• 제목/요약/키워드: Role transition

검색결과 671건 처리시간 0.028초

Inhibitory Effects of Phylligenin on the Proliferation of Cultured Rat Neural Progenitor Cells

  • Lee, Sung-Hoon;Go, Hyo-Sang;Choi, Chang-Soon;Cheong, Jae-Hoon;Han, Sun-Young;Bae, Ki-Hwan;Ko, Kwang-Ho;Park, Seung-Hwa
    • Biomolecules & Therapeutics
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    • 제18권1호
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    • pp.48-55
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    • 2010
  • Neural progenitor cells (NPCs) differentiate into astrocytes, neurons and oligodendrocytes, which is controlled by various factors in brain. Recent evidences suggest that small molecules modulating the proliferation and differentiation of NPCs may have therapeutic value as well as the potential use as chemical probes. Phylligenin is a lignan with anti-inflammatory activity that is isolated from the fruits of Forsythia koreana. We investigated effects of phylligenin on proliferation and differentiation of NPCs. Treatment of phylligenin decreased the number of proliferating NPCs in culture without effects on the differentiation and survival of neural cells such as neurons and astrocytes. To examine the mechanism of the decreased NPCs number, we performed cell cycle analysis. Proliferation of NPCs was decreased via G1-S transition block by phylligenin treatment, and it was mediated by the increase of p21 level. However, phylligenin did not induce apoptosis of NPCs as determined by TUNEL assay and PARP cleavage. We also found that viability of glioma cell lines such as C6 and U87MG glioma cells, but not that of primary neuron and astrocyte, was inhibited by phylligenin. These results suggest that phylligenin selectively inhibits proliferation of rapidly growing cells such as neural stem cells and glioma cells. Given that the possible role of brain tumor stem cells in the pathology of brain cancers, the inhibitory effects of phylligenin might be useful in the development of new therapeutic agents against brain cancers.

동적 교통량-밀도 관계의 특성 분석과 교통류 모형으로의 응용 (Analysis of Characteristics of the Dynamic Flow-Density Relation and its Application to Traffic Flow Models)

  • 김영호;이시복
    • 대한교통학회지
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    • 제22권3호
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    • pp.179-201
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    • 2004
  • 지능형 교통체계(intelligent transport systems)의 구축이 점차 널리 확대됨에 따라 교통류의 실시간 모형화(online traffic flow modeling)의 중요성이 증대되고 있다. 교통량-밀도 관계는 주어진 교통량, 밀도 상황에서 교통류의 행태를 나타낼 뿐만 아니라 거시 교통류 모형의 결과에 많은 영향을 미친다. 현재까지 교통량-밀도관계에 관한 대부분의 연구는 그 관계식을 규명하는데 그치고 있다. 상류부와 하류부의 교통 상태에 따른 교통량-밀도관계의 시간적 변화는 교통류의 모형화에 반드시 고려되어야 할 특성이지만, 현재까지 그에 대한 연구가 폭넓게 이루어지지 않고 있는 실정이다. 본 논문에서는 한 지점에서의 교통량-밀도관계가 시간의 흐름에 따라 분석되었고 states diagram으로 표현되었다. 동적 교통량-밀도관계 (dynamic flow-density relation)는 states diagram으로부터 fuzzy-logic을 이용하여 유추되었고, 거시 교통류모형을 실시간으로 응용할 수 있는 기초를 제공하였다. 동적 교통량-밀도관계를 거시 교통류 모형에 이용함으로써 교통류의 실시간 모형화 과정에서 발생하는 모수추정 (parameter calibration) 문제를 완화하였다.

폴리비닐 부티랄에 붙힌 지르코늄 알콕시드 졸을 사용한 전기방사에서 지르코니아 나노섬유 제조와 광발광 (Photoluminescence and Fabrication of Zirconia Nanofibers from Electrospinning an Alkoxide Sol Templated on a Polyvinyl Butyral)

