• Journal of Radiation Protection and Research
• /
• 제9권2호
• /
• pp.112-117
• /
• 1984

A lot of radioisotopes are applied to medical fields. It's very important to measure the activities on airborne radioiodine discharged in air from $Na^{131}I$ solutions and from patients treated with radioiodine. Also surface decontamination is another one important problem to be completly solved in the isotope laboratory where there is always the possibility of radiation contamination. The Authors measured the activities on airborne radioiodine with RI collector and scintillation counter. 1. The mean accumulative activity of airborne radioiodine discharged into air from $Na^{131}I$ solution was measured as $1.3{\times}10^{-3}/hr$ rate, and the maximum value was $1.8{\times}10^{-3}/hr$. 2. Radioactivity rate per hour of airborne iodine discharged into air from patients treated with $Na^{131}I$ was measured as $6.2{\times}10^{-5}/hr$ at 8 hour after administration of radioiodine and decreased into $2{\times}10^{-6}/hr$ after 24 hour. 3. Metalic surfaces such as stainless steel or aluminum are decontaminated 5 to 6 times more rapidly than wood and concrete surfaces. 4. Decontamination with wet wiping with detergent was 9 to 10 times more rapidly than dry wiping method, but dry wiping was useful for the first step to prevent spreading and flowing from liquid radioactive materials.

• 한국전산유체공학회:학술대회논문집
• /
• 한국전산유체공학회 2005년도 춘계 학술대회논문집
• /
• pp.70-73
• /
• 2005

The HANARO, multi-purpose research reactor, 30 MWth open-tank-in-pool type, is planning to produce a fission moly-99 of radio isotopes, a mother nuclide of Tc-99m, a medical isotope and is under developing a target handling tool for loading and unloading it in a circular flow tube (OR-5). A guide tube is extended from the reactor core to the top of the reactor chimney for easily loading the target under the reactor normal operation. But active coolant through the core can be quickly raised up to the top of the chimney through the guide tube. The jet flow was suppressed in the guide tube after reducing the inner diameter of a flow restriction orifice installed in the OR-5 flow tube for adding the pressure difference in the flow tube after unloading the target. This paper describes an analytical analysis to calculate the flow distribution in the core of the HANARO after suppressing the jet flow of the guide tube. As results, it was confirmed through the analysis results that the flow distribution in the core of the HANARO were not adversely affected.

• 한국주조공학회지
• /
• 제27권5호
• /
• pp.224-227
• /
• 2007

원자로에 장전되는 $^{99}Mo$ 조사표적을 제조하기 위한 우라늄박판은, 박판 품질, 생산성, 경제성 문제로 인해, 기존의 열간압연방법에 의해 실험실 규모로는 제조가 가능하나, 상용 규모로는 제조되기 어려운 실정이므로, 새로운 제조방법의 개발이 요구되고 있다. 이와 같은 상황에서, $^{99m}Tc$의 모핵종인 방사선 동위원소$^{99}Mo$ 생산하기 위하여 planar flow casting (PFC) 법에 의해 다결정질 우라늄박판에 대한 새로운 제조방법이 연구되었다. $100{\sim}150\;{\mu}m$의 두께 및 너비 약 50mm의 연속적인 다결정질 우라늄박판이 하나의 batch에서 5m 이상의 길이로 제조되었다. 우라늄박판은 불순물이 거의 없었으며 양호한 표면조도를 가지고 있었다. 우라늄박판의 냉각를 접촉표면은 자유표면 보다 매끈한 자유표면을 가지고 있었다. 우라늄박판은 제조공정변수와는 상관없이 ${\alpha}-U$ 상을 가진 약 10 ${\mu}m$ 이하의 미세한 다결정립을 가지고 있었다.

