• Title/Summary/Keyword: $E_2$

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Antifungal Activity of Medium-Chain ($C_{6}-C_{13}$) Alkenals against, and Their Inhibitory Effect on the Plasma Membrane $H^{+}$-ATPase of Saccharomyces cerevisiae

  • Lee, Jae-Ran;Lee, Sang-Hwa;Kubo, Isao;Hong, Soon-Duck
    • Journal of Microbiology and Biotechnology
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    • v.8 no.3
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    • pp.197-202
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    • 1998
  • Aliphatic alkenals having 6 to 13 carbons were evaluated for antifungal activity against Saccharomyces cerevisiae. The activity was gradually increased with chain length, e.g., (E)-2-decenal and (E)-2-undecenal exhibited maximum potency, while (E)-2-dodecenal and (E)-2-tridecenal were completely inactive. Alkenals showed increasing inhibitory activity with chain length, as in the case of antifungal activity, towards glucose-induced medium acidification by the plasma membrane $H^+$-ATPase of S. cerevisiae. The group including (E)-2-nonenal, (E)-2-decenal, and (E)-2-undecenal exhibited maximum potency, but the potency of (E)-2-dodecenal and (E)-2-tridecenal demonstrated a sudden drop with respect to the former group. (E)-2-Nonenal revealed dose-responsive inhibition to the medium acidification and inhibited over 90% at a concentration of 1.25 mM ($175.3{\mu}g$/ml). In contrast to (E)-2-undecenal whose inhibitory efficiency increased with incubation time, inhibition by (E)-2-dodecenal was reversed with time. Of the tested alkenals, (E)-2-heptenal and (E)-2-octenal most highly inhibited ATP hydrolytic activity by the plasma membrane $H^+$ ATPase, while (E)-2-heptenal at 10 mM ($1121.8{\mu}g$/ml) showed an inhibitory efficacy of 93.2%.

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A Study on the Change and Development Strategies of E-Commerce Industry in China

  • Byoung-Goo KIM;Chunsu LEE
    • The Journal of Industrial Distribution & Business
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    • v.15 no.5
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    • pp.1-15
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    • 2024
  • Purpose: The purpose of this study is to explore the development and characteristics of e-commerce in China and analyze the current status of e-commerce platforms in China. Research design, data and methodology: To explore the development of e- commerce in China, this study collects and analyzes Chinese journals and secondary sources. It also conducts a case analysis of the success strategies of leading Chinese e-commerce companies. Results: The analysis showed that China's e-commerce is active in various forms of e-commerce, including B2B, B2C, and C2C, and that the development of e-commerce in China has been divided into three main stages. The Chinese government has been actively implementing various policies to promote the development of e-commerce. Conclusions: In this context, this paper specifically examines the development process of e- commerce in China, the current status of the Chinese e-commerce market, and the characteristics of the Chinese e-commerce market. In addition, the paper analyzes representative B2B, B2C, and C2C companies in China's e-commerce market. The results of the analysis show that Huichongwang, a B2B company, Jingdong, a B2C company, and Taobao, a C2C company, have achieved rapid growth through their core strategies and capabilities. The study also analyzed in detail the problems faced by the Chinese government and companies.

Growth Inhibition of Enteropathogenic Escherichia coli $A_2$and Escherichia coli $G_7$ by the Organic Acid Producing Bacteria (유기산 생성균에 의한 병원성 Escherichia Coli $A_2$와 Escherichia Coli $G_7$의 생육억제)

  • 백영진;배형석
    • Microbiology and Biotechnology Letters
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    • v.16 no.2
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    • pp.111-118
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    • 1988
  • The growth inhibition of enteropathogenic Escheriohia coli $A_2$and Escherichia coli G$_7$, causing the diarrhea in piglets, by the organic acid producing bacteria was studied in vitro. The metabolites of the organic acid bacteria, such as lactic acid, acetic acid inhibited the growth of E. coli $A_2$and E. coli G$_7$ in BL medium. The more the organic acid producing bacteria have ability to produce the organic acids, the higher these bacteria excelled the inhibitory efficacy against enteropathogenic E. coli. Among the strains examined, Lactobacillus casei Y and Streptococcus faecium C showed relatively strong growth inhibition against enteropathogenic E. coli.. When the organic acid producing bacteria and the enteropathogenic E. coli were incubated simultaneously in BL medium, bacteriostasis of E. coli was observed when the pH of BL culture was lowered to 5.0, and bacteriocidal effect was observed when the pH became Bess than 4.5, E. coli. $A_2$was more resistant to the organic acid bacteria than E. coli G$_7$.

