• Bulletin of the Korean Chemical Society
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• v.32 no.9
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• pp.3219-3222
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• 2011

Three types of ${\beta}$-ketoacyl acyl carrier protein synthase (KAS) are important for overcoming the bacterial resistance problem. Recently, we reported the discovery of a antimicrobial flavonoid, YKAF01 (3,6-dihydroxyflavone), which exhibits antibacterial activity against Gram-positive bacteria through inhibition of ${\beta}$-ketoacyl acyl carrier protein synthase III (KAS III). In this report, we suggested that YKAF01 can be an inhibitor ${\beta}$-ketoacyl acyl carrier protein synthase I (KAS I) with dual inhibitory activity for KAS I as well as KAS III. KAS I is related to the elongation of unsaturated fatty acids in bacterial fatty acid synthesis and can be a good therapeutic target of designing novel antibiotics. We performed docking study of Escherichia coli KAS I (ecKAS I) and YKAF01, and determined their binding model. YKAF01 binds to KAS I with high binding affinity ($2.12{\times}10^6$) and exhibited an antimicrobial activity against the multidrug-resistant E. coli with minimal inhibitory concentration (MIC) value of 512 ${\mu}g$/mL. Further optimization of this compound will be carried out to improve its antimicrobial activity and membrane permeability against bacterial cell membrane.

• Bulletin of the Korean Chemical Society
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• v.32 no.5
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• pp.1645-1649
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• 2011

[ ${\beta}$ ]Ketoacyl acyl carrier protein synthase I (KAS I) is involved in the elongation of unsaturated fatty acids in bacterial fatty acid synthesis and a therapeutic target of designing novel antibiotics. In this study, we performed receptor-oriented pharmacophore-based in silico screening of E. coli KAS I (ecKAS I) with the aim of identifying novel inhibitors. We determined one pharmacophore map and selected 8 compounds as candidates ecKAS I inhibitors. We discovered one antimicrobial compound, YKAe1008, N-(3-pyridinyl) hexanamide, displaying minimal inhibitory concentration (MIC) values in the range of 128-256 ${\mu}g/mL$ against MRSA and VREF. YKAe1008 was subsequently assessed for binding to ecKAS I using saturation-transfer difference NMR spectroscopy. Further optimization of this compound will be carried out to improve its antimicrobial activity and membrane permeability against bacterial cell membrane.

• Journal of the Korean Society of Costume
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• v.40
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• pp.25-35
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• 1998

This thesis is a study of Kas ya, robes of buddhist monk, which is having peculiarity among human clothes. I kept my attention mainly on the symbolism of the color of Kas ya. To elucidate this, I chose the principle of T -chi and Yin-yang and Wu-shing as a frame-work of interpretation. In the first place, the original meaning of Kas ya mean a name of peculiar color. The concrete names of the color are color of persimmons juice, brown, yellow tinged with red, radish brown, non-primary color etc. The main motive to dye three robes of buddhist monk from white or primary color to the color of Kas ya was to differentiate buddhist monks from heathen or laymen. Therefore, as luxurious and primary colored cloths was donated to the buddhist monks, they are necessary to discolor them. Accordingly. they established 'non-primary color' as well-mate one for a ascetic. The non-primary color is called discolored color' as a result of discoloring primary colors. The discolored color is a synonym of Kas ya and the process of discoloring is necessary for making robes of buddhist monk. Secondly, discoloring means to mash five primary color. That is say, the process of discoloring means to return five primary colors back to 'profoundity·abstruseness·obscurity, namely darkness' as the source of them. Darkness as a condition amalgamated and not appeared all materials is the source and at the same time the terminus of all colors. Therefore, color of Kas ya symbolizes 'profound color' as the ultimate meaning of discoloring. Thirdly, discoloring garments of buddhist monk symbolize to destroy evil passions and haughtiness arising in ascetic's mind as well as means don't attach to the shaped materials'. Fourthly, discoloring means to return 'color'. namely 'all kinds of shaped material' to the inherent nature. Process of discoloring means to reture to the empty. nya. nya essentially do not make any colors, but over and over again come into being and become extinct as becoming colors. R pa, by one time Yin and the other time Yang'. R pa, color is a metaplasia of nya and nya is discoloring one of all colors. Then, discoloring means R pa is nya, R pa is nya at the same time and Because this is another expression of Dharma the original meaning of Kas ya symbolize true robes. Consequently, Kas ya means truth and beyond time and space do not be changed and conserve the color of the first till now.

