고선량률 강내 근접치료에 사용되는 Ir-192 선원과 치료계획 시스템간의 계산선량 비교

박동욱,김영석,박성호,최은경,김종훈,이상욱,송시열,안승도,노영주,Park, Dong-Wook,Kim, Young-Seok,Park, Sung-Ho,Choi, Eun-Kyung,Kim, Jong-Hoon,Lee, Sang-Wook,Song, Si-Yeol,Ahn, Seung-Do,Noh, Young-Joo 한국의학물리학회 2009 의학물리 Vol.20 No.1

본 연구에서는 동일한 시스템 내에서 기하학적 모델이 다른 Ir-192 선원을 사용한 두 치료계획의 선량차이를 비교하고, 치료계획시스템 간 차이에 대해서 동일 선원을 사용할 경우 제조사별 프로그램 및 선원들의 위치결정방법에 따른 선량 계산결과의 차이와 그 영향을 평가하고자 하였다. 이를 위해 2007년 10월에서 2008년 1월까지 본 원에서 Ovoids와 Tandem을 이용하여 자궁경부암 근접치료를 시행 받았던 10명 환자의 치료계획에 대하여 적용하였다. 실제 환자에 적용된 치료계획을 바탕으로 평가한 결과 선원의 기하학적 특성의 차이로 발생할 수 있는 임상의 영향이 1.43% 이내로 전체 조사시간의 차이 및 B-point, 방광과 직장에서의 선량차이는 평균 $-0.91{\pm}0.09%$, $-0.27{\pm}0.07%$, $0.88{\pm}0.37%$, $0.22{\pm}0.39%$로 나타났다. 각 제조사별 프로그램에서 계산된 선량값들 간의 차이는 A-point, B-point, 방광 및 직장에서 평균 각각 $-0.22{\pm}0.42%$, $-0.25{\pm}0.29%$, $-0.23{\pm}0.63%$, $-0.17{\pm}0.76%$로 나타났다. 두 시스템에서 서로 다른 프로그램과 위치결정방법을 이용하여 계산한 각 치료계획의 선량분포 차이는 A-point, B-point, 방광 및 직장에서 평균 $-0.61{\pm}0.59%$, $-0.77{\pm}0.45%$, $-0.72{\pm}1.70%$, $0.35{\pm}2.82%$로 나타났다. 제조사별 프로그램상의 차이는 대체로 1.68% 이내, 직교좌표 상에서 선원의 경로좌표를 결정하는 방법론적인 차이에서는 치료계획자의 주관적인 판단이 더해져 최대 5.87% 가량의 선량계산결과 차이가 발생할 수 있음을 알 수 있었다. 또한 이러한 선원의 위치차이는 주로 환자의 AP방향에 위치한 직장과 방광의 선량에 더욱 민감하게 반영되었다. For HDR intracavitary brachytherapy with ovoids and a tandem, we compared the dose discrepancy of treatment plans using two different Ir-192 sources (microSelectron, Varian) and generated on two different treatment planning systems (PLATO, BrachyVision). The treatment plans of ten patient treated from Oct. 2007 to Jan. 2008 were selected for these comparisons. For the comparison of dose calculation using different sources, the average discrepancies were $-0.91{\pm}0.09%$, $-0.27{\pm}0.07%$, $0.22{\pm}0.39%$, and $0.88{\pm}0.37%$ in total treatment time and at B-point and ICRU bladder and rectum reference point, respectively. Comparing the two systems, the average dose discrepancies between treatment planning programs were $-0.22{\pm}0.42%$, $-0.25{\pm}0.29%$, $-0.23{\pm}0.63%$, and $-0.17{\pm}0.76%$, and the average dose discrepancies between positioning methods (PLATO with film and BrachyVision with digitial image) were $-0.61{\pm}0.59%$, $-0.77{\pm}0.45%$, $-0.72{\pm}1.70%$, and $0.35{\pm}2.82%$ at A-point, B-point, and ICRU bladder and rectum reference points, respectively. The rectal dose discrepancies between two systems were reached 5.87%. The difference in the dwell position expected by each TPS are mainly affected by the differences in the positioning method in TPSs and have an effect on dose calculations of rectal and bladder located in AP direction.