• 한국식품영양과학회지
• /
• 제15권3호
• /
• pp.306-312
• /
• 1986

Demonstration of the highly positive correlation between blood cholestrol levels and heart disease has made consumers wary of the fats in meat, milk and eggs. The egg, as perhaps the single largest common source of cholesterol, has been cited by many members of the medical and scientific world as a food contributing to heart disease. In light of decreasing per capita egg consumption and continuing dietary egg cholesterol controversy, many researchers have focused their efforts on egg nutrition. The results reported, however, are often contradictory. In spite of the disputable scientific evidence, the egg has been labelled (erroneously) as a highly cholesterogenic food. The objective of this presentation is to present a general picture of the problem and discuss our laboratory findings relevant to the problem. An isotope technique was utilized to incorporate $^{14}C$-cholesterol into egg yolk lipoproteins and study the metabolic fate of dietary ovo-cholesterol in rats. Two hundred and fifty micro-curies of 4-$^{14}C$-cholesterol, emulsified in corn oil, were orally administered to five Single Comb White Leghorn laying hens. Eggs were collected, hard-boiled, and the hot dried egg yolk powder (HEY) was prepared. Total radioactivity excreted via feces was determined. The rat groups fed egg yolk powder excreted more than 95% of the ingested ovo-cholesterol, whereas the rat chow group excreted only 47%. No difference was observed between HEY and CEY treatments. Therefore, an unknown lipid factor present in egg folk accelerates cholesterol turnover rate and excretion via feces.

• Nuclear Engineering and Technology
• /
• 제52권7호
• /
• pp.1517-1523
• /
• 2020

The widely used medical isotope technetium-99 m (^99mTc) is a daughter of Molybdenum-99 (⁹⁹Mo), which is mainly produced using dedicated research reactors from the nuclear fission of uranium-235 (²³⁵U). ^99mTc has been used for several decades, which covers about 80% of the all the nuclear diagnostics procedures. Recently, the instability of the supply has become an important topic throughout the international radioisotope communities. The aging of major ⁹⁹Mo production reactors has also caused frequent shutdowns. It has triggered movements to establish new research reactors for ⁹⁹Mo production, as well as the development of various ⁹⁹Mo production technologies. In this context, a new research reactor project was launched in 2012 in Korea. At the same time, the development of fission-based ⁹⁹Mo production process was initiated by Korea Atomic Energy Research Institute (KAERI) in 2012 in order to be implemented by the new research reactor. The KAERI process is based on the caustic dissolution of plate-type LEU (low enriched uranium) dispersion targets, followed by the separation and purification using a series of columns. The development of proper waste treatment technologies for the gaseous, liquid, and solid radioactive wastes also took place. The first stage of this process development was completed in 2018. In this paper, the results of the hot test production of fission ⁹⁹Mo using HANARO, KAERI's 30 MW research reactor, was described.

• 대한방사선기술학회지:방사선기술과학
• /
• 제43권5호
• /
• pp.375-382
• /
• 2020

PET/CT is a medical equipment that detects 0.511 MeV of gamma rays. The radiation workers are inevitably exposed to ionizing radiation in the process of handling the isotope. Accordingly, PET/CT workers use syringe shields made of lead and tungsten to protect their hands. However, lead and tungsten are known to generate very high scattering particles by interacting with gamma rays. Therefore, in this study, we tried to find out the effect on the scattering particles emitted from the syringe shield. In the experiment, first, the exposure dose to the hand (Rod phantom) was evaluated according to the metal material (lead, tungsten, iron, stainless steel) using Monte Carlo simulation. The exposure dose was compared according to whether or not plastic is attached. Second, the exposure dose of scattering particles was measured using a dosimeter and lead. As a result of the experiment, the shielding rate of plastics using the Monte Carlo simulation showed the largest difference in dose of about 40 % in lead, and the lowest in iron, about 15 %. As a result of the dosimeter test, when the plastic tape was wound on lead, it was found that the reduction rate was about 15 %, 28 %, and 39 % depending on the thickness. Based on the above results, it was found that 0.511 MeV of gamma ray interacts with the shielding tool to emit scattered rays and has a very large effect on radiation exposure. However, it was considered that the scattering particles could be sufficiently removed with plastics with a low atomic number. From now on, when using high-energy radiation, the shielding tool and the skin should not be in direct contact, and should be covered with a material with a low atomic number.

