• KSBB Journal
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• v.21 no.3
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• pp.181-187
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• 2006

In this study, problems related with pH control in electrokinetic(EK) bioremediation of phenanthrene contaminated soil were observed, and the effects of pH control methods on the removal efficiency were investigated to search a further application strategy. In a preliminary experiment, it was found out by flask cultivation that a certain sulfate concentration was needed to degrade phenanthrene well using Sphingomonas sp. 3Y. However, when $MgSO_4$ was used as sulfate source in EK bioremediation, the bacterial activity reduced seriously due to the abrupt decrease of pHs in soil and bioreactor by the combination of magnesium and hydroxyl ions. When another strong buffering compound was used to control the pH problem, the good maintenance of the bacterial activity and pHs could be observed, but the removal efficiency decreased largely. When a low concentration of $MgSO_4$ was added, the removal efficiency decreased somewhat in spite of the good maintenance of neutral pHs. With the addition of NaOH as a neutralizing agent, the removal efficiency also decreased because of the increase of soil pH. Consequently the selection of electrolyte composition was a very important factor in EK bioremediation and some sulfate sources suitable for both bacterial activity and contaminant degradation should be investigated.

• Journal of the Korean Institute of Gas
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• v.11 no.3
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• pp.7-12
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• 2007

The search for a new fire-extinguishing agent with all the desirable properties of halon 1301 has not been successful. To study binary gaseous extinguishing agents instead, one has to determine the extinguishing concentrations for several compositions of a given chemical in an inert gas. This process is expensive and time consuming. The fire suppression efficiencies of gas mixtures of HFC 125 and HFC 227ea with nitrogen as total flooding agents were studied by cup burner method. It was shown that addition of small amounts of those extinguishants to nitrogen can enhance the suppression effectiveness of the inert gas. As expected, the degree of synergism was highest at low concentrations of the chemical. For each binary system, extinguishing concentrations of the pure compounds and one binary data were used to predict the extinguishing concentrations for the entire range of binary composition. The predicted values were very close to experimental data.

• The Korean Journal of Pharmacology
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• v.22 no.2
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• pp.105-114
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• 1986

This study was undertaken to search for a new antiarrhythmic agent in natural plants. Extracts of Buxus microphylla var. koreana Nakai have been used as folk remedies of several diseases, including malaria and venereal disease, but any study on the pharmacological actions of this plant has not yet been carried out and its active ingredients have not been identified. In our laboratory, we isolated buxuletin (nonalkaloid) and cyclobuxine D (steroidal alkaloid) from Buxus microphylla var. koreana Nakai and reported their pharmacological actions: diuretic effects of buxuletin in rabbits and hypotensive effect of cyclobuxine D in rats. In the present study, we investigated the effect of cyclobuxine D on isolated frog heart and heart rate in urethane anesthetized rats. In order to clarify the mechanism of bradycardic effect of cyclobuxine D, we examined the changes of the ECG parameters (PR, QRS and R ${\alpha}$ T interval) produced by intravenous injection of cyclobuxine D in anesthetized rats. Cyclobuxine D depressed the contractile force in isolated frog heart and exerted a dose-dependent bradycardic effect in anesthetized rats. Intracerebroventricular injection of cyclobuxine D caused a fall in blood pressure and an increase in heart rate, but those effects were not significant. Cyclobuxine D prolonged the PR interval and RaT interval (${\alpha}$ Tindicates the apex of T), but was without significant effects on the duration of the QRS complex and PRc in urethane anesthetized rats.

• Applied Biological Chemistry
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• v.49 no.3
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• pp.221-226
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• 2006

In order to search anti-obesity agents, the methanol extracts of 155 herbal medicines were screened using with pancreatic lipase, which is involved in conversion of triglycerol to fatty acid. Among the tested medicinal plants, methanol extracts of Amsonia elliptica, Arecae pericarpium, Biota orientalis, Cinnamomum cassia, Curcuma aromatia, Elsholtzia ciliate, Glycyrrhiza uralensis, Mucunae Caulis, Rhus javanica, and Rubus coreanus showed potent inhibition at final concentration of $200\;{\mu}g/ml$ on pancreatic lipase activity. All of them were extracted into chloroform fraction. The relative inhibitory activities against pancreatic lipase by orlistat, the chloroform fraction of Arecae pericarpium and Cinnamomum cassia were 89, 80 and 80%, respectively. These results demonstrated that the screened medicinal plants could be develop as the effective lipase inhibitors in preventing and ameliorating obesity of human beings.

