• Journal of the korean academy of Pediatric Dentistry
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• v.47 no.3
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• pp.257-265
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• 2020

This study was performed to evaluate the restoration combined with resin infiltration (RI) of early cavitated smooth surface caries lesion in terms of microleakage. Flowable resin and resin-modified glass ionomer cement (RMGIC) were compared. Sound 20 extracted 3rd molars were divided into 2 groups randomly. Artificial decalcified lesion was induced. Cavities were prepared on the mesial and distal surfaces, and randomly set as experimental and control group. RI was applied to the experimental group before cavity restoration. The control group was restored without RI. In group I and II, flowable resin and RMGIC was used for restoration respectively. After thermocycling and silver nitrate immersion, microleakage was assessed by μ-CT. Depth of microleakage was lower in experimental group than control group only in group II (p = 0.05). Microleakage depth was lower in group II than group I in both experimental and control groups (p = 0.05). RI pretreatment before restoration of early cavitated caries lesions might reduce the microleakage and help long-term maintenance of restoration. In this study, RMGIC was less polymerization shrinkage. Restoration with RMGIC after RI pretreatment reduced the microleakage of the restoration compared to the flowable resin.

• BMB Reports
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• v.41 no.4
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• pp.287-293
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• 2008

In a yeast two-hybrid screen, we identified the microtubule-destabilizing protein SCG10 as a potential effector protein of $BRI_3$. The association was verified using GST pull-down, Co-IP, and their perinuclear co-localization. The analysis of in vitro microtubule polymerization/depolymerization showed that the binding of $BRI_3$ to SCG10 effectively blocked the ability of SCG10 to induce microtubule disassembly, as determined by turbidimetric assays. In intact PC12 cells, $BRI_3$ exhibited the ability to stabilize the microtubule network and attenuate the microtubule-destabilizing activity of SCG10. Furthermore, co-expression of $BRI_3$ with SCG10 attenuated SCG10-mediated PC12 cell neurite outgrowth induced by NGF. These results identify a novel connection between a neuron-specific BRI protein and the cytoskeletal network, suggesting possible roles of BRI3 in the process of neuronal differentiation.

• Composites Research
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• v.32 no.6
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• pp.335-341
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• 2019

In this study, an acrylic acid (AAc) was grafted on a polypropylene (PP) nonwoven fabric using electron beam irradiation. Electron beam grafting was carried out under various conditions to produce AAc grafted PP (PP-g-AAc) nonwoven fabric having a grafting yield of about 50% at radiation dose of 100 kGy and a monomer concentration of 60%. The physical and chemical properties of PP-g-AAc nonwoven fabric were evaluated by SEM, ATR-FTIR, thermal analysis and tensile strength. The morphology of PP and PP-g-AAc nonwoven fabric confirmed by SEM showed no significant change, and it was judged that AAc was introduced into PP nonwoven fabric from ATR-FTIR. PP-g-AAc nonwoven fabric showed an increase in tensile strength and a decrease in tensile strain compared to PP nonwoven fabric. However, since change of value is not significant, it is considered that there is no significant influence on the physical characterization. Adsorption experiments of PP-g-AAc nonwoven fabric on various ions showed selective adsorption behavior for lead ion. In conclusion, the electron beam radiation-induced PP-g-AAc nonwoven fabric is expected to be applied as an effective adsorbent for the adsorption of lead ions.

• Journal of Life Science
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• v.27 no.6
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• pp.632-639
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• 2017

Mature haptoglobin (Hp) is a plasma glycoprotein and acts as an antioxidant by scavenging cell-free hemoglobin (Hb). Prohaptoglobin (proHp) is an unprocessed Hp precursor which is present a little in circulation. However, the biological function of proHp remains unknown. To investigate the structural and functional differences between proHp and Hp, we prepared recombinant proHp isoforms and compared their sialic acid content and Hb-binding capacity with those of mature isoforms. When proHp samples were analyzed by Western blot under non-reducing conditions, proHp1 was detected as one band of approximately 130 kDa and proHp2 as multiple bands >200 kDa, in the manner of mature Hp1-1 and Hp2-2, respectively. On the native polyacrylamide gel under non-reducing and non-denaturing conditions, both proHp isoforms migrated more slowly than their mature Hp counterparts. In addition, the lectin-based ELISA assay demonstrated that the content of sialic acid in proHp1 and proHp2 was much less than in Hp1-1 and Hp2-2. The Hb-binding capacity of proHp was also lower than those of mature Hp. These findings indicate that proHp and Hp are similar in the size and polymerization pattern, but different in sialic acid content and Hb-binding activity. It suggests precursor proHp may exert different functions in circulation than does mature Hp.

