• 한국식품영양학회지
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• 제22권2호
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• pp.308-312
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• 2009

저분자량 키토산 올리고당의 세포 독성을 실험하였다. 저분자량 키토산 올리고당은 정상세포주인 Vero E6(Africa green monkey kidney cell)에 대한 세포 독성을 거의 나타내지 않았다. 정상세포주에 대한 저분자량 키토산 올리고당의 $IC_{50}$값은 $1,060.28{\mu}g/m{\ell}$이었다. 저분자량 키토산 올리고당은 폐암 세포주인 A549, 방광암 세포주인 J82, 대장암 세포주인 SNU-C4, 위암 세포주인 SNU-1, 유방암 세포주인 ZR75-1 등과 같은 사람의 종양세포주에 대한 in vitro 항종양성을 나타내었다. 종양세포주에 대한 저분자량 키토산 올리고당의 $IC_{50}$값은 A549, J82, SNU-C4, SNU-1, ZR75-1 세포주의 경우에 각각 $477.42{\mu}/m{\ell}$, $480.40{\mu}g/m{\ell}$, $436.84{\mu}g/m{\ell}$, $373.55{\mu}g/m{\ell}$, and $539.95{\mu}/m{\ell}$이었다.

• Journal of Pharmaceutical Investigation
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• 제28권3호
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• pp.151-158
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• 1998

The inhibition rate of bacteria growth per molecular weight was higher according as the molecular weight increased, the rate was the highest at the molecular weight 200,000. Microcapsule of ionized calcium was able to be produced by molecular weight 15,000, 30,000, 50,000 and 200,000 of chitosan which was dried for 48 hours after melting it in 2% of acetic acid, adding ionized calcium and controlling pH 1.2. The size of ionized calcium microcapsule was between 200 and $300\;{\mu}m$, the solvency, concentration and the content showed big difference by the molecular weight of chitosan. The inhibition rate of bacteria growth of microcapsule designated high in Gram positive, which was high in S. aureus, S. epidermidis and Bacillus subtilis, low in S. mutans, high in C. albicans in fungi, low in A. niger. The inhibition rate of bacteria growth of chitosan was comparatively high in Gram positive, low in S. mutans and it showed high numerical value in C. albicans of fungi. The rate recorded good result at molecular weight 200,000 relatively, there was no difference according to the molecular weight. The inhibition rate of bacteria growth according to the concentration of the microcapsule increased differently between $1.000{\sim}10,000\;{\mu}g/ml$, it showed antibacterial activity close to the inhibition rate of growth of chitosan rather than ionized calcium. The minimum inhibitory concentration marked the highest in the mixture of chitosan and ionized calcium for all kind of bacteria generally, there was a little difference between yeast and fungi.

• Journal of the Korean Wood Science and Technology
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• 제23권1호
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• pp.13-20
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• 1995

This study was carried out to investigate the characterization of lignins from waste liquors in SP, KP, ASAM, and AS from Pinus densiflora, Quercus mongolica, and Betula ermanii. Spectroscopic study was applied to examine the lignins separated from different pulping process. Lignin contents in waste liqours increased in order of AS, ASAM, KP, and SP. UV spectra of three types of lignin except AS lignin showed similar pattern. IR spectra of AS lignin showed strong C=O absorptions in the range from 1730 to 1750$cm^{-1}$, where as those of KP, SP, and ASAM showed weak stretch in this region. NMR spectra of AS lignin showed strong characteristic chemical shifts of acetoxyl groups of acetylated aliphatic and aromatic hydroxyl groups at 2.0~2.5 ppm. Molecular weight of ASAM lignin from Pinus densiflora determined and found number average molecular weight 1,199, weight average molecular weight 5,458. z average molecular weight 17,242, and viscosity average molecular weight 5,457. It is considered from the results based on spectroscopic study of lignin that waste liquors (in SP, KP, ASAM and AS) from Pinus densiflora, Quercus mongolica, and Betula ermanii can be used for lignin utilization.

• 한국가구학회지
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• 제12권2호
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• pp.29-38
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• 2001

This study was carried out to develope a new process of flattening bamboo pieces(3 months old) by two steps of utilizing microwave oven and hot press. Internode bamboo pieces were impregnated with low molecular weight phenol formaldehyde resin (PF) under vacuum of 76 cmHg, heated in a household microwave oven in 1 minute, pressed on the temperature of $145^{\circ}C$ by the hot press for 10 minute, and then cooled by the cold press in their flattened form. The physical and mechanical . Properties of compressed flattened bamboo were as follows: 1) PF1(Mw:427) and PF2(Mw:246) sol. met the success of flattening of internode bamboo pieces in both of P. bambusoides and P. nigra var. PF2 showed the more plasticity to flatten the bamboo than PFI. The PF2 sol. with low molecular weight(Mw:246) gave the more weight gain than that of PF1 in the equal concentration. PF1 of 5% (NVC) and PF2 of 10% (NVC) sol. gave the best result for physical and mechanical properties and from a economical view point. 2) The PFI of 5% (NVC) sol. with low molecular weight decreased the water absorption of 62-63% and increased the bending strength (MaR) of 80-90%, compression strength of 43-54%. 3) The PF2 of 10% (NVC) sol. with low molecular weight decreased the water absorption of 56-57% and increased the bending strength (MaR) of 64-86%, compression strength of 39-63%.

