• Korean Journal of Microbiology
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• v.30 no.4
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• pp.305-309
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• 1992

Cytosine deaminase (EC 3.5.4.1) from BaciNus stc~urorhermophilus was partially purified 7.2-fold with an overall yield of 52.7%. The partially purified enzyme deiiminated cytosine only.but not 5-methylcytosine and 5-fluorocytosine. The apparent Michaclis constant. Km valuefor cytosine was 5.9 mM. The enzyme was relatively stable in the range of pH 4.0 to 7.0.furthermore extremely thermo-stable : more than 75'X) of the activity was remained afterheating at 80$^{\circ}$C for I0 min at pH 6.5. The enzyme had a pH optimum at around pH7.0 to 7.5. and temperature optimum at 35 to 31$^{\circ}$C. And the activation energ (En value)determined from an Arrhenius plot was 26 Kcal/mol. The enzyme activity was stronglyinhibited by heavy metal ions such as Cd", Hg". Cut' at 1 mM, anJ by o-phenanthroline,and p-chloromcrcuribcnzoate at I mM. But the enrymc activity was activatetl increased byGMP, and CMP at 1 mM.ased by GMP, and CMP at 1 mM.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.4
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• pp.435-444
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• 2014

This study was carried out to isolate and characterize the flavonoids present in corn silks. Maysin content in the unpollinated corn silks (Kwangpyeongok) showed its highest level at 3 days after silking, and decreased thereafter, while the content of open pollinated silks were consistently decreased after silking. This result indicates that the maysin content is considerably affected by the pollination of corn silk. Unpollinated corn silks were collected with excising, and ethanol employed to extract flavonoids at common temperature for 9 days. After extraction, chlorophyll, lipids etc. were removed with methylene chloride, then submitted to flash column cartridge ($150{\times}40mm$ i.d.) packed with a preparative $RP-C_{18}$ bulk packing material ($125{\AA}$, $55-105{\mu}m$), and monitored at 352 nm. Four fractions, fraction-I, -II, -III, and -IV, were isolated from ethanolic extract of corn silks. Absorption spectrum of fraction I showed its maximum intensity (${\lambda}_{max}$) at 327 nm and 239 nm, fraction-II showed its maximum intensity at 339 nm and 274 nm, fraction-III showed its maximum intensity at 345 nm and 277 nm, and fraction-IV showed its maximum intensity at 352 nm, 270 nm, 257 nm, respectively. On the baisis of ESI micro-TOF analysis, fraction-I was identified as chlorogenic acid (m/z 355, 3-(3,4-dihydroxycinnamoyl) quinic acid, $C_{16}H_{18}O_9$), fraction-II identified as a mixture of chlorogenic acid and luteolin 3'-methyl ether 7-glucuronosyl-($1{\rightarrow}2$)-glucuronide (m/z 653, $C_{28}H_{28}O_{18}$), fraction-III identified as a mixture of chlorogenic acid luteolin 7-O-neohesperidoside (m/z 595, $C_{27}H_{30}O_{15}$), and luteolin 3'-methyl ether 7-glucuronosyl-($1{\rightarrow}2$)-glucuronide, and fraction-IV identified as maysin (m/z 577, 2"-O-${\alpha}$-L-rhamnosyl-6-C-(6-deoxy-xylohexose-4-ulosyl)luteolin, $C_{27}H_{28}O_{14}$), respectively. From the ethanolic extract of corn silks, fraction-I was obtained about 35 mg/100 g F.W., fraction-II was about 48 mg/100 g F.W., fraction-III was about 46 mg/100 g F.W., and fraction-IV was about 138 mg/100 g F.W., respectively.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.19 no.3
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• pp.215-222
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• 2014

Paralarvae of the common squid, Todarodes pacificus Steenstrup were sampled with the bongo net (diameter: 60 cm, mesh: $333{\mu}m$) by using oblique tow method with the oceanographic research vessel (Tamgu 12) at 21 stations along the southwestern coastal waters of the East Sea in August and September, 2013. Paralarvae were collected 16 ind./$10m^3$ in August and 7 ind./$10m^3$ in September at approximately, and bottom depth was from 70 m to 500 m. Mantle length of paralarvae was from 1.7 to 6.0 mm. Paralavae were distributed mainly in offshore stations in August and near by Cape Janggi in September. Optimum embryo survival temperature ($18-24^{\circ}C$) was formed shallower than 35 m depth for almost stations where paralarvae were existed, and survival temperature ($15-24^{\circ}C$) for embryo stage was located shallower than 75 m.

