• Title/Summary/Keyword: Growth activation

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Growth Kinetics of Intermetallic Compound on Sn-3.5Ag/Cu, Ni Pad Solder Joint with Isothermal Aging (등온시효에 따른 Sn-3.5Ag 솔더 접합부의 금속간 화합물 성장에 관한 연구)

  • 이인영;이창배;정승부;서창제
    • Journal of Welding and Joining
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    • v.20 no.1
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    • pp.97-102
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    • 2002
  • The growth kinetics of intermetallic compound layers formed between the eutectic Sn-3.5Ag solder and the Cu and Ni/Cu pad by solid stateisothermal aging were examined. The interfacial reaction between the eutectic Sn-3.5Ag solder and the Cu and Ni/Cu pad was investigated at 70, 120, 150, $170^{\circ}C$ for various times. The intermetallic compound layer was composed of two phase: $Cu_6Sn_5$(${\varepsilon}-phase$) adjacent to the solder and $Cu_6Sn_5$(${\varepsilon}-phase$) adjacent to the copper and on solder/Ni pad the intermetallic compound layer was $Ni_3Sn_4$. Because the values of time exponent(n) have approximately 0.5, the layer growth of the intermetallic compound was mainly controlled by volume diffusion over the temperature range studied. The apparent activation energy for layer growth of total Cu-Sn($Cu_6Sn_5 + Cu_6Sn$), $Cu_6Sn_5$, $Cu_3Sn$ and $Ni_3Sn_4$ intermetallic compound were 64.82kJ/mol, 48.53kJ/mol, 89.06kJ/mol and 71.08kJ/mol, respectively.

Paromomycin Derived from Streptomyces sp. AG-P 1441 Induces Resistance against Two Major Pathogens of Chili Pepper

  • Balaraju, Kotnala;Kim, Chang-Jin;Park, Dong-Jin;Nam, Ki-Woong;Zhang, Kecheng;Sang, Mee Kyung;Park, Kyungseok
    • Journal of Microbiology and Biotechnology
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    • v.26 no.9
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    • pp.1542-1550
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    • 2016
  • This is the first report that paromomycin, an antibiotic derived from Streptomyces sp. AG-P 1441 (AG-P 1441), controlled Phytophthora blight and soft rot diseases caused by Phytophthora capsici and Pectobacterium carotovorum, respectively, in chili pepper (Capsicum annum L.). Chili pepper plants treated with paromomycin by foliar spray or soil drenching 7 days prior to inoculation with P. capsici zoospores showed significant (p < 0.05) reduction in disease severity (%) when compared with untreated control plants. The disease severity of Phytophthora blight was recorded as 8% and 50% for foliar spray and soil drench, respectively, at 1.0 ppm of paromomycin, compared with untreated control, where disease severity was 83% and 100% by foliar spray and soil drench, respectively. A greater reduction of soft rot lesion areas per leaf disk was observed in treated plants using paromomycin (1.0 μg/ml) by infiltration or soil drench in comparison with untreated control plants. Paromomycin treatment did not negatively affect the growth of chili pepper. Furthermore, the treatment slightly promoted growth; this growth was supported by increased chlorophyll content in paromomycin-treated chili pepper plants. Additionally, paromomycin likely induced resistance as confirmed by the expression of pathogenesis-related (PR) genes: PR-1, β-1,3-glucanase, chitinase, PR-4, peroxidase, and PR-10, which enhanced plant defense against P. capsici in chili pepper. This finding indicates that AG-P 1441 plays a role in pathogen resistance upon the activation of defense genes, by secretion of the plant resistance elicitor, paromomycin.

${\alpha}$-Mangostin Reduced ER Stress-mediated Tumor Growth through Autophagy Activation

  • Kim, Sung-Jin;Hong, Eun-Hye;Lee, Bo-Ra;Park, Moon-Ho;Kim, Ji-Won;Pyun, A-Rim;Kim, Yeon-Jeong;Chang, Sun-Young;Chin, Young-Won;Ko, Hyun-Jeong
    • IMMUNE NETWORK
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    • v.12 no.6
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    • pp.253-260
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    • 2012
  • ${\alpha}$-Mangostin is a xanthon derivative contained in the fruit hull of mangosteen (Garcinia mangostana L.), and the administration of ${\alpha}$-Mangostin inhibited the growth of transplanted colon cancer, Her/CT26 cells which expressed Her-2/neu as tumor antigen. Although ${\alpha}$-Mangostin was reported to have inhibitory activity against sarco/endoplasmic reticulum $Ca^{2+}$ ATPase like thapsigargin, it showed different activity for autophagy regulation. In the current study, we found that ${\alpha}$-Mangostin induced autophagy activation in mouse intestinal epithelial cells, as GFP-LC3 transgenic mice were orally administered with 20 mg/kg of ${\alpha}$-Mangostin daily for three days. However, the activation of autophagy by ${\alpha}$-Mangostin did not significantly increase OVA-specific T cell proliferation. As we assessed ER stress by using XBP-1 reporter system and phosphorylation of $eIF2{\alpha}$, thapsigargin-induced ER stress was significantly reduced by ${\alpha}$-Mangostin. However, coadministration of thapsigargin with ${\alpha}$-Mangostin completely blocked the antitumor activity of ${\alpha}$-Mangostin, suggesting ER stress with autophagy blockade accelerated tumor growth in mouse colon cancer model. Thus the antitumor activity of ${\alpha}$-Mangostin can be ascribable to the autophagy activation rather than ER stress induction.

