흰쥐 C6 신경교종 세포에서 Venlafaxine 그리고 Dexamethasone 처리가 열충격 단백질 70의 발현에 미치는 영향

유재학,이준석,양병환,최미란,채영규,김석현,노성원,오동열,최인근,Yu, Jae-Hak,Lee, Jun-Seok,Yang, Byung-Hwan,Choi, Mi-Ran,Chai, Young-Gyu,Kim, Seok-Hyeon,Roh, Sung-Won,Oh, Dong-Yul,Choi, Ihn-Geun 대한생물정신의학회 2005 생물정신의학 Vol.12 No.2

Object:The intracellular action of the antidepressant, venlafaxine, was studied in C6-gliomas using heat shock protein 70(HSP70) immunocytochemistry and HSP70 Western blots because HSP70 is associated with stress and depression. Methods:To examine how the glucocorticoid affects the expression of HSP70 in nerve cells, the rat C6 glioma cell was treated with dexamethasone for 6 hours. In addition, venlafaxine was administered to the experimental groups of C6 glioma cells for 1, 6, 24, and 72 hours each, after which the expression of HSP70 was investigated. Finally, venlafaxine and dexamethasone were simultaneously administered to the experimental groups for 1, 6, 24, and 72 hours, followed by an investigation of the expression of HSP70. Results:The short term(1 hour) venlafaxine treatment significantly increased the level of HSP70 expression. The short term treatment of venlafaxine with dexamethasone also increased the level of HSP70 expression but this reduction was not statistically significant. The long term(72 hours) venlafaxine with dexamethasone treatment significantly reduced the level of HSP70 expression. The long term treatment of venlafaxine also reduced the level of HSP70 expression but this reduction was not statistically significant. Dexamethasone(10uM, 6hours) did not affect the level of HSP70 expression compared with controls. Conclusion:Venlafaxine increases the expression of HSP70 at short term treatment, but prolonged treatment with dexamethasone suppresses the expression of HSP70.

SVM을 이용한 SNMP MIB에서의 트래픽 폭주 공격 탐지

유재학,박준상,이한성,김명섭,박대희,Yu, Jae-Hak,Park, Jun-Sang,Lee, Han-Sung,Kim, Myung-Sup,Park, Dai-Hee 한국정보처리학회 2008 정보처리학회논문지 C : 정보통신,정보보안 Vol.15 No.5

DoS/DDoS로 대표되는 트래픽 폭주 공격은 대상 시스템뿐만 아니라 네트워크 대역폭 및 프로세서 처리능력, 시스템 자원 등을 고갈시킴으로써 네트워크에 심각한 장애를 유발하기 때문에, 신속한 트래픽 폭주 공격의 탐지는 안정적인 서비스의 제공 및 시스템의 운영에 필수요건이다. 전통적인 패킷 수집을 통한 DoS/DDoS의 탐지방법은 공격에 대한 상세한 분석은 가능하나 설치의 확장성 부족, 고가의 고성능 분석시스템의 요구, 신속한 탐지를 보장하지 못하는 문제점을 갖고 있다. 본 논문에서는 MIB 정보 갱신 시점 단위로 수집된 SNMP MIB 객체 정보를 바탕으로 Support Vector Data Description(SVDD)을 이용하여 보다 빠르고 정확한 침입탐지와 쉬운 확장성, 저비용탐지 및 정확한 공격유형별 분류를 가능케 하는 새로운 시스템을 설계 및 구현하였다. 실험을 통하여 만족스러운 침입 탐지율과 안전한 False Negative Rate(FNR), 공격유형별 분류율 수치 등을 확인함으로써 제안된 시스템의 성능을 검증하였다. Recently, as network flooding attacks such as DoS/DDoS and Internet Worm have posed devastating threats to network services, rapid detection and proper response mechanisms are the major concern for secure and reliable network services. However, most of the current Intrusion Detection Systems(IDSs) focus on detail analysis of packet data, which results in late detection and a high system burden to cope with high-speed network environment. In this paper we propose a lightweight and fast detection mechanism for traffic flooding attacks. Firstly, we use SNMP MIB statistical data gathered from SNMP agents, instead of raw packet data from network links. Secondly, we use a machine learning approach based on a Support Vector Machine(SVM) for attack classification. Using MIB and SVM, we achieved fast detection with high accuracy, the minimization of the system burden, and extendibility for system deployment. The proposed mechanism is constructed in a hierarchical structure, which first distinguishes attack traffic from normal traffic and then determines the type of attacks in detail. Using MIB data sets collected from real experiments involving a DDoS attack, we validate the possibility of our approaches. It is shown that network attacks are detected with high efficiency, and classified with low false alarms.

