• 한국항해항만학회:학술대회논문집
• /
• 한국항해항만학회 1998년도 추계학술대회논문집:21세기에 대비한 지능형 통합항만관리
• /
• pp.263-269
• /
• 1998

The forecasting of container cargo volumes should be estimated correctly because it has a key roles on the establishment of port development planning, and the decision of port operating system. Container cargo volumes have a dynamic characteristics which was changed by effect of competitive ports. Accordingly forecasting was needed overall approach about competitive port's development, alternation and information. But, until now, traffic forecasting was not executed according to competitive situation, and that was accomplished at the point of unit port. Generally, considering the competition situation, simulation method was desirable at forecasting because system's scale was increased, and the influence power was intensified. In this paper, considering this situation, the objectives can be outlined as follows. 1) Structural model constructs by System dynamics method. 2) Structural simulation model develops according to modelling of competitive situation by expended SD method which included HEP(Hierarchical Fuzzy Process) And actually, effectiveness was verified according to proposed model to major port in northeast asia.

• 한국식품영양과학회지
• /
• 제34권5호
• /
• pp.573-580
• /
• 2005

수용성 식이섬유의 섭취는 혈청 콜레스테롤 저하효과가 있으며 , 그 작용기 작으로는 수용성 식이섬유의 점성으로 인한 콜레스테롤과 담즙산 흡수저해, 대장내 미생물 발효로 생성 된 단쇄지방산에 의한 콜레스테롤 합성률 변경 및 담즙산 합성증가 등으로 설명되어진다. 그러나 명확한 작용기전은 규명 되지 않았다. 본 연구에서는 간세포 핵내의 CYP7A1의 발현에 호르몬과 식이섬유의 발효로 생성된 단쇄지방산이 미치는 영향을 알아보았다. 사람의 간세포(HepG2 세포)의 배양배지에 insulin, dexamethasone 및 triiodothyronine을 각각 $1\;{\mu}M$ 투여하고 24시간 배양하였다. Semi-quantitative RT-PCR기법에 의해 CYP7A1 mRNA발현을 측정한 결과, dexamethasone에서 가장 높아 $173\%$의 증가를 나타내었고, 그 다음으로 insulin에서 $150\%$, triiodothyronine 에서 $141\%$의 증가를 나타내었다. 이처럼 transient transfection을 하지 않은 HepG2 세포에서 생리적 조절자로 알려진 insulin, dexamethasone 및 triiodothyronine이 CYP7A1의 발현을 모두 증가시킨다는 결과는 본 연구에서 처음으로 규명하며, rat gene and/or human gene 발현이 다르게 조절됨을 제안한다. 단쇄지방산에 의한 HepG2 세포에서의 CYP7A1 유전자의 발현 정도를 측정하기 위해서 actetate, propionate 및 butyrate를 각각 1 M농도로 24시간 동안 배양한 결과, 모든 단쇄지방산이 CYP7A1의 발현을 증가시켰다. Acetate와 propionate는 유사한 효과를 나타내어 대조군에 비하여 1.8배의 증가를 나타내었으며 , butyrate는 1.5배의 증가를 보였다. 이상의 결과는 수용성 식이섬유 섭취시 나타나는 콜레스테롤 저하 효과는 수용성 식이섬유의 대장 발효가 대장을 자극함으로써 내인성 호르몬의 변화를 통해서 나타나거나 대장내 발효산물인 actetate, propionate 및 butyrate 등이 흡수되어 간에서의 CYP7A1의 up-regulation에 의한 담즙산 배설증가에 따른 결과로 설명할 수 있을 것이다. 단쇄지방산의 CYP7A1 발현에 미치는 작용은 acetate와 propionate가 butyrate보다 큼을 알 수 있었다.

• Journal of Pharmaceutical Investigation
• /
• 제36권4호
• /
• pp.263-269
• /
• 2006

Deficiencies in the early ADMET(absorption, distribution, metabolism, elimination and toxicity) information on drug candidate extract a significant economic penalty on pharmaceutical firms. Microscale cell culture analogue-microscale gastrointestinal(${\mu}CCA-{\mu}GI$) device using Caco 2, L2 and HEp G2/C3A cells, which mimic metabolic process after absorption occurring in humans was used to investigate the toxicity of the model chemical, acetaminophen(AAP). The toxicity of acetaminophen determined after induction of CYP 1A1/2 in Caco 2 cells was not significant. In a coculture system, although no significant reduction in viability of HEp G2/C3A and L2 cells was found, approximately 5 fold increase in the CYP 1A1/2 activity was observed. These results appear to be related to organ-organ interaction. The oral administration of a drug requires addition of the absorption process through small intestine to the current ${\mu}CCA$ device. Therefore, a perfusion coculture system was employed for the evaluation of the absolution across the small intestine and resulting toxicity in the liver and lung. This system give comprehensive and physiologic information on oral uptake and resulting toxicity as in the body. The current ${\mu}CCA$ device can be used to demonstrate the toxic effect due to organ to organ interaction after oral administration,

