알코올을 처리한 HepG2 세포에서 참죽나무 잎 추출물의 세포 보호 및 항산화 효과

김현정,조수연,김정봉,김헌웅,최정숙,장환희,Kim, Hyun-Jeong,Cho, Su-Yeon,Kim, Jung-Bong,Kim, Heon-Woong,Choe, Jeong-Sook,Jang, Hwan-Hee 한국식품영양학회 2018 韓國食品營養學會誌 Vol.31 No.4

All the parts of the Cedrela sinensis A. Juss., including the seeds, roots, and leaves, have been known to exert medicinal effects. The C. sinensis and its major compound, quercetin, were previously reported to exhibit the anti-inflammatory and anti-oxidative activities. However, the hepatoprotective effects of the C. sinensis leaves against the alcohol-induced oxidative stress in the HepG2 cells have not been studied. In this study, we investigated the antioxidant activities and analyzed the flavonoid contents of the C. sinensis-leaf extract (CE). The total flavonoid contents of the CE is 1,874.5 mg/100 g dry weight (DW), while the total quercetin 3-O-rhamnoside (quercitrin) contents, which was identified as the major flavonol in the CE, is 1,456.0 mg/100 g DW. In the ethanol-stimulated HepG2 cells, the CE effectively prevented the cytotoxic effect and increased the gene expression of the antioxidant enzymes, such as the heme oxygenase-1 (HO-1) and the glutathion peroxide (GPx). The level of the reactive oxygen species (ROS) production was significantly decreased in the CE-treated HepG2 cells. In conclusion, the C. sinensis extract suppressed the alcohol-induced oxidative stress in the HepG2 cells via the induced GPx and HO-1 gene expressions. It is expected the CE positive effects will likely be attributed to the flavonoids, like the quercetin, within the CE.

유아교사 요구에 기초한 장애유아 통합교육 연수프로그램이 교사효능감과 만족도에 미치는 효과

김현정(Kim Hyun-jeong),홍혜경(Hong Haekyung) 한국열린유아교육학회 2007 열린유아교육연구 Vol.12 No.6

본 연구는 유아교사 요구에 기초한 장애유아 통합교육 연수프로그램이 통합교육 교사효능감과 만족도를 알아보는데 있다. 연구의 대상은 연구자가 개발한 장애유아 통합교육 교사 연수프로그램에 참여한 실험집단 22명과 정부기관에서 위탁 통합교육 일반연수에 참여한 통제집단 교사 22명으로, 현재 유아교육현장에서 장애유아를 담당하고 있는 일반유아교사이다. 본 연구의 도구로는 통합교육 교사효능감을 측정하기 위하여 배재정(2005)이 번역하여 사용한 교사효능감의 도구와 김정주(2005), 조광순과 황인갑(2003), 조운주(2004)가 사용한 연수프로그램에 대한 교사의 만족도를 사용하였다. 자료분석은 실험집단과 통제집단간 통합교육 교사효능감의 차이를 비교하기 위하여 통합교육 교사효능감 사전검사 점수를 공변인으로 하고, 사후검사 점수를 종속변인으로 한 ANCOVA를 실시하였으며, 프로그램 만족도의 두 집단 간 차이를 비교하기 위해 t검증을 하였다. 장애유아 통합교육 유아교사 연수프로그램의 효과를 검증한 결과, 통합교육 교사효능감은 실험집단이 통제집단보다 매우 유의하게 높은 것으로 밝혀졌다. 교사효능감의 두 가지 하위영역인 일반적 교사효능감, 개인적 교사효능감에서 있어서도 실험집단이 통제집단보다 매우 유의하게 높은 것으로 나타났다. 또한 본 연구에 참여한 실험집단 교사들은 통제집단 교사들보다 연수에 대한 만족도에서 점수가 높은 것으로 나타났으며, 이러한 차이는 두 집단 간에 통계적으로 유의한 차이가 나타났다. This study examines the effects of a training program of inclusive education for young children with disabilities based on childcare teachers' demands on the teachers' efficacy and satisfaction. The subjects of this study were ordinary childcare teachers at early childhood education institutions executing inclusive education for ordinary and disabled young children. We applied a training program of inclusive education for young children with disabilities to the experimental group of 22 ordinary childcare teachers, and a training program of inclusive education entrusted by institutions to the control group of 22 teachers. In this study, inclusive education teachers' efficacy was measured with the teacher efficacy scale translated by Bae Jae-jeong (2005) and teachers' satisfaction was measured with the scale of satisfaction with training programs used by Kim Jeong-joo (2005), Cho Gwang-soon and Hwang In-gap (2003) and Cho Woon-joo (2004). In data analysis, the difference in inclusive education teachers' efficacy between the experimental group and the control group was analyzed through ANCOVA with the score of pretest on inclusive education teachers' efficacy as a covariate and the score of posttest as a dependent variable. In addition, the difference in satisfaction with programs between the two groups was examined by t-test. According to the results of testing the effect of the training program of inclusive education for young children with disabilities, the experimental group showed significantly higher teacher efficacy than the control group. In the two sub-areas of teacher efficiency - general teacher efficacy and personal teacher efficacy - the experimental group was significantly higher than the control group. In addition, the teachers in the experimental group showed a higher score of satisfaction than those in the control group, and the difference was statistically significant.

