• Journal of Nutrition and Health
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• v.38 no.9
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• pp.689-697
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• 2005

This study was conducted to fine out the preventive effects of chitosan and chitosan oligomer on the disorders of hepatic functions and lipid metabolism induced by 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD) using adult male rats (SD) for four weeks. Rats were fed chitosan ($4\%$) or chitosan oligomer ($4\%$) diets respectively before 3weeks of TCDD treatment (50 ug/kg BW) by intraperitoneal injection and then continually supplied these diets for one week until being sacrificed. The elevation of serum total and LDL cholesterol levels induced by TCDD treatment was significantly reduced in the rats fed chitosan diets. The increment of liver triglyceride levels caused by TCDD treatment was tended to suppress in all rats fed chitosan and chitosan oligomer diets. Fecal total lipid and cholesterol excretion were high levels in the rats fed chitosan diets. The hepatic cytosolic catalase activities significantly decreased by TCDD treatment appeared recovering trend by chitosan diets. In hepatic microsomal cytochrome p-450, NADPH cytochrome p-450 reductase, ethoxycoumarin-o-deethylase (ECOD) and benzphetamin N-demethylase (BPND) chitosan than chitosan oligomer diets apparently decreased the increasing levels by TCDD treatment. In histochemical observation the fat droplets and apoptosis of hepatocytes by TCDD treatment were markedly alleviated by chitosan and chitosan oligomer diets. These results indicate that chitosan, more than chitosan oligomer can exert preventive effects on some disorders of hepatic functions and lipids accumulation by TCDD.

• Applied Chemistry for Engineering
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• v.18 no.2
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• pp.121-125
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• 2007

Siloxane monomer and oligomer were introduced to n-butyl acrylate and methyl methacrylate copolymer for improvement of water resistance and tactile sensation of acryl-type emulsion. Terpolymerimerization of n-butylacrylate, methyl methacrylate and siloxane monomer or oligomer was carried out in aqueous solution. The glass transition temperature (Tg) of terpolymer decreased with increasing siloxane monomer, however, the Tg of terpolymer increased with increasing siloxane oligomer due to the crosslinking of acrylated end group. The adhesion property and surface energy of the obtained terpolymer decreased with introducing siloxane monomer or oligomer in terpolymer. Decrement of tack and surface energy means the enhancement of water resistance and tactile sensation of the emulsion.

• Journal of Microbiology and Biotechnology
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• v.26 no.12
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• pp.2179-2183
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• 2016

Nitrilases pose attractive alternatives to the chemical hydrolysis of nitrile compounds. The activity of bacterial nitrilases towards substrate is intimately tied to the formation of large spiral-shaped oligomers. In the nitrilase CynD (cyanide dihydratase) from Bacillus pumilus, mutations in a predicted oligomeric surface region altered its oligomerization and reduced its activity. One mutant, CynD Y70C, retained uniform oligomer formation however it was inactive, unlike all other inactive mutants throughout that region all of which significantly perturbed oligomer formation. It was hypothesized that Y70 is playing an additional role necessary for CynD activity beyond influencing oligomerization. Here, we performed saturation mutagenesis at residue 70 and demonstrated that only tyrosine or phenylalanine is permissible for CynD activity. Furthermore, we show that other residues at this position are not only inactive, but have altered or disrupted oligomer conformations. These results suggest that Y70's essential role in activity is independent of its role in the formation of the spiral oligomer.

• Korean Chemical Engineering Research
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• v.46 no.1
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• pp.76-81
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• 2008

UV curable pressure sensitive adhesive (PSA) was made by blending the di-functional or hexa-functional urethane-acrylate oligomer with synthesized acrylic PSA. The change of adhesive property and removability were investigated at various oligomer contents under each oligomer. As the content of oligomer increased, the peel strength was increased before UV irradiation, but it was decreased after UV irradiation. Also, it was observed that the peel strength increased with decrease of storage modulus (G'), and that loss factor (tan ${\delta}$) of the adhesive material affected the adhesive properties and removability.

• Molecules and Cells
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• v.42 no.10
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• pp.729-738
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• 2019

Autophagy is an important process for protein recycling. Oligomerization of p62/SQSTM1 is an essential step in this process and is achieved in two steps. Phox and Bem1p (PB1) domains can oligomerize through both basic and acidic surfaces in each molecule. The ZZ-type zinc finger (ZZ) domain binds to target proteins and promotes higher-oligomerization of p62. This mechanism is an important step in routing target proteins to the autophagosome. Here, we determined the crystal structure of the PB1 homo-dimer and modeled the p62 PB1 oligomers. These oligomer models were represented by a cylindrical helix and were compared with the previously determined electron microscopic map of a PB1 oligomer. To accurately compare, we mathematically calculated the lead length and radius of the helical oligomers. Our PB1 oligomer model fits the electron microscopy map and is both bendable and stretchable as a flexible helical filament.