• Journal of Acupuncture Research
• /
• 제19권1호
• /
• pp.159-174
• /
• 2002

Objective : The meridian theory in oriental medicine explains that each acu-point has a characteristic functional effect. It will be supposed that an acupuncture stimulation on different acu-point evokes different activation on different areas in the central nervous system(CNS) according to the meridian theory. On this supposition, our group tried the semi-quantitative [14C]2-deoxyglucose([14C]2-DG) autoradiography on the acupuncture stimulation to the hindlimb acu-points of Sprague-Dawley rats. Methods : A venous catheter for the intravenous administration of isotope was equipped in the right external jugular vein on 3 days prior to the [14C]2-DG study. On the day of the study, two acupuncture needles were inserted into the ST36(Zusanli) or LR3(Taichong) on the left hindlimb. Electro-acupuncture stimulation (2 Hz, 5 ms, 1~3 mA, 15 minutes) started just before the i.v. injection of [14C]2-DG ($25{\mu}Ci/rat$). The brain and the spinal cord were removed and processed for the [14C] 2-DG autoradiography. Results : The EA stimulation on ST36 reveals over 120% metaboilc activation in Arcuate nucleus, Anterior pretectal nucleus, Dorsal cochlear nucleus, Interposed cerebellar nucleus, and Nucleus of Darkschewitsch. The EA stimulation on LR3 reveals over 120% metaboilc activation in Lateral habenula nucleus, Medial vestibular nucleus, Ventromedial thalamic nucleus, Anteroventral thalamic nucleus, Anterior cingulate cortex, Dentate gyrus, Antero cortical amygdaloid nucleus, Anterior pretectal nucleus, and Dorsal tegmental nucleus compared with the non EA stimulation control group. Conclusion : These results demonstrate that the different acu-points evoke the different activations in brain areas. And with this functional brain mapping study, a new scientific elucidation for the basis of the acupuncture-meridian theory in oriental medicine through differences of activated area in CNS according to the each acupuncture point.

• Journal of Acupuncture Research
• /
• 제18권3호
• /
• pp.56-68
• /
• 2001

Objective : Functional brain mapping study on acupuncture stimulation using the [14C]2-deoxyglucose([14C]2-DG) autoradiography provides quantitative data and visualized pathway in central nervous system(CNS). We aimed to investigate the neural pathway and spatial distribution of metabolic activity elicited in CNS on electroacupuncture stimulation using [14C]2-DG autoradiography. Methods : The study were divided into three groups by stimulation times. 45-mins stimulation group according to Sokoloffs method, 5-mins stimulation group according to Duncun's method, and 15-mins stimulation group. ;A venous catheter was equipped into right jugular vein. The rats (Sprague-Dawley rats, 230-260g) were kept fastened loosely on a holding platform without anesthesia. Electroacupuncture stimulation (5 ms, 2 Hz, 1~3 mA) were applied on the left Zusanli (ST36) acupoint and [14C]2-DG ($25{\mu}Ci/rat$) injection was performed through the catheter. After sacrifice, the brain and the spinal cord were made to sections for film image. The film images were digitalized as the isotope concentration based upon comparison of optical densities with that of the standards and normalized by the optical density of corpus callosum. Results : 1. 15-mins stimulation group was most effective among 3 experiments. 2. On 15-mins stimulation group, medial geniculate nucleus, intetpeduncular nucleus intermedius, ventral periolivary nucleus, caudal periolivary nucleus, medial superior olive, lateral paragigantocellular nucleus, including hypothalamic arcuate nucleus were increased by more than 25% (at least, p<0.05) by electroacupuncture stimulation. 3. Especially, the metabolism in hypothalamic arcuate nucleus was increased by 90% (p<0.05). 4. The fact that arcuate nucleus of hypothalamus might play a role of interconnection area between ascending and descending pathway of acupuncture stimulation was demonstrated visually. Conclusions : Advanced study on electroacupuncture stimulation elicited significant increase of metabolic activity in various nuclei of hypothalamus will provide the important experimental basis in research of the relationship between electroacupuncture stimulation and internal visceral functions.

