• 대한의용생체공학회:의공학회지
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• 제29권1호
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• pp.73-81
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• 2008

The purpose of this study is to observe the brain activity patterns during visual oddball tasks with two difficulty levels by the analysis of high-density event-related potential (ERP). Along with conventional statistical analysis of averaged ERP waveforms, we applied independent component analysis (ICA) for the individual, single-trial analysis and verified its effectiveness. We could identify multiple ERP components such as early visual components (P1, N1), and two components which seem to be important task-related components and showed difficulty-dependent variability (P2, P300). The P2 was found around central region at $180{\sim}220ms$, and the P300 was found globally at $300{\sim}500ms$ poststimulus. As the task became difficult, the P2 amplitude increased, and the P300 amplitude decreased. After single-trial ERPs were decomposed into multiple independent components (ICs), several ICs resulting from P2 and P300 sources were identified. These ICs were projected onto scalp electrodes and the projected ICs were statistically compared according to two task difficulties. For most subjects, the results obtained from single-trial/individual analysis using ICA gave the tendencies of amplitude change that are similar to the averaged ERP analysis for most subjects. The temporal pattern and number of ICs corresponding to ${\mu}$ rhythm was not dependent on the task difficulty. It seems that the motor response was not affected by the task difficulty.

• 대한의용생체공학회:의공학회지
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• 제40권6호
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• pp.223-229
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• 2019

The number of knee-related disease patients and knee joint surgeries is steadily increasing every year, and for knee rehabilitation training for these knee joint patients, it is necessary to strengthen the muscle of vastus medialis and quadriceps femoris. However, because of the cost and time-consuming difficulties of receiving regular hospital treatment in the course of knee rehabilitation, we developed knee exoskeleton using rapid prototype for knee rehabilitation with feedback from the electromyogram (EMG) and inertia motion unit (IMU) sensor. The modules was built on the basis of EMG and an IMU sensor applied complementary filter, measuring muscle activity in the vastus medialis and the range of joint operation of the knee, and then performing the game based on this measurement. The IMU sensor performed up to 97.2% accuracy in experiments with ten subjects. The functional game contents consisted of an exergaming platform based on EMG and IMU for the real-time monitoring and performance assessment of personalized isometric and isotonic exercises. This study combined EMG and IMU-based functional game with knee rehabilitation training to enable voluntary rehabilitation training by providing immediate feedback to patients through biometric information, thereby enhancing muscle strength efficiency of rehabilitation.

• 한국지하수토양환경학회지:지하수토양환경
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• 제11권3호
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• pp.66-77
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• 2006

최근에 적용된 지하수 미생물의 군집구조를 밝히는 분자생물학적 및 생화학적 방법들에 대해서 알아보았고 그 결과로서 지하수의 주요 오염물질에 따른 활성화된 미생물군집들이 무엇인지를 밝힌 연구논문들을 종합하여 정리하였다. PCR에 의한 유전자 증폭기술의 발달로 배양 없이 미생물 종류와 개체군을 파악할 수 있게 되었고 각종 finger-printing 방법 (DGGE, SSCP, RISA, microarray) 과 지방산분석법 (PLFA/FAME)을 이용하여 활성화 된 미생물군집구조를 분석하였으며 FISH 등의 방법으로 특정균의 활성도를 알아본 사례들을 조사하였다. 대표적인 지하수오염물질인 유류성분 (n-alkanes, BTEX, MTBE, ethanol)과 염소계 용매 (TCE, PCE, PCB, CE, carbon tetrachloride, chloro-benzene) 등으로 오염되었을 때 우점하는 지하수 미생물상에 대해 보고된 내용을 포함하였다.

