• Applied Biological Chemistry
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• 제43권3호
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• pp.179-183
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• 2000

감귤의 성숙과 저장 중에 일어나는 연화(softening)가 품질에 미치는 영향을 검토하기 위하여 궁천조생 온주밀감을 $3^{\circ}C$, 85% RH에서 저장하면서 저장 중 경도, 펙틴분해효소의 활성 등의 변화를 측정하였다. 저장기간이 경과함에 따라 부폐율은 저장 90일에 18.8%이었으며, 그 이후 급속히 증가하였다. 저장기간에 따른 중량감소는 24.5%까지 계속하여 완만하게 증가하였다. 경도는 2mm probe에서 538.9 g-force에서 336.9 g-force까지로 저장 중에 조금씩 감소하는 경향이었다. 수분 함량은 저장기간에 따라 과피에서 71.8%에서 72.6%까지로, 과육에서 90.3%에서 88.3%까지로 각각 약간 감소하였다. 성숙 중 경도는 1,176.8g-force에서 503.6 g-force로 급속히 감소하였고, 수분 함량은 과피와 과육이 각각 75.3%에서 74.9%로, 91.8%에서 90.7%로 약간 감소하였다. 세포벽 분해효소인 exo-polygalacturonase의 경우 저장 90일까지 과피에서는 326.0 units/100 g에서 534.9 units/100 g까지로, 과육에서는 63.1 units/100 g에서 81.0 units/100 g까지로 증가를 하다가 그 후 저장 150일까지 각각 394.0 units/100 g, 38.0units/100 g으로 감소하는 경향이었다. Pectinesterase 활성은 저장 60일까지 과피에서는 $14.4\;{\mu}mol$에서 $38.8\;{\mu}mol$까지로 증가하다가, 그 이후에 $6.0\;{\mu}mol$로 크게 감소하는 경향이었다. 과육에서는 저장 60일까지 $26.0\;{\mu}mol$에서 $39.0\;{\mu}mol$까지로 증가를 하다가 $8.2\;{\mu}mol$ 크게 감소하는 경향이었다.

• 헤리티지:역사와 과학
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• 제56권2호
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• pp.136-146
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• 2023

박제표본과 같은 생물학적 물질은 다양한 산이나 휘발성물질을 방출할 수 있다. 박제표본에 사용되는 보존제와 제작재료, 제작방법에 따라 발생하는 유기화합물의 방출 특성에 관한 연구는 전무한 실정이다. 따라서, 박제표본에서 발생하는 유기화합물을 알아보기 위해 재료별 표본, 수장고 표본을 대상으로 열화 실험하였다. 오계를 대상으로 나프탈렌과 붕사를 보존제로 사용하고, 대패톱밥, 신문지, 폴리스틸렌폼을 몸심재료로 사용하여 제작한 표본과, 동물수장고에서 수장하고 있던 오계 박제표본(2015년도)을 고온환경(50℃)과 고습환경(95%)에 각각 2주간 열화 실험하였다. 박제표본의 열화 실험결과 고습환경보다 고온환경에서 발생하는 유기화합물의 농도가 더 높은 경향을 보였다. 보존제로는 나프탈렌을 사용한 표본에서 벤젠, 톨루엔, 자일렌과 p-디클로로벤젠이 검출되어 나프탈렌이 주요 유기화합물을 방출하는 요인인 것을 확인할 수 있었고, 대패톱밥, 신문지, 폴리스틸렌폼을 사용한 표본에서도 유기화합물이 검출되 재료의 열화로 인한 것으로 보인다. 또한, 재료별 표본에서 암모니아가 검출되었는데 부패가 진행되어 검출된 것으로 보이며, 특히 고온열화에서 붕사를 사용한 표본이 나프탈렌을 사용한 표본보다 암모니아가 약 9배 높게 측정되었다. 이는 고온환경이 나프탈렌의 승화성을 가속시켜 살충·방충효과로 생물학적 피해를 예방한 결과라 판단된다. 나프탈렌은 발암 가능성 물질로 보존제로 사용할 경우 적정 사용관리가 필요하며, 박제표본은 제작기법에 따라 다양한 유기화합물이 방출할 수 있기 때문에 제작재료와 보존제 등의 조건에 따라 체계적인 보존관리방안이 필요한 것으로 사료된다.

• 대한환경공학회지
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• 제36권8호
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• pp.561-569
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• 2014

본 연구는 인제거를 위한 하수처리시설에서 발생하는 약품 잉여슬러지의 혐기성소화 특성을 조사하기 위한 것이다. 잉여슬러지의 최종생분해도 값은 Biogas발생량을 기준으로 약 31%, PACl 슬러지는 24%이며, Alum 슬러지는 26%이었다. 20일 동안 잉여슬러지는 $S_1$이 75%로써 $k_1$ ($0.1129day^{-1}$)의 속도로 분해되었으며, PACl 슬러지는 $k_1$ ($0.0998day^{-1}$)의 속도로 $S_1$인 74%의 BVS를 분해시켰고, Alum 슬러지는 $S_1$이 76%로써 $k_1$ ($0.1091day^{-1}$)의 속도로 분해되었다. SCFMR 반응조 운전시 모든 슬러지는 pH 6.7~7.0을, Alkalinity는 1,800~2,200 mg/L 범위로 차이가 미미하며 유사한 값을 유지하였다. HRT 20일에서 PACl 슬러지와 Alum 슬러지 Biogas 발생량은 각각 0.089, 0.091 v/v-d로 Control 0.124 v/v-d에 비해 낮은 27~28%이었다. 운전 전반에 걸처 메탄의 함량은 세 반응조 모두 70~76%로 PACl과 Alum을 주입함에 따른 영향은 없는 것으로 판단된다. PACl과 Alum을 주입한 슬러지의 TVS 제거효율은 HRT 20일에서 각각 평균 19.6%, 19.9%로 Control (23.8%)에 비해 약 4% 가량 작은 값을 나타내었으며, BVS 제거효율은 HRT 20일 조건에서 Control 반응조의 경우 평균 34.5%, PACl과 Alum 슬러지는 각각 평균 25.8%, 26.9%로 나타내어 PACl과 Alum 슬러지가 Control 보다 약 8% 낮은 제거효율을 보였다.

