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Background: One of the main elements that help students in research projects and composing dissertations is the student-supervisor relationship. A valid and reliable tool to measure this seems essential and it is the objective of the present study to validate and assess the psychometric properties of a questionnaire on supervisor-doctoral student interaction (QSDI) in Iran. Methods: Before starting the study, a permission from the developer of the tool was secured. Then the tool was forward-backward translated. After preparing the Farsi version of the tool, content validity was confirmed through qualitative and quantitative methods. To examine construct validity, exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) were conducted with participation of 218 and 410 MD, MSc, and PhD students of medical sciences, respectively. To check reliability of the tool, correlation coefficient was used. To examine internal consistency of the tool, Cronbach's alpha was used. Data analyses were done in SPSS (v.25) and LISREL (v.8). Results: The EFA and CFA results revealed eight factors and 39 items. The value of R-square for the model was equal to 0.99, which means 99% of changes in the dependent variable (supervisor-student interaction) is attributed to the independent variable (41 items). That is, 99% of the dependent variable changes is due to the independent variables. The main indices of the model based on factor analyses were supported (0.9<), which indicated goodness of fit of the model (χ2/df = 1.76, CFI, NFI, TLI = 0.98 GFI = 0.91, RMSEA = 0.043, R-square = 0.99). The significance level for correlation coefficient was below 0.05. Reliability of the tool was supported based on internal correlation (Cronbach's alpha) equal to 0.943 for the whole tool and in 0.89–0.97 range for the subscales. Conclusion: In general, the results showed that the Farsi version of QSDI (eight factors and 39 items) had acceptable and applicable indices and it can be used as a valid tool in different fields for higher education students of medical sciences. [ABSTRACT FROM AUTHOR]

In the present decade, the ever-increasing growth of IT and communication is accelerating and knowledge and information are produced and exchanged more rapidly than before. At present, many organizations, including universities, have employed knowledge management as a mean for their success. This research examined factors affecting knowledge sharing among the students studying e-learning courses in the Tehran University. In terms of the objective, the present study was an applied research and a web-based questionnaire was used to collect information. Ten factors were studied here and according to the structural equation model, indicators of openness and, IT-based communication canals and collaboration have had effective roles in this sharing. [ABSTRACT FROM AUTHOR]

Background: Tea (Camellia sinensis), a well-known beverage is consumed frequently worldwide due to its high antioxidant properties. The present study determines the amount of phytochemicals and antioxidant activities among 12 high yielding tea clones cultivated in Iran. Results: Among the 12 clones studied, tea clone Iran 100 had the highest total phenolic content and total flavonoid content with values of 8.44 ± 1.03 mg gallic acid equivalents per gram dry weight and 4.50 ± 0.16 mg rutin equivalents per gram dry weight respectively. High performance Liquid Chromatography (HPLC) analysis of phenolics and flavonoids in 12 clones revealed the presence of (+)-catechin, (-)-epicatechin, (-)-epigallocatechin, (-)-epigallocatechin-gallate, (-)-epicatechingallate, gallic acid and caffeine. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay showed the existence of variation in the antioxidant activity ranging from 22.67 to 65.36%. The highest antioxidant activity with IC50 value of 218.24 μg/mL was observed in the leaf extract of the clone Iran 100, while the lowest was found in the clone Iran 482 with IC50 value of 234.44 μg/mL. The antioxidant activity had a positive correlation with total phenolic content, total flavonoid content, (-)-epigallocatechin-gallate, (-)-epicatechingallate and caffeine (0.59 ≤ r ≤ 0.97, P b 0.05). Conclusion: From the study it can be concluded that the clone Iran 100 has a superior quality compared to any other clones studied due to occurrence of more phenolic compounds and a greater antioxidant activity. Hence, we recommend the use of tea clone Iran 100 for commercial planting. [ABSTRACT FROM AUTHOR]

The Amygdalus spinosissima (Rosaceae) plant has been used in the Iranian folk medicine as a remedy for the burn wound. Hence, in this study, we aimed to determine the possible medicinal potential of the plant focusing on the root part. The bioactive phenolic and flavonoid compounds present in the root extract of the Amygdalus spinosissima plant as well as its antioxidant and anti-inflammatory properties were determined. Moreover, the effects of root extract on learning and memory in mice were evaluated. The results revealed that the root methanolic extract contained phenolic and flavonoid compounds including apigenin, quercetin, rutin, kaempferol, gallic acid, syringic acid, ferulic acid, and ellagic acid. The extract possessed antioxidant, acetylcholinesterase (AChE), and butyrylcholinesterase (BChE) inhibitory activities in vitro. These biological activities were attributed to the presence of phenolics and flavonoids. The A. spinosissima root extract improved learning and memory function in scopolamine-induced memory dysfunction in mice as determined using the Morris water maze task. The extract modulated the AChE, BChE, and inflammatory genes and enhanced the expression of the antioxidant enzymes in the brain. Consequently, A. spinosissima root extract could be considered as a promising source of potent bioactive compounds in the retarding the development of neurodegenerative diseases such as Alzheimer's disease., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: Human papillomavirus (HPV) is a sexually transmitted virus and related to the development of cervical cancer (CC). To determine the association between high-risk HPV types and CC, we undertook a systematic review and meta-analysis of recently reported prevalence of HPV16 and 18 in Iranian women identified with cervical infections., Materials and Methods: Prevalence studies were identified between 2002 and 2018 using several databases including Medline, Web of Science, Embase, Google Scholar, Iranmedex, and Scientific Information Database., Results: For patients with CC, 57% (95% confidence interval [95% CI] = 43.7%-70.4%) were HPV positive, 48.5% (95% CI = 31.8%-65.2%) were HPV16 and 12.5% (95% CI = 8.8%-16.2%) were HPV18 positive., Conclusion: The results from meta-analysis indicate a relatively high prevalence of high-risk HPV among women infected with CC., (Copyright © 2019 Elsevier Inc. All rights reserved.)