Post-mastectomy radiation therapy in breast reconstruction: a patterns of care study of the Korean Radiation Oncology Group

Gowoon Yang,Jee Suk Chang,Kyung Hwan Shin,Jin Ho Kim,Won Park,Haeyoung Kim,Kyubo Kim,Ik Jae Lee,Won Sup Yoon,Jihye Cha,Kyu-Chan Lee,Jin Hee Kim,Jin Hwa Choi,Sung-Ja Ahn,Boram Ha,Sun Young Lee,Dong Soo 대한방사선종양학회 2020 Radiation Oncology Journal Vol.38 No.4

Purpose: The details of breast reconstruction and radiation therapy (RT) vary between institutions; therefore, we sought to investigate the practice patterns of radiation oncologists who specialize in breast cancer. Materials and Methods: We identified the practice patterns and inter-hospital variations from a multi-center cohort of women with breast cancer who underwent post-mastectomy RT (PMRT) to the reconstructed breast at 16 institutions between 2015 and 2016. The institutions were requested to contour the target volume and produce RT plans for one representative case with five different clinical scenarios and answer questionnaires which elicited infrastructural information. We assessed the inter-institutional variations in RT in terms of the target, normal organ delineation, and dose-volume histograms. Results: Three hundred fourteen patients were included; 99% of them underwent immediate reconstruction. The most irradiated material was tissue expander (36.9%) followed by transverse rectus abdominis musculocutaneous flap (23.9%) and silicone implant (12.1%). In prosthetic-based reconstruction with tissue expander, most patients received PMRT following partial deflation. Conventional fractionation and hypofractionation RT were used in 66.6% and 33.4% patients, respectively (commonest: 40.05 Gy in 15 fractions [17.5%]). Furthermore, 15.6% of the patients received boost RT and 53.5% were treated with bolus. Overall, 15 physicians responded to the questionnaires and six submitted their contours and RT plans. There was a significant variability in target delineations and RT plans between physicians, and between clinical scenarios. Conclusion: Adjuvant RT following post-mastectomy reconstruction has become a common practice in Korea. The details vary significantly between institutions, which highlights an urgent need for standard protocol in this clinical setting.

A New ATC (ATM Transfer Capability) for Non-Realtime VBR Service : NBR (Negotiated Bit Rate)

Gowoon Lee(이고운),ChangHwan Oh(오창환),Aftab. Ahmad,Ki Son. Kim(김기선) 한국정보과학회 1997 한국정보과학회 학술발표논문집 Vol.1997 No.4

Detection of homodimer formation of CD99 throughextracelluar domain using bimolecular fluorescencecomplementation analysis

Gowoon Choi, Sang Wook Lee,Kyoung Cheon Jung,Eun Young Choi 생화학분자생물학회 2007 Experimental and molecular medicine Vol.39 No.6

Although various functions of CD99 have been reported, such as apoptosis and homotypic aggregation of thymocyte and transendothelial migration of immune cells, biochemical/molecular natures of CD99 are still elusive. Using mouse CD99 gene, we show that CD99 forms homodimer through its extracellular domain. Expression of mouse CD99 is up-regulated on T cells after CD3-mediated activation, like the case for human CD99. The potential of CD99 to form homodimer was tested with a recently developed bimoleular fluorescence complementation analysis (BiFC). In BiFC analysis, the dimerization-induced fluorescence was strong near the perinuclear region and was faded at the cell membrane. However, surface expression of CD99 was still detected by flow cytometry, suggesting that CD99 either in monomer form or in association with other molecules exists on the cell surface. In BiFC analysis using CD99 mutants with its extracellular, transmembrane, or cytosolic domains changed to corresponding human CD4 domains, the mutant replaced with human CD4-extracellular domain did not produce fluorescence. Purified soluble CD99-Fc fusion proteins bound to CD99-Fc immobilized onto the gold sensor chip in surface plasmon resonance analysis, confirming that the extracellular domain was responsible for dimer formation. Intracytoplasmic staining for CD99 expression in the thymocytes and mature T cells showed that most of the cells, even the cells with low surface level of CD99, contained the molecule inside the cell. Our results suggest that majority of CD99 homodimers may exit in the cell and be exported to the cell surface, dissociating from each other, after a certain regulatory signal is delivered.

