• Journal of Embryo Transfer
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• v.32 no.3
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• pp.165-170
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• 2017

Pigs have been extensively used as mediators of xenotransplantation research. Specifically, the Massachusetts General Hospital (MGH) miniature pig was developed to fix major histocompatibility antigens for use in xenotransplantation studies. We generated transgenic pigs for xenotransplantation using MGH pigs. However, it has not been studied yet whether these pigs show similarity of reproductive physiological characteristics to wild types of MGH miniature pig. In this study we analyzed the estrous cycles and pregnancy characteristics of wild type (WT) and transgenic MGH miniature pigs, which were ${\alpha}1,3$-galactosyltransferase (GalT) heterozygous and homozygous knock-out, and membrane cofactor protein (MCP) inserted in its locus, $GalT^{-MCP/+}$ and $GalT^{-MCP/-MCP}$ pigs. Estrous cycles of WT, $GalT^{-MCP/+}$ and $GalT^{-MCP/-MCP}$ pigs were $20.9{\pm}0.74$, $20.1{\pm}1.26$, and $17.3{\pm}0.87days$, respectively, and periods of estrous were $3.2{\pm}0.10$, $3.1{\pm}0.12$, and $3.1{\pm}0.11days$. The periods of gestation of WT, $GalT^{-MCP/+}$ and $GalT^{-MCP/-MCP}$ pigs were $114.2{\pm}0.37$, $113.3{\pm}0.67$, and $115.4{\pm}0.51days$, respectively. Litter sizes of WT, $GalT^{-MCP/+}$ and $GalT^{-MCP/-MCP}$ pigs were $4.8{\pm}0.35$, $4.8{\pm}1.11$ and $3.0{\pm}0.32$ respectively. There were no significant differences on estrous cycle, periods of estrous and gestation, and litter size among WT, $GalT^{-MCP/+}$ and $GalT^{-MCP/-MCP}$ pigs, meaning that GalT knock-out and additional expression MCP of the MGH miniature pig did not effect on reproduction traits. These results provide relevant information to establish breeding system for MGH transgenic pig, and for propagation of $GalT^{-MCP/-MCP}$ pig to supply for xenotransplantation research.

• Journal of the Korean Ceramic Society
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• v.31 no.12
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• pp.1429-1436
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• 1994

We have prepared Ba0.5Sr0.5TiO3 thin films on Si substrate without buffer layer. Deposition was carried out by off-axis rf magnetron sputtering method using Ba0.5Sr0.5TiO3 stoichiometric target. The substrate temperature was changed from 40$0^{\circ}C$ to $700^{\circ}C$ during deposition. As the substrate temperature increased, relative intensity of (110) peak increased up to $600^{\circ}C$, however preferred orientation changed from (110) to (h00) beyond $650^{\circ}C$ of substrate temperature. Deposited films showed microstructures with fine grains whose diameters are less than 100 nm, and columnar structure was observed in the cross-sectional SEM micrograph. AES depth profile showed no significant diffusion at the interfacial reaction area. The effective dielectric constant of films showed maximum value at $600^{\circ}C$, and the leakage current increased with increasing substrate temperature, which may be ascribed to the crystallization of amorphous phases at grain boundary.

• Journal of the Korean Electrochemical Society
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• v.10 no.3
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• pp.207-212
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• 2007

[ $PSCF3737(Pr_{0.3}Sr_{0.7}Co_{0.3}Fe_{0.7}O_3)$ ] is a good candidate cathode material for IT-SOFC(intermediate temperature solid oxide fuel cell) because of high MIEC(mixed ionic electronic conductor) conductivity. In this study, the characteristics of PSCF3737 was investigated and optimizations of sintering temperature and thickness for $PSCF3737(Pr_{0.3}Sr_{0.7}Co_{0.3}Fe_{0.7}O_3)$ was carried out. Impedance responses were divided into two parts by frequency region. Middle frequency part (${\sim}10^2\;Hz$) was concerned with oxygen reduction reaction on surface and low frequency part (${\sim}10^{-1}\;Hz$) was related with oxygen diffusion. The reasonable sintering temperature and thickness of cathode were $1200^{\circ}C$ and about $27\;{\mu}m$ with regard to EIS(electrochemical impedance spectroscopy). ASR(areas specific resistance) of optimized cathode is $0.115\;{\Omega}\;cm^2$ at $700^{\circ}C$.

