• Membrane Journal
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• v.15 no.1
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• pp.8-14
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• 2005

The hyaluronic acid (HA) with excellent biocompatibility can be combined with the monomer polylactide with good biodegradability to produce biocompatible materials which can control the period of degradation in a human body. By freeze drying method, HA and the lactic acid, monomer of polylactide, or lactide, the ester dimer of polylactide, were crosslinked with crosslinking agent, l-ethyl-3-(3-dimethyl aminopropyl) carbodiimide. The analysis of infrared spectroscopy showed that the ester linkage was formed and the analysis of nuclear magnetic resonance (NMR) spectroscopy showed that the ester linkage was due to the reaction of lactic acid and HA. The conversion (6∼32%) and degree of crosslinking (4∼19%) increased but the selectivity was almost constant at 62% as the mole ratio of LA to HA increased from 1 to 10 in the crosslinking reaction. The brittleness became more pronounced and the rate of degradation became faster with more addition of lactic acid resulting from the higher ratio of LA to HA, and the swelling ratio was in the range of 500 to 2000%.

• Journal of the Korean Ceramic Society
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• v.41 no.1
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• pp.86-91
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• 2004

$LiCoO_2$ cathode powders with round particle shaped and nano grain sized of 70-300nm were synthesized by a mechanochemical method. The surface of Li-Co precursor prepared by freeze drying method was modified by $K_2SO_4$ coating and ball milling was used for the coating process. The precursor was crystallized to high temperature form of $LiCoO_2$ at $800^{\circ}C$ and the grain growth was inhibited by the $K_2SO_4$ coating effect. The $K_2SO_4$ coating was not decomposed at $800^{\circ}C$ and prevented the contact in the Li-Co precursor particles. The nano-sized $LiCoO_2$ powder had tetragonal phase and it affected the Li diffusion through the surface of particles. It means that the anode materials for hight performance battery should be satisfied not only small particle size but phase contol on the surface of particles. In this study, the powder characteristics and rate capabilities were compared with a commercial powder and the nano-sized $LiCoO_2$ powder fabricated by the mechanochemical method. And the crucial factor which affects on battery performance was also examined.

• Korean journal of food and cookery science
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• v.32 no.1
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• pp.50-57
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• 2016

In this study, kim (dried laver) bugak ("KB"), Aster yomena bugak ("SB"), and namul (vegetables)-kim bugak (combination of Aster yomena and kim) ("NB") were prepared and their quality characteristics were investigated. NB was made by slicing Aster yomena, seasoning it with perilla seeds, attaching it to kim and applying glutinous rice paste, followed by freeze-drying. SB had a higher oil absorption rate than KB, reflecting the high oil absorption rate of namul (here, Aster yomena). DPPH radical scavenging activity was highest for SB; whereas, NB had higher DPPH radical scavenging activity than KB, indicative of the higher antioxidant capacity of namul, as compared to kim. With longer storage period, moisture content tended to be increased, while maximum load, yield stress and hardness tended to be decreased. Overall preference was in the order of NB>KB>SB, without statistical significance. Acid value and peroxide value of NB, stored at $25^{\circ}C$ for 40 days, tended to be increased gradually but did not meet the criteria for rancidity. Therefore, NB could be stored at $<25^{\circ}C$ for > 40 days. Furthermore, it would be possible to make functional bugak using a variety of namul, as well as Aster yomena.

• Journal of Pharmaceutical Investigation
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• v.24 no.2
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• pp.95-104
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• 1994

Inclusion complexes of ketoconazole(KT) with ${\alpha}^_$, ${\beta}^_$cyclodextrin(CD) and $dimethy1-{\beta}-cyclodextrin$ (CD) and $dimethy1-{\beta}-cyclodextrin(DM{\beta}CD)$ as nasal absorption enhancer were prepared in 1: 2 molar ratios by freeze-drying and solvent evaporation methods. In order to compare with the intrinsic absorptivity of KT in the jejunum(J) and the nasal cavity(N), the in situ simultaneous perfusion method was employed. The in situ recirculation study revealed that KT-CD inclusion complexes with the greater stability constant and the faster dissolution rate proportionally increased the absorption of KT in the J and N of rats. The rank order of apparent KT permeability$(P_{app}\;:\;cm/sec\;{\time}\;1O^{-5}{\pm}S.E.)$, corrected by surface area of absorption, was $5.10{\pm}0.3(N,\; KT-DM{\beta}CD)$ )> $4.13{\pm}0.4(N,\;KT-{\beta}-CD)$ )> $3.52{\pm}0.2(N,\;KT-{\alpha}-CD)$ )> $2.76{\pm}0.3(J,\; KT-DM{\beta}CD)$ )> $2.61{\pm}0.5(J,\;KT-{\beta}-CD)$ )> $2.42{\pm}0.4(J,\;KT-{\alpha}-CD)$ at pH 4.0. The in crease in permeability of $KT-DM{\beta}CD$ inclusion complex was 2.6 folds in the J and 4.5 folds in the N when the perfusing solution was changed from the buffer(pH 4.0) to saline. The absorption rate of $KT-DM{\beta}CD$ inclusion complex after nasal administration was more rapid than those of ketoconazole alone and $KT-DM{\beta}CD$ inclusion complex after oral administration to rats. In comparision with an oral administration of ketoconazole suspension in corn oil, the relative bioavailability was calculated 137.3% for the oral and 195.0% for nasal $KT-DM{\beta}CD$ inclusion complex in rats. The present results suggest that $KT-DM{\beta}CD$ inclusion complex may serve as a potential nasal absorption enhancer for the nasal delivery of ketoconazole.