• 농약과학회지
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• 제12권1호
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• pp.67-73
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• 2008

실내에서 재배 중 살균제 boscalid의 생물학적 반감기를 계산하고, 생산단계 MRL 등을 제안하고자 오이에 boscalid를 살포하고 재배기간 중 잔류특성을 파악하였다. Boscalid 기준량 살포시 초기 잔류농도는 $7.29\;mg\;kg^{-1}$이며 15일 후에는 $0.04\;mg\;kg^{-1}$으로 감소되어 반감기는 1.9일 이었다. 배량 살포의 경우 초기농도 $14.69\;mg\;kg^{-1}$에서 15일 후에는 $0.11\;mg\;kg^{-1}$으로 감소되어 반감기는 2.0일 이었다. 그리고 배량 처리 시의 잔류감소 회귀식을 이용한 생산단계 농약잔류허용기준(PHRL)은 수확 10일전 $10.39\;mg\;kg^{-1}$ 또는 5일전 $1.76\;mg\;kg^{-1}$ 등으로 제안하였다. 또한 도출된 잔류감소 회귀식을 이용하여 약제 처리 후부터 MRL 이하로 잔류량이 감소하는 기간을 계산하였을 때, 기준량 처리 시 8.9일, 배량 처리 시 11.1일이 소요되는 것으로 나타났다. 오이 재배에 있어서 boscalid의 잔류량 감소 특성은 빠른 증체량에 따른 희석효과가 큰 기여를 한 것으로 나타났다. 감소 회귀식을 적용하여 boscalid 입상수화제를 안전사용기준에 따라 흰가루병 방제 및 잿빛곰팡이병 방제에 사용할 경우에 최종잔류농도를 예측해보면, 흰가루병의 경우 약제 처리 25일 후 기준량 처리 시 $1.26\;mg\;kg^{-1}$로 MRL($0.3\;mg\;kg^{-1}$)보다 높게 예상되었다. 또한 잿빛곰팡이병의 경우 약제처리 19일 후 최종잔류농도는 기준량 처리 시 $1.33\;mg\;kg^{-1}$로 역시 MRL보다 높게 예상되었다.

• 한국해양학회지:바다
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• 제3권4호
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• pp.234-248
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• 1998

동해의 해양투기장 해역에 버려진 폐기물이 환경에 미치는 영향을 조사하기 위해 동해 남부해역에 위치한 해양투기장 해역(정점 B, B')과 부산 동쪽의 외해에 위치한 해양투기장 해역(정점 J, J') 및 인근 지역(정점 J2, J6, H)에서 채취한 박스코아의 퇴적물에 함유된 유공충을 연구하였다. 유공충의 종다양성지수[S, H(S), E]와 부유성 및 저서성 유공충의 수는 해양투기장 해역과 인근 해역에서 차이를 보인다. 동해 남부해역에 위치한 해양투기장 해역 B와 B' 에서는 유공충의 종수가 작으며, 조립질 퇴적물의 양과 저서성 및 부유성 유공충의 수 또한 주변 해역에 비해 작은 값을 보인다. 부산 동쪽의 외해에 위치한 투기장 해역 J'에서는 인근의 다른 지역과는 다르게 비정상적으로 매우 많은 저서성(약 300,000 개체/10 g 건조시료) 및 부유성(약 300,000 개체/10 g 건조시료) 유공충이 나타난다. 아마도 투기된 폐기물이 영양분의 역할을 했을 것이다. J 해역은 B, B' 해역과 마찬가지로 다른 해역에 비해 상대적으로 낮은 종다양성지수[S, H(S)]를 보인다. 또한 J 해역의 코아 퇴적물에서는 저서성 유공충의 수가 코아 표층에서 코아 하부로 갈수록 감소한다. 이러한 사실은 J 해역이 스트레스를 받고 있는 환경임을 의미한다. J', J2, J6 해역은 매우 높은 종다양성지수[S, H(S)]를 보이는데, 이는 이들 해역이 매우 안정된 환경임을 의미한다. 투기장 및 인근 해역에서 병에 걸리거나 스트레스가 극심한 환경에서 나타나는 이상격실(abnormal chamber)을 가진 유공충은 발견되지 않았다. 또한 투기장 해역에 버려진 폐기물의 유기분해가 저층수를 부식성으로 바꿀만큼 강하지 않았다.

