• Journal of Life Science
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• v.25 no.8
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• pp.870-879
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• 2015

The objective of this research was to evaluate the inhibitory activities of phenolic compounds isolated from mulberry (Morus alba) leaves of 109 types against α-amylase and α-glucosidase. The inhibitory activity of the water extracts from Morus alba cv. Kuksang against α-amylase and α-glucosidase were determined as 93.8% and 48.7% respectively. The total phenolic content of extracts from Morus alba cv. Kuksang was 9.7±0.2 mg/g soluble in water and 14.3±0.2 mg/g soluble in ethanol. The inhibitory activity of the water extracts from Morus alba cv. Kuksang at 200 μg/ml phenolics concentration against α-amylase and α-glucosidase were determined as 100% and 82.6% respectively. The purification of inhibitory compounds was carried out by Sephadex LH-20 and MCI-gel CHP-20 column chromatography using a gradient elution procedure by nomal phase type (EtOH→distilled water) and reverse phase type (distilled water→MeOH). The quercetin was confirmed to be the chemical structure of the inhibitory compound against α-amylase and α-glucosidase by spectroscopic analysis of FAB-MS, NMR and IR spectrum.

• Applied Biological Chemistry
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• v.22 no.3
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• pp.135-141
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• 1979

These experiments were conducted to investigate the conditions of the acid protease production by Rhizopus oryzae and the characteristics of crude enzyme. The results obtained were as follows: 1. The optimum culture time and the optimum amount of added water to the wheat bran medium were about 48 hrs and $80{\sim}120%$, respectively. 2. The addition of $(NH_4)_6Mo_7O_{24},\;(NH_4)_2SO_4,\;NH_4NO_3$, casein, and albumin, respectively, as nitrogen sources to the wheat bran medium was effective. Of these, the optimum concentrations of addition of $(NH_4)_6Mo_7O_{24}$ and casein which were the most effective were 0.1% and 1.0%, respectively. 3. The addition of glucose, galactose, maltose, lactose, and soluble starch, respectively, as carbon sources to the wheat bran medium was effective. Of these, the optimum concentration of addition of glucose which was the most effective was 3.0%. 4. The addition of $KH_2PO_4$ as a phosphate salt to the wheat bran medium was effective. The optimum concentration of addition of $KH_2PO_4$ was 0.3%. 5. The optimum pH for the enzyme action was 2.4, the optimum temperature about $40^{\circ}C$, and the stable pH range $2.0{\sim}5.0$. The enzyme was stab1e below $40^{\circ}C$. 6. The enzyme activity increased rapidly for 10 minutes after addition, thereafter it increased slowly. 7. The enzyme activity increased rapidly to 2 ml of addition, but nearly did not increase at the amounts greater than 2ml.

• Korean Journal of Materials Research
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• v.21 no.2
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• pp.111-114
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• 2011

As a growth-template of ZnO nanorods (NR), a hexagonal $\beta-Ni(OH)_2$ nanosheet (NS) was synthesized with the low temperature hydrothermal process and its microstructure was investigated using a high resolution scanning electron microscope and transmission electron microscope. Zinc nitrate hexahydrate was hydrolyzed by hexamethylenetetramine with the same mole ratio and various temperatures, growth times and total concentrations. The optimum hydrothermal processing condition for the best crystallinity of hexagonal $\beta-Ni(OH)_2$ NS was determined to be with 3.5 mM at $95^{\circ}C$ for 2 h. The prepared $Ni(OH)_2$ NSs were two dimensionally arrayed on a substrate using an air-water interface tapping method, and the quality of the array was evaluated using an X-ray diffractometer. Because of the similarity of the lattice parameter of the (0001) plane between ZnO (wurzite a = 0.325 nm, c = 0.521 nm) and hexagonal $\beta-Ni(OH)_2$ (brucite a = 0.313 nm, c = 0.461 nm) on the synthesized hexagonal $\beta-Ni(OH)_2$ NS, ZnO NRs were successfully grown without seeds. At 35 mM of divalent Zn ion, the entire hexagonal $\beta-Ni(OH)_2$ NSs were covered with ZnO NRs, and this result implies the possibility that ZnO NR can be grown epitaxially on hexagonal $\beta-Ni(OH)_2$ NS by a soluble process. After the thermal annealing process, $\beta-Ni(OH)_2$ changed into NiO, which has the property of a p-type semiconductor, and then ZnO and NiO formed a p-n junction for a large area light emitting diode.

