알콜 의존 환자에서 알콜 금단 후 혈장 베타 - 엔돌핀, 부신피질자극호르몬 및 코티졸의 변화

이동근,나철,손인기 大韓神經精神醫學會 2000 신경정신의학 Vol.39 No.3

연구목적 : 본 연구는 알코올 의존 환자에서 금주 상태가 시상하부-뇌하수체-부신축에 어떠한 기능 변화를 가져오는지를 알아보며, 이를 통해 알코올 의존의 원인 기전을 간접적으로 알아보기 위해 시행하였다. 방 법 : 알코올 의존 환자 14명에서 금주 후 7일과 28일에, 그리고 건강 대조군 14명에서 각각 오전 8시와 12시에 혈장 베타-엔도르핀, 코티졸, 부신피질자극호르몬의 농도를 측정하였다. 결 과 : 1) 금주 후 7일째 환자군과 대조군에서 오전 8시와 12시에 측정한 베타-엔도르핀, 코티졸, 부신피질자극호르몬은 서로 유의한 차이가 없었다. 2) 금주 후 28일째 환자군과 대조군에서 오전 8시에 측정한 베타-엔도르핀은 환자군이 대조군보다 유의하게 높았다. 그러나, 12시에 측정한 베타-엔도르핀은 유의한 차이가 없었으며 코티졸, 부신피질자극호르몬 오전 8시, 12시 모두에 유의한 차이가 없었다. 3) 금주 기간의 경과에 따른 변화를 볼 때, 환자군에서 오전 8시에 측정한 베타-엔도르핀, 코티졸, 부신피질자극호르몬은 금주 7일째와 28일째간에 유의한 차이가 없었으며, 12시에 측정한 부신피질자극호르몬에도 유의한 차이가 없었다. 그러나 12시에 측정한 베타-엔도르핀과 코티졸은 금주 후 7일째보다 금주 후 28일째에 유의하게 낮았다. 4) 일중 변동률의 차이를 보면, 오전 8시부터 정오 12시까지의 베타-엔도르핀의 감소속도가 금주 후 28일재 환자군에서 금주 후 7일째 환자군과 대조군보다 월등히 빨랐다. 결 론 : 알코올 의존 환자에서 금주기간이 길어지면 점차 혈장 내 베타-엘돌핀 농도가 감소하고, 일중 감소 속도도 증가하여 결과적으로 알코올 섭취 욕구가 증가된 것으로 생각되며, 이는 알코올 의존의 원인으로 오피오이드 보상가설을 지지하는 소견이다. Objectives : The present study was performed to evaluate the change in releasing action of hypothalamus-pituitary-adrenal axis after alcohol abstinence in patients with alcohol dependence, and to identify the etiologic mechanism of alcohol dependence indirectly. Methods : Plasma beta-endorphin, cortisol and ACTH level was measured in 14 alcohol dependent patients and in 14 healthy persons after 7 days and 28 days of alcohol abstinence at 08 : 00h and 12 : 00h, twice a day. Results : 1) There was no significant difference in plasma beta-endorphin, cortisol and ACTH level measured at 08 : 00h and 12 : 00h between patients and control group after 7days of alcohol withdrawal. 2) Plasma beta-endorphin level measured at 08 : 00h in patients was significantly elevated comparing with control group after 28days of alcohol withdrawal. But, there was no significant difference in plasma beta-endorphin level measured at 12 : 00h and in plasma cortisol and ACTH level measured at both 08 : 00h and 12 : 00h between two groups after 28days of alcohol withdrawal. 3) In the patient group, there was no significant difference between patients after 7days and 28days of alcohol withdrawal in plasma beta-endorphin, cortisol and ACTH level measured at 08 : 00h and ACTH level measured at 12 : 00h. But, beta-endorphin and cortisol level measured at 12 : 00h were significantly lowered in patients after 28days of alcohol withdrawal than after 7days of withdrawal. 4) In decreasing rate of beta-endorphin production from 08 : 00h to 12 : 00h, there was significant difference between patients and controlled group after 28days of alcohol withdrawal. Conclusion : In alcohol dependent patients, lower level of beta-endorphin and increased reducing rate in diurnal variation of beta-endorphin after alcohol withdrawal are evident, which in turn may elevate craving for alcohol intake, and there findings support the opioid compensation theory in the development of alcohol dependence.

