Effect of Hydrogen Peroxide on the Antibacterial Substantivity of Chlorhexidine

The purpose of this in vitro study was to assess the effect of hydrogen peroxide on the antibacterial substantivity of chlorhexidine (CHX). Seventy-five dentine tubes prepared from human maxillary central and lateral incisor teeth were used. After contamination with Enterococcus faecalis for 14 days, the specimens were divided into five groups as follows: CHX, H2O2, CHX + H2O2, infected dentine tubes (positive control), and sterile dentine tubes (negative control). Dentine chips were collected with round burs into tryptic soy broth, and after culturing, the number of colony-forming units (CFU) was counted. The number of CFU was minimum in the first cultures in all experimental groups, and the results obtained were significantly different from each other at any time period (P < .05). At the first culture, the number of CFU in the CHX + H2O2 group was lower than other two groups. At the other experimental periods, the CHX group showed the most effective antibacterial action (P < .05). Hydrogen peroxide group showed the worst result at all periods. In each group, the number of CFU increased significantly by time lapse (P < .05). In conclusion, H2O2 had no additive effect on the residual antibacterial activity of CHX

A direct approach for three-dimensional elasto-static and elasto-dynamic solutions in curvilinear cylindrical coordinates with application to classical cylinder problems

This paper deals with introducing a unique representation of the three-dimensional Navier\u27s equations of motion in cylindrical coordinate system in an exact simplified form without any approximation, aiming at facilitating solution procedure for different 3-D elasto-static and elasto-dynamic problems in the future. A novel form of the 3-D elasticity equations of motion including the body forces in cylindrical coordinate system is derived in an uncoupled form in terms of the longitudinal (axial) displacement component and the \u27r-theta\u27 in-plane anti-symmetric rotation function instead of introducing any additional auxiliary unknown potential function. The other displacement components (i.e., circumferential and radial displacement components) are shown to be obtained from two independent equations in terms of the determined axial displacement and the aforementioned rotation component. The correctness, validity and easy implementation of the introduced elasticity approach for obtaining exact elasticity solutions for various 3-D elasto-static and elasto-dynamic problems are demonstrated through solving a number of known elasticity problems. Three-dimensional static and free vibrations of finitelength solid cylinders as well as thick-walled hollow cylindrical shells are analytically solved. Numerical comparative results and discussion are conducted. Excellent agreement between the obtained results and those reported in the literature is observed in all cases, confirming the validity of the proposed new approach

Video Quality Assessment: Exploring the Impact of Frame Rate

Technology advancements in the past decades has led to an immense increase in data traffic over various networks. Videos constitute a major percentage of this traffic and their share is projected to increase at an accelerating speed in the coming years. Service providers aim to deliver videos that have high quality while at the same time keeping the data rate as low as possible. Effective and efficient objective Video Quality Assessment~(VQA) algorithms are essential in order to provide real time estimate of video quality so that the best compromise between data rate and quality can be achieved. Data rate of video transmission can be altered by controlling different parameters of the video, among which frame rate is one of the most important parameters. So far, only limited works have been done to study the impact of frame rate variations on video quality. The purpose of this work is to investigate the impact of varying frame rate on the quality of videos and to develop novel VQA models that integrate frame rate variations into the task of quality assessment. In order to achieve this goal, we first construct two new video databases that contain videos of diverse content, and spatial and temporal resolutions. We carry out subjective studies on these databases to obtain human opinions on video quality. The subjective study allows us to evaluate the performance of well known objective VQA algorithms on cross-frame rate videos. The results reveal that there is considerable disparity between the subjective scores and the predictions from state-of-the-art objective models that do not take frame rate into consideration. We explore statistical models for video quality analysis. In particular, we conduct cross-frame local phase statistical analysis, which provides new insights on video motion smoothness as an important factor that affects video quality across different frame rates. Our evaluations of the proposed motion smoothness metric using the subject-rated databases show that this novel measure provides a new means to capture the impact of frame rate on video quality, and demonstrates strong promise at improving the performance of objective video quality assessment models. We also propose the notions of perceptual temporal aliasing factor and perceptual spatiotemporal aliasing factor to incorporate the characteristics of human visual contrast sensitivity variations into the framework of spatial and temporal aliasing analysis. We incorporate the proposed aliasing factors into the VQA process to predict the quality of video under frame rate change, resolution change, and lossy compression. Our performance evaluation using the subjective database shows that the proposed perceptual aliasing factors are strong quality predictors across-frame rate, resolution, and data rate, significantly outperforming baseline VQA methods without aliasing modeling

Expand Dimensional of Seismic Data and Random Noise Attenuation Using Low-Rank Estimation

Random noise attenuation in seismic data requires employing leading-edge methods to attain reliable denoised data. Efficient noise removal, effective signal preservation and recovery, reasonable processing time with a minimum signal distortion and seismic event deterioration are properties of a desired noise suppression algorithm. There are various noise attenuation methods available that more or less have these properties. We aim to obtain more effective denoised seismic data by assuming 3-D seismic data as a tensor in order three and increasing its dimension to 4-D seismic data by employing continuous wavelet transform (CWT). First, we map 3-D block seismic data to smaller blocks to estimate the low-rank component. The CWT of the tensor is calculated along the third dimension to extract the singular values and their related left/right vectors in the wavelet domain. Afterward, the effective low-rank component is extracted using optimized coefficients for each singular value. Thresholding is applied in the wavelet domain along the third dimension to calculate effective coefficients. Two synthetic and field data examples are considered for performance evaluation of the proposed method, and the results were compared with the competitive random noise suppression methods, such as the tensor optimum shrinkage singular value decomposition, the iterative block tensor singular value thresholding, and the block matching 4-D algorithms. Qualitative and quantitative comparison of the proposed method with other methods indicates that the proposed method efficiently eliminates random noise from seismic data