• Journal of the Korean Wood Science and Technology
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• v.45 no.3
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• pp.250-257
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• 2017

Eight hydrolyzable tannin compounds, such as gallic acid (1), methyl gallate (2), kurigalin (3), 1,2,3,6-tetra-O-galloyl-${\beta}$-D-(+)-glucose (4), 1,2,3,4,6-penta-O-galloyl-${\beta}$-D-(+)-glucose (5), 6-m-digalloyl-1,2,3,4,6-penta-O-galloyl-${\beta}$-D-(+)-glucose (6), isocorilagin (7), macabarterin (8), were isolated from the EtOAc and $H_2O$ soluble fractions of Katsura tree (Cercidiphyllum japonicum) leaves, wood and bark. Then antioxidative and anti-inflammatory activity were evaluated on the each isolated compound. The antioxidative test was DPPH radical scavenging activity and all of the isolated compounds indicated much higher antioxidative values compare to the controls, BHT and ${\alpha}$-tocopherol. In the anti-inflammatory test measuring nitric oxide (NO) inhibition activity, methyl gallate, 1,2,3,6-tetra-O-galloyl-${\beta}$-D-glucose and 1,2,3,4,6-penta-O-galloyl-${\beta}$-D-glucose inhibited NO production, and especially, methyl gallate showed high inhibition activity. However, the anti-inflammatory activity of the hydrolyzable tannins did not show positive effect. Based on the above results, the hydrolyzable tannins of katsura tree may be used as one of the natural biomass sources that can substitute with the synthetic antioxidant.

• Journal of Microbiology and Biotechnology
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• v.30 no.8
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• pp.1156-1168
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• 2020

Drought stress is threatening the growth and productivity of many economical crops. Therefore, it is necessary to establish innovative and efficient approaches for improving crop growth and productivity. Here we investigated the potentials of the cell-free extract of Actinobacteria (Ac) isolated from a semi-arid habitat (Al-Jouf region, Saudi Arabia) to recover the reduction in maize growth and improve the physiological stress tolerance induced by drought. Three Ac isolates were screened for production of secondary metabolites, antioxidant and antimicrobial activities. The isolate Ac3 revealed the highest levels of flavonoids, antioxidant and antimicrobial activities in addition to having abilities to produce siderophores and phytohormones. Based on seed germination experiment, the selected bioactive fraction of Ac3 cell-free extract (F2.7, containing mainly isoquercetin), increased the growth and photosynthesis rate under drought stress. Moreover, F2.7 application significantly alleviated drought stress-induced increases in H₂O₂, lipid peroxidation (MDA) and protein oxidation (protein carbonyls). It also increased total antioxidant power and molecular antioxidant levels (total ascorbate, glutathione and tocopherols). F2.7 improved the primary metabolism of stressed maize plants; for example, it increased in several individuals of soluble carbohydrates, organic acids, amino acids, and fatty acids. Interestingly, to reduce stress impact, F2.7 accumulated some compatible solutes including total soluble sugars, sucrose and proline. Hence, this comprehensive assessment recommends the potentials of actinobacterial cell-free extract as an alternative ecofriendly approach to improve crop growth and quality under water deficit conditions.

• Applied Biological Chemistry
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• v.22 no.4
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• pp.210-216
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• 1979

RNA degrading bacteria were isolated from soil of Korea. One strain (no. JSC-114), having strong 5'-phosphodiesterase activity, was identified as belonging to the genus Streptomyces on the basis of taxonomic characteristics. The optimum conditions of 5'-phophosdiesterase production were found at $30^{\circ}C$ for 4 day in a medium containing 4.5% of soluble starch, 0.15% of peptone, 0.6% of yeast extract, 0.1% of $MgSO_4{\cdot}7H_2O$, 0.01% of $CaCl_2{\cdot}2H_2O$, 0.25% of $KNO_3$, and 0.5% of $KH_2PO_4$(pH 7.0). The maximum production rate of 5'-nucleotides from yeast RNA was 95% at $40-45^{\circ}C$ for 4hrs, and the products were identified as 5'-IMP, 5'-GMP, 5'-CMP and 5'-UMP(5.5 : 5.0 : 4.9 : 5.0).

