• Journal of Microbiology and Biotechnology
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• v.6 no.3
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• pp.209-212
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• 1996

A two-step cooling technique has been developed for cryopreservation of suspension cultured Scutellaria baicalensis cells. Efficient regrowth of cryopreserved cells was obtained in cryoprotected cells with a mixture of 1.5 M glycerol and 0.4 M sucrose in Schenk and Hildebrandt medium without pretreatment in high osmotic medium. Optimum freezing conditions were found to be a cooling rate of $0.5^{\circ}C$ min from $4^{\circ}C$ to $-40^{\circ}C$, and then retaining samples at $-40^{\circ}C$ for 30 min prior to plunging into liquid nitrogen. A regrowth rate of approximately 95$%$ was obtained after three month storage in liquid nitrogen. Callus cultures established from the cryopreserved cells were found to produce the same patterns of flavonoid accumulation and retain their baicalin producing activity.

• Journal of the Korean institute of surface engineering
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• v.28 no.3
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• pp.133-141
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• 1995

The deposition characteristics of diamond films were investigated for three different substrates : Si, Inconel 600 and steel. Diamond films were prepared by microwave plasma CVD method using $CH_4$, $H_2$ and $O_2$ as reaction gases. The deposited films were analyzed with SEM, Raman spectroscopy and ellipsometer. For Si substrate, diamond films were successfully obtained for most of the deposition conditions used in this study. As the $CH_4$ flow rate decreased and the $O_2$ flow rate increased, the quality of the film was improved due to the reduced non-diamond phase in the film. For Inconel 600 substrate, the surface pretreatment with diamond powders was required to deposit a continuous diamond film. The films deposited at temperatures of $600^{\circ}C$ and $700^{\circ}C$ had mainly diamond phase, but they were peeled off locally due to the difference in the thermal expansion coefficient between the substrate and the deposited films. The films deposited at $500^{\circ}C$ and $850^{\circ}C$ had only the graphitic carbon phase. For steel substrate, all of the films deposited had only the graphitie carbon phase. We speculated that the formation of diamond nuclei on the steel substrate was inhibited due to the diffusion of carbon atoms into the steel substrate which has a large amount of carbon solubility.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.88-89
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• 2013

A variety of influenza A viruses from animal hosts are continuously prevalent throughout the world which cause human epidemics resulting millions of human infections and enormous industrial and economic damages. Thus, early diagnosis of such pathogen is of paramount importance for biomedical examination and public healthcare screening. To approach this issue, here we propose a fully integrated Rotary genetic analysis system, called Rotary Genetic Analyzer, for on-site detection of influenza A viruses with high speed. The Rotary Genetic Analyzer is made up of four parts including a disposable microchip, a servo motor for precise and high rate spinning of the chip, thermal blocks for temperature control, and a miniaturized optical fluorescence detector as shown Fig. 1. A thermal block made from duralumin is integrated with a film heater at the bottom and a resistance temperature detector (RTD) in the middle. For the efficient performance of RT-PCR, three thermal blocks are placed on the Rotary stage and the temperature of each block is corresponded to the thermal cycling, namely $95^{\circ}C$ (denature), $58^{\circ}C$ (annealing), and $72^{\circ}C$ (extension). Rotary RT-PCR was performed to amplify the target gene which was monitored by an optical fluorescent detector above the extension block. A disposable microdevice (10 cm diameter) consists of a solid-phase extraction based sample pretreatment unit, bead chamber, and 4 ${\mu}L$ of the PCR chamber as shown Fig. 2. The microchip is fabricated using a patterned polycarbonate (PC) sheet with 1 mm thickness and a PC film with 130 ${\mu}m$ thickness, which layers are thermally bonded at $138^{\circ}C$ using acetone vapour. Silicatreated microglass beads with 150~212 ${\mu}L$ diameter are introduced into the sample pretreatment chambers and held in place by weir structure for construction of solid-phase extraction system. Fig. 3 shows strobed images of sequential loading of three samples. Three samples were loaded into the reservoir simultaneously (Fig. 3A), then the influenza A H3N2 viral RNA sample was loaded at 5000 RPM for 10 sec (Fig. 3B). Washing buffer was followed at 5000 RPM for 5 min (Fig. 3C), and angular frequency was decreased to 100 RPM for siphon priming of PCR cocktail to the channel as shown in Figure 3D. Finally the PCR cocktail was loaded to the bead chamber at 2000 RPM for 10 sec, and then RPM was increased up to 5000 RPM for 1 min to obtain the as much as PCR cocktail containing the RNA template (Fig. 3E). In this system, the wastes from RNA samples and washing buffer were transported to the waste chamber, which is fully filled to the chamber with precise optimization. Then, the PCR cocktail was able to transport to the PCR chamber. Fig. 3F shows the final image of the sample pretreatment. PCR cocktail containing RNA template is successfully isolated from waste. To detect the influenza A H3N2 virus, the purified RNA with PCR cocktail in the PCR chamber was amplified by using performed the RNA capture on the proposed microdevice. The fluorescence images were described in Figure 4A at the 0, 40 cycles. The fluorescence signal (40 cycle) was drastically increased confirming the influenza A H3N2 virus. The real-time profiles were successfully obtained using the optical fluorescence detector as shown in Figure 4B. The Rotary PCR and off-chip PCR were compared with same amount of influenza A H3N2 virus. The Ct value of Rotary PCR was smaller than the off-chip PCR without contamination. The whole process of the sample pretreatment and RT-PCR could be accomplished in 30 min on the fully integrated Rotary Genetic Analyzer system. We have demonstrated a fully integrated and portable Rotary Genetic Analyzer for detection of the gene expression of influenza A virus, which has 'Sample-in-answer-out' capability including sample pretreatment, rotary amplification, and optical detection. Target gene amplification was real-time monitored using the integrated Rotary Genetic Analyzer system.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.9
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• pp.1351-1357
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• 2016

