• Title/Summary/Keyword: Adhesion control

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Technology Trend of surface Wettability Control Using Layer-by-Layer Assembly Technique (다층박막법을 이용한 표면 젖음성 제어 기술 동향)

  • Sung, Chunghyun
    • Journal of Adhesion and Interface
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    • v.18 no.4
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    • pp.171-178
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    • 2017
  • Recently, layer-by-layer (LbL) assembly has emerged as a promising fabrication technique in controlling surface wetting properties. LbL assembly technique is eco-friendly versatile technique to control the hierarchical structure and surface properties in nano- and micro-scale by employing a variety of materials (e.g., polymers, surfactants, nanoparticles, etc.). This article reviews recent progress in controlling the surface wetting using LbL technique. In particular, technical trends and research findings on fabrication and the applications of superhydrophobic, superhydrophilc, and superoleophobic/superhydrophilic LbL surfaces are extensively explained. Additionally, basic principles and fabrication methods in emerging areas such as omniphobic, self-healing, intelligent and responsive LbL surfaces are discussed.

Antimetastatic effect of several crude drugs with antitumor activity on B16-Fo and A549 cells( II ) (항암활성 수종생약의 B16-Fo와 A549 암세포에 대한 항전이 효과( II ))

  • Kim, Sung Hoon;Ryu, Shi-Yong
    • The Journal of Korean Medicine
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    • v.17 no.1 s.31
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    • pp.132-145
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    • 1996
  • Ethyl ether fractions of Ferula Resina(EFR) and Lithospermi Radix(ELR) and hexane fraction of Salviae miltiorrhizae Radix(HSR) exerted an inhibitory effect on cell adhesion of A549 to extracelluar matrix most effectively in vitro cell adhesion assay. Thus, with above fractions for the evaluation of antitumor activity, T/C% was monitored in ICR bearing S-180 and for antimetastatic effect, pulmonary colonization assay, weight of organs, changes of WBC and platelet were studied. In pulmonary colonization assay incidence rate to control was 73 % 42 %, 14 % in ELR, HSR and EFR-treated groups repsectively. Gain of lung weight was significantly inhibited in all groups while spleen weight was significantly reduced only in SMR group, but no changes in kidney and liver as compared with control. Number of platelet was significantly increased in all groups to normal range as compared with thrombocytopenic contol. WBC was significantly reduced only in LR group. These results suggest that ethyl ether fraction of Ferula Resina has more effective antimetastatic activity.

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Surface Hydrolysis of Fibrous Poly(${\epsilon}$-caprolactone) Scaffolds for Enhanced Osteoblast Adhesion and Proliferation

  • Park, Jeong-Soo;Kim, Jung-Man;Lee, Sung-Jun;Lee, Se-Geun;Jeong, Young-Keun;Kim, Sung-Eun;Lee, Sang-Cheon
    • Macromolecular Research
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    • v.15 no.5
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    • pp.424-429
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    • 2007
  • A procedure for the surface hydrolysis of an electrospun poly(${\epsilon}$-caprolactone) (PCL) fibrous scaffold was developed to enhance the adhesion and proliferation of osteoblasts. The surface hydrolysis of fibrous scaffolds was performed using NaOH treatment for the formation of carboxyl groups on the fiber surfaces. The hydrolysis process did not induce deformation of the fibers, and the fibers retained their diameter. The cell seeding density on the NaOH-treated PCL fibrous scaffolds was more pronounced than on the non-treated PCL fibers used as a control. The alkaline phosphatase activity, osteocalcin and a mineralization assay strongly supported that the surface-hydrolyzed PCL fibrous scaffolds provided more favorable environments for the proliferation and functions of osteoblasts compared to the non-treated PCL fibrous scaffolds use as a control.

