• Journal of Adhesion and Interface
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• v.8 no.1
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• pp.28-33
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• 2007

It is a main trend not to use organic solvents in the adhesive industry from the recent environmental and safe points of view. For example, water-based, hot-melt, or UV curable adhesives are being investigated. Several different kinds of tackifiers that are formulated in the adhesives in order to give them more functional properties like initial tack and higher adhesion, etc., have been proposed to meet the recent trend. Firstly, the characteristics and fundamental properties of the respective materials are presented. In Japan, the trend to develop the water-based adhesives is most remarkable. While the environmental regulations are getting harder, Arakawa Chemical has been spending a lot of energy for the research, and developed toluene-free and solvent free tackifier dispersions that are presented precisely.

• Textile Coloration and Finishing
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• v.31 no.2
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• pp.107-117
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• 2019

In case of pure rubber materials, the initial quality of the rubber materials would be excellent, however, the durability against external impact might be poor. In order to overcome the relatively low durability, textile cord could be employed with silicone rubber. We have studied the improvement of heat-resistant adhesion properties of silicone adhesives between silicone rubber and PET fibers by applying various conditions including dip solution recipe. The silicone rubber used was a platinum catalyst curing type and platinum catalyst type silicone adhesive was used as an adhesive to obtain an optimum adhesive force. Furthermore, the bonding mechanism between silicone and PET fiber was established.

• Transactions on Electrical and Electronic Materials
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• v.1 no.3
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• pp.23-28
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• 2000

A block-oxide layer was formed on the surface of Cu-based leadframe by chamical oxidation method in order to enhance the adhesion strength between Cu-based leadframe and epoxy molding compound (EMC) Using sandwiched double cantilever beam (SDCB) specimens, the adesion strength was measured in terms of interfacial fracture toughness, G$\sub$IC//Results showed that the black-oxide layer was composed of two kinds of layers: pebble-like Cu$_2$O layer and acicular CuO layer, At the initial stage of oxidation the Cu$_2$O layer was preferentially formed and thickened up to around 200 nm whithin 1 minute of the oxidation time. Then the CuO layer started to from atop of the Cu$_2$O layer and thickened up to around 1300 nm until 20 minutes. As soon as the CuO layer formed, the thickness of Cu$_2$O layer began to reduce and finally reached to around 150 nm. The pre-cleaned and the Cu$_2$O coated leadframes showed almost no adhesion of EMC, however, as the CuO precipitates appeared and became continuous, G$\sub$IC/ increased up to around 80 J/㎡. Further oxidation raised G$\sub$IC/ up. to around 100 J/㎡.

• BMB Reports
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• v.50 no.8
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• pp.429-434
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• 2017

Endometriosis is the abnormal growth of endometrial cells outside the uterus, causing pelvic pain and infertility. Furthermore, adhesion of endometrial tissue fragments to pelvic mesothelium is required for the initial step of endometriosis formation outside uterus. $TGF-{\beta}1$ and adhesion molecules importantly function for adhesion of endometrial tissue fragments to mesothelium outside uterus. However, the function of $TGF-{\beta}1$ on the regulation of adhesion molecule expression for adhesion of endometrial tissue fragments to mesothelium has not been fully elucidated. Interestingly, transforming growth factor ${\beta}1$ ($TGF-{\beta}1$) expression was higher in endometriotic epithelial cells than in normal endometrial cells. The adhesion efficiency of endometriotic epithelial cells to mesothelial cells was also higher than that of normal endometrial cells. Moreover, $TGF-{\beta}1$ directly induced the adhesion of endometrial cells to mesothelial cells through the regulation of integrin of ${\alpha}V$, ${\alpha}6$, ${\beta}1$, and ${\beta}4$ via the activation of the $TGF-{\beta}1/TGF-{\beta}RI/Smad2$ signaling pathway. Conversely, the adhesion of $TGF-{\beta}1-stimulated$ endometrial cells to mesothelial cells was clearly reduced following treatment with neutralizing antibodies against specific $TGF-{\beta}1-mediated$ integrins ${\alpha}V$, ${\beta}1$, and ${\beta}4$ on the endometrial cell membrane. Taken together, these results suggest that $TGF-{\beta}1$ may act to promote the initiation of endometriosis by enhancing integrin-mediated cell-cell adhesion.

