Anti-Oxidant Activities of Acanthopanax senticosus Stems and Their Lignan Components

이상현,Dongwook Son,Jiyoung Ryu,이연실,정상훈,Jungil Kang,Sang Yun Lee,김현수,Kuk Hyun Shin 대한약학회 2004 Archives of Pharmacal Research Vol.27 No.1

The antioxidant activities of Acanthopanax senticosus stems were evaluated in CCl4-intoxicated rats. The n-butanol fraction from the water extract of the stems, when pretreated orally at 200 mg/kg/day for 7 consecutive days in rats, was demonstrated to exhibit significant increases in antioxidant enzyme activities such as hepatic cytosolic superoxide dismutase, catalase and glutathione peroxidase by 30.31, 19.82 and 155%, respectively. The n-butanol fraction whereas showed a significant inhibition of serum GPT activity (65.79% inhibition) elevated with hepatic damage induced by CCl4-intoxication. Eleutheroside B, a lignan component, isolated from the n-butanol fraction was found to cause a moderate free radical scavenging effect on DPPH, its scavenging potency as indicated in IC50 value, being 58.5 mM. These results suggested that the stems of A. senticosus possess not only antioxidant but also hepatoprotective activities.

인진호탕(茵蔯蒿湯)과 오수목과탕(吳茱木瓜湯)의 항산화(抗酸化) 및 간세포(肝細胞) 보호효과(保護效果)

이상현,김영복,Lee, Sang-Hyun,Kim, Young-Bok 대한한의학방제학회 2008 大韓韓醫學方劑學會誌 Vol.16 No.1

Korean traditional medicine has been used for the treatment of the various diseases based on both oriental medicinal theory and clinical trials. Thus, the prescriptions of Korean traditional medicine would be useful for the development of new therapeutics. This research focuses on the fundamental study in Korean traditional prescriptions for the development of new hepatoprotective agents. We found two prescriptions. Injinho-Tang and Osumogwa-Tang, showed the significant DPPH free radical scavenging and hepatoprotective effect, respectively. It is well-known that free radical scavenging effect is related to the prevention of various pathological events including liver injury. This paper deals with hepatoprotective effects on tacrine-induced cytotoxicity in Hep G2 cells, free radicals scavenging on both DPPH and superoxide of above two prescriptions. Hot water extract of Injinho-Tang did not show the significant hepatoprotective effect on tacrine-induced cytotoxicity in Hep G2 cells, however, it shows the significant scavenging effects for both DPPH and superoxide radicals. On the other hand, all of the hot water extracts of constituent herbal drugs in Injinho-Tang exhibited the promising protective effect on tacrine-induced cytotoxicity in Hep G2 cells. Of these, water extract of Rhei Rhizoma showed the most prominent effect on tacrine-induced cytotoxicity in Hep G2 cells. Bioassay-guided fractionation of Rhei Rhizoma extract has furnished four compounds, and their chemical structures have been identified by comparison of their spectral data with those of literature as chrysophanol (1), emodin (2), 3,5-dihydroxy-4'- methoxystilbene (3), and rhapontigenin (4), respectively. Among the isolated compounds, compounds 2-4 revealed the significant hepatoprotective effect in vitro when their $EC_{50}$ values compare with that of silybin, as a positive control. It also exhibited that emodin possessed the most hepatoprotective effect among these active compounds. In case of Osumogwa-Tang, its hot water extract showed the moderate protective effect on tacrine-induced cytotoxicity in Hep G2 cells. Hot water extract of Chaenomelis Fructus, one of the constituent herbal drug of this prescription, exhibited the significant hepatoprotective effect with $EC_{50}$ value of $7.8{\pm}0.1\;{\mu}g/ml$, however, it showed strong cytotoxicity in Hep G2 cells above the concentration of $25\;{\mu}g/ml$. It was revealed that both hot water extract of Evodiae Fructus and its butanol soluble fraction showed the moderate hepatoprotective effect but concentration-dependent activity in Hep G2 assay system. Two quinolone alkaloids, evocarpine and dihydroevocarpine, also tested for their hepatoprotective effects on tacrine-induced cytotoxicity in Hep G2 cells, however, these two compounds derived from the Evodiae Fructus as the major constituents did not show in vitro hepatoprotective effect. From these results, it would be necessary to further isolation of its hepatoprotective compounds from the butanol soluble fraction of the hot water extract of Evodiae Fructus.