Shaphylococcus enterotoxin B와 lipopolysaccharide를 작용시킨 사람 섬유아 세포에서 생성된 Transforming Growth Factor-β₁의 정량적 분석

이성근,김광혁,김욱규,김종렬,정인교,양동규 대한악안면성형재건외과학회 2000 Maxillofacial Plastic Reconstructive Surgery Vol.22 No.2

TGF-β1 is a potent chemotactic factor for inflammatory cells and fibroblasts. It also stimulates the celluar source and components of extracellular matrix and the production of proteinase inhibitors. Collectively, these biologic activities lead to the accumulation and stabilization of the nascent matrix, which is vital to infection control. The objective of this study is to investigate production of TGF-β in vitro fibroblast culture in the presence of Staphylococcus enterotoxin B(SEB) and/or lipopolysaccharide(LPS) and to elucidate the role of TGF-β1 which may be responsible for infection control. The fibroblasts were originated from gingiva and facial dermis in 26 year-old male patient. In the presence of LPS(0.01㎍, 0.1㎍, 1.0㎍), SEB(0.01㎍, 0.l㎍, 1.0㎍) respectively, cells(5×103ml) were cultivated in vitro. At 1, 3, and 5 days after incubation, cells were counted. Also, cells(2.5×105ml) were cultivated in EMEM with LPS(0.01, 0.1 and 1.0㎍), SEB(0.01, 0.1 and 1.0㎍) respectively and LPS(0.1㎍) and SEB (0.1㎍) in combination for 24,48, and 72 hours respectively. Culture supernatants were harvested at 1, 2, and 3 days after incubation period and triplicate culture supernatants were pooled and TGF-β1 was assayed in duplicate. The results were as follows. 1.In gingival fibroblast induced with SEB and LPS respectively or in combination, the suppression of cell Proliferation occurred very significantly since 3 days after incubation, compared with the control and the production of TGF-β1 occurred very significantly at 1 day after incubation, compared with the control. 2.In facial dermal fibroblast induced with SEB and LPS respectively or in combination. the suppression of cell proliferation occurred very significantly at 1 day after incubation, compared with the control. In SEB exposure, the production of TGF-β1 was decreased very significantly at 1 day after incubation, compared with the control. However, in LPS, SEB and LPS exposure, the production of TGF-β1 was increased very significantly at 1 day after incubation, compared with the control. In conclusion, the concentration of bacterial toxins and the incubation period correlated with cell proliferation and production of TGF-β1 very significantly. The gingival and facial dermal fibroblasts have different phenotype each other The orchestrated understanding of fibroblast proliferation and TGF-β1 production play an important part in host defense against the bacterial Infection and may prevent tissue necrosis such as necrotizing fasciitis and life-threatening syndrome such as multiple organ failure.

