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کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Iranian Journal of Medical Physics
- نوع مقاله: Journal Article
- کلمات کلیدی: N-acetylcysteine,Gamma-Irradiation,Radioprotective,Radiation Sickness
- چکیده:
- چکیده انگلیسی: Introduction It has long been known that ionizing radiation can lead to detrimental effects in normal cells. In this light, Radioprotective chemicals have been used to decrease morbidity or mortality caused by ionizing irradiation. This study aimed to evaluate the radio-protective effect of N-acetylcysteineagainst radiation-induced mortality in male mice. Materials and Methods 52 healthy male mice were divided into four groups including NAC before irradiation (1), irradiation (2), NAC after irradiation (3) NAC before irradiation (4) and control. Three groups were treated orally with 100 mg/ kg of NAC. Gamma irradiation was performed at 8 Gy using a Co-60 machine. Kaplan-Meier method and the log-rank test were performed, using SPSS version 16. The significance level was considered to be 0.05. Results The statistical analysis revealed a significant difference between the test and control groups (P<0.05). The percentage of survival after 30 days was 46.2% for the irradiation group (1). In addition, the percentage of decreased lifespan was calculated at 5.90%, 23.60% and 17.93% for the first-third groups, respectively. Conclusion Results revealed lack of effectiveness of treatment with NAC after lethal dose. These results suggested that application of NAC for mice before irradiation protected them from the lethal effects of whole-body irradiation.
- انتشار مقاله: 01-05-1395
- نویسندگان: Ashkan Salajegheh,Mehdi Hoseini,Mina Nouri,Rasool Dehghani Soltani,Yaser Masoumi-Ardakani
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Chemistry and Chemical Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: ring-opening polymerization,biocompatibility,Biodegradability,Pentablock copolymer,copolymerization
- چکیده:
- چکیده انگلیسی: In this work, new biodegradable ABCBA type pentablock copolymers with different mole ratio of L-lactide and PPDO-b-PEG-b-PPDO triblock copolymer were synthesized and characterized. In the first step, PPDO-b-PEG-b-PPDO triblock copolymer was synthesized via a ring-opening polymerization of P-DiOxanone (PDO) monomer with Poly (Ethylene Glycol) (PEG) using stannous octoate (Sn(Oct)2) as the catalyst. In the second step, L-lactide monomers (60 or 80 mole ratio) as the end blocks were added to the resulting prepolymer in presence of stannous octoate (Sn(Oct)2) catalyst. In the first step, Poly (Ethylene Glycol) (PEG) and, in the second step, triblock copolymer acts as the macro-initiator. The obtained pentablock copolymers were identified by 1H and 13CNMR spectroscopy. Intrinsic viscosity of the resulting copolymers was measured via dilute solution viscometry in chloroform as the solvent. The thermal properties (such as melting points, melting enthalpy and crystallinity) and thermal degradation behavior were studied by Differential Scanning Calorimetry (DSC) and Thermal Gravimetric Analysis (TGA). From the obtained results, it was seen that the poly (L-lactide) end blocks show similar crystallization behavior like poly (L-lactide) homopolymer and also melting temperature of pentablock copolymers rise with an increase in L-lactide content.
- انتشار مقاله: 09-10-1388
- نویسندگان: Jamshid Mohammadi-Rovshandeh,Majid Abdouss,Sayed Mehdi Hoseini,Mohammad Imani,Kamel Ekhlasi-Kazaj
- مشاهده
- جایگاه : پژوهشی
- مجله: Control and Optimization in Applied Mathematics
- نوع مقاله: Journal Article
- کلمات کلیدی: dynamical system,Linear programming,Discretization,Linear semi-infinite programming,Recurrent neural network
- چکیده: برنامهریزی خطی نیمه نامتناهی، دستهی مهمی از مسائل بهینهسازی است که بینهایت قید را شامل میشود. در این مقاله، برای حل این دسته مسائل، یک روش گسستهسازی با یک روش شبکه عصبی ترکیب شده است. با یک گسستهسازی ساده، مسئله برنامهریزی خطی نیمه نامتناهی به یک مسئله برنامهریزی خطی تبدیل شده است. سپس از یک مدل شبکه عصبی بازگشتی با یک ساختار ساده بر اساس یک سیستم دینامیکی، برای حل مسئله مورد استفاده قرار گرفته است. مسئله انتخاب پورت فولیو و چند مثال عددی دیگر برای نشان دادن کارآمدی مدل ارائه شده، مطرح گردیده است.
- چکیده انگلیسی: Linear semi-infinite programming problem is an important class of optimization problems which deals with infinite constraints. In this paper, to solve this problem, we combine a discretization method and a neural network method. By a simple discretization of the infinite constraints,we convert the linear semi-infinite programming problem into linear programming problem. Then, we use a recurrent neural network model, with a simple structure based on a dynamical system to solve this problem. The portfolio selection problem and some other numerical examples are solved to evaluate the effectiveness of the presented model.
- انتشار مقاله: 15-10-1392
- نویسندگان: Alaeddin Malek,Ghasem Ahmadi,Seyyed Mehdi Mirhoseini Alizamini
- مشاهده