• Journal of Korea Water Resources Association
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• v.42 no.2
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• pp.161-168
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• 2009

The purpose of this study is to evaluate the variation of probability flood according to the flow regulation by multi-purpose dams (Soyang and Chungju) in the Han-river basin, Korea. SWAT-K (Soil and Water Assessment Tool-Korea) was used in order to generate regulated and unregulated daily streamflows upstream of Paldang dam. Simulated flow regulated by the Soyang and Chungju dams was calibrated by comparison with the observed inflow data at Paldang reservoir. Generally the ratio of flood flows to daily streamflows is known to decrease with drainage area in a watershed. Regulated and unregulated flood flows were obtained from the relationship between flood flows and daily streamflows. Extreme Type-I distribution was applied for flood frequency analysis and L-moment method was used for parameter estimation. This is a novel approach capable of understanding the variation in flood frequency with dam operation for the relatively large watershed scale, and this will helps improve the applicability of daily stream flow data for use in flood control as well as in water utilization.

• Biotechnology and Bioprocess Engineering:BBE
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• v.7 no.5
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• pp.237-251
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• 2002

The recent progress on metabolic systems engineering was reviewed based on our recent research results in terms of (1) metabolic signal flow diagram approach, (2) metabolic flux analysis (MFA) in particular with intracellular isotopomer distribution using NMR and/or GC-MS, (3) synthesis and optimization of metabolic flux distribution (MFD), (4) modification of MFD by gene manipulation and by controlling culture environment, (5) metabolic control analysis (MCA), (6) design of metabolic regulation structure, and (7) identification of unknown pathways with isotope tracing by NMR. The main characteristics of metabolic engineering is to treat metabolism as a network or entirety instead of individual reactions. The applications were made for poly-3-hydroxybutyrate (PHB) production using Ralstonia eutropha and recombinant Escherichia coli, lactate production by recombinant Saccharomyces cerevisiae, pyruvate production by vitamin auxotrophic yeast Toluropsis glabrata, lysine production using Corynebacterium glutamicum, and energetic analysis of photosynthesic microorganisms such as Cyanobateria. The characteristics of each approach were reviewed with their applications. The approach based on isotope labeling experiments gives reliable and quantitative results for metabolic flux analysis. It should be recognized that the next stage should be toward the investigation of metabolic flux analysis with gene and protein expressions to uncover the metabolic regulation in relation to genetic modification and/ or the change in the culture condition.

• The Journal of Korean Medicine
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• v.20 no.2
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• pp.88-97
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• 1999

To characterize the effects of Gilgyung-Tang(GGT) on cellular proliferation and viability of normal lung fibroblast cells, we examined the cell cycle progression and cell cycle-related gene expression in T3891 using a flow cytometry and a quantitative RT-PCR analysis. 1. The significant surpression effect of cellular proliferations of GGT was observed in proportion to a certain concentration and time. 2. GGT was identified to induce apoptotic death of damaged cells by treatment with a DNA-damage agent and etoposide, while it stimulated the recovery of cellular viability of normal cells. 3 The significant reductions of mRNA expression of PCAN, c-Fos treated by GGT were observed. 4. The significant inductions of mRNA expression of p53, CDKN1. Gadd45 treated by GGT were observed. 5. The apoptosis caused by the reduction of Bcl-2 genes was significant and the Bax genes were increased. but the amount of Fas genes were not changed. These results strongly suggest that GGT triggers arrest of the cell cycle at G1 phase, and thus causes an inhibition of cellular proliferation of human normal lung cells through the transcriptional up-regulation of cell cycle inhibitory genes and down-regulation of induction of cell cycle stimulating genes respectably.

• Journal of Electrical Engineering and Technology
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• v.12 no.6
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• pp.2208-2218
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• 2017

To resolve overload in a distribution system, a distribution system operator (DSO) often performs a load transfer using normally open tie points and switches in the distribution line. During this process, the distribution system is momentarily operated in closed-loop operation. A closed-loop current in the distribution system can cause a power failure due to excess breaking current in the circuit breakers and reclosers. Therefore, it is necessary to calculate the closed-loop current exactly. However, if there are a large number of distributed generation (DG) systems in the distribution system, such as energy storage systems (ESS), they might obstruct the closed-loop operation based on bidirectional power flow. For quick and precise operation of a closed-loop system, the ESS has to regulate the power generation while satisfying closed-loop operation in the worst cases. We propose a strategy for balanced power regulation of an ESS. Simulations were carried out using PSCAD/EMTDC, and the results were compared with calculation results.

• Herbal Formula Science
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• v.25 no.2
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• pp.145-154
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• 2017

Objectives : Bufalin is one of the bioactive component of 'Sum Su (蟾酥)', which is obtained from the skin and parotid venom gland of toad. Bufalin has been known to possess the inhibitory effects on cell proliferation and inducing apoptosis in various cancer cells. The tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) has concerned, because it can selectively induce apoptotic cell death in many types of malignant cells, while it is relatively non-toxic to normal cells. Here, we investigated whether bufalin can trigger TRAIL-induced apoptotic cell death in EJ human bladder cancer cells. Methods : Effects on the cell viability and apoptotic activity were quantified using MTT assay and flow cytometry analysis, respectively. To investigate the morphological change of nucleus, DAPI staining was performed. Protein expressions were measured by immunoblotting. Results : A combined treatment with bufalin (10 nM) and TRAIL (50 ng/ml) significantly promoted TRAIL-mediated growth inhibition and apoptosis in EJ cells. The apoptotic effects were associated with the up-regulation of death receptor proteins, and the down-regulation of cFLIP and XIAP. Moreover, our data showed that bufalin and TRAIL combination activated caspases and subsequently increased degradation of poly(ADP-ribose) polymerase. Conclusions : Taken altogether, the nontoxic doses of bufalin sensitized TRAIL-mediated apoptosis in EJ cells. Therefore, bufalin might be an effective therapeutic strategy for the safe treatment of TRAIL-resistant bladder cancers.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.16
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• pp.6627-6632
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• 2014

