• Biomedical Science Letters
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• v.6 no.3
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• pp.209-221
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• 2000

The purpose of this study was to investigate the practical availability of pretense production that can be used at home after isolating Serratia sp.2000-1 which produced extracellular pretense from clinical specimen. Basic production conditions and partial enzymatic characteristics of pretense produced by Serratia sp. 2000-1 was as follows: The kind and concentration of carbohydrate, nitrogen and metal salts for optimal enzyme production condition were each identified as the concentration of 1.5% glucose, 2.0% CSP, and 0.1% CaCl$_2$, and the optimal temperature, time and initial pH for culture were each 3$0^{\circ}C$, 72 hours, and pH 8.0. The final enzymatic yeild that was purified by 3 steps with ammonium sulfate precipitation (45~80%), DEAE-cellulose column chromatography, and Sephadex G-200 gel chromatography was 14.4%, and enzyme inactivity rate increased approximately 291314s. The optimal temperature and pH for purified pretense activity were 35$^{\circ}C$ and pH 7.0~8.0, and purified pretense activity was relatively stable by 4$0^{\circ}C$ at pH 6~10 for 30 min, however heating at 6$0^{\circ}C$ for 30 min, it liminated detectable pretense activity. The pretense activity was activated by $Mg^{2+}$, $Ba^{2+}$, $Ca^{2+}$, Mn$^{2+}$, but inactiviaed by Hg$^{2+}$, Ag$^{2+}$, Cu$^{2+}$, and the pretense activity was inhibited strongly by SDS among enzyme activity inhibitors. Further study is required to evaluate the practical availability of pretense production that can be used at home by isolating Serratia sp. from more clinical specimen and examining pretense more in details.

• Microbiology and Biotechnology Letters
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• v.17 no.5
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• pp.481-488
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• 1989

A serum-free medium that could be used for the large-scale culture of mouse hybridoma to produce monoclonal antibodies was developed. The medium was based on a 1:1 mixture of Iscove's Modified Dulbecco's Medium and Ham's F-12, supplemented with insulin 10$\mu\textrm{g}$/$m\ell$, transferrin 10$\mu\textrm{g}$/$m\ell$, ethanolamine 10$\mu$M and selenium 30nM (designated EBM (enriched basal medium) with the supplements). The effect of various supplements of steroid hormones, vitamins, lipid and mineral salts was investigated and their optimal concentration was determined to replace fetal calf serum (PCS). These components were added respectively and then added by way of two or three combination to discern of which component combination was effective to the culture of hybridoma. As a result, serum-free medium KM3 (EBM with BSA 100$\mu\textrm{g}$/$m\ell$, mineral cocktail and 0.05% PEG) was deter-mined. The hybridoma Alps 25-3 cultured in this medium showed almost the same growth rate as in medium added with 2% fetal bovine serum. However, the antibody concentration from KM3 cultures was 80% of that obtained from culture with FCS. KM3 was also examined for the culture of other mouse hybridomas, KW, A4W & HCGK, and it was confirmed that it could support the growth of these hybridomas and the production of monoclonal antibodies.

• Journal of the Korea Concrete Institute
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• v.15 no.6
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• pp.829-839
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• 2003

Recently, the corrosion of reinforced concrete structures has received great attention related with the deterioration of sea-side structures, such as new airport, bridges, and nuclear power plants. In this regards, many studies have been done on the chloride attack in concrete structures. However, those studies were confined mostly to the single deterioration due to chloride only, although actual environment is rather of combined type. The purpose of the present study is, therefore, to explore the influences of carbonation to chloride attack in concrete structures. The test results indicate that the chloride penetration is more pronounced than the case of single chloride attack when the carbonation process is combined with the chloride attack. It is supposed that the chloride ion concentration of carbonation region is higher than the sound region because of the separation of fixed salts. Though the use of fly ash pronounces the chloride ion concentration in surface, amounts of chloride ion penetration into deep region decreases with the use of fly ash. The present study allows more realistic assessment of durability for such concrete structures which are subjected to combined attacks of both chlorides and carbonation but the future studies for combined environment will assure the precise assessment.