Short hairpin RNA targeting of fibroblast activation protein inhibits tumor growth and improves the tumor microenvironment in a mouse model

  • Cai, Fan;Li, Zhiyong;Wang, Chunting;Xian, Shuang;Xu, Guangchao;Peng, Feng;Wei, Yuquan;Lu, You
    • BMB Reports
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    • v.46 no.5
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    • pp.252-257
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    • 2013
  • Fibroblast activation protein (FAP) is a specific serine protease expressed in tumor stroma proven to be a stimulatory factor in the progression of some cancers. The purpose of this study was to investigate the effects of FAP knockdown on tumor growth and the tumor microenvironment. Mice bearing 4T1 subcutaneous tumors were treated with liposome-shRNA complexes targeting FAP. Tumor volumes and weights were monitored, and FAP, collagen, microvessel density (MVD), and apoptosis were measured. Our studies showed that shRNA targeting of FAP in murine breast cancer reduces FAP expression, inhibits tumor growth, promotes collagen accumulation (38%), and suppresses angiogenesis (71.7%), as well as promoting apoptosis (by threefold). We suggest that FAP plays a role in tumor growth and in altering the tumor microenvironment. Targeting FAP may therefore represent a supplementary therapy for breast cancer.

Effect of Clitocybin A on the Proliferation of Dermal Papilla Cells (Clitocybin A의 모유두 세포증식 효능)

  • Kang, Jung-Il;Kim, Min-Kyoung;Yoo, Eun-Sook;Yoo, Ick-Dong;Kang, Hee-Kyoung
    • Korean Journal of Pharmacognosy
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    • v.45 no.4
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    • pp.288-293
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    • 2014
  • The present study was conducted to evaluate the hair growth-promoting effect of Clitocybin A from mushroom Clitocybe aurantiaca with dermal papilla cells (DPCs), which play important roles in the regulation of hair cycle. Clitocybin A significantly increased the proliferation of immortalized rat vibrissa DPCs. Flow cytometry analysis revealed that Clitocybin A promoted cell-cycle progression through G0/G1 to S phase in immortalized rat vibrissa DPCs. In addition, Clitocybin A increased the level of cell cycle proteins such as cyclin D1, phospho-pRB, and phospho-CDK2. To elucidate the molecular mechanisms of Clitocybin A on the proliferation of DPCs, we examined the activation of wnt/${\beta}$-catenin signaling which is known to regulate hair follicle development, differentiation and hair growth. Clitocybin A activated wnt/${\beta}$-catenin signaling via the increase of phospho(ser552)-${\beta}$-catenin, phospho(ser675)-${\beta}$-catenin and phospho(ser9)-$GSK3{\beta}$. Furthermore, Clitocybin A markedly increased the activation of extracellular signal-regulated kinase (ERK). These results suggest that the Clitocybin A may induce hair growth by proliferation of DPCs via cell-cycle progression as well as the activation of Wnt/${\beta}$-catenin signaling and ERK pathway.

Stimulation of Cell Growth by Erythropoietin in RAW264.7 Cells: Association with AP-1 Activation

  • Seong Seu-Run;Lee Jae-Woong;Lee Yong-Kyoung;Kim Tae-Il;Son Dong-Ju;Moon Dong-Cheol;Yun Young-Won;Yoon Do-Young;Hong Jin-Tae
    • Archives of Pharmacal Research
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    • v.29 no.3
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    • pp.218-223
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    • 2006
  • Erythropoietin (EPO), a hematopoietic factor, is required for normal erythrocyte developments, but it has been demonstrated to have many other functions, and its receptor is localized in other tissues. In the present study, we investigated whether EPO can promote other cell proliferation and possible molecular mechanisms. EPO restored the inhibition of the RAW264.7 and PC12 cell growth by fetal bovine serum (FBS) withdrawal in a dose dependent manner, but not that of other cell types tested. The restoring effect of EPO was completed when the RAW264.7 cells were cultured in the medium containing as low as 3% of FBS, and 10 U/mL EPO could replace FBS. The restoring effect of EPO in the RAW264.7 cells was associated with the increased of c-Fos and c-Jun expression as well as AP-1 activation. These data demonstrate that EPO can stimulate RAW264. 7 cell as well as PC12 cell growth even when the cells were cultured without FBS or in the presence of small amounts of FBS in the medium, and this stimulating effect is associated with the activation of AP-1 transcription factor.