• Tuberculosis and Respiratory Diseases
• /
• 제47권4호
• /
• pp.525-532
• /
• 1999

악성질환에서 체액성 고칼슘혈증은 주로 부갑상선호르몬관련단백질(parathyroid hormone related hormone ; PTHrP)이 매개물질로 작용하여 발생한다. 이러한 PTHrP포 인한 고칼슘혈중이 발생한 경우에는 원발성부갑상선기능항진증을 동반한 경우를 제외하고는 모든 환자에서 부갑상선호르몬(PTH) 농도는 저하되며 PTHrP는 증가하는 것으로 알려져있다. 특히 부갑상선이외의 종양에서 이소성 부갑상선호르몬을 생성한다거나 PTH와 PTHrP를 동시에 산생하는 경우는 매우 드물다. 저자들은 고칼슘혈증을 동반한 편평상피세포 폐암환자에서 혈청 부갑상선호르몬(PTH)과 부갑상선호르몬관련단백질(PTHrP)이 동시에 증가된 1례를 경험하여 이에 보고한다. 61세 남자 환자로서 혈청 칼슘은 7.5 mEq/L로 증가되어 있었으며, iPTH와 PTHrP(C 말단 부위 : 109-138)는 각각 150 pg/mL, 99.1 pmol/L로 모두 상승되어 있었다. 골전이나 부갑상선 기능 장애의 동반여부를 알기 위해서 시행한 골스캔이나 경부초음파, 전산화단층촬영, Tc-99m MIBI 스캔 검사에서 모두 정상소견을 보였다. 결론적으로, 본 증례는 고칼슘혈증을 보인 편평상피상피세포 폐암환자에서 PTH와 PTHrP가 동시에 증가된 경우이다. 이러한 매개물이 동시에 증가한 원인으로 PTH와 PTHrP을 분비하는 타병변이 있을 수 있지만, PTH와 PTHrP를 동시에 분비할 수 있는 주된 기관인 부갑상선에 대한 상기 검사상 특이한 이상소견이 없었던점으로 미루어 보아 편평상피세포 폐암조직으로부터 이소성 PTH와 PTHrP가 동시에 분비되었을 가능성도 있다.

• 한국방사선학회논문지
• /
• 제13권3호
• /
• pp.433-438
• /
• 2019

의료기관에서는 환자의 진단 및 치료를 위해 방사선발생장치 및 방사성동위원소를 사용하고 있다. 환자이송원은 환자이송을 위해 불가피하게 방사선 관리구역에 출입하거나, 동위원소가 투여된 환자를 근거리에서 이송하는 등 일반인과 비교했을 때, 방사선에 노출될 확률이 높은 환경에서 업무를 수행한다. 따라서 환자이송원의 피폭 정도를 알아보고자 연구를 진행했다. 인천 A 종합병원에서 근무하고 있는 12명의 환자이송원을 대상으로 2019년 4월 1일부터 4월 30일까지 한 달 동안 선량계를 가슴에 패용하고, 누적된 선량을 측정했다. 사용된 선량계는 광자극발광선량계(OSLD), 선량판독은 OSLD Microstar Reading System을 사용했다. 한 달 동안 누적선량 측정 결과 심부선량은 평균 0.13 mSv, 표층선량은 평균 0.13 mSv로 측정되었고, 한 달 동안 누적된 선량에 12를 곱해 일 년 동안 업무를 수행할 시 받게 될 누적선량 예상치를 추정한 결과 심부선량은 평균 1.52 mSv, 표층선량은 평균 1.51 mSv로 나타났다. 환자이송원의 수시출입자 분류를 통해 피폭선량을 측정, 관리 하고, 교육훈련을 통해 방사선에 대한 방호지식을 높이며 건강진단을 통해 방사선장해 발생을 방지하기 위한 노력이 필요하다.