함정 전투체계 네트워크의 실시간성 검증툴의 설계 및 구현

신희재(Hee-Jae Shin),권영준(Young-June Kwon),이재호(Jae-Ho Lee),유재학(Jae-Hak Yu),이재민(Jae-Min Lee),김동성(Dong-Seong Kim) 한국통신학회 2024 한국통신학회 학술대회논문집 Vol.2024 No.1

비침습적 측정방법을 이용한 수종 용제가 자극 피부염에 미치는 영향

유재학(Jae Hak Yoo),은희철(Hee Chul Eun),서대헌(Dae Hun Suh),유일재(Il Je Yu) 대한피부과학회 1994 대한피부과학회지 Vol.32 No.6

Background : Solvents play an immense role in the industria sector. Irritant dermatitis which is more common than allergic contact dermatitis can be caused by solvents, Objective : Our purpose was to compare the skin irritancy of several solvents using human and guinea pig skin models. Methods : The skin responses to short contact with etharol, acetone, dimethylsulfoxide (DMSO) and xylene were measured by visual scoring of erythm, transepidermal water loss and laser doppler flowmetry. Results : The results are summarized as follows . 1. Guinea pig and human skin responses to normal saline, ethanol, and acetone were nearly negligible. 2. Guinea pig skin responses to 99.9% DMSO under occlusion for 0.5 min were assessed by visual scoring system, TEWL, and LDF. They are measured 3+0.(0,1+21.70, 45+12.70 at 5 min after removal of 99.9% DMSQ, and 0.83+0.41, 10.5+3.83, 36+4.0, to 120 min after removal. 3. Guinea pig skin responses to 97% xylene under occlusion for 5 nin were assessed by visual scoring system, TEWL and LDF. They are measured 3+0.00, 1. 5.82, 77+11.7 at 5 min after removal of 97% xylene, and 1.83+0.75, 5.5+3.21, 39.17+11.53 at l2 min after removal. 4. Human skin responses to 75% DMSO under occlusion for 1 min were assessed by visual scoring system, TEWL and LDF. They are measured 2,5+0.5, 63+25.8, 51+13.7 at 5 min after removal of 75% DMSO, and 0.17+0.41, 14.67+15.87, 21.17-8. 1 at 120 min after removal. 5. Human skin responses to 97% xylene under occlusion for 12 min were assessed by visual scoring system, TEWL and LDF. They are measured 2.7+0.52+4.22, 76+14.30 at 5 min after removal of 97% xylene, and 0+0, 2.5+0.55, 3.17+0.98, 120 emOVBI. Concbsion : Short contact vrith DMSO and xylene cause visib erythema and an increase in TEWL and cutaneous blood flow. The reaction patterns in hurr an and guinea pig skin models were similar. (Kor J Dermatol 1994: 32(6): 1026-1034)

인체 각질형성세포 배양모델을 이용한 수종 용제의 독성도 측정에 관한 연구

유재학 ( Jae Hak Yoo ),은희철 ( Hee Chul Eun ),정진호 ( Jin Ho Chung ),유일재 ( Il Je Yu ) 대한피부과학회 1996 대한피부과학회지 Vol.34 No.1

Background: As in vivo models such as animal and human tests have many potential problems the keratinocyte culture model has previously been used as an in vitro model for testing skin irritancy for common skin irritants. Objective : To determine the skin irritant potency of several solvents, we employed cultured human keratinocytes as an in vitro model. Methods : To evaluate the cytotoxicity of solvents, the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide(MTT) test, lactic dehydrogenase(LDH) release test, and tritiated thymidine incorporation test were used. Results : Dose dependent decrease of cell viability and DNA synthesis, and dose dependent increase in leakage of LDH liberation were observed in normal cultured human keratinocytes after exposure to several solvents. The cytotoxicity potency of several solvents measured by each method were slightly different. Conclusion : These observations suggest that the cultured human keratinocyte model would be useful in evaluating the cytotoxicity of solvents. (Kor J Dermatol 1996;34(1): 58~63)

함정 네트워크 성능 시험을 위한 트래픽 시험도구 설계 및 구현

김재우(Jae-Woo Kim),류주연(Ju-yeon Ryu),유재학(Jae-hak Yu),김동성(Dong-Seong Kim) 한국통신학회 2023 한국통신학회 학술대회논문집 Vol.2023 No.6

수면과 알코올

박두흠,유재학,유승호,Park, Doo-Heum,Yu, Jae-Hak,Ryu, Seung-Ho 대한수면의학회 2006 수면·정신생리 Vol.13 No.1

