Amirkabir Technical University

Tehrān, Iran

Amirkabir Technical University

Tehrān, Iran
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Moghaddam L.,Amirkabir Technical University | Jalilian A.,Nuclear Science and Technology Research Institute, Iran
Medical Physics | Year: 2011

Purpose: Developing monoclonal antibodies with beta‐emitters has led to the introduction of important agents in radioimmunotherapy. In this work, Sc‐46 chloride was obtained by thermal neutron flux (4 × 1013 n.cm‐2.s‐1) of natural metallic scandium sample followed by dissolution in acidic media (radiochemical purity ITLC, >99%) as a substitute for 47Sc in radiolabeling studies. Methods: 46Sc was produced with a specific activity of approximately 7.0–7.5 mCi/mg and radionuclidic purity of >98% by irradiation. NHS DOTA was freshly prepared and kept under a blanket of dry N2. Rituximab (MabThera) was used without further purification. Whatman No. 1 paper was obtained from Whatman (Maidstone, UK) for instant thin layer chromatography (ITLC). Radio‐chromatography was performed by using a bioscan AR‐2000 radio TLC scanner instrument (Bioscan). A high purity germanium (HPGe) detector coupled with a Canberra™ (model GC1020‐7500SL) multichannel analyzer and a dose calibrator ISOMED 1010 were used for counting distributed activity in rat organs. Results: The liver is the major target organ due to the presence of metaloproteins, apart from the liver, the spleen is the second major accumuation target.Thus, transferrin is principally responsible for scandium metabolism in vivo, while binding with ferritin is negligible []. Slight differences in the reported biodistribution data and the present work are possibly because of using rats instead of mice. Conclusions: As an immunoconjugate model, rituximab was conjugated with DOTA chelating agent, followed by 46Sc‐radiolabeling. The biodistributions of radiopharmaceutically acceptable 46ScCl3 and 46Sc‐DOTA‐rituximab formulations were checked in wild‐type rats up to 72 hours post injection. The biodistribution of 46ScCl3 among the tissues were in agreement with the former reports, while 46Sc‐DOTA‐rituximab accumulated mostly in the liver and spleen as shown in many other radiolabeled anti‐CD20 immunoconjugates. The development of other 47Sc‐labeled‐monoclonal antibodies for ultimate radioimmunotherapy based on this study using long‐half life, 46Sc radionuclide is possible. © 2011, American Association of Physicists in Medicine. All rights reserved.


Moghaddam L.,Amirkabir Technical University | Setayeshi S.,Amirkabir Technical University
Medical Physics | Year: 2011

Purpose: To improve the dose distribution for Gamma‐Knife4C. The final collimators of beam in Gamma knife are located in Helmet and consist of 4 sizes in 4mm, 8mm, 14mm and 18mm. The physician uses one of these sizes individually depend on treatment plan and the location of isocenter in tumor. In this project the improvement of treatment plan suggested by using the four sizes Helmet collimator together simultaneously. We developed a procedure to arrange the collimators in helmet to get optimum dose in tumor. Methods: To achievement this goal, ANN (Artificial Neural Network) is used. The procedure consists of nonlinear program together with Artificial Neural Network (ANN) to predict the best design of collimators in helmet and the location of shots. Using different sizes of collimators change the ellipsoidal shape of shots to a non uniformed shape which can be flexible to the location of shots. ANN predicts the best arrangement of collimators in helmet. To design ANN, data for training, was obtained by Monte Carlo Simulation (MCNP 4C). Results: To test the Network, different dose of iso‐centre and also neighbor pixels were considered as input to the network and the arrangements of collimators in helmet were obtained from it. The answers were checked by MCNP 4C simulation by calculating the dose in the assumed area and comparing with the desired values which were considered as input to the network. We got the mean square error between 0.0008 and 0.01. Conclusions: By using this method, dose distribution in tumor has better coverage. The shape of each shot can be considered not only sphere but also other shapes to cover tumor especially in target boundaries. This capability could improve the treatment plan to reduce the number of shots along with optimum dose. © 2011, American Association of Physicists in Medicine. All rights reserved.


Safari E.,Queen's University | Jalili Ghazizade M.,University of Tehran | Shokouh A.,Amirkabir Technical University | Nabi Bidhendi Gh.R.,University of Tehran
International Journal of Environmental Research | Year: 2011

High strength fresh leachates generated at a new disposal trench, compost plant and partially stabilized leachate of an older trench were characterized in terms of anaerobic degradation at laboratory batch scale at 35 °C. Fresh leachate had extremely high COD of 66,710 - 89,501 mg/L along with low pH of 4.1 -5.9 in contrast to older and therefore partially stabilized leachate with a COD of about 19,000 mg/L and higher pH of 8.4. Filtration of fresh leachate samples showed to have considerable effect on continuation of degradation as for the unfiltered samples, degradation nearly stopped after a slight reduction in COD. As a first attempt, it was shown that a considerably better fit was achieved for COD variations of filtered fresh leachate samples using first order multistage kinetic model based on which hydrolysis was found to have the smallest rate, therefore being the rate limiting stage in anaerobic degradation process.


Shojafar M.,University of Rome La Sapienza | Pooranian Z.,Islamic Azad University at Dezful | Meybodi M.R.,Amirkabir Technical University | Singhal M.,University of California at Merced
Journal of Intelligent Manufacturing | Year: 2015

Cost and execution time are important issues in economic grids, which are widely used for parallel computing. This paper proposes ALATO, an intelligent algorithm based on learning automata and adaptive stochastic Petri nets (ASPNs) that optimizes the execution time for tasks in economic grids. ASPNs are based on learning automata that predict their next state based on current information and the previous state and use feedback from the environment to update their state. The environmental reactions are extremely helpful for teaching Petri nets in dynamic environments. We use SPNP software to model ASPNs and evaluate execution time and costs for 200 tasks with different parameters based on World Wide Grid standard resources. ALATO performs better than all other heuristic methods in reducing execution time for these tasks. © 2013, Springer Science+Business Media New York.


Salek N.,AmirKabir Technical University | Jamre M.,AmirKabir Technical University | Moghaddam B. L.,Nuclear Science and Technology Research Institute, Iran | Jalilian A.R.,Nuclear Science and Technology Research Institute, Iran | Shamsaee M.,AmirKabir Technical University
Annals of Nuclear Energy | Year: 2012

This manuscript describes an investigation on the production of 191Os/ 191mIr by Tehran Research Reactor (TRR). 191Os-hexachloro-osmate was obtained by thermal neutron (4 × 10 13 cm -2 s -1) irradiation of enriched 190Os sample followed by fusion with KOH and KNO 3 in acidic media. One of the important radionuclide impurities is 192Ir that is produced during irradiation in reactor. Separation this impurity from 191Os is developed by a new approach in this research and the total recovery yield of 191Os is about 99% and the total time required for completion the procedure is about 30 min. This method improved the yield and the time of performance in comparison with values published in literature. 191Os is loaded on an anion-exchange column and 191mIr eluted with normal saline. Each elution is 1 ml of 0.9% saline at pH 6.5-7. The yield of generator was assessed for 2 weeks. 191mIr yield is 15-18% and 191Os breakthrough is about 2 × 10 -4-2 × 10 -3. © 2011 Elsevier Ltd. All rights reserved.

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