• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1996년도 가을 학술발표회 논문집
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• pp.175-182
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• 1996

This paper deals with the properties of water permeability and porosity of cement mortar substrate coated with siliceous slurry coating under the exposure environment. Conditions of exposure enviornment are four kinds of in constant temperature water and humidity box, in indoor and outdoor exposure. Coated mortar substrate was expected continually increase in water and humidity condition, but was not in dry condition. Watertightness effect of siliceous coating was better in the condition of humidity then the dry condition, and the pore volume was decreased in that condition.

• Bulletin of the Korean Chemical Society
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• 제18권2호
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• pp.174-179
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• 1997

The synthesis and electronic as well as redox properties of four Ru(Ⅱ) complexes based on the ligand 4'-(4-pyridyl)-3,3';5',3"-bis-dimethylene-2,2';6',2"-terpyridine are reported. Each new complex is of the type [Ru(L)2]n+ and [Ru(tpy)(L)]n+, where L is the terdentate ligand with extra pyridine ring at 4'-position or is a N-methylated ligand and n=2, 3, or 4. Cyclic voltammetry indicates that the first electron added to the complex enters the viologen-type acceptor in N-methylated ligand.

• 대한치과보철학회지
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• 제33권2호
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• pp.210-230
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• 1995

To compare the wear resistance of four kinds of commercial acrylic resin teeth [SR-Orthosit PosterioresR(Ivoclar Co., Liechtenstein), Endura PosteriorR(Shofu Inc. Japan), trubyte IPN teethR(Dentsply International Inc., York,), Trubyte BiotoneR(dentsply Inermational Inc. Brazil) by means of the toothbrush abrasion method, the artificial resin teeth were embedded in epoxy resin with the occlusal surfaces aligned in one plane for a total of 40 blocks. There after, each lock was mounted in the arm of the toothbrush abrasion machine(K 236, Japan). Wear measurements were made on the three preconditioned states. Those were as follows : no treatment specimens, thermocycled specimens, and thermocycled specimens which were immeresed applied load of 400g during the buring the brushing cycle. At the end of the 30,000-stroke cycle, each specimen was removed, and weighed. The microhardness of four kinds of commercial resin teeth were determined by means of microhardness tester. Microhardness tests were performed on te no treatment specimens, thermocycled specimens, and thermocycled specimens with immersion in the denture cleansing solution. Finally, the comparison of thermal properties were perfomed using differential scanning calorimeter(DSC-1500). The following results were obtained : 1. In the case of no treatment teeth, the wear amount of endura Posterior(EN) was the greatest among the others(p<0.01), and the wear amount of three kinds of artificial resin teeth was increased in the order of Trubyte IPN teeth(IN), Trubyte Biotone(BN), SR-Orthosit Posteriores(SN) but there was no statistic significance(p>0.01). 2. The wear amount of Trubyte IPN teeth(IT) and Trubyte Biotone(BT), was increased due to thermocycling effect, but that of Endura Posteriores(ET) was decreased conversely(p<0.01). 3. Except for the SR-Orthosit Posteriores(STC), the wear amount of three kinds of artificial resing teeth(that is, ETC, ITC, BTC) was increased due to denture cleansing solution$(Cledent^R)$, but there was no statistic significance(p>0.01). But the wear amount of the SR-Orthosit Posteriores(STC) was the greatest among the others(p<0.01). 4. The wear amount of toothbrush was the greatest in case of contact with occlusal surface of SROrthosit Posteriores resin teeth(p<0.01). 5. the microhardness values(KHN) of the SR-Orthosit Posteriores was the highest among the experimental artificial resin teeth(p<0.01). 6. There was no relationship between microhardness valuse(KHN) and wear amount of four kinds of experimental artificial resin teeth(p<0.01). 7. The differential canning calorimetric property of four kinds of artificial resin teeth did not show endothermal or exothermal peak in the range of $100^{\circ}C$

• 대한한의학방제학회지
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• 제24권4호
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• pp.271-282
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• 2016

Objective : In this study, we compared the antioxidant and anticancer properties of four multi-herbal formulas which were recorded in 'Dongeuibogam': Gilgyung-tang (GGT), Mokdanpi-tang (MDPT), Samso-eum (SSE), Samchulbobi-tang (SCBBT). Methods : We checked antioxidant properties of four multi-herbal formula through total phenolic content, radical scavenging activities, protective effects on genomic DNA oxidation. To investigate anticancer effects, we conducted MTT assay and analyzed morphologic change in A549 non-small lung cancer cells. Results : Total phenolic contents of four multi-herbal formulas were in a rich order of MDPT > SSE > GGT > SCBBT. Especially, MDPT revealed the highest activity than others in all antioxidant experiments. Our results indicated that treatment of those multi-herbal formulas induced growth retardation in A549 cells and MDPT also showed the highest anticancer effect ($IC_{50}=1.374mg/ml$) among them. Conclusions : Our data suggested that MDPT would be a powerful ingredient for lung cancer treatment.

• 한국수소및신에너지학회논문집
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• 제33권3호
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• pp.209-218
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• 2022

Recently, research on the development of anion exchange membranes (AEMs) has received considerable attention from the scientific community around the world. Here, we fabricated a series of AEMs with branched structures with different alkyl spacers and conducted comparative evaluations. The introduction of these branched structures is an attempt to overcome the low ionic conductivity and stability problems that AEMs are currently facing. To this end, branched polymers with different spacer lengths were synthesized and properties of each membrane prepared according to the branched structure were compared. The chemical structure of the polymer was investigated by proton nuclear magnetic resonance, Fourier transform infrared, and gel permeation chromatography, and the thermal properties were investigated using thermogravimetric analysis. The branched anion exchange membrane with (CH₂)₃ and (CH₂)₆ spacers exhibited ionic conductivities of 8.9 mS cm^-1 and 22 mS cm^-1 at 90℃, respectively. This means that the length of the spacer affects the ionic conductivity. Therefore, this study showing the effect of the spacer length on the ionic conductivity of the membrane in the polymer structure constituting the ion exchange membrane is judged to be very useful for future application studies of AEM fuel cells.