자기주도적 학습능력 촉진을 위한 학업성취도 분석 기반의 수행평가 시스템 구현

김현정,최진식,Kim, Hyun-Jeong,Choi, Jin-Seek 한국정보교육학회 2009 정보교육학회논문지 Vol.13 No.3

The objective of this paper is an implementation of analysing and predicting functions to promote self-directed learning for student's performance assessment system in programming subjects. By adapting Rubric model, the proposed functions inform a student of the assessment criteria and level to be carried out with respects to two-way specifications such as rational ability, problem solving ability and creativity. The proposed system also provides a graphical results of each ability instead of assessment result, for better understanding and analyzing himself/herself based on to the performance assessment and the result. Moreover, the proposed system contains a method to predict future achievement result with moving average technique. Therefore, an academic achievement can be precisely determined by himself/herself to estimate self-directed learning. The teacher can provide different level of educational resources such as supplement learning, problem explains and private instructor etc., in order to maximize efficiency of education.

족관절 해면골의 미세 구조 분석

김현정,안태선,백명현,최문권,원예연,Kim, Hyon-Jeong,An, Tae-Sun,Baek, Myong-Hyun,Choi, Mun-Kwon,Won, Ye-Yeon 대한족부족관절학회 2004 대한족부족관절학회지 Vol.8 No.2

Purpose: This study aimed to investigate and compare the micro-structural profiles of trabecular bone from different facets at the ankle joint. Materials and Methods: In a fresh cadaver ankle, four cored 10 mm of diameter cylindrical specimens of trabecular bone were harvested from the distal tibia, the talar dome, the medial malleolus, and the lateral malleolus. Using a micro-computed tomography, two-dimensional and three-dimensional micro-structural indices of the trabecular bone were analyzed. Results: Each specimen from the tibia, talus, medial malleolus, and the lateral malleolus showed unique micro-structural pattern. Tibia versus talus, the talus was seen a higher bone volume fraction and a wider supporting zone subchondrally whereas the tibia was seen a relatively lower bone volume fraction and a much narrower supporting zone subchondrally. Lateral malleolus versus medial malleolus, the lateral malleolus was seen the thicker but sparse trabeculae pattern whereas the medial malleolus was seen the thinner but more compact trabecular pattern. Conclusion: Each four locations from the different facet at the ankle joint have distinct own micro-structural patterns of the trabecular bone, suggesting different mechanical properties.