Validity of the Two-Mode Coupling Model in the Context of Cascaded Long-Period Fiber Gratings

박동욱,황준환,Park, Dong-Wook,Hwnag, Joon-Hwan The Institute of Electronics and Information Engin 2000 電子工學會論文誌-CI (Computer and Information) Vol.37 No.9

본 논문에서는 캐스케이드된 장주기 광섬유격자 구조의 해석에 기존의 두모드 결합 모델(TMCM)을 적용할 때에 발생하는 제한요인들에 대하여 분석하고, 아울러 이를 바탕으로 만족 시 TMCM 적용의 유효성을 보장하는 구체적인 조건들을 제안하다. 또한, 실제 상황에서 흔히 찾아 볼 수 있는 격자 파라메터 값을 적용하여 이와 같은 조건들이 의미하는 격자주기 변화의 허용범위와 사용가능 대역폭에 관하여 수치해석 결과를 갖고 논한다. This paper examines the constraints imposed in the usage of the conventional two-mode coupling model in the context of a cascaded long-period fiber grating and presents a set of approximate conditions that must be satisfied for the model to be applicable in the analysis of such a structure. Numerical examples based on the guidelines are provided for a set of realistic grating parameters and their practical implications on the allowed grating period variations for a given bandwidth are discussed.

인간자궁내막의 탈락막화 (Decudualization)에 있어서 TGF-$\beta$ (Transforming Growth Factor-$\beta$)의 역할

박동욱,최동순,김미란,황경주,조미영,안성희,민철기,유희석,Park, Dong-Wook,Choi, Dong-Soon,Kim, Mi-Ran,Hwang, Kyung-Joo,Jo, Mi-Yeong,Ahn, Seong-Hee,Min, Churl-K.,Ryu, Hee-Sug 대한생식의학회 2003 Clinical and Experimental Reproductive Medicine Vol.30 No.1

Objectives: To investigate the role of TGF (Transforming growth factor-$\beta$) involved in the paracrinic communication during decidualization between UEC (uterine epithelial cells) and USC (uterine stromal cells), we have employed a co-culture system composed of human endometrial epithelial and stromal cells in defined hormonal conditions. Design: In the co-culture, endometrial epithelial cells cultured in the matrigel-coated cell culture insert are seeded on top of the endometrial stromal cells cultured within a collagen gel. The co-culture was maintained for 48 hours under the following hormonal conditions: progesterone dominant condition (100 nM P4 and 1 nM E2) or estrogen-dominant condition (100 nM E2 and 1 nM P4). 10 ng/ ml HGF and/or 10 ng/ml TGF-$\beta$1 are added. Methods: RT-PCR is utilized to detect mRNAs quantitatively. Enzyme-linked immunosorbent assay (ELISA) and immunohistochemical staining are utilized to detect proteins in the tissue. Results: Prolactin mRNA is expressed in the co-cultured stromal cells under the progesterone dominant condition. TGF-$\beta$1 and its receptors are expressed in both the co-cultured epithelial and stromal cells irrespective of the steroid present, which is in contrast with no or negligible expression of TGF-$\beta$1 or its receptor in cells separately cultured. Both estrogen and progesterone significantly elevate the concentration of hepatocyte growth factor (HGF) in the conditioned medium of the co-culture with the value of 4, 325 pg/ml in E2-dominant and 2, 000 pg/ml in P4-dominant condition compare to 150 pg/ml in no hormone. In separately cultured stromal cells, administration of HGF induces the expression of TGF receptor 1 in both hormonal conditions, but induction of TGF receptor 2 is only manifest in the P4-dominant condition. Administration of TGF-$\beta$ and HGF directly induce the decidualization marker prolactin mRNA in separately cultured stromal cells. Conclusion: It is likely that steroid hormones induces prolactin mRNA indirectly by promoting the cell to cell communication between the stromal and the epithelial cells. TGF-$\beta$ and HGF are two possible paracrine mediators in the human endometrial decidualization.

