فهرست مطالب s.torabi

Infectious bursal disease virus (IBDV) causes a highly contagious disease associated with immunosuppression in young chickens. Production of either egg-based or primary cell-based high-quality vaccines requires time-consuming and costly procedures. To determine a suitable cell line for IBDV replication, L929 cell line was a candidate for the growth kinetics processing of the virus. The L929 cells were proliferated in monolayer, and doubling time was calculated. Replication kinetics an IBDV isolate at the multiplicity of infection 0.1 PFU/cell were determined using virus titration. To adapt IBDV on L929 cells, seven consecutive passages were performed. Virus titer and levels of apoptosis were quantitatively analyzed at each passage. The viral VP2 gene was amplified and sequenced in three passages. An average doubling time of 21 h was estimated for monolayers of L929 cells. Although during early passages, virus growth did not produce a clear cytopathic effect (CPE), an increase in IBDV titers was observed. Serial passages led to the evidence of marked CPEs and an increase in the virus titer in the third passage. During the fourth to seventh passages, consistent CPEs characterized by the formation of granulated and round cells were evident within 24 to 48 hours post-inoculation. The titer of the virus was increased in the third passage onwards to peak in the fourth and constant at 5.9 TCID50 until the end passage. The IBDV replication in connection with DNA fragmentation and FITC, revealed the characteristic picture of apoptosis in a time-dependent manner. We found that the IBDV could easily be adapted to L929 cells, increasing virus yields by about two orders of magnitude. These results indicated that the cell line may be useful in the production of efficient virus particles.

For many years, dexamethasone has been used as an anti-inflammatory drug and is still one of the safest glucocorticoids for treating various diseases. Due to the wide range of the side effects of this drug, it is essential to find a suitable delivering system for reduction in dosage with increased effectiveness. Electrospinning is one of the fiber fabrication methods which is widely used to develop drug carriers due to its ability to load various drugs and biological components and control their release. In this research, neat poly (lactic acid) electrospun fibers and dexamethasone loaded fibers were prepared. To evaluate the effect of polymer concentration on morphology, mechanical properties and drug release profile of the resulting fibers, three polymer concentrations of 10%, 14% and 18% w/v were processed. Thereafter, 5% w/v dexamethasone was added to solutions. The scanning electron microscopy images were investigated to obtain the average diameter of fibers and the average area of pores in each sample. In neat samples, by moving from 10% to 18% composition, the average diameter of the fibers increased by 63.21%. However, in drug loaded samples this increased by 51/19%. After evaluating mechanical properties, an increase of 81/34% in Elastic modulus by moving from 10% to 18% composition was observed. Moreover, the ultimate strength increased by 68/021% when increasing the polymer concentration from 10 to 18%. Drug release from the electrospun samples was continued up to 7 days. Linear release was observed in 10% and 14% compositions. The drug release pattern of these samples was of zero order. Considering the importance of zero order release in different applications of dexamethasone, these delivering systems could be useful. The maximum drug release rate belonged to 14% composition (0.044 1/h).

The present study was done to examine the role of mathematic anxiety on mathematic performance of high school students. Math anxiety is a factor that can affect performance in math. This anxiety is influenced by personal and environmental factors، cultural factors and gender roles too. In this research the effect of this factor son performance in math was assessed. The research method had a correlation design which is categorized in descriptive research. The participants of this study were 300 high school students who were studying in Damghan city high schools in 1389-1390. 150 male high school students and 150 females were selected randomly as sample. The subjects completed the math anxiety Scale (Chiu & Henry، 1990).This scale has four dimensions (mathematics anxiety، learning، problem solving، teacher). Findings showed that among components related to mathematic anxiety، just learning anxiety of mathematic could predict the students’ performance. But there was no difference between male and female students mathematic anxiety.

Breastfeeding and the complementary feeding have a prominent role in the growth and development of children. This survey was designed to assess the nutritional status of children under two years in urban and rural areas of Jahrom.

This was a cross-sectional study on 435 children aged 18-24 months and living in rural and urban areas. Data were collected through a questionnaire and descriptive and analytic statistics were employed.

In this survey, the mean (SD) age of the children was 20.86  3.305 years. Exclusive breast feeding was 55.4 percent and the mean (SD) age of exclusive breastfeeding was 5.49 ± 1.64 years. Moreover, 26.9 percent of the children were fed with artificial milk. The mean (SD) age to start supplementary feeding was 6.040.956 and that of continuation of breast feeding until 2 years of age was18.58  5.321.

Considering the considerable lack of exclusive breast feeding and its resulting complications and consumption of about two times as much artificial milk in the urban as compared to rural areas, it seems that there should be an attempt to educate mothers on the disadvantages of lack of exclusive breast feeding and advantages of breastfeeding specially in rural health care centers.

To study the effects of phytohormone and explant on the callugenesis and regeneration of Sainfoin (Onobrychis sativa L. var. Chadegan) an experiment was conducted in the bitechonolgy laboratory of Sciences and Research Unit,Islamic Azad University, Tehran, Iran in summer and spring of 2006. In this experiment, two phytohormones (2,4-D and BAP(and 4 explants (cotyledon leaf, apical meristem, stem, and root) were used. The highest number of callus was obtained on the MS medium containing 2,4-D (4 mg.l-1) + BAP (1.5 mg.l-1) + apical meristem explant and 2,4-D (2 mg.l-1) + BAP (1 mg.l-1) + apical meristem explant with means of 1.77 and 1.76 callus, respectively. The highest regeneration was obtained in MS medium containing BAP (4 mg.l-1) with mean of 1.6 regenerated plants. A new method for in vitro micropropagation of Sainfoin (Onobrychis sativa Var Chadegan) was developed. Seedlings with root were transferred to greenhouse and continued growing.

The former shtdies and observations indicate that medical shtdents vary considerably in their attitudes towards patients and health care personnel.

To study the attihtde of clerkship students towards select£:d types of patient and selected types of health care personnel.

A quantitative cross-sectional study was conducted among clerkship students. The subjects received a self administered questionnaire with a covering letter explaining the project and outlining terms and conditions for participation. Since twenty-one subjects did not return the questionnaire, data analysis was based on ill questionnaires. The items were 5-poinf Likert-type. The internal consistency of the items was 0.706. Factor analysis was used in order to load the individual attitudinal items into main factors.

There is a significant association between sex and attitudes towards medical personnel. Clerkship students showed a more positive attihtde towards acute illness than chronic illness. The clerkship students responded more positively towards the health personnel than towards the patients. The results are discussed in terms of the impact of clerkship students' attitudes on patients and health personnel. Some possible justifications for these findings are discussed.

Developing key skills within the medical curriculum, especially communication and information technology skills are essential.