  • 고태경;한규석;임태균;오성규;한상환
    • 한국세라믹학회지
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    • 제47권4호
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    • pp.343-352
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    • 2010
  • A zirconia gel/polymer hybrid nanofiber was produced in a nonwoven fabric mode by electrospinning a sol derived from hydrolysis of zirconium butoxide with a polyvinyl butyral. Results indicated that the hydroxyl groups on the vinyl alcohol units in the backbone of the polymer were involved in the hydrolysis as well as grafting the hydrolyzed zirconium butoxide. In addition, use of acetic acid as a catalyst resulted in further hydrolysis and condensation in the sol, which led to the growth of -Zr-O-Zr- networks among the polymer chains. These networks gradually transformed into a crystalline zirconia structure upon heating. The as-spun fiber was smooth but partially wrinkled on the surface. The average fiber diameter was $690{\pm}110\;nm$. The fiber exhibited a strong but broad blue photoluminescence with its maximum intensity at a wavelength of ~410 nm at room temperature. When the fiber was heat-treated at $400^{\circ}C$, the fiber diameter shrunk to $250{\pm}60\;nm$. Nanocrystals which belonged to a tetragonal zirconia phase and were ~5 nm in size appeared. A strong white photoluminescence was observed in this fiber. This suggests that oxygen or carbon defects associated with the formation of the nanocrystals play a role in generating the photoluminescence. Further heating to $800^{\circ}C$ resulted in a monoclinic phase beginning to form In the heat-treated fibers, coloring occurred but varied depending on the heating temperature. Crystallization, coloring, and phase transition to the monoclinic structure influenced the photoluminescence. At $600^{\circ}C$, the fiber appeared to be fully crystallized to a tetragonal zirconia phase.

How to Explain the Contradiction of microRNA 200c Expression and Survival in Solid Tumors?: a Meta-analysis

  • Wang, Hui-Yu;Shen, Jie;Jiang, Chun-Ping;Liu, Bao-Rui
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권8호
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    • pp.3687-3690
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    • 2014
  • MicroRNA 200c is a microRNA 200 family member that plays an important role in regulation of the epithelial-to-mesenchymal transition (EMT). The prognostic value of microRNA 200c in solid tumors remains controversial because of inconsistent data. Here, we report a meta-analysis of the association of microRNA 200c expression and survival in patients with solid tumors. Pubmed was searched up to November 2013 for studies investigating microRNA 200c expression and overall survival (OS) in solid tumors. Hazard ratios (HRs) with 95% confidence intervals (CIs) for OS were extracted from each study. Pooled HR and CIs were calculated using the Mantel-Haenszel fixed-effects models. A total of five studies evaluating colorectal cancer, gastric cancer, ovarian cancer, pancreatic cancer and endometrial cancer were included in the analysis. Data were divided into tissue microRNA 200c expression group and serum microRNA 200c expression group. The combined HRs [95%CIs] estimated for OS were 0.62 [0.42-0.91] and 2.16 [1.32-3.52] respectively. Low expression of microRNA 200c in tumor tissue and high expression of microRNA 200c in serum are associated with worse survival in solid tumors. Further study is needed to elucidate this contradiction.

Obesity and Obese-related Chronic Low-grade Inflammation in Promotion of Colorectal Cancer Development

  • Pietrzyk, Lukasz;Torres, Anna;Maciejewski, Ryszard;Torres, Kamil
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권10호
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    • pp.4161-4168
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    • 2015
  • Colorectal cancer (CRC) is a worldwide health problem, being the third most commonly detected cancer in males and the second in females. Rising CRC incidence trends are mainly regarded as a part of the rapid 'Westernization' of life-style and are associated with calorically excessive high-fat/low-fibre diet, consumption of refined products, lack of physical activity, and obesity. Most recent epidemiological and clinical investigations have consistently evidenced a significant relationship between obesity-driven inflammation in particular steps of colorectal cancer development, including initiation, promotion, progression, and metastasis. Inflammation in obesity occurs by several mechanisms. Roles of imbalanced metabolism (MetS), distinct immune cells, cytokines, and other immune mediators have been suggested in the inflammatory processes. Critical mechanisms are accounted to proinflammatory cytokines (e.g. IL-1, IL-6, IL-8) and tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$). These molecules are secreted by macrophages and are considered as major agents in the transition between acute and chronic inflammation and inflammation-related CRC. The second factor promoting the CRC development in obese individuals is altered adipokine concentrations (leptin and adiponectin). The role of leptin and adiponectin in cancer cell proliferation, invasion, and metastasis is attributable to the activation of several signal transduction pathways (JAK/STAT, mitogen-activated protein kinase (MAPK), phosphatidylinositol 3 kinase (PI3K), mTOR, and 5'AMPK signaling pathways) and multiple dysregulation (COX-2 downregulation, mRNA expression).

