Iranian Journal of Medical Physics
Volume:13 Issue: 2, Spring 2016

Recent studies of public underground parking lots showed the influence of radon concentration and the probable discomfort caused by parking cars.
Radon concentration was measured in semi-closed public parking lots in the six governorates of Kuwait, using Durridge RAD7radon detector (USA).
The peak radon concentration in the parking lots of Kuwait governorates was relatively higher during winter (63.15Bq/m3) compared to summer (41.73 Bq/m3). Radon in the evaluated parking lots revealed a mean annual absorbed dose (DRn: 0.02mSv/y) and annual effective dose (HE: 0.06mSv/y).
This study validated the influence of relative humidity and temperature as the major components of discomfort index (DI). The mean annual absorbed and effective dose of radon in the evaluated parking lots were found below the permissible limits. However, high radon DRn and HE were reported when the assessment included the parking lots, the surrounding residential apartments, and office premises. Furthermore, the time-series analysis indicated significant variations of the seasonal and site-wise distribution of radon concentrations in the indoor evaluated parking lots of the six Kuwait governorates

The concentration of substances, including urea, creatinine, and uric acid, can be used as an index to measure toxic uremic solutes in the blood during dialysis and interdialytic intervals. The on-line monitoring of toxin concentration allows for the clearance measurement of some low-molecular-weight solutes at any time during hemodialysis.The aim of this study was to determine the optimal wavelength for estimating the changes in urea, creatinine, and uric acid in dialysate, using ultraviolet (UV) spectroscopy.
In this study, nine uremic patients were investigated, using on-line spectrophotometry. The on-line absorption measurements (UV radiation) were performed with a spectrophotometer module, connected to the fluid outlet of the dialysis machine. Dialysate samples were obtained and analyzed, using standard biochemical methods. Optimal wavelengths for both creatinine and uric acid were selected by using a combination of genetic algorithms (GAs), i.e., GA-partial least squares (GA-PLS) and interval partial least squares (iPLS).
The Artifitial Neural Network (ANN) sensitivity analysis determined the wavelengths of the UV band most suitable for estimating the concentration of creatinine and uric acid. The two optimal wavelengths were 242 and 252 nm for creatinine and 295 and 298 nm for uric acid.
It can be concluded that the reduction ratio of creatinine and uric acid (dialysis efficiency) could be continuously monitored during hemodialysis by UV spectroscopy.Compared to the conventional method, which is particularly sensitive to the sampling technique and involves post-dialysis blood sampling, iterative measurements throughout the dialysis session can yield more reliable data.

Automatic human emotion recognition is one of the most interesting topics in the field of affective computing. However, development of a reliable approach with a reasonable recognition rate is a challenging task. The main objective of the present study was to propose a robust method for discrimination of emotional responses thorough examination of heart rate variability (HRV). In the present study, considering the non-stationary and non-linear characteristics of HRV, empirical mode decomposition technique was utilized as a feature extraction approach.
In order to induce the emotional states, images indicating four emotional states, i.e., happiness, peacefulness, sadness, and fearfulness were presented. Simultaneously, HRV was recorded in 47 college students. The signals were decomposed into some intrinsic mode functions (IMFs). For each IMF and different IMF combinations, 17 standard and non-linear parameters were extracted. Wilcoxon test was conducted to assess the difference between IMF parameters in different emotional states. Afterwards, a probabilistic neural network was used to classify the features into emotional classes.
Based on the findings, maximum classification rates were achieved when all IMFs were fed into the classifier. Under such circumstances, the proposed algorithm could discriminate the affective states with sensitivity, specificity, and correct classification rate of 99.01%, 100%, and 99.09%, respectively. In contrast, the lowest discrimination rates were attained by IMF1 frequency and its combinations.
The high performance of the present approach indicated that the proposed method is applicable for automatic emotion recognition.

Over the last decades, considerable levels of electromagnetic fields (EMFs) have been characterized in the living environment. Recent epidemiological studies on occupational and residential exposure to EMF have shown that 50/60 Hz fields, known as extremely low frequencies (ELF), have various biological effects, such as angiogenesis. This study aimed to investigate the effect of environmental 50 Hz magnetic fields at intensities of 3, 6, 15, 46, 110 and 207 mT on human umbilical vein endothelial cells (HUVECs) as a significant component of angiogenesis process.
In this study, 43 experimental groups were evaluated, including a control group, 6 sham exposure groups, 18 acute, and 18 chronic exposure groups with different exposure intensities and durations of exposure. Proliferation and viability of HUVECs were examined via cell counting and MTT methods, respectively.
No significant changes were observed in the proliferation of HUVECs by 50 Hz magnetic field, while the viability of some acute groups was found to increase. These findings confirmed the theory of "biological window" for magnetic fields.
According to the results of this study, since the 50 Hz magnetic field can effect on viability of HUVECs and these cells play a key role in angiogenesis, 50 Hz magnetic fields at the mentioned intensities probably could be effective in the improvement of angiogenesis process.

