حسینی, سید محمد امین

دانشگاه علوم پزشکی شیراز، شیراز، ایران

[ 1 ] - مروری بر تکنیک هادرون درمانی

Despite major progress in radiotherapy, exponential attenuation of initial photons due to the nature of their interaction with matter has remained as the most important challenge. Photons have no well-defined range and their doses are reduced exponentially. Therefore, tissues located before and after the tumors receive a significant dose. Today, new techniques based on proton and carbon charged...

[ 2 ] - A Monte Carlo Study on the Shielding Properties of a Novel Polyvinyl Alcohol (PVA)/WO3 Composite, Against Gamma Rays, Using the MCNPX Code

Background: In recent years, there has been an increased interest toward non-lead radiation shields consisting of small-sized filler particles doped into polymer matrices. In this paper, we study a new polyvinyl alcohol (PVA)/WO3 composite in the presence of high-energy gamma photons through simulation via the Monte Carlo N-Particle (MCNP) simulation code. Materia...

[ 3 ] - Blocking Short-Wavelength Component of the Visible Light Emitted by Smartphones’ Screens Improves Human Sleep Quality

Background: It has been shown that short-wavelength blue component of the visible light spectrum can alter the circadian rhythm and suppress the level of melatonin hormone. The short-wavelength light emitted by smartphones’ screens can affect the sleep quality of the people who use these devices at night through suppression of melatonin.Objectives: In this study, we examined the effects of co...

[ 4 ] - Does Exposure to Static Magnetic Fields Generated by Magnetic Resonance Imaging Scanners Raise Safety Problems for Personnel?

MRI workers are occupationally exposed to static and time-varying gradient magnetic fields.  While the 24-hour time-averaged exposure to static magnetic fields is about a few mT, the maximum static field strength can be as high as 500 mT during patient setup. Over the past several years, our laboratory has performed extensive experiments on the health effects of exposure of animal models and h...

[ 5 ] - Analysis of Relative Biological Effectiveness of Proton Beams and Iso-effective Dose Profiles Using Geant4

Background: The assessment of RBE quantity in the treatment of cancer tumors with proton beams in treatment planning systems (TPS) is of high significance. Given the significance of the issue and the studies conducted in the literature, this quantity is fixed and is taken as equal to 1.1.Objective: The main objective of this study was to assess RBE quantity of proton beams and their variations ...