فهرست مطالب salimi

If professional competencies were of any importance in any educational environment, they would be clearly and emphatically covered in teacher training and in-service training programs in that environment, leading to a common perception among both working teachers and student-teachers. To explore this situation here in Kordestan, a group of 16 student-teachers and 15 working teachers were interviewed in a semi-structured manner. Data analyses led to the identification of themes and their classification across both groups. Comparison of the two sets of data reveals that the student-teachers perceive professional competency to be having a teacher’s characteristics, professional preparedness, response to the changing environmental demands, and the ability in interacting and communicating with others positively. The other group, on the other hand, perceive competency as being able to impact the environment and the potential beneficiaries, knowledge and ability to communicate positively, appearing in multiple roles, and abiding by the professional principles.

In order to reduce the adverse effects of intersections, intelligent systems and the alignment of lights can be used. The BITS system is a localized version of SCATS and SCOOT systems. The aim of this study was to evaluate of BITS system on traffic and environmental variables. The system was evaluated in both cases of coordinated and isolated signals. Traffic variables include line length, delay time, stop time, travel time, and average speed. Environmental variables include fuel consumption, air pollution caused by carbon monoxide, hydrocarbons, and nitrogen oxides, and noise pollution. Prescheduled, intelligent, and coordinated control systems were compared by collecting field data on the traffic flow rate, travel time, and air and noise pollution and simulation in AIMSUN software in three four-way and two three-way intersections in Yazd, Iran. The results showed that all variables were significantly improved in the isolated intelligent control system compared to the isolated prescheduled control system, and the coordinated prescheduled control system performed better than the isolated prescheduled control system. The isolated intelligent control system showed the best traffic and environmental performance. In addition, line length and stop time were the most affected. Compared to other variables, these two could mostly be measured through drivers’ perceptions. According to the above, using BITS intelligent traffic signals and coordinating nearby intersections – the green wave in successive intersections – can prevent the waste of time and national resources. More immediate effects are reduced air and noise pollution, and reduced delay.

Now day, using of stem cells and nanoparticles in the differentiation of stem cells is considered as a therapeutic approach. The purpose of this study was to synthesize and characterize nanocomposite polyacrylic polycarboxylic acid containing nanoparticles of biologically active glass 45S5 crushed and assessment effect of this composite on the propagation and growth of bone marrow derived mesenchymal stem cells in the external environment.
 

In this experimental study, the bioactive glass nanoparticles were synthesized by planetary milling and coated on electrospun polyolactic acid nanofibers. The physicochemical and biological properties of the composite nanocarbon were evaluated by X-ray diffraction, scanning electron microscopy, MTT, acridine orange, and alkaline phosphatase assays.
 

The physicochemical properties showed that the structure of synthesis bioactive glass and the lactic acid poly lactic acid fibers were completely nano size and the uniform distribution of nanoparticles was well placed on the fiber. The cell analysis demonstrated the significant increase proliferation and differentiation of mesenchymal stem cells to bone cells.In the MTT assay, cell survival was expressed in the composite nanostructure after 7 days of cell culture (1.96 ± 0.2), while the control sample (0.76 ± 0.08).
 

According to the results of this study, the composite nanoscale composite is not cytotoxicity effects and has biocompatible. It is useful in bone tissue repair.

In this research, the effect of time (10, 15, 20, 25 and 30 min) and temperature (35, 45, 55, 65 and 75 oC) of ultrasonic waves, ethanol to water ratio (20, 35, 50, 65 and 80%) of extracting solvent and dry matter to solvent ratio (1:5, 1:10, 1:15, 1:20 and 1:25 mg/ml) was investigated on total phenol and flavonoids and antioxidant capacity (in two methods of DPPH and FRAP) of hydroalcoholic extract of celery (Apium graveolens L.) aerial parts by using the response surface method. Based on the results, ultrasound for 10 min at 55 °C, ethanol to water ratio of 80%, and dry matter to solvent ratio of 1:5 were considered as the best treatment. The highest amount of total phenol (471.1 mg GAE/g DW) and flavonoid (187.7 mg quercetin/gDW) content, and antioxidant activity of the extract was obtained under optimized conditions using DPPH (68.5%) and FRAP (4210.4 μM Fe+2/50 μl extract). In general, the high values of adjusted R2 and P-value in fitting models indicated that the drawn models of response surface were ideal. In other words, the high amounts of these parameters indicate the existence of a correlation between the observed values and the predicted ones.