Growth and $\beta$-Glucosidase Activity of Bifidobacterium

  • CHOI, YUN-JUNG;CHUL-JAI KIM;SO-YOUNG PARK;YOUNG-TAE KO;HOO-KIL JEONG;GEUN-EOG JI
    • Journal of Microbiology and Biotechnology
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    • v.6 no.4
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    • pp.255-259
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    • 1996
  • $\beta$-Glucosidase was known to be involved in the mutagenic activation of $\beta$-glucosides. The level of $\beta$-glucosidase in the feces of adults was 2.7 times higher than that of infants. There was no difference in the percentage of $\beta$-glucosidase positive strains among Bifidobacterium isolates between adults and infants, corresponding to 90 and 92$%$, respectively. However, the strains from adults showed 1.9 times higher enzyme activity than those from infants when grown in Brain Heart Infusion medium. $\beta$-Glucosidase negative strains could not ferment $\beta$-glucosidase substrates, such as cellobiose, salicin, naringin, esculin and arbutin. Presence of $\beta$-glucosidase in Bifidobacterium did not alter the degree of growth in reconstituted skim milk. The $\beta$-glucosidase level was much lower in milk and vegetable medium, although cells grew above $10^8$cfu/ml, than in BHI medium. This study suggests that metabolic activation of the $\beta$-glucosides by Bifidobacterium $\beta$-glucosidase varies significantly depending on types of growth medium.

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Insulin activates EGFR by stimulating its interaction with IGF-1R in low-EGFR-expressing TNBC cells

  • Shin, Miyoung;Yang, Eun Gyeong;Song, Hyun Kyu;Jeon, Hyesung
    • BMB Reports
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    • v.48 no.6
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    • pp.342-347
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    • 2015
  • The expression of epidermal growth factor receptor (EGFR) is an important diagnostic marker for triple-negative breast cancer (TNBC) cells, which lack three hormonal receptors: estrogen and progesterone receptors as well as epidermal growth factor receptor 2. EGFR transactivation can cause drug resistance in many cancers including TNBC, but the mechanism underlying this phenomenon is poorly defined. Here, we demonstrate that insulin treatment induces EGFR activation by stimulating the interaction of EGFR with insulin-like growth factor receptor 1 (IGF-1R) in the MDA-MB-436 TNBC cell line. These cells express low levels of EGFR, while exhibiting high levels of IGF-1R expression and phosphorylation. Low-EGFRexpressing MDA-MB-436 cells show high sensitivity to insulinstimulated cell growth. Therefore, unexpectedly, insulin stimulation induced EGFR transactivation by regulating its interaction with IGF-1R in low-EGFR-expressing TNBC cells. [BMB Reports 2015; 48(6): 342-347]

Effects of Euphorbiae lathyridis Semen on cell apoptosis in HT-29 human colon cancer cells (속수자가 HT-29 대장암세포의 활성 및 세포사멸에 미치는 영향)

  • Lee, Jae-Hyun;Jung, Sun-Ju;Park, Yong-Ki
    • The Korea Journal of Herbology
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    • v.22 no.2
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    • pp.65-72
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    • 2007
  • Objectives : In this study, we investigate that Euphorbiae lathyridis Semen extract contributes to growth inhibitory effect and anti-cancer activity on the HT-29 human colon cancer cells. Methods : Euphorbiae lathyridis Semen was extracted from the Semen of the plant using 80% Methanol. The Euphorbiae lathyridis Semen extract was treated to different concentrations for 24 hr, 4Shr or 72hr. Growth inhibitory effect was analyzed by measuring FACS study and MTT assay. Cell apoptosis was confirmed by surveying caspases cascades activation using Westem blot. Results : Exposure to Euphorbiae lathyridis Semen extract (0.4mg/ml) results in an inhibitory effect on cell growth in HT-29 cells. Growth inhibition by Euphorbiae lathyridis Semen extract in HT-29 cells was related with the inhibition of proliferation and induction of apoptosis. The Euphorbiae lathyridis Semen extract induces DNA fragmentation in HT-29 cells. Furthermore, Euphorbiae lathyridis Semen extract induces cell apoptosis through the activation of caspases-3, caspase-9 and PARP cleavage. Conclusion : Euphorbiae lathyridis Semen extract induces apoptosis in human colon cancer cells, therefore, we suggest that Euphorbiae lathyridis Semen extract can be used as a novel class of anti-cancer drugs.

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