• Journal of Electrical Engineering and Technology
• /
• 제13권4호
• /
• pp.1528-1538
• /
• 2018

In this paper, configuration of $1-{\phi}$ seven-level boost DC-link cascade based reversing voltage multilevel inverter (BDCLCRV MLI) is proposed for uninterrupted power supply (UPS) applications. It consists of three level boost converter, level generation unit and full bridge circuit for polarity generation. When compared with conventional boost cascaded H-bridge MLI configurations, the proposed system results in reduction of DC sources, reduced power switches and gate drive requirements. Inverter switching is accomplished by providing appropriate switching angles that is generated by any optimization switching angle techniques. Here, round modulation control (RMC) method is taken as the optimization method and switching angles are derived and the same is compared with various switching angles methods i.e., equal-phase (EP) method, and half-equal-phase (HEP) method which results in improved quality of obtained AC power with lowest total harmonic distortion (THD). Reduction in DC sources and switch count makes the system more cost effective. A simulation and prototype model of $1-{\phi}$ seven-level BDCLCRV MLI system is developed and its performance is analyzed for various operating conditions.

• 대한한의정보학회지
• /
• 제21권1호
• /
• pp.14-22
• /
• 2015

Flavonoids show diverse bioactivities, such as anti-oxidant, anti-cancer, anti-allergic, anti-inflammatory, and anti-viral. Quercetin is one of the flavonoids present in a wide range of plants, especially onions and consumed all over the world. Recently, it is known that quercetin induces mitochondrial biogenesis in vivo and in vitro. However, detail mechanism of these actions remains unknown. We investigated quercetin's effects on mitochondrial biogenesis in HepG2 cells, and determined the mechanisms involved. We found that quercetin treatment induced the expression of mitochondrial biogenesis activators, $PGC-1{\alpha}$, NRF-1, TFAM, and mitochondrial proteins, cytochorome c and complex IV (COXIV). Moreover, amount of mitochondrial DNA was also increased by quercetin. Quercetin has been known to induce heme oxygenase (HO)-1 in several types of cells. Here, we found quercetin induces HO-1, and inhibition of HO-1 or CO, which is product of HO-1, decreased quercetin-induced mitochondrial biogenesis such as induction of $PGC-1{\alpha}$, NRF-1, TFAM, cytochorome c, COXIV, and mitochondrial DNA. These findings imply that quercetin can increase mitochondrial biogenesis via HO-1/CO system. High glucose results in dysfunction of mitochondria biogenesis. In the present study, 25 mM glucose decreased mitochondrial biogenesis and this damage was restored by quercetin. Conversely, inhibition of HO-1 or CO inhibited quercetin-induced mitochondrial biogenesis rescue. These results suggest that quercetin enhances mitochondrial biogenesis via HO-1/CO system and hence, can rescue mitochondria from damage by high glucose.

• 대한한의학회지
• /
• 제19권2호
• /
• pp.244-270
• /
• 1998

This study was performed to investigate an anti-HBV activities of the aqueous extracts from 10 Korean herbal medicines in the HepG2 2.2.15 cell culture system and the results were as follows: 1. The extracts of 6 plants (Herba Artemisiae Capillaris, Radix et Rhizoma Rhei, Cortex Cinnamomi, Fructus Chebulae, Fructus Rubi and Radix Rubi) decreased, significantly and dose-dependently, the levels of extracellular HBV virion in the concentrations (10, 100, 500 and $1,000\;{\mu}g/m{\ell}$) tested. 2. However, others (Radix lsatidis, Lignum Sappan, Herba Lysimachiae and Fructus Lycii) did not show any effect either on the replication of HBV or on the levels of virion DNA in the culture media of HepG2 2.2.15 cell. 3. Among the 6 plants which showed the inhibitory potency on the production of extracellular HBV virion, Radix et Rhizoma Rhei, Cortex Cinnamomi, Fructus Chebulae, Fructus Rubi and Radix Rubi except Herba Artemisiae Capillaris also showed the inhibition of the replication of intracellular HEV DNA in the range of $100{\sim}500\;{\mu}g/m{\ell}$. Considering the above results, it is thought that 6 plants(Herba Artemisiae Capillaris, Radix et Rhizoma Rhei, Cortex Cinnamomi, Fructus Chebulae, Fructus Rubi and Radix Rubi) possess the anti-HBV activities in the HepG2 2.2.15 cell culture system. We thus suggest that these plants possess a potential as a therapeutic agent for the chronic viral hepatitis. These results might be useful as a basic data for the development of the new preventive drugs for HBV diseases.