• Korean Journal of Materials Research
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• v.10 no.3
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• pp.204-211
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• 2000

The $(Y,Gd)BO_3:Eu$ red phosphors for PDP application were synthesized by ultrasonic spray method and then their photoluminance properties were investigated under 147nm VUV irradiation. The precursor solution of acetates of Y, GD and Eu and boric acid diluted in water was sprayed using 1.7 MHz ultra-sonic sprayer into the reaction tube held at high temperature. The as-sprayed particles were amorphous phase having C-C and C-H bonds due to the insufficient thermal reaction during the pass along the tube. But the sprayed samples followed by heat treatment at $1100^{\circ}C$ had the same crystal structure and chemical composition as those samples followed by solid state reaction. It was found that the $(Y_{0.7}Gd_{0.3})_{0.95} BO_3:Eu_{0.05}^{3+}$ phosphor particles synthesized by spray at $500^{\circ}C$ and then heat treated at $900^{\circ}C$ had a spherical-like shape and fine particle size at $0.7{\mu\textrm{m}}$ having a narrow size distribution, while the phosphor particles made by solid state reaction was $3{\mu\textrm{m}}$ coarse and non-uniform size distribution. The emitting intensity under 147nm VUV excitation for $(Y_{0.7}Gd_{0.3})_{0.95}BO_3:Eu_{0.05}^{3+}$ phosphor prepared by spray method was found to be higher than those phosphor made by solid state reaction and the commercial $(Y,Gd)BO_3:Eu$ product.

• Electrical & Electronic Materials
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• v.8 no.2
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• pp.224-228
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• 1995

0.15(B $a_{0.95}$ S $r_{0.05}$)O-0.15S $m_{2}$ $O_{3}$-0.7Ti $O_{2}$ ceramics were fabricated by the mixed-oxide method. Microwave dielectric properties were investigated with sintering conditions. Increasing the sintering temperature from 1300 to 1375[.deg. C], the sintered density was increased from 5.44 to 5.63[g/c $m^{3$]. Increasing the sintering temperature, dielectric constant and quality factor were increased and temperature coefficient of resonant frequency was independent of sintering temperature. In the specimen sintered at 1375[.deg. C], dielectric constant, quality factor and temperature coefficient of resonant frequency were 80.79, 2784(at 3[GHz]), +11.07[ppm/.deg. C], respectively..

• The Korean Journal of Mycology
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• v.10 no.2
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• pp.67-73
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• 1982

The $(NH_4)_2\;SO_4$ (70%) treated crude enzymes from the culture filtrates of the$C-7^{+t}$ strain of Pyricularia oryzae which was grown on 2% CMC (carboxymethyl cellulose) for 8 days at $28^{\circ}C$ were chromatographied on Sephadex G-150 and DEAE-Sephadex A-25 columns. From the chromatography, three fractions of CMCase$(C_x)$ was examined using Na-CMC as substrate. The $C_x$ enzyme activity was optimal at pH 6.0 and $40^{\circ}C$, stable up to $40^{\circ}C$. The values of Km and Vmax of the enzyme were $2.8{\times}10\;mM$ and 5.9m moles/hour, respectively. The molecular weight determined by Sephadex G-150 column chromatography was around 80,000. Approximately sevenfold purified $C_x$ enzyme gave a single protein band on the polyacrylamide gel electrophoresis.

• Korean Journal of Animal Reproduction
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• v.16 no.2
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• pp.117-123
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• 1992

This Study was carried out ot investigate the effects of concentration and equilibration time of cryoprotective aagents on survival rate of slowly and ultrarapidly frozen porcine embryos. The porcine embryos following dehydration by cryoprotective agents and 0.25M sucrose were slowly freezed(from 2$0^{\circ}C$ to -7$^{\circ}C$/-1$^{\circ}C$/min., from -7$^{\circ}C$ to -35$^{\circ}C$/-0.2$^{\circ}C$/min., from -35$^{\circ}C$ to -38$^{\circ}C$/-0.3$^{\circ}C$/min.) by Cell Freezer and directly plunged into liquid nitrogen and thawed in 38$^{\circ}C$ water bath. Survival rate was defined as development rate to the morula and blastocyst stage after in vitro culture or by FDA test. The results are summarized as follows : 1. The survival rates of porcine embryos after slow frozen-thawing in the freezing medium of 0.25M sucrose added 2.0M glycerol, 3.0M DMSO, 2.0M propanediol or 2.0M glycerol＋2.0M propanediol was 80.6, 84.7, 75.0 or 78.8%, respectively. 2. The survival rates of porcine embryos after slow frozen-thawing in the freezing medium of 0.50M sucrose added 2.0M glycerol, 3.0M DMSO, 2.0M propanediol or 2.0M glycerol＋2.0M propanediol was 80.9, 82.4, 73.1 or 77.1%, respectively. 3. The survival rates of porcine embryos after ultrarapid frozen-thawing in the freezing medium of 0.25M sucroese added 2.0M glycerol, 3.0M DMSO, 2.0M propanediol or 2.0M glycerol＋2.0M propanediol was 65.3, 68.6, 63.2 or 59.9%, respectively. 4. The survival rates of porcine embryos after ultrapid frozen-thawing in the freezing medium of 0.50M sucrose added 2.0M glycerol, 3.0M DMSO, 2.0 propanediol or 2.0M glycerol＋2.0M propanediol was 67.5, 62.9, 56.9, or 62.8%, respectively. 5. The higher survival rate of porcine embryos was attained at the short period ofequilibration time(5min.) in the freezing medium added 0.25M sucrose and 3.0 DMSO compared to those of 10 or 20min. equilibration time in the same condition.