Alcohol has extensive effects on sleep and daytime sleepiness. Alcohol has a sleep inducing effect and the effect of increased non-REM sleep and suppressed REM sleep during the first half portion of night sleep, but alcohol induces the effect of decreased non-REM sleep and increased light sleep and frequent awakenings and REM rebound during the second half portion of night sleep. Alcohol provokes chronobiological change such as the changes of amplitude or the phase shifts of hormones or core body temperature. The sleep disruption resulting from alcohol drinking may lead to daytime fatigue and sleepiness. The elderly are at particular in the increased risk of alcohol-related sleep disorders because they achieve higher levels of alcohol in the blood and brain than do younger adults after consuming an equivalent dose. Bedtime alcohol consumption among older adults may lead to unsteadiness if walking is attempted during the night, with increased risk of falls and injuries. Continued alcohol use for sleep induction often induces aggravation of insomnia, alcoholism or sleep related breathing disorders such as obstructive sleep apnea. Alcohol should not be used as substitution of sleep pill because of the dependence and tolerance for sleep inducing effect, and the sleep disruption produced by alcohol withdrawal.

일차성 불면증에서 심박동률변이도와 수면구조 간의 상관관계

이상진,박두흠,유재학,유승호,하지현,송만규,Lee, Sang-Jin,Park, Doo-Heum,Yu, Jae-Hak,Ryu, Seung-Ho,Ha, Ji-Hyeon,Song, Man-Kyoo 대한수면의학회 2010 수면·정신생리 Vol.17 No.1

목 적: 일차성 불면증(primary insomnia)은 자율신경계에도 영향을 주는 것으로 알려져 있는데 심박동률변이도 (heart rate variability: HRV)를 이용하여 일차성 불면증에서 심박동률변이도 지수와 수면구조(sleep structure) 관련 변인 간의 연관성을 분석하여 일차성 불면증의 야간수면 동안 자율신경계 변화의 특징을 연구하고자 하였다. 방 법: 일차성 불면증 33명(평균연령: 36.2${pm}$14.2세, 남:여=15:18)을 대상으로 1일밤 야간수면다원검사(nocturnal polysomnography:NPSG)를 시행하여 HRV 지수 중 저주파수/고주파수 비(high frequency/low frequency ratio:LF/HF ratio)와 NPSG에서 산출된 수면구조 관련변인 간의 상관관계를 분석하였다. 결 과: 연령과 성별을 통제한 상태에서 LF/HF ratio와 서파수면(slow wave sleep)의 시간과 분율, 2단계수면시간 (stage 2 sleep)과 분율이 각각 음의 상관관계($r_p$=-0.37, p=0.04, $r_p$=-0.4, p=0.02; $r_p$=-0.42, p=0.02, $r_p$=-0.43, p=-0.01)를 가지는데 비해 각성지수(arousal index)와는 양의 상관관계($r_p$=0.65, p<0.001)를 보였다. 결 론: 일차성 불면증에서 수면구조 변화에 따라 자율신경계가 반응하고 있으며, 특히 비렘수면(Non-REM sleep)의 구성요소인 서파수면과 2단계수면의 감소와 각성 횟수의 증가가 교감신경 항진을 유발하여 불면증의 전형적인 수면 구조 변화가 심혈관계에 부정적 영향을 줄 수 있다는 것을 보여준다. Objectives: It is well established that primary insomnia affects the activity of autonomic nervous system. We tried to know how the activity of autonomic nervous system during night sleep changes by analyzing correlation between heart rate variability (HRV) index and the variables related with sleep structure in primary insomnia. Methods: Thirty three subjects (mean age: $36.2{\pm}14.2$ years, male:female=15:18) who were diagnosed with primary insomnia were selected for the study. Nocturnal polysomnography (NPSG) was carried out on each subject and correlation was analyzed between high frequency/low frequency ratio (LF/HF ratio), one of HRV indices and the variables related with sleep structure which were calculated from NPSG. Results: When age and sex were controlled, LF/HF ratio showed negative correlations with slow wave sleep and stage 2 sleep, respectively ($r_p$=-0.43, p=0.01; $r_p$=-0.37, p=0.04). On the other hands LF/HF ratio showed a positive correlation with arousal index ($r_p$=0.65, p<0.001). The activity of autonomic nervous system responded differentially depending on the change of sleep structure in primary insomnia. Especially the increase of arousal index and the decrease of slow wave sleep and stage 2 sleep which are the components of non-REM sleep provoked hyperactivity of sympathetic nervous system. Conclusion: This study suggests that the typical change of sleep structure in primary insomnia can negatively impact on cardiovascular system.