자란,풍란 및 나도풍란의 기내 종자발아에 관한 연구

김형근,강훈,소인섭 濟州大學校 亞熱帶農業硏究所 1999 亞熱帶農業硏究 Vol.16 No.-

우리나라 자생란인 자란의 기내파종시 적절한 소독방법과 적정배지 및 순화시 생존율을 높이기 위할 목적으로 uniconazole를 처리하고, 풍란과 나도풍란의 기내파종시 발아율을 높이기 위해 천연사과쥬스를 처리한 결과는 다음과 같다. 1. 자란의 기내파종시 종자를 Wilson 용액으로 소독하여 MS 혹은 Hyponex 3g/L 기본배지에 peptone 4g/L 배지에 파종하였을 때 발아와 생장이 가장 좋았다. 2. 기내 파종후 자란의 생장을 억제하기 위하여 uniconazole을 처리한 결과 활성탄 2g/L와 uniconazole 0.01mg/L를 첨가한 처리에서 초장이 넓은 타원형으로 알맞게 억제되었고, 활성탄이 첨가되면 uniconazole 이 활성탄에 흡수되어 억제효과가 다소 적어 활성탄을 첨가하지 않은 처리는 첨가한 처리보다 심하게 억제되었다. 3. 풍란의 기내파종시 Hyponex 3g/L 배지에서는 발아 후 생장이 전혀 이루어 지지 않았고 MS배지에서는 발아만 하였으나, Hyponex 3g/L에 천연 100% 사과쥬스를 첨가한 처리에서는 pH에 관계없이 전처리에서 발아하여 NAA 1mg/L에 활성탄을 첨가한 처리에서 발아와 생장이 가장 좋았다. 4. 나도풍란의 종자 발아와 생육에 대한 배지의 적용성은 풍란의 경우와 유사한 경향을 보여주었다. pH 5.8에 활성탄을 첨가하지 않고 NAA를 1mg/L 첨가한 처리만 발아 후 생장을 하였다. 발아와 생장이 잘된 배지는 Hyponex 3g/L에 천연 사과 주스 100ml/L를 첨가한 처리였으며 PH와 활성탄 및 NAA의 첨가에 관계없이 발아와 생장이 왕성했다. In order to find proper media, accurate sterilizing method and further growth on in vitro-seeding of Bletilla striata, korean native orchid, the uniconazole were treated. And the Neofinetia falcata and Aerides japonicum were treated with natural apple juice to improve germination ratio in vitro-seeding. The results obtained were as follows : 1. Germination and growth of Bletilla striata were the highest in case of seeding to MS or Hyponex 3g/L + peptone 4g/L media after sterilized them by Wilson's solution. 2. The results to promote growth of Bletilla striata after in vitro-seeding were that leaf shape was properly restrained widely ellipse in treated with 2g/L activated charcoal and 0.01mg/L uniconazole, and the treatment of uniconazole was more restrained than the treatment of activated charcoal. 3. In vitro-seeding of Neofinetia falcata, growth after germination was not affected in Hyponex 3g/L media and a little growth is shown in MS media. But in treatment which apple juice 100 ml/L was treated with Hyponex 3g/L, sprouting is shown in every treatments regardless of pH, and the total growth of seedlings is the best in the treatment of activated charcoal 2g/L and NAA 1mg/L. 4. In case of seeding of Aerides japonicum, germination rate and growth were similar trend to Neofinetia falcata. In every treatments of MS media, germination is a little bit, but further growth after germination was shown in treatment which treated NAA 1mg/L and pH 5.8 without activated charcoal. The best germination and growth media for 2 examined seeds were the treatment which apple juice 100 ml/L was treated with Hyponex 3g/L, but there was no effect on pH level, activated charcoal and NAA.

세균독소로 자극시킨 사람 섬유아 세포에서의 Interleukin-6와 Interleukin-8의 생성

정인교,양동규,홍시영,이성근,김욱규,김광혁,김종렬 大韓顎顔面成形再建外科學會 1999 Maxillofacial Plastic Reconstructive Surgery Vol.21 No.4

Cytokines are hormone-like proteins which mediate and regulate inflammatory and immune responses. Interleukin-6 (IL-6) is involved in the final differentiation of B cells into antibody-producing cells. Interleukin-8 (IL-8) is a neutrophil chemotactic factor that plays an important role in the recruitment of neutrophil to inflammatory loci. Inflammatory mediators by cells in the gingiva have been implicated in the initiation and progression of periodontitis and oral infection. The purpose of this study was conducted to investigate the effect of lipopolysaccharide (LPS), staphylococcus enterotoxin B (SEB) on production ofIL-6 and IL-8 by human gingival and facial dermal fibroblasts. Primary cultured human gingival and facial dermal fibroblasts were incubated with LPS(0.01, 0.1, 1.0㎍/ml), SEB (0.01, 0.1, 1.0㎍/ml) or LPS (0.1㎍/ml) plus SEB (0.1㎍/ml). Culture supernatants were collected at 24, 48, and 72 hrs and assessed for IL-6 and IL-8 production by enzyme-linked immunosorbent assay. IL-6 production in gingival fibroblasts stimulated with LPS was higher than that with SEB. IL-6 production by double exposure with LPS plus SEB was amplified in comparison with single exposure of LPS or SEB. IL-6 production in facial demal fibroblasts was increased only by stimulation with a high concertration of LPS (1.0㎍/ml). Its production in facial dermal fibroblasts by exposure with SEB was decreased in comparison with control, nontreated cells. Therefore, gingival fibroblasts showed higher sensitivity than facial dermal fibroblasts in response to low concentration of LPS. Also, IL-6 production by double exposure with LPS plus SEB was amplified in comparison with single exposure of LPS or SEB.IL-6 production in facial dermal fibroblasts was increased only by stimulation with a high concentration of LPS(1.0㎍/ml). Its production in facial dermal fibroblasts by exposure with SEB was decreased in comparison with control, nontreated cells. Therefore, gingival fibroblasts showed higher sensitvity than facial dermal fibroblasts in response to low concentration of LPS. Also, IL-6 production by double exposure with LPS plus SEB was amplified in comparison with single exposure of LPS or SEB. IL-8 production in gingival fibroblasts was enhanced greatly only by stimulation of high concentration of LPS (1.0㎍/ml). That by exposure with SEB was increased only in 24 hrs cultivation. IL-8 production by double exposure with LPS plus SEB was amplified in comparison with single exposure of LPS or SEB. IL-8 production in facial dermal fibroblasts was decreased by LPS and increased only in 48 hrs cultivation by SEB. IL-8 production by double exposure with LPS plus SEB was enhanced only in 48 hrs cultivation in comparison with single exposure of LPS or SEB. therefore, IL-6 and IL-8 production were released at various quantities according to bacterial toxin applied and site of fibroblast harvested. These results suggest that gingival fibroblasts may be concerned with IL-6 and IL-8 related inflammatory response more than facial dermal fibroblasts.

