• Title/Summary/Keyword: Surface Adhesion

Search Result 2,048, Processing Time 0.029 seconds

Colchicine Inhibits Integrin ${\alpha}_5{\beta}_1$ Gene Expression during PMA induced dDfferentiation of U937 Cells

  • Jang, Won-Hee;Rhee, In-Ja
    • Archives of Pharmacal Research
    • /
    • v.18 no.6
    • /
    • pp.376-380
    • /
    • 1995
  • Monocyte adhesion involves specific cell surface receptors, integrins and results in cell differentiation. We have studied expression and regulation of integrin .${\alpha}_5{\beta}_1$ during differntiation of U937 as in vitro model. To determine expression of integrin ${\alpha}_5{\beta}_1$ during differentiation of U937 as in vitro model. To determine expression of integrin ${\alpha}_5{\beta}_1$ genes by RT-PCR (reverse transcription and polymerase chain reaction) method. We determined expression of integrin ${\alpha}_5{\beta}_1$ genes by RT-PCE (reverse transcription and polymerase chain reaction) method. We found that expression of integrin .alpha.5.betha.1 was greatly increased during PMA-induced differentiation of U937 cells and also found that PMA-induced expression of integrin ${\alpha}_5{\beta}_1$ was inhibited by colchicine, microtubule depoly merizing agent. These results indicate that microtubular integrity is associated with expression of integrin. ${\alpha}_5{\beta}_1$ during PMA-induced differentiation of U937 cells.

  • PDF

Electrical properties of Organic TFT patterned by shadow-mask with all layer

  • Lee, Joo-Won;Kim, Jai-Kyeong;Jang, Jin;Ju, Byeong-Kwon
    • Proceedings of the IEEK Conference
    • /
    • 2006.06a
    • /
    • pp.543-544
    • /
    • 2006
  • Pentacene thin film transistors fabricated without photolithographic patterning were fabricated on the plastic substrates. Both the organic/inorganic thin films and metallic electrode were patterned by shifting the position of the shadow mask which accompanies the substrate throughout the deposition process. By using an optically transparent zirconium oxide ($ZrO_2$) as a gate insulator and octadecyltrimethoxysilane (OTMS) as an organic molecule for self-assembled monolayer (SAM) to increase the adhesion between the plastic substrate and gate insulator and the mobility with surface treatment, high-performance transistor with field effect mobility $.66\;cm^2$/V s and $I_{on}/I_{off}$>$10^5$ was formed on the plastic substrate. This technique will be applicable to all structure deposited at low temperature and suitable for an easy process for flexible display.

  • PDF

Evaluation of Dynamic Wettability of Liquid Zn with Steel Sheets Containing Si and Mn

  • Tanaka, Toshihiro
    • Corrosion Science and Technology
    • /
    • v.9 no.2
    • /
    • pp.87-91
    • /
    • 2010
  • It is pointed out that non-wetting behavior of liquid Zn alloy occurs on high-tensile strength steels, which usually contain Si and Mn. There have been a lot of investigations to improve the above wettability of liquid Zn alloy with steels containing Si and Mn. Although those studies evaluated the wettability qualitatively by observation of the surface of steels galvanized by Zn or exfoliation test of Zn with substrate steels and so on, it is required to evaluate the wettability of liquid Zn with steels by measuring contact angle, work of adhesion, spreading velocity etc. which are usually used to assessment of general wetting behavior. In the present work, we evaluated the wettability of liquid Zn with steels containing Si and Mn by applying a sessile drop method to measure the change in contact angle and diameter of liquid Zn droplet wetted on steels.

Effect of Initiator on Performance of Polyvinylacetate as Emulsion Adhesive

  • Lee, Kangseok;Shim, Sang Eun
    • Elastomers and Composites
    • /
    • v.50 no.4
    • /
    • pp.286-291
    • /
    • 2015
  • Polyvinylacetate (PVAc) was prepared using thermal initiation and redox initiation via emulsion polymerization at $80^{\circ}C$. The polymerization conditions had a significant effect on the properties of the synthesized PVAc. When hydrogen peroxide and tartaric acid as the initiator for redox polymerization were used, the synthesized PVAc had a low molecular weight. In comparison with thermal polymerization, smaller PVAc particles were formed during the redox polymerization due to relatively faster polymerization rate, which in turn resulted in improved adhesion property. It is considered that the rapid generation of smaller particles induces the formation of a large surface area.

A Study on the Characteristics of Sn-Cu Solder Bump for Flip Chip by Electroplating (전해도금에 의한 플립칩용 Sn-Cu 솔더범프의 특성에 관한 연구)

  • Jung, Seok-Won;Hwang, Hyun;Jung, Jae-Pil;Kang, Chun-Sik
    • Proceedings of the International Microelectronics And Packaging Society Conference
    • /
    • 2002.11a
    • /
    • pp.49-53
    • /
    • 2002
  • The Sn-Cu eutectic solder bump formation ($140{\mu}{\textrm}{m}$ diameter, $250{\mu}{\textrm}{m}$ pitch) by electroplating was studied for flip chip package fabrication. The effect of current density and plating time on Sn-Cu deposit was investigated. The morphology and composition of plated solder surface was examined by scanning electron microscopy. The plating thickness increased with increasing time. The plating rate increased generally according to current density. After the characteristics of Sn-Cu plating were investigated, Sn-Cu solder bumps were fabricated on optimal condition of 5A/dm$^2$, 2hrs. Ball shear test after reflow was performed to measure adhesion strength between solder bump and UBM (Under Bump Metallization). The shear strength of Sn-Cu bump after reflow was higher than that of before reflow.

