고용량 방사성옥소 치료를 받은 갑상선분화암 환자에서 Dual Time I-131 Whole Body Scan을 이용한 유효반감기의 측정

윤재식,이재곤,이기현,임광석,최학기,이상미,Yoon, Jae Sik,Lee, Jae Gon,Lee, Ki Hyun,Lim, Kwang Seok,Choi, Hak Ki,Lee, Sang Mi 대한핵의학기술학회 2014 핵의학 기술 Vol.18 No.1

갑상선 분화암 환자의 방사선 치료에서 I-131의 유효반감기는 환자에게 투여하는 양의 계산뿐만 아니라 환자의 격리 입원기간의 결정, 환자로부터 가족들이 받게 되는 선량을 계산하는데 유용한 값이다. 하지만 이 값은 물리적반감기와는 달리 실측을 해야만 얻을 수 있어 입원 격리중인 환자에게 계측하기가 기술적으로 어려운 문제가 있다. Dual time I-131 whole body scan의 초기촬영과 지연촬영 사이의 체내잔류방사능량을 이용하여 전신과 갑상선에 유효반감기를 추정해 보았다. 또한 혈중 크레아티닌 농도, GFR, 투여량이 유효반감기와 상관관계가 있는지 알아보았다. 유효반감기 측정을 위해 전신에 체내잔류방사능량과 갑상선의 잔류방사능량을 측정하기 위해 환자의 전신을 흥미영역으로 설정한 후 배후방사능을 보정하여 전신의 체내잔류방사능량을 획득하였고, 갑상선 부위에 ROI를 설정한 후 배후 방사능을 보정하여 갑상선의 잔류방사능량을 획득하였다. 초기영상과 지연영상의 측정값 사이의 비율을 계산하여 전신과 갑상선의 유효반감기를 구하였다. 또한 유효반감기와 GFR, 혈중크레아티닌 농도, I-131 투여량과의 상관관계를 분석하였다. 전신의 체내잔류방사능량을 측정한 값의 유효반감기는 $17.06{\pm}5.50$시간으로 나타났고 갑상선의 잔류방사능량을 측정한 값의 유효반감기는 $17.22{\pm}5.41$시간으로 나타났으며 두 유효반감기는 유의한 차이를 보이지 않았다(P=0.887). GFR 값이 올라갈수록 전신의 유효반감기(r=-0.407, P=0.003)와 갑상선 유효반감기(r=-0.473, P=0.001) 모두 유의하게 감소하였으며 혈중크레아티닌 농도가 올라갈수록 전신의 유효반감기(r=0.309, P=0.029)와 갑상선 유효반감기(r=0.371, P=0.008) 모두 유의하게 증가하였다. 투여량은 두유효반감기와 상관관계를 보이지 않았다. 본 연구를 통해 고용량 방사성요오드 치료환자 입원기간의 최적화 연구와 기존 유효반감기를 구하기 위해 종사자의 피폭 및 복잡성을 보완하여 간편하게 측정을 할 수 있을 것이라 생각한다. 또한 분석된 갑상선의 유효반감기를 적용한 MIRD schema의 내부피폭선량 평가 연구에도 활용할 수 있을 것으로 사료된다. Purpose: The effective half life of I-131 is useful to calculate radiation dose, period of hospitalization, and exposure dose of surrounding people from patient. However, it is difficult to measure. This study estimates the effective half life in whole body and thyroid in using of value of residual radioactivity obtained from the early and delay images of Dual time I-131 whole body scan. Also, the correlations between the effective half life and serum creatinine, GFR, and administration dose were investigated in this study. Materials and Methods: The targets were 50 patients administration high dose of I-131 from February to August in 2013, having normal range of serum creatinine and over $30{\mu}IU/mL$ of TSH levels. After administration radioactive I-131, the early scan in the 3rd day and the delay scan in the 5-6th days were performed. To measure the residual radioactivity in the whole body and thyroid, ROI was set and then background radioactivity was corrected to estimate. The effective half life was estimated by calculating the ratio of measured values between the early and delay images. To compare the effective half lives of the whole body and thyroid, it was analyzed by Independent t-test, and each correlation of the effective half life, GFR, serum creatinine, and the dose of administration were analyzed by calculating the pearson's correlation coefficient. All of the analysis were determined to be statistically significant when P<0.05. Results: The effective half life of the whole body was $17.06{\pm}5.50$ hours and of the thyroid was $17.22{\pm}5.41$ hours. The two effective half life did not show significant difference (P=0.887). As the value of GFR was increased, the effective half life of whole body (r=-0.407, P=0.003) and of thyroid (r=-0.473, P=0.001) were significantly decreased; as the value of serum creatinine was increased, the effective half life of whole body (r=0.309, P=0.029) and of thyroid (r=0.371, P=0.008) were significantly increased. In the administration dose, effective half life did not have correlations. Conclusion: The effective half life of I-131 of patients treated for their thyroids were estimated only by using the images of Dual time I-131 whole body scan. Also, the correlations with the effective life, GFR, and serum creatinine were examined. This study might be utilized for a study on optimization for the period of hospitalization of patients treated by high dose of I-131 and on evaluation for internal absorbed dose of MIRD schema in application of the effective half life.