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Tristetraprolin Regulates Prostate Cancer Cell Growth Through Suppression of E2F1

  • Lee, Hyun Hee;Lee, Se-Ra;Leem, Sun-Hee
    • Journal of Microbiology and Biotechnology
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    • v.24 no.2
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    • pp.287-294
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    • 2014
  • The transcription factor E2F1 is active during G1 to S transition and is involved in the cell cycle and progression. A recent study reported that increased E2F1 is associated with DNA damage and tumor development in several tissues using transgenic models. Here, we show that E2F1 expression is regulated by tristetraprolin (TTP) in prostate cancer. Overexpression of TTP decreased the stability of E2F1 mRNA and the expression level of E2F1. In contrast, inhibition of TTP using siRNA increased the E2F1 expression. E2F1 mRNA contains three AREs within the 3'UTR, and TTP destabilized a luciferase mRNA that contained the E2F1 mRNA 3'UTR. Analyses of point mutants of the E2F1 mRNA 3'UTR demonstrated that ARE2 was mostly responsible for the TTP-mediated destabilization of E2F1 mRNA. RNA EMSA revealed that TTP binds directly to the E2F1 mRNA 3'UTR of ARE2. Moreover, treatment with siRNA against TTP increased the proliferation of PC3 human prostate cancer cells. Taken together, these results demonstrate that E2F1 mRNA is a physiological target of TTP and suggests that TTP controls proliferation as well as migration and invasion through the regulation of E2F1 mRNA stability.

Effects of Taurine and $\beta$-alanine on Blood Glucose and Blood Lipid Concentrations in Streptozotocin-induced Diabetic Rats (타우린과 베타알라닌이 실험적 당뇨유발 쥐의 혈당 및 혈정지질농도에 미치는 영향)

  • 장경자
    • Journal of Nutrition and Health
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    • v.32 no.3
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    • pp.213-220
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    • 1999
  • The purpose of this study was to determine the dose effects of taurine supplementation and effects of taurine depletion in diabetic rats. Sprague-Dawley male rats were fed the purified diets and supplemented with 1, 2 or 3% taurine in drinking water for 7 weeks(E1, E2 and E3, respectively). To induce taurine depletion, rats were treated with 5% $\beta$-alanine in drinkeng water (EA). Diabetes was induced by streptozotocin injection(50mg/kg B.W) after 3 weeks. Taurine-depleted diabetic rats(EA)had significantly lower body weight compared to those of nondiabetic(CO), nontaurine-supplemented diabetic(E0) and taurine-supplemented diabetic rats(E1, E2 and E3). E0 had significantly higher food intake compared to that of CO and EA. E1, E2 and E3, however, had significantly lower food intake compared to that of E0, and E3 had significantly lower food intake compared to that of E1 and E2. E0 had significantly higher water intake compare to that of CO and EA. EI had significantly lower water intake compared to that of E0. Blood glucose concentration of E0 was significantly increased compared to that of CO and EA. E2 and E3 had significantly lower blood glucose concentration compared to E0 and E1. Also there was a dose effect in blood glucose concentration between E2 and E3. The total cholesterol and LDL-cholesterol concentrations of EA were significantly increased compared to those of other groups. Therefore, it may be suggested that taurine supplementation is necessary for diabetes in order to prevent diabetic complications such as cardiac vascular diseases.

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A Study on the Possibility of Being Successful B2B e-Marketplaces in the Early stages (우리나라 기업간 e-Marketplace의 단계별 성장가능에 관한 탐색적 연구)

  • An, Chong-Soo
    • International Commerce and Information Review
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    • v.5 no.1
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    • pp.39-59
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    • 2003
  • The purpose of this paper is to examine the possibility of whether B2B e-marketplaces continue to grow. There are numerous barriers to the growth of e-marketplace, but certain key factors can push e-marketplaces beyond these obstacles. In the stage of generating traffic, it is essential to find a vertical area to attract buyers and sellers which can generate B2B transaction through e-marketplace. Generating traffic is possible only for e-marketplaces established by those who have vertical knowledges and strong off-line relationship in the vertical areas. In the stage of concentrating traffic, more attention should be given to reach critical mass and to increase transaction through e-marketplace. Currently, there seems to be a tendency that having major buyers as members of a e-marketplace is an true factor for the successful e-marketplace. Finally, to attain the locking traffic, e-marketplace needs to have the ability to generate revenue through B2B transaction. What we have learn from this study is that having the software-technology is not a sufficient condition to successfully operate B2B e-marketplace. It is important for e-marketplace to attract major players in order to increase B2B transaction, and also to make profit by them.

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A Study on the Promotion of B2B e-Marketplace by the Strategic Use of e-Credit Guarantee System (전자신용보증 제도의 전략적 활용과 B2B e-Marketplace의 활성화)

  • Lee, Geum-Ryong;Sam, Seong-Ryeol
    • 한국디지털정책학회:학술대회논문집
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    • 2005.06a
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    • pp.145-175
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    • 2005
  • In 2001, e-Credit guarantee system was introduced by the Korea Credit Guarantee Fund(KCGF) to extends the credit guarantee services for the purchasing amount on credit in the B2B e-Marketplace. It combines both the merits of bill of exchange and credit card and eliminates the uneasiness related to the unpaid accounts due to the non-facial e-Marketplace. The purpose of this paper is to empirically analyze both the causal relationship and influences among theoretical variables by the structural equation model(SEM). e-Credit guarantee system can be a good strategy for promoting B2R e-Marketplace. The level of application of e-Credit guarantee system is attributable to both the characteristics of B2B e-Marketplace and products. The cost reduction or saving in purchasing procedures, production and stockpiling will be possible through e-Credit guarantee system. The close linkage of financial institutions with the enterprises based on e-Credit guarantee system will further promote B2B e-Marketplace in Korea.