시각혐오자극으로 유발된 대뇌 피질 활성도 변화

정욱,박두흠,유재학,유승호,하지현,신병학,Jung, Wook,Park, Doo-Heum,Yu, Jae-Hak,Ryu, Seung-Ho,Ha, Ji-Hyeon,Shin, Byoung-Hak 대한수면의학회 2013 수면·정신생리 Vol.20 No.2

목 적 : 혐오 자극에 대한 뇌의 기능적 영상 연구에 있어서 기능적 자기공명영상, 양전자방출단층촬영 등의 연구는 많이 진행되어 있으나 저해상 전자기 단층촬영(low resolution brain electromagnetic tomography) 분석을 이용한 연구는 거의 없다. 본 연구의 목적은 피험자들에게 시각적 혐오자극을 준 후 나타나는 대뇌 피질의 활성변화를 저해상 전자기 단층촬영을 이용하여 파악하고자 하는 것이다. 방 법 : 총 45명($27.1{\pm}2.6$세)의 건강한 젊은 성인남녀가 연구에 참여하였다. 국제정서사진체계를 사용하여 중립자극에서 4장, 신체훼손과 관련된 혐오자극에서 4장의 사진을 뽑아 피험자들에게 각 30초간 보여주면서 뇌파를 측정하였다. 저해상 전자기 단층촬영분석을 시행하여 중립자극에 대비해 혐오자극에서의 변화된 전류밀도를 비교 분석하였다. 결 과 : 혐오시각 자극을 받는 동안 피험자 모두 불쾌감, 놀람, 스트레스를 받았다고 보고하였다. 저해상 전자기 단층촬영 분석상 세타파에서 좌측 전두엽의 위이마이랑(BA10)과 중간이마이랑(BA10, 11) 영역에서 유의미한 전류밀도의 감소를 보이는 복셀 클러스터가 관찰되었다. 이 복셀 클러스터는 총 11개의 복셀로 구성되어 있으며 유의미한 전류밀도(p<0.05)의 감소를 나타내는 t값의 임계값은 -1.984이었다. 남녀 간의 혐오 반응 정도에 유의미한 차이는 없었다. 결 론 : 이 연구의 결과인 시각 혐오자극에 의한 배외측 전전두엽의 활성은 혐오 정서의 조절과 관여되어 있을 것으로 생각된다. Objectives: There are a lot of studies that analyze the interaction between the emotion of disgust and the functional brain images using fMRI and PET. But studies using sLORETA (standardized low resolution brain electromagnetic tomography) almost do not exist. The aim of this research is to explore the relationship of the emotion of disgust and the cortical activation using sLORETA analysis. Methods: Forty five healthy young adults ($27.1{\pm}2.6$ years) participated in the study. While they were watching 4 neutral images and 4 disgusting images associated with mutilation selected from the international affective picture system (IAPS), participants' EEGs were taken for 30 seconds per one picture. Through these obtained EEG data, sLORETA analysis was performed to compare EEGs associated with neutral and negative images. Results: During looking for visual disgusting stimulus, all participants reported unpleasantness, arousal and stress. In sLORETA analysis, the decrease of current density in theta wave was shown at left frontal superior gyrus (BA10) and middle gyrus (BA10, 11). This voxel cluster consists of a total of 11 voxels and the threshold of t value indicating statistically significant decreases in the current density (p<0.05) was -1.984. There were no differences between male and female in the degree of being disgusted by the stimuli. Conclusion: This finding may suggest that the activation of dorsolateral prefrontal cortex might be associated with regulating disgust emotion.

전기경련충격시 경쟁적 역전사 중합효소연쇄반응(CRT-PCR)을 이용한 흰쥐 뇌 c-fos 유전자의 발현 양식 분석

양병환,이제욱,박응철,유재학,조광원,양보기,채영규,Yang, Byung-Hwan,Lee, Jei-Wook,Park, Eung-Chul,Yu, Jae-Hak,Cho, Goang-Won,Yang, Bo-Gee,Chai, Young-Gyu 대한생물정신의학회 1996 생물정신의학 Vol.3 No.2

To clarify the mechanism of action of electroconvulsive shack(ECS) in respect to molecular biology, and to detect the quantitative amount of change of c-fos gene expression after ECS in the rat's brain, the authors obtained brain specimens from the striatum, cerebral cortex, hippocampus, and cerebellum. Each brain was removed within 30min. after ECS(130V, 0.5sec) and ECS-sham. Then we performed RT-PCR. The results are 1) ECS was found to affect the expression of immediate early genes. 2) the cerebral cortex and hippocampus was more influenced by ECS thon in the cerebellum and striatum. From these results, we can suggest that ECS is related to the mechanism of cognition, mood, memory which is correlated to cerebral cortex and hippocampus.