• Korean journal of food and cookery science
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• v.4 no.1
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• pp.1-8
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• 1988

The physicochemical properties and gel-forming properties of corn & red bean crude starches were investigated. The results were as follows: 1. The shape of corn crude starch granule was polygonal and the mean value of minor axis and major axis were $11.5\mu\textrm{m}$ and $14.9\mu\textrm{m}$, respectively. In the meantime, the shape of red bean crude starch granule was oval and the mean value of minor axis and major axis were $22.3\mu\textrm{m}$ and $31.4\mu\textrm{m}$. 2. Amylose content of corn and red bean refined starch were 16.52 and 43.61% respectively. 3. Blue value of corn and red bean crude starch were 0.099 and 0.842, respectively. 4. Amylose of corn had molecular weight of 107,000 and degree of polymerization of 660. Amylopectin had degree of branching of 6.9 per 100 glucose units and glucose units of 14.6 persegment of amylopectin. Amylose of red bean had molecular weight of 118,000 and amylopectin had degree of branching of 5.2. 5. Water binding capacities of corn and red bean starch were 238.5 and 284.8. 6. Both swelling powers of corn and red bean starch were increased rapidly from $70^{\circ}C$ to $90^{\circ}C$. 7, Gelatinization of corn and red bean were 75.6 and $61.8^{\circ}C$. 8. Brabender hot-paste viscosities of corn at 6% and 8% showed the similar amylogrm patterns with peak viscosity. And red bean had no peak viscosity. 9. The difference of sensory characteristics for ‘Mook’ and kidney bean & red bean starch gels was significant.

• Advances in concrete construction
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• v.10 no.5
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• pp.403-416
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• 2020

This study investigated the effect of alkaline activators - NaOH_aq (NH) (NH: 0-16 M) and Na₂SiO_3aq (NS) (NS/NH: 0-3.5) in the synthesis of silico-manganese fume (SMF) and ground blast furnace slag (BFS) blended alkali-activated mortar (AASB). The use of individual activator was ineffective in producing AASB of sufficient fresh and hardened properties, compared to the synergy of both activators. This may be attributed to incomplete dissolution and condensation of oligomers required for gelation of the binder. An inverse relationship was noted among the fresh properties and the NH concentration or NS/NH ratio. This was influenced by the dissolution and condensation of silicate monomers under polymerization process. The maximum 28-day strength of ~45 MPa, setting time of 60 min and flow of 182 mm was obtained with the use of combined activators (10M-NH and NS/NH=2.5). The combined activators at NS/10M-NH=2.5 constituted SiO₂/Na₂O, H₂O/Na₂O and H₂O/SiO₂ molar ratio of 1.61, 17.33 and 10.77, respectively. This facilitated the formation of C-S-H, C/K-A-S-H and C-Mn-S-H in the framework together with an increase in the crystallinity due to more silicate re-organization within the aluminosilicate chain. On comparison of the high concentrated with mild alkali synthesized product, it revealed that the concentration of OH^- and Si monomers together with alkali metals influenced the dissolution of precursors and embedment of the constituent elements in the polymeric matrix. These factors eventually contributed to the microstructural densification of the mortar prepared with NS/10M-NH=2.5 thereby enhancing the compressive strength.

• Journal of the Korean Chemical Society
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• v.50 no.3
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• pp.216-223
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• 2006

To increase the stability of liposomes in blood circulation, surface modification of liposomes by incorporating a lipid-polymer derivative in the lipid bilayer or conjugating a hydrophilic polymer to the liposomal surface has been developed. In this study, the comblike copolymer, poly(HEMA-co-HPOEM), having multiple polyethyleneoxide side chains was prepared by free radical polymerization of hydroxyethylmethacrylate (HEMA) and hydroxypolyoxyethylenemethacrylate (HPOEM) as vinyl monomers. Poly(HEMA-co-HPOEM) was conjugated to the liposomal surface and the characteristics of the modified liposomes in serum were investigated. Conjugation of poly(HEMA-co-HPOEM) to liposomes increased the particle size of the liposomes by 30 nm and decreased the absolute value of zeta potential of the liposomes by shielding the negative charge of liposomal surface. Loading efficiency of model drug, doxorubicin, in liposomes was about 90% and the efficiency was not affected by conjugation of poly(HEMA-co-HPOEM) to liposomes. The particle size of poly(HEMA-co-HPOEM)-conjugated liposomes in serum did not changed and the protein adsorption was lower than that of control liposomes or liposomes containing polyethyleneoxide-lipid derivative (PEG-liposomes). These results suggest that poly(HEMA-co-HPOEM) is efficient for the stabilization of liposomes in blood circulation.

