• Microbiology and Biotechnology Letters
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• v.14 no.3
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• pp.213-218
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• 1986

Hybrid plasmid pEA24, shuttle vector YRp7 carrying amylase gene of Bacillus amyloliquefaciens, was transformed to yeast Saccharomyces cerevisiae, and the expression of B. amyloliquefaciens amylase gene in yeast was investigated. The frequency of transformation to S. cerevisiae DBY747 with YRp7 was increased by treatment of 40% polyethylene glycol (MW 4, 000), PH 7.0, at 3$0^{\circ}C$, and by regeneration used 2% top agar. The amount of cellular amylase activity produced by S. cerevisiae containing pEA24 was 2% of that secreted from B. amyloliquefaciens, but in case of S. cerevisiae transformant, the amylase secreted was not detected. A comparison of genetic stability of pEA24 and YRp7 plasmids in yeast was carried out by cultivation of transformants in tryptophan-supplement-medium. The pEA24 plasmid was more unstable than YRp7 in S. cerevisiae. The size of pEA24 extracted from S. cerevisiae transformants was found to be identical with that from E. coli transformants by agarose gel electrophoresis.

• Journal of Korean Society of Forest Science
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• v.73 no.1
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• pp.21-32
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• 1986

This study was done to classify 15 species in the genus Acer through tracking of the changing shape of the vascular branch from the base part to the terminal part of petiole by the anatomical method. The basic vascular branches were 3 ea, except A. mandshuricum 3-4 ea. The vascular bundle was separated, moved and connected from the base part to the terminal part of petiol, the number of separated vascular branch was 11-32 ea., the number of connected vascular branch was 0-17 ea., and the ratio of the separated vascular branch to the connected was 0.00-8.00. The maximum number of vascular branch in No, 39 of cross section part was observed in 12 species; A. ginnala and A. buergerianum were No. 11, A. truncatum and A. platanoides were No. 13, A. saccharium was No. 26. The number of the connected vascular branches with the main vascular branch were 0-6, while the number of the separated vascular branch were 0-7. On the ratio of separation to connection of the base vascular branch; "A", "B" and "C", the symmetrical shapes on the basis of "B" were A>BC, AB>C shape. The classical groups by the development of main vascular branch formation were obtained 7 groups of "a" through "g" shape. Especially, A. negundo and A. saccharinum were shown to have central vascular branches with unique changing patterns.

• Journal of Life Science
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• v.24 no.4
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• pp.386-392
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• 2014

Haw (Crataegus pinnatifida $B_{UNGE}$) is a medicinal plant commonly used in Korea due to its beneficial health effects. This study was performed to investigate the antioxidative activity of bioactive components from haw seed. Freeze-dried seed was processed with various solvents such as 70% methanol, 70% ethanol, a mixture of chloroform and methanol (2:1, v / v), n-butanol and ethyl acetate (EA). DPPH, reducing power, ferric reducing antioxidant power (FRAP), and ABTS radical scavenging activity decreased in this order: 70% methanol, 70% ethanol, EA, CM, n-butanol extracts. NO radical scavenging activity was high in the n-butanol extract (36.73% in 0.8 mg/ml concentration) and low in the 70% ethanol extract (24.96% in 0.8 mg/ml concentration). $OH^-$ radical scavenging activity of n-butanol extract (40.42% in 0.8 mg/ml concentration) was higher than the other extracts, but EA extract was the lowest (13.39%) at the same concentration. The results show that each extract contained various antioxidative substances and it seemed that different influence at each antioxidative activity.

• Atmosphere
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• v.15 no.3
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• pp.149-153
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• 2005

A balloon-borne Optical Particle Counter (hereafter "OPC Sonde"), which was developed by the atmospheric research group of Nagoya University, is used for getting the information of vertical profile of particle size and concentration in Anmyeon ($36^{\circ}32^{\prime}N$ $126^{\circ}19^{\prime}E$) on 18 March 2005. A range of five different particle sizes is shown in the vertical profile of aerosol number density estimated from the OPC Sonde. It was found that small size particles have vertically larger aerosol number density than relatively big ones. For all size ranges the vertical aerosol number density shows a decreased pattern as the altitude becomes higher. The aerosol number density of $0.3{\sim}0.5{\mu}m$, $0.5{\sim}0.8{\mu}m$, $0.8{\sim}1.2{\mu}m$ size ranges at the 10km height, which is the tropopause approximately, are $1,000,000ea/m^3$, $100,000ea/m^3$, $10,000ea/m^3$ respectively. The data of OPC Sonde are also compared with the data of PM10 $\beta$-ray) and Micro Pulse Lidar which are operating at Korea Global Atmosphere Watch Observatory in Anmyeon.