The Impact Analysis of Urban Growth on the Environment using the Econometric Regional Impact Model

JunHo Yeo,Jung-In Lee,Jae-Geun Park 한국환경정책평가연구원 2005 한국환경정책평가연구원 연구보고서 Vol.2005/re-07 No.-

빠르게 변화하는 기술 및 인구통계, 중앙정부 및 지자체의 정책, 그리고 세계화의 영향 등은 지역 정책 입안자들로 하여금 지역 경제와 환경에 대한 정확한 정보 파악을 필요로 하고 있으며, 지역 경제 체계에 대한 상황에 맞는 정보의 필요성이 높아지면서 지역사회에 대한 영향을 측정할 명쾌한 모델 개발이 중요하게 되었다. 그러나 국내의 경우, 각 도시별로 미래 경제성장이 인구나 환경변수들에 미치는 영향에 대해서 구체적으로 계량화한 연구나 자료가 없는 실정이어서 총생산량 증가와 밀접한 관계가 있는 도시별 총고용량 증대, 즉 경제성장이 환경부문에 미치는 영향을 계량화할 분석방법에 대한 연구가 필요하였다. 이러한 필요성을 바탕으로, 본 연구에서는 국내의 주요도시별로 고용량의 변화가 환경변수(아황산가스 오염도, 이산화질소 오염도, 생활폐기물 발생량, 공장폐수 방출량)와 기타 인구, 경제변수들에 미치는 영향을 평가하였다. 분석방법으로는 투입산출모델(Input-Output Model)의 단점을 보완할 수 있는 연립방정식모델(Simultaneous Equation Model)을 이용하였고, 실제 영향분석을 위해서 추정된 연립방정식모델을 유도형방정식(Reduced Form Equation)으로 전환하여 분석에 이용하였다. 분석결과를 요약해 보면 다음과 같다. 7대 도시의 취업자수 평균 증가율은 29.94%이고 광주가 35.81%로 최고의 증가율을 보이고 부산이 21.97%로 최저의 증가율을 보이는 것으로 추정되었다. Impact analysis 결과 고용증대가 인구나 실업자 증가에는 별로 영향을 미치지 않고 노동 인구의 증가와 노동참여율에는 큰 영향을 미치는 것으로 나타났다. 고용량 증가가 SO2, NO2, 생활쓰레기 발생량, 공장폐수 방출량에 미치는 영향은 거의 없거나 아주 미미한 것으로 나타났다. 이러한 결과는 현실과도 부합되는 것으로 고용증대가 생활쓰레기 발생량이나 공장폐수 방출량에는 아주 미미한 증가효과를, 그리고 SO2 농도에는 아주 미미한 감소효과를 주는 것으로 나타났으나 그 효과는 극히 미미함을 알 수 있었다. 그러나, 본 연구에서 추정한 연립방정식모델로는 산업별 고용증대가 환경부문이나 노동시장부문에 미치는 영향을 파악하기가 어려운 점이 있다. 산업별 고용증대 효과를 분석하기 위해서는 외부 충격 변수로 전체 고용 증대가 아니라 특정한 산업의 고용증가를 이용해야 할 것이다. 또한 고용증대가 환경부문에 미치는 영향은 아주 미미한 것으로 나타났기 때문에 차후 연구에서는 도시의 GNP 성장이나 GDP 성장과 같은 변수들을 충격변수로 이용하여 분석해 보는 것도 의미있는 연구가 될 것으로 보인다. This study develops a regional econometric model to extend and complement standard local economic impact analysis for Korean cities. We use a static macroeconomic model to derive labor supply equations and environmental equations. The resulting empirical model is based on a cross- sectional econometric analysis of Korean cities. The use of the estimated econometric model is illustrated with a real job-growth scenario using the growth in jobs between 2000 and 2006 for each Korean city. We focus on the effect of job growth on the labor market, especially on the allocation of jobs between in-migration, in-commuting and the local resident labor force. The purpose of this research was to estimate the effect of employment changes between 2000 and 2006 on population, labor and the environment. In order to do this, we have determined the estimated value of the number of job holders in seven major cities in 2006 and added this to a reduced form equation as an external impact, to predict changes in the eight endogenous variables. It was estimated that the average increase number of the employed in the seven cities was 29.94%; Gwangju showed the highest increase rate of 35.81%, while Busan recorded the lowest, 21.97%. The results of impact analysis demonstrated that employment growth hardly affected population or affected a change in the number of unemployed, but it had a large influence on the labor force increase and participation rate. The employment growth had almost no effect on the amount of SO2, NO2, house wastes and factory wastewater. The results also accord with the actual situation, where employment growth caused a very minor increase in the amount of house wastes and factory wastewater, and a very slight decrease in the density of SO2; however, the effect was too little. Nonetheless, it is difficult to identify the effect of employment growth in each industry on the environment or labor market, by using the simultaneous equation model presumed in this research. In order to analyze the effect of employment growth by industry, the increase of employment in the relevant industry, rather than total employment growth, should be used as an external impact variable. Moreover, as the effect of employment growth on the environment has turned out to be insignificant, it will be meaningful to analyze the matter by using variables such as the GNP or GDP growth of a city as impact variables, in the future research.