• Journal of the Korean Chemical Society
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• v.41 no.7
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• pp.337-342
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• 1997

Acryloylmethylbenzo-15-crown-5 was prepared from the reaction of 4'-hydroxymethylbenzo-15-crown-5 with acryloyl chloride. And, poly(acryloylmethylbenzo-15-crown-5) [poly(AMB15C5)] was synthesized by radical polymerization using AIBN as initiator in benzene. Coated wire lead(II) ion-selective electrodes ($Pb^{2+}$-CWISEs) using either poly(AMB15C5) or B15C5 as neutral carrier were prepared, respectively. $Pb^{2+}$-CWISEs gave linear responses with slopes of 28$\pm$ 1mV per decade within the concentration range of $10^{-5} M{\sim}10^{-1}$ M, respectively. Also, the detection limits were $10^{-6}$ M and response times were either 3 or 5 min. for B15C5 and poly(AMB15C5), respectively. $Pb^{2+}$-CWISE base on B15C5 was rather unstable than poly(AMB15C5)'s due to solubility of the B15C5 in water. The selectivity coefficients of a variety of interfering ions such as $Mg^{2+},\; Ca^{2+},\; Co^{2+},\; Ni^{2+},\; Cu^{2+},\; Zn^{2+}$ and $Cd^{2+}$ were small ($10^{-4}{\sim}10^{-5}$), while those of $Na^+$ and $K^+$ were large (0.1∼0.01). In addition, the electrode responses depended upon the pH of test solution and the composition of the membrane. In the range pH 3∼6 of test solution, potentials of Pb2+-CWISEs were hardly changed. The optimal contents of B15C5 and poly(AMB15C5) were 7.7 wt% and 13.1 wt%, respectively.

• Elastomers and Composites
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• v.47 no.1
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• pp.43-53
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• 2012

A suspension copolymerization of styrene and butyl methacrylate (BMA) in the aqueous phase was conducted at a selected temperature between 65 and $95^{\circ}C$. Hydrophobic silica was selected as a stabilizer and azobisisobutyronitrile (AIBN) as an initiator. Optimum dispersion of silica in water was obtained at pH 10 while polymerization reaction was run at pH 7. TGA and EDS measurements revealed that 90% of silica functioned as a stabilizer and 10% were incorporated into polymeric particles. Average particle diameter decreased with increasing amounts of stabilizer. Molecular weights displayed an increase when the stabilizer concentration reached 1.67 wt%. An increase in the initiator concentration and/or reaction temperature raised the reaction rate but decreased molecular weights. Particle diameter was nearly independent of the initiator concentration and reaction temperature. An increase in the BMA proportion decreased the glass transition temperature and increased the particle diameter with irregularity in shape. Incorporation of carbon black into the particles composed of styrene and BMA prolonged the reaction time before reaching completion. We have confirmed that a suspension copolymerization of styrene and BMA with hydrophobic silica as a stabilizer can produce spherical composite particles with $1-30{\mu}m$ in diameter containing carbon black.

• Applied Chemistry for Engineering
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• v.5 no.3
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• pp.395-405
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• 1994

The various functional groups, such as hydroxyl(-OH), carboxyl(-COOH) and quinonic oxygen(OC<) on the carbon black(abbreviated to CB) surface were activated with n-butyl lithium solution in n-hexane and then acrylate and methacrylate monomers were graft polymerized onto these activated anionic sites and CB-grafted polymers were obtained. To separate homopolymers from reaction mixture, non-solvent precipitation method or centrifugal separating method were applied. Subsequently, conversion, grafting ratio and efficiency were determined at various reaction temperatures and times. In case of acrylates, the grafting ratio showed 20~30% but methacrylates showed 150~200%. Also the anion polymerizations between CB and monomers were nearly reached to equilibrium state within one or two hours under each reaction temperatures but conversion and grafting ratio were increased a little with reaction temperature increase. In colloidal dispersion stability test, before heat-drying, the all CB-grafted polymers showed good dispersed stability in good solvents for acrylic and methacrylic homopolymers. Futhermore, CB-polymethacrylates were found to show excellent collidal properties for good solvents of methacrylic homopolymer even after heat-drying. Identification of the grafted polyacrylates and polymethacrylates onto the CB surface was performed by FT-IR spectroscopy. In addition, electric resistance values of CB-grafted polymers were measured by Four-probe method, and the increase of the grafting ratio showed the increase of the surface resistance.