  • PDF

Molecular Mechanisms of Synaptic Specificity: Spotlight on Hippocampal and Cerebellar Synapse Organizers

  • Park, Dongseok;Bae, Sungwon;Yoon, Taek Han;Ko, Jaewon
    • Molecules and Cells
    • /
    • v.41 no.5
    • /
    • pp.373-380
    • /
    • 2018
  • Synapses and neural circuits form with exquisite specificity during brain development to allow the precise and appropriate flow of neural information. Although this property of synapses and neural circuits has been extensively investigated for more than a century, molecular mechanisms underlying this property are only recently being unveiled. Recent studies highlight several classes of cell-surface proteins as organizing hubs in building structural and functional architectures of specific synapses and neural circuits. In the present minireview, we discuss recent findings on various synapse organizers that confer the distinct properties of specific synapse types and neural circuit architectures in mammalian brains, with a particular focus on the hippocampus and cerebellum.

A Study on the Environmental Degradation Factors and the Required Performance of the Waterproofing Materials Applied to Underground Structures in Residential Apartment Buildings- Survey Centered- (공동주택 지하구조물에 적용되는 방수재의 환경적 열화요인과 부위별 필요성능에 관한 연구-설문조사를 중심으로-)

  • An, Ki-Won;Kang, Hyo-Jin;Oh, Kyu Hwan;Kim, Soo-Yeon;Oh, Sang-Keun
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • 2017.11a
    • /
    • pp.213-214
    • /
    • 2017
  • In this study, a survey was conducted to investigate the environmental degradation factors of specific areas in residential apartment underground structures an'd the required performance attributes for waterproofing material. Based on the survey, it was concluded that joint displacement of concrete is the highest cause for problems, and the required performance was determined to high wet surface adhesion performance for waterproofing materials.

  • PDF

Emitting Properties in Poly(3-hexylthiophene) by Heat treatment (열처리한 poly(3-hexylthiophene)의 발광특성)

  • 김대중;김주승;구할본
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2001.11a
    • /
    • pp.137-140
    • /
    • 2001
  • To improve structural properties and induce higher conductivity, we have annealed emitting layer, The temperature condition was investigated by various experiment. To observe the surface morphology of emitting layer, measured the AFM and the X-ray diffraction pattern of P3HT film is shown. It is move to slightly low angles and diffraction peaks also become much sharper. After annealing of emitting layer, EL intensity and Voltage-current-luminance curve is better as compared with untreated. But PL intensity was decreased. It is known that by emission principal. After annealing of emitting layer, EL devices enhances the interface adhesion between the emissive polymer and Indium-tin-oxide electrode, which takes a critical role to improve the emitting properties of EL devices.

  • PDF

The Effect of Corona Treated on Laminating Film and Its Analytical Study by SEM (라미네이팅 필름의 코로나 처리 효과와 주사 전자현미경을 이용한 해석)

  • Kim, Jong-Gyu;Kim, Yang-Pioung
    • Journal of the Korean Graphic Arts Communication Society
    • /
    • v.26 no.2
    • /
    • pp.15-30
    • /
    • 2008
  • Studies were carried out the phenomenal observation on the effect of corona treated hotmelt laminating film in process of manufacture by 2 kinds of experiments. These are as follow: 1) In order to verify the treatment reducing value of dynes and dynes durability with the lapse of time, it was checked dynes of a pair of 4 bar discharge electrode with 9 one for 144 hr., and it show results that 9 bar discharge electrode has higher initial dynes as well as keep up 48 dynes durability long than 4 one. 2) Drawn an inference from 3 actions -Chemical-Physical-Mechanical, on laminating film in terms of SEM's observation that are the adhesive status in boundary of corona treated base film, extrusion coating hotmelt layer, and configuration of hotmelt surface after corona treated. In tandem system, EVA layers adhesion keep its stability without corona discharge treatment.

  • PDF

Effect of PVA Brush Contamination on Post-CMP Cleaning Performance (Post-CMP Cleaning에서 PVA 브러시 오염이 세정 효율에 미치는 영향)

  • Cho, Han-Chul;Yuh, Min-Jong;Kim, Suk-Joo;Jeong, Hae-Do
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.22 no.2
    • /
    • pp.114-118
    • /
    • 2009
  • PVA (polyvinyl alcohol) brush cleaning method is a typical cleaning method for semiconductor cleaning process especially post-CMP cleaning. PVA brush contacts with the wafer surface and abrasive particle, generating the contact rotational torque of the brush, which is the removal mechanism. The brush rotational torque can overcome theoretically the adhesion force generated between the abrasive particle and wafer by zeta potential. However, after CMP (chemical mechanical polishing) process, many particles remained on the wafer because the brush was contaminated in previous post-CMP cleaning step. The abrasive particle on the brush redeposits to the wafer. The level of the brush contamination increased according to the cleaning run time. After cleaning the brush, the level of wafer contamination dramatically decreased. Therefore, the brush cleanliness effect on the cleaning performance and it is important for the brush to be maintained clearly.