Association Between Prolonged Closure Time on the Platelet Function Analyzer-200 and Risk of Perioperative Blood Transfusion

전기범,이지원,이은엽,이지수,김미영,김한성,강희정,이영경 대한진단검사의학회 2019 Annals of Laboratory Medicine Vol.39 No.3

온실 내 백다다기 오이의 생육단계에 따른 흡광계수 변화 모델 개발

전기범,신종화 (사) 한국생물환경조절학회 2023 생물환경조절학회지 Vol.32 No.1

Understanding the light environment in greenhouse cultivation and the light utilization characteristics of crops is important in the study of photosynthesis and transpiration. Also, as the plant grows, the form of light utilization changes. Therefore, this study aims to develop a light extinction coefficient model reflecting the plant growth. To measure the extinction coefficient, five pyranometers were installed vertically according to the height of the plant, and the light intensity by height was collected every second during the entire growing season. According to each growth stage in the early, middle, and late stages, the difference between the top and bottom light intensity tended to increase to 69%, 72%, and 81%. When leaf area index and plant height increased, the extinction coefficient decreased, and it showed an exponential decay relationship. Three-dimensional model reflecting the two growth indexes, the paraboloid had the lowest RMSE of 1.340 and the highest regression constant of 0.968. Through this study, it was possible to predict the more precise light extinction coefficient during the growing period of plants. Furthermore, it is judged that this can be utilized for predicting and analyzing photosynthesis and transpiration according to the plant height. 시설 내 작물이 이용하는 수광특성의 이해와 지속적으로 변화하는 광환경의 추적은 광합성과 증산반응 연구에서 중요하다. 또한 재배기간 동안 작물이 생장함에 따라 광이용 형태가 지속적으로 변화한다. 따라서 본 연구에서는 작물의 생육을 반영한 흡광계수 추정 모델을 개발하였다. 흡광계수의 측정을 위하여 작물의 높이에 따라 수직으로 일사량계를 5개 설치하였으며, 작물의 전 생육기간(1-85DAT) 동안 1초 단위로 측정을 하였다. 초기, 중기, 후기 각각의 생육단계에 따라 최상단 광량과 최하단의 광량의 차이가 69%, 72%, 81%로 증가하는 경향을 보였다. LAI와 초장이 증가함에 따라 흡광계수는 감소하였으며, 지수적 감소 관계를 보였다. 두 생육지표를 모두 반영한 3차원 모델에서는 Paraboloid 식이 평균 제곱근 오차(RMSE)가 1.340으로 가장 낮았고, 결정계수(R2)는 0.968 로 가장 높았다. 본 연구를 통하여 작물 재배기간 동안 보다 정확한 흡광계수를 예측할 수 있게 되었고, 이는 작물의 높이에 따른 광합성 및 증산량 예측과 분석 연구에 활용될 수 있을 것으로 판단된다.

Protective effect of fermented aloe extract on glutamate-induced cytotoxicity in HT22 cells

전기범,이성훈,권용성,백진홍,이현,마충제 한국통합생물학회 2022 Animal cells and systems Vol.26 No.6

Excessive glutamate can cause oxidative stress in neuronal cells and this can significantly contribute to the etiology of neurodegenerative disease. The present study mainly aims to investigate that aloe extract (AE) and fermented aloe extract (FAE) could protect against glutamate-induced cytotoxicity by modulating oxidative stress. In this study, both AE and FAE showed potent neuroprotective activity by inhibiting ROS and Ca2+ concentration, increasing mitochondria membrane potential, and activating glutathione-related enzymes against glutamate-insulted neurotoxicity in HT22 cells. In addition, the neuroprotective activity of FAE was more potent than that of AE. HPLC analysis reveals that the chemical composition of FAE is different from that of AE. Especially, the contents of aloin A, aloin B and aloenin were higher in FAE than in AE. In conclusion, this study indicates that both AE and FAE may have effective neuroprotective activity in glutamate-insulted pathological conditions such as Alzheimer’s disease by managing oxidative stress.

