• Journal of the Korean Chemical Society
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• v.40 no.7
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• pp.474-482
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• 1996

Two crystal structures of the vacuum dehydrated $Ag^+$-exchanged zeolite X have been determined by single-crystal X-ray diffraction techniques in the cubic space group Fd3 at 21(1)$^{\circ}C$ (a=24.922(1)${\AA}$ and a=24.901(1)${\AA}$, respectively). Each crystal was ion exchanged in flowing streams of aqueous $AgNO_3$ for three days. The first crystal was dehydrated at 300$^{\circ}C$ and $2{\times}10^{-6$torr for two days. The second crystal was similarly dehydrated at 350$^{\circ}C$. Their structures were refined to the final error indices, $R_1=0.095\;and\;R_2=0.092$ with 227 reflections, and $R_1=0.096\;and\;R_2=0.087$ with 334 reflections, respectively, for which I > 3${\sigma}$(I). In the first crystal, Ag species are found at five different crystallographic sites: sixteen $Ag^+$ ions fill the site I, the center of the double 6-ring, thirty-two Ag0 atoms fill the I' site in the sodalite cavities opposite double six-rings, seventeen $Ag^+$ ions lie at the 32-fold site II' inside the sodalite cavity at the single six-oxygen ring in the supercage, fifteen Ag+ ions lie at the 32-fold site II, in the supercage, and the remaining twelve $Ag^+$ ions lie at site III' in the supercage at a little off two-fold axes. In the second crystal, all Ag species are located similarly as crystal 1; 16 at site I, 28 at site I', 16 at site II, 16 at site II', 6 at site III and 6 at site III'. Total 88 silver species were found per unit cell. The remaining four Ag atoms were migrated out of the zeolite framework to form small silver crystallites on the surface of the zeolite single crystal. In the first structure, the numbers of Ag atoms per unit cell are approximately 32.0 and these may form tetrahedral $Ag_4$ clusters at the centers of the sodalite cavities. The probable four-atom cluster is stabilized by coordination to two $Ag^+$ ions. The Ag-Ag distance in the cluster, ca. 3.05 ${\AA}$, is a little longer than 2.89 ${\AA}$, Ag-Ag distance in silver metal. At least two six-ring $Ag^+$ ions on sodalite cavity (site II') must necessarily approach this cluster and this cluster may be viewed as a distorted octahedral silver cluster, (Ag6)2+.

• Journal of the Korean Society of Food Science and Nutrition
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• v.3 no.1
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• pp.17-21
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• 1974

Tasty constituents such as free amino acids. free organic acids and free sugars and minerals in clavariaceae botrytis were surveyed through the course of this study. The results were as, follows: 1. Isoleucine valine threonine alanine methionine cysteine glutamine histidine glutamic acid and aspartic acid were presented in clavariaceae botrytis, and aspartic acid showed the highest amount. 2. Succinic acid was the major organic acid in clavariaceae botrytis, and also citric acid malic acid and fumaric acid were presented. 3. Clavariaceae botrytis contained fructose, maltose glucose and sucrose ; glucose and sucrose were more than 80% of total sugars. 4. Na K Mg Ca Zn Mn Cu am Fe by atomic absorption spectrometer were detected and assayed. and Al Si Ni Sn Ti Cr Ag Pb B and Sr detected by emission spectrograph. K of these minerals showed the highest amount but very small amount of Ca was presented.

• Korean Journal of Food Science and Technology
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• v.46 no.5
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• pp.575-580
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• 2014

Model gel food samples of yanggaeng (Y) were prepared for the elderly with various gelling agents, including agar (AG), low acyl gellan (GL), ${\kappa}$-carrageenan (CA), locust bean gum (LB), glucomannan (GM), and xanthan gum (XA) in different combinations as follows (in 1:1 ratio): LB+CA, GM+XA, and GM+CA. The quality characteristics of the different combinations were compared. The results revealed that water loss was highest for Y-GL, whereas there was no significant difference among the other samples. Y-GL showed the highest values for lightness in color, whereas Y-AG showed the lowest. Regarding textural properties, Y-LB+CA had the highest hardness value, whereas Y-GL had the lowest; the hardness of Y was related to the cross-section of the added gel. Finally, Y-GM+XA exhibited the highest score in overall acceptability in the sensory test by elderly, indicating that the preferable texture by elderly is slightly chewy, but not adhesive.

