• Preventive Nutrition and Food Science
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• 제10권2호
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• pp.172-178
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• 2005

Dandelions have been reported to have medicinal properties and bioactive components that impact human health. However, the precise biological properties of dandelions and the parts of the plants possessing bioactive components remain uncertain. In this study, we evaluated 3 different types of dandelions based on their cultivation origin (Songpa, Uiryung, and native Uiryung types) as well as their 4 different plant parts (leaf, flower, root, skin). Each sample was extracted with $80\%$ methanol and then compared for the biological activities (anti-oxidative, immune cell proliferative and tumor cell growth inhibitory activities). All 3 types of dandelions possessed a degree of biological functions including the hydroxyl radical scavenger activity, immune cell proliferative activity and tumor cell growth inhibitory activity. However, there was no significant difference in these activities between the 3 dandelion types. Leaves of all three dandelion types showed the highest levels of all biological activities. To a lesser degree, the flower and root parts displayed biological activities. In the skin parts, anti-oxidative activity was also detected only at higher doses of dandelion extracts. Heating the dandelion leaf extract did not affect the biological activity, suggesting a heat-stable nature of the biological compounds. Taken together, these collective data suggest that dandelions, in particular their leaves, possess a high concentration of heat-resistant biological compounds, which are responsible for anti-oxidative, immune cell proliferative and tumor cell growth-inhibitory activities.

• Journal of applied mathematics & informatics
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• 제26권1_2호
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• pp.355-364
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• 2008

Under pathological stress stimuli, dynamics of a biological system can be changed by alteration of several components such as functional proteins, ultimately leading to disease state. These dynamics in disease state can be modeled using differential equations in which kinetic or system parameters can be obtained from experimental data. One of the most effective ways to restore a particular disease state of biology system (i.e., cell, organ and organism) into the normal state makes optimization of the altered components usually represented by system parameters in the differential equations. There has been no such approach as far as we know. Here we show this approach with a cardiac hypertrophy model in which we obtain the existence of the optimal parameters and construct an optimal system which can be used to find the optimal parameters.

• Applied Biological Chemistry
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• 제36권4호
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• pp.239-243
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• 1993

탈지가자(Terminalia chebula Retz)에서 추출, 분리된 페놀성 항산화 물질의 화학구조를 MS 및 H-NMR을 이용하여 분석하였다. 가자의 유리형 페놀산 추출물에는 ferulic acid, vanillic acid 및 p-coumaric acid, 용성 에스테르형 페놀산에는 caffeic acid, vanillic acid 및 p-coumaric acid, 불용성 페놀산에는 caffeic acid, phloroglucinol 및 pyrogallol이 주된 항산화성 물질로 확인되었다.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1995년도 추계학술대회
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• pp.189-192
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• 1995

In Visually Evoked Potentials(VEP) or Auditory Evoked Potentials(AEP), the components by the stimulation and the components which are irrelevant to the stimulation(noise or nonstationary spontaneous EEG) are mixed together. So one should average hundreds of EP waves to extract the components by the stimulation only. In this study, we have classified EP's, which are the responses of the different stimulations and different states of subjects. To classify the EP waves, the cross-correlation coefficients and neural network method(error back propagation) are used and compared.

• Applied Biological Chemistry
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• 제34권4호
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• pp.312-317
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• 1991

선복화(旋覆花)의 휘발성(揮發性) 성분(成分)을 동정(同定)하기 위하여 국내산(國內産) 및 중국산(中國産)을 시료(試料)로 사용(使用)하였다. 휘발성(揮發性) 성분(成分) 포집(捕集)은 SDE 방법(方法)을 사용(使用)하여 건조(乾燥)된 시료(試料) 100g중 국내산(國內産) 155.3 mg 중국산(中國産) 101.6 mg을 얻었다. 포집(捕集)된 휘발성(揮發性) 성분(成分)을 GC 및 GC/MS를 이용(利用)하여 hydrocarbon 류(類) 10, aldehyde 류(類) 7, alcohol 류(類) 18, ketone 류(類) 3, ester 류(類) 5, acid 류(類) 13 및 miscellaneous compounds 6 성분(成分)으로 모두 62 성분(成分)을 동정(同定)하였다. 또한, 이들 성분(成分)을 좀 더 세밀(細密)히 검토(檢討)코자 silica gel column chromatography에 의해 용출용매(溶出溶媒)의 극성(極性)을 변화(變化)시킴으로 성분조성(成分組成)을 세분(細分)하였다. 그 결과(結果) 국내산(國內産) 선복화(旋覆花)의 휘발성(揮發成) 성분중(成分中) 탄화수소(炭化水素) 화합물(化合物) 분획(分劃)이 16.85% 함산소화합물(含酸素化合物) 분획(分劃)이 83.15%이며, 중국산(中國産) 선복화(旋覆花)는 탄화수소(炭化水素) 화합물(化合物) 분획(分劃)이 23.46% 함산소화합물(含酸素化合物) 분획(分劃)이 76.53%를 함유(含有)하고 있다.

