• Journal of Nutrition and Health
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• 제28권8호
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• pp.727-736
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• 1995

The hypoglycemic effect of Polygonatum odoratum var. Pluriflorum Ohwi was investigated after extracted with methanol. The methanol extract was fractionated into 4 layers ; hexane, chloroform, butanol and aqueous. Fifty male Sprague-Dawley rats(200-300g) were induced diabetes mellitus by the streptozotocin injection(45mg/kg B.W) into the tail vein and were divided into 5 groups ; diabetic control and 4 experimental groups. All groups of the rats were fed on a AIN-76 diet, and the 4 experimental groups were orally administered with each fraction(500mg/kg B.W) for 12 days and the diabetic control group was orally administered CMC. The body weight gain was monitered and the blood levels of glucose and cholesterol were measured. Levels of protein, triglyceride, and free fatty acid in plasma were analysed. The contents of protein, triglyceride and glycogen in liver and of protein and glycogen in muscle were also determined. The body weight gain was shown significantly higher in the H2O fraction group than that in the diabetic control group and the heart weight was greater in the CHCl3 group. The extents of blood glucose decrement were greater in the BuOH and H2O groups than that in the control group. The urinary glucose excretion was shown relatively small amount in the BuOH and H2O groups. The plasma cholesterol and protein levels were not influenced by these four fractions in diabetic rats. The liver glycogen level was significantly higher in the BuOH group. The results suggest that the orally administered BuOH and H2O fraction of Polygonatum odoratum var. Pluriflorum Ohwi exhibited hypoglycemic effect in streptozotocin induced diabetic rats.

• Korea-Australia Rheology Journal
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• 제14권4호
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• pp.189-201
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• 2002

The interaction between hydrophobically modified hydroxyethyl cellulose (hmHEC), containing approximately 1 wt% side-alkyl chains of $C_{16}$, and an anionic sodium dodecyl sulphate (SDS) surfactant was investigated. For a semi-dilute solution of 0.5 wt% hmHEC, the previously observed behaviour of a maximum in solution viscosity at intermediate SDS concentrations, followed by a drop at higher SDS concentrations, until above the cmc of surfactant when the solution resembles that of the unsubstituted polymer, was confirmed. Additionally, a two-phase region containing a hydrogel phase and a water-like supernatant was found at low SDS concentrations up to 0.2 wt%, a concentration which is akin to the critical association concentration, cac, of SDS in the presence of hmHEC. Above this concentration, SDS molecules bind strongly to form mixed micellar aggregates with the polymer alkyl side-chains, thus strengthening the network junctions, resulting in the observed increase in viscosity and elastic modulus of the solution. The shear behaviour of this polymer-surfactant complex during steady and step stress experiments was examined In great detail. Between SDS concentrations of 0.2 and 0.25 wt%, the shear viscosity of the hmHEC-polymer complex network undergoes shear-induced thickening, followed by a two-stage shear-induced fracture or break-up of the network. The thickening is thought to be due to structural rearrangement, causing the network of flexible polymers to expand, enabling some polymer hydrophobic groups to be converted from intra- to inter-chain associations. At higher applied stress, a partial local break-up of the network occurs, while at even higher stress, above the critical or network yield stress, a complete fracture of the network into small microgel-like units, Is believed to occur. This second network rupture is progressive with time of shear and no steady state in viscosity was observed even after 300 s. The structure which was reformed after the cessation of shear is found to be significantly different from the original state.

• 한국의류학회지
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• 제13권1호
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• pp.89-97
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• 1989

Graft polymerization of MMA onto cotton fiber was carried out in two ways, two step graft polymerization and one step emulsion graft polymerization, using tetravalent cerium ion as an initiator. At two step graft polymerization, the first step was the pretreatment of cotton fiber with an aqueous initiator solution and the second was the grafting pretreated cotton fiber in the monomer solution. In case of one step emulsion graft polymerization, MMA was emulsified with SLS in initiator solution. Under the various graft polymerization conditions, graft yield, graft efficiency and from the Arrhenius plot the apparent activation energy were compared. The results of this study were as follows: 1. Graft yield and graft efficiency of emulsion graft polymerization were higher than those of two step graft polymerization. 2. In case of two step graft polymerization, graft yield was affected by the pretreatment time of cotton fiber with an aqueous initiator solution. And graft yield of emulsion graft polymerization was increased with the concentration of emulsifier below cmc of SLS and was decreased thereafter. 3. Elevation of temperature resulted increase in graft yield for both grafting methods. The apparent activation energy of emulsion graft pelymerzation was lower than that of two step graft polymerization. 4. Increased reaction time increased in graft yield, but decreased in graft efficiency. 5. Moisture regain of grafted cotton was decreased with graft yield.

