• Asian Pacific Journal of Cancer Prevention
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• v.13 no.8
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• pp.4101-4105
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• 2012

Purpose: The degree of radiation injury to kidneys which are located within the limits of radiotherapy area is determined by the volume and the dose of radiation to which the organ is exposed. When the tolerance dose of the kidney is exceeded after a latent period of 6 months acute nephritis develops and after 18 months chronic nephritis ensues. Melatonin is known to prevent the oxidative injury of toxins and radiotherapy with its free radical scavenging capacity. Methods and Materials: In this study 8 weeks old 24 Sprague -Dawley rats were allocated into 4 groups: Control group; Radiotherapy group (20 Gy bilaterally in 5 fractions); Melatonin group (10 mg/kg intraperitoneally), and Melatonin+radiotherapy group (20 Gy Radiotherapy in 5 fractions+ melatonin 10 mg/kg intraperitoneally). After a follow-up period of 6 months BUN was determined in all groups. After rats were euthanized the kidneys were removed for histopathological examination under both light and electron microscopes. Results: After 6 months follow-up, both at light and electron microscopy levels, the rats in radiotherapy+melatonin group were significantly protected against the radiation injury comparing to radiotherapy group (p<0.05). Conclusion: It was shown in this experimental model that melatonin has protective effects against radiation injury to kidneys.

• Journal of Radiation Industry
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• v.4 no.4
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• pp.325-334
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• 2010

Transcriptional regulation in response to salt in mutant lines was investigated using oligonucleotide microarrays. In order to characterize the salt-responsive genes in rice, the expression profiles of transcripts that responded to salt-treatment were monitored using the microarrays. In the microarray analysis, among 37,299 reliable genes, 5,101, 2,758 and 2,277 genes were up-regulated by more than 2-fold using the salt treatment, while the numbers of down-regulated genes were 4,619, 3,234, and 1,878 in the WT, ST-495, and ST-532, respectively. From genotype changes induced by gamma ray mutagenesis, 3,345 and 2,397 genes were up-regulated, while 2,745 and 2,075 genes were down-regulated more than 2-fold in the two untreated mutants lines compared with untreated WT, respectively. A total of 3,108 and 2,731 genes were up-regulated more than 2-fold, while 3,987 and 3,660 genes were down-regulated by more than 2-fold in the salt treatment of the two mutants lines compared with the salt treated WT, respectively. The expressions of membrane transporter genes such as OsAKT1, OsKUP, and OsNAC increased more severely in ST-495 and ST-532 than in the WT. The expressions of the proline accumulation related genes such as OsP5CS and OsP5CR were also markedly increased in the salt tolerant mutants when compared to the WT plant.

• Journal of radiological science and technology
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• v.46 no.1
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• pp.9-14
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• 2023

When measuring cerebrovascular with 3D rotational angiography, the accuracy was verified by comparing the actual size and measurement size, respectively. It is intended to help select therapeutic materials and instruments during cerebrovascular intervention by comparing the average error rates for measured values in the 3DRA and CTA methods by examining with protocols such as brain CTA, which are always performed in emergency situations. The mean error rate between the groups of measurers was ±3.655% for radiation technologist and ±3.331% for university students, and the mean error rate of the student group was within tolerance (±10%), and the independent sample T-test result t =0.879, p=0.394 (p>0.05) showed no statistically difference between the two. In addition, the average error rate measured by both groups by 3DRA was measured below ±5% within the tolerance error rate (±10%), and most of CTA was measured within the tolerance range (±10%), but showed an average error rate of up to 5.65%, and the independent sample T-test result was statistically more accurate than 3DRA. Both the 3DRA method and the brain CTA method for measuring cerebrovascular size could be accurately measured within tolerance, but it would be better to measure cerebrovascular blood vessels using a more accurate 3DRA method during cerebrovascular intervention.

• Corrosion Science and Technology
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• v.8 no.2
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• pp.68-73
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• 2009

An evaluation of underwater - repair coating materials was based on the premise that defective areas of the existent epoxy coating such as blistering and cracking will be repaired on spot under submerged condition. Tests include the clarification as to whether they are compatible between as-built coating and new repair coating on each concrete specimen. Candidate coating materials for repair were tested in a laboratory to scrutinize their suitability to perform the needed function satisfactorily. The qualification tests performed are as a minimum as follows: Integrated radiation tolerance test, chemical resistance test (submerged condition in deionized water), hardness test and adhesion test of the repair materials. The proper repair coating materials were selected and approved from this test results.

• Journal of the Korea Institute of Military Science and Technology
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• v.11 no.6
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• pp.74-80
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• 2008

Analysis of the electromagnetic environment on topside of a ship is needed for optimal arrangement of all kinds of antennas to be installed on the shipboard in order to minimize the probability of EMI of equipment and subsystems in real ship after construction phase. In this paper we analyze the characteristics of electric-fields such as radiation patterns and near E-fields of V/UHF antennas installed on a shipboard. We compare simulated results with measurements on the real ship for near E-fields to verify the reliability of the computed electromagnetic environment. Although there are various factors causing errors such as cable loss and impedance mismatching etc. when measuring near E-field, both data show similar trends in the range of the acceptable tolerance.