Effects of gemfibrozil on sex hormones and reproduction related performances of <i>Oryzias latipes</i> following long-term (155 d) and short-term (21 d) exposure

Lee, Gowoon,Lee, Sangwoo,Ha, Nayoung,Kho, Younglim,Park, Kyunghwa,Kim, Pilje,Ahn, Byeongwoo,Kim, Sunmi,Choi, Kyungho Academic Press 2019 Ecotoxicology and environmental safety Vol.173 No.-

<P><B>Abstract</B></P> <P>Gemfibrozil, a lipid-regulating pharmaceutical, has been widely used for treating dyslipidemia in humans and detected frequently in freshwater environments. Since plasma cholesterol is a precursor of steroid hormones, the use of gemfibrozil may influence the sex hormone balances. However, its endocrine toxicity following long-term exposure is not well understood. The purpose of the present study is to investigate the effects of gemfibrozil on sex hormones and reproductive outcomes in a freshwater fish, following a long-term (155 d) exposure. For this purpose, Japanese medaka embryos (F0) were exposed to a series of gemfibrozil concentrations, i.e., 0, 0.04, 0.4, 3.7, and 40 mg/L for 155 d, and reproductive parameters, sex hormones, and associated gene expressions were assessed. For comparison, a short-term exposure (21 d) was performed separately with adult medaka and measured for sex hormones and related gene expressions. Following the 155 d long-term exposure, the fecundity showed a decreasing pattern. In addition, at 3.7 mg/L gemfibrozil, testosterone (T) level in the female fish was significantly decreased, and the hatchability of F1 fish was significantly decreased. The <I>estrogen receptor</I> (<I>er)</I> or <I>vitellogenin</I> (<I>vtg)</I> genes in gonads and liver were up-regulated. However, plasma cholesterol levels did not show significant changes in both sexes. The observations from the short-term (21 d) exposure were different from those of the long-term exposure. Following the short-term exposure, decreased 17β-estradiol (E2), and 11-ketotestosterone (11-KT) levels along with decrease plasma cholesterol were observed in the male fish. The hormone disruption following the short-term exposure appears to be associated with the hypocholesterolemic activity of gemfibrozil. Our results show that the mechanisms of gemfibrozil toxicity may depend on the exposure duration. Consequences of long-term exposure to other fibrates in the water environment warrant further investigations.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Exposure to gemfibrozil led to sex hormone and reproduction changes in fish. </LI> <LI> Changes in steroidogenesis and cholesterol levels were different by exposure duration. </LI> <LI> Long-term (155 d) exposure from embryo stage caused weak estrogenic responses. </LI> <LI> Short-term adult exposure caused decreased E2 levels. </LI> </UL> </P>

물 환경 잔류 의약물질 혼합노출에 따른 생태독성의 연구 동향

이고운(Gowoon Lee),이새람(Saeram Lee),지경희(Kyunghee Ji),김필제(Philje Kim),최경호(Kyungho Choi) 서울대학교 보건환경연구소 2012 보건학논집 Vol.49 No.2

영화에서의 음악적 의미와 분석

이고운(Gowoon Lee),이승연(Seungyon-Seny Lee) 한국콘텐츠학회 2017 한국콘텐츠학회 종합학술대회 논문집 Vol.2017 No.5

뉴노멀 시대 중소기업의 대외경쟁력 제고를 위한 정책과제 연구

이승신(LEE Seunshin),이현태(LEE Hyuntae),나수엽(NA Suyeob),조고운(CHO Gowoon),오윤미(OH Yunmi),이준구(LEE Jungoo) 대외경제정책연구원 2016 연구보고서 Vol.16 No.01

