• Macromolecular Research
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• v.9 no.2
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• pp.107-115
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• 2001

Poly(L-lactide-co-glycolide)(PLGA) was blended with poly[$\omega$-methacryloyloxyethyl phospho-rylcholine-co-ethylhexylmethacrylate (PMEH)] (PLGA/PMEH) to endow with new functionality i.e., to improve the cell-, tissue- and blood-compatibility. The characteristics of surface properties were investigated by measurement of contact angle goniometer, Fourier-transform infrared spectroscopy with attenuated total reflectance (FTIR-ATR) and electron spectroscopy for chemical analysis (ESCA). NIH/3T3 fibroblast and bovine aortic endothelial cell were cultured on control and PLGA/PMEH surfaces for the evaluation of ceil attachment and proliferation in terms of surface functionality such as the concentration of phosphoryl-choline. Also, the behavior of platelet adhesion on PLGA/PMEH was observed in terms of the surface functionality. The contact angles on control and PLGA/PMEH surfaces decreased with increasing PMEH content from 75$^{\circ}$ to about 43$^{\circ}$. It was observed from the FTIR-ATR spectra that phosphorylcholine groups are gradually increased with increasing blended amount of MPC. The experimental P percent values from ESCA analysis were more 3.28∼7.4 times than that of the theoretical P percent for each blend films. These results clearly indicated that the MPC units were concentrated on the surface of PLGA/PMEH blend. The control and PLGA/PMEH films with 0.5 to 10.0 wt% concentration of PMEH were used to evaluate cell adhesion and growth in terms of phosphorylcholine functionality and wettability. Cell adhesion and growth on PLGA/PMEH surfaces were less active than those of control and both cell number decreased with increasing PMEH contents without the effect of surface wettability. It can be explained that the fibronectin adsorption decreased with an increase in the surface density of phosphorylcholine functional group. One can conclude the amount of the protein adsorption and the adhesion number of cells can be controlled and nonspecifically reduced by the introduction with phosphorylcholine group. Morphology of the adhered platelets on the PLGA/PMEH surface showed lower activating than control and the number of adhered platelets on the PLGA/PMEH sample decreased with increasing the phosphorylcholine contents. The amount of fibrinogen adsorbed on the PLGA/PMEH surface demonstrated that the phospholipid polar group played an important role in reducing protein adsorption on the surface. In conclusion, this surface modification technique might be effectively used PLGA film and scaffolds for controlling the adhesion and growth of cell and tissue, furthermore, blood compatibility of the PLGA was improved by blending of the MPC polymer for the application of tissue engineering fields.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.19
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• pp.8203-8207
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• 2014

Purpose: The aim of this study was to investigate the relationship between cell adhesion and anoikis evasion among human osteosarcoma cells (MG-63), and to further study the molecular mechanisms. Materials and Methods: Human osteosarcoma cells (MG-63) were assessed for apoptosis, and caspase-3, E-cadherin and ${\beta}$-catenin expression in EDTA and control non-EDTA groups. Results: MG-63 cells were predominantly aggregated when in suspension, and the suspended cells were more dispersed in the EDTA group. Following culture in suspension for 24 h, 48 h, or 72 h, the rates of apoptosis were $34.88%{\pm}3.64%$, $59.3%{\pm}7.22%$ and $78.5%{\pm}5.21%$ in the experimental group and $7.34%{\pm}2.13%$, $14.7%{\pm}3.69%$, and $21.4%{\pm}3.60%$ in the control group, respectively. Caspase-3 expression progressively increased and E-cadherin and ${\beta}$-catenin were decreased in the experimental group, whereas there was no change in the control group. Conclusions: MG-63 cells could avoid anoikis through cell adhesion, and E-cadherin might play a role in this process.

• Journal of Aerospace System Engineering
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• v.15 no.3
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• pp.87-92
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• 2021

In this study, a numerical approach was utilized to observe the phenomena in the ground combustion test of a gas generator for a ducted rocket with a plunger-type flow control device. The design factors were also identified through the analysis. It was observed that the pressure increase without the adhesion of the combustion product at the discharge pipe was quite similar to the analysis assuming a cone-shaped erosive burning effect. The pressure increase in most cases was similar to the analysis results when assuming the change in discharge pipe area due to the adhesion of combustion products. Moreover, it was also established that for a given grain shape and discharge flow area, the effect of the adhesion of combustion products has a significant effect on the combustion chamber pressure for cases over n=0.45.