Metal Powder에 따른 증기화 증폭 시트의 개발을 통한 열 중량 분석 및 고출력 전자빔의 가공 특성 분석

김현정,정성택,이주형,백승엽,Kim, Hyun-Jeong,Jung, Sung-Taek,Lee, Joo-Hyung,Baek, Seung-Yub 한국금형공학회 2020 한국금형공학회지 Vol.14 No.1

An electron beam was used to mainly utilize for polishing, finishing, welding, a lithography process, etc. Due to the high technical level of difficulty of high-power density electron beam, it is difficult to secure related technologies. In this study, research was carried out to improve the machinability by developing the vaporized amplification sheets to realize the electron beam drilling technology. Their vaporized amplification sheets were analyzed by using the measurement of chemical and composition, which is such as TGA, SEM. We analyzed micro-hole processing using a microscope. Also, the thermal characteristics of vaporized amplification sheets are highly significant for applying to high-power density electron beam technique. So, we finished the vaporized amplification sheets according to the process conditions and analyzed it according to the machining conditions of the electron beam. It was confirmed that the effect on the experimental results differs depending on the influence of the metal powder contained in the developed material.

차잎의 초기 성장 시기 동안 lipoxygenase 활성 및 휘발성 향기성분의 변화

김현정,류성권,노진철,이상준,박승국,Kim, Hyun-Jeong,Ryu, Sung-Kwon,Roh, Jin-Chul,Lee, Sang-Jun,Park, Seung-Kook 한국응용생명화학회 2003 한국농화학회지 Vol.46 No.1

Lipoxygenase는 녹차의 전체적인 품질에 영향을 미치는 "신선하고 풋풋한 풀 향기(green odor)" 향기특성을 가지는 $C_6-alcoho$과 $C_6-aldehyde$ 등 $C_6$화합물을 생성시키는데 관여하는 효소로서 잘 알려져 있다. 본 연구에서는 녹차잎의 초기 성장기간인 4뭘 4에서 15일까지 12일 동안에 매일 채엽한 녹차잎의 lipoxygenase 활성을 측정하고, 이에 따른 $C_6$화합물 및 terpene 등 휘발성 향기성분을 분석하여 수확 날짜에 따른 효소 활성과 녹차잎의 중요한 휘발성 향기성분의 변화를 살펴보았다. 효소활성의 측정은 linoleic acid를 기질로 한 흡광도 측정방법을 사용하였고, 휘발성 향기성분은 Solid Phase MicroExtraction (SPME) 방법으로 휘발성 향기성분을 포집한 후에 GC또는 GC-MS를 이용해 분석하였다. 실험 결과, 초기 녹차 잎 성장기간 동안 lipoxygenase 활성과 $C_6$화합물의 함량은 서로 비례하여 증가 또는 감소하였고, 이러한 변화는 당일의 온도변화와 밀접한 관계가 있는 것으로 나타났다. 즉, 온도가 증가함에 따라서 향기성분의 양도 증가하였으며, 너무 이른 시기에 채엽한 시료는 향기 성분이 매우 적은 것으로 나타났다. 본 연구로부터 "신선한 풀향기"와 "향긋한 꽃향기 (floral)" 등 녹차향 품질에 중요한 영향을 미치는 향 화합물들이 녹차의 초기 채엽기간 중에 어떻게 변화하는지에 대해서 확인 할 수 있었으며, 향기품질이 우수한 녹차를 제조하기 위해서는 생엽 성장 기간동안의 향기성분변화를 이해하는 것이 중요하다는 것을 확인하였다. Lipoxygenase is the enzyme responsible for the formation of $C_6$-alcohols and $C_6$-aldehydes ($C_6$-compounds), which are well blown contributors to various types of 'green odor' In green tea. Changes in lipoxygenase activity and volatile compounds of green tea leaves were monitored daily during early growing season. The enzyme activity was spectrophotometrically measured using linoleic acid as a substrate. The volatile compounds were extracted through Solid Phase Micro-Extraction, and were subjected to GC and GC-MS analyses. Results showed that lipoxygenase activity and levels of $C_6$-compounds concomitantly increased or decreased during the early growing season, probably caused by the fluctuation in the daily temperature; increase in temperature led to the increase in enzyme activities and $C_6$-compound levels, whereas leaves plucked too early had low volatile compound levels. In this study, optimum plucking time of tea leaves for the production of high quality green tea with a wellbalanced aroma was determined.

