• Korean Journal of Microbiology
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• v.41 no.4
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• pp.239-245
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• 2005

Transformation-Associated Recombination (TAR) cloning technique allows selective isolation of chromosomal regions and genes from complex genomes. The procedure requires knowledge of relatively small genomic sequences that reside adjacent to the chromosomal region of interest. This technique involves homologous recombination during yeast spheroplast transformation between genomic DNA and a TAR vector that has 5' and 3' gene targeting sequences. In this study, we examined the effect of non-homologous spacing sequence in target hooks on homologous recombination using a plasmid model system. The efficiency of homologous recombination between the modified his3-TRP1-his3 fragments and HlS3 gene on plasmid were analyzed by the characterization of $Ura^+$ transformants. The numbers of $Ura^+$ transformant showed same level when seven different modified his3-TRP1-his3 fragments were used. But the percentage of positive recombinants. $Trp^+His^-$, dramatically decreased when used the modified his3-TRP1-his3 fragments contained incorrect spacing of nonhomologous region. As a result, we suggest that incorrect spacing inhibits the homologous recombination between target hook and substrate DNA. Therefore, we should consider the correct spacing in target hook when the target hook are used for cloning of orthologue gene.

• Herbal Formula Science
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• v.16 no.1
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• pp.117-130
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• 2008

Korean traditional medicine has been used for the treatment of the various diseases based on both oriental medicinal theory and clinical trials. Thus, the prescriptions of Korean traditional medicine would be useful for the development of new therapeutics. This research focuses on the fundamental study in Korean traditional prescriptions for the development of new hepatoprotective agents. We found two prescriptions. Injinho-Tang and Osumogwa-Tang, showed the significant DPPH free radical scavenging and hepatoprotective effect, respectively. It is well-known that free radical scavenging effect is related to the prevention of various pathological events including liver injury. This paper deals with hepatoprotective effects on tacrine-induced cytotoxicity in Hep G2 cells, free radicals scavenging on both DPPH and superoxide of above two prescriptions. Hot water extract of Injinho-Tang did not show the significant hepatoprotective effect on tacrine-induced cytotoxicity in Hep G2 cells, however, it shows the significant scavenging effects for both DPPH and superoxide radicals. On the other hand, all of the hot water extracts of constituent herbal drugs in Injinho-Tang exhibited the promising protective effect on tacrine-induced cytotoxicity in Hep G2 cells. Of these, water extract of Rhei Rhizoma showed the most prominent effect on tacrine-induced cytotoxicity in Hep G2 cells. Bioassay-guided fractionation of Rhei Rhizoma extract has furnished four compounds, and their chemical structures have been identified by comparison of their spectral data with those of literature as chrysophanol (1), emodin (2), 3,5-dihydroxy-4'- methoxystilbene (3), and rhapontigenin (4), respectively. Among the isolated compounds, compounds 2-4 revealed the significant hepatoprotective effect in vitro when their $EC_{50}$ values compare with that of silybin, as a positive control. It also exhibited that emodin possessed the most hepatoprotective effect among these active compounds. In case of Osumogwa-Tang, its hot water extract showed the moderate protective effect on tacrine-induced cytotoxicity in Hep G2 cells. Hot water extract of Chaenomelis Fructus, one of the constituent herbal drug of this prescription, exhibited the significant hepatoprotective effect with $EC_{50}$ value of $7.8{\pm}0.1\;{\mu}g/ml$, however, it showed strong cytotoxicity in Hep G2 cells above the concentration of $25\;{\mu}g/ml$. It was revealed that both hot water extract of Evodiae Fructus and its butanol soluble fraction showed the moderate hepatoprotective effect but concentration-dependent activity in Hep G2 assay system. Two quinolone alkaloids, evocarpine and dihydroevocarpine, also tested for their hepatoprotective effects on tacrine-induced cytotoxicity in Hep G2 cells, however, these two compounds derived from the Evodiae Fructus as the major constituents did not show in vitro hepatoprotective effect. From these results, it would be necessary to further isolation of its hepatoprotective compounds from the butanol soluble fraction of the hot water extract of Evodiae Fructus.

