International Journal of Radiation Research
Year:2015 | Volume:13 | Issue:4|Papers Count:14

Background: Monte Carlo simulaons play a vital role in the calculaon of the necessary shielding both for neutrons and photons. Advanced and simple shielding materials against neutron and gamma rays were compared by simulaon using the MCNB4B Monte Carlo code. The simulaons were carried out for the three common neutron sources, namely the252Cf, the 241Am/Be and the DD neutron generator which are suitable for transportable facilies.Materials and Methods: The source has been simulated as sphere with 3 cm diameter while the necessary shielding is designed in the form of a sphere around the neutron source. The materials considered were chosen according to the EU Direcve 2002/95/EC, hence excluding lead and cadmium.Results: In the case of DD neutron generator the thickness, the weight and the volume of the shield can decrease up to 41.3, 44, and 78.4% correspondingly. With regard to the 252Cf neutron source the use of advanced shielding materials can reduce the corresponding parameters up to 32.7, 40.7, and 68.4% respecvely. As regards the 241Am/Be neutron source, based on advanced shielding materials the thickness, the mass and the volume of the shield can decrease by 33.8, 49.5, and 70% respecvely.Conclusion: The obtained results showed that the use of advanced shielding materials has led to reduce greatly the weight and the volume of the necessary shield.

Background: Our purpose was to investigate propolis and its component caffeic acid phenethyl ester (CAPE) for their antioxidant effects on the brain tissue of rats exposed to ionizing radiation (IR).Materials and Methods: Fi& y-four male albino Sprague-Dawley rats, divided into six groups, were designed as normal control group, cranial irradiation of 5 Gray alone, irradiation plus CAPE, irradiation plus propolis, control groups of propolis and CAPE. Oxidative/antioxidative status indicators, lipid peroxidation and an oxidant enzymes, were determined by biochemical methods in homogenized brain tissue of rats.Results: Malondialdehyde level, the lipid peroxidation index, in the irradiation alone group was found to be significantly increased compared to all of the other groups (p<0.001). Enzyme activities of superoxide dismutase (SOD) were 504.93, 720.70 and 659.98 for irradiation alone group, irradiation plus CAPE group and irradiation plus propolis group, respectively. Enzyme activity of SOD in the irradiation alone group was found to be significantly decreased compared to the groups received propolis or CAPE (p<0.003). Enzyme activity of glutathione peroxidase was not found statistically different among all of the groups.Conclusion: Propolis and CAPE were found to be beneficial agents in protecting brain tissue against IR-induced oxidative damage.

The development of nanotechnology has been a boon to mankind as its significance paved the way for several applications in therapeutics. This study was to evaluate the an ti-arthritic capability of nano Selenium-lovastatin mixture (Lov-Se) against inflammatory cascade in arthritic irradiated rats.Materials and Methods: Animal model of Arthritis was organized by subcutaneous injection of Complete Freund’s adjuvant; CFA. Rats were exposed to g-radiation (2Gy every 3 days up to total dose of 8 Gy). Lov-Se (1ml ≈20 mg kg−1 day-1 Lov and 0.1 mg kg−1 day−1 Se) was administrated by daily oral injection. The an tioxidant parameters (heart glutathione peroxides; GSH-Px, catalase; CAT, superoxide dismutase; SOD, xanthine dehydrogenase; XDH, reduced glutathione; GSH and blood selenium; Se), oxidant markers (heart Xanthine oxidase; XO, Nitric oxide; NO, protein carbonyls and thiobarbituric acid reactive substances; TBARS) and the inflammatory molecules (serum tumor necrosis factor-alpha TNF-a, C-reactive protein; CRP and rheumatoid factor; RF) were determined.Results: The arthritic and arthritic irradiated rats were displayed augment oxidative stress, inflammatory cascade and impaired anoxidant status compared to control.Conclusion: The data revealed that Lov-Se administration ameliorate oxidative, antioxidants parameters as well as inflammatory factors. The prolonged administration of Lov-Se mixture in appropriate concentration could exert a considerable systemic anti-inflammatory action through adjustment of red-ox tone and the integration of XDH/XO ratio.

