• Research in Plant Disease
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• v.20 no.3
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• pp.182-188
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• 2014

Because bacterial isolates from only a few genera have been developed commercially as biopesticides, discovery and characterization of novel bacterial strains will be a key to market expansion. Our previous screen using plant bioassays identified 24 novel biocontrol isolates representing 12 different genera. In this study, we characterized the 3 isolates showing the best biocontrol activities. The isolates were Pantoea dispersa WCU35, Proteus myxofaciens WCU244, and Exiguobacterium acetylicum WCU292 based on 16S rRNA sequence analysis. The isolates showed differential production of extracellular enzymes, antimicrobial activity against various fungal or bacterial plant pathogens, and induced systemic resistance activity against tomato gray mold disease caused by Botrytis cinerea. E. acetylicum WCU292 lacked strong in vitro antimicrobial activity against plant pathogens, but induced systemic resistance against tomato gray mold disease. These results confirm that the trait of biological control is found in a wide variety of bacterial genera.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.557-557
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• 2012

Silicatein-${\alpha}$, the enzyme extracted from silica spicules in glass sponges, has been studied extensively in the way of chemistry from 1999, in which the pioneering work by Morse, D. E. - the discovery of the enzymatic hydrolysis in Silicatein-${\alpha}$ - was published. Since its reaction conditions are physiologically favored, synthesis of various materials, such as gallium oxide, zirconium oxide, and silicon oxide, was achieved without any hazardous wastes. Although some groups synthesized oxide films and particles, they have not achieved yet controlled morphogenesis in the reaction conditions mentioned above. With the knowledge of catalytic triad involved in hydrolysis of silicone alkoxide and oligomerization of silicic acid, we designed the novel peptide amphiphiles to not only form self-assembled structure, but also display similar activities to silicatein-${\alpha}$. Designed templates were able to self-assemble into left-handed helices for the peptide amphiphiles with L-form amino acid, catalyzing polycondensation of silicic acids onto the surface of them. It led to the formation of silica helices with 30-50 nm diameters. These results were characterized by various techniques, including SEM, TEM, and STEM. Given the situation that nano-bio-technology, the bio-applicable technology in nanometer scale, has been attracting considerable attention; this result could be applied to the latest applications in biotechnology, such as biosensors, lab-on-a-chip, biocompatible nanodevices.

• The Journal of Korean Academic Society of Nursing Education
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• v.7 no.2
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• pp.207-216
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• 2001

To understand the types of interactions between the nurses' college students and patients, this research used Spradley's Cultural Description Method to carry out his eleven- stage research conduct process : participatory observation, cultural description recording, descriptive observation, category analysis, focus observation, classification analysis, selective observation, components analysis, cultural themes, cultural discovery, and cultural description writing. The research participants were 7 nurses' college students practising at the hospital affiliated to E university, and data were collected from May 2000 through primary and secondary in-depth interviews and observations. The cultural characteristics of the subjects extracted from these results were as follows : 1. The students learned through contacts with patients. 2. The students experienced "Sharing" through interactions with patients. 3. The students showed evasive behaviors in difficult situations. 4. The students paltered when faced with difficult situations. 5. The students did not surrender to the refusals of patients. 6. The students identified their studentship. 7. The students regarded human interaction as 'contact'.

• Journal of The Korean Astronomical Society
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• v.41 no.3
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• pp.59-64
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• 2008

To detect exoplanets and study pulsation of K giant stars, we have observed precise RV (radial velocity) of about 55 early K giant (K0 - K4) stars brighter than V = 5 magnitude since 2003 by using BOES, a high resolution Echelle spectrograph attached to the 1.8 m telescope at BOAO (Bohyunsan Optical Astronomy Observatory). We detected periodic RV variation of KO III star $\beta$ Gem (HD 62509) with a period $P\;=\;596.6\;{\pm}\;2.3$ days and a semi-amplitude $K\;=\;44.8\;{\pm}\;0.7\;ms^{-1}$. If we adopt 1.7 $M_{\odot}$ for the mass of $\beta$ Gem, this yields the minimum mass of the companion m sin i = 2.64 $M_{Jupiter}$. Our results agree well with Hatzes et al. (2006) and Reffert et al. (2006), and confirm their discovery of a planetary object around $\beta$ Gem. We also confirmed about 192 minutes short period stellar oscillation found by Hatzes and Zechmeister (2007). This is the first report of exoplanet detection using BOES and demonstrates that the RV observation using BOES is accurate and stable enough to detect exoplanets around bright K giant stars.

• 한국균학회소식:학술대회논문집
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• 2014.10a
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• pp.23-23
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• 2014

There are many yeast strains have been discovered for industrial usage in global scale. In the point of view for the alcoholic fermentation performance and producing alcoholic beverage products, recently many countries have known about the importance of microorganisms as a valuable resource. Discovered with well performed yeasts have potential industrial application in diverse ways such as foods, beverages, cosmetics, pharmaceutical functions, and so on. In Korea, the yeast research has not been sufficiently performed especially for distilled spirits industry. As a result, not so little manufacturers use exotic yeasts from overseas even included the expensive royalties. Besides of those, to produce distilled spirits, many manufacturers do not use specialized yeast for distilled spirits. Distiller's characterized yeasts such as whisky, brandy, vodka, Japanese shochu and awamori, are all well-known industrialized. For decades, the distillers, except us, have selected, developed, and practised yeasts in accordance with distilled spirits characters. This study is about selection and industrial application of yeasts for the Korean pot distilled spirits. Finally 7 yeast strains were selected among over 1,000 yeasts from the traditional Nuruks, through the essential related tests based on brewing and distilling science. The selected yeasts show the appropriate characteristics of distilled spirits. The result of this study could help our distilled spirits industry be activated and stand independent from the exotic microbes.