운동 선수군의 MTHFR 유전자의 C667T 돌연변이에 미치는 영향

정인근 한국스포츠리서치 2004 한국 스포츠 리서치 Vol.15 No.6

Hypertension, Obesity and osteoporosis may be explained by genetic background as well as environmental factors. The purpose of this study was to investigate the relationship between a C667T polymorphism in the MTHFR gene and these clinical phenotypes in young men about 20 years and the interaction with physical activity as a environmental factor. A C667T polymorphism in the MTHFR guns was assayed for 61 healthy young men including 28 controls and 33 athletes. By association study. there were no significance in genotype and allele Frequencies of a C667T polymorphism in the MTHFR gene between controls and athletes, respectively (P>0.05). Also, this polymorphism was not significantly associated with any clinical parameters in our subjects (P>0.05). Thus, it is unlikely that a C667T polymorphism in the MTHFR gene may be useful as a genetic marker for the diagnosis of these clinical parameters. However, the allele distribution of this polymorphism was significantly different among ethnic groups studied(P<.05). Therefore, our results suggest that a C667T polymorphism in the MTHFR gene may be applicable as a genetic marker for studying ethnic background of various common diseases.

Theoretical and experimental analysis of the source resistance components in In0.7Ga0.3As quantum-well high-electron-mobility transistors

Lee In-Geun,Ko Dae-Hong,Yun Seung-Won,Kim Jun-Gyu,Jo Hyeon-Bhin,Kim Dae-Hyun,Tsutsumi Takuya,Sugiyama Hiroki,Matsuzaki Hideaki 한국물리학회 2021 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.78 No.6

Herein we describe theoretical and experimental analysis of the source resistance (Rs) components in In0.7Ga0.3As/ In0.52Al0.48As quantum-well (QW) high-electron-mobility transistors (HEMTs) on an InP substrate. First, we analytically modeled Rs using a three-layer formula, separately modeling the regions of the ohmic contact, the gate-to-source access, and the side-recessed regions. The resistances of the ohmic contact and access regions were analyzed in a distributed-network manner with two different transfer lengths, whereas the resistance associated with the side-recess region near the gate edge was modeled by using a lumped element. To verify the accuracy of the proposed Rs model, we fabricated two different types of transmission-line-method (TLM) test patterns as well as long-channel In0.7Ga0.3As/ In0.52Al0.48As QW HEMTs, and compared their measured and modeled Rs. The modeled Rs was in excellent agreement with the measured Rs from the recessed TLM patterns and the long-channel HEMTs. Since the widths of the ohmic contact to the heavily doped In0.53Ga0.47As capping layer and the gate-to-source access region were typically much greater than corresponding transfer lengths ( L T_cap and L T_barrier ), those distributed networks could be simplified to a lumped-element based one-layer model, revealing that the tunneling resistance ( R barrier ) through the In0.52Al0.48As barrier should be carefully considered to minimize the Rs of InxGa1− xAs QW HEMTs together with S/D contact resistances and LGS.

