• Korean Journal of Soil Science and Fertilizer
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• v.23 no.2
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• pp.152-159
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• 1990

Four active strains, producing siderophore and antagonizing to soil plant disease fungi, were isolated and identified from the wheat rhizosphere to reduce the injurious effects of continuous cropping and study on the biological control. The obtained results were summerized as follow. 1. Four strains of fluorescent Pseudomonas were isolated from the wheat rhizosphere and identified as Pseudomonas fluorescens Biotype A(Ps-1,2,5) and Biotype B(Ps-3) That strains inhibitied growth of R. solani, F.oxysperum and F. solani in vitro 2. Optical density of pigment was maximum at 410nm. 3. Siderophore production by identified strains was decreased with addition of $Fe^{+3}$, although not decreased with addition of $Fe^{+2}$ 4. Pigment of Ps-1, 2 and 3 strain inhibitied growth of R. slani, F. oxysperum and F. solani but pigment of Ps-5 strain did not inhibitie growth of R. solani 5. Effect of inoculation was in order of Ps-2, 1, 5 and 3 strain through the dark culture method, and effect of Ps-1 and Ps-2 was greater than that of treatment of captan 50ppm.

• Journal of Environmental Science International
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• v.17 no.3
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• pp.287-296
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• 2008

A comprehensive quality survey for heavy metals, organophosphorous and organochlorine residual pesticides, and coplanar PCBs in samples such as water, sediments and soils as well as spiders has been implemented. The samples were undertaken at nine stream sites and their vicinity in August 2006, representing different surrounding environments. The levels of PCBs were expressed as concentrations and WHO-TEFs. Among 12 coplanar PCBs as target compounds in this study, 2,3', 4,4', 5-PentaCB (IUPAC # 118) was the congener with the highest concentration. The total concentrations and TEF values of coplanar PCBs in Siheung stream sediment (heavy industrial complex site located in Ansan city) were 3915.50 pg/g and 0.8366 pg-TEQ/g on a dry weight basis, respectively. Such levels were around 40 times higher compared to sediment from Gapyung stream (green site located in the upper of Myunggi mountain). It is probably due to the direct input of PCBs trom PCBs treatment materials. Organophosphorous (EPN, dementon-s-methyl, diazinon, parathion, and phenthoate) and organochlorine (alpha-BHC, aldrin, 4,4'-DDT, 4,4'-DDE, endosulfan alpha and etc.) pesticides were not detected above 5 ppb of detection limits. The concentrations of Cu and Cd in water and sediment samples from Siheung stream were 44.11 and $0.17ug/m\ell$ and $713.42{\mu}g/g$ and $3.73{\mu}g/g$, respectively, which contained $20\sim40$ times higher concentrations than those from Gapyung stream. In addition to the water and sediment samples, the levels of heavy metals in spider from designated sampling sites were also determined. Heavy metals in spider collected near Siheung stream was appeared to be equivalent and/or a little higher levels with respect to other spiders. Furthermore, the ratio of relative heavy metals (Cu, Cd, and Pb) in spider from each stream site showed a correlation as similar as that of heavy metals in soil samples.

• Bulletin of the Korean Chemical Society
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• v.14 no.4
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• pp.439-444
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• 1993