• Applied Biological Chemistry
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• v.49 no.3
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• pp.192-195
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• 2006

For the development of a qualitative PCR detection method for genetically modified perilla (Perilla frutescens), perilla species-specific gene, KAS-I (Beta-ketoacyl-ACP synthase I), was selected and validated as suitable for the use as an endogenous reference gene in perilla. Primer specificity was first tested by the means of qualitative PCR analysis. The primer pair Pfru3-F/R amplifying the perilla endogenous gene, KAS-I, gave rise to an amplicon 95 bp. No amplified product was observed when DNA samples from 15 different plants were used as templates. Qualitative PCR detection method was assayed with vitamin E-enriched GM Perilla developed in Korea. For the qualitative PCR detection method, the construct-specific detection primer pairs were constructed. The primer pair TMTO-F/R amplifying the junction region of TMT (${\gamma}$-tocopherol methyltransferase) gene and OCS (Octopine synthase) terminator introduced in GM perilla gave rise to an amplicon 148 bp.

• Journal of environmental and Sanitary engineering
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• v.21 no.1 s.59
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• pp.21-34
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• 2006

To investigate anti-HIV-1 activity of water soluble chitosans, sulfated chitosan derivatives were prepared in mild condition. Various sulfated chitosan derivatives (N-3,6-O-S-chitosan, N-desulfated 3,6-O-S-chitosan, 3,6-O-S-chitin, and 3,6-O-sulfated-N-(o-carboxybenzoyl) chitosan) were synthesized with sulfurtrioxidepyridene complex in pyridine solvent. Characterization of the sulfated chitosan derivatives was carried out by $^{13}C$ NMR and IR spectroscopies. To observe ionic reaction properties, pKas of the sulfated chitosan derivatives and chitosan of low molecular weight were estimated by potentiometric titration. The sulfated chitosan derivatives had high water solubility, pKas (pKa : 7.7) of N-3,6-O-S-chitosan and N-desulfated 3,6-O-S-chitosan were increased than pKa of water insoluble chitosan (pKa : 6.2), These results suggest the participation of electrostatic interaction of amino and sulfate groups on the sulfated chitosans. Anti-HIV-1 drugs, such as AZT, ddC, and ddI for anti-HIV activity had higher selective index compared with SCB-chitosan but N-3,6-O-S-chitosan has shown higher selective index compared with ddC and ddI as HIV drugs.. These results suggest that sulfated chitosan derivatives were expected as an anti-HIV drug with differential driving force mechanism against some nucleoside analogs drug in the future.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.8
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• pp.694-701
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• 2018

Civil aircraft noise certification standard is based on the ICAO Annex 16 Vol. 1. And, the standard uses A-Weighted SPL, EPNL and SEL method depending on the aircraft category. Korean noise standards, KAS 36 and other nation's CS 36 and FAR 36 noise standards were developed and revised according to the international noise standards, ICAO Annex 16. And, the national noise requirements are equivalent each other. The small airplane noise certification requires only take-off noise level with A-Weighted SPL in dB(A) unit. The first Korean aircraft noise certification was performed for the KC-100 certification in August 2012 with Korean authority and U.S. FAA. The noise certification requires much knowledge and experience in flight tests and noise data processing. In this study, the noise test requirements, test conditions and data correcting methods are shown with the test examples.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.1
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• pp.57.3-57.3
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• 2019

Recently, there have been discussions among national observatories in East Asia about the possibility of EAO and the Subaru observatory forming a partnership. The official EAO-Subaru partnership can make the powerful wide-field observation capabilities of Subaru available to Korean astronomers through EAO, and also can serve as an excellent platform to gather astronomers in East Asia together for flourishing regional collaboration activities. A working group has been formed to outline the framework of the EAO-Subaru partnership, and the working group report has been prepared. In this talk, I will explain the proposed partnership framework in the working group report. Inputs are very welcome from KAS members about the proposed framework.