• Journal of The Korean Astronomical Society
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• v.56 no.1
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• pp.1-9
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• 2023

The Crab nebula is widely used as a polarization angle calibrator for single-dish radio observations because of its brightness, high degree of linear polarization, and well-known polarization angle over a wide frequency range. However, the Crab nebula cannot be directly used as a polarization angle calibrator for single-dish observations with the Korean VLBI Network (KVN), because the beam size of the telescopes is smaller than the size of the nebula. To determine the polarization angle of the Crab nebula as seen by KVN, we use 3C 286, a compact polarized extragalactic radio source whose polarization angle is well-known, as a reference target. We observed both the Crab nebula and 3C 286 with the KVN from 2017 to 2021 and find that the polarization angles at the total intensity peak of the Crab nebula (equatorial coordinates (J2000) R.A. = 05^h34^m32.3804^s and Dec = 22°00'44.0982'') are 154.2° ± 0.3°, 151.0° ± 0.2°, 150.0° ± 1.0°, and 151.3° ± 1.1° at 22, 43, 86, and 94 GHz, respectively. We also find that the polarization angles at the pulsar position (RA = 05^h34^m31.971^s and Dec = 22°00'52.06'') are 154.4° ±0.4°, 150.7° ±0.4°, and 149.0° ± 1.0° for the KVN at 22, 43, and 86 GHz. At 129 GHz, we suggest to use the values 149.0° ± 1.6° at the total intensity peak and 150.2° ± 2.0° at the pulsar position obtained with the Institute for Radio Astronomy in the Millimeter Range (IRAM) 30-meter Telescope. Based on our study, both positions within the Crab nebula can be used as polarization angle calibrators for the KVN single-dish observations.

• Journal of Animal Science and Technology
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• v.54 no.5
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• pp.349-354
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• 2012

In this experiment, two inclusion levels (15 and 30% of diets, as-fed basis) of brown rice (BR) were tested against a control diet with 0% BR (51% wheat flour of diet). Six female Miniature Poodles (8~9 months age, initial mean body weight of 3.5 kg) were assigned to treatments in replicated $3{\times}3$ Latin square design. Total tract digestibilities of DM, OM, CP, acid hydrolyzed fat and gross energy increased linearly (P<0.05), and observed digestible energy and metabolizable energy values also increased linearly (P<0.001 and P=0.007, respectively) with increasing BR inclusion levels. Wet and dry fecal output decreased linearly (P=0.001) with increasing BR inclusion levels in the diets. Linear (P<0.05) effects was observed in fecal score for dogs fed BR and fecal ammonia concentration increased linearly (P<0.05) in response to increasing BR inclusion level. It seems that the increase in fecal ammonia concentration may be partially related to the decrease in short-chain fatty acid concentration (P<0.01). This study clearly demonstrates that BR improves nutrients digestibility and fecal characteristics of dog.

• Journal of agriculture & life science
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• v.50 no.5
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• pp.129-137
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• 2016

This study investigated the effect of dietary lysine and gamma-linolenic acid(GLA) levels on growth performance, carcass traits, and meat quality in finishing pigs. Pigs were provided with feed containing two different levels of lysine(0.45% and 0.75%) with three different levels of gamma-linolenic acid(0.0, 0.3, and 0.6%). Average daily gain(ADG) was significantly lower (p<0.01) in pigs provided with the lower level of lysine. In contrast, feed/gain(p<0.01), diet cost/gain(p<0.05), and intramuscular fat(p<0.01) were all significantly higher in pigs fed the lower level of lysine. Similarly, meat color scores(CIE L*, a*, and b*) and cooking loss were significantly higher(p<0.01) in pigs fed the lower level of lysine, whereas shear force(kg/2.5 inch2)was not affected by dietary lysine. The addition of GLA had no significant effect on any of the parameters measured. The results indicate that providing pigs with 0.45% lysine in their diet may help to increase intramuscular fat content, allowing the industry to produce pork products that meet consumer needs in Korea.

• Korean Journal of Food Science and Technology
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• v.15 no.2
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• pp.164-169
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• 1983

The triglyceride composition of perilla oil was investigated by high performance liquid chromatography (HPLC) in combination with gas liquid chromatography (GLC). The triglycerides were separated from perilla oil by thin layer chromatography (TLC), and fractionated into five groups on the basis of their partition numbers by reverse phase HPLC on a column packed with ${\mu}-Bondapak\;C_{18}$ using methanol-chloroform mixture as a solvent. Each of these collected fractions gave one to three peaks in the GLC chromatograms according to the acyl carbon number of the triglyceride, and fatty acid composition of the triglyceride was also analyzed by GLC. The results indicate that the perilla oil consists of fifteen kinds of triglycerides, and the major triglycerides in perilla oil were as follows: 68.0% of $(C_{18:3},\;C_{18:3},\;C_{18:3})$, 6.7% of $(C_{18:2},\;C_{18:3},\;C_{18:3})$, 5.9% of $(C_{18:1},\;C_{18:3},\;C_{18:3})$, 4.3% of $(C_{16:0},\;C_{18:3},\;C_{18:3})$, 3.8% of $(C_{18:1},\;C_{18:2},\;C_{18:3})$, 3.2% of $(C_{18:1},\;C_{18:1},\;C_{18:3})$, 2.0% of $(C_{16:0},\;C_{18:2},\;C_{18:3})$, 1.5% of ($C_{18:2},\;C_{18:2},\;C_{18:3})$, 1.0% of $(C_{16:0},\;C_{18:1},\;C_{18:3})$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.3
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• pp.274-282
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• 2014