Philosophical Explanation of Teacher’s Ethics from the Point of View of Western Educational Philosophers and Muslim Educators and Thinkers in Order to Present a Charter and Validate it

The present study was conducted with the aim of philosophical explanation of teacher’s ethics from the point of view of Western educational philosophers and Muslim educators and thinkers in order to provide a charter and validate it. Descriptive analytical method and focus group method were used to answer the research questions. The results of the surveys showed that the teacher's code of ethics confirmed by philosophers and educators can be designed in three axes of areas, components and indicators. The areas include physical and appearance, doctrinal and moral, scientific, social and political, economic and professional. The components of the first field include "beauty in appearance, beauty of clothing, physical strength and ability, verbal and behavioral ability". The components of the second field include "Godliness, belief and practice of spiritual values, humility, harmony of actions and speech, fairness and magnanimity, equality, friendship and tolerance, love and affection, humanization". The components of the third field include "general knowledge, specialized knowledge, competence in teaching, recognition of individual differences, awareness of growth stages, guidance and correction". The components of the fourth field include "responsibility, social awareness, transfer of cultural heritage, cultural interaction, criticism". And the components of the fifth field include "financial sufficiency and simple living". One hundred and four sub-components were also identified and introduced. The experts in each subject matter confirmed the internal validity of the designed charter and its three cores

Serum Klotho Level and its Related Factors Among Male Opioids Addicts With Normal Renal Function Compared to Healthy Male Non-smokers and Smokers in Tabriz, Iran

Background: Klotho is an aging-suppressor gene that encodes a single-pass transmembrane protein and acts as a hormone. In this study, we aim to investigate the serum α-Klotho level in male opioids addicts with normal kidney function compared to healthy male non-smokers and smokers in Tabriz, Iran. Methods: Participnts were 87 men with normal kidney function referred to Sina Educational Research and Treatment Center in Tabriz, Iran (29 opioids addicts, 29 healthy non-smokers, and 29 healthy smokers). Blood samples were collected to measure the soluble a-Klotho level using an ELISA kit. Furthermore, blood creatinine (Cr) and hemoglobin (Hb) levels was measured. Body mass index (BMI) was also calculated for all participants.Results: In addicts, BMI, Hb, and Cr levels were significantly lower than in healthy non-smokers and smokers, but their Klotho level was higher (P&gt;0.05). The Klotho level in healthy smokers was significantly lower than in healthy non-smokers and addicts. The Klotho level of healthy smokers decreased as the pack year increased, but the duration of opioid addiction had no significant association with the Klotho level. There was no significant difference in the Klotho level between control groups (non-smokers and smokers) and men with addiction to different types of opioids. Conclusion: The Klotho level in male opioid addicts is significantly higher than in smokers. There is a significant negative correlation between BMI and Klotho levels among men with normal BMI and overweight. Further studies are recommended in these fields

The phenotypic and molecular analysis of the production of broad-spectrum beta lactamases (ESBLs) among strains of Escherichia coli isolated from food in Hamedan

Introduction One of the reasons for drug resistance in Escherichiacoli isolates is the production of broad-spectrum beta-lactamases. The widespread use of antibiotics in the agricultural and dairy industry has led to raisingin antibiotic resistance. Therefore, the aim of this study was to investigate the phenotypic and molecular ESBLs production among E. coli isolated from food. Materials and Methods This descriptive cross-sectional study was carried out by 93 E. coli isolated from food and poultry in Hamadan in 2017. Then, the microbial susceptibility of the beta-lactamase producing isolates was determined using the (Combined teat CT) method and according to CLSI (2015) guidelines. Also, molecular identification of genes producing ESBLs (blaSHV, blaCTX-1, and blaTEM-1) was performed by PCR method. Results Evaluation of microbial susceptibility showed that the highest antibiotic resistance was observed for nalidixic acid (%88.4), ampicillin (%76.8), tetracycline (%82.8), and sulfomethoxazole (%67). Resistance to ceftazidime, Cefoxitin, aztreonam, cefotaxime was not observed in this study. The genotypic study by PCR method showed that the frequency of blaSHV, blaCTX-1, and blaTEM-1genes in E. coli isolated from food (%5.37), (%19.35) and (%29.03), respectively. Conclusion E.coli isolated from food showed high resistance to antibiotics such as ampicillin, sulfomethoxazole, and tetracycline. On the other hand, the PCR method is more sensitive than the culture method

Development and validation of a stability-indicating method for the quantitation of paclitaxel in pharmaceutical dosage forms

A simple, rapid stability-indicating isocratic assay has been developed and validated for the determination of Paclitaxel (PTX) in commercial injection formulations. The assay is performed using a Nucleosil RP-18 (5 µm, 250 × 4.0 mm i.d) column protected by a Nucleosil C18 precolumn (5 µm, 4.0 × 4.0 mm i.d.) with a mobile phase of methanol–water (80:20) and UV detection at 230 nm. The method was found to be specific for PTX in the presence of degradation products with an overall analytical run time of ~ 9 min. Accuracy reported as % bias was found to be 0.1–2.5% bias for all samples tested. Intra-assay precision (repeatability) was found to be 0.22–2.65% RSD, while inter-day precision (intermediate precision) was found to be 1.0–3.0% RSD for the samples studied. The calibration curve was found to be linear with the equation y = 29.78x + 7.65, and a linear regression coefficient of 0.9994 over the concentration range 0.05–20 µg/mL. The limits of quantitation and detection were 0.05 and 0.02 µg/mL, respectively. Taxol (30 mg/5 mL), a commercially available dosage form of PTX, was assayed and 100.6–103.6% of the label claim was recovered