Condensation of Nano-Size Polymer Aggregates by Spin Drying

  • Ishikawa, Atsushi;Kawai, Akira
    • Journal of Adhesion and Interface
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    • v.6 no.1
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    • pp.7-10
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    • 2005
  • Condensation control of nano-particles has become important in order to fabricate minute condensed structures. In this study, we focus our attention on condensation mechanism of polymer aggregates in a resist film. The polymer aggregate is structural component of a resist material which is used in lithography process. The condensation nature of polymer aggregates in the resist film surface is observed by using atomic force microscope (AFM). By using the AFM, the condensation of polymer aggregates can be observed clearly. The condensation of polymer aggregate strongly affects to precise fabrication of resist pattern below 100nm size. The interaction force among polymer aggregates can be analyzed based on Derjaguin approximation. We also discuss about condensation nature of polymer aggregates in the resist film surface with the help of micro sphere model.

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Linear Ion Beam Applications for Roll-to-Roll Metal Thin Film Coatings on PET Substrates

  • Lee, Seunghun;Kim, Do-Geun
    • Applied Science and Convergence Technology
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    • v.24 no.5
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    • pp.162-166
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    • 2015
  • Linear ion beams have been introduced for the ion beam treatments of flexible substrates in roll-to-roll web coating systems. Anode layer linear ion sources (300 mm width) were used to make the linear ion beams. Oxygen ion beams having an ion energy from 200 eV to 800 eV used for the adhesion improvement of Cu thin films on PET substrates. The Cu thin films deposited by a conventional magnetron sputtering on the oxygen ion beam treated PET substrates showed Class 5 adhesion defined by ASTM D3359-97 (tape test). Argon ion beams with 1~3 keV used for the ion beam sputtering deposition process, which aims to control the initial layer before the magnetron sputtering deposition. When the discharge power of the linear ion source is 1.2 kW, static deposition rate of Cu and Ni were 7.4 and $3.5{\AA}/sec$, respectively.

Fusobacterium nucleatum GroEL signaling via Toll-like receptor 4 in human microvascular endothelial cells

  • Lee, Hae-Ri;Choi, Bong-Kyu
    • International Journal of Oral Biology
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    • v.37 no.3
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    • pp.130-136
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    • 2012
  • The GroEL heat-shock protein from Fusobacterium nucleatum, a periodontopathogen, activates risk factors for atherosclerosis in human microvascular endothelial cells (HMEC-1) and ApoE-/- mice. In this study, we analyzed the signaling pathways by which F. nucleatum GroEL induces the proinflammatory factors in HMEC-1 cells known to be risk factors associated with the development of atherosclerosis and identified the cellular receptor used by GroEL. The MAPK and NF-${\kappa}B$ signaling pathways were found to be activated by GroEL to induce the expression of interleukin-8 (IL-8), monocyte chemoattractant protein 1 (MCP-1), intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), E-selectin, and tissue factor (TF). These effects were inhibited by a TLR4 knockdown. Our results thus indicate that TLR4 is a key receptor that mediates the interaction of F. nucleatum GroEL with HMEC-1 cells and subsequently induces an inflammatory response via the MAPK and NF-${\kappa}B$ pathways.

Molecular Dynamics Simulation of Deformation of Polymer Resist in Nanoimpirnt Lithography (나노임프린트 리소그래피에서의 폴리머 레지스트의 변형에 관한 분자 동역학 시뮬레이션)

  • Kang, Ji-Hoon;Kim, Kwang-Seop;Kim, Kyung-Woong
    • Proceedings of the KSME Conference
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    • 2004.11a
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    • pp.410-415
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    • 2004
  • Molecular dynamics simulations of nanoimprint lithography in which a stamp with patterns is pressed onto amorphous poly-(methylmethacrylate) (PMMA) surface are performed to study the deformation of polymer. Force fields including bond, angle, torsion, inversion, van der Waals and electrostatic potential are used to describe the intermolecular and intramolecular force of PMMA molecules and stamp. Periodic boundary condition is used in horizontal direction and $Nos\acute{e}$-Hoover thermostat is used to control the system temperature. As the simulation results, the adhesion forces between stamp and polymer are calculated and the mechanism of deformation are investigated. The effects of the adhesion force and friction force on the polymer deformation are also studied to analyze the pattern transfer in nanoimprint lithography. The mechanism of polymer deformation is investigated by means of inspecting the indentation process, molecular configurational properties, and molecular configurational energies.