• Korean Circulation Journal
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• v.53 no.2
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• pp.92-102
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• 2023

Background and Objectives: YKL-40 is considered to be associated with cardiovascular disease (CVD). In this study, the effect of serum 25(OH) vitamin D [25(OH)VitD] differences between groups on YKL-40 was evaluated on a hypercholesterolemia rat model. Methods: Thirty-two male rats (wistar albino) were equally divided into 4 groups. The first group was the control group; the second group was high-cholesterol (H-CH) adequate vitamin D (VitD) group (H-Ade^VD). The third group was the H-CH deficient VitD group (H-Def^VD), and the last group was designed with the H-CH supplement VitD (H-Sup^VD). The feeding process consisted of 2 stages. At the first stage (5 months), the H-Def^VD group was fed on VitD deficient chow, while the other groups (control, H-Ade^VD, H-Sup^VD) were fed on standard chow. At the second stage (3 months), the H-Ade^VD and the H-Sup^VD groups were fed on the H-CH chow, whereas the H-Def^VD group was fed on the H-CH-VitD deficient chow. Moreover, the H-Sup^VD group was given 100 IU/kg/day VitD along with the H-CH chow. Results: Compared with the control group, interleukin-6 (IL-6), soluble intercellular adhesion molecule-1 (sICAM-1), soluble vascular cell adhesion molecule-1 (sVCAM-1), and YKL-40 values in the H-Def^VD groups increased significantly (p<0.001, p<0.001, p=0.009, p=0.005; sequentially). Conclusion: It can be concluded that VitD can suppress the YKL-40, thus, it will prevent CVD development in rat. Therefore, further clinical studies related with human will reveal the effect of VitD and YKL-40 on CVD development.

• The Korean Journal of Food And Nutrition
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• v.23 no.2
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• pp.147-153
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• 2010

Sulgidduk samples containing 1, 2, and 4% Adenophora remotiflora powder and a control were examined for moisture content, gelatinization property, color, textural characteristics, and sensory qualities to determine the optimal ratio of Adenophora remotiflora powder in the formulation. The highest viscosity, lowest viscosity, final viscosity, setback and breakdown decreased as the contents of Adenophora remotiflora powder increased in the gelatinization property of flour blends of rice cake made with Adenophora remotiflora powder. The water content of rice cake with Adenophora remotiflora powder was 40.54~41.30% and there was no significant difference between samples with Adenophora remotiflora powder. L values indicating brightness were highest in the control group and all of the a values displayed green color indicating that they were negative. The b values were lowest in the control group and the values increased as the level of Adenophora remotiflora powder increased. Evaluation of the mechanical characteristics of rice cake with Adenophora remotiflora powder, hardness, cohesion, adhesion and chewiness were all higher in the control group and as its contents were rich, such properties were reduced. In addition, there was no significant difference between adhesion and chewiness. Adhesion and elasticity were low in the control group and as its contents were rich, such properties increased. The results of the sensory test revealed that the, control group containing 1% Adenophora remotiflora powder had the highest color, flavor, taste and overall preference.

• The Journal of Advanced Prosthodontics
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• v.8 no.4
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• pp.290-295
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• 2016

PURPOSE. The aim of this study was to evaluate the effect of paracetic acid (PAA) and ozone disinfection on the tensile bond strength (TBS) of silicone-based resilient liners to acrylic resins. MATERIALS AND METHODS. One hundred and twenty dumbbell shaped heat-polymerized acrylic resins were prepared. From the mid segment of the specimens, 3 mm of acrylic were grinded off and separated parts were reattached by resilient liners. The specimens were divided into 2 control (control1, control7) and 4 test groups of PAA and ozone disinfection (PAA1, PAA7, ozone1 and ozone7; n=10). While control groups were immersed in distilled water for 10 min (control1) and 7 days (control7), test groups were subjected to PAA (16 g/L) or ozone rich water (4 mg/L) for 1 cycle (10 min for PAA and 60 min for ozone) per day for 7 days prior to tensile tests. Measurements of the TBS were analyzed using 3-way ANOVA and Tukey's HSD test. RESULTS. Adhesive strength of Mollosil decreased significantly by application of ozone disinfection. PAA disinfection had no negative effect on the TBS values of Mollosil and Molloplast B to acrylic resin. Single application of ozone disinfection did not have any negative effect on TBS values of Molloplast B, but prolonged exposure to ozone decreased its adhesive strength. CONCLUSION. The adhesion of resilient liners to acrylic was not adversely affected by PAA disinfection. Immersion in ozonated water significantly decreased TBS of Mollosil. Prolonged exposure to ozone negatively affects adhesion of Molloplast B to denture base materials.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.813-818
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• 2005

