• Polymer(Korea)
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• v.30 no.2
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• pp.112-117
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• 2006

To improve the type error of osmotic tablet which is one of the drug delivery system, osmotic granule could be manufactured by fluidized bed coating. It has drug layer containing different amount of osmogant and is coated with membrane including different types of binder. We confirmed that the morphology of osmotic granule was different at each coating step. The more mont of osmotic agent, the faster drug release was observed due to increasing the driving force for drug release from osmotic granule. And drug release from osmotic granule coated with membrane using different types of binder was differed by solubility of binders to water. The formation of pore in membrane was confirmed by SEM and DSC Membrane using water soluble binder released more amount of drug. From these results, we assured that difference of osmotic pressure between the inside and the outside of granule and porosity of membrane have an effect on drug release from osmotic granule.

• Korean Journal of Plant Resources
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• v.24 no.1
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• pp.1-9
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• 2011

In the present study, the anti-oxidative properties of 80% ethanol extracts from 140 kinds of natural plants were investigated. Persicaria perfoliata had the highest anti-oxidative relative potency(VitaminE, $ORAC_{PE}$=1.0), followed by Sorbaria sorbifolia var. stellipila, Rosa multiflora, Lysimachia vulgaris var. davurica, Quercus aliena, Quercus mongolica and Lespedeza bicolor ($ORAC_{PE}$ ${\geq}$ 1.50). Among them, the anti-oxidative activity values of the n-hexane, $CH_2Cl_2$, EtOAc, n-BuOH, and water fractions of the 80% EtOH extracts of P. perfoliata and S. sorbifolia in the ORAC assay system were $1.13{\pm}0.002$, $1.10{\pm}0.004$, $3.67{\pm}0.232$, $1.62{\pm}0.049$ and $1.05{\pm}0.003$; $1.02{\pm}0.007$, $1.00{\pm}0.016$, $2.94{\pm}0.130$, $1.80{\pm}0.019$ and $1.04{\pm}0.012$, respectively, with marked anti-oxidative activity in the ethyl acetate fraction from selected the 2 plant extracts.

• Korean Journal of Plant Resources
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• v.24 no.1
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• pp.61-68
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• 2011

Loperamide-induced constipation reduced gastric emptying, small-intestinal and colonic motility, and these effects were prevented by Actindia chinensis(Gold Kiwi Fruit, GKF). In this study, the effects of Actindia chinensis on constipated male Sprague-Dawley rats induced by loperamide(2 mg/kg, s.c.,5 days) were investigated. Rats were randomly assigned to the normal control rats(regular diet), constipated rats(regular diet plus loperamide), constipated rats treated with 2.5% GKF(regular diet supplemented with 2.5% GKF plus loperamide), constipated rats treated with 5% GKF (regular diet supplemented with 5% GKF plus loperamide). There was less fecal excretion and lower fecal water content in loperamide-treated rats than in control rats. Oral administration of GKF blocked the decrease of fecal excretion and fecal water content in the loperamide-treated rats. Mucus production of crypt cell and mucus contents at fecal and mucosa surface were reduced by loperamide-treated rat. But colonic crypt cell contained increased mucin in the GKF treated group and mucus layer stained with alcian blue was significantly thicker in GKF treated rats compared with in loperamide-treated rats. In isolated rat ileum, loperamide produced inhibition of ileal motility. Pretreatment with methanolic extracts of GKF in isolated rat ileum prevented inhibition by loperamide. These findings indicated that the GKF was effective for alleviation of inhibition of colonic peristalsis by loperamide and that GKF might be of value in the prevention of constipation.