• The Korean Journal of Food And Nutrition
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• v.18 no.3
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• pp.207-218
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• 2005

In room temperature, Kimchi becomes acidified and a little decayed, scenting a bad smell, and It couldn't be well kept. But if it should be made into a pill, it could be preserved for a long time for marketing, with nutrition highly concentrated as well as with no scent. Therefore, making Kimchi into a pill needs drying. When dried Kimchi, lactic acid and fragrant ingredient will vanish along with volatilization. The cyclodextrin(CD) as a stabilizer shows that the protecting rate of volatility of lactic acid in Kimchi is higher before than that of after fermentation, and it is higher at the addition $2\%\;than\;of\;1\%$ in case of Kimchi with CD. But it doesn't give much effect on total sugar, reducing sugar, protein and amino acid. Evaporation rate of lactic acid is the least in freeze dry, and natural dry, heat dry come next, respectively. In heat dry, if dried at more than $60^{\circ}C$ for a long time, Kimchi exudes boiling and scorched scent, causing bitter taste. The result of HPLC with superose 12 column at 280nm and 210nm shows that place and amount of main peak is almost the same, but the distribution of other peaks are different, with the revelation of various peaks like peptide and amino acid. The Kimchi pill made by the addition of $1\%$ CD shows that concentration is eight times higher than general Kimchi, total sugar is $14.4\%$, reducing sugar is $8.8\%$, protein is $4.8\%$, amino acid is $2.4\%$, and other contents are $74.4\%$, acidity is 32.8, and pH is 3.5 each. The result of letting 20 people with obesity, 20 patients with constipation have 30 pills(total weight 30g) three times a day for 60 days reveals they lost $2.29\%$ in weight on the average, and 7 among 20 were all relieved in constipation, and 8 responded that they experienced its efficacy.

• The Korea Journal of Herbology
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• v.21 no.2
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• pp.95-101
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• 2006

Objectives : This study aimed to establish cosmeceutical activities of Perilla frutescens var. acuta. Methods : Folium Perillae, which had been extracted, concentrated, and freeze drying with water and ethanol, have been used for the experiment. The effects on electronic donating ability, SOD-like activity, xanthine oxidase inhibition, whitening effect have been investigated in the cosmeceutical activity measurement of function experiment. Results : Both water and ethanol extracts of Perilla frutescens var. acuta showed relatively high electron donating ability of more than 70% at over 500ppm. Also, SOD like activity increased in a dose dependent matter of more than 80% at 5,000ppm, while tyrosinase showed insufficient inhibitory rate. Xanthine oxidase showed a meaningful inhibitory effect of 72.4% in water extract and 55.3% at 1,000ppm in ethanol extract. The addition of $Fe^{2+}ion\;and\;Cu^{2+}ion$ showed relatively high oxidizing inhibitory effect of 57% and 41%, respectively, at 500ppm in water extract and, when $Fe^{2+}$ ion was added in ethanol extract, the effect of 64% at 1,000ppm was achieved. Also, higher oxidizing inhibitory effect was shown against $Fe^{2+}$ rather than $Cu^{2+}$ in both water and ethanol extracts. For human cancer cells, relatively high growth inhibition ability was shown against melanoma G361 in both water and ethanol extracts. Conclusion : From the above results, it was confirmed that Perilla frutescens var. acuta could be used in functional cosmetics.

