• Journal of the Korean Electrochemical Society
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• v.3 no.1
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• pp.11-14
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• 2000

Transparent conducting ITO thin films have been studied and developed for the solar cell substrate or LCD substrate. ITO thin film has been mostly fabricated by high cost sputtering method. In this research, sol-gel method is applied to fabricate ITO thin film at lower cost. The research is focused on the establishment of process condition and development of precursor. Organic sol was made of indium tri-isopropoxide dissolved in ethylene glycol monoethyl ether. The hydrolysis was controled by addition of acetyl acetone. Tin(IV) chloride was added as dopant. Inorganic sol was made of indium acetate dissolve din normal propanol. Spin coating technique was applied to coat ITO on borosilicate glass. The resistivity of ITO thin film was approximately $0.01\Omega{\cdot}cm$ and the transmittance is higher than $90\%$ in a visible range.

• Journal of Microbiology and Biotechnology
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• v.28 no.11
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• pp.1814-1822
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• 2018

Most people use cosmetics to protect their skin. Preservatives are often used to prevent their contamination upon use. There has been a great demand for natural preservatives due to recent reports on the side effects of parabens. Therefore, we evaluated the antimicrobial activities of Lonicera japonica and Magnolia obovata extracts and determined their potential as natural preservatives. We found that the 50% ethanol extract from L. japonica had antibacterial activity only against S. aureus and P. aeruginosa, while the ethyl acetate fraction showed antimicrobial activity against all six microbial strains tested. On the other hand, the 70% ethanol extract and the ethyl acetate fraction from M. obovata showed antimicrobial activity against all six strains. A synergistic effect against S. aureus, B. subtilis, and C. albicans was confirmed when two ethyl acetate fractions having antimicrobial activity against all six strains were used in combination. Synergistic activity against B. subtilis was also confirmed through kill-time analysis. High-performance liquid chromatography was performed to identify the components of each extract. Based on the minimum inhibitory concentration and the results of a disc diffusion assay, we confirmed that caffeic acid and luteolin influenced the antimicrobial activity of L. japonica and that the antimicrobial activity of M. obovata was influenced by the interaction of magnolol and honokiol with other components. Therefore, this study suggests that the combination of L. japonica and M. obovata extracts may be used as a plant-derived natural preservative.

• Journal of Food Hygiene and Safety
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• v.15 no.2
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• pp.167-172
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• 2000

Lithospermum erythrorhyzon has been used as a red fooddye and traditional Chinese medicine to treat wounds, skin diseases and burns. Platelet activation plays an important role in thrombosis and haemostasis. Here, we studied the inhibition of platelet activation and its active compound from the root of Lithospermum erythrorhyzon. Its ethyl acetate extract inhibited the aggregation of washed rabbit platelets induced by collagen or thrombin. Five naphthoquinone pigments , shikonin , acetylshikonin , is obutylshikonin, $\alpha$-methyl-n-butylshikonin and $\beta$,$\beta$-dimethylacrylshikonin were isolated by means of high pressure liquid chromatography. The structures were determined by comparison of their proton nuclear magnetic resonance spectra. The potency of their inhibition was in the following order : $\beta$,$\beta$-dimethylacrylshikonin$\geq$$\alpha$-methyl-n-butylshikonin>isobutylshikonin>acetylshikonin>shikonin. It is suggested that the size of the aliphatic hydroxy group of shikonin is important for the enhancement of potency.

• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.1
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• pp.48-53
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• 2006

The asymmetric biosynthesis of ethyl (S)-4-chloro-3-hydrobutanoate from ethyl 4-chloro-3-oxobutanoate was investigated by using whole cells of Candida magnoliae JX120-3 without the addition of glucose dehydrogenase or $NADP^+/NADPH$. In a one-phase system, the bioconversion yield was seriously affected on the addition of 12.1 g/L ethyl 4-chloro-3-oxobutanoate. In order to reduce this substrate inhibition, a water/ n-butyl acetate two-phase system was developed, and the bioreduction conditions optimized with regard to the yield and product enantiometric excess value. The optimal conditions were as following: water to n-butyl acetate volume ratio of 1:1, 4.0 g DCW/L active cells, 50 g/L glucose and $35^{\circ}C$. By adopting a dropwise substrate feeding strategy, high concentration of ethyl 4-chloro-3-oxobutanoate (60 g/L) could be asymmetrically reduced to ethyl (S)-4-chloro-3-hydrobutanoate with high yield (93.8%) and high enantiometric excess value (92.7%).