• Korean Journal of Veterinary Research
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• v.29 no.4
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• pp.525-530
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• 1989

In order to enumerate the T-lymphocytes in bovine peripheral blood lymphocytes (PBL) by E rosette assay, KGRBC were treated with various concentrations of 2-aminoethylisothiouronium bromide(AET) and dextran(Dex), singly or in combination. To further standardize the assay, optimum concentration of AET- and/or Dex-treatment and incubation time for rosette forming cell(RFC) counts were determined. The levels of B-lymphocytes in the PBL were evaluated by erythzocyte-antibody($EA_{Fc}$)- and erythrocyte-antibody-complement (EAC)-rosetting techniques. The results obtained were as follows; The PBL from 20 clinically normal Korean cattle were formed as low percentage of spontaneous E-rosette ($6.7{\pm}2.4%$) in control group, whereas in KGRBC treated with 0.1M AET for 20 minutes and 8% Dex were formed as $37.3{\pm}2.7%$ and $45.1{\pm}2.1%$, respectively. And the synergistic effects were noted no less than $66.5{\pm}5.6%$ when the KGRBC treated with 0.1M AET and 8% Dex subsequently and rate of RFR did not change significantly between 3~24 hours incubation time at $4^{\circ}C$, EA-and EAC-RFR were $23.3{\pm}9.1%$ and $23.1{\pm}7.9%$, respectively. These results suggest that the KGRBC would be a useful agent for the enumeration of T-lymphocytes by E rosette assay and B-lymphocytes by EA- or EAC-rosette assay in cattle-PBL.

• Biomolecules & Therapeutics
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• v.13 no.3
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• pp.150-155
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• 2005

The ethanolic extract of chestnut (Castanea crenata S. et Z., Fagaceae) inner shell (CISE) and one of its components, ellagic acid (EA), were evaluated for their protective effects against 1, 1-diphenyl-2-picryl hydrazine (DPPH) free radical generation and hydrogen peroxide-induced oxidative DNA damage in a mammalian cell line. CISE and EA were shown to possess the free radical scavenging effect against DPPH radical generation, significantly. They were also found to strongly inhibit hydrogen peroxide-induced DNA damage from Chinese hamster lung (CHL) cell, assessed by single cell gel electrophoresis assay and 8-hydroxy -2'-deoxy guanosine (8-OH-2'dG) assay. Furthermore, topical application of CISE [$12.5\%$(w/w) cream] and ellagic acid [$1.0\%$(w/w) cream] for 14 days potently inhibited malondialdehyde (MDA) formation of mouse dorsal skin (a marker of lipid peroxidation) induced by ultraviolet B exposure. Therefore, CISE and its component, ellagic acid, may be the useful natural antioxidants by scavenging free radicals, inhibition of lipid peroxidation and protecting oxidative DNA damage when topically applied.

• Preventive Nutrition and Food Science
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• v.8 no.4
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• pp.390-394
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• 2003

In the post-genome period, the technique for identifying gene expression has been progressed to high throughput screening. In the field of molecular nutrition, the use of screening techniques to clarify molecular function of specific nutrients would be very advantageous. In this study, we have evaluated Zn-regulated gene expression in Zn-deficient, homocystein-treated EA.hy926 cells, using cDNA microarray, which can be used to screen the expression of many genes simultaneously. The information obtained can be used for preliminary assessment of molecular and signaling events modulated by Zn under pro-atherogenic conditions. EA.hy926 cells derived from human umbilical vein endothelial cells were cultured in Zn-adequate (control, 15 $\mu$M Zn) or Zn-deficient (experimental, 0 $\mu$M Zn) Dulbecco's MEM media under high homocysteine level (100 $\mu$M) for 3 days of post-confluency. Cells were harvested and RNA was extracted. Total RNA was reverse-transcribed and the synthesized cDNA was labeled with Cy3 or Cy5. Fluorescent labeled cDNA probe was applied to microarray slides for hybridization, and the slide was then scanned using a fluorescence scanner. The expression of seven genes was found to be significantly decreased, and one significantly increased, in response to treatment of EA.hy926 cells with Zn-deficient medium, compared with Zn-supplemented medium. The upregulated genes were oncogenes and tumor suppressor genes, cell cycle-related genes and transporter genes. The down-regulated gene was RelB, a component of the NF-kappaB complex of transcription factors. The results of this study imply the effectiveness of cDNA microarray for expression profiling of a singly nutrient deficiency, namely Zn. Furthur study, using tailored-cDNA array and vascular endothelial cell lines, would be beneficial to clarify the molecular function of Zn in atherosclerosis, more in detail.