• Journal of the Korean Applied Science and Technology
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• v.31 no.4
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• pp.635-641
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• 2014

Archaeological waterlogged woods require a process of dimensional stabilization for their conservation. PEG is the most widely used in the conservation of archaeological waterlogged wood. One of the easiest and commonly used methods is the impregnation of 40% polyethylene glycol followed by vacuum freeze drying. However, the waste fluid produced from the PEG treatment is black in color and has a severe odor due to the organic matter extracted from the wood. Thus It cannot be recycled and it was just thrown out. Color of waste fluid can be decolored with oxidation reaction by hydrogen peroxide. Properties of PEG before and after preservation treatment, and after oxidation with $H_2O_2$ were not changed. Dimensional stability of archaeological waterlogged Salix koreensis Andersson was studied with pure or recycled PEG. The ratio of impregnation solutions were 10:0, 7:3, 5:5, 3:7, 0:10 (pure PEG : recycled PEG). Impregnation process was carried out by putting the wood specimens 10% PEG solution for 5days, 20% for 5 days, 30% for 5 days finally 40% for 5 days. All of the specimens showed the weight change rate of 25%. SEM results provided that the dimensional change of were less than 4% PEG impregnated specimens. Comparing with pure PEG impregnation system, conservation precess mixed PEG also showed no significant changes. Conclusively, the recycled PEG can be used for archeological waterlogged wood conservation precess.

• Journal of Periodontal and Implant Science
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• v.32 no.3
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• pp.489-500
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• 2002

The purpose of this study was to evaluate newly fabricated tricalcium phosphate(TCP)/chitosan microgranuls as bone substitutes. TCP/chitosan microgranules were fabricated by dropping TCP-chitosan suspension into the NaOH/ethanol solution. The size of microgranules could be controllable via airflow rate. PDGF-BB was loaded into the fabricated granules via freeze-drying methods(300 ng/20 mg). To evaluate cell proliferation, cultured osteoblasts cell lines(MC3T3-El) was dropped on the BioOss(R), chitosan microgranules, TCP/chitosan microgranules and cultured for 1, 7 , 14, and 28 days. Scanning electron microscopic observation was done after 7 days of culture and light microscopic examination was done after 28 days of culture. PDGF-BB release from the microgranules was tested. Rabbit calvarial defects(8 mm in diameter) were formed and chitosan, TCP/chitosan, PDGF-TCP/chitosan microgranules, and BioGran(R) were grafted to test the ability of new bone formation. At SEM view, the size of prepared microgranules was 250-1000 um and TCP powders were observed at the surface of TCP/chitosan microgranules. TCP powders gave roughness to the granules and this might help the attachment of osteoblasts. The pores formed between microgranules might be able to allow new bone ingrowth and vascularization. There were no significant differences in cell number among BioOss(R) and two microgranules at 28 day. Light and scanning electron microscopic examination showed that seeded osteoblastic cells were well attached to TCP/chitosan microgranules and proliferated in a multi-layer. PDGF-BB released from TCP/chitosan microgranules was at therapeutic concentration for at least 1 week. In rabbit calvarial defect models, PDGF-TCP/chitosan microgranules grafted sites showed thicker bone trabeculae pattern and faster bone maturation than others. These results suggested that the TCP/chitosan microgranules showed the potential as bone substitutes.

• Korean Journal of Food Science and Technology
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• v.35 no.3
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• pp.393-398
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• 2003

Effects of convection oven dehydration conditions on the physicochemical and sensory properties of ginkgo nut powder were examined using three types of pre-treatment on ginkgo nuts: coarse grinding of ginkgo nut (GR); coarse grinding followed by 1 min blanching (GB); 3 min blanching followed by coarse grinding (BG). Pretreated ginkgo nuts were dried in convection oven at 70 and $80^{\circ}C$ to the moisture content of approximately 5%. Rehydration rate, swelling power, solubility, lightness, and greenness of GB ginkgo nut powder dried at $70^{\circ}C$ were the most similar to those of freeze dried one. GR and GB samples dried at $70^{\circ}C$ had higher sensory values of green color and ginkgo nut flavor. Ginkgo nut powder with desirable quality attributes could be produced by drying GB in convection oven at $70^{\circ}C$ for 10 hr.

• Clean Technology
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• v.18 no.2
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• pp.191-199
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• 2012

In order to reduce or remove off-flavor and volatile organic compounds (VOCs) from Laminaria japonica effectively, continuous treatment process by supercritical carbon dioxide (SC-$CO_2$) was applied. After freeze-drying, Laminaria japonica powdered with $710{\mu}m$ was used. Experiments were carried out at temperature range from 35 to $55^{\circ}C$, and pressure range from 10 to 25 MPa for evaluation of SC-$CO_2$ treatment effect. Flow rate of carbon dioxide used in this reseach was constantly fixed at 26.81 g/min. Before and after treatment of SC-$CO_2$, off-flavor and VOCs from Laminaria japonica were analyzed by gas chromatography-mass spectrometry detector (GC-MSD). Total 47 VOCs emitted from Laminaria japonica were identified before treatment of SC-$CO_2$, major components of seaweed smell (ordor) in Laminaria japonica were identified as alcohols, aldehydes, ester and acids, ketone, halogenated compounds and hydrocarbon. Off-flavor and VOCs in all experimental conditions was reduced or removed after SC-$CO_2$ treatment. Among the experimental conditions, the highest removal yield was at 25 MPa and $55^{\circ}C$.