서울시 지하철 역사내 라돈의 농도분포

황인조,한근혁,최형욱,김동술,김신도 경희대학교 환경연구소 2001 環境硏究 論文集 Vol.10 No.-

The various existing situations like overpopulation, urbanization, industrialization, and heavy traffic volume in the Seoul metropolitan area have led to the air pollution problem, traffic problem, and increase in opportunities of residing underground place. So, recently in Korea, the residents using underground working place have been of great concerns on indoor air pollutants such as HCHO, radon, particulate matter, carbon monoxide. However, the studies on indoor air pollution have been not extensively conducted in Korea. Indoor radon is an odorless, colorless, tasteless, invisible, inert, and naturally occurring radioactive gas. And it has been known as one of the notorious carcinogens. The purpose of this study was to survey the concentration variations of radon in the subway stations located Seoul metropolitan area. Total of 216 subway stations were surveyed by the continuous radon monitors from Mar. 2001 to Jun. 2001. The study showed that average radon levels of concourses in each line were 1.51, 1.45, 1.51, 1.23, 1.28, 1.37, 1.12, 1.28 pCi/L and those of platforms in each line were 2.09, 1.43, 1.37, 1.67, 1.44, 1.54, 1.40, 1.22 pCi/L, respectively. The study results showed that the average radon concentrations were 1.19 pCi/L in outdoor, 1.34 pCi/L in concourse, and 1.52 pCi/L in platform, respectively.

서울의 Penicillinase Producing Neisseria gonorrhoeae 발생빈도(1997)

김재홍,문득곤,김정수,김용준,임동진,박상훈,김희성,이민수,송기훈,김갑형,김형석,성소영,이인섭,김석우,황지환,조창근,김경문,부태성 대한화학요법학회 2000 대한화학요법학회지 Vol.18 No.3

Background : In recent years, gonorrhea has been pandemic and remains one of the most common STDs in the world, especially in developing countries. Objective & Methods : For the detection of a more effective therapeutic regimen and assessing the prevalence of PPNG, we have been trying to study the patients who have visited the Venereal Disease Clinic of Choong-Ku Public Health Center in Seoul since 1980 by means of the chromogenic cephalosporin method. Results : In 1997. 99 strains of N. gonorrhoeae were isolated, among which 45(45.5%) were PPNG. Conclusion : The prevalence of PPNG in Seoul, which had been decreased to 39% in 1996 after a peak of 74.3% in 1993, is increased to 45.5% in 1997.

Development and Evaluation of a Thimble-Like Head Bolus Shield for Hemi-Body Electron Beam Irradiation Technique

Shin Wook-Geun,Lee Sung Young,진형민,Kim Jeongho,Kang Seonghee,Kim Jung-in,정성문 대한방사선방어학회 2022 방사선방어학회지 Vol.47 No.3

Background: The hemi-body electron beam irradiation (HBIe–) technique has been proposed for the treatment of mycosis fungoides. It spares healthy skin using an electron shield. However, shielding electrons is complicated owing to electron scattering effects. In this study, we devel- oped a thimble-like head bolus shield that surrounds the patient’s entire head to prevent irradia- tion of the head during HBIe–. Materials and Methods: The feasibility of a thimble-like head bolus shield was evaluated using a simplified Geant4 Monte Carlo (MC) simulation. Subsequently, the head bolus was manufac- tured using a three-dimensional (3D) printed mold and Ecoflex 00-30 silicone. The fabricated head bolus was experimentally validated by measuring the dose to the Rando phantom using a metal-oxide-semiconductor field-effect transistor (MOSFET) detector with clinical configura- tion of HBIe–. Results and Discussion: The thimble-like head bolus reduced the electron fluence by 2% com- pared with that without a shield in the MC simulations. In addition, an improvement in fluence degradation outside the head shield was observed. In the experimental validation using the in- house-developed bolus shield, this head bolus reduced the electron dose to approximately 2.5% of the prescribed dose. Conclusion: A thimble-like head bolus shield for the HBIe– technique was developed and vali- dated in this study. This bolus effectively spares healthy skin without underdosage in the region of the target skin in HBIe–.