금속열환원 공정에서 반응온도가 니오븀 분말 특성에 미치는 영향

윤재식,이영미,황선호,김병일,Yoon, Jae-Sik,Lee, Young-Mi,Hwang, Sun-Ho,Kim, Byung-Il 한국분말야금학회 2009 한국분말재료학회지 (KPMI) Vol.16 No.2

Niobium powder was made from potassium heptafluoroniobite ($K_2NbF_7$) as the raw material using sodium (Na) as a reducing agent based on the hunter process. The apparatus for the experiment was designed and built specifically for the present study. The niobium particle size greatly increased as the reduction temperature increased from $710^{\circ}C$ to $800^{\circ}C$. The particle size was fairly uniform, varying from $0.09{\mu}m$ to $0.4{\mu}m$ depending on the reduction temperatures. The niobium powder morphology and particle size are very sensitive to a reaction temperature in the metallothermic reduction process. The yield of niobium powder increased from 55% to 80% with a increasing a reaction temperature.

Na환원법에 의한 희석제량에 따른 탄탈 분말 제조와 특성

윤재식,박형호,배인성,김병일,정성만,Yoon, Jae-Sik,Park, Hyeong-Ho,Bae, In-Sung,Kim, Byung-Il,Jung, Sung-Man 한국재료학회 2002 한국재료학회지 Vol.12 No.9

High-pure tantalum powder was fabricated through Na reduction process and has been produced by using $K_2$TaF$_{7}$, and KCI, KF for raw material and diluent, respectively. A raw material and diluent were charged at the hestalloy bomb by the weight rate of 1:2, 1:1, 1:0.5 and 1:0.25 each other, investigated properties of morphology, chemical composition and yield and particle size after reduced. Ta metal has been achieved by reduction of $K_2$$TaF_{7}$ 500g with 1% sodium in excess of stoichiometric amount in the charge at a reduction temperature of $850^{\circ}C$ for 3hours. According to amount of the diluent, a formation of the powder doesn't have an effect. The diluent prevented the temperature rising caused from the heat of reaction and it maintained the speed of reducing reaction. But in the mixture ratio of raw material and diluent in the 1 : 2 and 1 : 0.25, an oxide and partially not reacted K were detected. As the amount of diluent increased, the size of tantalum powder decreased. According as raw material and the mixture ratio of diluent change from 1:0.25 to 1:2, the size is decreased from 5$\mu\textrm{m}$ to 1$\mu\textrm{m}$, and a particle size distribution which is below 325 mesh in fined powder increases from 71% to 83%. In the case of average size of Tantalum powder which is the mixture ratio (1:0.5), we would get the Ta powder with grain size about 3$\mu\textrm{m}$, which come close to the average size (2~4$\mu\textrm{m}$) of tantalum powder which is used commonly in the present is Ta powder about 3$\mu\textrm{m}$.

K₂NbF₇로부터 Na 열환원 공정에 의한 니오븀 분말의 제조

윤재식,Yoon, Jae-Sik 한국재료학회 2009 한국재료학회지 Vol.19 No.7

Niobium(Nb) and Tantalum(Ta) are rarely found apart in nature and never in the free state. The element niobium amounts to 3% of the crustal abundance. On the whole, the niobium capacitor showed somewhat more unstable characteristics than the commercial tantalum capacitors, but is nonetheless considered applicable as a future substitute for tantalum capacitors. In this study, niobium powder was made from potassium heptafluoroniobite($K_2NbF_7$) by using sodium(Na) as a reductant and KCl and KF as diluents based on the hunter sodiothermic reduction method.,In order to obtain a high surface area niobium powder via the sodiothermic reduction method, a certain amount of diluent, such as alkali metal halides selected from NaCl, KCl, KF and NaF, was added in the raw materials to be reduced. However, if a higher surface area of powder is required, more diluents need to be used in the said method in order to produce niobium powder. But when more diluents are used, the niobium powder will be contaminated with more impurities and the yield will also decreased.