• 한국의류학회지
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• 제18권5호
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• pp.661-673
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• 1994

We have gathered a fatty acid to recycle the waste oil of food manufacturing process, and then made a soap from the waste oil by alkali saponification. Effects of the washing elements such as the concentration of the soap, temperature and time were evaluated to find out the optimum washing conditions, and results are as follows. 1. We could find soaps made from the soybean oil (A), corn oil (B), rape seed salad oil (C), cotton seed oil (D) and a soap consisting of the each oil 25% respectively (I) had the lowest surface tension at the concentration of 0.225% -0.25%. Compared with the single fatty-acid soap, the multi-component soap I showed the lower surface tension at the cmc. 2. All the samples of A-I showed the lowest contact angle for the solid material at the concentration of 0.25%. The multi-component soap of I showed higher contact angle than the single.component soaps of A, B, C and D. 3. The soap G, made from the waste oil, show lower surface tension than 5, made from the complex raw fats of the eatable fatty oil acid and H, commercial soap. 4. The washing efficiency depends on the washing time. Especially the 25-minute was found to be the optimum washing time. 5. The highest washing efficiency was found at the 0.25% cont. reagardless of the washing temperature. At 0.15% concentration level the washing efficiency reduces as washing tem- perature increases. At 0.3% concentration level the highest washing efficiency was found between $50^{\circ}$-$60^{\circ}$. 6. The soap made from the waste oil showed the highest washing efficiency in terms of concentration, temperature, and time. 7. The soap made from the waste oil showed the similiar concentration of hydrogen ion to the synthetic detergent. 8. The hand value of the fabric washed by the soap made from the waste oil was a little lower value than those washed by the synthetic detergent.

• Journal of Microbiology and Biotechnology
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• 제16권7호
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• pp.1132-1138
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• 2006

Three types of xylanases (EC 3.2.1.8) were detected in the strain Aspergillus niger A-25, one of which, designated as XynIII, also displayed ${\beta}-(l,3-1,4)-glucanase$ (EC 3.2.1.73) activity, as determined by a zymogram analysis. XynIII was purified by ultrafiltration and ion-exchange chromatography methods. Its apparent molecular weight was about 27.9 kDa, as estimated by SDS-PAGE. The purified XynIII could hydrolyze birchwood xylan, oat spelt xylan, lichenin, and barley ${\beta}-glucan$, but not CMC, avicel cellulose, or soluble starch under the assay conditions in this study. The xylanase and ${\beta}-(l,3-1,4)-glucanase$ activities of XynIII both had a similar optimal pH and pH stability, as well as a similar optimal temperature and temperature stability. Moreover, the effects of metal ions on the two enzymatic activities were also similar. The overall hydrolytic rates of XynIII in different mixtures of xylan and lichenin coincided with those calculated using the Michaelis-Menten model when assuming the two substrates were competing for the same active site in the enzyme. Accordingly, the results indicated that XynIII is a novel bifunctional enzyme and its xylanase and ${\beta}-(l,3-1,4)-glucanase$ activities are catalyzed by the same active center.

• 한국컴퓨터산업학회논문지
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• 제5권3호
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• pp.383-392
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• 2004

전자게시판은 비동기적으로 생각을 교환하고 정보를 공유하는 적절한 매체로써 널리 인식되어왔다. 게시판의 의사소통 능력은 협력학습을 위한 도구로 사용하는 주된 이유이다. 최근 이 분야의 연구자들은 게시판의 교육적 활용에 대한 연구결과를 다수 보고하고 있다. 이 논문에서는 게시판에서의 의사소통 활동을 측정함으로써 토의 참여자들의 복잡한 토의 행동을 정량적으로 이해할 수 있는 분석적 방법을 제안한다 토의 집단이나 개인들의 토의 행동을 기술하기 위한 특성 벡터를 제안한다. 이 특성 벡터는 토의 집단과 개인에 대한 특성화와 비교를 편리하게 할 수 있도록 한다. 상호작용 활동을 표현하는 상호작용 모델은 토의 그룹과 개인에 대한 상호작용 정도를 시각적으로 나타낸 준다. 또한, 시간에 따른 토의 활동을 분석하기 위해 시간 종속적인 측정을 탐구한다. 전자 게시판을 사용한 웹 기반 토의 프로젝트를 통하여 제안한 측정이 어떻게 이루어지는지, 또 특성 벡터와 상호작용 모델이 어떻게 구축되고 사용되는지를 실험을 통하여 보여준다.

