• Korean Journal of Mathematics
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• v.5 no.1
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• pp.61-74
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• 1997

Let $d$ be a positive integer with $d\not{\equiv}2$ mod 4, and let $K=\mathbb{Q}({\zeta}_{pd})$ for S an odd prime $p$ such that $p{\equiv}1$ mod $d$. Let $K_{\infty}={\bigcup}_{n{\geq}0}K_n$ be the cyclotomic $\mathbb{Z}_p$-extension of $K=K_0$. In this paper, explicit generators for the Tate cohomology group $\hat{H}^{-1}$($G_{m,n}$ are given when $d=qr$ is a product of two distinct primes, where $G_{m,n}$ is the Galois group Gal($K_m/K_n$) and $C_m$ is the group of cyclotomic units of $K_m$. This generalizes earlier results when $d=q$ is a prime.

• Bulletin of the Korean Chemical Society
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• v.22 no.2
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• pp.183-188
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• 2001

Ionic conjugated polymer, poly(2-ethynyl-N-propargylpyridinium bromide), was prepared by the cyclopolymerization of 2-ethynyl-N-propargylpyridinium bromide on using various transition metal catalysts, or by thermal methods without adding catalyst. The polymerization of 2-ethynyl-N-propargylpyridinium bromide catalyzed by PdCl2 gave the resulting polymers in relatively high yields. The polymer structure was characterized by various instrumental methods to confirm the conjugated polymer backbone structure carrying cumulated pyridine moiety. The polymers prepared by PdCl2 in DMSO or m-cresol were completely soluble in DMF, DMSO, and formic acid. The inherent viscosities of the resulting polymers were in the range of 0.07-0.19 dL/g. Thermal properties of the polymers were also discussed.

• Bulletin of the Korean Chemical Society
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• v.26 no.5
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• pp.786-790
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• 2005

A new ternary strontium germanium nitride, ${\beta}-Sr_2GeN_2$, was obtained as single crystal from constituent elements in molten Na. It crystallizes in space group Cmca (No. 64) with a = 5.441(1) $\AA$, b = 11.377(2) $\AA$, c = 12.229(2) $\AA$, and Z = 8. Its crystal structure is closely related to that of polymorphic companion, ${\alpha}-Sr_2GeN_2$, both of which contain isolated bent anions of ${GeN_2}^{4-}$.

• East Asian mathematical journal
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• v.37 no.1
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• pp.87-95
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• 2021

Let K be an imaginary quadratic field with ��K its ring of integers. For a positive integer N, let K(N) be the ray class field of K modulo N��K, and let ��N be the field of meromorphic modular functions of level N whose Fourier coefficients lie in the Nth cyclotomic field. For each h ∈ ��N, we construct a ray class invariant as its special value in terms of the extended form class group, and show that the invariant satisfies the natural transformation formula via the Artin map in the sense of Siegel and Stark. Finally, we establish an isomorphism between the extended form class group and Gal(K(N)/K) without any restriction on K.

• The Korean Journal of Food And Nutrition
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• v.10 no.3
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• pp.407-413
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• 1997

The antimutagenic mechanism of cinnamaldeyde on mutagenesis induced by 4-nitroquinoline-1-oxide(4-NQO) and N-metyl-N'-nitro-N-nitrosoguanidine (MNNG) was investigated in various DNA repair-deficient strains, E. coli B/r and K-12 series. Cinnamaldehyde did not show any effects not only on the $\beta$-galactosidase activities of GW1060 and GW1103(recA441) which synthesizes $\beta$-galactosidase consitutively at 41$^{\circ}C$ but also on that of GW1107[lexA51 (Def)] in which the SOS response always occur. These results suggest that cinnamaldehyde dose not change the function of RecA which positively controls the SOS response as well as not acting as the repressor like LexA. In addition, no inhibitory effect of cinnamaldehyde was observed on the growth of Trp+ revertant and the delay of viable cell growth was also not found by adding cinnamaldehyde. Despite the decrease in the number of revertants, a significant increase in survival of 4-NQO treated cells was observed in E. coli WP2s(uvrA), ZA159($\Delta$uvrB) and TK603(uvrA). But these effects disappeared in excision-proficient strain WP2(uvrA+) and lexA-deficient strains(CM561 and CM611). The enhancement of survival was not found in WP67(uvrA polA) deficient in polymerase I which ligates the gap between complementary DNA. From the above results, we assume that cinnamaldehyde might show antimutagenic effect by enhancing an error-free recombinational repair system.