• Clean Technology
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• v.8 no.3
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• pp.119-128
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• 2002

In the present study the membrane filtration characteristics of a commercially available synthetic water-based cutting oil through two kinds of ultrafiltration membranes (HF1-45-CM50 and HF1-43-CM100) with molecular weight cut-offs of 50,000 and 100,000, respectively, have been investigated in detail. Among these membranes, the hydrophilic one (HF1-45-CM50) was found to show a satisfactory result for both the permeate flux and the permeability of oil components, whereas the permeate flux obtained with the hydrophobic membrane (HF1-43-CM100) appears to be significantly low, indicating that synthetic cutting oil was easily wetted on the hydrophobic membrane surface and induced more membrane fouling. The effect of material characteristics of the membrane on the filtration characteristics was found to be much more significant compared with the mean pore size of the membrane. Backflushing by nitrogen gas was applied to reduce the formation of a gel layer and membrane fouling. With the hydrophilic membrane, the backflushing was found to increase the permeate flux, whereas the backflushing resulted in a decrease in flux for the hydrophobic membrane. The flux recovery was observed to be highest when the membranes fouled with waste synthetic cutting oil were immersed into a cleaning solution for more than 72 hours and then backflushed by nitrogen gas.

• Korean Journal of Materials Research
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• v.11 no.5
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• pp.405-412
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• 2001

Corrosion tests were carried out in $360^{\circ}C$ water and $360^{\circ}C$ 70ppm LiOH solution to investigate the corrosion behavior of new zirconium alloys (Zr-0.4Nb-0.8Sn-xFeCrMn, Zr-0.2Nb-1.1Sn-xFeCrMn, Zr-1.0Nb-xFeCu). Microstructures of tested alloys were analyzed by optical microscope and TEM. The cross-sectional surface and crystalline structure of the oxide layer were analyzed by SEM and XRD. From the results of corrosion test, all the alloys showed higher corrosion rates in $360^{\circ}C$ 70ppm LiOH aqueous solution thats in $360^{\circ}C$ water. Especially, high Nb-containing alloy exhibited the acceleration of corrosion rate in LiOH solution. The low Nb- and Sn-added alloys showed better corrosion resistance than the Sn- free high Nb alloy. from the effect of final annealing on the corrosion, it was observed that the partially recrystallized alloys showed better corrosion resistance than fully recrystallized alloys. This would be related to the size and distribution of the second phase particles.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.5
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• pp.633-642
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• 1994

Distribution of ichthyoplankton in the adjacent waters to Kori were surveyed during the period from April, 1991 to January, 1992. The dominant fish eggs included the eggs of Engraulis japonica, Maurolicus muelleri, Callionymus spp. and others. The eggs of Engrualis japonica and Maurolicus muelleri were $79.52\%$ and $1.86\%$ of the total eggs abundance, respectively. A total of 15 taxa of fish larvae were found. The dominant species was Engraulis japonica accounting for $52.39\%$ of the total larvae and followed by Callionymidae fish($29.36\%$). Other major species were Stephanolepis cirrhifer($6.30\%$), Sebastes schlegeli($3.16\%$), Ammodytes personatus($1.33\%$) and Girella punctata($1.70\%$). These 6 taxa constituted $94.30\%$ of the total larvae collected. In this area, distributions of warm water had a great influence on larvae and juvenile distribution which usually is along the coast and the other places where there layer water movements since, upwelling in the open sea affects ichthyoplankton distribution.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.3
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• pp.245-253
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• 2001

To investigate the effects of hydromechanical and textural characteristics of sediment deposits on the cultivation of Manila clam, Ruditapes philippinarum surface and sub-surface core sediments were collected seasonally in Gomso tidal flat. Grain size distribution were analyzed to investigate the annual variation of sediment texture. In winter unimodal distribution of grain size with the peak at $5\phi$ is dominant However, during the summer sediment texture become a little bit coarser and grain size distribution shows the peaks at $4\~5 \phi$. Optimum sediment texture for the cultivation of manila clam, R. philippinarum was found to be sandy silt in which mean Brain size was between 4 and $5 \phi$ with the sand content less than $50\%$ and clay content of $5\~10\%$. Mechanical and hydrological characteristics of sediment deposits were also studied in the laboratory and the results were applied to the numerical simulation for the behavior of surface sediment subjected to the cyclic loading from sea-water level change. Results of numerical simulation illustrate that the permeability of sediment had to be maintained in the range of $10^{-11}\sim10^{-12}m^2$ to ensure the proper sedimentological environment for the cultivation of manila clam, R. philippinarum. The deposits of virtually impermeable mud layer, with the threshold thickness of 4 cm, would be very hazardous to clam habitat.

