• Journal of Animal Science and Technology
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• v.50 no.2
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• pp.265-272
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• 2008

The CCAAT/enhancer binding protein β(C/EBPβ), a member of the leucine zipper DNA-binding protein of transcription factor, plays a crucial role in the control of early phases of adipocyte differentiation. In this studies, we report the identification, characterization, and expression of the Korean native cattle C/EBPβ gene. The Korean native cattle and black cattle C/EBPβ cDNA includes a 1047bp open reading frame encoding a protein of 348 amino acids. The C/EBPβ cDNA sequence of the Korean native cattle and black cattle shows high conservation with the corresponding amino acid sequences reported in other species. The distribution of C/EBPβ mRNA in various tissues of Korean native cattle aged 26 months was investigated using Northern Blot analysis. The C/EBPβ expression was detected in adipose tissue, lung, sirloin while expression was not detected in heart, kidney, small intestine, colon, and liver. However, we are analyzed polymorphism of bZIP domain in the C/EBPβ gene. A polymorphism was not identified at this position.

• Korean Journal of Environmental Agriculture
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• v.3 no.1
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• pp.63-70
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• 1984

The terrestrial UV flux rapidly increased in late spring, as measured by the chemical actinometry at two elevations (near sea level and 1,100m above sea level) on Jeju Island. More intense UV fluxes were observed at higher altitudes. Any harmful effects of solar UV-B on the growth of soybean were not detected in UV-B-exclusion experiment. To ascertain the effect of UV radiation on vegetative growth, intact (㏖ wt 124000) and large (${\sim}120000$) phytochromes were irradiated with UV-B radiation. In intact phytochrome, the Pfr form accounts for 60% of the total phytochrome under stationary state conditions, whereas it accounts for 50% in large phytochrome. Calculated quantum yields for the forward and the backward phototransformations of phytochrome by UV were ${\phi}r=0.016$ and ${\phi}fr=0.010$ in intact phytochrome, and ${\phi}r={\phi}fr=0.012$ in large phytochrome, respectively.

• Korean Journal of Optics and Photonics
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• v.17 no.6
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• pp.556-563
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• 2006

We present a comprehensive study of a chirped pulse Ti:sapphire regenerative amplifier system operating at 1 kHz. Main constituents of the system are described in detail. The amplifier stage was first converted to a repetition rate-tunable kHz gain-switched nanosecond Ti:sapphire laser. Operation characteristics at different repetition rates such as build-up times of laser pulses, pump power-dependent output powers and pulse durations, damage thresholds, and tunability ranges were studied. Based on the results achieved, the switching time of the Pocket's cell used and the round trip numbers in the regenerative amplifier were optimized at 1 kHz. The output pulses with a pulse width of 50fs from a home-made Ken lens mode-locked Ti:sapphire oscillator were used as seed pulses. The pulses were expanded to 120ps in a grating stretcher prior to coupling into the 3-mirror amplifier cavity. After amplification and recompression, a stable 1kHz Ti:sapphire regenerative amplifier system, which delivers 85-fs, $320-{\mu}J$ pulses, was fully constructed.

• Korean Journal of Food Science and Technology
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• v.34 no.5
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• pp.787-791
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• 2002

Optimal extraction, separation, and capillary rinsing conditions for capillary electrophoresis (CE) were established to identify the cultivation site (domestic vs. foreign) of Job's-tears (Coix lachrymajobi var. mayuen) using 240 samples (domestic sample n = 121, foreign sample n = 119). Job's-tears was extracted with 30% ethanol and separated on a $50-{\mu}m-I.D.$ untreated fused-silica capillary. Optimal analytic conditions were: temperature, $45^{\circ}C$; voltage, 15 kV; detector rise time, 0.1 sec; and pressure injection, 20 sec. Separation of peak investigated using 0.1 M phosphate buffer (pH 2.5) containing 0.05% hydroxypropylmethylcellulose (P buffer) revealed the optimal separation buffer was P buffer containing 26 mM hexane sulfonic acid with 30% methanol. Under the optimal conditions established for CE, the average correct identification percentage of domestic or foreign Job's-tears was 82%.

• Journal of the Microelectronics and Packaging Society
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• v.27 no.2
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• pp.33-38
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• 2020

In the photoelectrochemical (PEC) water splitting, GaN is one of the most promising photoanode materials due to high stability in electrolytes and adjustable energy band position. However, the application of GaN is limited because of low efficiency. To improve solar to hydrogen conversion efficiency, we introduce a Cobalt Phosphate (Co-pi) catalyst by photo-electrodeposition. The Co-pi deposition GaN were characterized by SEM, EDS, and XPS, respectively, which illustrated that Co-pi was successfully decorated on the surface of GaN. PEC measurement showed that photocurrent density of GaN was 0.5 mA/㎠ and that of Co-pi deposited GaN was 0.75 mA/㎠. Impedance and Mott-Schottky measurements were performed, and as a result of the measurement, polarization resistance (R_p) and increased donor concentration (N_D) values decreased from 50.35 Ω to 34.16 Ω were confirmed. As a result of analyzing the surface components before and after the water decomposition, it was confirmed that the Co-pi catalyst is stable because Co-pi remains even after the water decomposition. Through this, it was confirmed that Co-pi is effective as a catalyst for improving GaN efficiency, and when applied as a catalyst to other photoelectrodes, it is considered that the efficiency of the PEC system can be improved.