In this paper, a re-adhesion control scheme is proposed for 1C2M propulsion system of TTX. The possibility of slip between wheel and rail in railway system is increasing because of the tendency of high speed and a climatic change. This slip results in the decrease of adhesive effort between this wheel and rail, so the control strategy of traction effort which can reduce the speed promptly and make most use of the maximum adhesive force is absolutely necessary. This paper describes the modeling of the TTX system, and this system is verified by the simulation.

• Proceedings of the KIEE Conference
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• 1999.07a
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• pp.461-464
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• 1999

To improve traction effort performance and stability for the Korean High-Speed Railway Train, practical re-adhesion controller including a novel anti-slip control scheme is proposed. The presented method is verified by train running simulation results based on induction motor vector control with PWM inverter.

• Korean Journal of Bronchoesophagology
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• v.5 no.2
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• pp.174-181
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• 1999

The palatine tonsils(tonsils) and pharyngeal tonsils(adenoids) are situated at the entrance of the respiratory and alimentary tracts and represent the first site of contact with a variety of microorganisms and other antigens present in food and inhaled air. They are known as lymphoid organs carrying out the function of cellular and humoral immunity, and so they form a local protective barrier. And the expression of the vascular endothelial adhesion molecules is known to play an important role for the inflammatory reaction in tonsils and adenoids as well as in other inflammatory tissues, by binding with the receptors on the surface of leukocytes. But although several scientific hypotheses on the role of these lympoid tissues have been suggested, their complete functions have remained unknown. The purpose of this study is to present an basic data of the knowledge on the immunologic physiology of the tonsils and adenoids and their role as active immunologic organs that reinforce the mucosal immunity of the entire upper aerodigestive tract. We examined 16 human tonsils and adenoids and the expression of three endothelial adhesion molecules, vascular endothelial adhesion molecule-1(VCAM-1), intracellular adhesion molecule-1(ICAM-1), and E-selection, in tissue sections using immunohistochemistry. We used the inferior turbinate mucosa obtained from 9 patients getting septal surgery as a control group. The expressions of vascular endothelial adhesion molecule-1(VCAM-1) and intracellular adhesion molecule-1 (ICAM-1) were significantly higher in the tonsils and adenoids. But respectively, there were no significant differences between the tonsils and adenoids. The expression of E-selection was significant higher in the tonsils, but not in the adenoids. We observed that tonsils and adenoids showed significantly higher expressions of vascular endothelial adhesion molecule-1(VCAM-1), intracellular adhesion molecule-1(ICAM-1), and E-selection (in the case of E-selection, only in the tonsils). We propose that these adhesion molecules play an important role for the immunologic reaction by the transendothelial migration of lymphocytes and binding with the receptors on the surface of leukocytes.

• Food Science of Animal Resources
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• v.24 no.1
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• pp.86-91
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• 2004

The ability of probiotics containing Lactobacillus acidophilus to adhere to the intestinal epithelium may play an important role in colonization of the gastrointestinal tract and preventing enteric pathogen such as enterohemorrhagic E. coli(EHEC O157:H7. In the study, we investigated the adhesion to human intestinal epithelial cells(HT-29) of strains of L. acidophilus(3 from human, 2 from pig, and 1 from calf). All of the tested strains of L. acidophilus were highly observed adhesion ability(from 10$\^$6/ to 10$\^$7/ cfu/mL), compared to L. rhamnosus GG as control. Also, adhered strains of L. acidophilus were significantly preserved in serial wash-out steps. However, no correlation could be observed between cell surface hydrophobicity and adhesion abilities of the tested strains of L. acidophilus. Inhibition of adhesion of EHEC O157:H7 was also examined, a 2 log cycle reduction was observed by all of the tested strains of L. acidophilus. These results suggest that the strains of L. acidophilus with high adhesion ability are resistant to wash-out and adhesion ability inhibition by selected strains of L. acidophilus helps to prevent adhesion of EHEC O157:H7 to intestinal epithelial cells.