• 청정기술
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• 제28권1호
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• pp.63-78
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• 2022

첨단 전자산업 폐수 처리시설에서 발생되는 유기 폐수는 고농도의 유기물질 및 20가지 이상의 유독 난분해성 물질을 포함하고 있으며, 이를 효율적으로 처리하는 것은 첨단 전자산업의 당면 과제이다. 따라서, 첨단 전자산업 유기폐수 처리시설을 CPS (Cyber physical system)상 Water digital twin으로 구축하여 COD (Chemical Oxygen Demand), TN (Total Nitrogen), TP (Total Phosphorous) 및 TMAH (Tetramethylammonium hydroxide) 등 유기 오염물질의 제거 효율 평가가 가능한 전자산업 폐수 특화 모델 개발이 필요하다. 본 연구에서는 첨단전자산업 유기폐수 제거 메커니즘에 대한 분해 미생물의 성장과 사멸의 이론적인 반응속도식에 기반한 첨단 전자산업 폐수 특화 활성슬러지 모델(Electronics industrial wastewater activated sludge model, e-ASM)을 개발하였다. 개발한 e-ASM은 전자산업 폐수처리공정에서 발생하는 유기물 산화, 질산화, 및 탈질화 과정뿐만 아니라 TMAH 등 난분해성 유기물질의 분해과정 중 발생하는 질산화미생물의 저해(Inhibition) 작용 등 복잡한 생물학적 분해 메커니즘이 모사 가능하다. 이를 활용하여 실제 전자산업 유기폐수 처리시설을 Water Digital Twin으로 구현하여 CPS (Cyber physical system) 상에서 전자산업 폐수처리장에 폐수 유입 성상에 따라 공정 모델링, 유출수 예측, 공법 선정, 설계 효율 평가 등 다양한 목적으로 활용될 수 있다.

• 환경생물
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• 제40권4호
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• pp.455-463
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• 2022

기후변화에 따른 산림생태계의 기능 변화를 파악하기 위해 산림생태계의 중요한 기능인 낙엽분해율과 미기상 요인과의 상관관계를 분석하였다. 2017년 1월부터 48개월간 동사면과 서사면에 설치된 낙엽주머니를 통해 낙엽의 분해율을 분석하고 연구지소의 미기상요인(대기온도, 토양온도, 토양수분)을 관측하여 상관관계를 도출하였다. 48개월 경과 후 신갈나무 낙엽의 잔존율은 동사면과 서사면에서 각각 27.1±1.3%, 37.0±3.6%로 감소하였으며, 이에 따른 낙엽의 분해상수(k)는 동사면과 서사면에서 각각 0.33, 0.25로 나타났다. 신갈나무 낙엽의 초기 C/N비율은 38.5이었으며 시간이 경과함에 따라 감소하여 48개월 경과 후 동사면과 서사면의 C/N비율은 각각 13.4, 16.7로 나타났다. 연구지소의 조사기간 동안 평균 대기온도 및 토양온도는 동사면과 서사면에서 각각 8.2±9.0, 9.1±9.3과 8.5±7.4, 9.3±7.3℃로 서사면에서 더 높게 나타났다. 토양수분의 경우, 동사면과 서사면에서 평균 19.4±11.0, 20.5±5.7%로 큰 차이를 보이지 않았으나 연간 변화 양상이 다소 다르게 나타났다. 분석된 낙엽의 분해율과 미기상 요인과의 상관관계를 분석해본 결과, 동사면에서 낙엽분 해율과 토양수분이 양의 상관관계를 갖는 것으로 나타나, 낙엽분해율은 토양수분량에 영향을 받는 것으로 나타났다. 본 연구를 통해 향후 기후변화에 따른 폭우, 폭설 등의 영향이 산림생태계의 기능에 미치는 변화에 대응할 수 있는 기초자료를 제공하고자 한다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2004년도 총회 및 춘계학술발표회
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• pp.3-4
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• 2004