고환고정술 : 10년간 임상경험

윤재식,김광세,Yoon, Jae-Sik,Kim, Kwang-Sae 대한소아외과학회 1999 소아외과 Vol.5 No.1

We analyzed our experience with orchidopexy for undescended testicle performed during recent 10 years in order to evaluate our results and to determine the most effective treatment of undecended testes. Between 1988 and 1997, we treated 420 undescended tested (314 palpable and 106 nonpalpable) in 356 boys. Medical records were reviewed with respect to age at presentation, the surgical approach, testicular location, testicular volume and the final outcome. The average patient age at presentation was 4.1 years with 40.2 % presenting before age 2 years. Of 106 nonpalpable testes, 23 testes were intra-abdominal, 32 were preperitoneal and 51 were absent. During the first 5 years, we performed orchidopexy through 31 inguinal and 13 midline transabdominal incisions for 44 paitents with nonpalpable testes. In the next 5 years, all 47 patients with nonpalpable were treated through inguinal incisions. For the nonpalpable testes, the inguinal approach with or without intraperitoneal extension was successful in defining the location of testes and blind-ending vessels in all patients. Laparoscopy did not help to avoid surgical exploration in all our patients with nonpalpable tests. Of 339 inguinal and midline tranabdominal orchidopexies without spermatic vessels ligations, 324 testes were placed in the scrotum, 4 in the upper scrotum and 3 in the inguinal area. Eight testes underwent atrophy. Of 13 Fowler-Stephens orchidopexies, 7 were placed in the scrotum and 6 became atrophied. Testicular growths were noticed in most patients who underwent orchidopexies and the colume of pexed testes became as large as the contralateral normal testes by the mean duration of 43.3 months postoperatively. In conclusion, orchidopexies were successful in most cases of cryptochidism in terms of testicular position and growth. However, there were more testicular atrophies in cases where spermatic vessels were ligated. In cases of nonpalpable undescended testes, the inguinal approach with or without intraperitoneal extesion would be recommended.

고체 전해커패시터용 니오븀 분말제조

윤재식(Jae-Sik Yoon),황선호(Sun-Ho Hwang),김병일(Byung-Il Kim) 한국표면공학회 2009 한국표면공학회지 Vol.42 No.5

The niobium capacitor showed somewhat more unstable characteristics than the commercial tantalum capacitors, but is nonetheless considered applicable as a future substitute for tantalum capacitors. In this study, niobium powder was fabricated by metallothermic reduction process using K₂NbF? as the raw materials, KCl and KF as the diluents and Na as the reducing agent. The niobium particle size greatly decreased from 0.7㎛ to 0.2 ㎛ as the amount of diluent increased. However if a higher surface area of powder is required, more diluents need to be used in the said method in order to produce niobium powder. The niobium powder morphology and particle size are very sensitive to a amount of sodium excess. The particle size of niobium powder increased with a increasing amount of sodium excess. When more diluent and sodium are used, the niobium powder will be contaminated with more impurities such as Fe, Cr, Ni so on.

MR-EMR 복합제조공정에서 환원제 위치가 탄탈륨 분말 특성에 미치는 영향

박형호,윤재식,배인성,김양수,윤동주,원대희,김병일,Park, Hyeoung-Ho,Yoon, Jae-Sik,Bae, In-Sung,Kim, Yang-Soo,Yoon, Dong-Ju,Won, Dae-Hee,Kim, Byung-Il 한국분말야금학회 2007 한국분말재료학회지 (KPMI) Vol.14 No.3

A process known as the MR and EMR combination process is able to overcome the shortcomings of the MR (metallothermic reduction) and EMR (electronically mediated reaction) process. The effects of $K_2TaF_7$ as the raw material, sodium as the reducing agent and KCl/KF as the diluent on the characteristics of tantalum powder are investigated. In this study, a MR-EMR combination process has been employed to tantalum powder on the location of reductant. The excess of reductant were varied from 25, 50 to 75 wt%. The total charge and external circuit decreases as the amount of reductant increases. The average particle size increases with increasing the amount of reductant.

MR 및 EMR제조공정에 따른 탄탈륨분말 특성

박형호,윤재식,배인성,김양수,윤동주,원대희,김병일,Park, Hyeoung-Ho,Yoon, Jae-Sik,Bae, In-Sung,Kim, Yang-Soo,Yoon, Dong-Ju,Won, Dae-Hee,Kim, Byung-Il 한국분말야금학회 2007 한국분말재료학회지 (KPMI) Vol.14 No.3

In the metallothermic reduction (MR) process used to obtain tantalum powder in one batch, it is difficult to control the morphology and location of the tantalum deposits. On the other hand, an electronically mediated reaction (EMR) process is capable of overcoming this difficulty. The effect of using $K_2TaF_7$ as the raw material and sodium as the reducting agent on the characteristics of tantalum powder are investigated. As the temperature of the reduction varied from 1023K to 1223K, the powder particles obtained with MR were relatively large $({\sim}34{\mu}m)$, while those prepared via EMR were of uniform $(13{\mu}m)$. In the MR process, the Ta powder recovery rate increased from 37% to 83% at 1123K in constrat with EMR process.

