• YAKHAK HOEJI
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• v.16 no.2
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• pp.97-107
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• 1972

Thirty-three Mannich bases of 2,2'-methylene bis(3,4,6-trichlorophenoxyacetic acid) were synthesized as potential antimicrobial agents and tested against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Trichophyton rubrum, Microsporum gypseum, Epidermophyton floccosum, Aspergillus niger and Aspergillus oryzae in vitro. It was found that: 1) Compounds 24 and 22 were active against Staphylococcus aureus and Bacillus subtilis at the concn. of 1 $\mu$g/ml respectively; 2) Compounds 9 and 29 were active against Trichophyton rubrum at the concn. of 2 $\mu$g/ml respectively; 3) Compouns 9 and 30 were active against Microsporum gypseum at the concn. of 2 $\mu$g/ml respectively; 4) Compounds 6,9,13,15,21,28,29,31,33 and 34 were active against Epidermophyton floccosum at the concn. of 1 $\mu$g/ml respectively; 5) Compounds 6,9,18 and 28 were active against Aspergillus niger and Aspergillus oryzae at the concn. of 1 $\mu$g/ml respectively.

• Bulletin of the Korean Chemical Society
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• v.2 no.3
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• pp.112-114
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• 1981

The photocycloaddition reaction of 8-methoxypsoralen with purine and/or pyrimidine bases is studied as a model for the charge transfer interactions of psoralens with DNA bases by the FMO method. The results indicate that, in the case of the molecular complex formation between psoralens and purine and/or pyrimidine bases, the most probable photocycloaddition should occur in the following order: Thy (5,6)<>(3,4) 8-MOP, Cyt(5,6)<>(3,4)8-MOP, Ade (7,8)<>(3,4)8-MOP, Gua(7,8)<>(3,4)8-MOP. The theoretical results for the photocycloaddition reaction are also correlated with the experimental results. The photoadducts between 8-methoxypsoralen and adenine are likely to be C4-cycloadducts through the cycloaddition of 3,4-pyrone double bond of 8-methoxypsoralen to 7,8-double bond of adenine.

• Bulletin of the Korean Chemical Society
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• v.13 no.3
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• pp.240-245
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• 1992

The effect of the addition of sodium dodecyl sulfate (SDS) to a buffered mobile phase (pH 3.4) on the retention of nucleotides, nucleosides and bases was investigated with a polyvinyl alcohol (PVA) column. Depending on the concentration of SDS, two different trends in the retention of nucleosides and bases containing an $NH_2$ group were observed. If the concentration of SDS was less than 5.5 mM, the retention of compounds containing an $NH_2$ group increased as the concentration of SDS in the mobile phase increased. In contrast, if the concentration was greater than 5.5 mM, the retention of compounds containing an $NH_2$ group decreased. Thus, the SDS acted as an ion-pairing reagent at lower concentration but formed micelles at higher concentrations. The retention behavior of the nucleosides and bases in the presence of a micellar concentration of SDS in the mobile phase on the PVA column was compared to the retention behavior on other types of columns.

• Bulletin of the Korean Chemical Society
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• v.21 no.3
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• pp.321-327
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• 2000

Polynucleotide analogues containing pyrimidine (uracil and thynime) bases, $poly[(1'{\beta}-uracil-1-yl-2'.5'-dideoxy-D-glycero-pent-4'-enofuranose)-alt-(maleic$ acid)] (12) and $poly[(1'-{\beta}-thymin-1-yl-2'5'-dideoxy-D-glycero-pent-4'-enofuranose)-alt-(maleic$, acid)] (15), were synthesized by the altermating copolymerization of relevant nucleosied derivatives and maleic anhydride, and the subsequent hydrolysis. The polymers had quite similar structures to the natural polymes and were soluble in water, They showed high hypochromicities up to 49% and excimer fluorescence due to the base stacking, and polyelectrolyte behavior. Since the polymers had compact structrures, depyrimidinations, the release of pyrimidine bases from the polymer backbone, occurred in aqueous solutions with higher rates compared with those of the natural polymers.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.2
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• pp.103-109
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• 2000

Complete senuences of the mitochondrial rRNA Benes were determined among six salmonines in Korean Waters (Brachpmystax lenok, Onoorhpchus keta, O. masou mason, O. mason ishikawae, O. mykiss, and albino mutant of O. mykiss). The purposes of this study were to provide the basic information on levels of mtDNA polymorphism among these species for genetic characterization; discuss phylogentic relationships among three Oncorhynchus sepecies; demonstrate the utility of rRNA gene sequence data as a genetic marker for disringuishinf among Korean salmonines. PCR/direct sequencing data indicated the following consistent results; 1) 12S rRNA genes was 945 bases long in Oncorhynchus species, and 946 bases in B. lenot including one insertion. 2) Of sequence variation in mitochondrial rRNA regions, transitional substitutions were superior to transversion. 3) The significant differences were not shown in the intraspecific variation values in these gene regions. The percentage sequence divergence values were ranged from $0.066 to 0.212{\%}$. 4) The interspecific divergences were greater than the intraspecific variation. Nevertheless, ribosomal RMh genes were more conserved among species than the other mitochondrial genes, and they showed potentiality as an intergenic marker for systematics. In addition, phylogenetic trees, constructed from this data, supported that cherry salmon was closer to chum salmon than to rainbow trout, and that lenok was most distantly related species in six salmonid species.