• The Korean Journal of Elementary Counseling
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• v.6 no.1
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• pp.117-140
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• 2007

This study is to know the effect of drama therapy on the sociality of isolated children. To achieve this goal, the following hypothesis was built. Hypothesis I. Dramatherapy program will improve the sociality of isolated children. I -1. Dramatherapy program will improve in cooperation. I -2. Dramatherapy program will improve in independency. I -3. Dramatherapy program will improve in sociability. I -4. Dramatherapy program will improve in law-abiding. To test this hypothesis, the social and emotional isolation test was conducted in 190 children consisting of fifth-grader from N elementary school located in Busan to select 28 children whose founded to be isolated; among these children, eight who wanted to participate in the program were positioned at the experimental group and other eight who didn't want to do and who demonstrated the range of marks similar to the experimental group were positioned at the control group. The dramatherapy program was based on the theory by Robert Landy (2002), Jennings (2003) and Phil Jones (2005) to improve the sociality of isolated children and was implemented in a total of 15 sessions, two sessions a week after school. To test the effect of the program, A modified test paper by Suh, Poongyeon (1991) with the content of testing sociality into a test paper of human nature for elementary school students to be made by Jeong, Bummo (1971) was used which consists of four sub-factors: cooperation, independency, sociability, law-abiding. As a quantitative analysis, Mann-Whitney Test were analyzed for experimental and control groups. As a qualitative analysis, the interaction patterns among student were analyzed on he basis of video tapes. The tool of observe the interaction patterns among student was Interaction Process Analysis System which was made by Bales (1970). This study obtained the following result First, the drama therapy had meaningful effect on the sociality of the sociality of isolated children. But the quantitative change of the sociality test conclusion was showed meaningfully and positive social behavior was increased in periodical process analysis. Second, in the Interaction Process Analysis(IPA) affirmative interactions increased and negative interactions decreased.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.1
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• pp.84-89
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• 2011

A Xenon Feed System (XFS) has been developed for hall-effect thruster to small satellite space-propulsion system applications. The XFS delivers low pressure gas to the Anode and Cathode of thruster head unit from a xenon storage tank. Accurate throttling of the propellant mass flow rate is independently required for each channel of the thruster head unit. The mass flow rate to each channel is controlled using the accumulator tank pressure regulation through a micron orifice and isolation valve. This paper discusses the Xenon Feed System design including the component selections, performance estimation and functional test.

• Korean Journal of Pharmacognosy
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• v.44 no.1
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• pp.10-15
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• 2013

This study was carried to establish a simple isolation and purification method of ginsenoside $F_1$ from leaves of Panax ginseng and was to evaluate the inhibitory effect of purified ginsenoside $F_1$ on the activities of elastase and tyrosinase. The content of ginsenoside $F_1$ was 90-fold higher in leaves than in root of ginseng. Ginsenoside $F_1$ was isolated from EtOAc fraction between EtOAc and alkalized water of 80% EtOH extract after remove of hydrophobic components. The 50% inhibitory concentration ($IC_{50}$) of ginsenoside $F_1$ on elastase activity and tyrosinase activity was 1.07 mM and 1.81 mM, respectively. Especially, inhibitory effect of ginsenoside $F_1$ on tyrosinase activity was higher than that of arbutin ($IC_{50}$; 2.20 mM). These results indicate that ginsenoside $F_1$ have a potential for industrial cosmetic materials.

• Journal of the Korean Society for Nondestructive Testing
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• v.21 no.5
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• pp.542-548
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• 2001

A robust, accurate, broad-band, alternating current sensor using fiber-optics is being developed as a part of optical over current protection relay system. The sensor uses the Faraday effect in optical fiber and polarimetric measurements tc sense electrical current. The current sensing coil consists of a length of twisted optical fiber and Faraday rotator mirror to suppress the linear birefringence effect. Due to its single-ended closed path structure, it can not only be easily installed to the target with great isolation from other fields in the vicinity, but the sensitivity can be increased by using multiple turns. This paper reports on the theoretical backgrounds of the sensor design and the preliminary experimental results.