한국 사회에서 영화의 지성화 과정에 관한 연구 : 1988~2007년까지의 인쇄매체에 나타난 영화담론을 중심으로 (Intellectualization of Film genre in Korea: the case of Film discourse From 1988 to 2007)

  • 김정환
    • 한국콘텐츠학회논문지
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    • 제13권2호
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    • pp.88-99
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    • 2013
  • 이 연구는 1987년 영화의 자율화 정책 이후 인쇄 매체에서 생산된 담론 분석을 통하여 영화의 사회적 위상 변화를 살펴보고자 한다. 이를 위해 피에르 부르디외의 문화사회학 이론을 원용하여 영화의 사회적인 위상의 변화를 전문적인 영역과 대중적인 영역으로 구분하여 분석하였다. 분석 시기는 1988년부터 2007년까지 전문적인 영역은 '영화학 관련 석 박사 논문'과 대표적인 영화학 학술지 "영화연구"(1989~2007)를 통해서 알아보았고, 대중적인 영역은 '영화관련 단행본'을 중심으로 알아보았다. 논문의 결과에 따르면, 영화를 분석하는 틀이 전문화 다양화 되어 영화 장 내부의 상징자본이 축적되고 있음을 알 수 있었고, 영화의 지성화 과정에서 영화를 학문적으로 접근하는 논리와 산업과 정책적인 측면으로 접근하는 논리 간의 역학관계가 중요한 역할을 수행하였다.

Expression and Significance of Twist and E-cadherin in Ovarian Cancer Tissues

  • Wang, Wen-Shuang;Yu, Shou-Li;Yang, Xing-Sheng;Chang, Shu-De;Hou, Jian-Qing
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권2호
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    • pp.669-672
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    • 2013
  • Objective: To investigate the expression of Twist and E-cadherin in ovarian cancer tissues as well as the role of epithelial-mesenchymal transformation (EMT) in ovarian cancer metastasis. Method: The expressions of Twist and E-cadherin in 54 cases of ovarian cancer and paracancerous tissues were detected by Western blottin g and reverse transcriptase polymerase chain reaction. We used RNA interference to silence Twist expression in human ovarian cancer cell line, and detected E-cadherin expression using Western blotting. Results: There was an increase in the relative abundance of Twist proteins and a decrease in E-cadherin in ovarian cancer compared with normal ovary tissues (P < 0.05). The expression levels of Twist and E-cadherin mRNA were $1.49{\pm}0.53$ and $0.82{\pm}0.24$ in ovarian cancer, and $1.14{\pm}0.38$ and $1.08{\pm}0.19$ in paracancerous tissues, respectively. The difference between the indicators in ovarian cancer and in paracancerous tissues was statistically significant (P < 0.05). When the Twist expression was silenced in an ovarian cancer cell line, the expression of the E-cadherin protein increased (P<0.05). Conclusion: The expression of Twist is upregulated, whereas that of E-cadherin is downregulated in ovarian cancer. EMT, mediated by Twist, may be correlated with ovarian cancer metastasis.

C. I. Reactive Black 5로 염색된 면직물의 알칼리발염에 있어 2단계 고착조건 및 요소의 영향 (The Effects of Two-step Fixation and Urea on the Alkali Discharge Printing of Cotton Fabrics Dyed with C. I. Reactive Black 5)

  • 정화진;박건용
    • 한국염색가공학회지
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    • 제11권1호
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    • pp.16-24
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    • 1999
  • The effects of two-step fixation of steaming and baking on the dischargeability of cotton fabrics dyed with C.I. Reactive Black 5(Bl-5) were investigated when the concentrations of $K_2CO_3$ and benzaldehyde sodium bisulfite(BASB) were increased over 120/kg. Remarkably increased dischargeability resulted from baking for 3 min or more at 160t after steaming for 8 min or more at $102^\circ{C}$, but 120g/kg or more amounts of $K_2CO_3$ and BASB(50%) had little influence on dischargeability. Therefore the discharge mechanism can be suggested that covalent bonds between cellulose and Bl-5 undergo $S_N2$ attack by hydroxide ion formed by the reaction of $K_2CO_3$ and water in steaming at $102^\circ{C}$ first and then, through transition states they are cleavaged in baking at 160t to yield hydrolyzed Bl-S and compounds of BASB and Bl-5 isolated from fiber, which are undyeable and removed by washing. The effect of urea, one of the hydrotrope agents, on discharge printing was also studied. The result which dischargeability was greatly improved by increasing the steaming time from 8 min to 15 min at $102^\circ{C}$ or by increasing the amount of urea obviously shows that water in steaming and urea in print paste play an important role in discharge printing. And as an increase of the baking time from 5 min to 7 min at $160^\circ{C}$ makes it possible to improve dischargeability, it is once more confirmed that high temperature of about 160t is exactly required to discharge the dyed Bl-5. The colored discharge printing demands a more amount of urea because urea contributes to the putting color fixation as well as the discharge reaction.