• Journal of Applied Biological Chemistry
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• 제62권1호
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• pp.109-109
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• 2019

• Biotechnology and Bioprocess Engineering:BBE
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• 제11권4호
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• pp.288-292
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• 2006

Through statistically designed experiments, lysis agents were optimized to effectively disrupt bacterial cells in a microfluidic device. Most surfactants caused the efficient lysis of Gram-positive microbes, but not of Gram-negative bacteria. A Plackett-Burman design was used to select the components that increase the efficiency of the lysis of the Gram-negative bacteria Escherichia coli. Using this experimental design, both lysozyme and benzalkonium chloride were shown to significantly increase the cell lysis efficiency, and ATP was extracted in proportion to the lysis efficiency. Benzalkonium chloride affected the cell membrane physically, while lysozyme destroyed the cell wall, and the amount of ATP extracted increased through the synergistic interaction of these two components. The two-factor response-surface design method was used to determine the optimum concentrations of lysozyme and benzalkonium chloride, which were found to be 202 and 99 ppm, respectively. The lysis effect was further verified by microscopic observations in the microchannels. These results indicate that Gram-negative cells can be lysed efficiently in a microfluidic device, thereby allowing the rapid detection of bacterial cells using a bioluminescence-based assay of the released ATP.

• Journal of Electrochemical Science and Technology
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• 제9권2호
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• pp.141-148
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• 2018

This study evaluated the performance characteristics of varied electrolyte species and amounts in a molten carbonate fuel cell (MCFC). Coin-type MCFCs were used at the condition of $650^{\circ}C$ and 1 atm. In order to measure the effects of varied electrolyte species and amounts, electrolytes of $(Li+K)_2CO_3$ and $(Li+Na)_2CO_3$ were selected and the amounts of 1.5 g, 2.0 g, 3.0 g, and 4.0 g were used. Insignificant performance differences were observed in the cell using different electrolytes, but the cell performance was sensitive to the amount of the electrolyte used. The pore-filling ratio (PFR), a ratio of pore filling in the components by the liquid carbonate electrolytes, was used to determine the optimum performance range. Consequently, 77% PFR demonstrated the optimum performance for both electrolytes. Thus, the MCFC had a permissible but narrow optimum performance range. The remaining amounts of electrolyte in the cells were determined using the weight reduction ratio (WRR) method after several hours of cell operation. The WRR used the relationship between the initial loaded amount of electrolyte and weight reduction of components in 10 wt% acetic acid. The relationships were linear and identical between the two electrolyte species.

• Journal of Applied Biological Chemistry
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• 제62권4호
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• pp.367-374
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• 2019

Euphorbia humifusa Willd (EuH), called Ttang-Bin-Dae in Korea, is a traditional medicinal plant widely used for its anti-inflammatory and antiviral activity. Ethyl acetate (EA) extracts of EuH (EA/EuH) inhibit invasion and metastasis by inhibiting tumor necrosis factor TNFá-induced matrix metalloproteinases (MMP)-9 expression in human breast cancer cells. However, the bioactive components of EA/EuH mediating the inhibition of MMP-9 expression have not been identified. In the present study, three bioactive constituents of EA/EuH were isolated using high-performance liquid chromatography. Nuclear magnetic resonance spectroscopy revealed isoquercetin, avicularin, and astragalin as the bioactive compounds responsible for preventing TNFα-induced MMP-9 mRNA expression in breast cancer cells. These findings suggest that isoquercetin, avicularin, and astragalin could be used as valuable anti-metastatic agents against metastatic cancers.

• Molecules and Cells
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• 제45권9호
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• pp.603-609
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• 2022

Cells can communicate in a variety of ways, such as by contacting each other or by secreting certain factors. Recently, extracellular vesicles (EVs) have been proposed to be mediators of cell communication. EVs are small vesicles with a lipid bilayer membrane that are secreted by cells and contain DNA, RNAs, lipids, and proteins. These EVs are secreted from various cell types and can migrate and be internalized by recipient cells that are the same or different than those that secrete them. EVs harboring various components are involved in regulating gene expression in recipient cells. These EVs may also play important roles in the senescence of cells and the accumulation of senescent cells in the body. Studies on the function of EVs in senescent cells and the mechanisms through which nonsenescent and senescent cells communicate through EVs are being actively conducted. Here, we summarize studies suggesting that EVs secreted from senescent cells can promote the senescence of other cells and that EVs secreted from nonsenescent cells can rejuvenate senescent cells. In addition, we discuss the functional components (proteins, RNAs, and other molecules) enclosed in EVs that enter recipient cells.