• Korean Journal of Animal Reproduction
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• v.18 no.1
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• pp.63-70
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• 1994

Thirty ewes received typical trauma to their oviducts and uterine horns from surgical embryo collection procedures. Ten percent Dexamethasone was used as an irrigant on the exposed abdominal tissue prior to closing the incision. The treatment group received 17mg colchicine Om! lewe) and the control group was administered a 1.0ml placebo(PSS). Fifteen ewes that were initially treated with 17mg /im colchicine showed acute colchicine toxicity within 2-5 days after initial treatment and were removed from the study. Due to acute colchicine toxicity at 17mg, the colchicine level was lowered to 8, 4 and 2mg(4 ewes/group). Treatments consisted of daily injections of colchicine. One ewe in the 8mg group developed toxicity on day 5. Therefore, ewes were then administered colchicine every other day from day 6 to day 14 postsurgeryat 4 and 2 mg. the second laparotomy was performed 9 weeks after first treatment. Following second laparotomy, the treatment group(n=5) received 4 mg colchicine every day for 14 days and there was no clinical symptoms of colchicine toxicity. The third laparotomy was performed by the same operators 5 weeks after final treatment and the adhesions scored. Adhesion grading was based on a scale of 0-4, with 4 being the most severe. The results of adhesion grading(> 3) at second laparotomy were not significantly different(P>0.05)between the two groups. Adhesion formation observed at third laparotomy showed a reduced, but not significant reduction (P>0.05) in the colchicine-treated ewes when compared with the controls. Ten ewes(5 control and 5 treatment)were examined cytogenetically by bone marrow analysis five days post-treatment. There was no difference(P>0.05)in the incidence of numerical or structural aberrations between the two groups.

• Corrosion Science and Technology
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• v.7 no.1
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• pp.50-60
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• 2008

The majority of the described experimental results deal with relatively pure aluminium. Variations were made in the pretreatment of the aluminum substrates and an investigation was performed on the resulting changes in oxide layer composition and chemistry. Subsequently, the bonding behavior of the surfaces was investigated by using model adhesion molecules. These molecules were chosen to represent the bonding functionality of an organic polymer. They were applied onto the pretreated surfaces as a monolayer and the bonding behavior was studied using infrared reflection absorption spectroscopy. A direct and clear relation was found between the hydroxyl fraction on the oxide surfaces and the amount of molecules that subsequently bonded to the surface. Moreover, it was found that most bonds between the oxide surface and organic functional groups are not stable in the presence of water. The best performance was obtained using molecules, which are capable of chemisorption with the oxide surface. Finally, it was found that freshly prepared relatively pure aluminum substrates, which are left in air, rapidly lose their bonding capacity towards organic functional groups. This can be attributed to the adsorption of contamination and water to the oxide surface. In addition the adhesion of a typical epoxy-coated aluminum system was investigated during exposure to water at different temperatures. The coating was found to quite rapidly lose its adhesion upon exposure to water. This rapid loss of adhesion corresponds well with the data where it was demonstrated that the studied epoxy coating only bonds through physisorptive hydrogen bonding, these bonds not being stable in the presence of water. After the initial loss the adhesion of the coating was however found to recover again and even exceeded the adhesion prior to exposure. The improvement could be ascribed to the growth of a thin oxyhydroxide layer on the aluminum substrate, which forms a new, water-stable and stronger bond with the epoxy coating. Two routes for improvement of adhesion are finally decribed including an interphasial polymeric thin layer and a treatment in boiling water of the substrate before coating takes place. The adhesion properties were finely also studied as a function of the Mg content of the alloys. It was shown that an enrichment of Mg in the oxide could take place when Mg containing alloys are heat-treated. It is expected that for these alloys the (hydr)oxide fraction also depends on the pre-treatment and on the distribution of magnesium as compared to the aluminium hydroxides, with a direct impact on adhesive properties.