Purpose: The present study concerns molecular mechanisms involved in induction of apoptosis by a fungal taxol extracted from the fungus Cladosporium oxysporum in T47D human breast cancer cells. Materials and Methods: Apoptosis-induced by the fungal taxol was assessed by MTT assay, nuclear staining, DNA fragmentation, flow cytometry and pro- as well as anti-apoptotic protein expression by Western blotting. Results: Our results showed inhibition of T47D cell proliferation with an $IC_{50}$ value of $2.5{\mu}M/ml$ after 24 h incubation. It was suggested that the extract may exert its anti-proliferative effect on human breast cancer cell line by suppressing growth, arresting through the cell cycle, increase in DNA fragmentation as well as down-regulation of the expression of NF-${\kappa}B$, Bcl-2 and Bcl-XL and up-regulation of pro-apoptotic proteins like Bax, cyt-C and caspase-3. Conclusions: We propose that the fungal taxol contributes to growth inhibition in the human breast cancer cell through apoptosis induction via a mitochondrial mediated pathway, with possible potential as an anticancer therapeutic agent.

• Journal of Microbiology and Biotechnology
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• v.25 no.3
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• pp.418-422
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• 2015

In the course of screening for novel cell cycle inhibitors and apoptotic inducers, CR389, elucidated as 5-(1H-benzoimidazol-2-yl)-1H-pyridin-2-one, was generated as a new hit compound. Flow cytometric analysis and western blots of PA-1 cells treated with $60{\mu}M$ CR389 revealed an appreciable cell cycle arrest at the G2/M phase through direct inhibition of the CDK1 complex. In addition, activation of p53 via phosphorylation at Ser15 and subsequent up-regulation of p21^CIP1 showed that CR389 also induces p53-dependent-p21^CIP1-mediated cell cycle arrest. Furthermore, apoptotic induction in $60{\mu}M$ CR389-treated PA-1 cells is associated with the release of cytochrome c from mitochondria through up-regulation of the proapoptotic Bax protein, which results in the activation of procaspase-9 and -3, and the cleavage of poly(ADP-ribose) polymerase (PARP). Accordingly, CR389 seems to have multiple mechanisms of antiproliferative activity through p53-mediated pathways against human ovarian cancer cells. Therefore, we conclude that CR389 is a candidate therapeutic agent for the treatment of human ovarian cancer via the activation of p53.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.18
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• pp.8313-8319
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• 2016

We have recently shown that thymoquinone (TQ) has a potent cytotoxic effect and induces apoptosis via caspase-3 activation with down-regulation of XIAP in mouse neuroblastoma (Neuro-2a) cells. Interestingly, our results showed that TQ was significantly more cytotoxic towards Neuro-2a cells when compared with primary normal neuronal cells. In this study, the effects of TQ on cell-cycle regulation and the mechanisms that contribute to this effect were investigated using Neuro-2a cells. Cell-cycle analysis performed by flow cytometry revealed cell-cycle arrest at G2/M phase and a significant increase in the accumulation of TQ-treated cells at sub-G1 phase, indicating induction of apoptosis by the compound. Moreover, TQ increased the expression of p53, p21 mRNA and protein levels, whereas it decreased the protein expression of PCNA, cyclin B1 and Cdc2 in a dose-dependent manner. Our finding suggests that TQ could suppress cell growth and cell survival via arresting the cell-cycle in the G2/M phase and inducing apoptosis of neuroblastoma cells.

• Journal of Environmental Science International
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• v.25 no.1
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• pp.155-161
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• 2016

In this study, field experiment, odor simulator, and dispersion modeling were used to evaluate the odor impact from J sewage sludge treatment facility. The height and flow rate of exhaust stack at this facility were 22.3 m and $100Nm^3/min$. The mean odor concentrations of the wet scrubber inlet and exhaust stack were $267{\pm}160$ and $93{\pm}44OU/m^3$, respectively. The odor removal efficiency of wet scrubber showed 65%. The odor simulator is used for the regulated standard calculation of the exhaust pipe(stack). Resulting odor emission rate(OER) by odor simulator was $2.4{\times}10^6(24,000OU/m^3)$. The forecasting result by Screen3 modeling showed that odor exhaust concentration up to $30,000OU/m^3$ was't exceeded maximum allowable emission level on site boundary($15OU/m^3$).

• Journal of the Korean Society for Precision Engineering
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• v.29 no.6
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• pp.626-631
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• 2012

In this study, fatigue life of the motor block bracket units for KTX-Sancheon trains was assessed. Design evaluation for railway structures was performed based on the UIC 566 regulation, and test and evaluation of fatigue life in welded parts was performed in accordance with standard ERRI B 12/RP17 and ERRI B 12/RP60. The actual vehicle dynamic stress testing was executed in KTX-Sancheon service line with the service operating speed. The dynamic stress was measured with commercial data acquisition system (MGC plus). The cumulative damage was evaluated by applying standard BS 7608 - Class F and cycle counting was used rain-flow counting method. As a result, the motor block bracket units for KTX-Sancheon trains was designed to fit the regulation and the safety of fatigue life for 30 years, assuming that KTX-Sancheon trains travels 600,000km annually, were confirmed under current operating conditions.