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.12
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• pp.1743-1748
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• 2003

The effect of pH on the fermentation characteristics and the formation of cis-9, trans-11 conjugated linoleic acid (CLA) and trans-11 octadecenoic acid by mixed ruminal bacteria was examined in vitro when incubated with linseed or rapeseed. Concentrate (1%, w/v) with ground linseed (0.6%, w/v) or rapeseed (0.5%, w/v) was added to 600 ml mixed solution of strained rumen fluid with artificial saliva (1:1, v/v), and was incubated anaerobically for 12 h at $39^{\circ}C$. The pH of culture solution was maintained at level close to 4.5, 5.3, 6.1 and 6.9 with 30% $H_2SO_4$ or 30% NaOH solution. pH increment resulted in increases of ammonia and total volatile fatty acid (VFA) concentration in culture solutions containing both oilseeds. Fermentation did not proceeded at pH 4.5. Molar proportion of acetate decreased but that of propionate increased as pH increased when incubated with oilseeds. While the hydrogenating process was very slow at the pH range of 4.5 to 5.3, rapid hydrogenation was found from the culture solutions of pH 6.1 and 6.9 when incubated with linseed or rapeseed. As pH in culture solution of linseed or rapeseed increases proportions of oleic acid (cis-9 $C_{18:1}$) and trans-11 octadecenoic acid increased but those of linoleic acid and linolenic acid decreased. The CLA proportion increased with pH in culture solution containing rapeseed but CLA was mostly not detected from the incubation of linseed.

• Bulletin of the Korean Chemical Society
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• v.23 no.1
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• pp.81-85
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• 2002

A new di-N-cyanoethylated 14-membered tetraaza macrocycle 1,8-bis(2-cyanoethyl)-3,5,7,7,10,12,14,14-octamethyl-1,4,8,11-tetraazacyclotetradecane $(L^2)$ and its nickel(II) complex $[NiL^2(OAc)]^+$ have been prepared. The square-planar complex $[NiL^2](C IO_4)_2$ can be prepared by addition of $HClO_4$ to a hot aqueous solution of $[NiL^2(OAc)]^+$ The Ni-N (tertiary amino group) bond distances $(2.008{\AA})$ of $[NiL^2](C IO_4)_2$ are relatively long, and the complex exhibits a d-d transition band at unusually long wavelength (ca. 515 nm). The complex $[NiL^2](C IO_4)_2$ rapidly reacts with acetate ion or ethylenediamine (en) to produce $[NiL^2(OAc)]^+$ or [Ni(en)_3]^{2+}$, respectively, and is readily decomposed in NaOH (0.01 M) solution. The chemical properties of $[NiL^2]^{2+}$ as well as its synthetic procedure are quite different from those for other related 14-membered tetraaza macrocyclic complexes. Effects of the N-cyanoethyl and C-methyl groups on the properties of $L^2$.

• Journal of the Korean Ceramic Society
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• v.30 no.9
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• pp.695-700
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• 1993

In this study, we prepared Pb-Ti stock solution by sol-gel processing and deposited PbTiO3 thin film on a Pt coated SiO2/Si wafer by spin coating using the stock solution. We used lead acetate trihydrate and titanium isopropoxide. The stock solution was partially hydrolized and finally a 0.25M coating solution was prepared. We achieved spin coating at 4000rpm for 30 seconds and heated the thin film at 375$^{\circ}C$ for 5 minutes and at $600^{\circ}C$ for 5 minutes successively, first and second heating state. And the thin film was finally sintered at 90$0^{\circ}C$ for 1 hour in the air. The upper electrode of the thin film was made by gold sputtering and was cricle shape with radius 0.4mm. Measured dielectric constant, dissipation factor and phase transition temperature(Cuire Temp.) were about 275, 0.02 and 521$^{\circ}C$ respectively. To observe ferroelectric characteristics we calculated Pr(remnant polarization) and Ec(coercive field) byhysteresis curve. Ec was 72kV/cm and Pr was 11.46$\mu$C/$\textrm{cm}^2$.

