• Journal of Electrochemical Science and Technology
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• v.9 no.4
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• pp.301-307
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• 2018

The current study fabricated magnetic functional reduced graphene oxide (MFRGO) by relying on ${FeCl_4}^-$ magnetic anion confined to cationic 1-methyl imidazolium. Furthermore, for improving the electrochemical performance of conductive polymer, hybrid poly ortho aminophenol (POAP)/ MFRGO films have then been fabricated by POAP electropolymerization in the presence of MFRGO nanorods as active electrodes for electrochemical supercapacitors. Surface and electrochemical analyses have been used for characterization of MFRGO and POAP/ MFRGO composite films. Different electrochemical methods including galvanostatic charge discharge experiments, cyclic voltammetry and electrochemical impedance spectroscopy have been applied to study the system performance. Prepared composite film exhibited a significantly high specific capacity, high rate capability and excellent cycling stability (capacitance retention of ~91% even after 1000 cycles). These results suggest that electrosynthesized composite films are a promising electrode material for energy storage applications in high-performance pseudocapacitors.

• Ceramist
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• v.21 no.3
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• pp.302-308
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• 2018

This work reported the trends of bioceramic materials for beauty-care applications with the several represent examples - tone-up, sun-care and anti-pollution cosmetics. The development of cosmetic techniques was discussed and reviewed with various ceramic hybrid materials. Moreover, we also reported the preparation and application of functional cosmetics with silicified liposome particles as a good make-up material for controlled release with natural compounds. The homogeneous loading and highly controlled-release formulation with porous and silicified ceramic liposome ceramic materials were discussed.

• Bulletin of the Korean Chemical Society
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• v.26 no.4
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• pp.589-593
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• 2005

The solvation free energy of proton in methanol was calculated by B3LYP flavor of density functional calculations in combination with the Poisson-Boltzmann continuum solvation model. In order to check the adequacy of the computation level, the free energies of clustering in the gas phase were compared with the experimental data. The solvents were taken into account in a hybrid manner, i.e. one to five molecules of methanol were explicitly considered while other solvent molecules were represented with an implicit solvation model.

• Proceedings of the Zoological Society Korea Conference
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• 2000.10a
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• pp.275.2-276
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• 2000

No Abstract, See Full Text

• Polymer Science and Technology
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• v.21 no.5
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• pp.447-458
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• 2010

• Polymer Science and Technology
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• v.21 no.5
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• pp.459-465
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• 2010

• Nonlinear Functional Analysis and Applications
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• v.27 no.3
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• pp.499-512
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• 2022

In this paper, we construct an iteration scheme involving a hybrid pair of the Suzuki generalized nonexpansive single-valued and multi-valued mappings in a complete CAT(0) space. In process, we remove a restricted condition (called end-point condition) in Akkasriworn and Sokhuma's results [2] in Banach spaces and utilize the same to prove some convergence theorems. The results in this paper, are analogs of the results of Akkasriworn et al. [3] in Banach spaces.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2002.10a
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• pp.18-25
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• 2002