Results will be presented from two field studies that evaluated the in-situ treatment of chlorinated aliphatic hydrocarbons (CAHs) using aerobic cometabolism. In the first study, a cometabolic air sparging (CAS) demonstration was conducted at McClellan Air Force Base (AFB), California, to treat chlorinated aliphatic hydrocarbons (CAHs) in groundwater using propane as the cometabolic substrate. A propane-biostimulated zone was sparged with a propane/air mixture and a control zone was sparged with air alone. Propane-utilizers were effectively stimulated in the saturated zone with repeated intermediate sparging of propane and air. Propane delivery, however, was not uniform, with propane mainly observed in down-gradient observation wells. Trichloroethene (TCE), cis-1, 2-dichloroethene (c-DCE), and dissolved oxygen (DO) concentration levels decreased in proportion with propane usage, with c-DCE decreasing more rapidly than TCE. The more rapid removal of c-DCE indicated biotransformation and not just physical removal by stripping. Propane utilization rates and rates of CAH removal slowed after three to four months of repeated propane additions, which coincided with tile depletion of nitrogen (as nitrate). Ammonia was then added to the propane/air mixture as a nitrogen source. After a six-month period between propane additions, rapid propane-utilization was observed. Nitrate was present due to groundwater flow into the treatment zone and/or by the oxidation of tile previously injected ammonia. In the propane-stimulated zone, c-DCE concentrations decreased below tile detection limit (1 $\mu$g/L), and TCE concentrations ranged from less than 5 $\mu$g/L to 30 $\mu$g/L, representing removals of 90 to 97%. In the air sparged control zone, TCE was removed at only two monitoring locations nearest the sparge-well, to concentrations of 15 $\mu$g/L and 60 $\mu$g/L. The responses indicate that stripping as well as biological treatment were responsible for the removal of contaminants in the biostimulated zone, with biostimulation enhancing removals to lower contaminant levels. As part of that study bacterial population shifts that occurred in the groundwater during CAS and air sparging control were evaluated by length heterogeneity polymerase chain reaction (LH-PCR) fragment analysis. The results showed that an organism(5) that had a fragment size of 385 base pairs (385 bp) was positively correlated with propane removal rates. The 385 bp fragment consisted of up to 83% of the total fragments in the analysis when propane removal rates peaked. A 16S rRNA clone library made from the bacteria sampled in propane sparged groundwater included clones of a TM7 division bacterium that had a 385bp LH-PCR fragment; no other bacterial species with this fragment size were detected. Both propane removal rates and the 385bp LH-PCR fragment decreased as nitrate levels in the groundwater decreased. In the second study the potential for bioaugmentation of a butane culture was evaluated in a series of field tests conducted at the Moffett Field Air Station in California. A butane-utilizing mixed culture that was effective in transforming 1, 1-dichloroethene (1, 1-DCE), 1, 1, 1-trichloroethane (1, 1, 1-TCA), and 1, 1-dichloroethane (1, 1-DCA) was added to the saturated zone at the test site. This mixture of contaminants was evaluated since they are often present as together as the result of 1, 1, 1-TCA contamination and the abiotic and biotic transformation of 1, 1, 1-TCA to 1, 1-DCE and 1, 1-DCA. Model simulations were performed prior to the initiation of the field study. The simulations were performed with a transport code that included processes for in-situ cometabolism, including microbial growth and decay, substrate and oxygen utilization, and the cometabolism of dual contaminants (1, 1-DCE and 1, 1, 1-TCA). Based on the results of detailed kinetic studies with the culture, cometabolic transformation kinetics were incorporated that butane mixed-inhibition on 1, 1-DCE and 1, 1, 1-TCA transformation, and competitive inhibition of 1, 1-DCE and 1, 1, 1-TCA on butane utilization. A transformation capacity term was also included in the model formation that results in cell loss due to contaminant transformation. Parameters for the model simulations were determined independently in kinetic studies with the butane-utilizing culture and through batch microcosm tests with groundwater and aquifer solids from the field test zone with the butane-utilizing culture added. In microcosm tests, the model simulated well the repetitive utilization of butane and cometabolism of 1.1, 1-TCA and 1, 1-DCE, as well as the transformation of 1, 1-DCE as it was repeatedly transformed at increased aqueous concentrations. Model simulations were then performed under the transport conditions of the field test to explore the effects of the bioaugmentation dose and the response of the system to tile biostimulation with alternating pulses of dissolved butane and oxygen in the presence of 1, 1-DCE (50 $\mu$g/L) and 1, 1, 1-TCA (250 $\mu$g/L). A uniform aquifer bioaugmentation dose of 0.5 mg/L of cells resulted in complete utilization of the butane 2-meters downgradient of the injection well within 200-hrs of bioaugmentation and butane addition. 1, 1-DCE was much more rapidly transformed than 1, 1, 1-TCA, and efficient 1, 1, 1-TCA removal occurred only after 1, 1-DCE and butane were decreased in concentration. The simulations demonstrated the strong inhibition of both 1, 1-DCE and butane on 1, 1, 1-TCA transformation, and the more rapid 1, 1-DCE transformation kinetics. Results of tile field demonstration indicated that bioaugmentation was successfully implemented; however it was difficult to maintain effective treatment for long periods of time (50 days or more). The demonstration showed that the bioaugmented experimental leg effectively transformed 1, 1-DCE and 1, 1-DCA, and was somewhat effective in transforming 1, 1, 1-TCA. The indigenous experimental leg treated in the same way as the bioaugmented leg was much less effective in treating the contaminant mixture. The best operating performance was achieved in the bioaugmented leg with about over 90%, 80%, 60 % removal for 1, 1-DCE, 1, 1-DCA, and 1, 1, 1-TCA, respectively. Molecular methods were used to track and enumerate the bioaugmented culture in the test zone. Real Time PCR analysis was used to on enumerate the bioaugmented culture. The results show higher numbers of the bioaugmented microorganisms were present in the treatment zone groundwater when the contaminants were being effective transformed. A decrease in these numbers was associated with a reduction in treatment performance. The results of the field tests indicated that although bioaugmentation can be successfully implemented, competition for the growth substrate (butane) by the indigenous microorganisms likely lead to the decrease in long-term performance.

• Nuclear Medicine and Molecular Imaging
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• 제40권4호
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• pp.218-227
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• 2006

