• 멤브레인
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• 제22권5호
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• pp.352-358
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• 2012

본 연구는 pressure retarded osmosis (PRO) 분리막의 구조적 특성이 미치는 영향에 대하여 수행되었다. 이를 위해, 유사 분자구조를 가지며 자유부피는 차이가 나는 BPS-XX, BisA-XX가 선택되었다. BPS-XX와 BisA-XX는 축중합 반응을 통해 합성되었으며, 또한 더 세분화된 결과를 위해서 20~60 mol.%로 술폰화되었다. 자유부피의 변화에 따른 분리막의 특성을 입증하기 위해서 몇 가지 특성평가가 진행되었다. 연구 결과에서 동일 분자구조에서 자유부피가 증가하면 막의 투과도가 증가하였고, 선택도는 감소하였다. 본 연구의 투과도-선택도 결과에서, 분자의 기본 구조와 자유부피 조절에 따라서, 고 투과도와 선택도를 가진 막을 제조 가능함을 알 수 있었다.

• 한국잠사학회:학술대회논문집
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• 한국잠사학회 2003년도 제46회 춘계 학술연구 발표회
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• pp.76-76
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• 2003

Here we report an antifungal peptide isolation from G. mellonella larvae. The peptide shows a high degree of sequence homology to an insect defensin, named heliomicin, first reported in Lepidoptera. The peptide was purified by a three-step procedure consisting of acid extraction, gel permeation chromatography and reversed-phase HPLC. First the N-terminal amino acid sequence of the purified peptide was determined by automated Edman degradation. (omitted)

• 마이크로전자및패키징학회지
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• 제11권4호
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• pp.69-73
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• 2004

A series of $H_3PO_4$-doped composite membranes based on poly(vinyl alcohol)(PVA) and silica have been prepared by sol-gel process. The proton conductivity, as well as properties of swelling, methanol permeation, was measured in this study. The proton conductivity increased with the molar ratio of $H_3PO_4$ to silica. With the silica content increasing, swelling degree decreased and methanol permeability showed a slight increase. It suggested that the former was mainly determined by hydrophilicity of the membrane, while the latter was dominated by the interconnectivity of matrix. According to the value of on, the optimal conformations of these composite membranes were 60, 70, 80 wt.$\%$ of PS-x in membranes, where x were 1.5, 1.0, and 0.5, respectively. These composite membranes were thermal stability up to $200^{\circ}C$.

• 한국막학회:학술대회논문집
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• 한국막학회 1998년도 춘계 총회 및 학술발표회
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• pp.1-6
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• 1998

To change permselectivity between anions through the anion exchange membrane in electrodialysis, the various modified anion exchange membranes were prepared: highly crosslinked anion exchange membranes, anion exchange membranes having benzyl trialkylammonium groups with different carbon number of alkyl chain as anion exchange groups and anion exchange membranes having pyridinium groups with a hydrophilic or hydrophobic substituent at a different position as anion exchange groups. It became clear from the evaluation of these membranes that the degree of the hydrophilicity of the anion exchange membranes greatly affects the permselectivity between two artions. To increase the hydrophiticity of the anion exchange membranes further, electrodialysis was carried out in the presence of ethylene glycols and the permeation of strongly hydrated anions increased and that of less-hydrated anions decreased. It became clear that the change in the permselectivity between two artions is due to the change in the affinity of anions to the membranes, not the change in mobility ratio of the anions in the membranes phase.

• Biomolecules & Therapeutics
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• 제17권3호
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• pp.241-248
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• 2009

The purpose of this study was to evaluate the effect of methylsulfonylmethane (MSM) on hair growth promotion of magnesium ascorbyl phosphate (MAP) for the treatment of alopecia. Aqueous solutions of MAP 7.5% with or without MSM 1%, 5% or 10% were prepared and applied onto the depilated back skin of the male mice once a day for 20 days. The degree of hair growth was evaluated by visual scoring using hair growth quantification scale (0-5, 0 being initial state and 5 being complete hair growth). In vitro transdermal penetration and intradermal retention studies of MAP were performed with Franz diffusion cell using hairless mice skin. Hair growth in the group treated with the aqueous solution containing MAP 7.5% and MSM 10% was comparable to or better than the result in the group treated with minoxidil 5% solution. Hair growth promotion of MAP was dose-dependently increased by the presence of MSM used in combination with MAP 7.5% solution. The in vitro transdermal penetration of the MAP was decreased in proportion to the concentration of MSM. However, intradermal retention of MAP was profoundly and dose-proportionally increased as a function of MSM concentration, reaching 802 ${\mu}g/cm^2$ in the presence of MSM 10% (200-fold increase). The effect of MSM on hair growth promotion of MAP was dose-proportional to the concentration of MSM due to the enhanced intradermal retention of MAP in the presence of MSM. Therefore, topical application of MAP together with MSM appears to be useful for the treatment of alopecia.