The aerobic oxidation of the Fe(II) complex of 1,4,8,11-tetraazacyclotetradecane, [Fe(cyclam)$(CH_3CN)_2](ClO_4)_2$, in MeCN in the presence of a few drops of $HClO_4$ leads to low spin Fe(III) species [Fe(cyclam)$(CH_3CN)_2](ClO_4)_3$. The Fe(III) cyclam complex is further oxidized in the air in the presence of a trace of water to produce the deep green binuclear bismacrocyclic Fe(II) complex $[Fe_2(C_{20}H_{36}N_8)(CH_3CN)_4](ClO_4)_4{\cdot}2CH_3CN$. The Fe(II) ions of the complex are six-coordinated and the bismacrocyclic ligand is extensively unsaturated. $[Fe_2(C_{20}H_{36}N_8)(CH_3CN)_4](ClO_4)_4{\cdot}2CH_3CN$ crystallizes in the monoclinic space group $P2_1/n$ with a= 13.099 (1) ${\AA}$, b= 10.930 (1) ${\AA}$, c= 17.859 (1) ${\AA}$, ${\beta}$= 95.315 $(7)^{\circ}$, and Z= 2. The structure was solved by heavy atom methods and refined anisotropically to R values of R= 0.0633 and $R_w$= 0.0702 for 1819 observed reflections with F > $4{\sigma}$ (F) measured with Mo K${\alpha}$ radiation on a CAD-4 diffractometer. The two macrocyclic units are coupled through the bridgehead carbons of ${\beta}$-diimitie moieties by a double bond. The double bonds in each macrocycle unit are localized. The average bond distances of $Fe(II)-N_{imine}$, $Fe(II)-N_{amine}$, and $Fe(II)-N_{MeCN}$ are 1.890 (5), 2.001 (5), and 1.925 (6) ${\AA}$, respectively. The complex is diamagnetic, containing two low spin Fe(II) ions in the molecule. The complex shows extremely intense charge transfer band in the near infrared at 868 nm with ${\varepsilon}$= 25,000 $M^{-1}cm^{-1}$. The complex shows a one-electron oxidation wave at +0.83 volts and two one-electron reduction waves at -0.43 and-0.72 volts vs. Ag/AgCl reference electrode. The complex reacts with carbon monoxide in $MeNO_2$ to form carbonyl adducts, whose $v_{CO}$ value (2010 $cm^{-1}$) indicates the ${\pi}$-accepting property of the present bismacrocyclic ligand.

• Journal of Applied Biological Chemistry
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• v.60 no.4
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• pp.383-390
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• 2017

Regarding the facts that fat, which is easily oxidized, is one of the major responsible factors affecting the quality of aroma, and polyphenol compounds including chlorogenic acid (CGA) contribute the anti-oxidative activities to coffee, we investigated fat oxidation, conversion of CGA, and changes of anti-oxidative activities according to the degree of roasting and storage of 60 days. We found that the amount of extractable fat by diethyl ether is increased as the coffee beans are roasted longer. Furthermore, the acidity values of the fat are increased from $8.91{\pm}0.16$ to $17.81{\pm}0.11$, and $10.37{\pm}0.27$ to $17.93{\pm}0.09$ in the medium and dark roasted coffee beans, respectively, while it is increased from $4.47{\pm}0.11$ to $11.89{\pm}0.18$ in the green coffee bean after 60 days. The CGA contents in the coffee beans were decreased from $310{\pm}8.2$ to $282{\pm}11.2$, then to $58{\pm}0.0mg$ in 10 gr of the green, medium and dark beans, respectively, and were not changed significantly during the storage period. However, the anti-oxidative activities measured by 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid radical scavenging assays were not significantly different among the green, medium, and dark coffee beans during the storage period. Furthermore, antioxidant reactive element-luciferase assay showed that biological anti-oxidative activities were increased as coffee beans were more roasted and stored longer. As the total polyphenolic contents in the beans were significantly decreased by roasting, the results suggests that other molecules, such as, Maillard reaction products might play substantial role in anti-oxidative activity and influence cup quality of coffee.

