펜틸렌테트라졸 투여 흰쥐에서의 천마의 항경련 작용기전

허근,김진숙,권태협,김정애,용철순,하정희,이동웅 영남대학교 약품개발연구소 1998 영남대학교 약품개발연구소 연구업적집 Vol.8 No.-

Gastrodia elata (GE) is a oriental medicinal herb which has been used traditionally for the treatment of various brain diseases including convulsion and epilepsy. In order to examine the mechanism of anticonvulsive effect, we treated the methanol extract of GE (500 mg/kg, P.O) to the pentylenetetrazole (PTZ)-induced convulsive rats. Methanol extracts of GE siginificantly inhibited (35%) the convulsion state as well as the level of lipid peroxidation (25%) in the brain. The ether fraction of methanol extracts among the others effectively inhibited in vitro lipid peroxidation dose dependently (5.0×10^(-6)~2.0×10^(-5) g/ml). The scavenging effect on hydroxy radicals was found in all the fractions of ether, butanol, and dichloromethane. These results suggest that the anticonvulsive effect of GE is possibly due to the antioxidative effects of the active components in GE.

Forest Canopy Density Estimation Using Airborne Hyperspectral Data

( Tae Hyub Kwon ),( Woo Kyun Lee ),( Doo Ahn Kwak ),( Tae Jin Park ),( Jong Yoel Lee ),( Suk Young Hong ),( Cui Guishan ),( So Ra Kim ) 대한원격탐사학회 2012 大韓遠隔探査學會誌 Vol.28 No.3

This study was performed to estimate forest canopy density (FCD) using airborne hyperspectral data acquired in the Independence Hall of Korea in central Korea. The airborne hyperspectral data were obtained with 36 narrow spectrum ranges of visible (Red, Green, and Blue) and near infrared spectrum (NIR) scope. The FCD mapping model developed by the International Tropical Timber Organization (ITTO) uses vegetation index (VI), bare soil index (BI), shadow index (SI), and temperature index (TI) for estimating FCD. Vegetation density (VD) was calculated through the integration of VI and BI, and scaled shadow index (SSI) was extracted from SI after the detection of black soil by TI. Finally, the FCD was estimated with VD and SSI. For the estimation of FCD in this study, VI and SI were extracted from hyperspectral data. But BI and TI were not available from hyperspectral data. Hyperspectral data makes the numerous combination of each band for calculating VI and SI. Therefore, the principal component analysis (PCA) was performed to find which band combinations are explanatory. This study showed that forest canopy density can be efficiently estimated with the help of airborne hyperspectral data. Our result showed that most forest area had 60 ~ 80% canopy density. On the other hand, there was little area of 10 ~ 20% canopy density forest.

Forest Canopy Density Estimation Using Airborne Hyperspectral Data

Kwon, Tae-Hyub,Lee, Woo-Kyun,Kwak, Doo-Ahn,Park, Tae-Jin,Lee, Jong-Yoel,Hong, Suk-Young,Guishan, Cui,Kim, So-Ra The Korean Society of Remote Sensing 2012 大韓遠隔探査學會誌 Vol.28 No.3

This study was performed to estimate forest canopy density (FCD) using airborne hyperspectral data acquired in the Independence Hall of Korea in central Korea. The airborne hyperspectral data were obtained with 36 narrow spectrum ranges of visible (Red, Green, and Blue) and near infrared spectrum (NIR) scope. The FCD mapping model developed by the International Tropical Timber Organization (ITTO) uses vegetation index (VI), bare soil index (BI), shadow index (SI), and temperature index (TI) for estimating FCD. Vegetation density (VD) was calculated through the integration of VI and BI, and scaled shadow index (SSI) was extracted from SI after the detection of black soil by TI. Finally, the FCD was estimated with VD and SSI. For the estimation of FCD in this study, VI and SI were extracted from hyperspectral data. But BI and TI were not available from hyperspectral data. Hyperspectral data makes the numerous combination of each band for calculating VI and SI. Therefore, the principal component analysis (PCA) was performed to find which band combinations are explanatory. This study showed that forest canopy density can be efficiently estimated with the help of airborne hyperspectral data. Our result showed that most forest area had 60 ~ 80% canopy density. On the other hand, there was little area of 10 ~ 20% canopy density forest.