• KSBB Journal
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• v.17 no.1
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• pp.20-25
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• 2002

We performed a basic experiment for rapid, on-line, real-time measurement of HBsAg by using a surface plasmon resonance biosensor to quantify the recognition and interaction of biomolecules. We immobilized the anti-HBsAg polyclonal antibody to the dextran layer on a CM5 chip surface which was pre-activated by N-hydroxysuccinimide for amine coupling. The binding of the HBsAg to the immobilized antibody was measured by the mass increase detected by the change in the SPR signal. The binding characteristics between HBsAg and its antibody followed typical monolayer adsorption isotherm. When the entire immobilized antibody was interacted, there was no additional, non-specific binding observed, which suggested the biointeraction was very specific as expected and independent of the ligand density. No significant steric hindrance was observed at 17.6 nm/$mm^2$ immobilization density. The relationship between the HBsAg concentration in the sample solution and the antigen bound to the chip surface was linear up to ca. $40\mu\textrm{g}$/mL, which is much wider than that of the ELISA method. It appeared the antigen-antibody binding was increased as the immobilized ligand density increased, but verification is warranted. This study showed the potential of this biosensor-based method as a rapid, simple, multi-sample, on-line assay. Once properly validated, it can serve as a more powerful method for HBsAg quantification replacing the current ELISA method.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.4
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• pp.218-227
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• 2015

A prerequisite for precise quantification of nanomaterials contained in environmental samples is to prepare suitable preservation conditions of samples. This study was initiated to suggest preservation conditions of aqueous samples for analyses of metal nanomaterials. Variation in the size of silver nanomaterial (cit-AgNP) was observed according to change in various conditions, such as pH, electrolyte concentration, temperature, nanomaterial concentration, and time. Aggregation of AgNP was characterized for each environmental condition, and finally proper preservation conditions of samples were proposed based on experimental results on AgNP aggregation. In addition, the preservation period of sample was computed by the doublet time of AgNP. The results indicate that the aggregation rate of cit-AgNP was close to 0 at the conditions of pH of ${\geq}7$, electrolyte ($Ca(NO_3)_2$) concentration of ${\leq}3mM$, temperature of $4^{\circ}C$, and cit-AgNP concentration of ${\leq}2mg/L$. Furthermore, the experimental results on doublet time of cit-AgNP suggest that maximum preservation period was evaluated to be 15.79~17.53 days when the concentration of 100 nm cit-AgNP is assumed to be $1{\mu}g/L$ which is considered as an environmentally-relevant concentration of engineered nanomaterials. Our results suggest that samples should be preserved at $4^{\circ}C$ and analyzed within 2 weeks.

• Korean Journal of Materials Research
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• v.7 no.2
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• pp.140-144
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• 1997

The effects of the particle size of precursor powder on the microstructure and Jc of Ag-sheathed Ri-2223 tapes were investigated. The calcined powder with overall composition of $Bi_{1-89}Pb_{0-41}Sr_{2-01}Ca_{2-23}Cu_{3-03}O_{y}$ was milled for various times using planetary ball mill. The transport property of the tapes were found to depend strongly on the particle size of the precursor powder Enhanced reactivity of the milled powder facilitated the formation of 2223 phase and resulted in an increase of Jc. Excessive milling, however, led to the amorphisation of the powder and degraded the electrical property of the tapes.

• Korean Journal Plant Pathology
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• v.14 no.3
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• pp.260-267
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• 1998

