• Journal of the Korean Magnetic Resonance Society
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• v.16 no.2
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• pp.111-121
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• 2012

The spin-lattice relaxation times, $T_1$, and spin-spin relaxation times, $T_2$, of the $^{27}Al$ and $^{87}Rb$ nuclei in $RbAl(CrO_4)_2{\cdot}2H_2O$ crystals were investigated. The presence of only one resonance line for the $^{27}Al$ nuclei indicates that the results in a dynamical averaging of the crystal electric field that produces a cubic symmetry field. The changes in the temperature dependence of $T_1$ are related to variations in the symmetry of the octahedra of water molecules surrounding $Al^+$ and $Rb^+$. The $T_1$ values for the $^{27}Al$ and $^{87}Rb$ nuclei are different due to differences in the local environments of these ions. We also compared these $^{27}Al$ and $^{87}Rb$ NMR results with those obtained for $RbAl(CrO_4)_2{\cdot}2H_2O$ crystals. The relaxation mechanisms of $RbAl(XO_4)_2{\cdot}nH_2O$ (X=Cr and S) crystals are characterized by completely different NMR behaviors.

• The Korean Nurse
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• v.27 no.1 s.144
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• pp.21-27
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• 1988

• BMB Reports
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• v.49 no.8
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• pp.401-402
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• 2016

S6K1 is a key regulator of cell growth, cell size, and metabolism. Although the role of cytosolic S6K1 in cellular processes is well established, the function of S6K1 in the nucleus remains poorly understood. Our recent study has revealed that S6K1 is translocated into the nucleus upon adipogenic stimulus where it directly binds to and phosphorylates H2B at serine 36. Such phosphorylation promotes EZH2 recruitment and subsequent histone H3K27 trimethylation on the promoter of its target genes including Wnt6, Wnt10a, and Wnt10b, leading to repression of their expression. S6K1-mediated suppression of Wnt genes facilitates adipogenic differentiation through the expression of adipogenic transcription factors PPARγ and Cebpa. White adipose tissues from S6K1-deficient mice consistently exhibit marked reduction in H2BS36 phosphorylation (H2BS36p) and H3K27 trimethylation (H3K27me3), leading to enhanced expression of Wnt genes. In addition, expression levels of H2BS36p and H3K27me3 are highly elevated in white adipose tissues from mice fed on high-fat diet or from obese humans. These findings describe a novel role of S6K1 as a transcriptional regulator controlling an epigenetic network initiated by phosphorylation of H2B and trimethylation of H3, thus shutting off Wnt gene expression in early adipogenesis.

• East Asian mathematical journal
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• v.27 no.3
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• pp.349-372
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• 2011

In this paper we define interval valued (${\in}$, ${\in}{\vee}q$)-fuzzy hquasi-ideals, interval valued (${\in}$, ${\in}{\vee}q$)-fuzzy h-bi-ideals, interval valued ($\bar{\in}$, $\bar{\in}{\vee}\bar{q}$)-fuzzy h-ideals, interval valued ($\bar{\in}$, $\bar{\in}{\vee}\bar{q}$)-fuzzy h-quasi-ideals, interval valued ($\bar{\in}$, $\bar{\in}{\vee}\bar{q}$)-fuzzy h-bi-ideals and characterize different classes of hemirings by the properties of these ideals.

• Communications of the Korean Mathematical Society
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• v.27 no.1
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• pp.69-76
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• 2012

Let R be a ring, and ${\alpha}$ be an endomorphism of R. An additive mapping H : R ${\rightarrow}$ R is called a left ${\alpha}$-multiplier (centralizer) if H(xy) = H(x)${\alpha}$(y) holds for all x,y $\in$ R. In this paper, we shall investigate the commutativity of prime and semiprime rings admitting left ${\alpha}$-multiplier satisfying any one of the properties: (i) H([x,y])-[x,y] = 0, (ii) H([x,y])+[x,y] = 0, (iii) $H(x{\circ}y)-x{\circ}y=0$, (iv) $H(x{\circ}y)+x{\circ}y=0$, (v) H(xy) = xy, (vi) H(xy) = yx, (vii) $H(x^2)=x^2$, (viii) $H(x^2)=-x^2$ for all x, y in some appropriate subset of R.

