The classification of WebQual dimensions based on the asymmetric impact-performance of Kano\'s customer satisfaction model: A case study of the Tehran virtual university website

The extension of the Internet and World Wide Web has created new opportunities as well as new challenges for institutions and individuals who are either receiving or delivering education. Electronic learning is one of the most important breakthroughs in education in which the website is the first access point that users receive educational services provided. Therefore, website quality should be considered as an important factor resulted in the success of virtual learning and studied in a more detailed manner from the e-learners’ perspective. This paper aims to classify the quality aspects of the Tehran virtual university website (webqual 4.0) according to the Kano model of customer satisfaction and determine the asymmetric impact of the webqual 4.0 dimensions’ performance on overall user satisfaction in order to prioritize those dimensions in resource allocation, as well as sensitize the managers of the mentioned website. This is a descriptive-survey and applied study, and also a cross-sectional one. The study population included Tehran University students studying in virtual courses and the data collection tool was the questionnaire of webqual 4.0, as well as, a researcher-made questionnaire to measure end-user satisfaction. Multiple regression analysis was used to investigate the impact of performance asymmetry. The result showed that usability dimension was the high-performance excitement factor, information quality dimension was a high-performing basic factor, and service interaction dimension had low performance scores and was a basic factor. And finally, a short-term plan to improve service interaction dimension to reduce user discontent and a long-term plan to better both information quality and usability dimensions to increase user satisfaction was proposed

New Strategy of Reducing Biofilm Forming Bacteria in Oral Cavity by Bismuth Nanoparticles

Objective. Enterococcus faecalis and Streptococcus salivarius are the most important species in dental decay and producing biofilm. Treatment with chlorhexidine 2% mouthwash for 7 days is the best way to eliminate these bacteria. However, due to the ability of these bacteria to survive in harsh environments, increasing emergence of bacterial resistance against available antibiotics, and favorable properties of nanoparticles including broad spectrum antimicrobial activity and lower toxicity, we decided to evaluate reducing biofilm forming bacteria in oral cavity by bismuth nanoparticles. Materials and Methods. This was a cross-sectional study of 40 samples isolated from the patients visiting dental clinics in Shiraz in 2019. Samples, which showed growth, were cultured on blood agar plates and incubated for the PCR procedure. Nanoparticle powder was dissolved in high-purity water, and the final concentration of bismuth nanoparticles (BiNPs) was measured with a spectrophotometer. Minimum inhibitory concentration (MIC) of BiNPs against E. faecalis and S. salivarius was determined by the microbroth dilution method according to methods for antimicrobial susceptibility tests. Also, bactericidal assays were conducted in a Mueller-Hinton broth medium and reported as the concentration of BiNPs that reduced the viable bacterial count by 99.9%. Statistical analysis was carried out using SPSS 21 and one-way analysis of variance, and P values less than 0.05 were considered significant. Results. MICs of BiNP suspension against Streptococcus salivarius and Enterococcus faecalis were 2.5 and 5 μg/ml, respectively. Minimum bactericidal concentrations (MBC) of BiNP suspension against Streptococcus salivarius and Enterococcus faecalis were 5 and 10 μg/ml, respectively. Antibacterial activity of BiNPs was compared with chlorhexidine 2%. MICs of BiNPs against Streptococcus salivarius and Enterococcus faecalis were one-twentieth less than those of chlorhexidine. MBC of BiNPs against both pathogens was one-tenth less than those of chlorhexidine. Conclusion. BiNPs were more effective than chlorhexidine, and MIC and MBC of bismuth nanoparticles are lower than those of chlorhexidine