• 펄프종이기술
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• 제44권5호
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• pp.21-31
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• 2012

In this study, we modified the surface of ground calcium carbonate (GCC) with polyelectrolytes with different molecular weight using Layer-by-Layer (LbL) multilayering technique and investigated its effect on the paper properties. Polydiallydimethylammonium chloride (poly-DADMAC) and poly sodium 4-styrene sulfonate (PSS) which have different molecular weights were used for LbL multilayering. Zeta potential and particle size of the LbL modified GCC were measured. After preparation of handsheets, their structural and mechanical properties were evaluated. The zeta potential and average particle size of the modified GCC were affected by the molecular weight of anionic polyelectrolyte (PSS). The zeta potential was higher and the particle size was smaller when GCC was treated by PSS with high molecular weight compared to the case with low molecular weight of PSS. The tensile and internal bond strength of the handsheets was increased with an increase in the number of layers on GCC particles, but the molecular weight of polyelectrolyte did not significantly affect the paper strength.

• Journal of Microbiology
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• 제34권3호
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• pp.279-283
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• 1996

The weight average molecular weight of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) synthesized by Alcaligenes sp. SH-69 was altered between $3.2$\times$10^5$ and $1.1$\times$10^6$ depending upon various culture conditions. It appeared that culture conditions favorable for the efficient production of copolyesters promoted the formation of higher molecular weight copolyesters. Polydispersity indices of isolated copolyesters were in the range of 1.5 to 2.5.

• 분석과학
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• 제8권4호
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• pp.465-468
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• 1995

Matrix assisted laser desorption ionization in mass spectrometry is a fast and accurate method to determine the molecular weight of natural and synthetic polymers. Unknown peptides such as elastase inhibitor and $\small{D}$-hydantoinase were analyzed using sinapinic acid as matrix and their molecular weights were compared with the results from protein sequencer and gel filtration chomatography, respectively. Synthetic polymers such as polyethyleneglycol, polypropyleneglycol, polydimethylsiloxane, and polystyrene were analyzed using matrices such as 2,5-dihydroxybenzoic acid, 4-hdroxyazobenzenecarboxylic acid, and 2-nitrophenyl octyl ether. Average molecular weights of polystyrene were compared with molecular weights by gel permeation chromatography.

• Bulletin of the Korean Chemical Society
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• 제20권11호
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• pp.1323-1328
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• 1999

Interdiffusion between two partially miscible polymers of similar chemical structures with different molecular weights is characterized theoretically by using the reptation model for the interdiffusion. This model provides more reliable results than the early Rouse model for same molecular weights, compared with the experiments. Furthermore, by introducing the molecular weight ratio R into the reptation model, we can see the dynamic effect of molecular weight on the diffusion behaviors of the asymmetric system. Near the critical point the diffusion behaviors of asymmetric binary polymer mixtures are well characterized by the interfacial width W(t), the mass transport M(t) for the different values of the Flory Χ parameter and different molecular weight ratios ofpolymers of the diffusion couple. These two quantities and composition profiles by this model give betteragreement with experiments.

• 한국식품저장유통학회지
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• 제15권6호
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• pp.903-908
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• 2008

본 연구는 두유와 전두유의 효소적 가수분해에 따른 단백질의 변화를 조사하였다. 총 유리아미노산 함량을 조사한 결과 두유(SM)과 전두유(WSM)에 비해서 저분자 두유(LSM)와 저분자 전두유(LWSM)에서 높게 나타났다. 필수아미노산 함량은 SM과 LSM에서 비슷하였으나 LWSM은 WSM보다 높게 나타났다. SDS-PAGE 전기영동 패턴 분석결과 SM과 WSM에서는 $33{\sim}72\;kDa$의 고분자가 존재하였으나 LSM와 LWSM에서는 17 kDa 이하의 저분자 단백질만 나타났다. 또한 이차원 전기영동한 결과 SM과 LSM에서의 고분자 단백질 spot이 WSM와 LWSM에서는 다양한 크기의 저분자 단백질 spot으로 변환되어 효소가수분해에 의해 고분자 단백질이 저분자화 되는 것으로 나타났으며, 향후 단백질 spot의 분리 및 특성에 관한 연구가 필요하다.

• 폴리머
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• 제31권6호
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• pp.555-561
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• 2007

다양한 분자량을 가진 저분자량 수용성 키토산을 얻기 위해 젖산염이 결합되어 있는 키토산 올리고당을 한외여과막 장치를 이용하여 분리하였고, 새로운 염 제거법으로 유리 아민기를 가진 LMWSC를 제조하였다. 젖산염이 제거된 LMWSC의 특성과 탈아세틸화도가 적외선 분광기(Infrared spectroscopy, IR) 및 핵자기공명장치($^1H-Nuclear$ Magnetic Resonance, $^1H-NMR$)에 의해 확인되었다. 분자량을 나타내는 다분산지수(PDI)는 $1.278{\sim}1.499$로 비교적 좁은 분자량분포를 나타내었다. 유전자 전달체로서의 가능성을 확인하기 위하여, 성공적으로 분자량에 따라 분리된 키토산 올리고당과 염이 제거된 LMWSC의 유전자 전이효율이 293T cell을 이용하여 확인하였다. 또한 유전자 전이효율을 향상시키기 위해 제조된 LMWSC 유도체가 Balb/C mice를 이용하여 평가되었다.