• Proceedings of the Korean Vacuum Society Conference
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• 1996.02a
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• pp.158-158
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• 1996

• Proceedings of the Korean Biophysical Society Conference
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• 1996.07a
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• pp.21-21
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• 1996

The hyperthermostable protein, rubredoxin from Pyrococcus furiosus is 53-residue protein with a three-stranded anti-parallel $\beta$-sheet and several loops. To investigate the effect of changes of electrostatic and hydrophobic interactions on the structure and dynamic property of P. furiosus rubredoxin, molecular dynamics simulations in water were performed on three mesophilic rubredoxins, P, furiosus rubresoxin, and 5 mutants of P. furiosus rubredoxin. (omitted)

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.655-658
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• 2004

This study was performed to verify the possibility of the integrity estimation of the bridge substructure focusing on the dynamic property change of concrete pier with penetration depths using experimental modal analysis. As a result of the impact vibration test, it is found that scour reduces the stiffness of the foundation, and measurement the accelerance residue and natural frequency can be used for the estimation of the integrity index.

• Resources Recycling
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• v.4 no.4
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• pp.12-15
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• 1995

In this paper, some representative waste tire pyrolysis were investigated together with the analysis of the problems associated with the commercialization of various waste tire treatment technologies. Also, R & D results on recovering the oil from the pyrolysis of waste tires, when waste oil was used as a heating medium, were summarized in this study. Experimental results show that the present pyrolysis process has both lower pyrolytic temperature and higher pyrolysis rate than usual one and that the quality of the product oil and residue obtained was relatively even with large availability.

• Journal of the Korean Institute of Telematics and Electronics
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• v.24 no.3
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• pp.420-424
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• 1987

The model reduction methods of the linear time invariant continuous systems are proposed. The energy dispersion method is used to obtain the model denominator. And the model numerator is found by the modified residue method or the time moment matching method. The methods suggested are compared with the method suggested by Lucas and give good results.

• The Korean Journal of Physiology and Pharmacology
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• v.24 no.3
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• pp.277-286
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• 2020

Polycystic kidney disease 2-like-1 (PKD2L1), also known as polycystin-L or TRPP3, is a non-selective cation channel that regulates intracellular calcium concentration. Calmodulin (CaM) is a calcium binding protein, consisting of N-lobe and C-lobe with two calcium binding EF-hands in each lobe. In previous study, we confirmed that CaM is associated with desensitization of PKD2L1 and that CaM N-lobe and PKD2L1 EF-hand specifically are involved. However, the CaM-binding domain (CaMBD) and its inhibitory mechanism of PKD2L1 have not been identified. In order to identify CaM-binding anchor residue of PKD2L1, single mutants of putative CaMBD and EF-hand deletion mutants were generated. The current changes of the mutants were recorded with whole-cell patch clamp. The calmidazolium (CMZ), a calmodulin inhibitor, was used under different concentrations of intracellular. Among the mutants that showed similar or higher basal currents with that of the PKD2L1 wild type, L593A showed little change in current induced by CMZ. Co-expression of L593A with CaM attenuated the inhibitory effect of PKD2L1 by CaM. In the previous study it was inferred that CaM C-lobe inhibits channels by binding to PKD2L1 at 16 nM calcium concentration and CaM N-lobe at 100 nM. Based on the results at 16 nM calcium concentration condition, this study suggests that CaM C-lobe binds to Leu-593, which can be a CaM C-lobe anchor residue, to regulate channel activity. Taken together, our results provide a model for the regulation of PKD2L1 channel activity by CaM.

• Journal of Integrative Natural Science
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• v.10 no.1
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• pp.1-6
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• 2017