• Korean Journal of Plant Resources
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• v.27 no.5
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• pp.540-545
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• 2014

The Polygonatum odoratum cv. Gungangbeaksea, bred in Gyeongsangnam-Do Agricutural Research & Extension Service, was cultured in vitro for micropropagate rapidly through the culture of rhizome explants ($5{\times}5mm$). The $7{\times}7mm$ explants of adventitious multi-bud clusters (AMC), obtained through the culture of rhizome explants (MS + 3.0 mg/L BA) were cultured on MS media with BA and TDZ. The shoot multiplication was favorable on the MS medium containing 3.0 mg/L TDZ with 2.8 in shoot number. But the formation of AMC was low in all media tested. The explants of AMC were cultured on MS media containing 1.0~5.0 mg/L TDZ and NAA to multiplicate AMC more. The formation of AMC was a little more stimulated on combined MS media of TDZ and NAA, than that with TDZ alone. The multiplication of shoots and AMC was favorable on MS media with 3.0 mg/L TDZ and 5.0 mg/L NAA, and 5.0 mg/L TDZ and 3.0 mg/L NAA. As the concentration of MS salts increased, the formation of AMC was decreased. But the formation of AMC was more stimulated, as the concentration of sucrose increased to 7%. Therefore, the multiplication of shoots and AMC was suitable on media containing 3.0~5.0 mg/L TDZ and NAA, and 7% of sucrose. The explants of AMC were rooted on media with 3.0 mg/L IBA, or 2.0 mg/L NAA with more than 80% in rooting ratio. The plantlets were treated at $5^{\circ}C$ for 8 weeks, and cultured ex vitro for 8 weeks. The survival ratio of plantlets were 100% in vermiculite, and the mixed soil with perlite 1 volumn and vermiculite 1 volumn.

• Applied Chemistry for Engineering
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• v.28 no.6
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• pp.670-678
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• 2017

Self-emulsifiable polyethylene (PE) wax was prepared using acrylic acid grafted PE wax with potassium hydroxide and various emulsifiers for the economic production of PE wax emulsion. Modification reaction completion was confirmed that the peak from carbonyl group of acrylic acid disappeared and the new peak from carboxylic acid salts appeared in the FT-IR (Fourier transform infrared) spectrum data. Self-emulsifiable properties of the modified PE wax were investigated by the emulsion size and the stability of wax emulsion without any additional emulsifiers. According to self-emulsifiable properties, the emulsion size and stability were varied on the concentration and structure of the emulsifier. The greater emulsion concentration and hydrophilic poly(ethylene oxide) (PEO) characteristics of the emulsifier resulted in the smaller emulsion size and better emulsion stability. In addition, the use of emulsifiers mixture was more effective to obtain smaller size and uniform distribution of emulsion than that of single emulsifier in PE wax modification reaction. Especially, modified PE wax with OAE-5 and LAE-15 emulsifiers mixture shows excellent performance in terms of the smallest emulsion size ($4.34{\mu}m$) and emulsion stability.

• Korean Journal of Environmental Agriculture
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• v.27 no.4
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• pp.349-355
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• 2008

The causes of salt accumulation in soils of plastic film houses nearby Sumjin river estuary in Mokdo-ri($127^{\circ}46'E\;35^{\circ}1'N$), Hadong, Gyeongnam, Korea were investigated in 2006. With chemical properties soils and water analyzed and fertilization status monitored, the study showed that mean salt concentration of soil was much higher at EC $4.3\;dS\;m^{-1}$ than the Korean average (EC $2.9\;dS\;m^{-1}$) in 2000s for plastic film house's soil with exchangeable Na $0.8\;cmol^+\;kg^{-1}$ and water-soluble Cl $232\;mg\;kg^{-1}$, and then might result to salt damage in sensitive crop plants. Salt concentration of ground water used as main irrigation water source contained very high EC with corresponding value of $2.6\;dS\;m^{-1}$. Particularly, increase of EC value was directly proportional with the increased pumping of ground water used as a water-covering system in order to protect the temperature inside plastic film houses from the early winter season. High Na and Cl portion of ions in water might had contributed to the specific ion damage in the crops. Secondly, heavy inputs of chemicals and composts significantly increased the accumulated salts in soil. Conclusively, salt accumulation might had been accelerated by use of salted-groundwater irrigation and heavy fertilization rate. To minimize this problem, ensuring good quality of irrigation water is essential as well as reducing fertilization level.