목적 : 헤르페스 심플렉스 1형 바이러스 티미딘 키나제(Herpes simplex virus type 1 thymidine kinase. HSV1-tk) 유전자는 보고 유전자로서 필요한 조건뿐만 아니라 별도의 치료 유전자를 따로 이입할 필요가 없다는 장점을 가지고 있어 유전자 영상과 치료에서 가장 널리 사용되는 유전자이다. 본 연구에서는 간암세포주에서 HSV1-tk 보고 유전자 발현을 비침습적 PET 영상으로 평가하는데 있어서 $9-(4-[^{18}F]Fluoro-3-hydroxymethylbutyl)$guanine ($[^{18}F]FHBG$)의 유용성을 평가하고자 하였다. 대상 및 방법 : $[^{18}F]FHBG$는 triester로부터 8단계를 거쳐 합성하였다. $[^{18}F]FHBG$는 전구체로 N2-monomethoxytrityl-9-[4-(tosyl)-3-monomethoxytritylmethylbutyl]guanine를 사용하고 kyptofix [2.2.2.]를 이용한 친핵성 반응으로 $120^{\circ}C$에서 20분 동안 반응한 후에 1 N HCl로 보호기를 제거함으로써 합성하였다. HSV1-tk 보고 유전자가 이입되어 있는 세포주인 MCA-tk와 이입되지 않은 MCA 세포주를 이용하여 in vitro 상에서의 $[^{18}F]FHBG$의 섭취 및 방출 실험을 실시하였으며 섭취량과 발현량의 상관성 평가를 위해 세포수 백분율에 따른 섭취실험을 실시하였다. In vivo 상에서의 평가를 위하여 피하 종양 형성 동물모델을 이용하여 microPET생체영상을 획득하였다. 결과: 합성된 $[^{18}F]FHBG$를 역상 HPLC를 사용하여, 머무름 시간 16-18분에서 분리하였다. 반감기를 고려한 방사화학적 수율은 20-25%, 방사화학적 순도는 95% 이상이었으며 비방사능은 55.0 $GBq/{\mu}\;mol$ 이상이었다. HSV1-tk 유전자가 이입된 MCA-tk 세포에서는 특이적인 $[^{18}F]FHBG$의 집적이 발생하였으며 대조군인 MCA에서는 거의 집적이 이루어지지 않았다. 또한, 방출 실험에서 방출 후 1시간 경과까지 86% 이상의 $[^{18}F]FHBG$가 세포내에 잔류하였다. MCA-tk 세포주의 비율이 증가함에 따라 $[^{18}F]FHBG$의 섭취량도 직선적 상관관계($R^2=0.995$)에 따라 증가하여 기질의 섭취량이 유전자 발현량을 잘 반영하고 있음이 확인되었다. MicroPET을 이용한 생체영상에서도 MCA와 MCA-tk 에서 확연한 집적의 차이를 보여주었다. 결론: 간암세포주에서 HSV1-tk 유전자의 발현 정도와 지속성 그리고 위치를 확인하기 위한 비침습적 PET 영상을 위한 기질로서 $[^{18}F]FHBG$는 매우 유용할 것으로 기대된다.

• 대한의용생체공학회:의공학회지
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• 제6권2호
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• pp.1-8
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• 1985