Continuous Control of Charge Transport in Bi‐Deficient BiFeO₃ Films Through Local Ferroelectric Switching

Kim, Tae Heon,Jeon, Byung Chul,Min, Taeyoon,Yang, Sang Mo,Lee, Daesu,Kim, Yong Su,Baek, Seung‐,Hyub,Saenrang, Wittawat,Eom, Chang‐,Beom,Song, Tae Kwon,Yoon, Jong‐,Gul,Noh, Tae Won WILEY‐VCH Verlag 2012 Advanced Functional Materials Vol.22 No.23

<P><B>Abstract</B></P><P>It is demonstrated that electric transport in Bi‐deficient Bi<SUB>1‐<I>δ</I></SUB>FeO<SUB>3</SUB> ferroelectric thin films, which act as a p‐type semiconductor, can be continuously and reversibly controlled by manipulating ferroelectric domains. Ferroelectric domain configuration is modified by applying a weak voltage stress to Pt/Bi<SUB>1‐<I>δ</I></SUB>FeO<SUB>3</SUB>/SrRuO<SUB>3</SUB> thin‐film capacitors. This results in diode behavior in macroscopic charge‐transport properties as well as shrinkage of polarization‐voltage hysteresis loops. The forward current density depends on the voltage stress time controlling the domain configuration in the Bi<SUB>1‐<I>δ</I></SUB>FeO<SUB>3</SUB> film. Piezoresponse force microscopy shows that the density of head‐to‐head/tail‐to‐tail unpenetrating local domains created by the voltage stress is directly related to the continuous modification of the charge transport and the diode effect. The control of charge transport is discussed in conjunction with polarization‐dependent interfacial barriers and charge trapping at the non‐neutral domain walls of unpenetrating tail‐to‐tail domains. Because domain walls in Bi<SUB>1‐<I>δ</I></SUB>FeO<SUB>3</SUB> act as local conducting paths for charge transport, the domain‐wall‐mediated charge transport can be extended to ferroelectric resistive nonvolatile memories and nanochannel field‐effect transistors with high performances conceptually.</P>

REDD+ 모니터링 시스템 구축을 위한 원격탐사기술의 활용방안

박태진 ( Tae Jin Park ),이우균 ( Woo Kyun Lee ),정래선 ( Rae Sun Jung ),김문일 ( Moon Il Kim ),권태협 ( Tae Hyub Kwon ) 한국임학회 2011 한국산림과학회지 Vol.100 No.3

