• Environmental Analysis Health and Toxicology
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• v.9 no.1_2
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• pp.9-17
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• 1994

The Ha-antagonist, cimetidine, has been shown to retard the hepatic elimination of low and high clearance drugs, and this has been attributed to inhibition of microsomal cytochrome P-450. This study was done to determine the effects of low (50$\mu\textrm{g}$) and high (1mg) dose of famotidine, another histamine H$_2$-receptor antagonist, on hepatic elimination of propranolol compared with cimetidine in the isolated perfused rat liver. Both low and high dose of cimetidine not only inhibited the elimination of propranolol but also increased the area under the perfusate propranolol concentration time curve (AUC). In contrast, low and high dose of famotidine did not affect hepatic elimination of propranolol. Our findings suggest that famotidine has not a propensity for hepatic microsomal inhibition.

• Korean Journal of Digital Imaging in Medicine
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• v.15 no.2
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• pp.39-44
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• 2013

Purpose : The purpose of this study is the magnification rates depending on the area of patient dose (DAP) and glass dosimeter see the change of the dose according to the dose characteristics of low-magnification aims to raise standards. Materials and Method : Direct DR equipment Sonialvision DAR-8000f, Shimadzu was used, the patient entrance dose measurements to the surface of the Rando Phantom of the neck and the abdomen was placed on the Xi unfors. glass dosimeter for measuring organ doses at the same time the Rando Phantom of the major organs in place by inserting a 9 ", 12", 15 ", 17" and 30 seconds for each magnification were measured according in fluoroscopy. DAP meter area of the patient dose was measured. Result : Esophagography at 17" 143% than 9"magnification the average area dose was increased. Organ dose of Esophagography at 17" was decreased 25.32% than 9" magnification. UGI at 17" was increased 129.73% DAP than 9" magnification. Organ dose of UGI at 17" was decreased 23.32% than 9" magnification. Where the major organs of magnification at 17" were decreased(lung -25.96%, stomach -33.09%, spleen -27.81%, liver -4.92%) than 9" magnification. Conclusion : Expected to get better quality image While using the proper magnification, and have recognition that difference Organ doses and DAP meter in fluoroscopy.

• Radiation Oncology Journal
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• v.35 no.4
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• pp.380-384
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• 2017

Massive chylous leakage is a rare postoperative complication that can prolong hospital stay and cause secondary morbidities. Conservative management strategies are the treatment of choice; however, radiation therapy (RT) can be used as an alternative for cases that are refractory to conservative treatment. Herein, we report a 69-year-old female patient who suffered from massive chylous leakage after subtotal gastrectomy. Due to persistent massive chylous leakage, she was scheduled to undergo low-dose RT. Radiation was delivered with a daily dose of 1 Gy, using an anterior-posterior and posterior-anterior beam arrangement. The clinical target volume encompassed the entire lymph node area of the D2 dissection. RT was completed at the total dose of 8 Gy because the amount of chylous leakage declined rapidly. Percutaneous drainage tube was removed after 3 days of RT. The patient did not complain of any symptoms related to massive chylous leakage 2 years after the completion of RT.

• Journal of radiological science and technology
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• v.44 no.4
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• pp.295-300
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• 2021

This study aims to present new chest AP examination exposure conditions through a study on the effect on image quality and patient dose by applying high tube voltage and scatter ray post-processing software during chest AP examination in digital radiography equipment. This study was used a human body phantom and in the chest AP position, the dosimeter was placed horizontally at the thoracic spine 6. The experiment was conducted by dividing into a low tube voltage (70 kVp, 400 mA, 3.2 mAs) group and a high tube voltage (100 kVp, 400 mA, 1.2 mAs) group. The collimation size (14″× 17″) and the source to image receptor distance(110 cm) were same applied to both groups. Radiation dose was presented to dose area product and entrance surface dose. Image quality was compared and analyzed by comparing the difference between the signal-to-noise ratio and the contrast-to-noise ratio of the image according to the application of the scatter ray post-processing software under each condition. The average value of the entrance surface dose in the low and high tube voltage conditions was 93.04±0.45 µGy and 94.25±1.51 µGy, which was slightly higher in the high tube voltage condition, but the dose area product was 0.97±0.04 µGy and 0.93±0.01 µGy. There was a statistically significant difference in the group mean value(p<0.01). In terms of image quality, the values of the signal-to-noise ratio and the contrast noise ratio were higher in the high tube voltage than in the low tube voltage, and decreased when the scattering line post-processing function was used, but the contrast resolution was improved. If there is a scatter ray post-processing function during chest AP examination, it is helpful to actively utilize it to improve the image quality. However, when this function is not available, I thought that applying a higher tube voltage state than a low tube voltage state will help to realize images with a large amount of information without changing the dose.