한국과 대만의 중소기업은 매우 유사한 문제점을 안고 있다. 양국 모두 국내 시장이 협소하고, 자국 내 중소기업의 입지가 좁은 편이다. 따라서 양국 기업의 대부분을 차지하는 중소기업의 활로는 해외시장 진출에 있다고 할 수 있다. 특히 기업 생산활동이 국제적으로 다양화되는 상황을 고려할 때 중소기업의 글로벌 가치사슬(GVC) 참여를 통한 해외진출은 매우 중요하다. 수출 데이터로 본 양국 중소기업의 직접수출은 글로벌 금융위기 이후 세계 경제 성장이 둔화되는 가운데 전체 수출에서 차지하는 비중이 축소되고 있다. 그러나 생산과정이 복잡해진 지금 직접수출비중 축소가 중소기업의 해외 경쟁력 저하를 의미한다고 볼 수는 없다. 본 보고서에서는 많은 중소기업이 대기업 가치사슬을 통해 간접수출을 하고 있음에 주목하고, 이를 포함한 한국과 대만 중소기업의 전체 수출비중을 계산하고 비교하였다. 그 결과 대만 중소기업의 간접수출비중은 크게 증가하고 있는 반면 한국 중소기업의 간접수출비중은 큰 변화가 없었다. 이는 대만 중소기업의 전체 수출비중은 증가하지만 한국 중소 기업의 전체 수출비중은 하락하는 결과로 이어졌다. 이 결과는 양국의 산업구조 변화와 중소기업과 대기업의 GVC 참여 상황 변화로 설명할 수 있다. 2000년대 대만의 급속한 대기업화는 중소기업이 대기업에 수출용 중간재를 공급하는 구조를 강화하면서 중소기업의 간접수출비중을 늘렸다. 반면 한국은 대기업 위주의 수출구조 및 수직계열화 구조가 계속 유지되면서 중소기업과 대기업 간 GVC 관계가 심화되지 못했기에, 2000년대 총수출 증가가 중소기업 수출비중을 늘리는 방향으로 이어지지 못했다.휴대폰 산업의 한 · 대만 GVC 참여상황 분석에서도 이러한 특징이 뚜렷이 나타난다. 한국과 대만은 휴대폰 산업의 GVC 참여 형태가 다르다. 한국은 대기업이 가치사슬을 대부분 내부화시켰고 최종 브랜드 생산에 직접 임하고 있지만, 대만은 다수의 중소기업이 중저가 위주의 표준화된 부품분야에서 주로 다국적기업과 가치사슬로 연결되어 있다. 이런 구조하에서 한국 중소기업은 대만 중소기업에 비해서 GVC에 직접 연결되어 세계시장 참여도를 높이거나 고부가 가치 영역을 개척하기가 쉽지 않았다. GVC에 성공적으로 진입한 대만과 한국 중소기업의 사례를 종합해보면 몇 가지 시사점을 발견할 수 있다. 첫째, 다국적기업에 부품을 납품하거나 OEM,ODM으로 해외 주문을 수주하는 등 다양한 GVC 진입 방법이 있으나, 이런 글로벌화의 성공을 위해서는 중소기업 자체의 기술력이 바탕이 되어야 한다는 것이다. 또 이를 위해서는 R&D 투자를 지속적으로 늘리고 연구 인력을 꾸준히 보강하는 노력이 필수적이었다. 둘째, 능동적 수요 대응이다. GVC에 성공적으로 진입한 대만기업들은 해외시장을 적극적으로 개척하고 해외 바이어의 니즈에 선도적으로 대응한 공통점을 가지고 있다. 셋째, 적극적인 해외투자 전략이다. 시장 개척 및 현지화, 저비용 생산요소 획득 등의 목표를 위해 이들 기업들은 중국, 동남아 등에 적극적으로 생산 공장이나 판매망을 구축하였다. 특히 시장 상황이 좋지 않을 때에도 적극적인 해외투자를 통해 생산능력을 확충하여 이후 호황기에 늘어난 수요량을 공급하면서 시장점유율을 높여나갔다. 대만 중소기업 GVC 참여 성공 사례에서 볼 때 정부의 역할은 산업화 초기 FDI 등을 통해 다국적기업을 적극 유치함으로써 대만기업과의 기업 생태계를 형성시킨 것으로부터 시작된다. 많은 대만 중소기업인들이 이런 다국적기업에서 일하면서 기술과 경험을 익혔고, 이때 형성된 국제 네트워크를 통해 지속적으로 다국적기업들과 OEM, ODM 관계를 지속시켜 나갈 수 있었다. 또한 경제부 기술처 등은 중소기업이 첨단 생산관리시스템을 개발 구축하는 것을 적극 지원하였고, 정부가 주도한 기초과학 연구 성과를 공유시켜서 기업이 R&D와 후속 응용기술 개발에 활용할 수 있게 지원하였다. 한국 중소기업 사례의 성공요인에서도 지속적인 R&D 투자, 시장수요 예측 및 신속대응, 글로벌 네트워킹 등 공통적인 특징을 볼 수 있다. 우리나라와 대만의 중소기업 해외진출 지원정책의 내용은 중소기업 역량 강화, 중소기업 수출지원센터 운영, 해외 네트워크 형성 및 활용 지원, 수출 인큐베이터 운영, 해외마케팅 확대 등 대체적으로 유사하다. 하지만 양국이 시행하고 있는 지원정책을 자세히 들여다보면 대만의 경우 우리와 달리 중소기업의 자생력 배양을 중점적으로 지원하고 있는 것으로 평가된다. 첫째, 중소기업 인큐베이션 센터의 운영이다. 한국의 경우 세계 주요 교역거점에 수출인큐베이터를 설치하고 저렴한 비용으로 사무공간을 제공하는 서비스를 제공하고 있다. Small and medium-sized enterprises (SMEs) in Korea and Taiwan share very similar problems; both suffer from relatively small domestic markets and limited positions in the respective markets. Therefore, the survival of SMEs in both Korea and Taiwan - which take up the largest portion in both economies 󰠏 depends on their capacity for increased overseas expansion. In today’s world where the production cycle of companies is becoming increasingly internationalized, the SMEs’ overseas expansion through participation in the global value chains (GVCs) becomes all the more important. Due to the economic recession, the direct exports of SMEs in proportion to the total direct exports are decreasing in both economies. But the complex production cycle of companies indicates that this does not necessarily point to a decrease in SMEs’ overseas competitiveness. This research focused on the fact that actually, many SMEs engage in indirect exporting by participating in value chains of major companies, and compared the total exports (including both the direct and indirect exports) of SMEs in