We examined seasonal variation in the structure of marine macroalgal communities at five sites around the Byeonsan Peninsula, Korea, from January to October 2011. Sixty eight species were identified, including 11 green, 17 brown and 40 red algae. Species richness was highest at Gyeokpo (51 species) followed by Sambal (47), Gosapo (34), Byeonsan (33), and Habgoo (18). Seaweed biomass ranged from 12.98 to 145.33 g dry $wt/m^2$, with maximum and minimum biomasses at Gyeokpo and Habgoo, respectively. Sargassum thunbergii was the representative alga species occupying 47.89% of the total biomass. The dominant seaweeds were S. thunbergii, Corallina pilulifera, Ulva spp, Gracilaria vermiculophylla, and Carpopeltis affinis. No distinctive vertical distribution of seaweeds was found because S. thunbergii, Ulva spp, and G. vermiculophylla were all distributed from high to low shore. Community indices were as follows: dominance index (DI), 0.44-0.61; richness index (R), 6.27-10.35; evenness index (J'), 0.38-0.59; and diversity index (H'), 1.48-1.71. Gyeokpo had the most biomass and highest species richness, and the lowest percentage of Ulva species. However, species richness declined at Gyeokpo, from 78 to 51 species within 10 years, implying that eutrophication and sedimentation from Mankyeong and Dongjin rivers have reduced the stability of seaweed communities.

• Journal of Korean Society of Forest Science
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• v.96 no.4
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• pp.438-447
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• 2007

The purpose of this study was to understand the ecosystem structure and function and soil water changes in Tricholoma matsutake producing pine stands. The investigated stands were pine forest in Sogrisan National Park in Chungbuk-do of Korea. For the purpose we investigated main vegetation, leaf area index(LAI) as ecosystem structural factors and measured photosynthesis, transpiration, xylem water potential, and soil water changes as ecosystem functional factors. Vertical vegetation structure of the site was composed of Pinus densiflora as a overstory species, Quercus mongolica as midstory, Rhododendron mucronulatum, R. schlippenbachii and Fraxinus sieboldiana as understory ones. In the stands LAI was 3.8 during June to September, 2.6 in October and 2.1 during November to April. Photosyntheses of the trees were 6.0 to $7.0{\mu}mol\;CO_2/m^2/s$ in August, and for P. densiflora about $4.0{\mu}mol\;CO_2/m^2/s$ and for Q. mongolica $2.0{\mu}mol\;CO_2/m^2/s$ in mid October. However, R. mucronulatum stopped fixing $CO_2$ and F. sieboldiana shed off the leaves already in mid October. Transpirations were 2.5 to $3.5mmol\;H_2O/m^2/s$ in late August and about $1.0mmol/H_2O/m^2/s$ in mid October. Plant water potentials were -10 to -22 bars for P. densiflora and -5 to -12 bars for the other woody species. The lowest potentials was in late August and highest in late October. Soil water in the stand was closely related to topography. Soil water contents were 7 to 11% at the ridge, 8 to 15% at the hillside and 11 to 19% at the base. Soil temperatures were 0.2 to $0.4^{\circ}C$ higher in T. matustuake colony than noncolony. Mid September soil temperature decreased to $19^{\circ}C$ at which T. matsutake forms primordia. In T. matsutake colony soil moisture was 0.5 to 2.0% lower due to metabolism for consuming water. We suggest that the complicate relationships between ecosystem structure and function in Tricholoma matsutake producing pine stand need to be further investigated.

• Preventive Nutrition and Food Science
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• v.3 no.3
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• pp.216-220
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• 1998

Lipoxygenase inhibitory acitivity of the methanolic extract of 60 different kinds of plant seeds was determined by a spectrophotometric method using a soybean lipoxigenase(SLO) and linolenic acid. Among the extracts examined, the methanolic extract of nutmeg(Myristical fragrans)seed showed the most potent SLO inhibitory activity. To isolate SLO inhibitor, hence, the defatted methanol extract was further partitioned with ether, ehtylacetate , and n-butanol , stepwise. The ether souble fraction was successively chromatographed on silica gel, Sephadex LH-20 and preparative TLC. Three phenolic compounds were isolated , and one of them showing a strong SLO inhibition activity was identified as a 2,6-dihydroxy-9-(3', 4', -dihydroxyphenyl)nonylphenone (IC50a=0.39$\mu\textrm{g}$/ml) by 1H-& 13C0NMR, IR, and MS spectroscopy.