• Title/Summary/Keyword: Adhesion properties

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Arsenic Trioxide Induces Apoptosis and Incapacitates Proliferation and Invasive Properties of U87MG Glioblastoma Cells through a Possible NF-κB-Mediated Mechanism

  • Ghaffari, Seyed H.;Yousefi, Meysam;Dizaji, Majid Zaki;Momeny, Majid;Bashash, Davood;Zekri, Ali;Alimoghaddam, Kamran;Ghavamzadeh, Ardeshir
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.3
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    • pp.1553-1564
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    • 2016
  • Identification of novel therapeutics in glioblastoma remains crucial due to the devastating and infiltrative capacity of this malignancy. The current study was aimed to appraise effect of arsenic trioxide (ATO) in U87MG cells. The results demonstrated that ATO induced apoptosis and impeded proliferation of U87MG cells in a dose-dependent manner and also inhibited classical NF-${\kappa}B$ signaling pathway. ATO further upregulated expression of Bax as an important proapoptotic target of NF-${\kappa}B$ and also inhibited mRNA expression of survivin, c-Myc and hTERT and suppressed telomerase activity. Moreover, ATO significantly increased adhesion of U87MG cells and also diminished transcription of NF-${\kappa}B$ down-stream targets involved in cell migration and invasion, including cathepsin B, uPA, MMP-2, MMP-9 and MMP-14 and suppressed proteolytic activity of cathepsin B, MMP-2 and MMP-9, demonstrating a possible mechanism of ATO effect on a well-known signaling in glioblastoma dissemination. Taken together, here we suggest that ATO inhibits survival and invasion of U87MG cells possibly through NF-${\kappa}B$-mediated inhibition of survivin and telomerase activity and NF-${\kappa}B$-dependent suppression of cathepsin B, MMP-2 and MMP-9.

Changes in quality characteristics of raw ginseng(Panax ginseng C.A. Meyer) pudding during storage (수삼 푸딩의 저장중 품질특성 변화)

  • Kim, Young-Kyoung;Kwon, Ki-Hyun;Kim, Byeong-Sam;Kim, Jong-Hoon;Cha, Hwan-Soo
    • Korean journal of food and cookery science
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    • v.29 no.6
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    • pp.761-768
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    • 2013
  • Healthy ginseng pudding was made with different doses of two gelling agents and stored at $37^{\circ}C$ for eight weeks. And then quality characteristics and palatability were measured. Sweetness and pH level increased in newly made ginseng puddings but decreased during storage. Acid taste decreased but increased during storage in A (pectin 0.2%+agar 0.6%). But it increased but subsequently decreased in B (agar 0.8%). Acidity in C (agar 1%) remained unchanged until six weeks but slightly increased at 8 weeks of storage. Texture increased in all specimens but subsequently decreased. Chromaticity value of L decreased in all specimens before increasing while the values of a and b increased and subsequently decreased. In texture examination, hardness and adhesion were higher in C (agar 1%) and lower in A (pectin 0.2%+agar 0.6%). There were no differences in elasticity among three specimens. Cohesion was higher in C (agar 1%) while it showed a similar level in A (pectin 0.2%+agar 0.6%) and B(agar 0.8%). Stickiness and chewiness were higher in C(agar 1%) but lower in A(Pectin 0.2%+agar 0.6%), compared with C(agar 1%) specimen. In sensory test, overall palatability was higher in A (Pectin 0.2%+agar 0.6%). In conclusion, ginseng pudding with 0.6% agar and 0.2% pectin exhibited better quality. And ginseng pudding has potential to be developed as healthy dessert considering ample physiological and functional properties.

Study on the Brazing Characteristics of LTCC/Kovar (LTCC/Kovar 간의 Brazing 특성 연구)

  • Lee, W.S.;Cho, H.M.;Lim, W.;Yoo, C.S.;Lee, Y.S.;Kang, N.K.
    • Proceedings of the International Microelectronics And Packaging Society Conference
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    • 2000.11a
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    • pp.57-57
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    • 2000
  • Brazing characteristics of the LTCC(Low Temperature Co-fired Ceramics)/ Kovar(Fe-Ni-Co alloy) was investigated. Kovar is one of the typical material for the lid of MCM and packages. In case of alumina package, Brazing process is done by higher temperature profile than 800 $^{\circ}C$ and Ag-Cu alloy. But, LTCC has sintering temperature near 850 $^{\circ}C$. So, it is difficult to use the same process as alumina brazing. The adhesion strength of the brazed part is affected by brazing alloy and metallization properties between conductor pattern and LTCC material. We investigated brazing characteristics of the LTCC/Kovar using various brazing alloys(Ag-Cu, Au-Sn) and process conditions. And, we examined the influence of the glass contents in conductor on the brazing characteristics of the LTCC/Kovar.