• Journal of Magnetics
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• v.2 no.4
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• pp.147-156
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• 1997

An artificially modulated magnetic Co/Pd multilayer is one of the promising candidates for high density magneto-optic (MO) recording media, due to a large Kerr rotation angle in the wavelength of a blue laser beam. However, since multilayer structure, as well as amorphous structure, is a non-equilibrium state in terms of free energy and a MO recording technology is a kind of thermal recording which is conducted around Curie temperature (Tc) of the recording media, when the Co/Pd mulilayer is used for the MO recording media, changes in the magnetic properties are occurred as the amorphous structure do. Therefore, the assessment of the magnetic properties in the Co/Pd multilayer during interdiffusion is crucially important both for basic research and applications. As the parameter of the magnetic properties in this research, saturation magnetization and perpendicular magnetic anisotropy energy of the Co/Pd multilayer are measured in terms of Ar sputtering pressure and heat treatment temperature. Form the results of the research, we find out that the magnetic exchange energy between Co and Pd sublayers strongly affects the changes in the magnetic properties of the Co/Pd multilayers during the interdiffusion in ferromagnetic state. This discovery will provide the understanding of the magnetic exchange energy in the Co/Pd multilayer structure and suggest the operating temperature range for MO recording in the Co/Pd multilayer for the basic research and applications, respectively.

• Journal of Ginseng Research
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• v.34 no.3
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• pp.160-167
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• 2010

Asian ginseng (Panax ginseng) and American ginseng (Panax quinquefolius L.) are the two most recognized ginseng botanicals. It is believed that the ginseng saponins called ginsenosides are the major active constituents in both ginsengs. Although American ginseng is not as extensively studied as Asian ginseng, it is one of the best selling herbs in the US, and has garnered increasing attention from scientists in recent years. In this article, after a brief introduction of the distribution and cultivation of American ginseng, we discuss chemical analysis of saponins from these two ginsengs, i.e., their similarities and differences. Subsequently, we review pharmacological effects of the saponins, including the effects on the cardiovascular system, immune system, and central nervous system as well as the anti-diabetes and anti-cancer effects. These investigations were mainly derived from American ginseng studies. We also discuss evidence suggesting that chemical modifications of ginseng saponins would be a valuable approach to develop novel compounds in drug discovery.

• Journal of Integrative Natural Science
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• v.3 no.1
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• pp.49-53
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• 2010

Molecular docking is a critical event which mostly forms Van der waals complex in molecular recognition. Since the majority of developed drugs are small molecules, docking them into proteins has been a prime concern in drug discovery community. Since the binding pose space is too vast to cover completely, many search algorithms such as genetic algorithm, Monte Carlo, simulated annealing, distance geometry have been developed. Proper evaluation of the quality of binding is an essential problem. Scoring functions derived from force fields handle the ligand binding prediction with the use of potential energies and sometimes in combination with solvation and entropy contributions. Knowledge-based scoring functions are based on atom pair potentials derived from structural databases. Forces and potentials are collected from known protein-ligand complexes to get a score for their binding affinities (e.g. PME). Empirical scoring functions are derived from training sets of protein-ligand complexes with determined affinity data. Because non of any single scoring function performs generally better than others, some other approaches have been tried. Although numerous scoring functions have been developed to locate the correct binding poses, it still remains a major hurdle to derive an accurate scoring function for general targets. Recently, consensus scoring functions and target specific scoring functions have been studied to overcome the current limitations.

• Korean Journal of Plant Resources
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• v.20 no.6
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• pp.491-498
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• 2007

It has been hypothesized that efficient exclusion of methylated retrotransposons and repeated DNA region is one of the rapid and cost-effective approaches for comprehensive gene discovery in large genome size of maize. Three kinds of methylation-sensitive restriction enzymes, HapII, MspI and McrBC, were used to identify the restriction frequency of cytosine methylation sites in maize genome. Roughly 60% of total maize genomic DNA was restricted less than 500bp by McrBC, and the most of restricted small size fraction was composed retrotransposon. In order to validate the efficient construction of gene-rich shotgun library, we compare two gene-rich methyl-filtration shotgun libraries using in vivo and in vitro methyl-filtration system. The size selected DNA fraction by Sau3A-McrBC enzyme treated was very stable and has not appeared modification in E. coli, but most insert DNA size of partially digested with Sau3A were decrease less than 500bp by bacterial methylation-modification system. In compare of retroelements portion, A 44.6% of the sequences were retroelement in unmethyl-filtered library, and the most of them was Copia type, such as Prem, Opie and Ji. The portion of retroelement was drastically decreased to 25% and 20% by in vivo and in vitro filtration system, respectively.

• Journal of Magnetics
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• v.2 no.3
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• pp.86-92
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• 1997

An artificially modulated magnetic Co/Pd multilayer is one of the promising candidates for high density magneto-optic (MO) recording media in the wavelength of a blue laser beam, due to large Kerr rotation angle. However, since the Co/Pd multilayer is a non-equilibrium state in terms of free energy and MO recording is a kind of thermal recording which is conducted around Curie temperature (Tc) of the recording media, the assessment of the thermal stability in the Co/Pd multilayer is crucially important both for basic research and applications. As the parameter of the thermal stability in this research, effective interdiffusion coefficients (Deff) perpendicular to the interface of the Co/Pd multilayers are measured in terms of Ar sputtering pressure and heat treatment temperature. From the results of the research, we find out that the magnetic exchange energy between Co and Pd sublayers strongly affects Deff of the Co/Pd multilayers. This discovery will provide the understanding of the magnetic exchange energy in the effective interdiffusion process of a magnetic multilayer structure and suggest the operating temperature range for MO recording in the Co/Pd multilayer for the basic research and applications, respectively.