In recent years, infectious diseases are increasingly being encountered in clinical settings. Due to the development of antibiotic resistance and the outbreak of these diseases caused by resistant pathogenic bacteria, the pharmaceutical companies and the researchers are now searching for new unconventional antibacterial agents. Recently, in this field, the application of nanoparticles is an emerging area of nanoscience and nanotechnology. For this reason, nanotechnology has a great deal of attention from the scientific community and may provide solutions to technological and environmental challenges. A common feature that these nanoparticles exhibit their antimicrobial behavior against pathogenic bacteria. In this report, we evaluate the antibacterial activity of Ag, Fe and ZnO nanoparticles against both Gram-negative (E. coli and P. aeruginosa) and Gram-positive (Staph. aureus) bacteria, using agar well diffusion method, as well as determine of minimal bactericidal concentrations by the broth dilution method. The results showed that antibacterial activities of these nanoparticles were found active against both Gram-positive and Gram-negative bacteria used in this study. Among the three nanoparticles, Ag nanoparticles have excellent bactericidal potential, while Fe nanoparticles exhibited the least bactericidal activity.
In this work, solid random gain media were fabricated from laser dye solutions containing nanoparticles as scattering centers. Two different rhodamine dyes (123 and 6G) were used to host the highly-pure titanium dioxide nanoparticles to form the random gain media. The spectroscopic characteristics (mainly fluorescence) of these media were determined and studied. These random gain media showed laser emission in the visible region of electromagnetic spectrum. Fluorescence characteristics can be controlled to few nanometers by adjusting the characteristics of the host and nanoparticles as well as the preparation conditions of the samples. Emission of narrow linewidth (3nm) and high intensity in the visible region (533-537nm) was obtained.
With the aim of developing potential antimicrobials, a series of new 5-fluoroisatin derivatives incorporated with different secondary amines (piperidine, morpholine, pyrrolidine, dimethylamine, and diphenylamine) for monomer, and (piperazine) in case of dimer Mannich bases, separately in presence of formaldehyde to obtain Mannich bases of 5-fluoroisatin derivatives, which then each Mannich derivatives reacts with phenylhydrazine to form Schiff bases as final products. The resulting compounds were characterized by two spectroscopic analyses; (Fourier- transform infrared) FT-IR and proton nuclear magnetic resonance spectroscopy (¹H-NMR). In addition, the in vitro antibacterial and antifungal activities were tested against some human pathogen
... Show MoreBackground: The Streptococcus genus are the predominant bacteria in the mouth and the Streptococcus sanguinis is one of them which performing a primary function for expansion of dental biofilm. Gingival and periodontal disorders are caused by dental biofilm, today, there is a necessity to discover naturally presenting antibacterial compounds from herbs with less side effects as a substitutive to the commonly handled chlorohexidine. Thus, the purpose of this study was to assess the antibacterial activity of thymus vulgaris oil on Streptococcus sanguinis bacteria In vitro. Materials and Methods: Human supragingival plaque samples were taken from 10 subjects, then morphological and microscopical examination, bioch
... Show MoreTitanium dioxide nanorods have been prepared by sol-gel template
method. The structural and surface morphology of the TiO2 nanorods was
investigated by X-ray diffraction (XRD) and atomic force microscopy
(AFM), it was found that the nanorods produced were anatase TiO2 phase.
The photocatalytic activity of the TiO2 nanorods was evaluated by the
photo degradation of methyl orange (MO). The relatively higher
degradation efficiency for MO (D%=78.2) was obtained after 6h of exposed
to UV irradiation.
Background: Debonding orthodontic brackets and removal of residual bonding material from the enamel surface include critical steps that may cause enamel damage. The aim of the present study was to evaluate and compare the site of bond failure and enamel surface damage after debonding of three types of esthetic brackets (composite, ceramic, sapphire) bonded with light cure composite and resin-modified glass ionomer adhesive. Materials and methods: Seventy two maxillary premolars teeth were divided into three groups each group consisted of 24 teeth according to the type of brackets. Each group was subdivided into two subgroups (12 teeth for each) according to the bonding material that was used. After 7 days of bonding procedure, the brackets
... Show MoreBack ground: Glass ionomer materials lack resistance to wear and pressure and are susceptible to moisture during the initial stages of setting and dehydration. So this study was done to assess diametral tensile strength and microhardness of glass ionomer reinforced by different amounts of hydroxyapatite. Materials and methods: In this study a hydroxyapatite material was added to glass monomer cement at different ratios: 10%, 15%, 20%, 25% and 30% (by weight). The diametral tensile strength test described by the British standard specification for zinc polycarboxylate cement was used in this study and the microhardness test was performed using Vickers microhardness testing machine and the microhardness values were calculated and statistical c
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Liquefied petroleum gas (LPG), Natural gas (NG) and hydrogen were used to operate spark ignition internal combustion engine Ricardo E6, to compare NOx emissions emitted from the engine, with that emitted from engine fueled with gasoline as a fuel.
The study was done when engine operated at HUCR for gasoline, compared with its operation at HUCR for each fuel. Compression ratio, equivalence ratio and spark timing were studied at constant speed 25rps.
The results appeared that NOx concentrations will be at maximum value in the lean side near the stoichiometric ratio, and reduced with moving away from this ratio for mixture at both s
... Show MoreThis experiment was carried out at the Field of Poultry, Department of Animal Resources, College of Agriculture, University of Baghdad, during the period from 1/5/2011 until 5/7/2011 to study the effect of adding arginine to laying hens diet on certain blood traits. A total of 100 Brown Lohmann laying hen chickens, 38 weeks of age, were randomly distributed into four treatment groups, with 25 hens for each treatment. Treatment groups were: T1: bird-fed diet with no additional arginine (control group); T2, T3, and T4: bird-fed diet supplemented with 0.4, 0.7, and 0.9%, respectively. Therefore, the total amounts of arginine in the four treatments (T1, T2, T3, and T4) become 1.1, 1.5, 1.8, and 2.0%, respectively. Results of this experiment rev
... Show MoreMethotrexate (MTX) is widely used chemotherapeutic agent with different side effects including germ cells toxicities. Silibinin is one of the structural isomers of silymarin, with different phytotherapeutic applications, and its possible protective effects against MTX induced germ cells damage were investigated in this work. Twenty five male mice were divided into five groups (n=5) allocated as follows: Group 1 received buffer for five days given by single intraperitoneal (IP) injection per day; Group 2 in addition to buffer for five days, animals received at day five single dose of 20mg/kg of MTX IP. Groups (3, 4, and 5) received respectively, (50, 100, or 150mg/kg body weight) of silibinin IP single daily dose for five days then at day fi
... Show MoreIn this study, silver-tungsten oxide core–shell nanoparticles (Ag–WO3 NPs) were synthesized by pulsed laser ablation in liquid employing a (1.06 µm) Q-switched Nd:YAG laser, at different Ag colloidal concentration environment (different core concentration). The produced Ag–WO3 core–shell NPs were subjected to characterization using UV–visible spectrophotometry, X-ray diffraction (XRD), transmission electron microscopy (TEM), energy-dispersive spectroscopy, electrical analysis, and photoluminescence PL. The UV–visible spectra exhibited distinct absorption peaks at around 200 and 405 nm, which attributed to the occurrence of surface Plasmon reson