• The Korean Journal of Mycology
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• v.47 no.3
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• pp.259-269
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• 2019

Brown spot and sheath rot of rice are caused by fungal pathogens such as Curvularia lunata, Cochliobolus miyabeanus, and Sarocladium oryzae, and cause losses such as reduced rice yield and quality, which is an enormous problem with serious long-term effects. To search biological control agents of phytopathogenic fungi, five kinds of useful Bacillus-like isolates which are excellent in extracellular enzyme activity and produce siderophore were selected from paddy soil of Sunchang in Korea. The selected isolates were tested for excellent antifungal activity against three of the phytopathogenic fungi that frequently occur in rice, and JSRB 177 strain had the most excellent antifungal activity. Based on the experimental results, JSRB 177 is finally selected as a candidate for biological control and identified to Bacillus subtilis through 16S rRNA sequence analysis. In addition, physiological characteristics of JSRB 177 confirmed by analysis of carbohydrate fermentation patterns and enzyme production ability. Based on the above results, JSRB 177 is expected to be used as a biological control agent for the rice pathogenic fungi. In the future, further studies related to industrialization such as port test and establishment of mass production process are needed.

• Food Science and Preservation
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• v.18 no.3
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• pp.390-396
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• 2011

Ginger (Zingiber officinale) is a well-known herb that is widely consumed as spice for the flavoring of foods. As part of our continuing search for bioactive materials, the in vitro pancreatic lipase inhibition and antioxidant properties of an aqueous ethanolic extract of Z. officinale were investigated. The total phenolic content was determined using a spectrophotometric method. The antioxidant efficacies of the extract was studied with radical scavenging assays using DPPH and $ABTS^+$ radicals. Further more, the antiobesity effect of the extract was evaluated by porcine pancreatic lipase assay. In particularly, the pancreatic lipase inhibitory activity of the ethyl acetate (EtOAc)-soluble portion from Z. officinale was significantly higher than that of the other solvent-soluble portions. The results suggest that Z. officinale may have therapeutic potential that may be useful in development of an anti-obesity agent or its precursors.

• Korean Chemical Engineering Research
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• v.47 no.2
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• pp.220-229
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• 2009

Strain improvement and morphology investigation in bioreactor cultures were undertaken in suspended cultures of Phellinus linteus mycelia for mass production of protein-bound polysaccharides(soluble ${\beta}$-D-glucan), a powerful immuno-stimulating agent. Phellineus sp. screened for this research was identified as Phellinus linteues through ITS rDNA sequencing method and blast search, demonstrating 99.7% similarity to other Phellinus linteus strains. Intensive strain improvement program was carried out by obtaining large amounts of protoplasts for the isolation of single cell colonies. Rapid and large screening of high-yielding producers was possible because large numbers of protoplasts ($1{\times}10^5{\sim}10^6\;protoplasts/ml$) formed using the banding filtration method with the cell wall-disrupting enzymes could be regenerated in relatively high regeneration frequency($10^{-2}{\sim}10^{-3}$) in the newly developed regeneration medium. It was demonstrated that the strains showing high performances in the protoplast regeneration and solid growth medium were able to produce 5.8~6.4%(w/w) of ${\beta}$-D-glucan and 13~15 g/L of biomass in stable manners in suspended shake-flask cultures of P. linteus mycelia. In addition, cell mass increase was observed to be the most important in order to enhance ${\beta}$-D-glucan productivity during the course of strain improvement program, since the amount of ${\beta}$-D-glucan extracted from the cell wall of P. linteus mycelia was almost constant on the unit biomass basis. Therefore we fully investigated the fungal cell morphology, generally known as one of the key factors affecting cell growth extent in the bioreactor cultures of mycelial fungal cells. It was found that, in order to obtain as high cell mass as possible in the final production bioreactor cultures, the producing cells should be proliferated in condensed filamentous forms in the growth cultures, and optimum amounts of these filamentous cells should be transferred as active inoculums to the production bioreactor. In this case, ideal morphologies consisting of compacted pellets less than 0.5mm in diameter were successfully induced in the production cultures, resulting in shorter period of lag phase, 1.5 fold higher specific cell growth rate and 3.3 fold increase in the final biomass production as compared to the parallel bioreactor cultures of different morphological forms. It was concluded that not only the high-yielding but also the good morphological characteristics led to the significantly higher biomass production and ${\beta}$-D-glucan productivity in the final production cultures.