Comparison of Three Methods with CHROMagar for Surveillance Culture of Carbapenem-Resistant Acinetobacter baumannii

전기범,이승순,김현수,김재석,이영경,송원근,김한성 대한임상미생물학회 2020 Annals of clinical microbiology Vol.23 No.2

Background: Carbapenem-resistant Acinetobacter baumannii (CRAB) has emerged as an important nosocomial pathogen.The purpose of this study was to determine the effective methods for performing surveillance cultures of CRAB. Methods: Nasal and rectal swabs were obtained concurrently from hospitalized intensive care unit patients colonized with CRAB. All the samples were inoculated in CHROMagar Acinetobacter medium with CR102 (CHROMagar), MacConkey agar medium supplemented with 5 μg/mL imipenem (MCA-IPM), and triptic soy broth medium supplemented with 5 μg/ mL imipenem (TSB-IPM). CRAB detection rates for each sample were compared. Results: The CRAB detection rate in either one of the nasal or rectal swabs from the 37 patients tested were 89.2% (33/37) with the use of CHROMagar, 78.4% (29/37) with the use of MCA-IMP, and 86.5% (32/37) with the use of TSB-IMP. Conclusion: We determined that concurrent use of both nasal and rectal swabs and CHROMagar could be an effective method for CRAB surveillance cultures.

단백질 고생산 야생형 효모 균주 선별 및 무작위 돌연변이를 통한 단백질 함량 증대

전기범,이영오,주범진,진영욱,김선기 한국산업식품공학회 2023 산업 식품공학 Vol.27 No.3

Protein can be provided by cultivating various microbes, which contain more than 30% protein content by cell dry weight. This study compared intracellular protein concentrations of various wild-type yeasts from different sources to select the best yeast strain with high protein concentration. Among them, Saccharomyces cerevisiae KCCM 34709, used for molasses fermentation, exhibited 4.1-fold higher protein concentration than a laboratory yeast strain, S. cerevisiae D452-2. In this study, an approach consisting of random mutagenesis coupled with the Bradford protein assay-based screening method was applied to enhance the S. cerevisiae KCCM 34709 protein content. Among 1,000 mutants, the #180 mutant strain produced 5,041±519 mg/L total amino acid in 48 h, which was 31% higher than the parental S. cerevisiae KCCM 34709 strain. These results demonstrate that the #180 mutant strain can be an attractive cell factory for animal-free protein production.

Sol-Gel법에 의한 PbZrO$_3$박막 결정의 제작

전기범,김원보,배세환 한국결정성장학회 2000 韓國結晶成長學會誌 Vol.10 No.3

$PbZrO_3$precursor was prepared for the spin coating on the Pt/Ti/$SiO_2$/Si substrate. Two different heat treatment methods were used and the differencies were studied. One of the method is that the films were inserted into the furnace for 30 minutes and the other is that the films were annealed by rapid thermal annealing (RTA) for 1 minute at the same temperatures. We also examined the tendency of crystallization by annealing at the fixed temperature, $700^{\circ}C$ as a function of time, namely during 1, 10, 20, and 30 minitues, respectively. The optimum conditions for the crystallization of these films were at $550^{\circ}C$ during 30 min. and at $700^{\circ}C$ during 10 min. in muffle furnace and at $650^{\circ}C$ during 1 min in RTA furnace. The best condition for making good quality grains needs 30 min. at $700^{\circ}C$. $PbZrO_3$의 전구체 용액을 준비하여 spin coating법으로 Pt/Ti/$SiO_2$/Si 기판 위에 박막을 입힌 후 두가지 방법으로 열처리하여 $PbZrO_3$박막 결정의 형성을 조사하였다. 즉, 하나는 $500^{\circ}C$, $550^{\circ}C$, $600^{\circ}C$, $650^{\circ}C$ 및 $700^{\circ}C$로 가열된 전기로 속에 직접 삽입하여 결정화시켰으며, 다른 한가지 방법은 동일한 온도조건하에서 급속가열방식(RTA)으로 열처리하여 박막을 결정화시켰다. 또 전기로에 삽입하여 $700^{\circ}C$에서 1분, 10분, 20분, 30분 동안 열처리하여 시간의 변화에 따른 결정의 형성과정도 살펴보았다. PZ 박막을 전기로에 직접 삽입한 경우 $600^{\circ}C$에서 30분간 그리고 RTA의 경우 $650^{\circ}C$에서 1분간 열처리 하였을 경우 결정이 형성되었고, $700^{\circ}C$의 전기로에 삽입한 경우에는 10분 이상의 시간이 요구되었다. 그러나 양호한 결정 grain의 형성을 위해서는 $700^{\circ}C$에서 30분간 열처리하는 것이 4가지 열처리 시간 중 가장 좋은 것으로 나타났다.