인간의 착상 기전을 연구하기 위한 3차원적 자궁내막 모델 확립

박동욱,양현원,권혁찬,장기홍,김세광,조동제,오기석,Park, Dong-Wook,Yang, Hyun-Won,Kwon, Hyuck-Chan,Chang, Ki-Hong,Kim, Sei-Kwang,Cho, Dong-Jae,Oh, Kie-Suk 대한생식의학회 1999 Clinical and Experimental Reproductive Medicine Vol.26 No.1

In order to study the implantation mechanism various methods for culture of endometrial cells in vitro have been attempted. However, a disadvantage is that primary cultures of stromal and epithelial cells do not have the ability to differentiate, and therefore cannot be reproduced in the same manner as in vivo endometrium. The object of this study is to establish a three dimensional culture of endometrial cells which are both morphologically and functionally identical to in vivo endometrium. Endometrial tissues obtained after hysterectomies were cut into thin slices and treated with collagenase and trypsin-EDTA. The stromal cells and the epithelial cells were separated by centrifugation and cultured for 24 hours in DMEM media containing 10% FCS, 100 nM progesterone, and 1 nM estradiol. The cultured stromal cells were mixed with collagen gel and solidified, after which it was covered with matrigel. Epithelial cells were inoculated on the top and then cultured for 3 days. The three dimensionally cultured endometrial cells were stained for integrin ${\alpha}1,\;{\alpha}4,\;{\beta}3$, and cyclooxygenase-l, -2 by immunohistochemistry, which all showed strong expression. The cultured epithelial cells showed the formation of microvilli, tight junctions and pinopodes by electron microscopy. Studies are currently under way utilizing this three dimensional culture model to ascertain the interaction between the embryo and human endometrial cells at the time of implantation, and it is thought that further studies into a new culture environment which would allow longer periods of culture will be necessary.

인간 자궁내막에서 Cyclooxygenase-1과 -2의 주기적 발현 양상

박동욱,양현원,권혁찬,황경주,유정현,이치형,김세광,조동제,오기석,Park, Dong-Wook,Yang, Hyun-Won,Kwon, Hyuek-Chan,Hwang, Kyung-Joo,Yoo, Jung-Hyun,Lee, Chi-Hyeong,Kim, Sei-Kwang,Cho, Dong-Jea,Oh, Kie-Suk 대한생식의학회 1998 Clinical and Experimental Reproductive Medicine Vol.25 No.1

Cyclooxygenase (COX) is an enzyme involved in the conversion of arachidonic acid to prostaglandins (PGs), and exists in two forms, COX-1 and COX-2. COX has been reported to be involved in early implantation by secretion of PGs which causes permeability of vessels and reaction of decidual cells around the implantation site. Recently, in mice and sheep studies, COX-1 and COX-2 expression in the endometrium has been reported to be different according to implantation and stages of the estrous cycle, but expression of COX-1 and COX-2 in human endometrium during the menstrual cycle has not yet been established. The purpose of this study was to observe the variances of COX-1 and COX-2 expression by immunohistochemical staining in endometrial samples obtained from human hysterectomy specimens and biopsies of women of reproductive age according to different stages of the menstrual cycle. Also, we attempted to observe COX-1 and COX-2 expression in the epithelial and stromal cells of the endometrium obtained during the mid-secretory phase, which were cultured separately. COX-2 showed a cyclic pattern of expression according to the different stages of the menstrual cycle and was strongly expressed particularly at the mid-secretory phase which corresponds to the time of implantation. However, COX-1 tended to be increased in the early proliferative, and mid- and late secretory phases, but was also expressed in the whole menstrual cycle showing no particular pattern. In the separately cultured cells COX-1 was expressed in epithilial cells and COX-2 in the stromal cells. The above results suggest that since COX-2 is expressed at the same time as implantation and cultured cells display a specific secretory pattern, COX-2 has inductive endocrine enzyme properties and has an important effect on endometrial cells during implantation. Also, COX-2 expression in endometrial cells may be utilized as a useful marker of endometrial maturation.