• Journal of Astronomy and Space Sciences
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• v.33 no.3
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• pp.229-236
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• 2016

We present proton-induced single event effects (SEEs) and γ-ray-induced total ionizing dose (TID) data for 1 Gbit lowpower double data rate synchronous dynamic random access memory (LPDDR SDRAM) fabricated on a 5 μm epitaxial layer (54 nm complementary metal-oxide-semiconductor (CMOS) technology). We compare our radiation tolerance data for LPDDR SDRAM with those of general DDR SDRAM. The data confirms that our devices under test (DUTs) are potential candidates for space flight applications.

• Nuclear Engineering and Technology
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• v.50 no.8
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• pp.1349-1354
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• 2018

Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES) is widely used for the determination of trace elements in geological samples in Iran. In this paper, we have calculated the detection limits of neutron activation analysis (NAA) for some of the common elements in such samples utilizing the ORIGEN and MCNP codes and verified the simulations using the experimental results of three soil standard reference materials, namely, G02.SRM, G18.SRM, and G28.SRM. The results show that while the detection limit of ICP-AES method is usually in the mg/kg range, it is represented to the ${\mu}g/kg$ range for most of the elements of interest using the NAA method, and the simulations can be verified in a tolerance range of 20%.

• The Journal of Korean Society for Radiation Therapy
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• v.11 no.1
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• pp.73-78
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• 1999

In general, the patients of the head and neck cancer are treated with 4MV photon beam up to prescribed dose, but spinal cord should be excluded in the treatment field. When its absorbed dose is limited at the tolerance dose. In case of the patients who has the positive posterior neck nodes need a boost electron beam treatment to the prescribed dose. In that case, the anatomical structure of the neck and the physical structure of the standard electron cone interrupt to allow proper access to the disease site. Therefore, we extended treatment SSD for the remove of the those hindrances. In this study, we evaluated the dosimetric variation of the standard electron cone for the extended SSD, from 100cm to 120cm, 5 cm increment, and compare to the custom-made electron cone. As a result, the $\%$ depth dose, the point of maximum dose and the range of maximum were changed within the $2\%$. The penumbra width was increased from 1.0cm to 2.0cm. However, the dosimetric characteristics of the custom-made electron cone was very similar to that of the 100cm SSD standard electron cone and due to its characteristic of physical structure, patients didn't need re-positioning after photon beam treatment, therefore accurate treatment was possible, we conclude that the custom-made electron cone was very useful for the clinical practice.

• Progress in Medical Physics
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• v.30 no.4
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• pp.160-166
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• 2019

This study examined the clinical use of two newly installed computed tomography (CT) simulators in the Department of Radiation Oncology. The accreditation procedure was performed by the Korean Institute for Accreditation of Medical Imaging. An Xi R/F dosimeter was used to measure the CT dose index for each plug of the CT dose index phantom. Image qualities such as the Hounsfield unit (HU) value of water, noise level, homogeneity, existence of artifacts, spatial resolution, contrast, and slice thickness were evaluated by scanning a CT performance phantom. All test items were evaluated as to whether they were within the required tolerance level. CT calibration curves-the relationship between CT number and relative electron density-were obtained for dose calculations in the treatment planning system. The positional accuracy of the lasers was also evaluated. The volume CT dose indices for the head phantom were 22.26 mGy and 23.70 mGy, and those for body phantom were 12.30 mGy and 12.99 mGy for the first and second CT simulators, respectively. HU accuracy, noise, and homogeneity for the first CT simulator were -0.2 HU, 4.9 HU, and 0.69 HU, respectively, while those for second CT simulator were 1.9 HU, 4.9 HU, and 0.70 HU, respectively. Five air-filled holes with a diameter of 1.00 mm were used for assessment of spatial resolution and a low contrast object with a diameter of 6.4 mm was clearly discernible by both CT scanners. Both CT simulators exhibited comparable performance and are acceptable for clinical use.

• Journal of Astronomy and Space Sciences
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• v.22 no.4
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• pp.537-558
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• 2005

This paper addresses the results of HAUSAT-2 radiation environment and effect analyses, including TID and SEE analyses. Trapped proton and electron, solar proton, galactic cosmic ray models were considered for HAUSAT-2 TID radiation environment analysis. TID was analyzed through total dose-depth curve and the radiation tolerance of TID for HAUSAT-2 components was verified by using DMBP method and sectoring analysis. HAUSAT-2 LET spectrum for heavy ion and proton were also analyzed for SEE investigation. SEE(SEU, SEL) analyses were accomplished for MPC860T2B microprocessor and K6X8008T2B memory. It was estimated that several SEUs may occur without SEL during the HAUSAT-2 mission life(2 years). Software Hamming Code EDAC has been implemented to detect and correct the SEU. In this study, all radiation analyses were conducted by using SPENVIS software.