진공인터럽터의 내전압 성능 향상을 위한 전류컨디셔닝 기법 연구

차영광,이일회,전기범,장지훈,주홍진 한국전기전자재료학회 2022 전기전자재료학회논문지 Vol.35 No.5

As a process to improve the insulation performance of VIs (Vacuum Interrupters), AC voltage conditioning is generally adopted by many manufacturers. Although the insulation performance is enhanced easily with AC Voltageconditioning, it has limitations when high recovery voltage is required due to high voltage rate or capacitive current switching. In particular, impurities such as oxides segregated on the electrode surface can be removed not by the energy level of the voltage conditioning but by the higher energy level achieved by the current conditioning process In this article, the current conditioning was carried out in various conditions and its validity was examined. The current conditioning was processed by changing the amplitude of applied current, arc time, the number of tests, and frequency. The insulation performance and the status of contact surface were checked as well. We concluded that as the applied charge quantity and the conditioning coverage area increase, the conditioning effect is much higher.

지식 기반 추천 시스템을 이용한 식물 추천 시스템

전기범 ( Kibeom Jeon ),이유진 ( Yujin Lee ),안민하 ( Minha Ahn ),김용규 ( Yonggyu Kim ),김영종 ( Youngjong Kim ) 한국정보처리학회 2022 한국정보처리학회 학술대회논문집 Vol.29 No.1

홈가드닝' 시장의 성장이 가속화되면서 식물에 관심을 가지는 사람들이 많아지고 있으나, 초보자의 경우 식물 육성에 있어 어려움이 존재한다. 본 논문에서는 이러한 한계를 극복하기 위한 방안으로 일조량, 계절, 크기 등 세분화된 조건을 바탕으로 하는 지식 기반 추천 시스템을 적용한 식물 추천시스템을 제안하고 있다. 해당 시스템을 통해 사용자의 환경에 맞는 식물을 추천하여 육성 및 관리를 돕고자 한다.

최대 전압 12 kV, 커패시턴스 50~500 pF 가변 진공커패시터 개발

차영광 ( Youngkwang Cha ),이일회 ( Ilhoi Lee ),전기범 ( Kibeom Jeon ),장지훈 ( Jihoon Jang ),주흥진 ( Heungjin Ju ),최승길 ( Seungkil Choi ) 한국전기전자재료학회 2022 전기전자재료학회논문지 Vol.35 No.3

A variable vacuum capacitor (VVC), which is a variable element, is used to match impedance in plasma that changes with various impedance values, and its use is expanding with the rapid growth of the semiconductor business. Since VVCs have to secure insulation performance and vary capacitance within a compact size, electrode design and manufacturing are very important; thus, various technologies such as part design and manufacturing technology and vacuum brazing technology are required. In this study, based on the model of an advanced foreign company that is widely used for impedance matching in the manufacture of semiconductors and displays, a VVC that can realize the same performance was developed. The electrode part was designed, the consistency was confirmed through analysis, and the precision of capacitance was improved by designing a cup-type electrode to secure the concentricity of the electrode. As a result of the evaluation, all requirements was satisfied. We believe that self-development will be possible if satisfactory responses are received through evaluation by VVC consumers in the future.

진공인터럽터용 컵타입 종자계 전극의 접점 슬릿 변화에 따른 자계 최적화 연구

차영광(Young-Kwang, Cha),주흥진(Heong-Jin, Ju),전기범(Ki-Beom, Jeon),윤덕환(Duck-Hwan, Yoon),구치욱(Chi-Wuk, Gu),신태용(Tea-Yong, Sin) 대한전기학회 2017 대한전기학회 학술대회 논문집 Vol.2017 No.10