최근 기후변화와 관련하여 국내를 비롯한 국제적인 관심이 증폭되고 있으며, 이러한 시대적인 흐름 속에 탄소흡수원으로서의 산림의 중요성이 부각되고 있다. 특히, 산림전용 및 황폐화 방지를 통한 온실가스감축(Reduced Emissions from Deforestation and Degradation, REDD) 및 산림탄소축적보존 및 증진, 지속가능한 산림경영을 포함하는 REDD+가 post-2012에 이행될 신규 메커니즘으로 활용될 전망이다. 메커니즘의 이행을 위해서는 기본적으로 MRV(Measuring, Reporting and Verification) 시스템을 통해 메커니즘 적용 효과를 인증 받아야 한다. 본 연구에서는 가장 효율적인 모니터링 방법 중 하나로 인정받고 있는 다양한 원격탐사기술의 토지피복변화 탐지 및 탄소축적량 추정하는 방법 및 효과를 비용 및 기술(불확실성)측면에서 분석하였다. 그 결과 토지피복변화탐지를 위해서는 중해상도 광학영상 및 위성 탑재 SAR(Synthetic Aperture Radar)가 가장 적합한 원격탐사자료로 도출되었다. 그리고 탄소축적량 추정에 있어서는, 항공기 탑재 LiDAR(Light Detection and Ranging), SAR와 같이 불확실성이 낮은 기술과 비용효율적인 기술인 중해상도 광학영상, 위성 탑재 SAR 간의 통합을 통해 효율적인 결과를 도출할 수 있음을 확인 할 수 있었다. 하지만, 아직까지 본 메커니즘에 대한 명확한 인증기관, 가이드라인 및 불확실성에 대한 기준이 결정되지 않고 있으므로, 추후 지속적인 관심을 통해 국제적인 흐름을 파악하고, 적합한 방법론을 구축해야 한다. 뿐만 아니라 개발된 메커니즘을 대상 개도국에 활용하기 위해서는 긴밀한 국제협력관계 구축 및 대상국에 적합한 모니터링 방법 또한 고려해야 할 필요성이 있다. In recent years, domestic and international interests focus on climate change, and importance of forest as carbon sink have been also increased. Particularly REDD+ mechanism expanded from REDD(Reduced Emissions from Deforestation and Degradation) is expected to perform a new mechanism for reducing greenhouse gas in post 2012. To conduct this mechanism, countries which try to get a carbon credit have to certify effectiveness of their activities by MRV(Measuring, Reporting and Verification) system. This study analyzed the approaches for detecting land cover change and estimating carbon stock by remote sensing technology which is considered as the effective method to develop MRV system. The most appropriate remote sensing for detection of land cover change is optical medium resolution sensors and satellite SAR(Synthetic Aperture Radar) according to cost efficiency and uncertainty assessment. In case of estimating carbon stock, integration of low uncertainty techniques, airborne LiDAR(Light Detection and Ranging), SAR, and cost efficient techniques, optical medium resolution sensors and satellite SAR, could be more appropriate. However, due to absence of certificate authority, guideline, and standard of uncertainty, we should pay continuously our attention on international information flow and establish appropriate methods. Moreover, to apply monitoring system to developing countries, close collaboration and monitoring method reflected characteristics of each countries should be considered.

복합 항암 화학요법 후 HBsAg 양성 악성림프종환자의 임상경과

구본권(Bon Kwon Ku),한지숙(Jee Sook Hahn),한광협(Kwang Hyub Hahn),이승태(Seung Tae Lee),서형찬(Hyung Chan Suh),권건호(Kun Ho Kwon),이진헌(Jin Hun Lee),민유홍(Yoo Hong Min),고윤웅(Yun Woong Ko) 대한내과학회 1997 대한내과학회지 Vol.52 No.4

N/A Objectives: Infection and replication of the hepatitis B virus are closely related to the host imm- unity. Anticancer chemotherapy decreases the immune response of the host, Especially, glucocorticoid can activate the replication of hepatitis B virus directly. It is well known that hepatitis B virus infection and hepatic complications are more common in patients with hematologic malignancies like malignant lymphoma. We studied the incidence of hepatitis B virus infection and hepatic complications following anti- cancer chemotherapy in patients with malignant lymphoma. Methods: Among 224 cases diagnosed as malignant lymphoma from January 1989 to December 1993 at Yonsei University Medical Center, 77 cases tested for hepatitis B virus serology was studied. Results: 1) Eighteen cases (23%) was HBsAg positive. 2) The results of hepatitis C virus serology in six cases were all negative. 3) Eight (57%) of 14 follow-up cases had hepatic complications, Two patients had fulminant hepatitis, two nonicteric hepatitis and four icteric hepatitis. 4) Interferon-alpha was administered in three cases among the patients with hepatic complications. Loss of HBeAg was observed in one case and loss of HBsAg in another case. Conclusion: Serious hepatic complications can be occurred following anticancer chemotherapy in HBsAg-positive patients with malignant lymphoma. Therefore, we recommend that patients being considered as candidates for anticancer chemotherapy should routinely undergo serologic test for Hepatitis B virus. In addition HBsAg-positive patients with anticancer chemotherapy should be regularly monitored for hepatic injury. And with the careful use of steroid and interferon, prolongation of survival might be searched for these patients.