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Listeria monocytogenes Biofilms in Food Processing Environments (식품공정환경에서의 Listeria monocytogenes의 바이오필름)

  • Yun, Hyun-Sun;Kim, Sae-Hun;Jean, Woo-Min
    • Journal of Dairy Science and Biotechnology
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    • v.27 no.2
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    • pp.43-48
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    • 2009
  • Listeria monocytogenes is a major concern in food processing environments because it is ubiquitous and can easily contaminate food during processing. Contaminated food and the surfaces in food facilities can serve as reservoirs of L. monocytogenes, which can lead to the serious foodborne illness listeriosis in consumers. L. monocytogenes can adhere to materials commonly used in food processing equipment and form biofilms. In the biofilm mode, L. monocytogenes is significantly more resistant to disinfection or sanitizers than its planktonic counterparts. Many researchers have studied the effects of surface materials on bacterial adhesion and the formation of biofilms. Recent studies have focused on preventing the establishment of L. monocytogenes in niches in the food plant environments.

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Study on Antitumor Activity of Samiyeongeontanggamibang(SYTG) (사미연견탕가미방(四味軟堅湯加味方)이 항암(抗癌) 및 항전이(抗轉移) 효과(效果)에 미치는 영향)

  • Bae, Moon-Yong;Kang, In-Cheol;Kim, Sung-Hoon
    • THE JOURNAL OF KOREAN ORIENTAL ONCOLOGY
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    • v.5 no.1
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    • pp.33-46
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    • 1999
  • To evaluate the antitumor and antimetastatic effects of Samiyeongeontanggamibang(SYTG), We have examined whether SYTG can inhibit the growth of several tumor cell lines, tumor cell adhesion, experimental tumor metastasis and increase survival rate of tumor-bearing mice by inhibition of DNA topoisomrase activity. The results were obtained as follows: 1. SYTG extracts revealed an efficient cytotoxicity against A549, SK-OV-3, B16-F10, and SK-MEL-2 cell lines. 2. SYTG extracts inhibited DNA topo-isomerase I from calf thymus. 3. The T/C% in S-180 bearing ICR mice treated with SYTG was 115.8% 4. SYTG extracts significantly inhibited adhesion of A549 cell to complex extracellular matrix. 5. In pulmonary colonization assay, SYTG suppressed lung metastases in tumor cell-injected mice. 6. In CAM assay, SYTG extracts inhibited angiogenesis at $15{\mu}g/egg$ concentration as compared with control. These results suggested that SYTG extracts might be a potent inhibitor of cancer.

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Preparation and Physical Properties of Poly(lactic acid) Bio-Composites using Surface Modified Microfibriled Celluloses

  • Yeo, Jun-Seok;Seong, Dong-Wook;Hwang, Seok-Ho
    • Elastomers and Composites
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    • v.50 no.1
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    • pp.62-67
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    • 2015
  • The surface modification of microfibriled cellulose (MFC) was carried out through the hydrolysis-condensation reaction using (3-aminopropyl)triethoxysilane (APS) and 3-glycidyloxypropyltriethoxysilane (GPS) and then the modified cellulose was compounded with bio-degradable poly(lactic acid) (PLA). Also, pristine MFC was compounded with PLA as a control groups. The confirmation of surface modification for the pristine MFC was characterized by FT-IR and SEM/EDX. The thermal and mechanical properties of the PLA/MFC composites depended on the content of MFC and the type of silane coupling agents. From the thermal, morphological and mechanical behaviors of the PLA/MFC composites, it was found that GPS-MFC was more successful to improve the interface adhesion between PLA matrix and the surface of MFC than that of APS-MFC.