• Korean Chemical Engineering Research
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• v.50 no.2
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• pp.292-299
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• 2012

We made 8 wt% silica dispersion system with fumed silica and photo curable acrylic monomer by beads mill process. These dispersions could be applied in organic/inorganic hybrid coating systems. These dispersions could be applied in organic/inorganic hybrid coating systems. The 4 species of photo curable acrylic monomer which was presence of hydroxyl group, different solubility parameter, and different molecular size were used in the silica dispersions. Stability of polar solvent, isopropyl alcohol, in silica dispersions was investigated. We investigated the stability of silica dispersions by using steady-state and dynamic rheology. As the monomer has hydroxyl group increased in mono and binary monomer silica dispersions, they showed non flocculated stable sol (loss modulus (G")> storage modulus (G')). When polar solvent IPA was added into slightly flocculated silica dispersions, they changed to non flocculated stable sol.

• Korean Journal of Food Science and Technology
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• v.37 no.4
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• pp.513-518
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• 2005

Capillary electrophoresis (CE) method was developed to determine (+)-catechin and (-)-epicatechin contents in grape seed ethanol extract. CE separation was achieved using 100 mM phosphate and borate buffer at pH 6.0 as background electrolyte and fused silica capillary with 50 microns x 375 microns O.D. (effective length 20.0cm) maintained at $25^{\circ}C$. The applied voltage was 10kV, and detection was performed by DAD at 210 nm, Two catechins were well separated within 6 min with repeatability of <0.8% RSD for migration time and <2.0% RSD for peak area, and correlation coefficients higher than 0.994 were obtained from 58.0 to 174.0 mg/L with detection limit of 0.035 mg/L. Separated compounds were successfully determined. CE method was easy to handle and showed good reproducibility. CE method was compared with conventional coloring and HPLC methods, and main advantages of CE method were low amount of sample required, simple pre-sample treatment, good recovery rate, and short analysis time.

• Journal of Sericultural and Entomological Science
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• v.35 no.1
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• pp.60-68
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• 1993

It has been known that the silk degumming treated by hot alkali solution is easy to handle but is liable to yield poor-quality silk due to the degree of degumming loss, incomplete-degumming or over-degumming. Therefore, many studies have been carried out on the silk degumming by enzyme in order to improve the quality of silk. However, no attention has been paid to the physicochemical analysis of enzymatic degummed silk. In this paper, two different degumming methods, soap and enzymatic, are compared in aqueous solution state of silk fibroin. The results can be summarized as follows: There was no significant difference between two solutions on the bases of polarizing microscopy, TEM observation and SDS-PAGE. Spherulite of silk fibroin was not observed in polarizing microscopy, however the leaf-shape fibril structure was developed upon solidification. The size of spherulites of silk fibroin in TEM observation were 30~120nm with a wide range of size distribution. The intrinsic viscosity of enzymatic degummed fibroin solution was lower than that of soap degummed solution. This can be explained that the silk fibroin was more degraded by enzymatic degumming method compared with the soap degumming method. SDS-polyacrylamide gel electrophoresis showed that the fibroin molecule was composed of large component of molecule weight above 50 kd and small component of molecule weight about 20 kd. There was no difference in crystallinity between two degumming methods on the bases of results of DSC thermograms and IR spectra.

• Journal of Society of Preventive Korean Medicine
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• v.15 no.1
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• pp.37-47
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• 2011

Objectives : Previous studies have shown that Fructus mume (FM) has anti-platelet effects. The present study was performed to determine the acute oral toxicity and quality control of a crude extract of FM in ICR mice. Methods : We investigated the in vivo single dose acute toxicity of FM 95% ethanol extract. This test was orally administered once by gavage to 20 male and 20 female mice at dose levels of 0 (control group), 1250, 2500 and 5000mg/kg body weight, respectively. Mortalities, clinical findings, autopsy findings and body weight changes were monitored daily for the 14 days following the administration. HPLC analysis was performed for the simultaneous determination of ursolic acid and p-hydroxycinnamic acid in FM. Reverse-phase chromatography using a C18 column and photodiode array detection at 211 nm was used for quantification of the two maker components. The mobile phase for gradient elution consists of water and acetonitrile. Results : We observed survival rates, general toxicity, change of body weight, and autopsy. The mice did not die after single oral administration of maximum dose of FM. Autopsy of animal revealed no abnormal gross finding. Therefore, $LD_{50}$ value of FM for ICR mice was more than 5000mg/kg on oral route. The HPLC analysis showed that ursolic acid and p-hydroxycinnamic acid amounts to 9.75- and 0.12% in the extract with the retention times of 47.99- and 15.38 minutes, respectively. Conclusions : These results suggest that no toxic dose level of FM in mice is considered to be more than 5000mg/kg. Consequently, it was concluded that FM have no effect on acute toxicity and side effect in ICR mice. For the quality control of FM extract, simultaneous determination of ursolic acid and p-hydroxycinnamic acid was established.

• Journal of the Korean Society of Food Science and Nutrition
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• v.12 no.4
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• pp.350-356
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• 1983

Ginseng is one of the most important plant drugs which has been used as a medicine in Asia. Main effective components of ginseng have been recently believed to be saponins which have been isolated and identified from Panax ginseng C. A. Meyer. Decrease in total saponin content of white ginseng by storage years was remarkable in contrast with red ginseng. In storage for three years, decrease in red and white ginsengs were 12% and 27% for total saponin content, and 16.8% and 42.2% for major saponin content, respectively. The PT/PD ratios of red and white ginseng saponins were ranged 0.646 to 0.694% and 0.414 to 0.428%, respectively. According to the result of PT/PD ratios, red ginseng was greater than 50% in compare with white ginseng. The change of PT/PD ratio would greatly influence on the biochemical and pharmacological effects of ginseng.