지역별 목표강우량에서 강우지속기간의 적용성에 관한 고찰

안태진,윤재식,Ahn. Tae Jin,Yoon. Jae Sik 한국방재학회 2014 한국방재학회 학술발표대회논문집 Vol.2014 No.1

소방방재청(2011)은 도시방재성능의 달성을 위하여 1시간, 2시간 및 3시간 강우지속기간을 갖는 목표강우량을 전국 지자체별로 제시한 바 있다. 지자체별로 제시된 목표강우량은 각 지역에서 확보하여야 할 최소한의 방재성능에 대응되는 강우량으로 정의하였다. 유하시설의 설계는 1hr 지속기간 목표강우량을 추천하였고 저류시설 및 유역대책은 2hr 및 3hr 지속기간 목표강우량을 추천하였다. 소방방재청(2012. 8)에서 제시한 `도시방재성능 개선 지침`은 하수도시설의 하수 및 우수관거 지선, 간선 등, 빗물펌프장 시설, 저류지, 각종 우수유출저감시설과 같은 방재시설 등과 같은 내수배제를 위한 시설물을 대상으로 도시유역내 방재 시설물이 우수관거, 저류시설, 펌프장시설 등이 포함된 경우 시스템에 관한 통합적 방재성능을 평가하고 개선코자 할 때는 1시간, 2시간 및 3시간 강우지속기간 목표강우량 및 강우분포를 모두 적용하여 수계내 침수가 발생하지 않도록 대책을 수립토록 해야 한다. 본 연구에서는 서울 신천지구, 용산지구, 목포시 1개동, 수원시 2개동 및 평택시 3개동, 여수시 3개동에 관하여 임계지속기간 및 강우지속기간별 첨두유량의 변화에 대한 유하시설 설계를 위한 목표강우량의 타당성에 대하여 분석 하였다. 그 외 수원시 1개동의 수원종합운동장의 저류시설과 신천지구 저류시설을 통한 첨두유량의 변화 및 방재조절지 106개 지구의 임계지속기간과 저류용량과 저감되는 첨두유량과의 관계를 분석하여 지속기간 1hr, 2hr 및 3hr의 목표강우량의 타당성을 판단코자 하였다.

LED용 precursor 재이용을 위한 회수 및 정제 공정 개발

양재열,오병성,윤재식,Yang, Jae Yeol,O, Byung Sung,Yoon, Jae Sik 한국자원리싸이클링학회 2014 資源 리싸이클링 Vol.23 No.1

본 연구에서는 metal organic chemical vapor deposition(유기금속화학증기증착, MOCVD) 장치로 부터 LED용 GaN epi 성장 시원료로 사용되는 트리메틸갈륨에 대해서 사용 후 잔량을 회수하고 정제하여 재이용할 수 있는 공정 및 시스템을 개발하고자 한다. 본 공정에서 회수된 트리메틸갈륨에 대해서 화학적, 구조적 특성 평가를 통해서 재이용 가능여부를 검토하였다. 먼저 ICP-MS, ICPAES를 이용하여 순도를 분석한 결과 7N(99.99999%)의 고순도 트리메틸갈륨임을 확인했으며, NMR 분석을 통해서 트리메틸갈륨의 구조적 변화를 확인한 결과, 구조 변화 없이 순수 $(CH_3)_3Ga$(트리메틸갈륨) 구조임을 확인하였다. 또한 회수 트리메틸갈륨에 대한 신뢰성 검토를 위해서 MOCVD 공정을 이용하여 u-GaN를 증착시키고, 결정 특성 평가 및 광학 전기적 특성 평가를 실시하였으며 그 결과, 재이용이 가능함을 알 수 있었다. The purpose of this research is to develop a process and a system to collect, purify and reuse the residual quantity of trimethylgallium, used as a raw material, upon GaN epitaxial growth for LED from a metal organic chemical vapor deposition(MOCVD) equipment. This research reviews whether TMGa collected from the process can be used through a chemical and structural characteristics evaluation. As a result of analyzing the purity using ICP-MS and ICP-AES, 7N high purity (99.99999%) of TMGa was obtained. According to checking the structural change of TMGa through NMR analysis, TMGa having pure $(CH_3)_3Ga$ structure was obtained without structural change. For reliability review of the collected TMGa, u-GaN was deposited using the MOCVD process and an structural, optical and electrical characteristics evaluation was conducted. As a result, it was found out that the reuse was possible.