomic percentage, and then deposition of the mixture on the stainless steel 316 L substrate in order to use in medical and industrial applications.
Structure properties including x-ray diffraction (XRD) and scanning electron microscope (SEM0, also some of mechanical properties and the effect of thermal annealing in different temperature have been studied. The results show that the particle size of a prepared nano-powder was 50 up to 75 nm from SEM, and the crystal structure of the powders (original and nano powder) was rutile with tetragonal cell. An improvement in
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