فهرست مطالب علیرضا زنگی ابادی

Because of exiting uncertainties in growth and maintenance of muscle mass processes, particular atrophy inducing inactivity, the aim of the present study was to investigate changes in the expression of atrogenic genes in the muscle of the rat in which the hind-limbs were kept under unloaded conditions.

For this purpose, 10 male Wistar rats were assign in two groups of suspension (n=5) and control (n=5) and the suspension group rats were kept for two weeks in this conditions. After 14 days, the soleus muscle was extracted and the expression of TRAf6 and MuRF1 genes was measured by real-time-Pcr method.

The results of this study showed that after 14 days of hind-limb suspension, the relative weight of soleus muscle was significantly decreased (P=0.009). In addition, the expression of TRAF6 gene was significantly increased (P=0.033), but MuRF1 was not statistically significant (P=0.061).

Therefore, according to the results of this study, it can be stated that TRAF6 and its downstream factor, MuRF1, can be involved in the regulation of muscle mass in conditions of reduced muscular activity and mechanical unloading and as candidates for controlling muscle mass in conditions such as athlete's hospitalized after sports injuries or hind-limb unloading after injury to be considered.

The strength of the reinforcing fibers is the main factor affecting the strength of the composites، therefore، accurate method for measuring the strength is needed. There are two methods for determining the strength of the reinforcing fibers (e. g. carbon fiber). They are the methods of single filament and the fiber tow test (fibers impregnated with resin). The main goal of this research is to find the correct procedure of testing carbon fibers with two different methods of single filament and fiber tow test، so comparing the mechanical properties of two types of PAN based carbon fibers given by those methods. The fibers used in this research were two types of carbon fibers and their mechanical properties like tensile strength، tensile modulus، breaking strain and fracture energy were studied in both test methods. The results show that although the single filament test method is quite difficult but compared with the fiber tow test method gives higher values for tensile strength and fracture energy whereas lower value for tensile modulus and breaking strain.