• Polymer(Korea)
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• v.35 no.5
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• pp.438-443
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• 2011

In order to enhance water permeability through the improvement of fouling phenomena and wettability of hydrophobic porous membranes, various adsorption materials, i.e., poly(vinyl amine), poly (styrene sulfonic acid), poly(vinyl sulfonic acid), and poly(acrylamide-co-acrylic acid) were adsorbed onto the surface of polyethylene (PE) porous membrane. The concentration of adsorption solutions, adsorption time, the sort of salts and their ionic strength were varied, and the pure water permeability of their resulting adsorbed membranes was measured. In general, water permeability increased with an initial increase in the concentration of adsorption solution, adsorption time, and ionic strength and then decreased with a further increase. The pure water permeability of 375 $L/m^2h$(LMH), 35% enhancement, was obtained at a condition of poly(vinyl sulfonic acid) 1000 ppm, $Mg(NO_3)_2$ ionic strength(IS) 0.1, and adsorption time 150 sec, while the 50% (411 LMH) and 35% (374 LMH) enhancements were obtained at conditions of poly(styrene sulfonic acid) 1000 ppm, adsorption time 60 sec, and NaCl IS 0.1 and 0.2, respectively.

• Bulletin of the Korean Chemical Society
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• v.31 no.6
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• pp.1519-1526
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• 2010

The behavior of peptide or protein solutes in saline aqueous solution is a fundamental topic in physical chemistry. Addition of ions can strongly alter the thermodynamic and physical properties of peptide molecules in solution. In order to study the effects of added ionic salts on protein conformation and dynamics, we have used the molecular dynamics (MD) simulations to investigate the behavior of Staphylococcus aureus Hfq protein under two different ionic concentrations: 0.1 M NaCl and 1.0 M NaCl in presence and absence of RNA (a hepta-oligoribonucleotide AU5G). Hfq, a global regulator of gene expression is highly conserved and abundant RNA-binding protein. It is already reported that in vivo the increase of ionic strength results in a drastic reduction of Hfq affinity for $Q{\beta}$ RNA and reduces the tendency of aggregation of Escherichia coli host factor hexamers. Our results revealed the crucial role of 0.1 M NaCl Hfq system on the bases with strong hydrogen bonding interactions and by stabilizing the aromatic stacking of Tyr42 residue of the adjacent subunits/monomers with the adenine and uridine nucleobases. An increase in RNA pore diameter and weakened compactness of the Hfq-RNA complex was clearly observed in 1.0 M NaCl Hfq system with bound RNA. Aggregation of monomers in Hfq and the interaction of Hfq with RNA are greatly affected due to the presence of high ionic strength. Higher the ionic concentration, weaker is the aggregation and interaction. Our results were compatible with the experimental data and this is the first theoretical report for the experimental study done in 1980 by Uhlenbeck group for the present system.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.3
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• pp.373-378
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• 2008

The objective of this paper was to investigate optimal culture conditions for the production of an inhibitor against subtilisin-like protease from Streptomyces thermocarboxydus (S. thermocarboxydus) C12 isolated from sediments of Gwangyang coast. The optimal temperature and initial pH for the production of subtilisin-like protease inhibitor were $40^{\circ}C$ and pH 8.0, respectively. Inhibition activities were high for galactose, glucose and fructose. The best carbon source and its concentration were galactose and 1.6% (w/v), respectively. Inhibition activities were also high in medium containing polypeptone, proteose and peptone. Optimal nitrogen source and concentration were protease peptone and 0.5% (w/v), respectively. Optimal concentrations for inhibitor production were 1% (w/v) for NaCl and 1 mM LiCl for metal salts. The subtilisin-like protease inhibitor from S. thermocarboxydus C12 showed a maximum inhibitor activity after cultivation for 84 h under the optimized medium.

• Clean Technology
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• v.20 no.4
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• pp.349-353
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• 2014

Succinic acid is an important precursor in industries producing biopolymers, pharmaceutical and food additives and green solvents. However, due to the high price of petroleum and the global $CO_2$ emission, the biological production of succinic acid from renewable biomass is a novel process due to the fixation of $CO_2$ into succinate during fermentation. In this study, aqueous two phase systems based on imidazolium ionic liquids/$K_2HPO_4$ were used as an effective separation and concentration process for succinic acid. Experimental results show that aqueous two phase systems can be formed by adding appropriate amount of imidazolium ionic liquids to aqueous $K_2HPO_4$ solutions in the presence of succinic acid. It can be found that the ability of imidazolium ionic liquids for phase separation followed the order [HMIm][Br]${\fallingdotseq}$[OMIm][Br]>[BMIm][Br]>[EMIm][Br]. The maximum value of extraction efficiency for succinic acid was about 90% and the amount of coextracted water into top phase is proportional to the chain length of cation in imidazolium ionic liquids. It was concluded that the aqueous two phase systems composed of imidazolium ionic liquids/$K_2HPO_4$ was effective for the selective extraction and concentration of succinic acid.