• Journal of Korean Society of Transportation
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• v.20 no.5
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• pp.113-130
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• 2002

In this paper, we developed DNL(Dynamic Network Loading) model based on Moving cell theory to analyze the dynamic characteristics of traffic flow in congested network. In this paper vehicles entered into link at same interval would construct one cell, and the cells moved according to Cell following rule. In the past researches relating to DNL model a continuous single link is separated into two sections such as running section and queuing section to describe physical queue so that various dynamic states generated in real link are only simplified by running and queuing state. However, the approach has some difficulties in simulating various dynamic flow characteristics. To overcome these problems, we present Moving cell theory which is developed by combining Car following theory and Lagrangian method mainly using for the analysis of air pollutants dispersion. In Moving cell theory platoons are represented by cells and each cell is processed by Cell following theory. This type of simulation model is firstly presented by Cremer et al(1999). However they did not develop merging and diverging model because their model was applied to basic freeway section. Moreover they set the number of vehicles which can be included in one cell in one interval so this formulation cant apply to signalized intersection in urban network. To solve these difficulties we develop new approach using Moving cell theory and simulate traffic flow dynamics continuously by movement and state transition of the cells. The developed model are played on simple network including merging and diverging section and it shows improved abilities to describe flow dynamics comparing past DNL models.

• Journal of Korean Society of Transportation
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• v.20 no.5
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• pp.33-43
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• 2002

Travel choice behavior is affected by real-time traffic information. Recently, in urban area, real-time traffic information is provided by several instruments such as transportation broadcasting, internet PC network and variable message sign, etc. Furthermore, it has been increasing for urban travelers to use real-time traffic information provided by several instruments. The purpose of this study is to analyze the effects of advanced traveler information on urban worker's travel choice behavior. Among several Advanced Traveler Information System(ATIS) employed in urban area. This study focuses on examining the effects of transportation broadcasting on urban worker's travel choice behavior. This study attempts to examine traveler's mode change behavior in the pre-trip stage and traveler's route change behavior in the on-route stage. For this study, the survey data collected from Daegu City in 2000 is used. For empirical analysis, several nested logit models are estimated, and among them, the best models are reported in this paper. Furthermore, based on the empirical models estimated for this research, important findings and their policy implications are discussed.

• Journal of Life Science
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• v.16 no.4
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• pp.589-597
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• 2006

Genistein, a natural isoflavonoid phytoestrogen, is a strong inhibitor of protein tyrosine kinase and DNA topoisomerase activities. There are several studies documenting molecular alterations leading to cell cycle arrest and induction of apoptosis by genistein as a chemopreventive agent in a variety of cancer cell lines; however, its mechanism of action and its molecular targets on human bladder carcinoma and leukemic cells remain unclear. In the present study, we have addressed the mechanism of action by which genistein suppressed the proliferation of T24 bladder carcinoma and U937 leukemic cells. Genistein significantly inhibited the cell growth and induced morphological changes, and induced the G2/M arrest of the cell cycle in both T24 and U937 cells with a relatively stronger cytotoxicity in U937. The G2/M arrest in T24 cells was associated with the inhibition of cyclin A, cyclin B1 and Cdc25C protein expression without alteration of tumor suppressor p53 and cyclin-dependent kinase (Cdk) inhibitor p21(WAF1/CIP1). However, the inhibitory effects of genistein on the cell growth of U937 cells were connected with a marked inhibition of cyclin B1 and an induction of Cdk inhibitor p21 proteins by p53-independent manner. These data suggest that genistein may exert a strong anticancer effect and additional studies will be needed to evaluate the different mechanisms between T24 and U937 cells.

• Journal of Life Science
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• v.16 no.7 s.80
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• pp.1235-1242
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• 2006

