Most dental works require a diagnostic impression; alginate is contemplated as the most popular material used for this purpose. Titanium dioxide nanoparticles show evidence of antimicrobial activity in the recent era, for this purpose, this study aimed to evaluate the effect of adding Titanium dioxide nanoparticles on antimicrobial activity and surface detail reproduction of alginate impression material. Materials and methods: Titanium dioxide nanoparticles (purity = 99%, size= 20nm) was added to alginate at three different concentrations (2%, 3% and 5%). 84 samples were prepared in total. Samples were tested for antimicrobial activity using a disc diffusion test, and surface detail reproduction was done using (ISO 21563:2021). One-way ANOVA and independent sample t-test were used for data analysis through SPSS software. Results: for the antimicrobial test, inhibition zones for Streptococcus mutans and Candida albicans showed significant changes concerning the alteration in Titanium dioxide nanoparticle concentrations. The inhibition zone significantly increased with an increase in the percentage of Titanium dioxide nanoparticles. The mean of the inhibition zone for S. mutans was superior to C. albicans and the difference was statistically significant. Regarding surface detail reproduction, the control group, 2% and 3% groups manifested very similar results, only the group to which 5% of Titanium dioxide nanoparticles were added showed a decline in detail reproduction when compared to the other three groups. Conclusion: Within the limitation of this study, we can conclude that the antimicrobial activity against S mutans and C. albicans were significantly increased in modified groups, and this escalation was directly linked to the increase in Titanium dioxide nanoparticles concentration. In contrast, the surface detail reproduction was decreased when adding 5% Titanium dioxide nanoparticles to alginate.
Objectives: This study explored knowledge, attitude, and practice of infection control by dental students at College of Dentistry/ University of Baghdad, Iraq. Material and Methods: Three hundred dental students participated in this study. A self administrated questionnaire with 21 close ended questions related to use of personal protective equipments, infection control awareness, vaccination status, percutaneous exposures, and attitude towards treatment of patients with hepatitis B (HBV)/ or human immunodeficiency virus (HIV) was distributed to dental students. Data were analyzed using Statistical Package for Social Sciences (SPSS) version 21. Fisher exact and Chi-square test were used with significance level set to 0.05. Results: The
... Show MoreThe objective of this study was to determine the concentration of trace element chromium(III) and thyroid peroxidase activity in human serum , and to find a relationship between the concentration of chromium(III) and thyroid peroxidase activity in serum of patients with hypothyroidism, hyperthyroidism and healthy subjects. Serum thyroid peroxidase was measured by enzyme linked radioimmunoassay(ELISA) method and chromium determination was by atomic absorption spectrophotometer .Comparing the values of chromium concentration and thyroid peroxidase activity in both samples showed that there were significant positive correlations between chromium levels and thyroid peroxidase activity(P<0.01, r=0.11).
... Show MoreThe Chemistry of heterocyclic sulphur and nitrogen containing compounds have a great role in the field of scientific studies, The 2-amino 5-mercapto-1,3,4-thiadiazole ring for instance, has gained more importance in recent years because they are considered as potent biologically active nucleus. In this study disulfide derivative can be obtained by oxidation with hydrogen peroxide of thiol group of the heterocyclic 2-amino 5-mercapto-1,3,4-thiadiazole ring to obtain compound (3) with expected antibacterial activity. In order to use it as a diazo component to prepare some new bis azo compounds as possible antibacterial agents, the reaction of two primary amino groups on both sides of disulfide dimer with sodium nitr
... Show MoreIn this work ester derivatives were synthesized by the reaction of imidazole derivatives (C1) with ethylchloroacetate in ethanol and NaOH to give the corresponding (C2) .While compound (C3) acetohydrazide was synthesized by the reaction of ester derivatives (C2) with hydrazine hydrat in ethanol. Compound (C3) from the reaction with different aromatic aldehydes in absolute ethanol gave the Schiff′s bases (C4,C5). The product compounds were characterized by FT-IR, U.V and 1HNMR spectra and the biological activities were studied as antibacterial.
In this paper, an Anti-Disturbance Compensator is suggested for the stabilization of a 6-DoF quadrotor Unmanned Aerial vehicle (UAV) system, namely, the Improved Active Disturbance Rejection Control (IADRC). The proposed Control Scheme rejects the disturbances subjected to this system and eliminates the effect of the uncertainties that the quadrotor system exhibits. The complete nonlinear mathematical model of the 6-DoF quadrotor UAV system has been used to design the four ADRCs units for the attitude and altitude stabilization. Stability analysis has been demonstrated for the Linear Extended State Observer (LESO) of each IADRC unit and the overall closed-loop system using Hurwitz stability criterion. A minimization to a
... Show MoreAlthough its wide utilization in microbial cultures, the one factor-at-a-time method, failed to find the true optimum, this is due to the interaction between optimized parameters which is not taken into account. Therefore, in order to find the true optimum conditions, it is necessary to repeat the one factor-at-a-time method in many sequential experimental runs, which is extremely time-consuming and expensive for many variables. This work is an attempt to enhance bioactive yellow pigment production by Streptomyces thinghirensis based on a statistical design. The yellow pigment demonstrated inhibitory effects against Escherichia coli and Staphylococcus aureus and was characterized by UV-vis spectroscopy which showed lambda maximum of
... Show MoreIn this work silicon solar cell has been used with semicircular grooves to improve its efficiency by reducing reflection of rays and increasing optical path through the cell. Software program for optical design (zemax) has been used by ray tracing mode to evaluate prototype efficiency when using detector beneath the cell. The prototype has aspect ratio (A.R=0.2) which is the best efficiency at incident angle (ϴ=0ͦ) and the best acceptance angle (ϴ=50ͦ).
The current study focuses on the assessment of pollution indicators and health risks of heavy elements in the surface soil of Samarra City. Twelve soil sample collected from different sites in Samarra City, analysis of soil sample to find the heavy metals concentrations which As, Br, Co, Cr, Cu, Mn, Mo, Ni, Pb, Sn, V, Zn, Zr, U, B, Cd, Hg, Th, Ce, La, Th, B, Ba .The results are compared with limit of world standard (12). The higher values which refer to pollution in heavy metal are Cr, Cu, Ni, Zn, Zr, Cd due to industry activity and Hg higher concentration because of Pharmaceutical Industries and Medical Waste . The high concentration in V, Br, Mo, Se, As because of agriculture activity. The enrichment factor calculated
... Show MoreFeed Forward Back Propagation artificial neural network (ANN) model utilizing the MATLAB Neural Network Toolbox is designed for the prediction of surface roughness of Duplex Stainless Steel during orthogonal turning with uncoated carbide insert tool. Turning experiments were performed at various process conditions (feed rate, cutting speed, and cutting depth). Utilizing the Taguchi experimental design method, an optimum ANN architecture with the Levenberg-Marquardt training algorithm was obtained. Parametric research was performed with the optimized ANN architecture to report the impact of every turning parameter on the roughness of the surface. The results suggested that machining at a cutting speed of 355 rpm with a feed rate of 0.07 m
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