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Alteration of Striatal Tetrahydrobiopterin in Iron-Induced Unilateral Model of Parkinson's Disease

  • Aryal, Bijay;Lee, Jin-Koo;Kim, Hak Rim;Kim, Hyung-Gun
    • The Korean Journal of Physiology and Pharmacology
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    • 제18권2호
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    • pp.129-134
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    • 2014
  • It has been suggested that transition metal ions such as iron can produce an oxidative injuries to nigrostriatal dopaminergic neurons, like Parkinson's disease (PD) and subsequent compensative increase of tetrahydrobiopterin ($BH_4$) during the disease progression induces the aggravation of dopaminergic neurodegeneration in striatum. It had been established that the direct administration of $BH_4$ into neuron would induce the neuronal toxicity in vitro. To elucidate a role of $BH_4$ in pathogenesis in the PD in vivo, we assessed the changes of dopamine (DA) and $BH_4$ at striatum in unilateral intranigral iron infused PD rat model. The ipsistriatal DA and $BH_4$ levels were significantly increased at 0.5 to 1 d and were continually depleting during 2 to 7 d after intranigral iron infusion. The turnover rate of $BH_4$ was higher than that of DA in early phase. However, the expression level of GTP-cyclohydrolase I mRNA in striatum was steadily increased after iron administration. These results suggest that the accumulation of intranigral iron leads to generation of oxidative stress which damage to dopaminergic neurons and causes increased release of $BH_4$ in the dopaminergic neuron. The degenerating dopaminergic neurons decrease the synthesis and release of both $BH_4$ and DA in vivo that are relevance to the progression of PD. Based on these data, we propose that the increase of $BH_4$ can deteriorate the disease progression in early phase of PD, and the inhibition of $BH_4$ increase could be a strategy for PD treatment.

1990년대 이후 현대 남성복에 나타난 패션 경향에 관한 연구 (Study on the Fashion Trend of Contemporary Men's Wear Since 1990)

  • 김혜정
    • 패션비즈니스
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    • 제14권5호
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    • pp.78-92
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    • 2010
  • The culture phenomenon, which the desire of self expression is noticeable and the diversity of gender identity is widely accepted, simply makes a difference in the lifestyle of one human being rather than the dichotomous classification of male and female. Now, the delicate and aesthetic sensitivity classified as the feminine characteristics is no longer the exclusive property of female and this refers to substituting it as a social gender from the concept of biological sex. This phenomenon has influenced on the male culture and is creating various codes according to the cultural gender extended from the gender as a social role. Also, the transition into the western lifestyle has extended the aesthetic emotion to accommodate new codes from the diversification and globalization of lifestyle. The mansumer power, which does not care too much about the money for the emotionally attached items, has enabled various fashion styles. After analyzing the diversified clothing behavior conducted by these people in connection with the social phenomenon, First, this shows the phenomenon of emotional value pursuit that finds pleasure over the clothing as the item of augmented reality is added to the concept of play, in which the real space referred to as garment and virtual space of playing the rock, paper and scissors game meet together within the augmented reality. Second, the convergence concept has enabled the coordination of new style by obscuring the area of design concept and this refers to the changes in design from the development of new items and transformation into double-style details. Third, the divergence that intensively provides specific use/convenience and specialized value shows a change in the fashion market from the phenomenon that admits various gene rations of culture and specifically, takes differently about the recognition of middle-aged males. Fourth, the variety seeking tendency receives attention as the value of future design together with the phenomenon of discriminative value pursuit. In the male fashion, it is linked to the collaboration with the design area and this tells that the fashion with the narcissistic cross-dressing and motto of neutral gender without being sided to male/female is rising.