Sulforaphane, an isothiocyanate derived from hydrolysis of glucoraphanin in broccoli and other cruciferous vegetables, was shown to induce phase II detoxification enzymes and inhibit chemically induced mammary tumors in rodents. Recently, sulforaphane is known to induce cell cycle arrest and apoptosis in human canter cells, however its molecular mechanisms are poorly understood. In tile present study, we demonstrated that sulforaphane acted to inhibit proliferation and induce morphological changes of human hepatocarcinoma HepG2 cells. Treatment of HepG2 cells with $10{\mu}M\;or\;15{\mu}M$ sulforaphane resulted in significant G2/M cell cycle arrest as determined by DNA flow cytometry. Moreover, $20{\mu}M$ sulforaphane significantly induced the population of sub-G1 cells suggesting that sulforaphane induced apoptosis. This anti-proliferative effect of sulforaphane was accompanied by a marked inhibition of ryclin A, cyclin 31 and Cdc2 protein. However, the levels of tumor suppressor p53 and Cdk inhibitor p21 mRNA and protein expression were significantly increased by sulforaphane treatment in a concentration-dependent manner. Although further studies are needed, the present work suggests that sulforaphane may be a potential rhemoprevetiveichemotherapeucc agent for the treatment of human cancer cells.

• Microbiology and Biotechnology Letters
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• v.41 no.4
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• pp.425-432
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• 2013

Typha orientalis, also known as bulrush or cattail, is a perennial herbaceous plant found in freshwater wetlands and has been widely used in constructed wetlands for wastewater treatment. Recent data has revealed that SH21B, a mixture composed of seven herbs including T. orientalis, exhibited an anti-adipogenic activity by the inhibition of the expression of adipogenic regulators. However, the anti-cancer effect of T. orientalis and its molecular mechanisms remain unclear. In this study, we evaluated the anti-cancer effect and its mechanism in the methanol extract of T. orientalis (METO) on human colon carcinoma HT29 cells. It was found that METO treatment showed cytotoxic activity in a dose-dependent manner, and induced G2/M cell cycle arrest and apoptosis in HT29 cells. The induction of G2/M arrest by METO was associated with the up-regulation of phospho-Cdc2 (Tyr15), an inactive form of Cdc2 and the down-regulation of Cdc25c phosphatase. METO also induced tumor suppressor p53 and cyclin-dependent kinase inhibitor p21 (WAF1/CIP1) expression. In addition, METO-induced apoptosis was characterized by the proteolytic activation of caspase-3, degradation of poly ADP ribose polymerase (PARP), and up-regulation of death receptor FAS and pro-apoptotic Bax expression. Collectively, these results indicate that the cell cycle inhibition and apoptosis induction of METO in HT29 cells allows for the possibility of its use in anti-cancer therapies.

• Journal of Life Science
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• v.15 no.2 s.69
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• pp.169-175
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• 2005

Resveratrol (3,4',5-trihydroxy-trans-stilbene), a phytoalexin found in grape skins, peanuts, and red wine, has been reported to have a wide range of biological and pharmacological properties. $Amyloid-\beta$ deposition and senile plaque-associated astrocytes are common neuropathological features of Alzheimer's disease. In this study, we have explored the effects of resveratrol on $amyloid-\beta-peptide-mediated$ cytotoxicity in vitro and modulation of cell growth-regulatory gene products in astroglioma C6 cells to elucidate its possible mechanism for anti-cytotoxicity. Exposure of C6 cells to $Amyloid-\beta$ resulted in dose-dependent growth inhibition and morphological changes of C6 cells, which were recovered by pre-treatment with resveratrol. The anti-proliferative effect of $amyloid-\beta$ was associated with the induction of tumor suppressor p53 and cyclin-dependent kinase (Cdk) inhibitor p21 (WAF1/CIP1) expression assessed by RT-PCR and Western blot analysis in time-dependent manner in C6 cells. In addition, the pro-apoptotic Bax expression was also up-regulated in $amyloid-\beta-treated$ C6 cells without alteration of anti-apoptotic Bcl-2 and $Bcl-X_L$ expression. However, pre-treatment of resveratrol significantly inhibited $amyloid-\beta-induced$ p53, p21 and Bax levels, suggesting that the modulation of p53, p21 and Bax levels could be one of the possible pathways by which resveratrol functions as anti-cytotoxic agent. Our results demonstrate that resveratrol may enhance the protection against $amyloid-\beta-induced$ cytotoxicity by promoting the survival of glial cells.