Background: The aim of the study was to compare the radioprotective efficacy in the kidney of L-carnitine to that of amifostine.Materials and Methods: Thirty three-month-old Wistar albino rats were randomly assigned to four groups: Group 1 (Control); Group 2 (Irradiation alone); Group 3 (amifostine plus irradiation); and Group 4 (L-carnitine before irradiation). The rats in Groups 2, 3, and 4 were irradiated individually with a single dose of 20 Gy to whole abdomen. L-carnitine (300 mg/kg) or amifostine (200 mg/kg) was administered 30 minutes before irradiation. Euthanasia was performed 5 days a/er irradiation, and kidneys were evaluated histopathologically.Results: Dilatation of Bowman’s capsule, congeson of blood vessels, and tubular epithelial degeneraon were significantly different among the groups (p<0.05). Pretreatment with both L-carnitine and amifostine reduced the radiation-induced dilatation of Bowman’s capsule (p<0.05), congeson of blood vessels (p<0.05), and tubular epithelial degeneration (p<0.05).L-carnitine and amifostine were similar in protective effect.Conclusion: L-carnitine was equally effective as amifostine in protecting the kidney against acute irradiation damage.

Background: After breast conserving surgery, most recurrences occur around the primary tumor site. This justifies the use of boost radiotherapy to the primary site of tumor. Surgical scar is not always a good surrogate for the location of the lumpectomy cavity. The aim of this study was to evaluate ultrasonic guidance for detection of the lumpectomy cavity after breast conserving surgery for electron beam boost field planning.Materials and Methods: 35 breast cancer patients who treated with whole breast irradiation after breast conserving surgery underwent ultrasonic evaluation for measurement of depth and size of lumpectomy cavity. Results of ultrasonic imaging were used to define electron boost field size and depth of treatment.These results were compared with clinical measurements that made by two expert radiation oncologists.Results: The operative bed was well visualized in all of the patients. In only 21 patients (60%) cavity was located on the scar.Depth determined by ultrasonography was not significantly correlated with depth determined by clinical impression (r=0.304, P<0.01). This means that the results of the two methods are quite different (these results are also true for other variables). In 88% of patients, the depth of treatment and electron beam energy that were selected by clinical measurements were changed.Conclusion: Ultrasound is found useful tool for measurement of depth and size of lumpectomy cavity and could be used for boost planning. It is easily available, non-invasive and inexpensive.

Background: Cell viability is an important factor in radiation therapy and thus is a method to quantify the effect of the therapy.Materials and Methods: The viability of human hepatoma (HepG2) cells exposed to radiation was evaluated by both the MTT and Trypan blue assays. The cells were seeded on 96 well-plates at a density of 1 x 104 cells/well, incubated overnight, and irradiated with 1-100 Gy.Results: The cell viability was decreased in a dose- and me- dependent manner when using the Trypan blue assay, but no significant changes in the response to dose could be detected using the MTT assay. It indicated that the MTT assay was not efficient at a cell density of 1 x 104 cells/well on 96 well-plates to determine cell viability. Subsequently, the relationship between cell viability and lower cell density (1 x 103, 3 x 103, and 5 x 103 cells/well) was investigated. A cell density of 1 x 103 was found to be the most effective when using the MTT assay. Results show that the cell density is most important when using the MTT assay in 96 well-plates to follow in radiation effects. Furthermore, the radiation-induced cell viability dependent on cell density was confirmed by using the traditional Clonogenic assay.Conclusion: Our results suggest that the MTT and Trypan blue assays are rapid methods to detect radiation-induced cell viability of HepG2 cells in about 3 days as compared with 14 days of assay time in the Clonogenic assay.To obtain accurate cell viability measures using both rapid assays, an incubation me of at least 3 days is needed a6er irradiation.