• Korean Journal of Soil Science and Fertilizer
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• v.8 no.2
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• pp.69-80
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• 1975

Relationships between yield and various nitrogen efficiencies, between efficiencies and between efficiency and nitrogen uptake amount of rice plant were proposed and tested using data from N.P.K simple trials about 30 to 50 locations, for three years. Established relationships are well in accordance with experimental results by showing highly significant correlations between them. The overall indications are that high yielding capacity of fields with fertilizer application, depends primarily on high fertilizer nitrogen uptake by increasing fertilizer use efficiency (Eu), secondly the efficiency (Ef) of absorbed fertilizer nitrogen (Nf) and fertilization efficiency (Fe) and also depends much on nitrogen efficiency for grain yield (E) to great extend and that the efficiency (Es) of soil nitrogen (Ns) contributes to E more than Ef does. All nitrogen efficiencies are negatively correlated with the uptake amount of corresponding nitrogen and counterpart efficiency. Es and Ef could be determined firstly by difference method and secondly E versus Cs (Cs=Ns/Ns+Nf) plotting and thirdly E-Cs plotting with labelled fertilizermethod using the equation E=Es Cs+B where B=Ef Cf but a constant under the given condition and at last Y-Ns plotting with labelled fertilizer using Eq Y=$Es{\cdot}Ns+B$ where B=$Ef{\cdot}Nf$. Es which seems not much variable from field to field is mostly greater (about 80% of tested fields) than Ef which is much variable and depends much on fertilizer form. The relationships tested and well agreed are as follows: 1. Y=$Es{\cdot}Ns+Ef{\cdot}Nf$ (Y is yield) 2. E=$Es{\cdot}Cs+Ef{\cdot}Cf$ where Cf=Nf/Nf+Ns 3. E=b-aN where E=E, Es or Ef and N=N, Ns or Nf respectively, (E=Y/N, N=Nf+Ns), b is theoretical maximum under the given system and a is tangent at N=O of the curve, Y=EN. 4. Fe=Ef Eu and Se=$Es{\cdot}Eu$ where Se is efficiency of soil available nitrogen. 5. E=$(Se{\cdot}Cs+Fe{\cdot}Cf)/Eu$ 6. Y=$Es{\cdot}Eu{\cdot}Sf+Ef{\cdot}Eu{\cdot}Fn$or Y=$Es{\cdot}Eu{\cdot}Ea{\cdot}Sn+Ef{\cdot}Eu{\cdot}Fn $where Sf=$Ea{\cdot}Sn$, Ea is soil available nitrogen equivalent to fertilizer(Sf) divided by total soil nitrogen (Sn).

• Advances in pediatric surgery
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• v.9 no.1
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• pp.6-11
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• 2003

This study reviews 14 years' experience treating esophageal atresia with special emphasis on the clinical profile and outcome. From May 1989 to February 2003, 65 cases of esophageal atresia (EA) were treated at Asan Medical Center. Boys outnumbered girls 2.4 to 1. Prematutity and low birth weight were 27.7% and 38.5%. Esophageal atresia with distal tracheoesophageal fistula (TEF) was the most common type (87.7%), followed by pure EA and H type fistula. Forty-six patients (70.8%) had one or more associated anomalies, cardiac malformations were the most common. Duodenal atresia was found in 7 cases. There were 6 patients (9.2 %) with VATER cluster. VACTERL cluster was present in 18 patients (27.7%), one of who fulfilled the complete syndrome. Waterston group A, B and C made up 21.5%, 40.0% and 38.5% of the total group. Surgical treatment was attempted in 63 patients and deferred in 2 who had severe associated malformations. For EA with distal TEF, primary esophago esophagostomy was carried out in 51 cases, and division of TEF and gastrostomy in 4 cases and no operation in 2 cases. For pure EA, colonic graft was done in 2 after gastrostomy and esophagostomy, and esophago esophagostomy was performed in 2 after gastrostomy. Two patients with pure EA are waiting for the second operation after gastrostomy. Division of TEF was carried out in 2 cases with H type TEF. The overall survival rate was 76.9%, and survival by Waterston classification was 100% in group A, 80.8% in B and 60.0% in C. Thorough workup for associated anomalies, interdepartmental approach and more careful surgical decision and technique are required to improve the outcome of EA.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.1
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• pp.231-238
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• 2019

In this paper, we have studied how to improve the amplifiers efficiency by minimizing the combining loss when several unit power amplifiers are combined to obtain high output power. Specifically, we have developed Ka-band Spatial Combining Amplifier. The fabricated Spatial Combining Amplifier is a Ka-band 20W class SSPA, which uses a 5W class unit amplifier module 8EA designed using a GaN bare die. We also combined The unit amplifier module using 8-way spatial divider and combiner with a hybrid radial structure. The output combining loss of the fabricated spatial coupler is about 0.334dB, which is about 92.6% efficiency. In this paper, we developed a Spatial Combining Amplifier with a maximum saturation output of 10W and a power addition efficiency of over 15%. As a result, we achieved the maximum saturation output of 30W and the power addition efficiency of 19%.