분말 사출성형법으로 제조된 T42 고속도 공구강의 소결거동

박동욱,김혜성,권영삼,조권구,임수근,안인섭,Park, Dong-Wook,Kim, Hye-Seong,Kwon, Young-Sam,Cho, Kwon-Koo,Lim, Su-Gun,Ahn, In-Shup 한국분말야금학회 2012 한국분말재료학회지 (KPMI) Vol.19 No.2

Tool steels serve a large range of applications including hot and cold workings of metals and injection mouldings of plastics or light alloys. The high speed steels (HSS) are specifically used as cutting tools and wear parts because it has high strength, wear resistance and hardness along with appreciable toughness and fatigue resistance. From the view of HSS microstructure, it can be described as metallic matrix composites formed by a ferrous with a dispersion of hard and wear resistant carbides. The experimental specimens were manufactured using the PIM with T42 powders (50~80 vol.%) and polymer (20~50 vol.%). The green parts were debinded in n-hexane solution at $60^{\circ}C$ for 8 hours and thermal debinded at an $N_2-H_2$ mixed gas atmosphere for 8 hours. Specimens were sintered in high vacuum ($10^{-5}$ Torr) and various temperatures.

방전 플라즈마 소결법으로 제조한 T42 고속도 공구강의 기계적 특성 연구

박동욱(Dong-Wook Park),권용환(Yong-Hwan Gwon),김선민(Seon-Min Kim),권영삼(Young-Sam Kwon),조권구(Kwon-Koo Cho),안인섭(In-Shup Ahn) 한국생산제조학회 2011 한국생산제조시스템학회 학술발표대회 논문집 Vol.2011 No.4

Spark Plasma Sintering(SPS), that a recent innovation in rapid powder consolidation was used to fabricate T42 HSS alloy, which represents features of wear resistance, ductility and high hardness. The spark plasma sintering was carried out in the SPS machine under 3500㎏ㆍf/㎠ of 5×10-3Torr vacuum. All the sintered specimens were fabricated at 900, 1000 and 1100℃ for 10min and held at 1000℃ for maximum 30min, respectively achieved.

모 자동차 도장공정에서 사용한 신너의 성분과 공기중 노출에 관한 연구 : Ethylene Glycol Ethers류를 중심으로

박동욱(Dong Wook Park),임호섭(Ho Sub Lim),김신범(Shin Bum Kim),정다운(Da Wun Jung) 한국환경보건학회 1999 한국환경보건학회지 Vol.25 No.1

This study was conducted to identify components of thinners and to evaluate worker´s exposure to them in an auto manufacturing plant. Main components including Ethylene Glycol Ether were analyzed quantitatively as well as qualitatively. More than 18 components were analyzed qualitatively in 12 thinner samples. Toluene was the most frequently detected, and its amount ranged from 8.5% to 62.5%. 11 of 12 thinner samples have EGEE, EGEEA, and EGBE named Ethylene Glycol Ether. 23.7% of EGEE was included in C sample and 3.3 % in G sample. EGEEA was detected to 7.3% in D sample, and lower than 2.6 % in other 6 samples. Amount of EGBE was as much as 25.9% in G sample, 19.6% in E sample, 14.6% in A sample, and 11.3% in C sample. In addition to these components, a little amount of several components such as ketone, alchol, ether, and ester were also detected. But all thinner samples have not included benzene. Mixing room shows the highest concentration. Of several material included in thinner, worker´s exposure to toluene was 12.9 ppm in mixing room, and 3.3 ppm in third room which were higher than other components. Ethylene Glycol Ether detected in air was only EGEEA. Frequency of EGEEA detected in the air was as much as 90% in the mixing room and 40% in the third room. Worker´s average exposure to EGEEA was 2.4 ppm lower than TLV(5 ppm). In order to evaluate worker´s exposure in process using thinner, air sample to analyze toluene, xylene, benzene, Ethylene Glycol Ether, MIBK must be taken

Compression Hip Screw를 이용한 대퇴골 전자간 골절의 치료

박동욱(Park Dong Wook),김충오(Kim Chung O),안진환(Ahn Jin Whan),유명철(Yoo Myung Chul),김봉건(Kim Bong Kun) 대한정형외과학회 1979 대한정형외과학회지 Vol.14 No.2

논문 : 혜환 이용휴 열녀전의 입전 의식

박동욱 ( Dong Wook Park ) 한서대학교 동양고전연구소 2004 동방학 Vol.10 No.-