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The stability of recombinant proteins has become an increasingly important as more protein therapeutics are developed.In this study, the stability of recombinant human interferon gamma was investigated under storage condition for 0-9 months after production time at 4 and 25℃. The evaluation of biological activity, covalent dimerization, deamidation and oxidation of protein was done by cell culture, HPLC and SDS- PAGE. The results showed represents that antiviral activity was not decreased at 4℃ but decreased as temperature increased to 25℃. The inormation rate of deamidated and oxidized forms and covalent dimers at 25℃ was more rapid than 4℃. Therefore, rhIFN-γ has high stability at 4℃ comparing to 25℃.

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Nowadays, biological substances have allocated many applications to themselves in distinct industries. In this field, biological molecules with various potentials have been identified, from which we can refer to bacteriorhodopsin (BR). Bacteriorhodopsin is found in purple membrane of halobacterium salinarum. Due to its stability and various characteristics like possession of properties of a proton pump, bacteriorhodopsin has many applications in different industries. One of the most important industrial and semi-industrial production processes for bacteriorhodopsin is the isolation and purification of the purple membrane. In this investigation, after halobacterium salinarum culture, the purification was done according to the Yucel method. So as to produce bacteriorhodopsin in semi-industrial scale, a modified method was developed by substitution of mechanical approach with enzymatically method to destruction of DNA and uses of osmotic shock instead of dialyze. This method led to decrease of time and isolation cost in comparison to Yucel method. The contamination percentage of the PM was estimated below 5% for both methods. The purification percentages were 67±1% and 68±4% for the modified method and Yucel method, respectively, which is indicating of the equal purification percentage for both methods. Bacteriorhodopsin amount was 8.2±0.4, 8.1±0.6 mg per liter for the improved method and Yucel method, respectively. The enzyme activity assay by Kuyama method indicated that the pH variation was 1 unit with the same BR amount for both methods. Hence, the modified method introduced in this investigation could reduce time and costs of the purification by maintaining the BR characteristics.

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In this research, the modeling with Artificial neural network and Multilayer – Perceptron were used in order to evaluate the zeolite and citric acid's usage in reducing of Aflatoxin's production in stale dry breads across the Mashhad. Since, the stale breads are the main sources of the livestocks's feeding, and because of the availability of proper environmental conditions for growing molds, these breads are severely contaminated by mycotoxin and especially Aflatoxin, and this make some anxieties about the human being and animal's life. So, the foodstuff's contamination by mycotoxin, should be controlled accurately through the food chain. The results have shown that modelling with ANN is a suitable method especially in food industries, and also the addition of zeolite as compared with Citric Acid, cause the َAflatoxin to reduce more. In this manner, the interaction of zeolite and citric acid caused the Aflatoxin to decrease more, than when zeolite or citric acid are being used alone. Based on these results, Artificial neural network model for zeolite with one hidden layer, hyperbolic tangent function as the transfer function, Levenberg-Marquardt method as the learning rule, 3 hidden neurons, %60 for training subset and %20 for each of validation and test subsets with the correlation coefficient 0/973 had the best overfiting. The modeling results indicate that there is an excellent compatibility between the experimental and predicted values of Aflatoxins.  

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Reinforced concrete structures are one of the most commonly used structures all over the world. However, the high nonlinear behaviour of this kind of structures still needs more research, e.g to shed light into the effects of nonlinear modelling and the structure characteristics. One of the most common methods to predict the nonlinear response of concrete structures is the simplified nonlinear spectra. The nonlinear spectra have been widely used in the seismic design and rehabilitation procedures e.g, ATC40 and FEMA 274. A set of closed-form formulas have been proposed in this manner to predict the strength reduction factor for a given period and ductility. The design and rehabilitation procedures can significantly simplified by using this kind of closed-form formulas. The aim of this paper is to evaluate the seismic behaviour of a set of 4620 single-degree-of-freedom (SDOF) oscillators, which was taken into account based on their period, damping and nonlinear backbone curve parameters. Eleven different periods, three damping ratios, five cracking states, seven ductility ratios, five hardening slopes and two collapse negative slopes were taken into account to cover a wide range of nonlinear behaviour of oscillators. The all combination of nonlinear characteristics with eleven periods and three damping ratios produces 4621 different oscillators to be investigated. The SDOF oscillators were analyzed for two sets of ground motion records which are representative of far and near field records. The far-field records contain 30 strike-slip records with moment magnitude of 6.5 to 6.9. The records are corresponding to the firm soil without any directivity effects. The near-field set contain 31 strike-slip records corresponding to four different earthquake events. They were all recorded within 16 kilometre of the earthquake epicentre. The incremental dynamic analysis was employed to calculate the system demand ductility in a wide range of earthquake intensity levels. The relationship between the strength reduction factor and the ductility factor was then derived for all considered SDOF systems. The results show that the natural period of vibration as well as the primary concrete cracking can significantly influence on the predicted strength reduction factors. The incremental dynamic analysis was employed to calculate the system demand ductility in a wide range of earthquake intensity levels. The relationship between the strength reduction factor and the ductility factor was then derived for all considered SDOF systems. The results show that the natural period of vibration as well as the primary concrete cracking can significantly influence on the predicted strength reduction factors. The incremental dynamic analysis was employed to calculate the system demand ductility in a wide range of earthquake intensity levels. The relationship between the strength reduction factor and the ductility factor was then derived for all considered SDOF systems. The results show that the natural period of vibration as well as the primary concrete cracking can significantly influence on the predicted strength reduction factors.