The wall shear stress in the vicinity of end-to end anastomoses under steady flow conditions was measured using a flush-mounted hot-film anemometer(FMHFA) probe. The experimental measurements were in good agreement with numerical results except in flow with low Reynolds numbers. The wall shear stress increased proximal to the anastomosis in flow from the Penrose tubing (simulating an artery) to the PTFE: graft. In flow from the PTFE graft to the Penrose tubing, low wall shear stress was observed distal to the anastomosis. Abnormal distributions of wall shear stress in the vicinity of the anastomosis, resulting from the compliance mismatch between the graft and the host artery, might be an important factor of ANFH formation and the graft failure. The present study suggests a correlation between regions of the low wall shear stress and the development of anastomotic neointimal fibrous hyperplasia(ANPH) in end-to-end anastomoses. 30523 T00401030523 ^x Air pressure decay(APD) rate and ultrafiltration rate(UFR) tests were performed on new and saline rinsed dialyzers as well as those roused in patients several times. C-DAK 4000 (Cordis Dow) and CF IS-11 (Baxter Travenol) reused dialyzers obtained from the dialysis clinic were used in the present study. The new dialyzers exhibited a relatively flat APD, whereas saline rinsed and reused dialyzers showed considerable amount of decay. C-DAH dialyzers had a larger APD(11.70$\pm$1.32mmHg/min)compared to CF dialyzers(4.32$\pm$0.55mmHg/min)(p<0.05). However, there was no observable difference in the UFR between the two dialyzers. Neither APD nor UFR showed any significant increase with an increasing number of reuses for up to more than 20reuses. A substantial number of failures observed in APD(larger than 20mmHe/min)on the reused dialyzers(2 out of 40 CP and S out 26 C-DAK) were attributed to the Possible damage on the fibers. The CF 15-11 HFDs which failed APD test did not show changes in the UFR compared to normal dialyzers indicating that APD is a more sensitive test than UFR test to evaluate the integrity of the fibers. 30527 T00401030527 ^x For quantitative measurement of reflected light from a clinical diagnostic strip, a prototype old reflectance photometer was designed. The strip loader and cassette were made to obtain more accurate reflectance parameters. The strip was illuminated at 45˚c through optical fiber and the intensity of reflected light was determined at rectanguLat angle using a photodiode. The kubelka-munk coefficient and reflection optical density were determined ar four different wavelengths(500, 550, 570 and 610nm) for blood glucose strip. For higher concentration than 300mg/41 about glucose, a saturation state of abforbance was observed at 500, 550 and 570nm. The correlation between glucose concentration and parameters was the best at 610nm. 30535 T00401030535 ^x Radiation-induced fibrosarcoma tumors were grown on the flanks of C3H mice. The mice were divided into two groups. One group was injected with Photofrin II, intravenously (2.5mg/kg body weight). The other group received no Photofrin II. Mice from both groups were irradialed for approximately 15 minutes at 100, 300, or 500 mW/cm2 with the argon (488nm/514.5 nm), dye(628nm) and gold vapor (pulsed 628 nm) laser light. A photosensitizer behaved as an added absorber. Under our experimental conditions, the presence of Photolfrin II increased surface temperature by at least 40% and the temperature rise due to 300 mW/cm2 irradiation exceeded values for hyperthermia. Light and temperature distributions with depth were estimated by a computer model. The model demonstrated the influence of wavelength on the thermal process and proved to be a valuable tool to investigate internal temperature rise. 30536 T00401030536 ^x We investigated the structural geometry of thirty-eight Korean femurs. The purpose of this study is to identify major geometrical differences between Korean femurs 3nd others that we believe belong to Caucasians so that we would be able to get insights into the femoral component design that fits Asians including Koreans. We utilized computerized tomography (CT) images of femurs extracted from cadavers. The CT images were transformed into bitmap data by using a film scanner, and then analyzed by using a commercially available software called Image v.1.0 and a Macintosh IIci computer.The resulting data were compared with already published data. The major results show that the geometry of the Korean femurs is significantly different from that of Caucasians: (1) the anteversion angle and the canal flare index are greater by the amount of approximately 8˚ and 0.5, respectively, (2) the shape of the isthmus cross section is more round, and (3) the distance between the teaser trochanter and the proximal border of the isthmus is shelter by about 15 mm. The results suggested that the femoral component suitable for Asians should be different from the currently-used components designed and manufactured mostly by European or American companies. 30537 T00401030537 ^x It is well known that nonlinear propagation characteristics of the wave in the tissue may give very useful information for the medical diagnoisis. In this paper, a new method to detect nonlinear propagation characteristics of the internal vibration in the tissue for the low frequency mechanical vibration by using bispectral analysis is proposed. In the method, low frequency vibration of f0( = 100Hz) is applied on the surface of the object, and the waveform of the internal vibration x (t) is measured from Doppler frequency modulation of silmultaneously transmitted probing ultrasonic waves. Then, the bispectra of the signal x (t) at the frequencies (f0, f0) and (f0, 2f0) are calculated to estimate the nonlinear propagation characteristics as their magnitude ratio, w here since bispectrum is free from the gaussian additive noise we can get the value with high S/N. Basic experimental system is constructed by using 3.0 MHz probing ultrasonic waves and the several experiments are carried out for some phantoms. Results show the superiority of the proposed method to the conventional method using power spectrum and also its usefulness for the tissue characterization. 30541 T00401030541 ^x This paper describes the implementation of a computerized radial pulse diagnosis by aids of a clinical expert. On this base, we composed of the radial pulse diagnosis system in korean traditional medicine. The system composed of a radial pulse wave detection system and a radial pulse diagnosis system. With a detection system, we detected Inyoung and Cheongu radial pulse wave and processed it. Then, we have got the characteristic parameters of radial pulse wave and also quantified that according to the method of Inyoung-Cheongu Comparison Radial Pulse Diagnosis. We defined the jugement standard of radial pulse diagnosis system and then we confirmed the possibility for realization of automatic radial pulse diagnosis in korean traditional medicine. 30545 T00401030545 ^x Microspheres are expected to be applied to biomedical areas such as solid-phase immunoassays, drug delivery systems, immunomagnetic cell separation. To synthesize microspheres for biomedical application, "two stage shot growth method" was developed. The uniformity ratio of synthesized microspheres was always smaller than 1.05. And the surface charge density (or the number of ionizable functional groups) of the microspheres synthesized by "two stage shot growth method" was 6~13 times higher than that of the microspheres synthesized by conventional seeded batch copolymerization. As a previous step for biomedical application, adsorption experiments of bovine albumin on microspheres were carried out under various conditions. The maximum adsorbed amount was obtained in the neighborhood of pH 4.5. Isoelectric point of bovine albumin is pH 5.0, so experimental result shows that it shifted to acid area. The adsorption isotherm was obtained, the plateau region was always reached at 2.Og/L (bulk concentration of bovine albumin).The effect of the kind and the amount of surface functional group was also examined. 