Analysis of Incomplete Data with Nonignorable Missing Values

김현정,Kim, Hyun-Jeong The Korean Data and Information Science Society 2002 한국데이터정보과학회지 Vol.13 No.2

In the case of "nonignorable missing data", it is necessary to assume a model dealing with the missing on each situations. In this article, for example, we sometimes meet situations where data set are income amounts in a survey of individuals and assume a model as the values are the larger, a missing data probability is the higher. The method is to maximize using the EM(Expectation and Maximization) algorithm based on the (missing data) mechanism that creates missing data of the case of exponential distribution. The method started from any initial values, and converged in a few iterations. We changed the missing data probability and the artificial data size to show the estimated accuracy. Then we discuss the properties of estimates.

영지버섯으로부터 homocysteine methyltransferase 를 암호화 하는 metE 유전자의 클로닝 및 E. coli 에서의 발현

김현정,박동철,이갑득,이별라,이갑랑 ( Hyun Jeong Kim,Dong Chul Park,Kap Duk Lee,Byul La Lee,Kap Rang Lee ) 한국균학회 1993 韓國菌學會誌 Vol.21 No.4

Propofol Patient-Controlled Sedation Using WalkMed (Medex Inc, USA) Infusion Pump in Dental Patients

김현정,박창주,염광원,Kim, Hyun-Jeong,Park, Chang-Joo,Yum, Kwang-Won The Korean Dental Society of Anesthsiology 2001 Journal of Dental Anesthesia and Pain Medicine Vol.1 No.1

연구배경: 일반적으로 자가통증조절기가 자가진정조절을 위해 적합한 것으로 알려져 있다. 그러나 이 장치들은 몇몇 진정제 투여 시 너무 긴 최소 폐쇄간격을 가지고 있다 WalkMed사(Medex inc, USA)의 자가통증조절기는 폐쇄간격을 0으로 설정할 수 있으며 30 ml/h로 추가용량을 투여할 수 있다. 이번 연구에서는 환자 개개인의 요구에 맞추어 환자의 진정을 조절하기 위하여 위장치를 이용한 propofol 자가진정조절기의 가능성를 조사하였다. 방법: Propofol과 전산 프로그램된 WalkMed 주입장치를 이용한 자가진정조절법이 치과치료를 받는 24명의 건강한 환자에게 시행되었다. Propofol 지속 주입량은 2 mg/kg/h로, 추가용량은 5 mg으로 조절되었으며 치소 폐쇄간격은 0으로 설정하였다. Ketoloac 30 mg이 통증 조절을 위하여 진정법 시행 전에 근주되었다. 결과: 진정법 시행 동안 주입된 propofol의 평균량은 3.4 mg/kg/h이었으며 평균 추가용량은 1.6 mg/kg/h이었다. 시간 당 추가용량에는 많은 변이가 있었다(0-32). 모든 환자는 진정법 시행 동안 완전한 각성상태였으며 이러한 진정 법에 만족하였다. 진정 법과 관련된 주요한 합병증은 관찰되지 않았다. 결론: WalkMed사의 자가통증조절기를 이용한 propofol 자가진정조절법이 치과 치료를 받는 환자들에게 유용하게 사용될 수 있다.

평면전극구조를 갖는 바이올로진 기반의 일체형 전기변색소자

김현정,이상래,최진희,나윤채,Kim, Hyun-Jeong,Lee, Sang-Rae,Choi, Jin-Hee,Nah, Yoon-Chae 한국분말야금학회 2020 한국분말재료학회지 (KPMI) Vol.27 No.1

Recently, electrochromic devices (ECDs) have gathered increasing attention owing to their high color contrast and memory effect, which make them highly applicable to smart windows, auto-dimming mirrors, sensors, etc. Traditional ECDs have a sandwich structure that contains an electrochromic layer between two ITO substrates. These sandwich-type devices are usually fabricated through the lamination of two electrodes and followed by the injection of a liquid electrolyte in the inner space. However, this process is sometimes complex and time consuming. In this study, we fabricated ECDs with a lateral electrode structure that uses only an ITO substrate and an all-in-one electrochromic gel, which is a mixture of electrolyte and electrochromic material. Furthermore, we investigated the EC properties of the lateral-type device by comparing it with a sandwich-type device. The lateral-type ECD shows strong blue absorption as the applied voltage increases and has a competitive coloration efficiency compared to the sandwich-type device.