• Tuberculosis and Respiratory Diseases
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• v.41 no.4
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• pp.339-353
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• 1994

Background : The p53 gene codes for a DNA-binding nuclear phosphoprotein that appears to inhibit the progression of cells from the G1 to the S phase of the cell cycle. Mutations of the p53 gene are common in a wide variety of human cancers, including lung cancer. In lung cancers, point mutations of the p53 gene have been found in all histological types including approximately 45% of resected NSCLC and even more frequently in SCLC specimens. Mutant forms of the p53 protein have transforming activity and interfere with the cell-cycle regulatory function of the wild-type protein. The majority of p53 gene mutations produce proteins with altered conformation and prolonged half life; these mutant proteins accumulate in the cell nucleus and can be detected by immunohistochemical staining. But protein overexpression has been reported in the absence of mutation. p53 protein overexpression or gene mutation is reported poor prognostic factor in breast cancer, but in lung cancer, its prognostic significance is controversial. Method : We investigated the p53 abnormalities by nucleotide sequencing, polymerase chain reaction-single strand conformation polymorphism(PCR-SSCP), and immunohistochemical staining. We correlated these results with each other and survival in 75 patients with NSCLC resected with curative intent. Overexpression of the p53 protein was studied immunohistochemically in archival paraffin- embedded tumor samples using the D07(Novocastra, U.K.) antibody. Overexpression of p53 protein was defined by the nuclear staining of greater than 25% immunopositive cells in tumors. Detection of p53 gene mutation was done by PCR-SSCP and nucleotide sequencing from the exon 5-9 of p53 gene. Result: 1) Of the 75 patients, 36%(27/75) showed p53 overexpression by immunohistochemical stain. There was no survival difference between positive and negative p53 immunostaining(overall median survival of 26 months, disease free median survival of 13 months in both groups). 2) By PCR-SSCP, 27.6%(16/58) of the patients showed mobility shift. There was no significant difference in survival according to mobility shift(overall median survival of 27 in patients without mobility shift vs 20 months in patients with mobility shift, disease free median survival of 8 months vs 10 months respectively). 3) Nucleotide sequence was analysed from 29 patients, and 34.5%(10/29) had mutant p53 sequence. Patients with the presence of gene mutations showed tendency to shortened survival compared with the patients with no mutation(overall median survival of 22 vs 27 months, disease free median survival of 10 vs 20 months), but there was no statistical significance. 4) The sensitivity and specificity of immunostain based on PCR-SSCP was 67.0%, 74.0%, and that of the PCR-SSCP based on the nucleotide sequencing was 91.8%, 96.2% respectively. The concordance rate between the immunostain and PCR-SSCP was 62.5%, and the rate between the PCR-SSCP and nucleotide sequencing was 95.3%. Conclusion : In terms of detection of p53 gene mutation, PCR-SSCP was superior to immunostaining. p53 gene abnormalities either overexpression or mutation were not a significant prognostic factor in NSCLC patients resected with curative intent. However, patients with the mutated p53 gene showed the trends of early relapse.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.10
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• pp.1552-1559
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• 2013

Rubus coreanus Miquel (RCM) has been used as one of the Korean traditional medicines for prostate health. In addition, recent studies have reported that RCM reduced chronic inflammatory diseases such as cancer, and rheumatoid arthritis. Therefore, in this study, we investigated the effects of unripe and ripe RCM on inflammationrelated gene expressions in LPS-stimulated mouse peritoneal macrophages. Mice were fed with 2% unripe RCM (U2), 10% unripe RCM (U10), 2% ripe RCM (R2), and 10% ripe RCM (R10) for 8 weeks. Peritoneal macrophages were isolated and stimulated with LPS then proinflammatory mediators (TNF-${\alpha}$, IL-$1{\beta}$, and IL-6), and prostaglandin E2 ($PGE_2$) productions were assessed. Moreover, gene expression profiles were analyzed by cDNA microarray method. Unripe and ripe RCM significantly reduced TNF-${\alpha}$ production but only unripe RCM decreased IL-$1{\beta}$ and IL-6 production. RCM intake significantly reduced inflammatory-related gene expressions such as arachidonate 5-lipoxygenase, interleukin 11, and nitric oxide synthase 2. Furthermore, unripe and ripe RCM significantly decreased ceruloplasmin, tissue plasminogen activator, thrombospondin 1, and vascular endothelial growth factor A expression which modulates symptoms of chronic inflammatory diseases. RCM intake also significantly increased hypoxia inducible factor 3, alpha which is the negative regulators of hypoxia-inducible gene expression. Furthermore, only unripe RCM reduced chemokine (C-C motif) ligand 8, chemokine (C-X-C motif) ligand 14, and phospholipase A2 expression. In this study, we showed that RCM had anti-inflammatory effects by suppression of pro-inflammatory mediator expressions and may reduce chronic inflammatory disease progress through regulation of gene expressions. These findings suggest that RCM might be used as a potential functional material to reduce chronic inflammatory responses.