• Korean Journal of Microbiology
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• v.30 no.4
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• pp.239-245
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• 1992

Buci1llr.s 11c~h~n~1rnSiSi.As 3-2MI which is responsible for the special taste of traditionalKorean soy sause produced two kinds of proteinase. The activity of the proteinasc I washigher about two fold than that of proteinase 11. The optimai, reaction pH of proteinaseI and I1 wcre found to be 7-1 1.5 and 7-9. respectively. Proteinase I1 was more stable andactive than proteinase I at pH ranges around 3 to 5. The optimal te~tlperature of proteinaseI and I1 were 502. The temperature stabilitl of proteinase I1 was Inore stable thanproteinase 1 at temperature range around 30-quot;~A. ctivities of proteinase I and I1 graduallydeclined above $30^{\circ}$C and 45C. respectively. Proteinasc 1 was more active than proteinaseI1 at salt concentration range around 25-3500. The K,,, values of casein and soy proteinfor proteinase I were 6.89 mglml and 3.98 mglml. In case of proteinase 11. they were 9.00mgiml anti 11.44 111g/ml. respectively. The activity of the crudc enzyme was increased by1 rnM Pb(CH3COO). but was decreased by 5 n1M and 10 rnM of HgS04 and ZnS04. Thetwo proteinases produced amino acids and peptides from the soybean protein. The peptideswere digested into amino acids. Both protcinases were found to be the main enzymes thatproduced amino acids which make the main taste of traditional Korean soy sauce.al Korean soy sauce.

• Journal of The Korean Society of Grassland and Forage Science
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• v.36 no.1
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• pp.1-6
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• 2016

The growth of Italian ryegrass (IRG) after wintering was very low in 2015 when IRG was broadcasted under growing rice in fall of 2014. To determine growth inhibitory factors of IRG, we examined the growth conditions of IRG in Nonsan region and meteorological conditions in Daejeon nearby Nonsan. Minimum temperature and maximum instantaneous wind speed on Feb. $8^{th}$ and $9^{th}$ of 2015 after wintering of IRG were $8.8^{\circ}C$, 10.7 m/s and $12.4^{\circ}C$, 9.6m/s, respectively. Air temperature was suddenly dropped due to strong wind with snow showers, which had unfavorable effect on root growth of IRG exposed at the soil surface. The minimum temperature and maximum instantaneous wind speed on Feb. $12^{th}$, $13^{th}$, and $14^{th}$ of 2015 were $4.1^{\circ}C$, 11.6 m/s, $-5.6^{\circ}C$, 10.3 m/s, and $-4.7^{\circ}C$, 7.5 m/s, respectively. The growth circumstance of IRG was not good because soil was dried due to drought continued from January. The minimum temperature and maximum instantaneous wind speed on Feb. $26^{th}$, $27^{th}$, and $28^{th}$ of 2015 were $1.8^{\circ}C$, 13.7 m/s, $-3.5^{\circ}C$, 10.6 m/s, and $4.1^{\circ}C$, 6.8 m/s, respectively. The number of wilting of IRG was more than 59% until Mar. $3^{rd}$ of 2015. IRG faced irreparable environment (low minimum temperatures and extreme instantaneous wind speeds) for 9 days from Mar. $4^{th}$ to Mar. $12^{th}$ of 2015. The main reason for the decrease of IRG productivity was collection delay of rice straw after rice harvest because there was continuous rain between Oct. and Nov. of 2014. For this reason, weakly grown IRG under rice straw was withered after wintering. IRG was withered by frost heaving, drought, and instantaneous wind speed in the spring. Furthermore, the root of IRG was damaged while growing in excess moisture in the surface of paddy soil during the winter season due to rain.

• The Korean Journal of Malacology
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• v.26 no.2
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• pp.145-149
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• 2010

The effects of diluents composition on cold storage for Scapharca broughtonii (Schrenck) sperm were examined in the percentage of sperm activity and survival rate. Various diluents of glucose solutions (10 mM Hepes-pH 7.8), 600 mM NaCl, stein solution, Ringer's solution (230 mM NaCl, 8 mM KCl, 2 mM $CaCl_2$, 3.7 mM $MgCl_2$, 0.2 mM $NaHCO_3$, 10 mM Hepes-pH 7.8), 20%, 25% ASW (NaCl 2.7 g + KCl 0.07 g + $CaCl_2$ 0.12 g + $MgCl_2$ 0.46 g + $NaHCO_3$ 0.05 g + distilled water 100 ml) were used to store th sperm at $4^{\circ}C$. The storage effect was evaluated using sperm activity and survival rate. Ringer's solution was found to be better diluents which maintained high activity and survival rate of sperm for a storage period of 7 days. Optimal pH of diluents to store the sperm at $4^{\circ}C$ is 7.5.