This study was undertaken to find a new formulation of soil amendment, and selection of antogonists and to effectively control brown and large patch of turfgrasses caused by Rhizoctoniz solani AG1-1 and AG 2-2. Fourteen inorgainc chemicals (1%, w/w) were added individually in vitro, and some chemicals showed suppressiveness to R. solani. Alum suppressed effectively mycelial growth of R. solani in the range of 17 to 77% as compared with control. The four chemicals such as Al2(SO4)3, alum, CaO, and NH4NO3 were finally selected. Out of three organic compounds, composted pine bark (CPB) showed prominent suppressive effect as compared with milled alfalfa and pine leaves. After inoculation of R. solani isolates AG-1 and AG2-2 on the turf seedlings, water soaked lesions and blight symptoms were developed on the whole seedlings. According to inhibition zone method, mycelial growth of the fungus were greatly suppressed by culture filterates of the antagonists, Gliocladium virens (Gl1-) and Pseudomonas sp. (P713). CPB soil amendment mixed with antagonists (1% w/w) controlled not only brown and large patch of turfgrasses, but also promote the good growth of the seedlings. In addition, the controlling effect was maintained more than 30 days. Especially, the controlling effect of two antagonists was similar to Cㅖㅠ soil amendment with the antagonists and also stimulated a favorable growth of the seedlings. Therefore, its is expected that continuous control of Rhizoctonia blight of turfgrasses can be obtained in field by subsequent applications of the antagonists.

• Proceedings of the Korean Magnestics Society Conference
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• 2008.12a
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• pp.47.2-47.2
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• 2008

• Korean Journal of Veterinary Research
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• v.43 no.3
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• pp.361-371
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• 2003

The vasorelaxant actions and blood pressure lowering of the ${\alpha}_2$-adrenoceptor agonists (${\alpha}_2$-AAs) clonidine and xylazine were investigated in rat isolated aortic rings and anesthesized rats. Both clonidine and xylazine produced a concentration-dependent inhibition of the sustained contraction induced by norepinephrine (NE), but not by KCl. NE-induced contractions were attenuated partly by nifedipine or verapamil, voltage dependent $Ca^{2+}$ channel blockers. These $Ca^{2+}$ channel blockers-resistant contractions were abolished by clonidine or xylazine. Inhibitory effects of a ${\alpha}_2$-AAs on contractions could be reversed by ryanodine, an intracellular $Ca^{2+}$, transport blocker, and tetrabutylammonium (TBA), a $Ca^{2+}$ activated $K^+$ channel blocker, but not by nifedipine, glibenclamide or removal of extracellular $Ca^{2+}$ and endothelium. Moreover, ${\alpha}_2$-AAs produced relaxation in NE-precontracted isolated intact aortic rings in a concentration-dependent manner, but not in KCl-precontracted rings. The relaxant effects of ${\alpha}_2$-AAs were inhibited by ryanodine and TBA, but not by nifedipine, glibenclamide, N (G)-nitro-L-arginine (L-NNA), N(omega)-nitro-L-arginine methyl ester (L-NAME), aminoguanidine (AG), 2-nitro-4-carboxyphenyl N,N-diphenylcarhurnte (NCDC), lithium sulfate, staurosporine or removal of extracellular $Ca^{2+}$ and endothelium. In vivo, infusion of xylazine elicited significant decrease in anerial blood pressure. This xylazinelowered blood pressure was completely inhibited by the intravenous injection of TBA, but not by the intravenous injection of glibenclamide, L-NNA, L-NAME, AG, nifedipine, lithium sulfate or saponin.. These findings showed that the receptor-mediated and ${\alpha}_2$-adrenoceptor A-stimulated endothelium-independent vasorelaxant effect may be explained by decreasing intracellular $Ca^{2+}$ release and activation of $Ca^{2+}$-activated $K^+$ channels, which may contribute to the hypotensive effects of ${\alpha}_2$-AAs in rats.

• Korean Journal of Food Science and Technology
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• v.12 no.1
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• pp.1-5
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• 1980

Crude invertase was obtained from the water extracts of Korean ginseng, Panax ginseng C. A. Meyer, by fractionation with $0.8{\sim}1.0$ saturation of ammonium sulfate. The properties of the crude invertase were as follows: Crude invertase was stable in the pH range between 5 and 9, and at the temperature below $35^{\circ}C$. Crude invertase showed the optimum pH at 5.0 and the optimum temperature at $50^{\circ}C$. The activity of the crude invertase was inhibited by $Ag^{+}\;Mn^{+}\;Hg^{+}\;Zn^{+},\;and\;Rb^{+}$, while $Ca^{+}\;Cu^{+},\;and\;Fe^{3+}$ demonstrated remarkable increasing effects on the enzyme activity.