• Journal of Korean Society of Transportation
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• v.20 no.7
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• pp.155-166
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• 2002

Since 1990s. there has been an increasing number of traffic accidents at intersection. which requires more urgent measures to insure safety on intersection. This study set out to analyze the road conditions, traffic conditions and traffic operation conditions on signalized intersection. to identify the elements that would impose obstructions in safety, and to develop a traffic accident prediction model to evaluate the safety of an intersection using the cop relation between the elements and an accident. In addition, the focus was made on suggesting appropriate traffic safety policies by dealing with the danger elements in advance and on enhancing the safety on the intersection in developing a traffic accident prediction model fir a signalized intersection. The data for the study was collected at an intersection located in Wonju city from January to December 2001. It consisted of the number of accidents, the road conditions, the traffic conditions, and the traffic operation conditions at the intersection. The collected data was first statistically analyzed and then the results identified the elements that had close correlations with accidents. They included the area pattern, the use of land, the bus stopping activities, the parking and stopping activities on the road, the total volume, the turning volume, the number of lanes, the width of the road, the intersection area, the cycle, the sight distance, and the turning radius. These elements were used in the second correlation analysis. The significant level was 95% or higher in all of them. There were few correlations between independent variables. The variables that affected the accident rate were the number of lanes, the turning radius, the sight distance and the cycle, which were used to develop a traffic accident prediction model formula considering their distribution. The model formula was compared with a general linear regression model in accuracy. In addition, the statistics of domestic accidents were investigated to analyze the distribution of the accidents and to classify intersections according to the risk level. Finally, the results were applied to the Spearman-rank correlation coefficient to see if the model was appropriate. As a result, the coefficient of determination was highly significant with the value of 0.985 and the ranks among the intersections according to the risk level were appropriate too. The actual number of accidents and the predicted ones were compared in terms of the risk level and they were about the same in the risk level for 80% of the intersections.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.1
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• pp.75-84
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• 2008

Colored potatoes are an excellent source of dietary polyphenols including anthocyanins. Generally, anthocyanins from fruits and vegetables exhibit anti-carcinogenesis and anti-cancer properties in vitro test. This experiment was conducted to know the effects of colored potato extracts contained anthocyanins on antimutagenic activity and anticancer activity to six human cancer cell lines containing LNCaP (androgen-dependent) prostate cancer cells. Extracts of three colored potatoes ('Hongyoung', 'Jayoung' and 'Jasim') and the white potato ('Superior') cultivars were used in this study. The extracts of three colored potatoes inhibited the mutagenicities induced by direct mutagen such as 4-nitro-quinoline-1-oxide (4-NQO) and another indirect mutagens of bezo(a)pyrene (BaP). Also, the extracts of 'Hoyoung' and 'Jayoung' showed higher antimutagenic activity than 'Jasim' and 'Superior' against to direct or indirect mutagen on both strains of TA98 and TA100. The activity of growth-inhibitory of extract of four potato cultivars were screened by SRB (sulphorhodamine B) method on diverse human cancer cells representing different types of cancers. Among the extract of four potato cultivars, the extract of 'Jasim' showed moderate inhibition on proliferation of LNCaP, ACHN and MOLT-4F cells and did not inhibit the proliferation of other cancer cells. On the other hand, extract of 'Superior' did not inhibit the proliferation of any tested cancer cell lines. However, the extracts of 'Hongyoung and Jayoung' inhibited the proliferation of cancer cells with $GI_{50}$ values ranging from 2.5 to $30\;{\mu}g/mL$. On the basis of the $GI_{50}$ values, it is clear that LNCaP cells were more sensitive to extracts of colored potato cultivars than other cancer cells. The extract of 'Jayoung' at $30\;{\mu}g/mL$ were more active and inhibited cell proliferation, and induced apoptosis in LNCaP cells. This result revealed that the extracts of colored potatoes are expected to be good candidate for development into source of antimutagenic and anticancer agent.