Green tea (Camellia sinensis) seed extract (GTSE) was prepared under various pretreatment conditions and used to investigate its extraction yield and anti-yeast activity. Anti-yeast activity of GTSE from seeds with or without the coats was the same, whereas the extraction yield was slightly higher in extract from seeds without the coat. Anti-yeast activity of GTSE from seeds with different water contents or particle sizes was the same, whereas the extraction yield was highest in extract from seeds with 7.3% moisture or a smaller particle size. Anti-yeast activity of defatted green tea seed extract (DGTSE) was the same as that of GTSE. Extraction yield was higher in DGTSE from defatted seeds by the oil press machine compared to hexane extraction. Defatted green tea seed (DGTS), a by-product from the oil extraction process, is a good natural source of anti-yeast preservative. The extraction yield and anti-yeast activity of DGTSE were investigated using various extraction solvents, temperatures, and times. The results show that water was an economic extraction solvent, and anti-yeast activity of DGTSE was unstable at $90^{\circ}C$. These results suggest that water, extraction temperature of $50^{\circ}C$, and extraction time of 4 h were the most efficient for extraction of anti-yeast compounds from DGTS.

• Korean Journal of Materials Research
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• v.11 no.4
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• pp.324-328
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• 2001

CrN films were deposited onto STD61 steel substrates using an arc-ion plating apparatus, with and without ion-nitriding pretreatment, and their oxidation was studied between 700 and $900^{\circ}C$ for 40hr in air. The oxidation behavior was examined by thermogravimetric analyses, X-ray diffraction. EDS and SEM. The deposited CrN films consisted of CrN and $Cr_2$N phases. The CrN films increased the oxidation resistance of the substrate by forming a protective $Cr_2$$O_3$ layer. The ion-nitriding pretreatment has not affected the oxidation resistance of the CrN film.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.5
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• pp.849-859
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• 2000

This study was conducted to identify the characteristics of methane fermentation and lysis effects of pre-treated microalgae. Chemical compositions of microalgae showed that the VS(volatile solid) was 86.1% of TS(total solid), and the protein was 63.5% of VS. These values were higher than those of activated sludge. The cell lysis test of raw microalgae biomass was conducted by many physicochemical methods. presenting that the degree of cell lysis was affected by following order: ultrasonic(100min.), alkali(pH 13), ultrasonic(10min), thermal($120^{\circ}C$), thermal($50^{\circ}C$), and acidic(pH 3) treatment. Methane fermentation with many pre-treated samples was performed, showing that the concentration of acetic acid was the highest. followed by propionic acid, butylic acid and valerie acid among all VFA(volatile fattic acid). In methane production. ultrasonic samples were only more effective than untreated one in total gas and methane productivity. but other samples were less effective. Especially. the alkalic sample had an inhibitation effect on methanogens.