• The Korean Journal of Nuclear Medicine
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• v.22 no.1
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• pp.65-76
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• 1988

High affinity complexes for the tumor were obtained by changing pH and composition in the preparation of $^{99m}Tc-DMSA$. The purpose of this study was to investigate the tumor affinity, and in vitro and in vivo characteristics of these complexes. The results obtained were as follows; 1) Tumor imaging agent was formed successfully at pH $6.0\sim9.0$ and renal imaging agent at pH $2.0\sim5.0$. 2) The serum protein binding of $^{99m}Tc-DMSA$ was $89.1\sim92.8%$ at pH $2.0\sim5.0$ and $11.8\sim30.5%$ at pH $6.0\sim9.0$ respectively, and it was not changed with time. 3) The T 1/2 of tumor affinity complex in blood between 3 and 6 hours after injection was $187{\pm}29$ minutes $(mean{\pm}SD)$. 4) In the blood, the radioactivity was mainly in the plasma, and less than 1% was in the cellular components. 5) In the Walker carcinosarcoma 256 bearing Wistar rats, the radioactivity in the kidney increased, and decreased in the skeleton with time. The radioactivity in the tumor showed the peak in 6 hours after injection and decreased thereafter. 6) In the tumor cell, the radioactivity localized mainly in the cytosol, the soluble fraction of the cytoplasm. This study provides the basic knowledge about tumor affinity and usefulness of $^{99m}Tc-DMSA$ in the diagnosis of malignant disease.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.2
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• pp.85-92
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• 2011

Evaluation of the removal efficiencies of Fe(II) by reactive sand media coated with manganese (MCS), iron (ICS) and both of iron and manganese (IMCS) was investigated as functions of solution pH ranging from 2 to 9, reaction time and concentration of Fe(II) in a batch reactor using each reactive medium and additional oxidants such as $KMnO_4$ and NaOCl. When only Fe(II) was present in solution without any reactive medium, removal of Fe(II) was quite low below pH 5 due to a slow oxidation of Fe(II) and/or negligible precipitation but greatly increased above pH 5 due to a rapid oxidation of Fe(II) and subsequent precipitation of oxidized Fe species. ICS showed negligible efficiency on the removal of Fe(II) through adsorption. However, an efficient removal of Fe(II) was observed at low solution pH in the presence of IMCS or MCS through rapid oxidation and subsequent precipitation. Removal efficiency of Fe(II) by IMCS in the presence or absence of NaOCl was quite similar. Removal rate of Fe(II) by IMCS and additional oxidants gradually increased as the solution pH increased. From the kinetic experiments, removal pattern of Fe(II) was better described by pseudo-second-order equation than pseudo-first-order equation. A rapid removal of Fe(II) using IMCS in the presence of $KMnO_4$ was observed in the first 10 min. The initial removal rate of Fe(II) using $KMnO_4$ was 14,286 mg/kg hr. In case of using NaOCl, the removal of Fe(II) occurred rapidly in the first 6 hrs and then reached the near-equilibrium state. Removal of Fe(II) on IMCS was well expressed by Langmuir isotherm and the maximum removal capacity of Fe(II) was calculated as 1,088 mg/kg.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2004.05a
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• pp.298-300
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• 2004

본 연구에서는 생리 활성 효과가 기대되며, 기능적으로 활성도가 높은 복분자즙을 실용적으로 활용하는 방안으로 복분자즙의 치즈 원유 첨가비를 달리한 (2%, 4%, 6%) 아펜젤러 치즈를 제조 하였다. 각 처리구별 치즈를 4개월간 숙성하면서 숙성중 치즈의 생균수.pH NPN(non protein nitrogen) , NCN(non casein nitrogen) , WSN (water soluble nitrogen)의 함량 변화를 조사하였다. 치즈 첨가함량별 치즈제조 및 숙성 결과 4%구에서 높은 숙성도를 보였고 관능검사에서도 6%구에서 높은 기호도를 나타내 추가적인 연구가 수행된다면 이상적인 한국적 기능성 자연 치즈 개발이 가능할 것으로 기대 되었다.

• Journal of the Korean Ceramic Society
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• v.30 no.11
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• pp.967-973
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• 1993

The effect on the hydration of cement was that Cu and Pb reacted with alkali to form soluble hydrates at theinitial stage and then there followed a slow reaction forming insoluble metal hydroxides. These hydroxides were deposited on the surface of cement particles providing a barrier against further hydration. But as a slow reaction continued, the insoluble layers were eventually destroyed and the hydration reaction resumed. Thereafter, another retardation occured by restricting the polymerization of silicates, shown by FT-IR spectroscopy analysis. In the case of Cr, as its reaction with cement caused H2O, the coordinator of Cr complex, to replace or polymerize with OH-, the formation of Cr complex promoted the leakage of OH- and increased the heat of dissolution. So the total heat evolution during hydration was larger than that in the case of Pb or Cu. The retarding effect of heavy metal ions was in the order Pb>Cu>Cr.