• Journal of Radiation Protection and Research
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• v.28 no.3
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• pp.225-231
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• 2003

Up-front irradiation technique as 3-dimensional conformation, or intensity modulation has kept large proportion of brain tumors from being complicated with acute radiation reactions in the normal tissue during or shortly after radiotherapy. For years, we've cannot help but counting on 2-D vertex beam technique to reduce acute reactions in the brain tumor patients because we're not equipped with 3-dimensional planning system. We analyzed its advantages and limitations in the clinical application. From 1998 to 2001, vertex or oblique vertex beams were applied to 35 patients with primary brain tumor and 25 among them were eligible for this analysis. Vertex(V) plans were optimized on the reconstructed coronal planes. As the control, we took the bilateral opposed techniques(BL) otherwise being applied. We compared the volumes included in 105% to 50% isodose lines of each plan. We also measured the radiation dose at various extracranial sites with TLD. With vertex techniques, we reduced the irradiated volumes of contralateral hemisphere and prevented middle ear effusion at contralateral side. But the low dose volume increased outside 100%; the ratio of V to BL in irradiated volume included in 100%, 80%, 50% was 0.55+/-0.10, 0.61+/-0.10, and 1.22+/-0.21, respectively. The hot area within 100% isodose line almost disappeared with vertex plan; the ratio of V to BL in irradiated volume included in 103%, 105%, 108% was 0.14+/-0.14, 0.05./-0.17, 0.00, respectively. The dose distribution within 100% isodose line became more homogeneous; the ratio of volume included in 103% and 105% to 100% was 0.62+/-0.14 and 0.26+/-0.16 in BL whereas was 0.16+/-0.16 and 0.02+/-0.04 in V. With the vertex techniques, extracranial dose increased up to $1{\sim}3%$ of maximum dose in the head and neck region except submandibular area where dose ranged 1 to 21%. From this data, vertex beam technique was quite effective in reduction of unnecessary irradiation to the contralateral hemispheres, integral dose, obtaining dose homogeneity in the clinical target. But it was associated with volume increment of low dose area in the brain and irradiation toward the head and neck region otherwise being not irradiated at all. Thus, this 2-D vertex technique can be a useful quasi-conformal method before getting 3-D apparatus.

• Progress in Medical Physics
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• v.27 no.3
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• pp.146-155
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• 2016

As the probability of exposure to radiation increases due to an increase in the use of radioisotopes and radiation generators, the importance of a radiation safety management field is being highlighted. We intend to help radiation workers with exposure management by identifying the degree of radiation exposure and contamination to determine an efficient method of radiation safety management. The personal exposure doses of the radiation workers at the Korea Institute of Radiological & Medical Sciences measured every quarter during a five-year period from Jan. 1, 2011 till Dec. 31, 2015 were analyzed using a TLD (thermoluminescence dosimeter). The spatial dose rates of radiation-controlled areas were measured using a portable radioscope, and the level of surface contamination was measured at weekly intervals using a piece of smear paper and a low background alpha/beta counter. Though the averages of the depth doses and the surface doses in 2012 increased from those in 2011 by about 14%, the averages were shown to have decreased every year after that. The exposure dose of 27 mSv in 2012 increased from that in 2011 in radiopharmaceutical laboratories and, in the case of the spatial dose rate, the rate of decrease in 2012 was shown to be similar to the annual trend of the whole institute. In the case of the surface contamination level, as the remaining radiation-controlled area with the exception of the I-131 treatment ward showed a low value less than $1.0kBq/m^2$, the annual trend of the I-131 treatment ward was shown to be similar to that of the entire institute. In conclusion, continuous attention should be paid to dose monitoring of the radiation-controlled areas where unsealed sources are handled and the workers therein.

• Journal of Institute of Control, Robotics and Systems
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• v.9 no.4
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• pp.296-303
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• 2003

A personal portable type electronic dosimeter using silicon PIN photodiode and small GM tube is recently attracting much attention due to its advantages such as an immediate indication function of dose and dose rate, alerting function, and efficient management of radiation exposure history and dose data. We designed and manufactured a semiconductor radiation detector aimed to directly measure X-ray and v-ray irradiated in silicon PIN photodiode, without using high-priced scintillation materials. Using this semiconductor radiation detector, we developed an active electronic dosimeter, which measures the exposure dose using pulse counting method. In this case, it has a shortcoming of over-evaluating the dose that shows the difference between the dose measured with electronic dosimeter and the dose exposed to the human body in a low energy area. We proposed an energy compensation filter and developed a dose conversion algorithm to make both doses indicated on the detector and exposed to the human body proportional to each other, thus enabling a high-precision dose measurement. In order to prove its reliability in conducting personal dose measurement, crucial for protecting against radiation, the implemented electronic dosimeter was evaluated to successfully meet the IEC's criteria, as the KAERI (Korea Atomic Energy Research Institute) conducted test on dose indication accuracy, and linearity, energy and angular dependences.