• Korean Journal of Environmental Biology
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• v.27 no.1
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• pp.88-94
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• 2009

The process of atherosclerosis begins through secretion of inflammatory cytokine or adhesion of leukocyte from damage in blood vessels and transmigration. This study was conducted to investigate the effects of delphinidin chloride (DC) in the initial process of atherosclerosis on the expression of ICAM-1 (Intracellular Adhesion Molecule-1) and VCAM-1 (Vascular Adhesion Molecule-1) related to adhesion of leukocyte at the HUVEC (human umbilical vein endothelial cell line. As a result, cell growth inhibition rate at 50 ${\mu}M$ was respectively 4, 3 and 5% without cell toxicity. As a result of morphological observation monocyte-endothelial cell adhesion assay and optical microscope carried out to measure attachment of mononuclear cells to endothelial cells induced by Tumor necrosis factor-alpha (TNF-$\alpha$) at concentrations without cell toxicity, DC concentration-dependently suppressed attachment. When effects on the expression of VCAM-1 and ICAM-1, cell adhesion molecules induced from endothelial cells by TNF-$\alpha$, were comparatively analyzed using western blot analysis and RT-PCR methods, protein of VCAM-1 and ICAM-1 and expression at the level of mRNA were concentration-dependently reduced. Taken together, the results of this studies provide evidence that DC possess an anti-metastatic activity.

• Journal of the Korean institute of surface engineering
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• v.31 no.1
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• pp.34-44
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• 1998

Stainless steel is being used widely lor various purposes due to its good corrosion resistance. There has becn much research to produce colored stainless sterl by several methods. In this experiment, we coated TixN film on the SUS304 substrate with thc DC magnetron sputtering system and studied the internal structurc and adhesive strength of the films as a function of the coating conditions. Before lhe specimen was coated, a sputter etching was very effective in removing the$\delta$ Fe(BCC) phase as well as the contaminant and oxide layer as well as increasing rotghness. Five-stage failure mode appeared with increased scratch load with the TIN films coated on the SUS304 in this manner ; tensile failure-,conformal failure-,buckling failure->chipping failurc and spalling Failure. When the failure was terminated at the initial stage, the film will have good adhesion. But, if syalling failure has occurred at the initial scratch, then the adhesion will be poor. The interlayer between thc coated film and thc substratc was homogeneously adhcsive when the $\gamma'-Fe_4N$ phase wasn't detected in the XRD analysis and the adhesive strength only was reduced by surPace defects. But, when the ,$\gamma'-Fe_4N$N phasc was detected in the XRD analysis, the adhesive strength was very poor.

• Journal of Periodontal and Implant Science
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• v.41 no.2
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• pp.67-72
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• 2011

Purpose: The aim of this study is to determine whether certain biomaterials have the potential to support cell attachment. After seeding bone marrow stromal cells onto the biomaterials, we investigated their responses to each material in vitro. Methods: Rat bone marrow derived stromal cells were used. The biomaterials were deproteinized bovine bone mineral (DBBM), DBBM coated with fibronectin (FN), synthetic hydroxyapatite (HA), HA coated with FN, HA coated with $\beta$-tricalcium phosphate (TCP), and pure $\beta$-TCP. With confocal laser scanning microscopy, actin filaments and vinculin were observed after 6, 12, and 24 hours of cell seeding. The morphological features of cells on each biomaterial were observed using scanning electron microscopy at day 1 and 7. Results: The cells on HA/FN and HA spread widely and showed better defined actin cytoskeletons than those on the other biomaterials. At the initial phase, FN seemed to have a favorable effect on cell adhesion. In DBBM, very few cells adhered to the surface. Conclusions: Within the limitations of this study, we can conclude that in contrast with DBBM not supporting cell attachment, HA provided a more favorable environment with respect to cell attachment.

• Journal of the Korean Society for Railway
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• v.10 no.2 s.39
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• pp.186-194
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• 2007

This study was performed to compare the load-carrying capacities of the reinforced concrete structure between the carbon fiber adhesion reinforcement method and the external post-tensioning method and further estimate the effective stress of the reinforced material by analyzing the experimental reinforcing effect of each method and the behavior resulting from each method. As a result, it was found out that the effective stress of the carbon fiber reinforcement according to the carbon fiber adhesion reinforcement method had an unexpected value, and also, bearing of the stress was found to be far from sharing thereof. That is to say, while the carbon fiber was bearing the whole stress to some limits, it got to be momentarily ruptured as soon as it went beyond such limits. On the other hand, the external post-tensioning method has the advantage of inducing an initial effective stress by introducing a strain, and thus, it was found that behavior or bearing of the stress was also found to be a solid behavior of the steel wire. This method was also found to be more efficient and excellent than the carbon fiber adhesion reinforcement method in the reinforcing effect or securing the effective stress. Accordingly, we were to discuss the effective stress as comparatively examined, focusing on deriving of the more enhanced reinforcing effect on the basis of the experiment to which the field characteristic is added.