نتایج جستجو برای: Proton

تعداد نتایج: 65826  

Asghar haddadi Tayebeh Akbarzadeh Yaser Kasesaz,

Introduction: Recently, an approach exploiting the proton therapy biological enhancement by using Boron atoms injected inside a tumor, has been proposed. Three alpha particles with an average energy around 4MeV are emitted from the point of reaction between a proton and boron. In addition, the 719 keV prompt gamma emitted by the proton Boron fusion reactions can be used for on-...

ژورنال: سنجش و ایمنی پرتو 2014

In this study, the MCNPX code version 2.6 has been used to simulate a proton therapy in thyroid gland. The neck phantom is cylindrical including skin, adipose, skeletal muscle and thyroid gland. Radiation source is close to the skin surface and single energy protons are collided perpendicular to the skin surface. The results of the simulation shows that the best proton energy interval, to cover...

Journal: :iranian journal of medical physics 0
alireza karimian department of biomedical engineering, faculty of engineering, university of isfahan, isfahan, iran.

introduction proton therapy is used to treat malignant tumors such as melanoma inside the eye. proton particles are adjusted according to various parameters such as tumor size and position and patient’s distance from the proton source. the purpose of this study was to assess absorbed doses in eyes and various tumors found in the area of sclera and choroid and the adjacent tissues in radiotherap...

Introduction: Many study shown the effectiveness dose enhancement with gold nanoparticles (GNPs), especially with low-energy x-rays. Recently, proton beam radiation therapy (PBRT) has attention as a treatment for tumors. The advantage in PBRT, which releases high dose at the controllable Bragg peak position that localized for Au target and the released dose increased in depth....

Dariush Sardari Mahdi Sadeghi, Niloofar Azadegan Seyed Pezhman Shirmardi,

Introduction: The proton beam produced in particle accelerators has an appropriate therapeutic potential. In this research, proton therapy of breast cancer is simulated using the MCNPX code in a MIRD phantom, also the contribution of scattered neutron dose during the proton therapy were calculated for the Heart, Lung and Liver.   Materials and Methods: For si...

Journal: :iranian journal of chemistry and chemical engineering (ijcce) 2000
ahmad shaabani faiezeh sadeghi nejadt issa yavari

: 1h nmr spectra of a series of enaminones r-co-ch=c(nhch2ph)-r  [1, r=ch3; 2, r=c6h5; 3, r=cf3; 4, r=ch2ch2ch2; 5, r=ch2c(ch3)2ch2], were obtained in the presence of trifluoroacetic acid in cdcl3 or dmso-d6 at 28 °c. steric, solvent, electronic and hydrogen bonding effects on the rates of acid-catalyzed nh proton exchanges were investigated. rate constants were calculated by 1h nmr line shape ...

Introduction: High-energy beams of protons offer significant advantages for the treatment of deepseated local tumors. Their physical depth-dose distribution in tissue is characterized by a small entrance dose and a distinct maximum -Bragg peak- near the end of range with a sharp fall-off at the distal edge. Alongside its advantages there are some point that they need to meticul...

In this study, proton conductive composite membranes were produced by using a poly(methylmethacrylate-co-maleic anhydride) (P(MMA-co-MAH)) copolymer and phosphotungstic Acid (PWA) as an additive of the proton conductive agent. P(MMA/MAH) 70/30, 50/50, and 30/70 were synthesized using a free radical polymerization reaction. PWA with a concentration of 2% was added to...

F. Maroufkhani, S.M.M. Abtahi, T. Kakavand,

Background: The present study aimed to investigate the equivalent dose in vital organs, including heart and lung, due to secondary particles produced during breast proton therapy. Materials and Methods: The numerical ORNL female-phantom was improved and simulated using the Monte Carlo MCNPX code. The depth-dose profile of proton beams with different energies was simulated. The proper energy ran...

Journal: :iranian journal of radiation research 0
y.j. go college of veterinary medicine, kyungpook national university, korea j.h. shin college of veterinary medicine, kyungpook national university, korea k.s. jeong college of veterinary medicine, kyungpook national university, korea s.j. park college of veterinary medicine, kyungpook national university, korea s.h. kim college of veterinary medicine, chonnam national university, korea s.y. ryu college of veterinary medicine, chungnam national university, korea

background: the purpose of this paper is to establish an easy and reliable biodosimeter protocol to evaluate the biological effects of proton beams. materials and methods: human peripheral blood lymphocytes were irradiated using proton beams (let: 34.6 kev μm−1), and the chromosome aberrations induced were analyzed using cytokinesis-blocked (cb) micronucleus (mn) assay. to determine the efficie...

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