Background: Hydroxyapatite nanoparticles have a more surface contact and solubility than conventional hydroxyapatite. Hydroxynanoparticles enhances the biological and mechanical properties of new regenerated tissues. The hydroxyapatite nanoparticles have received attention as a new and effective osseous graft for using as scaffolds in bone regeneration. The reports on hydroxyapatite nanoparticles biocompatibility are controversial. It has been shown that hydroxyapatite nanoparticles induces inflammatory reaction and apoptosis. The aim of the present study was to evaluate the cytotoxicity of nano-hydroxyapatite on the human epithelial cells.
Methods: The study was experimental and completed in vitro. The study was carried out in department of Immonulogy, Faculty of Medicine, Shahid Beheshti University of Medical Sciences in November 2014. The human-derived oral epithelium cell line (KB) obtained from Pasteur Institute, Tehran, Iran were exposed to hydroxyapatite nanoparticles at 0.01, 0.05, 0.1, 0.5, 0.75, 1, 2.5 and 5 mg/ml concentrations in 24, 48 and 72 hours. Rod-shaped hydroxyapatite nanoparticles with 99% purity and maximum 100 nm sized particles were used. Methylthiazol tetrazolium bromide (MTT) method was employed for cell vitality evaluation. Enzyme-linked immunosorbent assay (ELISA) was used for assessing the viability of cells. Distilled water and fetal bovine serum (FBS) were positive and negative controls. ANOVA and Duncan tests were used for statistical analysis.
Results: The cytotoxicity of different concentrations of hydroxyapatite nanoparticles on human-derived oral epithelium cell line in 24 (P< 0.001), 48 (P< 0.001) and 72 hours (P< 0.001) was significantly different. The nano-hydroxyapatite particles at 0.5 to 1 mg/ml had the highest cytotoxicity effect on human-derived oral epithelium cells in 24, 48 and 72 hours. Lower concentrations than 0.05 mg/ml had the best biocompatibility properties in 24, 48 and 72 hours.
Conclusion: Hydroxyapatite nanoparticles had a good biocompatibility. The biocompatibility of hydroxyapatite nanoparticles were dose and time dependent. The lower concentrations than 0.05 mg/ml of nano-hydroxyapatite had the best biocompatibility over time.
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Conclusion: The derived rules also showed that if we use salt and we have diabetes, we are at the risk of developing chronic kidney disease. Moreover, having diabetes can increase the risk of mortality in chronic kidney patients. Aged people should also be more careful about getting chronic kidney disease. Because, they are more prone to develop chronic kidney disease. |
Results: The best performance in terms of accuracy is related to support vector machine techniques in uric acid class, support vector machine in oxalate class and neural network in cysteine class. The worst performance is related to the random forest technique in the citrate class. The safest rules with a 66% confidence level are for the citrate and sodium classes, and the least reliable rule with a 50% confidence level is for the oxalate class.
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Results: Based on used data mining methods findings, factors related to teachers' satisfaction with their performance in providing virtual education were "the possibility of monitoring the performance of homework", "establishing order and regulations", "preparing standard educational content", "using multimedia content", "Mastery of software, educational systems, and multimedia content", and "possibility of examining the quality and quantity of students' learning". Also, interpersonal problem-solving methods, such as "believing in the role of personality traits of people in their behavior", "solving problems with effort and follow-up", "notifying people's mistakes in interpersonal interactions", "giving people the opportunity to check their behavior", "proposing solutions to solve problems for the benefit of both parties", and "dividing big problems into smaller parts" have played a big role in professors' satisfaction about their teaching methods. These characteristics are related to more basic areas such as self-regulation, pursuit and challenge, agreeableness, and realism.
Conclusion: The results of the study showed that the performance of teachers in providing virtual education is influenced by some behavioral factors and individual situational abilities. However, despite the virtual training implementation difficulties, it is a productive opportunity that can be used in the days of returning for conditions (after-covid 19 condition) without physical distance along with face-to-face training. |
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