Discrete time random walks, in which a step of random sign but constant length δx is performed after each time interval δt, are widely used models for stochastic processes. In the case of a correlated random walk, the next step has the same sign as the previous one with a probability q 6= 1 2 . We extend this model to an inhomogeneous ensemble of random walkers with a given distribution of pers...

We read the article entitled ‘‘The effect of esmolol on corrected-QT interval, corrected-QT interval dispersion changes seen during anesthesia induction in hypertensive patients taking an angiotensin-converting enzyme inhibitor’’ by Ceker et al. with interest.1 The authors investigated the effects of esmolol on the hemodynamic, correctedQT (QTc) interval and corrected-QT interval dispersion (QT...

the purpose of the research was determine the effects of gamma ray on seed germination, seedling height and root length of rice (oryza sativa l. spp. indica cv. mr219) to identify the lethal dosage of the radiation. paddy seeds of mr219 were exposed to different doses of gamma radiations viz 50,100,150,200,250,300,350,400,450,500,600,700,800,900 and 1000 gy using 60co as the radiation source. t...

introduction: midazolam has turned into a common drug for pediatric procedural sedation and analgesia. however, there is not much data regarding its proper dose and potential side effects in the iranian children population. therefore, the present study was done to compare 2 doses of iv midazolam in this regard. methods:  the present clinical trial was performed to compare 0.1 and 0.3 mg/kg dose...

background: the most efficient application of ionizing radiation is serving medical purposes and using this radiation has caused people to learn that artificial sources of radiation exposure among these resources can be of highest exposure rate.   objective: the present study is aimed at initially establishing a baseline for local-reference dose level in mazandaran, iran in 12 projections of th...

background: monte carlo (mc) modeling of a linear accelerator is a prerequisite for monte carlo dose calculations in external beam radiotherapy. in this study, a simple and efficient model was developed for elekta sl-25 linear accelerator using mcnp4c monte carlo code materials and methods: the head of elekta sl-25 linac was simulated for 6 and 18 mv photon beams using mcnp4c mc code. energy sp...

abstractbackground: there are relatively rich uranium mines in regions of saghand and bafgh in yazd province. this survey was carried out to provide a map of ambient gamma radiation of yazd province and the probable effects of the existence of these mines on background radiation dose rates.materials and methods: the measurements of the outdoor and indoor–environmental exposures (including cosmi...

background: monte carlo determination of tg-43 brachytherapy dosimetry parameters and dose distribution calculation for 131cs source model cs-1 are presented in this study. materials and methods: the dose distribution was calculated around the 131cs model cs-1 located in the center of 30 cm ×30 cm ×30 cm water, and soft tissue phantoms cube using mcnp code by monte carlo method. the percentage ...

background: natural radioactivity in materials under certain conditions can reach the hazardous radiological levels. so, it becomes necessary to study the natural radioactivity in different materials to assess the dose for the population in order to know the health risks and to have a baseline for future changes in the environmental radioactivity due to human activities. materials and methods: ...

background: polymer gel dosimetry is still the only dosimetry method for direct measuring of threedimensional dose distributions. mri polymer gel dosimeters are tissue equivalent and can act as a phantom material. in this study the obtained isodose maps with pagat polymer gel dosimeter were compared to those calculated with egsnrs for singleshot irradiations of 8 and 18 mm collimators of gamma ...