• Journal of Plant Biotechnology
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• v.45 no.4
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• pp.347-356
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• 2018

Chionanthus retusus is a small deciduous tree that is widely used in landscaping due to its beautiful white spring flowers and ornamental value. Conventional propagation through seeds requires one to two years of breaking dormancy. The objective of this study was to determine the conditions of in vitro germination in C. retusus. In vitro embryo culture was carried out to investigate the effects of six factors: basal media (McCown Woody Plant Medium (WPM) and Murashige and Skoog (MS)); plant growth regulators (different combinations and concentrations of naphthaleneacetic acid (NAA), 6-Benzylaminopurine (BA), and gibberellic acid ($GA_3$)); embryo age (collected weekly beginning 36 days after fruit setting); low temperature pretreatment (storing $4^{\circ}C$ for 1, 2, 3, and 4 weeks); coconut additives (100, 200, and $300ml{\cdot}L^{-1}$); and genotype (grouping plants depending on their flowering nature). The basal medium used in this study was WPM with $2mg{\cdot}L^{-1-1}\;GA_3$, $20g{\cdot}L^{-1}$ sucrose, and $6g{\cdot}L^{-1}$ Agar. WPM medium mixed with $GA_3$, resulted in higher germination rate as compared to when using a combination of auxin and cytokinin. $GA_3$ at $2mg{\cdot}L^{-1}$ was the most effective of all combinations and concentrations of PGRs. WPM medium with $2mg{\cdot}L^{-1}GA_3$ resulted in better and faster germination (75.93%). Embryos collected at 57 days after fruit setting had the highest percent of germinated seeds (87.04%) while low-temperature pretreatment of fruits at $4^{\circ}C$ for two weeks produced the highest germination (95.37%). These results of this study could be an open ground for development of an efficient protocol for commercial production of the ornamental tree.

• Korean Journal of Food Science and Technology
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• v.36 no.5
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• pp.761-764
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• 2004

Effects of pretreatment conditions on ${\gamma}-aminobutyric$ acid (GABA) contents of brown rice and germinated brown rice were investigated. As steeping time increased, GABA contents of brown rices increased gradually. The highest GABA content, 3.33mg/100g, was found in brown rice steeped at $40^{\circ}C$ for 8 hr. GABA content of brown rice decreased significantly at pH 8 (p<0.05), but changed slightly at pH of steeping solution ranging 4-7. Steeping of brown rices in glutamate solution increased GABA contents. Brown rice steeped in glutamate solution at 200-300 ppm showed GABA content between $4.09{\pm}0.48-4.11{\pm}0,47mg/100g$, which was much higher than that of untreated brown rice. Anaerobic treatment of brown rices using $N_2$ gas increased GABA contents, ranging from $4,70{\pm}0.49\;to\;4.92{\pm}0.83mg/100g$. Germinated brown rice steeped in glutamate solution under anaerobic condition had GABA content of $5.92{\pm}0.72mg/100g$, two-fold higher than that of untreated brown rice, $3.05{\pm}0.67mg/100g$. Optimum pretreatment condition established in this study could significantly increase GABA content in germinated brown rice.

• Korean Journal of Food Science and Technology
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• v.47 no.1
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• pp.56-62
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• 2015

Various pretreatment methods were evaluated to prevent tissue softening of heated onion. Changes in onion tissue firmness during heating were explained by 3-mechanism model consisting of texture hardening at low temperature ($60-80^{\circ}C$) and substrate softening at high temperature. Preheating of onion in a $Ca^{2+}$-containing solution significantly improved its texture after high-temperature heating. The improvement of firmness by preheating at low temperature was related to the formation of strong cross-linking between carboxyl groups and $Ca^{2+}$ by the action of pectin methylesterase in onion. The highest firmness was obtained by pre-heating at $70^{\circ}C$ for 120 min in 0.5% calcium solution. This result was supported by chemical analysis showing that the amount of bound calcium was the highest at $70^{\circ}C$. Further investigation should be carried out to establish the optimal conditions to prevent the softening of various vegetables.

• KSBB Journal
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• v.27 no.2
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• pp.86-90
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• 2012

Ethanol fermentations were carried out using simultaneous saccharification and fermentation (SSF) and separated hydrolysis and fermentation (SHF) processes with monosaccharides from seaweed, Saccharina japonica (sea tangle, Dasima) as the biomass. The pretreatment was carried out by thermal acid hydrolysis with $H_2SO_4$ or HCl. Optimal pretreatment condition was determined at 10% (w/v) seaweed slurry with 37.5 mM $H_2SO_4$ at $121^{\circ}C$ for 60 min. To increase the yield of saccharfication, isolated marine bacteria Bacillus sp. JS-1 was used and 48 g/L of reducing sugar were produced. Ethanol fermentation was performed using SSF and SHF process with Pachysolen tannophilus KCTC 7937. The ethanol concentration was 6.5 g/L by SSF and 6.0 g/L by SHF.