• Applied Chemistry for Engineering
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• v.19 no.5
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• pp.477-483
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• 2008

$La_{0.7}Sr_{0.3}Co_{0.2}Fe_{0.8}O_{3-{\delta}$ oxide was synthesized by a citrate method and a typical dense membrane of perovskite oxide has been prepared using as-prepared powder by pressing and sintering at $1300^{\circ}C$. Precursor of $La_{0.7}Sr_{0.3}Co_{0.2}Fe_{0.8}O_{3-{\delta}$ prepared by citrate method was investigated by TGA and XRD. Metal-citrate complex in precursor was decomposed into perovskite oxide in the temperature range of $260{\sim}410^{\circ}C$ but XRD results showed $SrCO_3$ existed as impurity at less than $900^{\circ}C$. Electrical conductivity of membrane increased with increasing temperature but then decreased over $700^{\circ}C$ in air atmosphere ($Po_2=0.2atm$) and $600^{\circ}C$ in He atmosphere ($Po_2=0.01atm$) respectively due to oxygen loss from the crystal lattice. The oxygen permeation flux increased with increasing temperature and maximum oxygen permeation flux of $La_{0.7}Sr_{0.3}Co_{0.2}Fe_{0.8}O_{3-{\delta}$ membrane with 1.6 mm thickness was about $0.31cm^3/cm^2{\cdot}min$ at $950^{\circ}C$. The activation energy for oxygen permeation was 88.4 kJ/mol in the temperature range of $750{\sim}950^{\circ}C$. Perovskite structure of membrane was not changed after permeation test of 40 h and the membrane was stable without secondary phase change with 0.3 mol Sr addition.

• Journal of the Mineralogical Society of Korea
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• v.6 no.2
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• pp.57-79
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• 1993

Chuncheon nephrite, which was formed by the polymetasomatic alteration of dolomitic marble, can be classified into pale green, green, dark green, and grey types on the basis of their occurrence, mineralogical and textural characteristics. The nephrites consist obiefly of fibrous or hairlike(length/width ratio>10) cryptocrystalline(crystal width < $2{\mu}m$) tremolite, and include less amounts of micro-crystalline diopside, calcite, clinochlore, and sphene as impurities. The oriented and rather curved crystal aggregate, of nephritic tremolite are densely interwoven, resulting in a massive-fibrous texture which may explain the characteristic toughness of nephritic jade. The characteristic greenish color of the nephrite may be preferably related to Fe rather than Cr and Ni. However, the variation of color and tint in the Chuncheon nephrite also depends on the mineralogical and textural differences such as crystallinity, texture, and impurities. The chemical composition of the nephritic tremolite is not stoichiometric and rather dispersed especially in the abundances of Al, Mg, and Ca. Al content and Mg/Ca ratio for the nephritic tremolite are slightly increased with deepening in greenish color of the nephrite. Fe content in the nephritic tremolite is generally very low, but comparatively richer in the dark green nephrite. In nephritic tremolite, wide-chain pyriboles are irregularly intervened between normal double chains, forming a chain-width disorder. Most nephritic tremolites in the Chuncheon nephrite show various type of chain-width defects such as triple chain(jimthompsonite), quintuple chain (chesterite), or sometimes quadruple chain in HRTEM observations. The degree of chain-width disorder in the nephritic tremolite tends to increase with deepening in greenish color. Triple chain is the most common type, and quadruple chain is rarely observed only in the grey nephrite. The presence of pyribole structure in the nephritic tremolite is closely related to the increase of Al content and Mg/Ca ratio, a rather dispersive chemical composition, a decrease of relative intensity in (001) XRD reflection, and an increase in b axis dimension of unit cell. In addition, the degree and variation of chain-width disorder with nephrite types may support that an increase of metastability was formed by a rapid diffusion of Mg-rich fluid during the nephrite formation.

• Korean journal of applied entomology
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• v.47 no.3
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• pp.255-263
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• 2008

A wax-typed pheromone dispenser has been developed and applied to control outbreak of the oriental fruit moth, Grapholita molesta, in apple orchard. To optimize its application technique, this study analyzed effect of different amounts of the pheromone dispenser on mating disruption('MD') of G. molesta. Different pheromone dispenser amounts significantly influenced the MD effect assessed by cumulative male adult catches monitored respectively by sticky delta trap and food trap, and resulted in differential damage on host plants. In a field test during entire growing season, a standard amount(120 g per 0.117 ha) of wax-typed pheromone dispenser was proved to be effective to suppress outbreak of G. molesta adults and to prevent host plant damage as much as a current commercial MD product($Isomate^{(R)}$). This study also demonstrated an effectiveness of deployment of food trap barriers around MD-treated area to prevent immigration of mated females from outside untreated areas. These results indicate that the wax-typed pheromone dispenser can be applied to control field G. molesta populations and its co-application with fuod trap barriers would be optimal to maximize MD efficacy.