• 한국수소및신에너지학회논문집
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• 제33권4호
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• pp.372-382
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• 2022

In this study, anion exchange membranes were prepared by synthesizing the main chain into a poly(arylene ether) (PAE) structure, and the structures capable of improving the physical and chemical stability of the membrane by introducing a heterocyclic quaternary ammonium functional groups were studied. The chemical structure and thermal properties of the prepared polymer were confirmed by ¹H-NMR, FT-IR, TGA, and DSC, and surface analysis was performed through AFM measurement. Additionally, dimensional stability and chemical properties was studied by measuring water uptake and swelling ratio, IEC and ionic conductivity. At 90℃, the quaternized poly(arylene ether) (QPAE)/1-methylpiperidine (MP) membrane exhibited the highest ionic conductivity of 27.2 mS cm^-1, while the QPAE/1-methylimidazole (MI) membrane and QPAE/1-methylmorpholine (MM) membrane exhibited values of 14.5 mS cm^-1 and 11.5 mS cm^-1, respectively. In addition, the prepared anion exchange membrane exhibited high chemical stability in alkaline solution.

• 한국축산식품학회지
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• 제44권1호
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• pp.103-118
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• 2024

The aim of this study is to compare the quality characteristics of dry-cured loins with different levels of proteolysis and lipid oxidation and to investigate the relationship between these factors on quality characteristics. The dry-cured loins were divided into four groups [proteolytic index (PI) and 2-thiobarbituric acid reactive substances (TBARS) of high levels (HH), PI of high level and TBARS of low level (HL), PI of low level and TBARS of high level (LH), and PI and TBARS of low levels (LL)] based on the proteolysis index and TBARS. Moisture, protein, and fat content were all significantly influenced by proteolysis and lipid oxidation (p<0.05). The total fatty acid content in the high proteolysis groups (HH and HL) was significantly lower than that in the low proteolysis groups (LH and LL; p<0.05). For total free amino acid content, HH was the highest, and LL was the lowest (p<0.05). On the other hand, there was no significant difference between HL and LH (p>0.05). In the amount of total volatile compounds, there was no significant difference between HH and HL (p>0.05), but LH and LL significantly differed (p<0.05). In conclusion, proteolysis and lipid oxidation can influence the quality characteristics of dry-cured loin. Additionally, proteolysis might be as influential in generating volatile compounds as lipid oxidation.

• Anatomy and Cell Biology
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• 제56권3호
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• pp.293-298
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• 2023

The mentalis muscle is a paired muscle originating from the alveolar bone of the mandible. This muscle is the main target muscle for botulinum neurotoxin (BoNT) injection therapy, which aims to treat cobblestone chin caused by mentalis hyperactivity. However, a lack of knowledge on the anatomy of the mentalis muscle and the properties of BoNT can lead to side effects, such as mouth closure insufficiency and smile asymmetry due to ptosis of the lower lip after BoNT injection procedures. Therefore, we have reviewed the anatomical properties associated with BoNT injection into the mentalis muscle. An up-to-date understanding of the localization of the BoNT injection point according to mandibular anatomy leads to better injection localization into the mentalis muscle. Optimal injection sites have been provided for the mentalis muscle and a proper injection technique has been described. We have suggested optimal injection sites based on the external anatomical landmarks of the mandible. The aim of these guidelines is to maximize the effects of BoNT therapy by minimizing the deleterious effects, which can be very useful in clinical settings.

• BMB Reports
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• 제28권5호
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• pp.451-457
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• 1995

Four carboxypeptidases, CP1, CP2, CP3, and CP4 were isolated from the cotyledons of germinating seedlings of Canavalia lineata by sequential chromatography on the following four columns: 1) CM-cellulose, 2) Sephacryl 5-300, 3) Procion red dye, and 4) Sephacryl S-200. A number of properties of the enzymes, such as substrate specificity, molecular weight, optimum pH, thermal stability, have been determined. Enzyme activities were measured using the Cbz(carbobenzoxy)-dipeptides containing phenylalanine at the penultimate position. The $K_m$ values of four carboxypeptidases for Cbz-Phe-Ala were 0.50, 0.65, 1.30, and 1.35 mM, respectively. The inhibition studies indicated that the four carboxypeptidases were all serine type. Each of the carboxypeptidases with molecular weights of 145, 114, 105, and 104 kDa, respectively, had the optimum enzyme activity at pH 5.0~6.0. And they were sensitive to high temperature.

• 대한방사성의약품학회지
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• 제6권2호
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• pp.155-164
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• 2020

Polyethylene glycol (PEG) has been the most commonly used polymer for the past few decades in the field of biomedical applications due to its gold standard stealth effect. PEGylation of antibody-drug conjugates, liposomes, peptides, nanoparticles, and proteins is done to improve their pharmaceutical efficacy and pharmacokinetic properties. PEGylation of antibodies with various PEG linkers improves targeting ability by increasing the blood circulation time and thus enhances the biodistribution profiles. It also assists in minimizing the immediate capture by the reticuloendothelial system. In this review, we summarize the effect of PEG linkers in an antibody conjugation and their pharmacokinetics in the field of biomedical imaging.