Background: Alzheimer's disease (AD) is a progressive neuropsychiatric disorder that gradually impairs memory and behavioral functions. Amyloid beta (Aβ) is considered as the most toxic substance in the brain of AD patients. Objectives: The present study was designed to evaluate Aβ deposits by Immuno-and Thioflavin S-costaining in the hippocampus of a rat model of AD after intravenous injection of human adipose-derived stem cells (hADSCs). Methods: Thirty-two male rats were included in the four groups of control, sham, AD and hADSCs. The hADSCs characterization was confirmed by the flow cytometry technique. Immuno-and Thioflavin S-costaining was utilized for detecting Aβ plaques in the hippocampus of a rat model of AD following injection of hADSCs. Results: Statistical analysis revealed that Aβ plaques increased significantly in the AD group compared to the control and sham groups. The administration of hADSCs significantly decreased immunoreactivity and Thio-S-positive plaques in the AD group. We also found that the plaques detected by anti-Aβ antibody (immunohistochemical staining) were significantly more than those distinguished by Thioflavin-S in all the groups. Conclusions: Results showed that hADSCs played an effective role in decreasing amyloids aggregation following migration to the hippocampus of the rat model of AD.

In the technology-based organizations that are active in oil industry, the enjoyment of the employees of the specialized knowledge and skills plays a determinative role in their vocational performance. Inter alia the various prerequisites for such specialized skills in the employees, the present study has dealt with the evaluation of the knowledge management effect. The current study paper is an applied research in terms of its objectives and it has been carried out based on descriptive-survey method. The study population included the operational workers of Naft-e-Shomal Excavation Company that reached to a total of 2000 individuals out of whom 322 individuals were selected as the study sample volume based on convenience method. The data collection tool was a standard questionnaire the reliability of which was evaluated based on Cronbach’s alpha method and a value equal to 0.86 was obtained. The data analyses have been undertaken assisted by path analysis and t-test statistical examinations through taking advantage of LISREL software and SPSS software. The results indicated that all four practices of knowledge management (knowledge creation, knowledge storage, knowledge application and knowledge sharing) exert positive and significant effects on the employees’ development of specialized skills. Also, it was figured out that the company is in a good status in terms of both of the abovementioned factors.

The aim of this study was to examine the barriers to use of educational technology in the learning process of primary school students in district 13 of Tehran. This research in terms of purpose is practical, in terms of the title characteristics of the research is descriptive, and in terms of data collection method is a field research. The statistical population is 350 people, consisted of all primary school teachers and administrators for girls in district 13 of Tehran in the academic year of 2016-2017. Random sampling was simple and available. The sample size was calculated about 124 people based on Cochran formula. In this research, a questionnaire was used to collect data. Content validity of the questionnaire was approved by using expert and corrective opinions of some teachers and subject specialists, and to determine the reliability of the questionnaire the Cronbach's alpha coefficient was used. In order to analyze the collected data, the proportional statistical tests such as correlation coefficients and regression analysis were used that in this regard, the spss statistical software was used. The research results showed that 4 human, cultural, and physical factors and courses content can create barriers in the use of educational technology in the process of student learning.

Today, in the highly competitive world of business, having loyal customers is a valuable asset for businesses and companies. In the same vein, the re-purchase intention plays a vital role and identifying and improving its influential factors can boost this valuable asset. Therefore, the main objective of the present study is to study the role of utilitarian, brand value, aesthetic, and the cultural factors on the intention to re-purchase Apple smartphones. This study is applied and has a descriptive-correlative design. The statistical population consisted of approximately 6000 students of management at the Central Branch of Tehran Azad University. The sample size was calculated 361 people using Morgan table. The simple random sampling method used. To test the research hypothesis, structural equation modeling (SEM) by Lisrel has been used. The findings show that product’s design, perceived quality, subjective norms and brand popularity were the factors that have had a positive effect both directly and through the intermediary variable of socio-cultural reputation on the intention to repurchase this product.