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EFFECT OF ROASTED BARLEY TEA ON THE ADHESIVE PROPERTIES ON SALIVA-COATED HYDROXYAPATITE BEADS OF CARIOGENIC MUTANS STREPTOCOCCI (보리차(Hordeum vulgare var, hexastichon)가 수산화인회석에 대한 우식유발성 세균의 부착에 미치는 영향)

  • Kim, Young-Jae;Kim, Chong-Chul;Kim, Kack-Kyun
    • Journal of the korean academy of Pediatric Dentistry
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    • v.29 no.4
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    • pp.618-624
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    • 2002
  • Effect of the roasted barley tea in commercial markets on the adherence to the saliva-coated hydroxyapatite(HA) beads and the cell surface hydrophobicity of Streptococcus mutans and Streptococcus sobrinus as cariogenic microorganism was examined in vitro. Adherence activity and hydrophobicity in bacteria tested in all the barley tea samples decreased and the values were different according to the type of tea and the type of treatment. The inhibition of bacterial adsorption to HA beads suggest that barley tea active molecules as catechins and melanoidins may adsorb to a host surface, preventing the tooth receptor from interacting with any bacterial adhesions. The obtained results showed that the barley tea may inhibit bacterial adherence, the first step of the pathogenesis of dental caries in which these microorganism are involved.

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Preparation of Cellulose Diacetate/Ramie Fiber Biocomposites by Melt Processing (용융가공법을 이용한 셀룰로오스 디아세테이트/라미섬유 천연복합체의 제조)

  • Lee Sang Hwan;Lee Sang Yool;Nam Jae Do;Lee Youngkwan
    • Polymer(Korea)
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    • v.30 no.1
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    • pp.70-74
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    • 2006
  • Plasticized cellulose diacetate(CDA) was prepared by homogenizing cellulose diacetate(CDA), triacetin(TA) and epoxidized soybean oil (ESO) in a high-speed mixer, then the CDA mixture was mixed with ramie fiber to produce a green composite material. In DMA analysis, the glass transition temperature of plasticized CDA and the composite was observed at $85\;^{\circ}C\;and\;140\;^{\circ}C$, respectively. A composite reinforced with alkali treated ramie fiber exhibited significantly higher mechanical properties, such as $15\;^{\circ}C$ increase in tensile strength as well as $41\;^{\circ}C$ increase in Young's modulus when compared with commercial polypropylene. In the SEM image analysis, much enhanced adhesion between plasticized CDA and alkali treated ramie fiber (AIRa) was observed.

Improvement of Polishing Characteristics Using with and without Oxidant ($H_2O_2$) of Ti/FiN Layers (산화제($H_2O_2$)의 첨가 유무에 따른 Ti/TiN막의 CMP 연마 특성)

  • Lee, Kyoung-Jin;Seo, Yong-Jin;Park, Chang-Jun;Kim, Gi-Uk;Park, Sung-Woo;Kim, Sang-Yong;Lee, Woo-Sun
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.07a
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    • pp.88-91
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    • 2003
  • Tungsten is widely used as a plug for the multi-level interconnection structures. However, due to the poor adhesive properties of tungsten (W) on $SiO_2$ layer, the Ti/TiN barrier layer is usually deposited onto $SiO_2$ for increasing adhesion ability with W film. Generally, for the W-CMP (chemical mechanical polishing) process, the passivation layer on the tungsten surface during CMP plays an important role. In this paper, the effect of oxidants controlling the polishing selectivity of W/Ti/TiN layer were investigated. The alumina ($Al_2O_3$) abrasive containing slurry with $H_2O_2$ as the oxidizer, was studied. As our preliminary experimental results, very low removal rates were observed for the case of no-oxidant slurry. This low removal rate is only due to the mechanical abrasive force. However, for Ti and TiN with $H_2O_2$ oxidizer, different removal rate was observed. The removal mechanism of Ti during CMP is mainly due to mechanical abrasive, whereas for TiN, it is due to the formation of metastable soluble peroxide complex.

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Tribological Characteristics of TiC, TiN and TiC/TiN Coatings (TiC, TiN과 TiC/TiN 코팅의 트라이볼로지 특성)

  • Jeon, Chan Yeal
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.3
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    • pp.1253-1258
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    • 2014
  • The tribological properties of TiC, TiN and TiC/TiN coatings on steels prepared by the cathodic-arc (CA) ion plating technique were investigated. Experiments were carried out on a tribo-test machine using a Falex journal V block system. The friction and wear characteristics of the coatings were determined by varying the applied load and sliding speed. The TiC, TiN and TiC/TiN coatings markedly increased the tribological characteristics of the surface. As far as a single layer coating was concerned, TiN goes better results than TiC. However, the TiC/TiN multilayer coating performed better than either single layer coating. The major factor in the improved performance of the multilayer coating was the role of TiC in improving the adhesion between the external TiN layer and the substrate steel.