• Journal of Drive and Control
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• v.13 no.3
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• pp.8-14
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• 2016

This study describes the effect of the critical pressure ratio of a control valve on the performance of an air spring system composed of an air spring, auxiliary chamber, control valve and mass in order to suggest a more efficient design for an air spring system. The critical pressure ratio of the control valve is assumed to have a fixed value, but the critical pressure ratio of the control valve is known to have various values between 0.05 and 0.6, and the effect of the variation of the critical pressure ratio on the performance of the air spring system has not yet been reported. The analysis derives nonlinear and linear governing equations of the air spring system, including the critical pressure ratio of the control valve. This simulation study is presented to show that the impedance and transmissibility characteristics of the air spring system change due to variations in the critical pressure ratio of the control valve as well as its sonic conductance. As a result, the critical pressure ratio of the control valve should be maintained as large as possible to improve the vibration isolation characteristics of the air spring system.

• Korean Journal of Pharmacognosy
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• v.36 no.1 s.140
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• pp.56-59
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• 2005

Urease plays an important role in the urea metabolism and the effect of urease activity on human and environment is enormous. For instance, urease acts as a virulence factor of the urinary and gastrointestinal tracts infections in human and animal, being involved in kidney stone formation, catheter encrusatation, pyelonephritis, ammonia encephalopathy, hepatic coma, and urinary tract infections. Widespread urease activity in soil induces a plant damage due to ammonia toxicity and pH increase. Therefore, urease activity regulation through urease inhibitors would lead to an enhanced efficiency of urea nitrogen uptake in plants and to the improved therapeutic strategies for ureolytic bacterial infections. To search for new inhibitory compounds on urease activity from herbs, MeOH extracts of herbs were screened. Among of them, the MeOH extracts of Areca catechu exhibited an excellent inhibitory effect on urease activity. Two compounds were isolated from the ethyl acetate fraction by the activity guided fractionation. Their chemical structures were identified as (+)-catechin(compound I) and allantoin(compound II) by spectroscopic evidence, respectively. Compound I showed a stronger inhibitory effect on urease activity than compound II.

• Korean Journal of Pharmacognosy
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• v.43 no.4
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• pp.297-301
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• 2012

In the course of screening for antioxidant compounds by measuring the radical scavenging effect on 1,1-diphenyl-2-picrylhydrazyl (DPPH), a total extract of the twigs of Taxillus delavayi (Loranthaceae) was found to show potent radical scavenging activity. Subsequent activity-guided fractionation of the methanolic extract led to the isolation of two phenolic compounds, catechin (1) and galloyl catechin (2), as active principles. Their structures were elucidated by spectroscopic studies. These two compounds showed the significant antioxidative effects on DPPH, and riboflavin- and xanthin-originated superoxide quenching activities. And these two compounds also showed strong nitric oxide radical scavenging effects. In riboflavin- and xanthin-originated superoxide quenching activities and nitric oxide radical scavenging effect, compound 2 showed better antioxidant activities than vitamin C.

• Journal of the Korea Safety Management & Science
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• v.15 no.2
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• pp.1-7
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• 2013

Based on a literature review regarding shift work, it is recognized that it has an adverse effect on workers' health. Especially, the night shift rather than the day shift imposes severe disorders on workers, which are indicated to dyssomnia, maladaptation to social life, and health problems such as gastroenteric trouble, cardiovascular diseases and depression. As the shift work can be explainable by using workers' labor ability necessarily to maintain company business consistently, it does not consider biorhythm, active mass and health condition of workers Actually duration of shit work would deprive workers of fundamental life rights by causing physical and mental effects. As a result of reviewing previous case studies related to effect of work pattern (day shift and night shift) on workers' health, an incidence of physical diseases like dyssomnia, gastroenteric trouble, cardiovascular diseases and premature delivery was higher in shift workers than normal workers. Additionally the incidence of mental disorders such as busy brain, social isolation, depression and work stress was also higher in shift workers than normal workers. These adverse physical and mental problems were intensified to night shift workers compared to day shift workers. Considering current various reports and study results, it is recommended that the shift work, especially the night work pattern, should not apply to contemporary work situation for sustaining workers' health condition constantly.