• Journal of the Korean Chemical Society
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• v.48 no.4
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• pp.371-378
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• 2004

The $SrGa_2S_4:Eu^{2+}$ green emitting phosphor has been studied as a luminous device for CRT (Cathode Ray Tube) or FED (Field Emission Display) and EL (Electroluminescence). This phosphor, also, is under noticed for LED (Lighting Emitting Diode) phosphor, which makes use of excitation characteristics of long wavelength region. The $SrGa_2S_4:Eu^{2+}$ phosphor was prepared generally conventional synthesis method using flux. However, this method needs high heat-treated temperature, long reaction time, complex process and harmful $H_2S$or $CS_2$ gas. In this works, therefore, we have synthesized $SrGa_2S_4:Eu^{2+}$ using SrS, $Ga_2S_3$, and EuS as starting materials, and the mixture gas of 5% H2/95% N2 was used to avoid the $H_2S$or $CS_2$. We investigated the luminescence characteristic of $SrGa_2S_4:Eu^{2+}$ phosphor prepared in various synthesis conditions, performed post-treatment and sieving process for application to LED.

• Korean Journal of Environmental Agriculture
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• v.36 no.3
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• pp.211-216
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• 2017

BACKGROUND:This study was conducted to investigate residual organochlorine pesticides (ROCPs) in agricultural soils and crops. Agricultural soil samples and crop samples were collected from 93 cities and counties. METHODS AND RESULTS: Extraction and clean-up for the quantitative analysis of ROCPs were conducted by the modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) method. Recovery and limit of detection (LOD) of ROCPs in agriculturalsoils and crops were 76.5-103.0 and 75.2-93.2%, 0.01-0.08 and $0.10-0.15{\mu}g/kg$, respectively. Detected ROCPs in agricultural soils were ${\alpha}$-endosulfan, ${\beta}$-endosulfan, and endosulfan sulfate, the residue were 2.0-12.0, 1.2-53.1, and $2.2-329.8{\mu}g/kg$, respectively. But these pesticides in all green perilla leaf and green pepper samples were not detected. CONCLUSION: These results showed that ROCPs residues in agricultural soils were not as high as crop safety threatening.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.17 no.2
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• pp.69-76
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• 2017

Citrin deficiency is an autosomal recessive disorder caused by mutations in the SLC25A13 gene on chromosome 7q21.3, and a type of urea cycle disorder that causes hyperammonemia. Although neonatal intrahepatic cholestasis and adult-onset type II citrullinemia, a type of citrin deficiency, have been described well in many articles for several decades, failure to thrive and dyslipidemia caused by citrin deficiency (FTTDCD), the other type of citrin deficiency, has been only identified recently. There was previously no case report about FTTDCD in Korea. Patients with FTTDCD could present with loss of appetite, fatigue, failure to thrive, hypoglycemia, hypercitrullinemia, dyslipidemia, and an increased lactate/pyruvate ratio. Routine evaluation may not reveal the cause of hypoglycemia caused by citrin deficiency. We recently had a case that presented with recurrent hypoglycemia in a 30-month-old boy. Chemistry profiling, urine organic acid analysis, plasma acylcarnitine analysis, and hormone studies indicated values within the normal range or non-specific findings. Mutation analysis to identify the cause of hypoglycemia identified the subject as a compound heterozygote carrying each of the c.852_855del ($p.Met285Profs^*2$), and c.1177+1G>A mutant alleles. We report here on this unusual case of citrin deficiency presenting with FTTDCD for the first time in Korea.