• Natural Product Sciences
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• v.20 no.3
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• pp.182-190
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• 2014

An ultra-performance liquid chromatography (UPLC) coupled with electrospray ionization (ESI) tandem mass spectrometry (MS) method was established for quantitative analysis of twelve components, allantoin (1), morroniside (2), 5-hydroxymethyl-2-furfural (5-HMF) (3), loganin (4), coumarin (5), cinnamic acid (6), mesaconitine (7), cinnamaldehyde (8), hypaconitine (9), aconitine (10), alisol B (11), and alisol B acetate (12) in a Palmijihwang-hwan decoction. The twelve constituents were separated on a UPLC BEH C18 column ($2.1{\times}100mm$, $1.7{\mu}m$) at a column temperature of $40^{\circ}C$ by gradient elution with 0.1% (v/v) formic acid in water and acetonitrile as the mobile phase. The flow rate was 0.3 mL/min and the injection volume was $2.0{\mu}L$. Calibration curves of all compounds were acquired with values of the correlation coefficient ${\geq}0.99$ within the test ranges. The limits of detection and quantification for all analytes were 0.01 - 4.53 ng/mL and 0.03 - 13.60 ng/mL, respectively. The concentrations of the compounds 1 - 9 and 12 were 72.83, 4389.00, 4859.00, 3155.17, 223.67, 33.50, 1.97, 518.00, 2.25, and $25.00{\mu}g/g$, respectively. However, compounds 10 and 11 were not detected.

• Journal of the Korean Wood Science and Technology
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• v.44 no.4
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• pp.494-504
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• 2016

Eucalyptus oils are widely used as spices, perfume industrial materials, food flavorings, and medicines. Several types of Eucalyptus oils also have insecticidal activity and as carminative. This study investigated the chemical composition, insecticidal (larvicidal and repellent) activity of E. urophylla oil against filarial mosquito Culex quinquefasciatus. E. urophylla oil was obtained from fresh leaves by water-steam distillation with oil yield 1.08%. E. urophylla oil in this study had no color (clear), has odor (typical eucalyptus), with specific gravity 0.941; refractive index 1.465; miscibility in 70% ethanol 1 : 3; and optical rotation (-) $5.83^{\circ}$. The major compounds of the oil were ${\alpha}$-pinene (11.73%), 1,8-cineole (49.86%), ${\beta}$-ocimene (6.25%), ${\gamma}$-terpinene (9.11%), and ${\alpha}$-terpinyl acetate (7.63%). The result showed the excellent insecticide activity against C. quinquefasciatus. The oil provided larvicidal activity with $LC_{50}$: 80.21 ppm and $LC_{90}$: 210.18 ppm, and repellent activity with $IC_{50}$: 0.82% and $IC_{90}$: 4.88%. The present study showed the effectiveness of E. urophylla as natural insecticide against C. quinquefasciatus, the mosquito vector of filariasis.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.1
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• pp.42-46
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• 2003

This research was carried out for searching the treatment conditions of organic acid and heating to prepare oligomers from the carrageenan. The applied treatments were autoclaving, micraowaving, and ultrasonicating with acetate, citrate, lactate, malate, and succinate. Among several physical depolymerization methods, auo-claving treatment was the most effective for hydrolyzing the carrageenan to low molecular compounds such as oligosaccharides. Citrate or malate was the most effective catalyst in hydrolyzing carrageenan to some oligo-saccharides among 5~7 different organic acids. An acceptable autoclaving condition for hydrolyzing carrageenan to oligosaccharides was to treat for 120 min at 110~12$0^{\circ}C$. The maximum depolymerization ratio produced by autoclaving was about 23.0%. The depolymerized carrageenan prepared by autoclaving at 12$0^{\circ}C$ had oligo-saccharides of 5~7 species.