Background: Widespread and growing sources of electromagnetic radiation raised concerns attributed to the potential adverse health risk of radiofrequency fields. Given the functional importance of the hippocampus, this study aimed to investigate the effects of electromagnetic waves radiated by mobile jammer on hippocampal expression of p21 and p53 genes as regulators of cellular apoptosis.Materials and Methods: Forty-eight male BALB/c mice were randomly divided into six groups (n=8 each). Animals in the experimental groups were radiated at the frequencies of 900 and 1800 megahertz for a period of 30 consecutive days, while the control group remains constant during the experiment. The hippocampal expression of p21and p53 mRNAs were evaluated using Real-Time PCR.Results: There were not differences between the mean expression level of p53 and p21 genes of the exposure groups compared to those of the control group (P>0.05). The ratio expression of p53 and p21 genes was increased to greater than one (p53/p21>1) in almost all experimental groups compared to controls.However, there was not significant differences between the expression level of p53 and p21 genes among the experimental groups using paired t test (p>0.05).Conclusion: Taken together, our findings demonstrate changes in hippocampal expression level of p53 and p21 a; after mobile jammer radiation.However, cell condition expected to remain relatively stable over the exposure period due to parallel changes of both pro- and anti- apoptotic genes at the same time.

Background: Accurate dose calculations in small beamlets and lung material have been a great challenge for most of treatment planning systems (TPS). In the current study, the dose calculaon accuracy of TiGRT TPS was evaluated for small beamlets in water and lung phantom by comparison to Monte Carlo (MC) calculations.Materials and Methods: The head of Siemens Oncor-impression linac was simulated for 6 and 18 MV photon beams using MCNPX MC Code. The model was validated using measured percentage depth dose and beam profiles. Then, the validated model used for dose calculations for small beam lets in water as well as lung phantoms. For treatment planning purposes, the lung phantom was scanned and imported into the TPS, and then the percentage depth dose values were obtained from plans for small fields of 1×1, 2×2, 3×3 and 4×4 cm2 in water and lung phantom.Results: For small fields in water phantom, there was a good agreement between TPS and MC for 2×2 to 4×4 cm2 field sizes. Nevertheless, the depth doses in lung phantom showed large discrepancies between TPS and MC calculations for points inside lung and lung-so4 tissue interfaces. The TPS underesmated the lung dose up to 67% and 110% for 6 and 18 MV beams compared to MC results.Conclusion: Our findings revealed that the TiGRT TPS was not able to account for lung inhomogeies in small beamlets. Besides, the TPS calculated depth doses were not accurate enough to be used for small beamlets used in IMRT of lung region.

Background: Natural radionuclides are always present in the environment.Human exposure to the background radiation is inevitable. It is therefore important to assess health risk associated with these radionuclides.Materials and Methods: The distribution of natural radionuclides 238U, 232Th and 40K in soil samples collected from all the twenty (20) local Governments headquarter areas in Ogun state, Nigeria were determined by gamma spectroscopy using a high-purity germanium detector. The measured concentrations were used in estimating the radiological risk pose to people living in these communities.Results: The activity concentrations measured ranged between 3 ± 1 Bqkg-1 (O0a) to 27 ± 6 Bqkg-1 (odeda) for 238U, 10 ± 1 Bqkg-1 (O0a) to 126 ± 6 Bqkg-1 (Ijebu Igbo) for 232Th and 7 ± 6 Bqkg-1 (Aiyetoro) to 497 ± 1 Bqkg-1 (Odeda) for 40K. The mean radium equivalent calculated was 77.6 Bqkg-1 which is lower than 370 Bqkg-1 of the world average and the hazard indices calculated were lower than unity.Conclusion: The absorbed rate and annual effective dose estimated for most of the locations are in good agreement with world average values except for Akomoje, Ake-Abeokuta, Ogere, Ijebu-Igbo and Odeda.

Background: Wi-Fi allows electronic devices such as laptops to exchange data or connect to a network resource. The main goal of this study was to assess the bioeffects of short term exposure to 2.4 GHz microwave radiation emitted from a common Wi-Fi router on sperm quality.Materials and Methods: Male Wistar rats were divided into 7 groups; I, sham exposed 4 h/ day for 7days at 30 cm from the router. II, exposed for 2 h/day for 7days at 30 cm and sacrificed a0er 53 days. The exposure protocols for groups III to VII were 2h – 30 cm, 2h – 60 cm, 4 h – 30 cm, 4 h- 60 cm, 4 h – 30 cm (no data exchange) respectively. Rats in all the groups except group II, were sacrificed immediately a0er exposure and basic parameters of testicles weight, sperm motility, morphology, count, and DNA fragmentation were studied. Nonparametric tests were used to detect statistically significant differences between different groups.Results: Findings of this study showed statistically significant differences between the relative frequency of progressive and rapid progressive sperms in sham exposed rats compared to those of exposure groups. The testicles weight, DNA fragmentation of sperms and the frequency of sperms with normal morphology were not affected by Wi-Fi radiation. However, statistically significant differences between sperm count of the sham exposed rats compared to those of exposure group were observed.Conclusion: Exposure to microwave radiation emitted from Wi-Fi routers affects sperm parameters such as count and motility which are among the key parameters determining the chance of conceiving.