• Journal of the Korean Society of Food Science and Nutrition
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• v.18 no.1
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• pp.109-114
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• 1989

Bound lipids(BL) of naked barley(Hordeum vulgare L.) were extracted by different methods and the composition of BL was determined by the procedures of column chromatography, thin layer chromatography and gas chromatography. For the extraction, after free lipids were removed from barley flour by petroleum ether(PE) extraction and then BL were extracted from PE treated flour by the solvent systems of water-saturated butanol(WSB) at $25^{\circ}C$(WSB-LT) and at $95^{\circ}C$ (WSB-HT). BL were extracted by WSB-HT with higher extraction yield as 1.5% as dry basis of flour. The contents of neutral lipids(NL), glycolipids(GL) and phospholipid(PL) in BL were $20.7{\sim}35.5%$, $28.7{\sim}32.4%$, $32.1{\sim}50.6%$, respectively with particularly higher content of PL in WSB-HT as 50.6%. Digalactosyl-diglycerides $(40.2{\sim}44.8%)$, monogalactosyl-diglycerides $(20.3{\sim}31.1%)$, sterly glycerides$(11.2{\sim}15.2%)$ and cereb rosides$(11.6{\sim}12.9%)$ were observed in GL. Of the PL in BL, lysophosphatidyl choline, phosphatidyl choline and phosphatidyl serine, and phosphatidyl ethanolamine were the major components. The predominent fatty acids of NL, GL and PL were linoleic and palmitic acids, however, no significant difference was observed in the composition of fatty acids between two extraction methods.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.44 no.1
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• pp.81-87
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• 2018

The objective of this article is to provide analytical tools for the scattering of stratum corneum (SC) and to check whether the optical clearing agents (OCAs) could be applied in optics affecting the scattering reduction. Dark field images of tape striped corneocyte separates scattered light of the SC from others in vitro. Several optical clearing agents were tested to reduce the scattering. Physical properties of SC such as water contents, keratin configuration and volume after OCAs treatment were investigated by FT-IR and 3D laser microscope. Several reducing sugars, monomeric sugars, sugar alcohol, and hyaluronic acid, which were used as humectants in cosmetic field, also reduced scattering. However, unlike dehydration in optics, water penetrated into the keratin in SC and scattering was decreased at low concentration of OCAs. In that condition, the volume of corneocyte was increased and stiffness seemed to decrease. The analyzing of tape-stripped SC, showed the change of optical and physical properties of corneocyte by optical clearing agents. The hydration of SC layer by optical clearing agents decreased the scattering of corneocyte and thus improved the skin appearance and moisturizing effect, which are important benefits in the cosmetic field and could provide new possibility to develop skin care study targeting at SC.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.4
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• pp.545-553
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• 2003

To achieve good dentin bonding, we must obtain proper wet dentin surface. The purpose of this study was to compare dentin surface according to different wetness degree by AFM image as studying how to obtaining proper wet dentin surface. Intact recently extracted primary teeth were used in the study. The extracted teeth were stored in distilled water at $4^{\circ}C$ until prepared. The teeth were used to prepare 1mm thick dentin disks with exposed surfaces parallel to the occlusal surfaces. The surface of the dentin were polished with polishing disk. The sample were ultrasonically cleaned with distilled water. The sample of each group were treated by different ways. We compared dentin surface of each group by AFM image. From the experiment, the following results were obtained. 1. Acid etching in the dentin surface of primary teeth, resulted in the removal of the smear layer, which opened dentinal tubules, caused the demineralization of peritubular and intertubular dentin, and exposed a collagen-rich transition zone. 2. If the etched dentin was so dehydrated, the intertubular dentin surfaces deceased in height and the diameters of the dentinal tubules decreased slightly. 3. In the group dried with compressed air for 20 seconds at 2 cm, the dentin surfaces were too excessive dried and dehydrated. 4. In the group dried with compressed air for 3 seconds at 2 cm, dry cotton, wet cotton, microbrush and absorbent tissue paper, the dentin surfaces were properly wet.