• Journal of the Korean Applied Science and Technology
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• v.6 no.2
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• pp.53-58
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• 1989

A series of four sodium ${\alpha}-sulfo$ fatty acid allylester oligomers such as sodium ${\alpha}-sulfo$ lauric acid allylester oligomer, sodium ${\alpha}-sulfo$ myristic acid allyl ester oligomer, sodium ${\alpha}-sulfo$ palmitic acid allyl ester oligomer and sodum ${\alpha}-sulfo$ stearic acid allyl ester oligomer were examined for surface tension, defloculation effect and emulsifying power. Also critical micelle concentration (cmc) was evaluated. Consequently, these sodium allyl ${\alpha}-sulfo$ aliphatic carboxylate aligomers show o/w type emulsifying agent and dispersion effect in 1g/100ml soulution.

• Korean Journal of Optics and Photonics
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• v.17 no.1
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• pp.23-30
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• 2006

Effects of liquid-crystal droplets size on electro-optical properties of the polymer dispersed liquid crystals are investigated experimentally The liquid crystal droplets size was varied by controlling the Laser power for phase separation and LC/oligomer composition ratio. Electro-optical switching voltage is dependent on the LC/oligomer composition ratio and liquid crystal droplet size. The experimental results showed droplet size will be small and saturation voltage is increased but rise time will be short at high power illumination laser light for phase separation.

• Journal of the Korean Applied Science and Technology
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• v.32 no.4
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• pp.718-723
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• 2015

For the fabrication of the Si negative electrode in Li-ion batteries (LIBs) containing the cross-linking polymer binder, in this work, the urethane acrylate (UA) oligomer was synthesized via a simple synthetic process. The cross-linked poly(urethane acrylate) (CPUA)/carbone black (CB)/Si composite (CPUA/CB/Si composite) was fabricated through reactions between their reactive vinyl segments in the UA oligomer. Interestingly, the CPUA/CB/Si composite showed better cycle performance than the poly(vinylidene fluoride) (PVdF)/CB/Si composite (PVdF/CB/Si composite) and the polyurethane (PU)/CB/Si composite (PU/CB/Si composite). The CPUA/CB/Si composite had the best lithiation of about $2586mAh\;g^{-1}$. The UA oligomer showed a good compatibility with the electrode materials and current collector after and before a curing process.

• Journal of the Semiconductor & Display Technology
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• v.13 no.1
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• pp.35-41
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• 2014

UV curable transparent hard coating materials have been developed to improve the mechanical and optical properties of PET substrate. The coating materials were synthesized using various urethane acrylate oligomers, monomers, photo initiators, and leveling agents. The materials were coated on PET substrates and UV cured. The hard coated PET films were shown to have the good scratch resistance and transparency. When the urethane acrylate oligomer with more functional groups was introduced into the coating solution, the mechanical and optical properties were improved. However the higher concentration of 9-functional oligomer resulted in the decrease of workability. The addition of trimethylolpropane ethoxylate$(EO/OH)_9$ triacrylate(TMPETA) to coating solution improved the workability and properties. As a result, the UV cured film from the formulation of urethane acrylate oligomer with 9-functional groups, TMPETA as a monomer, IRACURE 754 as a photo initiator and BYK-340 as a leveling agent showed the best mechanical and optical properties in this study.

• Textile Coloration and Finishing
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• v.10 no.3
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• pp.50-56
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• 1998

Nonwoven fabric was treated with chitosan solution to impart antimicrobial activities by pad-dry method. Antimicrobial activity was measured by Shake Flask Method. Two chitosans of different molecular weight(Mw) with similar degree of deacetylation(DDA) were used : ca. 1,800(chitosan oligomer : DDA 84%) and 180,000(DDA 86%). Chitosan oligomer displayed high antimicrobial activity against P. vulgaris at 0.01%, S. aureus and E. coli at 0.05% treatment concentration, shelving above 90% of reduction rate. Chitosan of Mw 180,000 was effective against S. aureus, E. coil and P. vulgaris at 0.05% treatment concentration, showing almost 100% reduction rate. While chitosan of Mw 180,000 shelved reduction rate above 75% against K. pneumoniae and P. aeruginosa at 0.5% treatment concentration, chitosan oligomer was not effective against them. Fabrics become stiffer and less air permeable as treatment concentration increases. Liquid strike-through time of the sample treated with 0.5% chitosan oligomer solution (3.0 sec) was comparable with a hydrophilic finished sample commercially available(2.6 sec).