Background: In this study are submitted the radon concentration measurement results of four underground mines: Stanterg, Artana, Hajvali and Badovc, which are owned by Trepca Enterprise, Kosovo. The mines have the same geological formaon and from these mines are extracted ores rich with lead, zinc, silver, and gold. The radiation exposures caused by radon and radon daughters was determined and gamma dose measurements were also performed in the same time.Materials and Methods: The measurement of radon concentrations in the environment of mines is carried out by CRM 510, a portable device which continuously made measurement for four consecutive days. The gamma exposure was determined using fully portable handheld instrument GR-130 Exploranium.The detector consisted of a 65 cm3 sodium iodide NaI (Tl) and a GM tube. The system was calibrated against a137Cs standard and checked for stability using a low-activity 9 kBq radioactive source.Results: The radon gas concentration for underground mines under study varied from minimal values 60 Bqm-3 to maximal recorded value 748 Bqm-3. The average radon concentration for mines Stanterg, Artana, Hajvali and Badovc are 301.6, 191.4, 463.2 and 527.2 Bqm-3, respectively.Conclusion: The average of total annual effective doses from radon concentration and radon decay products for miners under the study is 2.67 mSv and just from gamma ray exposure is 0.26 mSv. The average values for radon concentration and radon decay products to mines under the study are lower than acon level 1000 Bq m-3 given by IAEA.

Background: Dosimetry is a fundamental part of the radiation processing industry. Aqueous inorganic dosimeters have been used for gamma radiation dosimetry such as standard ferrous sulfate dosimeter. The purpose of this study was to investigate the effect of gamma radiation on the diethyl fumarate DEF in dimethyl sulfoxide DMSO solution and its possible use in chemical dosimetry.Materials and Methods: Three solutions having different concentrations of DEF were prepared (5, 10 and 20%) and exposed to various gamma doses. Irradiation was carried out using ROBO facility of60Co gamma ray. Absorbance was measured using Melton Roy 1201 UV-VIS spectrophotometer.Results: The absorption spectra of irradiated solution showed broad absorption bands between (325-400nm) with a shoulder at 332 nm. The absorbance increased with increasing the dose. Good response and linear relationship were found between absorbed dose and absorbance of 10% and 20% DEF concentration in the range of 0-225 kGy at the measured wavelength. Good dose rate independence was observed in the range of 14-33 kGy/h. It was noced that irradiated samples had a good stability in darkness. Whereas, the response was affected during the storage in day light.This response was found to be depended on the irradiation temperature within the range of 18- 520C.Conclusion: Our measurements showed that the ability of using the solution of diethyl fumarate DEF in dimethyl sulfoxide DMSO as a high dose radiation dosimetry. The useful dose range for 10% and 20% DEF of concentrations is up to 225 kGy. Nevertheless, the correction of temperature for routine dosimetry measurements should be taken into account.

Background: Radiation therapy uses high-energy radiation to kill cancer cells.Photoneutron contamination and induced radioactivity of high energy therapeutic photon beams are considered as the main source of occupational exposure to radiation therapists who works with linear accelerators operating above 10 MV.Materials and Methods: The gamma dose rates were measured after termination of different treatment approaches using 15 MV photons and room entry times for each approach was determined. Based on the results of this study, the annual dose of radiation therapists was estimated.Results: The highest dose rate that measured in the treatment room was belonged to 3-field pelvic approach which was equal to 5 ± 1.1 mSv/h. The radiation therapist's room entry times were determined between 3 to 10 minutes and the annual dose was estimated up to 5.9 mSv/y.Conclusion: Although the estimated annual dose is less than the internationally permi2ed value, the undesirable dose to radiation workers could be reduced through considering recommended room entry times.

According to the report published by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) in 2000, Ramsar city in northern Iran, has some inhabited areas with the highest known natural background radiation levels in the world...