• Korean Institute of Interior Design Journal
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• no.25
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• pp.176-183
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• 2000

The purpose of this study is to show the implications of the term "digital architecture," which are realized in the current architecture. To do this, I first observe its theoretical background and then analyze the works of Marcos Novak, Kas Oosterhuis, and Lars Spuybroek, all of whom are called the typical digital architects. In particular, this study tries to show that the digital architects are introducing the non-Euclidean multi-dimensions and the cyberspace and applying the notions of liquid architecture, transarchitecture, body-building, and body-building, and body-motorized system into their works. Finally, I conclude that the digital architecture anticipates the direction of the future architecture, in which the virtual world is merged with the real world, the digital space is realized in the real space, and the human is completely harmonized with nature.th nature.

• Proceedings of the KIEE Conference
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• 1996.11a
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• pp.95-98
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• 1996

Response speed of generator/control system kas increased with the aid of the development of power electronics. Even though it is desirable to enhance response speed for the control system(AVR/Gov) of generator itself, in case a certain generator/control system with high response excitation system is connected with bulk power system, terminal voltage and active power of some generators can oscillate with adjoining generators or near area when even a little of disturbance take place. PSS(Power System Stabilizer) is used to damp rotor swing by adding the supplementary signal in phase with speed. As the stable AVR response is very important before PSS is installed, modeling and analysis of generator/control system was performed. Next we have analysed PSS response of Hanlim's gas turbine by transmission line open/close test.

• Korean Journal of Soil Science and Fertilizer
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• v.16 no.1
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• pp.42-49
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• 1983

In order to find out the possibility of predicting fertilizer K requirement from the K supplying capacity of soil, the relative K activity ratio, Kas/kai, the potential buffering capacity of $K^+$ ($PBC^k$ ; the liner regression coefficient) and its activity ratio ($AR^k_o$ ; $^{k+}$/${\sqrt{Ca^{+2}+Mg^{+2}}}$ in mol/l) at ${\delta}K$ = O, in the Q/I relationships of Beckett(1964), were determined for the soils before flooding and the samples taken at heading stage of transplanted rice in pot experiment. These parameters assumed as the K supplying capacity of soils were subjected for the investigation through correlation stady between themselves and other factors such as grain yield or the amounts of $K_2O$ uptake by rice plant at harvest. The results may be summarized as follows; 1. The potassium supplying power of the flooded soil was considered to be ruled by the amounts of exchangeable K before flooding, since there was little change in exchangeable K concentration from no-exchangeable K during the incubation periods of 67 days. 2. The $PBC^k$ values, in soils before flooding were 0.027, 0.014 and 0.009, where as the $AR^k_o{\times}10^{-3}$ values were 9.1, 7.6, and 15.4, respectively, in clay, loamy and sandy loam soils. 3. The $PBC^k$ values, determined in the soil samples taken at heading stage, varied little compared with the values of orignal soil, regardless of those different fertilizer treatments and textures, showing the possibility of using them as a factor for the improvement of soil to increase the efficiency of fertilizer K. 4. The significant yield responses to potassium fertilizer application were observed wherever the $AR^k_o$ values in soil at heading stage drop down to the original $AR^k_o$ values, regardless of any levels of fertilizer application. 5. The higher correlations between the gain yield or the amounts of $K_2O$ uptake and by the use of both soil factors of $PBC^k$ and $AR^k_o$ at heading stage were observed compared with the use of any single factor. 6. The Kas/Kai value in the soil, estimated prior to the experiment, had high possitive correlation with the $AR^k_o$ determined in the soil at heading stage and could be used as a soil factor for predicting potassium fertilizer requirement.