30575 T00401030575 ^x A medical image workstation was developed using multimedia technique. The system based on PC-486DX was designed to acquire medical images produced by medical imaging instruments and related audio information, that is, doctors' reporting results. Input information was processed and analyzed, then the results were presented in the form of graph and animation. All the informations of the system were hierarchically related with the image as the apex. Processing and analysis algorithms were implemented so that the diagnostic accuracy could be improved. The diagnosed information can be transferred for patient diagnosis through LAN(local area network). 30592 T00401030592 ^x In the conventional infrared imaging system, complex infrared lens systems are usually used for directing collimated narrow infrared beams into the high speed 2-dimensional optic scanner. In this paper, a simple reflective infrared optic system with a 2-dimensional optic scanner is proposed for the realization of medical infrared thermography system. It has been experimentally proven that the intfrared thermography system composed of the proposed optic system has the temperature resolution of 0.1˚c under the spatial resolution of lmrad, the image matrix size of 256 X 240, and tile imaging time of 4 seconds. 30593 T00401030593 ^x In this paper, MIIS (Medical Image Information System) has been designed and implemented using INGRES RDBMS, which is based on a client/server architecture. The implemented system allows users to register and retrieve patient information, medical images and diagnostic reports. It also provides the function to display these information on workstation windows simultaneously by using the designed menu-driven graphic user interface. The medical image compression/decompression techniques are implemented and integrated into the medical image database system for the efficient data storage and the fast access through the network. 30594 T00401030594 ^x In this paper, computerized BEAM was implemented for the space domain analysis of EEG. Trans-formation from temporal summation to two-dimensional mappings is formed by 4 nearest point inter-polaton method. Methods of representation of BEAM are two. One is dot density method which classify brain electrical potential 9 levels by dot density of gray levels and the other is colour method which classify brain electrical 12 levels by red-green colours. In this BEAM, instantaneous change and average energy distribution over any arbitrary time interval of brain electrical activity could be observed and analyzed easily. In the frequency domain, the distribution of energy spectrum of a special band can easily be distinguished normality and abnormality. 30608 T00401030608 ^x Laboratory information system (LIS) is a key tool to manage laboratory data in clinical pathology. Our department has developed an information system for routine hematology using down-sized computer system. We have used an IBM 486 compatible PC with 16MB main memory, 210 MB hard disk drive, 9 RS-232C port and 24 pin dot printer. The operating system and database management system were SCO UNIX and SCO foxbase, respectively. For program development, we used Xbase language provided by SCO foxbase. The C language was used for interface purpose. To make the system use friendly, pull-down menu was used. The system connected to our hospital information system via application program interface (API), so the information related to patient and request details is automatically transmitted to our computer. Our system interfaced with fwd complete blood count analyzers(Sysmex NE-8000 and Coulter STKS) for unidirectional data tansmission from analyzer to computer. The authors suggests that this system based on down-sized computer could provide a progressive approach to total LIS based on local area network, and the implemented system could serve as a model for other hospital's LIS for routine hematology. 30609 T00401030609 ^x To develop an artificial bone substitute that is gradually degraded and replaced by the regenerated natural bone, the authors designed a composite that is consisted of calcium phosphate and collagen. To use as the structural matrix of the composite, collagen was purified from human umbilical cord. The obtained collagen was treated by pepsin to remove telopeptides, and finally, the immune-free atelocollagen was produced: The cross linked atelocollagen was highly resistant to the collagenase induced collagenolysis. The cross linked collagen demonstrated an improved tensile strength. 30618 T00401030618 ^x This paper is a study on the design of adptive filter for QRS complex detection. We propose a simple adaptive algorithm to increase capability of noise cancelation in QRS complex detection with two stage adaptive filter. At the first stage, background noise is removed and at the next stage, only spectrum of QRS complex components is passed. Two adaptive filters can afford to keep track of the changes of both noise and QRS complex. Each adaptive filter consists of prediction error filter and FIR filter The impulse response of FIR filter uses coefficients of prediction error filter. The detection rates for 105 and 108 of MIT/BIH data base were 99.3% and 97.4% respectively. 30619 T00401030619 ^x To develop an artificial bone substitute that is gradually degraded and replaced by the regenerated natural bone, the authors designed and produced a composite that is consisted of calcium phosphate and collagen. Human umbilical cord origin pepsin treated type I atelocollagen was used as the structural matrix, by which sintered or non-sintered carbonate apatite was encapsulated to form an inorganic-organic composite. With cross linking atelocollagen by UV ray irradiation, the resistance to both compressive and tensile strength was increased. Collagen degradation by the collagenase induced collagenolysis was also decreased. 30620 T00401030620 ^x We have developed a monoleaflet polymer valve as an inexpensive and viable alternative, especially for short-term use in the ventricular assist device or total artificial heart. The frame and leaflet of the polymer valve were made from polyurethane, To evaluate the hemodynamic performance of the polymer valve a comparative study of flow dynamics past a polymer valve and a St. Jude Medical prosthetic valve under physiological pulsatile flow conditions in vitro was made. Comparisons between the valves were made on the transvalvular pressure drop, regurgitation volume and maximum valve opening area. The polymer valve showed smaller regurgitation volume and transvalvular pressure drop compared to the mechanical valve at higher heart rate. The results showed that the functional characteristics of the polymer valve compared favorably with those of the mechanical valve at higher heart rate. 30621 T00401030621 ^x Explosive evaporative removal process of biological tissue by absorption of a CW laser has been simulated by using gelatin and a multimode Nd:YAG laser. Because the point of maximun temperature of laser-irradiated gelatin exists below the surface due to surface cooling, evaporation at the boiling temperature is made explosively from below the surface. The important parameters of this process are the conduction loss to laser power absorption (defined as the conduction-to-laser power parameter, Nk), the convection heat transfer at the surface to conduction loss (defined as Bi), dimensionless extinction coefficient (defined as Br.), and dimensionless irradiation time (defined as Fo). Dependence of Fo on Nk and Bi has been observed by experiment, and the results have been compared with the numerical results obtained by solving a 2-dimensional conduction equation. Fo and explosion depth (from the surface to the point of maximun temperature) are increased when Nk and Bi are increased.To find out the minimum laser power for explosive evaporative removal process, steady state analysis has been also made. The limit of Nk to induce evaporative removal, which is proportional to the inverse of the laser power, has been obtained. 