Background: Radiopacity is one of the prerequisites for dental materials, especially for composite restorations. It's essential for easy detection of secondary dental caries as well as observation of the radiographic interface between the materials and tooth structure. The aim of this study to assess the difference in radiopacity of different resin composites using a digital x-ray system. Materials and methods: Ten specimens (6mm diameter and 1mm thickness) of three types of composite resins (Evetric, Estelite Sigma Quick,and G-aenial) were fabricated using Teflon mold. The radiopacity was assessed using dental radiography equipment in combination with a phosphor plate digital system and a grey scale value aluminum step wedge with thickness varying from 1mm to 10mm in steps of 1mm each. The tested materials were radiographed, we used Image J software, on a computer screen to evaluate the degree of radiopacity for each individual material and compare with the aluminum step wedge. Radiopacity was expressed in mm of equivalent aluminum step wedge. Analysis of varience (ANOVA) and Least Significant Difference (LSD) were used to investigate the significance of differences among the tested groups. Results: Statistical analysis showed highly significant difference among the tested groups (p≤0.01). Amongst, G-aenial composite shows the most radiopaque and it is above or equivalent to that of enamel, while Estelite Sigma Quick composite has the lowest radiopacity value and is equivalent to that of dentin. Conclusion: In line with previous studies, and within the limitation of our study, considerable variations in radiopacity values were found among materials depending on the radiopaque elements incorporated into the matrix. All composite materials tested complied with the ISO 4049 standard.
Five isolates of Gram negative bacteria (Klebsiella pneumoniae, Psuedomonas auroginosa, proteus mirabilis and two strains of E.coli) were in quested for the ability of bearing silver nanoparticles by using LB medium, all the isolates of bacteria were buttered brown color just as soon as mixed the supernatant of bacterial culture with AgNO3 solution, that refered the biosynthesis of Silver nanoparticles (Ag NPs). UV–visible spectrophotometer and Fourier transform infrared (FTIR) spectroscopy were utilized for estimation of (Ag NPs). The five isolates of bacteria were tendered to produce spontaneous mutants by using different kinds of antibiotics, Ampicillin put to use for making mutant in E.coli and Proteus mirabillis, while Pseudom
... Show MoreBackground Numerous studies indicated that workers in the health sector suffer from work stress, hassles, and mental health problems associated with COVID-19, which negatively affect the completion of their job tasks. These studies pointed out the need to search for mechanisms that enable workers to cope with job stress effectively. Objectives This study investigated psychological flow, mental immunity, and job performance levels among the mental health workforce in Saudi Arabia. It also tried to reveal the psychological flow (PF) and mental immunity (MI) predictability of job performance (JP). Method A correlational survey design was employed. The study sample consisted of 120 mental health care practitioners (therapists, psychologists, co
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Consequence of thermal and concentration convection on peristaltic pumping of hyperbolic tangent nanofluid in a non‐uniform channel and induced magnetic field is discussed in this article. The brief mathematical modeling, along with induced magnetic field, of hyperbolic tangent nanofluid is given. The governing equations are reduced to dimensionless form by using appropriate transformations. Exact solutions are calculated for temperature, nanoparticle volume fraction, and concentration. Numerical technique is manipulated to solve the highly non‐linear differential equations. The roll of different variables is graphically analyzed in terms of concentration, temperature, volume fraction of nanoparticles, axial induced magnetic fie
... Show MoreThis work aimed to use conventional PCR to identify Salmonella spp. that were isolated from diarrheal children and healthy and diarrheic dogs based on four virulence genes, hilA, stn, spvR, and marT. Sixteen Salmonella isolates including: 9 isolated from children's diarrhea from three species (S. Typhimurium, S. Enteritidis, S. Typhi) and seven isolated from dogs including (S. Typhimurium, S. Enteritidis, S. Muenchen), were identified primarily by several methods. The PCR products of the 16S rRNA gene were sequenced and examined using BLAST analysis to find differences and similarities between these Iraqi isolates and already-known global strains in order to construct the phylogenetic tree of S.
... Show MoreIn 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.