• 대한약학회:학술대회논문집
• /
• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
• /
• pp.80.2-80.2
• /
• 2003

The nucleoside analogue, L-FMAUS was synthesized from L-FMAU which has been shown to have significant antiviral acitivity against hepatitis B virus (HBV). The anti-HBV activity and toxicity of the L-FMAUS were examined by a cell culture system using a hepatitis B virus (HBV) producing cell line, HepG2 2.2.15. L-FMAUS was assayed for the inhibition of HBV multiplication by measurement of HBV DNA and surface antigen (HBsAg) levels in the extracellular medium of HepG2 2.2.15 cells after an 8-day treatment. (omitted)

• 한국미생물생명공학회:학술대회논문집
• /
• 한국미생물생명공학회 2003년도 2003 Annual Meeting, BioExhibition and International Symposium
• /
• pp.129-131
• /
• 2003

Recombinant bioluminescent bacteria and cultured human cells were applied for toxicogenomic analysis of environmentally hazardous chemicals. Recombinant bioluminescent biosensing cells were used to detect and classify the toxicity caused by various chemicals. Classification of toxicity was realized based upon the chemicals' mode of action using DNA-, oxidative-, protein, and membrane-damage sensitive strains. As well, a simple double-layered cell culture system using Caco-2 cells and Hep G2 cells, which mimic the metabolic processes occurring in humans, such as adsorption through the small intestine and biotransformationin both the small intestine and the liver, was developed to investigate the toxicity of hazardous materials to humans. For a more in-depth analysis, a DNA microarray was used to study the transcriptional responses of Caco-2 and Hep G2 cells to benzo〔a〕pyrene.

• 전기전자학회논문지
• /
• 제21권3호
• /
• pp.320-330
• /
• 2017

Porous nanosilica (PNS) has been identified as a potential candidate for controlled drug delivery. However, unmodified PNS-based carriers exhibited an initial release of loaded bioactive agents, which may limit their potential clinical applications. In this study, the surface of PNS was functionalized with adamantylamine (ADA) via disulfide bonds (-S-S-), PNS-S-S-ADA, which was then modified with cyclodextrin (CD)-heparin (Hep) (CD-Hep), PNS-S-S-CDH, for redox triggered rhodamine B (RhB) delivery. The obtained samples were then characterized by proton nuclear magnetic resonance ($^{1}H\;NMR$), Fourier transform infrared (FTIR), and transmission electron microscope (TEM). These results showed that PNS-S-S-CDH was successfully formed with spherical shape and average diameter of $45.64{\pm}2.33nm$. In addition, RhB was relatively encapsulated in the PNS-S-S-CDH (RhB@PNS-S-S-CDH) and slowly released up to 3 days. The release of RhB, in particular, was triggered due to the cleavage of -S-S- in the presence of dithiothreitol (DTT). It might be anticipated that the modified PNS can be used as redox-responsive drug delivery system in cancer therapy.

• Archives of Pharmacal Research
• /
• 제27권9호
• /
• pp.947-953
• /
• 2004

The antioxidative and hepatoprotective potentials of two anthraquinones, alaternin (2-hydroxy-emodin) and emodin, to scavenge and/or inhibit hydroxyl radicals generated by the Fenton reaction and to protect tacrine-induced cytotoxicity in human liver derived HepG2 cells were evaluated, respectively. The inhibitory activity on hydroxyl radical generated in a cell-free chemical system (FeSO$_4$/$H_2O$$_2$) was investigated by a fluorescence spectrophotometer using a highly fluorescent probe, 2$^1$,7$^1$-dichlorofluorescein. The hydroxyl radical scavenging activity was determined by electron spin resonance spectroscopy using 5,5-dimethy-1-pyrroline-N-oxide as hydroxyl radicals trapping agents. Tacrine-induced HepG2 cell toxicity was determined by a 3-［4,5-dimethylthiazole-2yl］-2,5-diphenyltertrazolium bromide assay. Although the scavenging activity of alaternin on hydroxyl radical was similar to that of emodin in dose-dependent pat-terns, the inhibitory activity exhibited by the former on hydroxyl radical generation was stron-ger than that of the latter, with $IC_{50}$/ values of 3.05$\pm$0.26 $\mu$M and 13.29$\pm$3.20 $\mu$M, respectively. In addition, the two anthraquinones, alaternin and emodin showed their hepatoprotective activ-ities on tacrine-induced cytotoxicity, and the EC$_{50}$ values were 4.02 11M and 2.37 $\mu$M, respec-tively. Silymarin, an antihepatotoxic agent used as a positive control exhibited the EC$_{50}$ value of 2.00 $\mu$M. These results demonstrated that both alaternin and emodin had the simultaneous antioxidant and hepatoprotective activities.ies.