30622 T00401030622 ^x N1 and N2 gross neural action potentials were measured from the round window of the guinea pig cochlea at the onset of the acoustic stimuli. N1-N2 audiograms were made by means of regulating stimulant intensities in order to produce constant N1-N2 potentials as criteria for different input tone pip frequencies. The lowest threshold was measured with an input tone pip I5 dB SPL in intensity and 12 KHz in frequency when the animal was in normal physiological condition. The procedure of experimental measurements is explained in detail. This experimental approach is very useful for the investigation of the Cochlear function. Both noN1inear and active functions of the Cochlea can be monitored by N1-N2 audiograms. 30623 T00401030623 ^x In electrical impedance tomography(EIT), we use boundary current and voltage measurements toprovide the information about the cross-sectional distribution of electrical impedance or resistivity. One of the major problems in EIT has been the inaccessibility of internal voltage or current data in finding the internal impedance values. We propose a new image reconstruction method using internal current density data measured by NMR. We obtained a two-dimensional current density distribution within a phantom by processing the real and imaginary MR images from a 4.77 NMR machine. We implemented a resistivity mage reconstruction algorithm using the finite element method and sensitivity matrix. We presented computer simulation results of the mage reconstruction algorithm and furture direction of the research. 30624 T00401030624 ^x A new method of digital image analysis technique for discrimination of cancer cell was presented in this paper. The object image was the Thyroid eland cells image that was diagnosed as normal and abnormal (two types of abnormal: follicular neoplastic cell, and papillary neoplastic cell), respectively. By using the proposed region segmentation algorithm, the cells were segmented into nucleus. The 16 feature parameters were used to calculate the features of each nucleus. A9 a consequence of using dominant feature parameters method proposed in this paper, discrimination rate of 91.11% was obtained for Thyroid Gland cells. 30625 T00401030625 ^x An electrical stimulator was designed to induce locomotion for paraplegic patients caused by central nervous system injury. Optimal stimulus parameters, which can minimize muscle fatigue and can achieve effective muscle contraction were determined in slow and fast muscles in Sprague-Dawley rats. Stimulus patterns of our stimulator were designed to simulate electromyographic activity monitored during locomotion of normal subjects. Muscle types of the lower extremity were classified according to their mechanical property of contraction, which are slow muscle (msoleus m.) and fast muscle (medial gastrocneminus m., rectus femoris m., vastus lateralis m.). Optimal parameters of electrical stimulation for slow muscles were 20 Hz, 0.2 ms square pulse. For fast muscle, 40 Hz, 0.3 ms square pulse was optimal to produce repeated contraction. Higher stimulus intensity was required when synergistic muscles were stimulated simultaneously than when they were stimulated individually. Electrical stimulation for each muscle was designed to generate bipedal locomotion, so that individual muscles alternate contraction and relaxation to simulate stance and swing phases. Portable electrical stimulator with 16 channels built in microprocessor was constructed and applied to paraplegic patients due to lumbar cord injury. The electrical stimulator restored partially gait function in paraplegic patients. 30626 T00401030626 ^x Two-Dimensional modelling of the Cochlear biomechanics is presented in this paper. The Laplace partial differential equation which represents the fluid mechanics of the Cochlea has been transformed into two-dimensional electrical transmission line. The procedure of this transformation is explained in detail. The comparison between one and two dimensional models is also presented. This electrical modelling of the basilar membrane (BM) is clearly useful for the next approach to the further. Development of active elements which are essential in the producing of the sharp tuning of the BM. This paper shows that two-dimension model is qualitatively better than one-dimensional model both in amplitude and phase responses of the BM displacement. The present model is only for frequency response. However because the model is electrical, the two-dimensional transmission line model can be extended to time response without any difficult. 30627 T00401030627 ^x A method has been proposed for the fully automatic detection of left ventricular endocardial boundary in 2D short axis echocardiogram using geometric model. The procedure has the following three distinct stages. First, the initial center is estimated by the initial center estimation algorithm which is applied to decimated image. Second, the center estimation algorithm is applied to original image and then best-fit elliptic model estimation is processed. Third, best-fit boundary is detected by the cost function which is based on the best-fit elliptic model. The proposed method shows effective result without manual intervention by a human operator. 30628 T00401030628 ^x The intelligent trajectory control method that controls moving direction and average velocity for a prosthetic arm is proposed by pattern recognition and force estimations using EMG signals. Also, we propose the real time trajectory planning method which generates continuous accelleration paths using 3 stage linear filters to minimize the impact to human body induced by arm motions and to reduce the muscle fatigue. We use combination of MLP and fuzzy filter for pattern recognition to estimate the direction of a muscle and Hogan's method for the force estimation. EMG signals are acquired by using a amputation simulator and 2 dimensional joystick motion. The simulation results of proposed prosthetic arm control system using the EMf signals show that the arm is effectively followed the desired trajectory depended on estimated force and direction of muscle movements. 30638 T00401030638 ^x A new neural network architecture for the recognition of patterns from images is proposed, which is partially based on the results of physiological studies. The proposed network is composed of multi-layers and the nerve cells in each layer are connected by spatial filters which approximate receptive fields in optic nerve fields. In the proposed method, patterns recognition for complicated images is carried out using global features as well as local features such as lines and end-points. A new generating method of matched filers representing global features is proposed in this network. 30659 T00401030659 ^x An implementation scheme of the magnetic nerve stimulator using a switching mode power supply is proposed. By using a switching mode power supply rather than a conventional linear power supply for charging high voltage capacitors, the weight and size of the magnetic nerve stimulator can be considerably reduced. Maximum output voltage of the developed magnetic nerve stimulator using the switching mode power supply is 3, 000 volts and switching time is about 100 msec. Experimental results or human nerve stimulations using the developed stimulator are presented. 30768 T00401030768 ^x In this paper, we describe the design methodology and specifications of the developed module-based bedside monitors for patient monitoring. The bedside monitor consists of a main unit and module cases with various parameter modules. The main unit includes a 12.1" TFT color LCD, a main CPU board, and peripherals such as a module controller, Ethernet LAN card, video card, rotate/push button controller, etc. The main unit can connect at maximum three module cases each of which can accommodate up to 7 parameter modules. They include the modules for electrocardiograph, respiration, invasive blood pressure, noninvasive blood pressure, temperature, and SpO2 with Plethysmograph.SpO2 with Plethysmograph.