• 한국응용과학기술학회지
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• 제35권3호
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• pp.579-586
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• 2018

본 연구에서는 지방 알코올을 이용하여 탄소 길이에 따른 술폰산계 음이온 계면활성제를 합성하였으며, 합성한 계면활성제들의 구조를 FT-IR과 $^1H$ NMR 분석을 통하여 확인하였다. 음이온 계면활성제의 임계미셀농도(critical micelle concentration: cmc)는 $10^{-5}{\sim}10^{-3}mol/L$이며, 임계미셀농도에서의 표면장력 값은 26~32 mN/m이었다. 합성한 술폰산계 계면활성제의 분자당 최소 영역값은 $1.68{\sim}1.30nm^2$이다. 음이온 계면활성제의 분자당 최소 영역이 감소하였다. 합성한 계면활성제의 물성은 임계 미셀농도, 기포력, 유화력, 접촉각을 측정하였다.

• Journal of Microbiology and Biotechnology
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• 제16권5호
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• pp.716-723
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• 2006

A biosurfactant-producing bacterial strain was selected from oil-contaminated soil because of its ability to degrade crude oil and tributyrin $(C_{4:0})$. The strain was identified as Bacillus subtilis A8-8 based on its morphological, biochemical, and physiological characteristics. When B. subtilis A8-8 was grown with crude oil as the sole carbon source, the biosurfactant from the strain emulsified crude oil, vegetable oil, and hydrocarbons. Soybean oil was the optimum substrate for the emulsifying activity and emulsion stability of the biosurfactant, both of which were superior to those of several commercially available surfactants. The biosurfactant was purified by a procedure including HCl precipitation, methanol treatment, and silica-gel chromatography. The partially purified biosurfactant was analyzed by TLC (thin-layer chromatography), SDS-PAGE, and HPLC and it reduced the surface tension of water from 72 mN/m to 26 mN/m at a concentration of 30 mg/l. Therefore, the purified lipopeptide biosurfactant has strong properties as an emulsifying agent and acts as an emulsion-stabilizing agent.

• 한국응용과학기술학회지
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• 제11권1호
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• pp.79-85
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• 1994

All the activities and physical properties including surface tension' foaming power, foam stability, emulsifying power, dispersion effect of 3-(N, N-dimethyl N-alkylammonio)-2-hydroxyY-1-propane sulfonate (HSB)류와 3-CN-alkylamidopropyl-N,N-dimethylamm-onjo)-2-hydroxy-1-propane sulfonate (APSB) aquous solution were measured and critical micelle concentration was evaluated. Their cmc of hydroxy sulfobetaine derivatives evaluated by the surface tension method was $1.0{\times}10^{-3}{\sim}1.0{\times}10^{-4}$ mol/l, and surface tension of the aquous solution was decreased to $27{\sim}38dyne/cm$. The experimental results for foaming power, foam stability, emulsifying power in liquid paraffin showed a good surface active properties, especially, dispersion effect in ferric oxide exhibited some efficient surface active properties, and then it would be expected to application as detergent and dispersion agent.

• Journal of Microbiology and Biotechnology
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• 제23권11호
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• pp.1598-1609
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• 2013

Organochlorine pesticide residues continue to remain as a major environmental threat worldwide. Lindane is an organochlorine pesticide widely used as an acaricide in medicine and agriculture. In the present study, a new lindane-degrading yeast strain, Pseudozyma VITJzN01, was identified as a copious producer of glycolipid biosurfactant. The glycolipid structure and type were elucidated by FTIR, NMR spectroscopy, and GC-MS analysis. The surface activity and stability of the glycolipid was analyzed. The glycolipids, characterized as mannosylerythritol lipids (MELs), exhibited excellent surface active properties and the surface tension of water was reduced to 29 mN/m. The glycolipid was stable over a wide range of pH, temperature, and salinity, showing a very low CMC of 25 mg/l. Bio-microemulsion of olive oil-in-water (O/W) was prepared using the purified biosurfactant without addition of any synthetic cosurfactants, for lindane solubilization and enhanced degradation assay in liquid and soil slurry. The O/W bio-microemulsions enhanced the solubility of lindane up to 40-folds. Degradation of lindane (700 mg/l) by VITJzN01 in liquid medium amended with bio-microemulsions was found to be enhanced by 36% in 2 days, compared with degradation in 12 days in the absence of bio-microemulsions. Lindane-spiked soil slurry incubated with bio-microemulsions also showed 20-40% enhanced degradation compared with the treatment with glycolipids or yeast alone. This is the first report on lindane degradation by Pseudozyma sp., and application of bio-microemulsions for enhanced lindane degradation. MEL-stabilized bio-microemulsions can serve as a potential tool for enhanced remediation of diverse lindane-contaminated environments.