• 한국막학회:학술대회논문집
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• 한국막학회 2004년도 추계 총회 및 학술발표회
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• pp.142-145
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• 2004

Anion-exchange porous hollow-fiber membranes with a thickness of about 1.2 mm and a pore size of about $0.30{\mu}m$ were used as a supporting matrix to immobilize cycloisomaltooligosaccharide glucanotransferase (CITase). CITase was immobilized to the membrane via anion-exchange adsorption and by subsequent enzymatic cross-linking with transglutaminase, the amount of which ranged from 3 to 110 mg per g of the membrane. The degree of enzyme multilayer binding was equivalent to 0.3 to 9.8. Dextran, as the substrate, was converted into seven- to nine-glucose-membered cycloisomaltooligosaccharides (CI-7, -8, and -9) at a maxi mum yield of $28\%$ in weight at a space velocity of 10 per hour during the permeation of $2.0(w/w)\%$ dextran solution across the CITase-immobilized porous hollow-fiber membrane.

• Bulletin of the Korean Chemical Society
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• 제35권2호
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• pp.501-504
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• 2014

A thermoresponsive polymer, poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA), was successfully synthesized by atom transfer radical polymerization (ATRP). Different amounts of 1,3-propanesultone were used as quaternization agent to transit the PDMAEMA into partially modified poly(zwitterions), resulting in p[DMAEMA-co-3-dimethyl(methacryloyloxyethyl)ammonium propanesulfonate] (PDMAEMA-co-PDMAPS). Molecular weight, molecular weight distribution, and degree of quarternization were determined by gel permeation chromatography (GPC) and 1H NMR spectroscopy. The transmission spectra of the 1.0 wt % aqueous solutions of the resulting polymers at 650 nm were measured as a function of temperature. Results showed that the lower critical solution temperature (LCST) and the upper critical solution temperature (UCST) could be easily controlled by the different composition of dimethylamino and zwitterion groups. The effect of partial quaternization on thermoresponsive properties was also studied by dynamic light scattering (DLS) with the same aqueous concentration (1.0 wt %) as employed for turbidimetry studies. The LCST and UCST values measured by DLS correlated well with those determined by turbidimetry.

• 보존과학회지
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• 제25권2호
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• pp.155-160
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• 2009

유구의 지속성과 안정성을 높이기 위하여, 저점도 Epoxy인 SE-101의 토양의 입자 크기와 수분 함량에 따른 침투성과 전단 강도를 측정하였으며, 이 결과들을 이용하여 SE-101의 사용법을 최적화하고자 하였다. 점도 데이터로부터 충분히 예상되었듯이, 입자의 크기가 증가할수록 침투도는 증가하였으나, 전단 강도는 감소하였으며 특히, 고분자의 불균일한 경화 속도와 내부 무기 첨가제에 따라서 침투도의 편차가 심하여 질 수 있음을 알 수 있었다. 토양 내의 수분 함량이 증가할수록, 침투도와 전단 강도의 편차가 매우 심하여져서 동일 시편 내에서도 매우 취약한 부분이 생성되고, 유구 이전 중의 파손 현상 발생도 예측할 수 있어 이전재의 침투 깊이의 50% 이상은 건조된 상태에서 사용하는 것이 필요한 것으로 보인다.

• 한국식품과학회지
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• 제26권6호
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• pp.819-823
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• 1994

쌀전분을 이용한 지방대체소제의 개발을 목적으로 ${\alpha}-amylase$를 이용하여 가수분해도가 낮은 rice maltodex-trin을 제조하고 이의 일반적인 특성과 유동특성을 검토하였다. 쌀전분을 고온에서 호화시킨 후 내열성 ${\alpha}-amylase$로 가수분해 시킨 rice maltodextrin의 평균 중합도는 D.E. 값이 3,4,5,6일 때 각각 72.8, 64.7, 56.3, 48.7이었으며, 상당히 한정된 중합도 분포를 나타내었다. D.E. $3{\sim}6$의 maltodextrin의 찬물에 대한 용해도는 D.E. 값의 중가에 따라 473%에서 71.5%로 현저하제 증가되었다. Rice maltodextrin 8%(w/v) 용액은 의가소성 유체거동을 보였으며, D.E. 값이 증가함에 따라 유동거동지수 n가 강소하였구 곁보기 점도는 $2{\sim}7\;mPa{\cdot}s$ 범위의 값을 가졌다.

• 한국미생물·생명공학회지
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• 제23권4호
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• pp.411-415
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• 1995

The dextranase (EC 3.2.1.11) produced by Aspergillus ustus GR-98 was purified by the following sequential methods; salting-out and dialysis, gel filtration on BIO-GEL P-100, ion exchange chromatography on DEAH-cellulose, affinity chromatography on hydroxyapatite, and preparative electrophoresis. Three active fractions, dextranases 1, 11 and 111, were isolated in electrophoretically pure states, and specific activities of the dextranases were 1,276, 1,154 and 1,125 units/mg, the degrees of yield were 9.0, 3.6 and 2.2%, having 145, 131.1 and 127.8 times as those of culture filtrate in degree of purification, respectively. The enzyme purity was confirmed by the PAGE, SDS-PAGE and get permeation-HPLC.