The pikromycin biosynthetic system in Streptomyces venezuleae is unique for its ability to produce two groups of antibiotics that include the 12-membered ring macrolides methymycin and neomethymycin, and the 14-membered ring macrolides narbomycin and pikromycin. The metabolic pathway also contains two post polyketide-modification enzymes, a glycosyltransferase and P450 hydroxylase that have unusually broad substrate specificities. In order to explore further the substrate flexibility of these enzymes a series of hybrid polyketide synthases were constructed and their metabolic products characterized. The plasmid-based replacement of the multifunctional protein subunits of the pikromycin PKS in S. venezuelae by the corresponding subunits from heterologous modular PKSs resulted in recombinant strains that produce both 12- and 14-membered ring macrolactones with predicted structural alterations. In all cases, novel macrolactones were produced and further modified by the DesVII glycosyltransferase and PikC hydroxylase leading to biologically active macrolide structures. These results demonstrate that hybrid PKSs in S. venezuelae can produce a multiplicity of new macrolactones that are modified further by the highly flexible DesVII glycosyltransferase and PikC hydroxylase tailoring enzymes. This work demonstrates the unique capacity of the S. venezuelae pikromycin pathway to expand the toolbox of combinatorial biosynthesis and to accelerate the creation of novel biologically active natural products. The polyketide backbone of rifamycin B is assembled through successive condensation and ${\beta}$-carbonyl processing of the extender units by the modular rifamycin PKS. The eighth module, in the RifD protein, contains nonfunctional DH domain and functional KR domain, which specify the reduction of the ${\beta}$-carbonyl group resulting in the C-21 bydroxyl of rifamycin B. A four amino acid substitution and one amino acid deletion were introduced in the putative NADPH binding motif in the proposed KR domain encoded by rifD. This strategy of mutation was based on the amino acid sequences of the corresponding motif of the KR domain of module 3 in the RifA protein, which is believed dysfunctional, so as to introduce a minimum alteration and retain the reading frame intact, yet ensure loss of function. The resulting strain produces linear polyketides, from tetraketide to octaketide, which are also produced by a rifD disrupted mutant as a consequence of premature termination of polyketide assembly. Much of the structural diversity within the polyketide superfamily of natural products is due to the ability of PKSs to vary the reduction level of every other alternate carbon atom in the backbone. Thus, the ability to introduce heterologous reductive segments such as ketoreductase (KR), dehydratase (DH), and enoylreductase (ER) into modules that naturally lack these activities would increase the power of the combinatorial biosynthetic toolbox. The dehydratase domain of module 7 of the rifamycin PKS, which is predicted to be nonfunctional in view of the sequence of the apparent active site, was replaced with its functional homolog from module 7 of rapamycin-producing polyketide synthase. The resulting mutant strain behaved like a rifC disrupted mutant, i.e., it accumulated the heptaketide intermediate and its precursors. This result points out a major difficulty we have encountered with all the Amycolatopsis mediterranei strain containing hybrid polyketide synthases: all the engineered strains prepared so far accumulate a plethora of products derived from the polyketide chain assembly intermediates as major products instead of just analogs of rifamycin B or its ansamycin precursors.

• Korean Journal of Breeding Science
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• v.41 no.1
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• pp.1-8
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• 2009

This study was carried out to breed and develop high quality and functional nutrient tomato with multi disease resistance as well as a stable growing adaptation for fresh market usage under protected plastic houses cultivation. The materials were used 5 inbred lines and their 6 hybrids of large tomato group, which have been bred and developed from 1999 to 2007 in Division of Plant Resource Department of Chungnam National University. Fruit weight showed hybrid vigor effect that $F_1$ hybrids weighed more than their parent lines, fruit shape formed three type of oblate, deep oblate and globe shape, in firmness and pericarp thickness have got a high significant correlation, inbred DN611 line was measured the most firm fruit with 6.04 mm pericarp thickness. In fruit color at maturity, pink color crossed to red color appeared all red fruit color in the $F_1$ hybrids, it means red skin color is a dominant gene compared to pink skin color is a recessive gene in tomato, while between fruit skin color and shoulder part color showed no any co-relationship. The sugar content and titratable acid of $F_1$ hybrids inherited an intermediate data of their parent lines, the flavor of KP543 inbred line and the hybrid (JB535 x KP543) revealed the better taste with high brix and proper titratable acid content$^{*}$. In beta carotene content DN611 line showed 2~3 times higher than other materials so that its 3 hybrids contained an increased level of beta carotene, lycopene content was not so much difference among inbred lines and $F_1$ hybrids, of them MD508 contained higher of 8.72 mg and hybrid (JB535 x JA517) had 8.05 mg lycopene content per 100 g fruit, overall pink skin color and red skin color measured a higher lycopene content than yellow and orange skin color at ripe stage. In disease resistance test by PCR marker for Fusarium race2 (I2), Nematode (Mi1), ToMV ($Tm2^2$), Cladosporium (Cf9), (JB535 x JA517) hybrid have got multi-resistance with homozygote band in Nematode, ToMV, Cladosporium and heterozygote band in Fusarium race2. Through this breeding program we could select high quality and functional nutrient with multi resistant $F_1$ hybrids and inbred lines in tomato which are two best hybrids (JB535 x MD508), (JB535 x JA517), additionally developed high beta carotene inbred line DN611 and increased the level of lycopene inbred line MD508. These results will be very useful to make a high quality tomato variety continuously.

• Polymer(Korea)
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• v.31 no.1
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• pp.25-30
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• 2007

The characteristics of crosslinking and physical properties in partially crosslinked waste high density polyethylene (HDPE) were studied by introducing reactive melt processing with perbutyl peroxide (PBP). It was found that impurities in waste HDPE affected the crosslinking kinetics. Decrease in density and heat of fusion were observed in partially crosslinked HDPE while its melt viscosity increased. It was explained that impurities in waste HDPE enhanced the crosslinking compared to pure HDPE As a result, dramatic mechanical property improvement was achieved in the waste HDPE by crosslinking reaction.