• The Plant Pathology Journal
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• 제27권1호
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• pp.59-67
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• 2011

A bacterial strain CH-67 which exhibits antagonism towards several plant pathogenic fungi such as Botrytis cinerea, Fulvia fulva, Rhizoctonia solani, Sclerotinia sclerotiorum, Colletotrichum sp. and Phytophthora sp. was isolated from forest soil by a chitin-baiting method. This strain was identified as Burkholderia cepacia complex (Bcc) and belonging to genomovar IX (Burkholderia pyrrocinia) by colony morphology, biochemical traits and molecular method like 16S rRNA and recA gene analysis. This strain was used to develop a bio-fungicide for the control of tomato leaf mold caused by Fulvia fulva. Various formulations of B. pyrrocinia CH-67 were prepared using fermentation cultures of the bacterium in rice oil medium. The result of pot experiments led to selection of the wettable powder formulation CH67-C containing modified starch as the best formulation for the control of tomato leaf mold. CH67-C, at 100-fold dilution, showed a control value of 85% against tomato leaf mold. Its disease control efficacy was not significantly different from that of the chemical fungicide triflumidazole. B. pyrrocinia CH-67 was also effective in controlling damping-off caused by Rhizoctonia solani PY-1 in crisphead lettuce and tomato plants. CH67-C formulation was recognized as a cell-free formulation since B. pyrrocinia CH-67 was all lethal during formulation process. This study provides an effective biocontrol formulation of biofungicide using B. pyrrocinia CH-67 to control tomato leaf mold and damping-off crisphead lettuce and tomato.

• 생약학회지
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• 제48권2호
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• pp.97-107
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• 2017

There is no doubt that the effect of ginseng on blood pressure could be different depending upon the type of ginseng employed for the experiment and methodology, thereby can exert bilateral modulatory activity on blood pressure. It has been reported that ginseng induced no significant change in blood pressure in those subjects with normal blood pressure, but had a normalizing effect on the subjects with abnormal blood pressure. Especially, experimental evidence indicates that ginsenoside Rg3, a major component of red ginseng, has been found to lower blood pressure, which is mediated by release of endothelium-derived NO, enhancing the accumulation of cGMP in the rat aorta. This clinical results further support the beneficial effect of Korean ginseng on blood pressure elucidated by animal experiment. As expected, a multicentric non-controlled clinical study shows that the effect of ginseng consumption has been found to normalize blood pressure in hypertensive or hypotensive individuals as compared to virtually no effect in normotensives. In addition, ginseng has been known to exhibit blood pressure decreased with no significant side effect and deteriorated QOL during the combination therapy of ginseng and anti-hypertensive drugs. This review provides a comprehensive overview on the effects of Korean ginseng on blood pressure.

• 한국약용작물학회지
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• 제15권1호
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• pp.6-11
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• 2007

작약의 지상부인 잎과 줄기에서 물질을 분리 동정하기 위해 MeOH 추출 및 column chromatograpy하여 단일 물질 5종을 분리하였으며, 분리한 물질에 대하여 IR, UV, Mass, NMR 등을 이용하여 화학구조를 동정하였다. 그 결과 oleanolic acid, kaempferol, methyl gallate, astragalin, paeoniflorin의 구조가 확인되었으며 이들 화합물은 작약의 지상부인 잎과 줄기에서는 처음으로 분리되었다.

• 한국균학회지
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• 제29권2호
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• pp.104-109
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• 2001

Polyphosphate의 Candida albicans와 Trichophyton mentagrophytes에 대한 항진균 작용에 대하여 연구하였다. 평균 사슬길이가 15, 45, 75인 polyphosphate는 진균에 대하여 성장억제 효과를 나타낸 반면, pyrophosphate는 성장억제 효과가 없었다. 사슬길이가 증가함에 따라서 진균 성장억제 효과가 증가하는 것으로 관찰되었으며 $800\;{\mu}g/ml$ 농도에서는 균주의 성장을 완전히 억제시켰다. $Mg^{2+}$나 $Ca^{2+}$의 첨가는 polyphosphate의 성장억제 효과를 감소시켰다. Polyphosphate를 처리한 C. albicans에서는 핵산물질의 유리가 관찰되었으며, 세포 swelling이나 표면돌출과 같은 세포형태 변화도 관찰되었다. 세포막 불투과성 물질인 propidium iodide는 Polyphosphate를 처리한 C. albicans의 핵을 염색하는 것이 관찰되었다. Polyphosphate의 항진균 작용은 polyphosphate가 진균 세포벽이나 세포막의 필수 양이온에 대한 chelation 효과에 의한 것으로 사려된다.