Effect of Mg Content and Target Temperature on Corrosion and Adhesion Properties of Zn-Mg Coated steels (Mg 조성 및 타겟 온도 변화에 따른 Zn-Mg 도금강의 내식성 및 밀착성에 관한 연구)

  • Song, Myeon-Gyu;Ra, Jeong-Hyeon;Lee, Sang-Yul
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2017.05a
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    • pp.88-88
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    • 2017
  • Zn코팅은 우수한 내식성과 경제성을 바탕으로 자동차나 건축자재 등 산업의 전반적인 분야에서 광범위하게 사용되고 있다. 하지만 최근 한정된 Zn의 매장량으로 인한 원자제의 가격상승과 습식 도금과정의 환경오염 물질 배출 문제가 기존 Zn 코팅의 약점으로 지적되고 있다. 따라서 새로운 원소의 첨가로 인한 Zn의 사용량 감소나 친환경적인 공정방법을 적용하는 연구가 대두되고 있다. 최근의 연구 결과에 따르면 Zn-Mg 합금이 다른 Zn계 합금에 비해 내식성이 우수하며, 이와 같은 우수한 내식성은 $Mg_2Zn_{11}$, $MgZn_2$와 같은 Mg-Zn 이원계의 합금상에 의한 것으로 알려져 있다. 따라서 본 연구에서는 친환경적인 비대칭 마그네트론 스퍼터 공정을 활용하여 다양한 공정조건 하에서 Zn-Mg 박막을 합성하여 최적의 공정 조건을 도출하고자 하였다. Zn-Mg 박막 합성 시 Mg타겟의 조성은 3~10 wt.%로 변화하였으며 Zn-Mg 합금 타겟의 온도를 제어하여 박막의 Mg 조성과 타겟 온도가 Zn-Mg 도금강의 내식성 및 밀착성에 미치는 영향을 평가하였다. 합성된 Zn-Mg 박막은 FE-SEM, EDS, XRD를 사용하여 미세조직, 두께, Mg 조성, 합금상 등을 분석하였으며, 염수분무시험 및 0T 굽힘 시험을 활용하여 Zn-Mg 박막의 내식성 및 내식성을 비교 분석하였다. FE-SE및 EDS분석 결과 Zn-Mg 박막의 Mg 조성은 합금 타겟의 조성이 증가함에 따라 증가하였으며, Mg 함량이 증가할수록 미세구조가 치밀하게 변화하였다. 또한 Zn-Mg 박막 합성 중 타겟의 온도가 상승할수록 박막의 치밀도는 감소하였다. XRD분석 결과 박막을 이루는 주요 합금상은 Zn상과 $Mg_2Zn_{11}$상이며 본 연구에서는 증착 조건에 따른 합금상의 큰 변화는 보이지 않았다. 염수분무실험 및 밀착성 평가 결과 박막의 미세조직이 치밀할수록 Zn-Mg 도금강의 내식성은 향상되었으나, 밀착성은 오히려 감소하는 경향을 나타내었다. 이러한 결과는 Zn-Mg 박막이 치밀한 미세구조일수록 부식환경에서의 강판에 대한 보호 효과는 증가하는 반면, 변형 시 박막의 파괴로 인한 박리 현상이 가속되기 때문으로 판단된다.

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Study on the Peel off Style Low Viscosity Epoxy and Separation Media for a Moving Historic Sites (유구 이전 전용 저점도형 에폭시와 박리제에 관한 연구)

  • Han, Won-Sik;Hong, Tae-Kee;Park, Gi-Jung;Lim, Sung-Jin;Wi, Koang-Chul
    • Journal of Conservation Science
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    • v.24
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    • pp.37-42
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    • 2008
  • Stability of the moving historic sites have something to do with the degree of easiness of work as well as physical property of polymer product. These agents should be able to use without the effect of outer environments like water or low temperature and must have stability during progress of working the peel off Urethane pre-product from Epoxy surface. So, we synthesized low viscosity epoxy resin and hardener with best physical quality and separation media for the moving of historical sites. These products have very good tension strength, adhesion strength, low viscosity and various physical properties that the users want. Particularly, separation media products have good separation of Urethane pre-products surface and Epoxy final product surface.

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Research on the development of the properties of PLA composites for automotive interior parts (자동차 내장재 적용을 위한 PLA 복합재료의 물성개선에 관한 연구)

  • Jung, Jae-Won;Kim, Seong-Ho;Kim, Si-Hwan;Park, Jong-Kyoo;Lee, Woo-Il
    • Composites Research
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    • v.24 no.3
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    • pp.1-5
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    • 2011
  • Since the environmental problems and new stricter regulations are forcing the industries to introduce more ecological materials for their products, biodegradable materials have attracted increasing attention. Among these materials, Polylactic acid(PLA) is a promising candidate for its modulus, strength, chemical resistance. However, PLA could not be used for automobile industries for its low heat resistance and impact strength. In this study natural fibers were (jute fiber was) introduced as reinforcements in order to improve heat resistance and impact strength of PLA. Especially for improving the adhesion between PLA and jute, various surface treatments were tried. With each treatment, we verified that the impact strength of composite was improved. With annealing treatment, we found a remarkable increase of heat resistance of PLA composite.