동절기 옥외 노출 콘크리트의 동결융해 현상과 내구성 증진방안

이상현,김정진,성천우,Lee, Sang Hyun,Kim, Jung Jin,Sung, Cheon Woo 한국구조물진단유지관리공학회 2014 한국구조물진단유지관리공학회지 Vol.18 No.4

본 고는 동절기 이후 무근 콘크리트의 상부에서 쉽게 발생하는 스케일링 현상에 주목하여 무근 콘크리트의 동해 발생원인을 고찰하고, 이에 대한 내구성을 향상시키기 위한 방안을 기존문헌조사를 통하여 1) 강도향상, 2) 진공배수공법 적용, 3) 흡수방지재 시공의 방법을 선정하였다. 그 후 각 방법의 동결융해저항성 향상 평가를 정량적으로 평가하기위하여 동결융해 시험을 통한 상대동탄성계수를 측정하였다. 그 결과 1), 2)번의 경우 동탄성계수가 약 15% 향상, 3)의 경우 강도에 따라 7~13%향상됨을 실험적으로 확인하였다. 따라서 상기의 방법 모두 무근 콘크리트의 동결융해 저항성 향상에 유효한 방법으로 판단되며, 이를 통해 무근콘크리트의 빈번히 발생하는 품질저하 및 이로인한 유지보수비용 절감을 도모할 수 있을 것으로 사료된다.

IoT 보안을 위한 SHA-256 해시 프로세서의 면적 효율적인 설계

이상현,신경욱,Lee, Sang-Hyun,Shin, Kyung-Wook 한국정보통신학회 2018 한국정보통신학회논문지 Vol.22 No.1

전자서명, 인증 코드, 키 생성 알고리듬 등의 보안 프로토콜에 사용되는 SHA-256 해시 함수를 면적 효율적으로 설계하였다. 설계된 SHA-256 해시 프로세서는 입력 메시지에 대한 패딩 및 파싱 기능을 수행하는 패더 블록을 포함하여 프리프로세싱을 위한 소프트웨어 없이 동작하도록 구현하였다. 라운드 연산을 16-비트 데이터 패스로 구현하여 64 라운드 연산이 128 클록 주기에 처리되도록 하였으며, 이를 통해 저면적 구현과 함께 성능 대비 하드웨어 복잡도 (area per throughput; APT)를 최적화 하였다. 설계된 SHA-256 해시 프로세서는 Virtex5 FPGA로 구현하여 정상 동작함을 확인하였으며, 최대 116 MHz 클록 주파수로 동작하여 337 Mbps의 성능을 갖는 것으로 평가되었다. ASIC 구현을 위해 $0.18-{\mu}m$ CMOS 셀 라이브러리로 합성한 결과, 13,251 GE로 구현되었으며, 최대 동작주파수는 200 MHz로 예측되었다. This paper describes an area-efficient design of SHA-256 hash function that is widely used in various security protocols including digital signature, authentication code, key generation. The SHA-256 hash processor includes a padder block for padding and parsing input message, so that it can operate without software for preprocessing. Round function was designed with a 16-bit data-path that processed 64 round computations in 128 clock cycles, resulting in an optimized area per throughput (APT) performance as well as small area implementation. The SHA-256 hash processor was verified by FPGA implementation using Virtex5 device, and it was estimated that the throughput was 337 Mbps at maximum clock frequency of 116 MHz. The synthesis for ASIC implementation using a $0.18-{\mu}m$ CMOS cell library shows that it has 13,251 gate equivalents (GEs) and it can operate up to 200 MHz clock frequency.

복층터널 안정성 분석을 위한 빔-스프링 모델 개발

이상현,안준상,강경남,김병찬,송기일,Lee, Sang-Hyun,An, Joon-Sang,Kang, Kyung-Nam,Kim, Byung-Chan,Song, Ki-Il 한국터널지하공간학회 2017 한국터널지하공간학회논문집 Vol.19 No.2

In this study, as an initial study for development of stability analysis program of a double-deck tunnel during life cycle, a structural analysis solver based beam-spring model for the double-deck tunnel is constructed. Effect of parameters(slab supporting type, depth of the tunnel and ground elastic modulus) is analyzed with the beam-spring model. The model is also compared and verified by commercial structural analysis program. It is considered that the slab supporting type affects the integrated behavior with segment lining and influence of intermediate slab on the stability of the tunnel decreases as the tunnel depth increases. The relationship between the ground elastic modulus and the effect of the intermediate slab on the segment lining needs further investigation. 본 연구는 복층터널 생애전주기 안정성 평가 프로그램 개발을 위한 초기 연구로서, 복층터널 안전성 분석을 위한 빔-스프링 모델 기반의 구조해석 솔버를 개발하였다. 구축된 복층터널의 빔-스프링 모델을 사용하여 중간슬래브 지지방식, 터널심도 및 지반탄성계수가 복층터널의 안정성에 미치는 영향에 대하여 분석하였으며, 상용 구조해석 프로그램과 비교검토를 수행하였다. 중간슬래브의 지지방식은 세그먼트 라이닝과 일체화 거동에 영향을 미치고, 터널심도가 깊어질수록 중간슬래브가 복층터널의 안정성에 미치는 영향력이 상대적으로 작아지는 것으로 판단된다. 지반탄성계수와 중간슬래브가 세그먼트 라이닝 부재력 분포에 미치는 영향의 관계는 추가적인 연구가 필요할 것으로 판단된다.