Demand for a new anti-malarial drug has been dramatically increasing in the recent years. Plasmodium falciparum enoyl-acyl carrier protein reductase (PfENR) plays a vital role in fatty acid elongation process, which now emerged as a new important target for the development of anti-microbial and anti-parasitic molecules. In the present study, 19 compounds namely alginic acid, atropine, chlorogenic acid, chrotacumine A & B, coenzyme $Q_1$, 4-coumaric acid, curcumin, ellagic acid, embelin, 5-O-methyl embelin, eugenyl glucoside, glabridin, hyoscyamine, nordihydroguaiaretic acid, rohitukine, scopolamine, tlatlancuayin and ursolic acid were evaluated on their docking behaviour on P. falciparum enoyl-acyl carrier protein reductase (PfENR) using Auto dock 4.2. The docking studies and binding free energy calculations exhibited that glabridin gave the highest binding energy (-8.07 kcal/mol) and 4-coumaric acid in contrast showed the least binding energy (-4.83 kcal/mol). All ligands except alginic acid, ellagic acid, hyoscyamine and glabridin interacted with Gln409 amino acid residue. Interestingly four ligands namely coenzyme $Q_1$, 4-coumaric acid, embelin and 5-O-methyl embelin interacted with Gln409 amino acid residue present in both chains (A & B) of PfENR protein. Thus, the results of this present study exhibited the potential of these 19 ligands as P. falciparum enoyl-acyl carrier protein reductase (PfENR) inhibitory agents and also as anti-malarial agents.

• Analytical Science and Technology
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• v.28 no.3
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• pp.175-181
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• 2015

Cyantraniliprole, which is an ananthranilic diamide insecticide that was developed by the DuPont Corporation, was registered in the Republic of Korea in 2012. It offers exceptional insecticidal activity on a broad range of Lepidopera, Coleoptera, Diptera, and Isoptera. The maximum residue limits are set to pepper, peach, apple, sweet pepper, welsh onion, and so on (0.2~2.0 mg/kg). Therefore, an analytical method for determining cyantraniliprole residue in agricultural products was developed to ensure food safety. In previous studies, welsh onions were among vegetables included in the allium species, which is a representative plant with sulfur organic compounds. In this study, the analytical method was developed and evaluated for the elimination of sulfur compounds from the test solution of allium species during pesticide residue analysis. In order to inactivate the enzyme allinase and produce sulfur compounds, sample extraction was made in the base state pH 10 by reducing the activity of the enzyme. The recoveries of the developed method ranged from 81.9% to 83.2%, and the relative standard deviations were less than 10%. Therefore, based on the results, the method developed in this study is accurate and appropriate for use in cyantraniliprole determination. It will be used as the official method for managing the safety of cyantraniliprole residues in agricultural products.

• The Korean Journal of Pesticide Science
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• v.14 no.2
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• pp.104-109
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• 2010

We investigated five neonicotinoid pesticide residues (acetamiprid, clothianidin, imidacloprid, thiacloprid, thiamethoxam) in fruit vegetables and estimated the exposure of neonicotinoid pesticide residue through fruit vegetable consumption using a deterministic approach. Two hundred forty samples of eight fruit vegetables cultivated in Korea were analyzed for their pesticide residue contents. Acetamiprid had the highest detection frequency and the highest residue level in pepper. However, all pesticide levels detected didn't exceed national MRLs. The results using a deterministic approach showed that for chronic and acute study of all neonicotinoid pesticide residues, the exposure was about 50 times lower than toxicological endpoint values. It is necessary to understand that the exposure assessment in this study using a probabilistic approach should be regarded as a important knowledge in the decision-making process.

• Molecules and Cells
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• v.40 no.4
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• pp.299-306
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• 2017

The transcriptional activator AphB has been implicated in acid resistance and pathogenesis in the food borne pathogens Vibrio vulnificus and Vibrio cholerae. To date, the full-length AphB crystal structure of V. cholerae has been determined and characterized by a tetrameric assembly of AphB consisting of a DNA binding domain and a regulatory domain (RD). Although acidic pH and low oxygen tension might be involved in the activation of AphB, it remains unknown which ligand or stimulus activates AphB at the molecular level. In this study, we determine the crystal structure of the AphB RD from V. vulnificus under aerobic conditions without modification at the conserved cysteine residue of the RD, even in the presence of the oxidizing agent cumene hydroperoxide. A cysteine to serine amino acid residue mutant RD protein further confirmed that the cysteine residue is not involved in sensing oxidative stress in vitro. Interestingly, an unidentified small molecule was observed in the inter-subdomain cavity in the RD when the crystal was incubated with cumene hydroperoxide molecules, suggesting a new ligand-binding site. In addition, we confirmed the role of AphB in acid tolerance by observing an aphB-dependent increase in cadC transcript level when V. vulnificus was exposed to acidic pH. Our study contributes to the understanding of the AphB molecular mechanism in the process of recognizing the host environment.