• Korean Security Journal
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• no.33
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• pp.103-135
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• 2012

The object is that this research searches the relationship of the office given condition actual condition of the country important facility private security guard and job satisfaction degree. In order to grasp and analyze the real state of the country important facility private security guards directly, the questionnaire, that is the general measurement tool, was utilized and the guard whom it works in the airport, the port region and general work place, that is the national important facility of Busan and Ulsan area, was aimed at. The enough survey object was illustrated to the facility and person in charge in the security company and the item was previewed and the total 400 sheets was distributed and 331 sheets (82.8%) except the doubleness subject intention and incongruent questionnaire was utilized for the analysis. The statistic processing of collected data utilized the SPSS version 15.0 the statistical package program through data coding and cleaning process and performed the frequency analysis, reliability analysis, t-test, one way analysis of variance, Pearson analysis, and regression analysis. The relationship of the office given condition actual condition of the guard about the national important facility and job satisfaction degree was classified into the interpersonal relationship, task characteristic, office environment, and complement factor and the difference of the job satisfaction degree according to the general characteristic was verified. If the conclusion obtained through the method of study described in the above looked at, for as to general tendency, the low wages and poor field environment was continued. In the general characteristic, the man was higher than the excitation about the job satisfaction level. As there was lots of the age and the scholarship was low, the age was high. And as there was lots of the career and income, the police of a petition or search and guide staff was high and the job satisfaction degree in which relatively the employee and the other job group is high so that the case of being the former student incidence can be the poorest was shown rather than the facility security agent. As the interrelation analysis result job satisfaction was high, the change of occupation pseudo was low and the organizational commitment degrees was increased. The regression analysis result job satisfaction degree was exposed to reach the meaningful effect on the change of occupation pseudo and organizational commitment. It had an effect on the change of occupation pseudo as the task characteristic and office ambient level was low. It had an effect on the organizational commitment as the extend of satisfaction about the task characteristic and interpersonal relationship, complement, and office ambient level were high. If the research result of this time is integrated, the support of the political system including the interpersonal relationship thesis between top and bottom of the organized I and substantial complement actualization is urgently needed between the office given condition improvement effort in the country important facility defense manpower field and police of a petition and special guard.

• Korean Journal of Environmental Biology
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• v.26 no.1
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• pp.30-35
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• 2008

In order to investigate whether or not CCD-986sk cell line can be affected by Korean Ecklonia stolonifera Okamura, we examined the MTT assay when we treated Korean Ecklonia stolonifera Okamura extract in CCD-986sk human fibroblast cell line. The sample were tested for cell proliferation activity by means of a modification of the MTT assay. Ecklonia stolonifera Okamura extract showed significantly strong cell proliferation activity at the range of from 6.25 mg $mL^{-1}$ to 1.56 mg $mL^{-1}$ compared with control group. And in order to search for inhibition agents of skin melanin formation, we tested for inhibition effect of melanin pigmentation of Korean Ecklonia stolonifera Okamura using Clone M-3 mouse melanocyte cell lines. when we treated the extracts of Ecklonia stolonifera Okamura to the mouse melanocyte cell lines, the sample showed a significantly little formation of melanin pigments compared with control group at the only range of 200 mg $mL^{-1}$. These results suggest that extract of Korean Ecklonia stolonifera Okamura may represents an excellent candidate for inhibition of melanin pigmentation and for protection of human skin aging at in vitro level.

• Korean Journal of Microbiology
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• v.41 no.2
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• pp.99-104
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• 2005

Corynebacterial clones which exert regulatory effects on the expression of the glyoxylate bypass genes were isolated using a reporter plasmid carrying the enteric lacZ fused to the aceB promoter of Corynebacterium glutamicum. Some clones carried common fragments as turned out by DNA mapping technique. Subcloning analysis followed by the measurement of $\beta-galactosidase$ activity in Escherichia coli identified the region responsible for the aceB-repressing activity. Sequence analysis of the DNA fragment identified two independent ORFs of ORF1 and ORF2. Among them, ORF2 was turned out to be responsible for the aceB-repressing activity. ORF1 encoded a 23,216 Da protein composed of 206 amino acids. Sequence similarity search indicated that the ORF may encode a ECF-type $\sigma$ factor and designated sigH. To identify the function of sigH, C. glutamicum sigH mutant was constructed by gene disruption technique and the sigH mutant showed growth retardation as compared to the wild type strain. In addition, the mutant strain showed sensitivity to oxidative-stress generating agent plumbagin. This result imply that sigH is probably involved in the stress response occurring during normal cell growth.