Sol-gel법에 의한 박막태양전지용 CuInS₂ 박막의 증착과 특성

이상현,이승엽,박병옥,Lee, Sang-Hyun,Lee, Seung-Yup,Park, Byung-Ok 한국결정성장학회 2011 한국결정성장학회지 Vol.21 No.4

박막 태양전지의 저가 고효율화를 실현하기 위해 넓은 면적의 기판 위에 코팅이 가능하며 진공의 유자가 필요 없기 때문에 장치가 간단하고 고순도의 균질한 박막을 얻을 수 있고 박막의 조성을 쉽게 조절할 수 있는 Sol-Gel법을 이용 하였다. Se보다 저가이며 독성이 없고 풍부한 원료인 S로 치환하여 사용하며 Cu/In비 값을 조절하고 tetragonal chalcopyrite $CuInS_2$의 열처리 온도에 따른 박막의 구조적, 광학적 특성에 미치는 변수들의 영향을 알아보았다. XRD pattern을 관찰한 결과 Cu/In비가 1.0일 때 $2{\theta}=27.9^{\circ}$에서 주피크가 가장 강하게 나타났으며 (112) 방향의 배향성을 가진 chalcopyrite상임을 확언 할 수 있었다. 열처리 온도가 증가할수록 (112) 면의 강도가 커지며 $500^{\circ}C$에서 열처리를 한 $CuInS_2$ 박막은 tetragonal 구조의 화학량론적 $CuInS_2$ 특징을 나타내고 본 실험의 샘플의 격자상수를 측정한 값이 a = 5.5032, c = 11.1064 ${\AA}$이며 JCPDS(Joint Committee on Powder Diffraction Standards)에 보고된 데이터 a = 5.523, c = 11.14 ${\AA}$과 거의 일치하였다. 광학적 특성을 알아보기 위해 측정한 광투과율은 가시광선 영역(380~770 nm)에서 전체적으로 30% 이하로 나타났다. $CuInS_2$ thin films were prepared using a sol-gel spin-coating method. That makes large scale substrate coating, simple equipment, easy composition control available. The structural and optical properties of $CuInS_2$ thin films that include less toxic materials (S) instead of Se, tetragonal chalcopyrite structure. Copper acetate monohydrate ($Cu(CH_3COO)_2{\cdot}H2O$) and indium acetate ($In(CH_3COO)_3$) were dissolved into 2-propanol and l-propanol, respectively. The two solutions were mixed into a starting solution. The solution was dropped onto glass substrate, rotated at 3000 rpm, and dried at $300^{\circ}C$ for Cu-In as-grown films. The as-grown films were sulfurized inside a graphite container box and chalcopyrite phase of $CuInS_2$ was observed. To determine the optical properties measured optical transmittance of visible light region (380~770 nm) were less than 30 % in the overall. The XRD pattern shows that main peak was observed at Cu/In ratio 1.0 and its orientation was (112). As annealing temperature increases, the intensity of (112) plane increases. The unit cell constant are a = 5.5032 and c = 11.1064 $\AA$, and this was well matched with JCPDS card. The optical transmittance of visible region was below than 30 %.

Er:YAG laser를 조사한 치근면의 변화에 관한 연구

이상현,김영준,정현주,Lee, Sang-Hyun,Kim, Young-Jun,Chung, Hyun-Ju 대한치주과학회 2002 Journal of Periodontal & Implant Science Vol.32 No.2

This study was performed to evaluate the usability of Er:YAG laser for periodontal therapy. Forty dental root slabs ($5{\times}5{\times}2mm^3$) were prepared from human periodontally diseased extracted teeth and grouped into 4 groups: 1) control (root planing only), 2) root planing and irradiated with laser at 30mJ, 3) root planing and irradiated with laser at 60mJ, and 4) root planing and irradiated with laser at 100mJ. The root slabs were embedded in resin block before laser treatment. Er:YAG laser was irradiated under water irrigation with the tip held perpendicular to the root surface in contact mode. After Er:YAG laser irradiation or planing on the root surface, morphological changes have been observed under SEM, and the micro-hardness and Ca/P ratio were compared. 1. In the Control group, the root surface showed the directional change caused by root planing instrumentation, and the presence of smear layer, and no exposure of dentinal tubule was observed. Laser irradiated group showed surface changes with rough dentin surface of niche and depression and dentinal tubule exposure by the elimination of smear layer. 2. The micro-hardness of root surface in the laser irradiated group was higher than the control group. The higher energy output was applied, the higher micro-hardness on root surface was resulted. 3. The higher energy output was applied, the higher Ca/P ratio was observed. The higher Ca/P ratio in 60mJ group and 100mJ group was statistically significantly compared to the control group and the 30mJ group. These results suggest that Er:YAG laser irradiation on the periodontally diseased root surface could remove smear layer and increase the micro-hardness on root surface and Ca/P ratio which contribute to enhance the acid resistance of periodontally treated root surface.