• Toxicological Research
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• 제30권3호
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• pp.211-220
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• 2014

Resveratrol has received considerable attention as a polyphenol with various biological effects such as anti-inflammatory, anti-oxidant, anti-mutagenic, anti-carcinogenic, and cardioprotective properties. As part of the overall safety assessment of HS-1793, a novel resveratrol analogue free from the restriction of metabolic instability and the high dose requirement of resveratrol, we assessed genotoxicity in three in vitro assays: a bacterial mutation assay, a comet assay, and a chromosomal aberration assay. In the bacterial reverse mutation assay, HS-1793 did not increase revertant colony numbers in S. typhimurium strains (TA98, TA100, TA1535 and TA1537) or an E. coli strain (WP2 uvrA) regardless of metabolic activation. HS-1793 showed no evidence of genotoxic activity such as DNA damage on L5178Y $Tk^{+/-}$ mouse lymphoma cells with or without the S9 mix in the in vitro comet assay. No statistically significant differences in the incidence of chromosomal aberrations following HS-1793 treatment was observed on Chinese hamster lung cells exposed with or without the S9 mix. These results provide additional evidence that HS-1793 is non-genotoxic at the dose tested in three standard tests and further supports the generally recognized as safe determination of HS-1793 during early drug development.

• 생명과학회지
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• 제23권11호
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• pp.1381-1387
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• 2013

국내에서 식품으로 사용되고 있는 국화과 식물인 곤달비(Ligularia stenocephala) 잎과 뿌리의 생물활성을 과학적으로 검증하기 위하여 각 추출물에 대하여 항산화 활성 및 세포독성을 in vitro에서, 간보호 효과, 알코올 해독작용 및 기억증진 효능 등을 in vivo에서 평가하였으며 잎의 독특한 향기성분을 GC-MS로 분석하였다. 지질과산화 억제효과는 잎(20.4% 억제율)이 뿌리 보다 좋았으며, 유해 라디칼의 일종인 superoxide anion은 뿌리에서 생성 억제효과가 더 좋았고, DPPH 소거활성은 잎과 뿌리 모두 77~79%로 매우 뛰어났다. 사염화탄소로 유발된 급성 간독성 개선효과를 AST와 ALT 효소활성도를 지표로 확인한 결과, 잎의 ALT 억제활성이 대조군에 비해 약 78% 정도 감소하였으며 알코올을 투여한 mouse의 혈중 알코올 농도는 잎추출물 투여시 약 60% 가량 유의성 있게 감소되어 효과를 인정할 수 있었다. 세포독성은 뿌리에서 비교적 강하게 나타났는데, 흑색종의 경우, $IC_{50}=40.14mg/ml$이었으며, 잎의 세포독성은 비교적 약하였다. 기억증진 효과를 동물모델을 이용한 수동회피시험법으로 평가한 결과, 잎과 뿌리 모두 scopolamine에 의해 유도된 기억력 감소를 80% 이상 향상시킨 것으로 조사되었다. 곤달비 잎의 n-헥산 추출물을 GC-MS로 분석한 결과, 독특한 향기는 주로 terpene 화합물에서 유래되는 것으로 추정되었다.

• 생태와환경
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• 제35권4호통권100호
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• pp.326-330
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• 2002

습지토양을 두 가지 방법으로 멸균한 후, 미생물 효소활성도의 변화를 알아보았다. 단기 멸균의 효과는 톨루엔을 가하여 알아 보았고, 장기적인 효과는 감마선 조사를 이용하였다. 처리된 시료에서 ${\beta}$-glucosidase, ${\beta}$-xylosidase, cellobiohydrolase, phosphatase, arylsulfatase, N -acetylglucosaminidase 활성도를 methylumbelliferyl 계열의 인공기질을 사용하여 측정한 후 공시료와 비교하였다. 톨루엔을 가한 경우 효소에 따라 다른 반응을 보였다. 예를 들어, 처리에 의하여phosphatase의 활성은 증가하였으나 반대로 ${\beta}$-glucosidase와 arylsulfatasem의 활성도는 감소하였다. 감마선 조사는 모든 효소의 활성을 40-80%정도 감소시켰다. 본 연구의 전반적인 결과에 의하면, 적어도 단기적으로는 다량의 효소가 미생물 체외에서 안정적으로 존재하나, 장기적으로는de-novo 합성이 중요함을 알 수 있었다.