• Journal of Ginseng Research
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• v.27 no.3
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• pp.129-134
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• 2003

When ginsenoside $R_{*}$b1/ and $R_{b2}$ were anaerobically incubated with human fecal microflora, these ginsenosides were metabolized to compound K (IH-901). When ginsenoside $R_{g3}$ was anaerobically incubated with human fecal microflora, the ginsenoside $R_{g3}$ was metabolized it to ginsenoside $R_{h2}$. Among ginsenosides, IH-901 and 20(S)-ginsenoside $R_{h2}$ exhibited the most potent cyotoxicity against tumor cells: 50% cytotoxic concentrations of IH-901 in the media with and without fetal bovine serum (FBS) were 27.1-31.6 $\mu$M and 0.1-0.61 $\mu$M, and those of 20(S)-ginsenoside $R_{h2}$ were 37.5->50 and 0.7-7.1 $\mu$M, respectively. The cytotoxic potency of ginsenosides was IH-901>20(S)-ginsenoside R $h_{h2}$》20(S)-ginsenoside $R_{g3}$>ginsenoside $R_{b1}$(equation omitted) $R_{b2}$.EX>$R_{b2}$./.

• The Korean Journal of Mycology
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• v.27 no.6 s.93
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• pp.383-385
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• 1999

Effects of temperature and initial pH of the medium on production of citric acid from cheese whey permeate by Aspergillus niger were investigated. A. niger was cultivated at four different temperatures (27, 30, 33, $36^{\circ}C$) and four different pHs (2, 3, 4, 5) for 15 days. During the fermentation the concentrations of lactose and citric acid in the culture broth were measured. The maximum production of citric acid which was 33.9 g/l (68.26% yield based on lactose utilized) was obtained at $33^{\circ}C$ and pH 3. The production of citric acid was not much affected by shaking speed. However, the shaking speed was found to influence the form of pellets during cell growth.

• Bulletin of the Korean Chemical Society
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• v.27 no.4
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• pp.539-544
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• 2006

Proton transfer reactions and ion-molecule reactions of bifunctional ethanes of $H_2NCH_2CH_2NH_2$, $H_2NCH_2CH_2OH$, and $HOCH_2CH_2OH$ were studied using Fourier transform mass spectrometry (FTMS). The rate constants for proton transfer reactions between the fragment ions and neutral molecules were obtained from the temporal variation of the ion abundances. The rate constants were consistent with the heats of reaction. The fastest proton transfer reactions were the reactions of $CH_2N^+$, $CHO^+$, and $CH_3O^+$ for $H_2NCH_2CH_2NH_2$, $H_2NCH_2CH_2OH$, and $HOCH_2CH_2OH$, respectively. The $[M+13]^+$ ion was formed by the ion-molecule reaction between $H_2C=NH_2 ^+$ or $H_2C=OH^+$ and the neutral molecule. The major product ions generated from the ion-molecule reactions between the protonated molecule and neutral molecule were $[2M+H]^+$, $[M+27]^+$, and $[M+15]^+$.

• Molecules and Cells
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• v.27 no.5
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• pp.533-538
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• 2009

Heat shock protein 27 (Hsp27) is a molecular chaperone protein which regulates cell apoptosis by interacting directly with the caspase activation components in the apoptotic pathways. With the assistance of the Tat protein transduction domain we directly delivered the Hsp27 into the myocardial cell line, H9c2 and demonstrate that this protein can reverse hypoxia-induced apoptosis of cells. In order to characterize the contribution of Hsp27 in blocking the two major apoptotic pathways operational within cells, we exposed H9c2 cells to staurosporine and cobalt chloride, agents that induce mitochondria-dependent (intrinsic) and -independent (extrinsic) pathways of apoptosis in cells respectively. The Tat-Hsp27 fusion protein showed a greater propensity to inhibit the effect induced by the cobalt chloride treatment. These data suggest that the Hsp27 predominantly exerts its protective effect by interfering with the components of the extrinsic pathway of apoptosis.

• ALGAE
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• v.27 no.2
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• pp.95-108
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• 2012

Using genetic sequencing (COI-5P, LSU, $rbc$L) to elucidate their phylogenetic positions and then morphological characters to distinguish each from existing species, three procumbent species, including two novel species, from warm temperate Northern Hemisphere waters are added to the recently resurrected genus $Halopeltis$ J. Agardh: $H.$ $adnata$ (Okamura) comb. nov. from Korea, $H.$ $pellucida$ sp. nov. from Bermuda and $H.$ $willisii$ sp. nov. from North Carolina, USA. Prior to these reports, the genus was confined to the Southern Hemisphere and tropical equatorial waters of the Northern Hemisphere although the latter records lack molecular confirmation. These three additional species join the six known species presently residing in $Halopeltis$.