타일-기반 수치지도를 이용한 동시 합병 처리기 설계 및 구현

이상현,김동현,홍봉희,Lee, Sang-Hyun,Kim, Dong-Hyun,Hong, Bong-Hee 한국공간정보학회 2000 개방형지리정보시스템학회 논문지 = Journal of the Korea Open Geogr Vol.2 No.1

기존에 제작되어 있는 수치지도를 이용해서 공간 데이타베이스를 구축할 때 타일 기반의 분리된 수치지도를 Seamless Map으로 다시 제작하는 과정은 필수적이다. 기존의 반복적인 합병 방법은 작업의 동시성이 떨어지는 문제점이 있다. 이 논문에서는 다수 작업자에 의한 작업의 동시성을 유지할 수 있도록 하는 변형된 2PC 프로토콜에 기반한 동시 합병 처리기의 구현에 대해 다루고 있다. 작업자들은 처리기를 통하여 서로 간의 작업을 공유할 수 있으므로 합의에 의한 합병 작업을 동시에 진행할 수 있다. To build a spatial database from digital maps, it is necessary to rebuild a seamless-map with discrete tile-based digital maps. The sequential merge methods have the disadvantage of degenerating concurrency. In this paper, we consider the implementation of the system based on modified 2PC protocol to retain the concurrent merge. As the engineers share the merge through the system, they can concurrently proceed to merge by negotiation.

지역 간 시계열 인구이동의 정량적 특징 분석 및 인구이동 네트워크의 연결중심성 분석

이상현,오윤경,Lee, Sang-Hyun,Oh, Yun-Gyeong 한국농공학회 2017 한국농공학회논문집 Vol.59 No.5

In this study, we visualized the regional migration in Korea from 2001 to 2015 using the Chord diagram which can represents amount of migration and flows at the same time. In addition, we constructed a migration network and analyzed the degree centrality of each region for identifying the main regions linking to various regions. In 2001~2005, most of population moved into Geonggi from various regions. However, the capital function was transferred to Sejong in 2011~2015, and population moving into Sejong and Chungnam was increased significantly. The main outflow of population in migration network were shown at the regions in Jeonbuk and Gyeongbuk province in 2001~2004, and recently the regions in Gyeongnam, Gyeonggi, and Seoul were identified as the main nodes in terms of outflow of population. We also focused on migration in rural area through degree centrality, and cord diagram in Chungnam, Jeonbuk, and Jeonnam where include the representative crop area. In 2015. there was the significant increase of migration from Gyeonggi to Chungnam, and internal migration within Jeonbuk increased rather than cross-border migration. In addition, migration from Jeonam to capital area decreased in 2015 but migration among cities within Jeonman increased. In particular, Yesan-gun showed the significant migration to other cities in Jeonnam. Population is necessary to develop community and sustain economic growth in rural regions. Therefore, migration is important for the transfer of manpower. The strength of this study is to approach the temporal change of migration from the viewpoint on quantitative and structural characteristics.

입력전류 파형 개선형 단상 정류기의 토폴로지

이상현(Sang-Hyun Lee),박진민(Jin-Min Park),문상필(Sang-Pil Mun),서기영(Ki-Young Suh) 한국조명·전기설비학회 2003 한국조명·전기설비학회 학술대회논문집 Vol.2003 No.-

For small capacity rectifier circuits such as these for consumer electronics and appliances, capacitor input type rectifier circuits are generally used. Consequently, various harmonics generated within the power system become a serious problem. Various studies of this effect have been presented previously. However, most of these employ switching devices, such as FETs and the like. The absence of switching devices makes systems more tolerant to over-load, and brings low radio noise benefits. We propose a power factor correction scheme using a LC resonant in commercial frequency without switching devices. In this method, it makes a sinusoidal wave by widening conduction period using the current resonance in commercial frequency, Hence the harmonic characteristics can be significantly improved, where the lower order harmonics, such as the fifth and seventh order are much reduced. The result are confirmed by the theoretical and experiment implementations.