Korea and Taiwan. The results showed that while the proportion of indirect exports to total exports in Taiwan SMEs has greatly increased over time, that of Korean SMEs has shown little difference. This has led the total exports of Taiwanese companies to increase while the total exports of Korean SMEs decreased. This phenomenon can be explained by two factors: the changes in the industry structures in the two countries and the changes in the participation rate of SMEs and major companies in GVCs. In the 2000s, the proportion of major companies in the Taiwanese economies grew rapidly, intensifying the relationship between major companies and SMEs, under which SMEs provided for the intermediate goods for exports to major companies. This practice increased indirect exports of Taiwanese SMEs. On the other hand, in Korea, major company-oriented export structure and vertical integration structure persisted, with no progress in the GVC relations between major companies and SMEs. This meant that the increase in Korea’s total exports in the 2000s did not lead to an increase in the total exports of Korean SMEs. These characteristics are clearly visible in the two countries’ cellular phone industry. The GVC structure in Korea and Taiwan differs very much in that for Taiwan, SMEs are more directly involved in the GVC than Korea. For SMEs in Korea, where major companies mostly internalized the value chains and are involved directly in the final brand production process, it is not easy for SMEs to engage in GVCs, or participate in the global market or a high value-added industry. Looking into the cases of SMEs that have successfully integrated into GVC in both Taiwan and Korea, we can derive several implications. First, although there exist multiple ways to enter GVCs such as supplying parts and components to a multinational company or procuring overseas contracts as OEM or ODM, in order for such trials to succeed, the SME in question must have a solid technological base. Long-term investment in R&D and research personnel are essential. Second, an active response to the demand is also integral for the company’s success. The SMEs who did succeed in entering overseas markets, actively respond to the foreign buyers’ needs. Third, active overseas investment strategy is also essential. Another common trait that these SMEs shared was that they all actively sought to build production factories or sales networks in China or Southeast Asia, where they can enjoy multiple benefits including obtaining a new market and low-cost factors of production. Taiwanese cases of SMEs who have successfully integrated into GVCs show that the government’s role in the beginning stage of industrialization is to attract multinational companies by utilizing measures like FDI.

우주 폭풍 연구를 위한 탑재체의 인터페이스와 중에너지 입자검출기의 운용

이채안(Chaean Lee),윤세영(Seyoung Yoon),서용명(Yongmyung Seo),우주(Ju Woo),설우형(Woohyung Seol),이찬행(Chanhaeng Lee),선종호(Jongho Seon),나고운(Gowoon Na),손종대(Jongdae Sohn),민경욱(Kyoungwook Min),강경인(Kyungin Kang),신구환(Goohwa 한국항공우주학회 2016 한국항공우주학회 학술발표회 논문집 Vol.2016 No.11

주기적 이동 노드를 위한 Delay-Tolerant Network 라우팅 알고리즘

이영세(Youngse Lee),이고운(Gowoon Lee),조항기(Hangki Joh),유인태(Intae Ryoo) 한국디지털콘텐츠학회 2014 한국디지털콘텐츠학회논문지 Vol.15 No.1

UV-기반 고도산화공정을 이용한 벤조페논-8의 분해

이영민(Young-Min Lee),이고운(Gowoon Lee),조경덕(Kyung-Duk Zoh) 대한환경공학회 2020 대한환경공학회 학술발표논문집 Vol.2020 No.11