• Nutrition Research and Practice
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• v.5 no.5
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• pp.396-403
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• 2011

Ceramides (Cer) comprise the major constituent of sphingolipids in the epidermis and are known to play diverse roles in the outermost layers of the skin including water retention and provision of a physical barrier. In addition, they can be hydrolyzed into free sphingoid bases such as $C_{18}$ sphingosine (SO) and $C_{18}$ sphinganine (SA) or can be further metabolized to $C_{18}$ So-1-phosphate (S1P) and $C_{18}$ Sa-1-phosphate (Sa1P) in keratinocytes. The significance of ceramide metabolites emerged from studies reporting altered levels of SO and SA in skin disorders and the role of S1P and Sa1P as signaling lipids. However, the overall metabolism of sphingoid bases and their phosphates during keratinocyte differentiation remains not fully understood. Therefore, in this study, we analyzed these Cer metabolites in the process of keratinocyte differentiation. Three distinct keratinocyte differentiation stages were prepared using 0.07 mM calcium (Ca$^{2+}$) (proliferation stage), 1.2 mM Ca$^{2+}$ (early differentiation stage) in serum-free medium, or serum-containing medium with vitamin C (50 ${\mu}L$/mL) (late differentiation stage). Serum-containing medium was also used to determine whether vitamin C increases the concentrations of sphingoid bases and their phosphates. The production of sphingoid bases and their phosphates after hydrolysis by alkaline phosphatase was determined using high-performance liquid chromatography. Compared to cells treated with 0.07 mM Ca$^{2+}$, levels of SO, SA, S1P, and SA1P were not altered after treatment with 1.2 mM Ca$^{2+}$. However, in keratinocytes cultured in serum-containing medium with vitamin C, levels of SO, SA, S1P, and SA1P were dramatically higher than those in 0.07- and l.2-mM Ca$^{2+}$-treated cells; however, compared to serum-containing medium alone, vitamin C did not significantly enhance their production. Taken together, we demonstrate that late differentiation induced by vitamin C and serum was accompanied by dramatic increases in the concentration of sphingoid bases and their phosphates, although vitamin C alone had no effect on their production.

• Journal of the Korean association of regional geographers
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• v.9 no.3
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• pp.297-313
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• 2003

Problems caused by the U.S. military bases have attracted little attention until recently due to the national security of S.Korea and the peace of North-Eastern Asia, emphasized from the perspective of macro-geopolitics. However, since the political regime has been democratized and political discourses have been liberalized from the 1990s, those problems become a nation-widely serious social issue, though they have been brought about on the local areas. Thus, it can be suggested that micro-geopolitics is highly relevant and significant in approaching the local problems caused by the U.S. military bases, and ultimately resolving the macro-geopolitical problem of longstanding unfair relations in the SOFA and the withdrawal of U.S. troops. This paper aims to consider local problems caused by the U.S. military bases and resolving strategies from the perspective of micro-geopolitics. First of all, it discusses some significance of the micro-geopolitical perspective, as it has been recently emphasized in political geography in considering local problems and politics of life on the basis of place, then looks on empirically criminal and environmental problems caused by the U.S. military bases, analyses the questionnaire date on the perception of local dwellers around the military camps in Nam-gu Daegu, and finally suggests strategies to resolve those problems, which level up from the micro to the macro-scale of geopolitics.

• Bulletin of the Korean Mathematical Society
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• v.39 no.1
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• pp.71-79
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• 2002

In this short note, we find bases of the centers of generic Hecke algebras associated with certain finite Coxeter groups. Our bases are described using the notion of cell datum of Graham and Lehrer, and the notion of norm.

• Journal of the Chungcheong Mathematical Society
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• v.16 no.1
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• pp.81-96
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• 2003

Let ${\sigma}:k{\rightarrow}A{\otimes}B$ be a skew copairing on (A, B), where A and B are Hopf algebras of the same dimension n. Skew dual bases of A and B are introduced. If ${\sigma}$ is an invertible skew copairing then we can give a 2-cocycle bilinear form [${\sigma}$] on $A{\otimes}B$ and define a new Hopf algebra.

• Korean Journal of Mathematics
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• v.22 no.3
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• pp.517-527
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• 2014

In this paper, we study affine transformations of normal bases and give an explicit formulation of the multiplication table of an affine transformation of a normal basis. We then discuss constructions of self-dual normal bases using affine transformations of traces of a type I optimal normal basis and of a Gauss period normal basis.