• 전기의세계
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• v.23 no.5
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• pp.54-60
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• 1974

Proposals were mode on how to differentiate radiation effects in morphological phases of polyethylene and discussions were developed with the results obtained on a low density polyethylene, SOCAREX, specified by number average molecular weight; overbar Mn=5,400, density; 0.92, and degree of branch; 3.4/100 carbon atom, which was irradiated to Co$^{60}$ .gamma. ray at the dose rate of 0.5 Mrad/hr in ambient temperature under the pressure of 10$^{-5}$ Torr. or 1 atm. respectively. The effect to crystalline phase in possibly deduced from dose dependent variation of relative area between (110) and (200) peaks on X ray diffraction spectrum and that, the effects to amorphous phase can be understood through dose dependent relaxation behaviours of .betha. peak on internal friction characteristics of the specimen. The results obtained thus far indicate that, in crystalline phase, relative crystallinity shows a rather rapid decrease up to 20 Mrad with increasing dose, however, little change of crystallinity can be observed in the region between 20-200 Mrad, and degradation appears to be more predominant than crosslinking up to 60 Mrad. While in amorphous phase the indication also shows that degradation is only predominant up to 20 Mrad. Furthermore several correlations can be seen with amenable explanation between dose dependent behaviours observed in both phases.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.7
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• pp.3412-3418
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• 2013

The Purpose of this study was to evaluate by comparing the dose change and build up characteristic according to delay time in 30 days of glass dosimeter processed preheat and non preheat when measuring accumulation dose of radiation by using glass dosimeter over the long haul. For obtaining low dose with 0.1 mGy, 1 mGy and 5 mGy, we employed diagnostic generator AccuRay-650R. We compared the build up characteristic over the long haul by exposuring radiation to 30 glass dosimeters sorted into 10 glass dosimeters per tube voltage and current. In Non preheat glass dosimeter, initial measured dose was inferior to exposed dose but as time goes on, was close to exposed dose steadily. In 72 hour after experiment end, non preheat glass dosimeters were not indicated the difference from preheat glass dosimeters and statistical analysis were meaningful (p>0.05). Initial measured dose for low glass dosimeter processed preheat was close to exposed dose and stable. After 15 days dose was gradually increased. Previous study characteristics of glass dosimeter were with respect to characteristic of glass dosimeter in high dose of high energy area. However, in this study, we make a judgment to measure the dose of glass dosimeter without preheat processing when measuring the accumulation dose of low dose in conclusion.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.10a
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• pp.25-25
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• 2018

The Fukushima Daiichi Nuclear Power Plant accident in March 2011 caused severe radioactive contamination in the surrounding environment. Since the accident, much attention has been paid to the biological and genetic consequences of organism inhabiting the contaminated area. The effect of radiation exposure on genetic mutation rates is little known, especially for low doses and in situ conditions. Evaluating DNA mutation by low levels of radiation dose is difficult due to the rare mutation event and lack of sequence information before the accident. In this study, correlations with air dose levels and somatic DNA mutation rates were evaluated using Next Generation Sequencer for the clonal plant, Phyllostachys edulis. This bamboo is known to spread an identical clone throughout Japan, and it has the advantage that we can compare genetic mutation rate among identical clone growing different air dose levels. We collected 94 samples of P. edulis from 14 sites with air dose rates from $0.04{\sim}7.80{\mu}Gy/h$. Their clonal identity was confirmed by analysis using 24 microsatellite markers, and then, sequences among samples were compared by MIG sequence. The sequence data were obtained from 2,718 loci. About ~200,000 bp sequence (80 bp X 2,718 loci) were obtained for each sample, and this corresponds to about 0.01% of the genome sequence of P. edulis. In these sequences, 442 loci showed polymorphism patterns including recent origin mutation, old mutation, and sequence errors. The number of mutations per sample ranged from 0 to 13, and did not correlate with air dose levels. This result indicated that DNA mutations have not accumulated in P. edulis living in the air doses levels less than $10{\mu}Gy/h$. Our study also suggests that mutation rates can be assessed by selecting an appropriate experimental approach and analyzing with next generation sequencer.