Natural and artificial radionuclides are the main sources of human radiation exposure, which enter the food chain from the environment. Radionuclides can affect human health by transferring from soil to plants and entering the human body. In this research study, we aimed to determine the activity concentrations of radionuclides and calculate the average annual committed effective dose (AACED) due to the ingestion of some medicinal and edible plants from Shazand, Markazi Province, Iran.
The specific activities of 226Ra, 232Th, 40K, and 137Cs in eight medicinal and edible plant species and their surrounding soils were determined, using gamma-ray spectrometry and a high-purity germanium (HPGe) detector. The samples were collected from Shazand, situated in Markazi Province, Iran.
The maximum soil-to-plant transfer factor (TF)for 226Ra, 232Th, 40K, and 137Cswas estimated at 0.13, 0.13, 3.17, and 0.09, respectively. Based on the findings, the AACED for 1kg of edible plants varied from 0.63±0.16 to 13.71±0.14μSv/y. The annual gonadal dose Equivalent (AGDE) varied from 556 to 717 µSv/y for the soil samples (mean: 642µSv/y). The threshold consumption rate for edible plants ranged between21.86and 82.63 kg/y.
In this study, AACED due to the ingestion of radionuclides was lower than the global average (0.3 mSv/y). Therefore, the present results indicated no radiation health risks, associated with the use of these medicinal plants for disease treatment. However, it should be noted that all soil samples and some plants were polluted by radiocesium.

According to the International Commission on Radiological Protection publication numbers 60 and 21, the environmental control standards should ensure human and other species protection to a desirable degree. Since application of radiographic procedures in Veterinary Medicine has increased significantly, in this study, we aimed to evaluate the entrance skin dose to the animals (e.g., dogs, cats, horses, and birds) undergoing diagnostic radiology.
The entrance skin dose to the animals in different radiology procedures were estimated through a) indirect estimation using the output of X-ray tubes and b) direct measurement using LiF:Mg, Ti (TLD-100) thermoluminescence dosimeter. Regression analysis was performed for comparison of the two methods. The animals included in this study were cats, dogs, small birds, horses, parrots, and chough.
The dose received by the animals varied from 20 mGy to 1189.2 mGy, depending on the animal thickness, focal spot to surface distance, imaging technique, and animal type.
Optimized procedures are suggested for obtaining high-quality images, with a reasonably low dose imposed to the animals.

Measuring magnetic induction phase shift (MIPS) changes as a function of cerebral hemorrhage volume has the potential for being a simple method for primary and non-contact detection of the occurrence and progress of cerebral hemorrhage. Our previous MIPS study showed that the intracranial pressure (ICP) was used as a contrast index and found the primary correlation between MIPS and ICP.
In this study，we theoretically deduced the approximate relationship between MIPS and ICP and carried out a comparison study between MIPS and ICP on cerebral hemorrhage in rabbits in this study. Acute cerebral hemorrhage was induced by injecting autologous blood (3 to 6mL) into the brain of rabbits in the experimental group (n=7).
The animal experiment results showed that the MIPS decreased significantly as a function of injection volume in the experimental group and the changes of ICP and MIPS of rabbits from experimental group presented a negative correlation. We also found that the MIPS slopes of all experimental samples had a change trend from fastness to slowness with a reverse of the change of ICP.
These observations suggested that the non-contact MIPS method might be valuable and potential for monitoring acute cerebral hemorrhage and obtaining the ICP information.

International Commission on Radiological Protection (ICRP) has provided a comprehensive discussion on threshold dose for radiation-induced cataract in ICRP publication 116. Accordingly, various parts of the eye lens have different radio-sensitivities. Recently, some studies have been performed to develop a realistic eye model with the aim of providing accurate estimation of fluence-to-dose conversion coefficients for different parts of the eye. However, the effect of accommodation, which changes the lens shape and pupil size, on dose conversion coefficients has not been considered yet. In this study, we purport to develop an accommodation-dependent eye model and to study the effects of accommodation on the electron and proton fluence-to-dose conversion coefficients.
Herein, a modified eye model was developed by considering the effects of accommodation on the lens shape and pupil size. In addition, MCNPX 2.6 Monte Carlo transport code was used to calculate the effects of eye lens accommodation on electron and proton fluence-to-dose conversion coefficients.
Calculation of dose conversion coefficients demonstrated that the accommodation causes up to 40% discrepancy for fluence-to-dose conversion coefficients of electrons in the range of 600 to 800 keV, which is due to the change of eye lens shape during the accommodation of the eye.
Since the accommodation of the eye change the lens shape and pupil size, it has considerable effect on fluence-to-dose conversion coefficients of electrons at some ranges of incident particle energies that should be considered in simulation. However, the fluctuation of dose conversion coefficients of protons is negligible.