Role of the Hepatic Xanthine Oxidase in Thyroid Oysfunction : Effect of Thyroid Hormones in Oxidative Stress in Rat Liver 흰쥐 간에서의 산화적 조직 손상에 대한 Thyroid 호르몬의 효과

Huh, Keun,Kwon, Tae-Hyub,Kim, Jin-Sook,Park, Jong Min 영남대학교 약품개발연구소 1998 영남대학교 약품개발연구소 연구업적집 Vol.8 No.-

The effect of thyroid hormones on the hepatic xanthine oxidase activity was studied in rats after the intraperitoneal injections of comthyroid (triiodotyronine : thyroxine=1 : 4) at 0.3 mg/kg for 3 consecutive days. The aim of this study was to understand the precise mechanism of hyperthyroidism induced by oxidative stress. The concentration of lipid peroxides determined indirectly by the measurement of thiobarbituric acid reactants was increased in comthyroid treated rats. The hepatic glutathione content was decreased in comthyroid injected rat compared to the euthyroid state. It was also observed that the increment of xanthine oxidase activity has a profound role in oxygen radicals generation system in comthyroid treated rat. These findings suggest that the enhanced xanthine oxidase activity and depleting glutathione content in comthyroid treated rats result in pathophysiological oxidative stress including an increment of hepatic lipid peroxidation.

Therapeutic Effect of Rebamipide on Ammonia-induced Gastric Mucosal Hemorrhagic Lesion in Rats

Huh, Keun,Kwon, Tae-Hyub,Kim, Soo-Kyun,Kim, Jin-Sook,Shin, Uk-Seob 영남대학교 약품개발연구소 1998 영남대학교 약품개발연구소 연구업적집 Vol.8 No.-

Rebamipide, 2-(4-chlorobenzoylamino)-3-[2(1H)-quinolinone-4-yl]-propionic acid, a novel antipeptic ulcer agent, has been reported to prevent various acute experimental gastric mucosal lesions and to accelerate the healing of chronic ulcers. Therapeutic effect of rebamipide was investigated with regard to the inhibitory effect on xanthine oxidase activity and type conversion of the enzyme which play a profound role in oxygen radicals generation system. Intraperitoneal administration of rebamipide at 60 mg/kg body weight reduced the xanthine oxidase activity, lipid peroxide content in ammonia induced hemorrhagic lesion. These results suggest that the therapeutic effect of rebamipide on gastric mucosal lesion may be in part due to the inhibitory activity of xanthine oxidase and type conversion rate of the enzyme.

비비례 모델 적용을 통한 곱셈적 사고와 나눗셈 학업성취도 향상 분석

좌승협(Seung-Hyub Jwa),손태권(Tae-Kwon Son),송다솜(Da-Som Song),이광호(Kwang-Ho Lee) 한국교원대학교 뇌기반교육연구소 2020 Brain, Digital, & Learning Vol.10 No.4

The proportional model and the non-proportional model are suggested in the mathematics curriculum as one of the tools to help mathematical understanding, but in Korea, the arithmetic algorithm is only introduced through the proportional model. This study analyzed the degree of multiplication thinking and division academic achievement of 3rd grade students through the application of proportional and non-proportional models. As a result of the study, the experimental group that applied both the proportional model and the non-proportional model significantly improved the multiplicative thinking level and division academic achievement compared to the comparative group. These results indicate that division learning using the proportional model and the proportional model together is more effective. Through these results, we suggested some conclusions and implications for improving division learning and teaching.

Effect of Thyroid Hormones in Oxidative Stress in Rat Liver

Huh, Keun,Kwon, Tae-Hyub,Kim, Jin-Sook,Park, Jon-Min The Pharmaceutical Society of Korea 1998 Archives of Pharmacal Research Vol.21 No.3

The effect of thyroid hormones on the hepatic xanthine oxidase activity was studied in rats after the intraperitoneal injections of comthyroid (triiodotyronine:thyroxine=1:4) at 0.3 mg/kg for 3 consecutive days. The aim of this study was to understand the precise mechanism of hyperthyroidism induced by oxidative stress. The concentration of lipid peroxides determined indirectly by the measurement of thiobarbituric acid reactants was increased in comthyroid treated rats. The hepatic glutathione content was decreased in comthyroid injected rat compared to the euthyroid state. It was also observed that the increment of xanthine oxidase activity has a profound role in oxygen radicals generation system in comthyroid treated rat. These findings suggest that the enhanced xanthine oxidase activity and depleting glutathione content in comthyroid treated rats result in pathophysiological oxidative stress including an increment of hepatic lipid peroxidation.