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A Study on the Promotion of B2B e-Marketplace by the Strategic Use of e-Credit Guarantee System (전자신용보증 제도의 전략적 활용과 B2B e-Marketplace의 활성화)

  • Lee, Keum-Ryong;Shim, Sang-Ryul
    • Journal of Digital Convergence
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    • v.3 no.1
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    • pp.45-73
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    • 2005
  • In 2001, e-Credit guarantee system was introduced by the Korea Credit Guarantee Fund(KCGF) to extends the credit guarantee services for the purchasing amount on credit in the B2B e-Marketplace. It combines both the merits of bill of exchange and credit card and eliminates the uneasiness related to the unpaid accounts due to the non-facial e - Marketplace. The purpose of this paper is to empirically analyze both the causal relationship and influences among theoretical variables by the structural equation model(SEM). e-Credit guarantee system can be a good strategy for promoting B2B e-Marketplace. The level of application of e-Credit guarantee system is attributable to both the characteristics of B2B e-Marketplace and products. The cost reduction or saving in purchasing procedures, production and stockpiling will be possible through e-Credit guarantee system. The close linkage of financial institutions with the enterprises based on e-Credit guarantee system will further promote B2B e-Marketplace in Korea.

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Curcumin Induces Downregulation of E2F4 Expression and Apoptotic Cell Death in H CT116 Human Colon Cancer Cells; Involvement of Reactive Oxygen Species

  • Kim, Kyung-Chan;Lee, Chu-Hee
    • The Korean Journal of Physiology and Pharmacology
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    • v.14 no.6
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    • pp.391-397
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    • 2010
  • E2F transcription factors and their target genes have been known to play an important role in cell growth control. We found that curcumin, a polyphenolic phytochemical isolated from the plant Curcuma longa, markedly suppressed E2F4 expression in HCT116 colon cancer cells. Hydrogen peroxide was also found to decrease E2F4 protein level, indicating the involvement of reactive oxygen species (ROS) in curucmin-induced downregulation of E2F4 expression. Involvement of ROS in E2F4 downregulation in response to curcumin was confirmed by the result that pretreatment of cells with N-acetylcystein (NAC) before exposure of curcumin almost completely blocked the reduction of E2F4 expression at the protein as well as mRNA level. Anti-proliferative effect of curcumin was also suppressed by NAC which is consistent to previous reports showing curcumin-superoxide production and induction of poly (ADP-ribose) polymerase (PARP) cleavage as well as apoptosis. Expression of several genes, cyclin A, p21, and p27, which has been shown to be regulated in E2F4-dependent manner and involved in the cell cycle progression was also affected by curcumin. Moreover, decreased (cyclin A) and increased (p21 and p27) expression of these E2F4 downstream genes by curcumin was restored by pretreatment of cells with NAC and E2F4 overexpression which is induced by doxycycline. In addition, E2F4 overexpression was observed to partially ameliorate curcumin-induced growth inhibition by cell viability assay. Taken together, we found curcumin-induced ROS down-regulation of E2F4 expression and modulation of E2F4 target genes which finally lead to the apoptotic cell death in HCT116 colon cancer cells, suggesting that E2F4 appears to be a novel determinant of curcumin-induced cytotoxicity.

Identification of Polymorphisms in CYP2E1 Gene and Association Analysis among Chronic HBV Patients

  • Chun, Ji-Yong;Park, Byung-Lae;Cheong, Hyun-Sub;Kim, Jason-Y.;Park, Tae-Joon;Lee, Jin-Sol;Lee, Hyo-Suk;Kim, Yoon-Jun;Shin, Hyoung-Doo
    • Genomics & Informatics
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    • v.7 no.4
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    • pp.187-194
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    • 2009
  • Cytochrome P450 2E1 (CYP2E1) is a member of the cytochrome P450 superfamily, and it is a key enzyme responsible for the metabolic activation of many smallmolecular-weight compounds such as alcohol, which is classified as a human carcinogen. In this study, we identified 19 single nucleotide polymorphisms (SNPs) in CYP2E1 in Korean population. In these SNPs, we examined possible genetic association of CYP2E1 polymorphisms with HBV clearance and the risk of hepatocellular carcinoma (HCC). Five common polymorphic sites were selected, CYP2E1 polymorphisms at rs381-3867, rs3813870, rs2070673, rs2515641 and rs2480257, considering their allele frequencies, haplotype-tagging status and LDs for genotyping in larger-scale subjects (n=1,092). Statistical analysis demonstrated that CYP2E1 polymorphisms and haplotypes show no significant association with HBV clearance, HCC occurrence and onset age of HCC (p>0.05). Previous studies, however, have shown contradictory findings on associations of CYP2E1 polymorphisms with CYP2E1 activities and HCC risk. Comparing the contrasting results of previous researches suggest that CYP2E1 polymorphism is associated with CYP2E1 activity induced by ethanol, but is not directly associated with HCC risk. CYP2E1 variation/haploype information identified in this study will provide valuable information for future studies on CYP2E1.