• Korean Journal of Materials Research
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• v.11 no.8
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• pp.655-660
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• 2001

Surface photovoltage spectroscopy was used to study $In_{0.5}(Ga_{1-x}Al_x)_{0.5}P/GaAs$ grown by metalorganic chemical vapor deposition(MOCVD). Energy gap related transition in GaAs and $In_{0.5}(Ga_{1-x}Al_x)_{0.5}P$ were observed. By measuring the frequency dependence of $In_{0.5}(Ga_{1-x}Al_x)_{0.5}P/GaAs$, we observed that SPV line shape does not chance, whereas the amplitude change. This results is due to the difference in the lifetimes of the photocarriers in GaAs and in $In_{0.5}(Ga_{1-x}Al_x)_{0.5}P$. We also have evaluated the parameters that describe the temperature dependences of the band gap.

• The Korean Journal of Physiology and Pharmacology
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• v.15 no.5
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• pp.251-258
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• 2011

Here we have investigated how lactosylceramide (LacCer) modulates gene expression of adhesion molecules in TNF-${\alpha}$ and IFN ${\gamma}$ (CM)-stimulated astrocytes. We have observed that stimulation of astrocytes with CM increased the gene expression of ICAM-1 and VCAM-1. D-Threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol (PDMP) and N-butyldeoxynojirimycin (NBDNJ), inhibitors of glucosylceramide synthase (GLS) and LacCer synthase (galactosyltransferase, GalT-2), inhibited the gene expression of ICAM-1 and VCAM-1 and activation of their gene promoter induced by CM, which were reversed by exogenously supplied LacCer. Silencing of GalT-2 gene using its antisense oligonucleotides also attenuated CM-induced ICAM-1 and VCAM-1 expression, which were reversed by LacCer. PDMP treatment and silencing of GalT-2 gene significantly reduced CM-induced luciferase activities in NF-${\kappa}B$, AP-1, GAS, and STAT-3 luciferase vectors-transfected cells. In addition, LacCer reversed the inhibition of NF-${\kappa}B$ and STAT-1 luciferase activities by PDMP. Taken together, our results suggest that LacCer may play a crucial role in the expression of ICAM-1 and VCAM-1 via modulating transcription factors, such as NF-${\kappa}B$, AP-1, STAT-1, and STAT-3 in CM-stimulated astrocytes.

• Bulletin of the Korean Chemical Society
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• v.26 no.10
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• pp.1543-1548
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• 2005

Two isostructural new alkaline earth germanium nitrides, $Sr_6Ge_5N_2\;and\;Ba_6Ge_5N_2$, were obtained as single crystals from constituent elements in molten Na. They both crystallize in space group $P_{mmn}$ (No. 59) with a = 4.0007(8), b = 17.954(3), c = 9.089(2) $\AA$, Z = 2, and a = 4.1620(2), b = 18.841(1), c = 9.6116(5) $\AA$, Z = 2, for $Sr_6Ge_5N_2\;and\;Ba_6Ge_5N_2$, respectively. Their crystal structure contains features for both Zintl and nitride phases: zigzag anionic chain of $_{\infty}Ge^{2-}$, and dumbbell-shaped bent anion of ${GeN_2}^{4-}$. Counter cations of Sr or Ba wrap these anionic units in a channel-like arrangement. Unlike in other germanium nitrides, bond lengths of both Ge-N arms of the ${GeN_2}^{4-}$, are same in $Sr_6Ge_5N_2\;and\;Ba_6Ge_5N_2$.

• Proceedings of the Korean Vacuum Society Conference
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• 2006.08a
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• pp.143-143
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• 2006

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.11
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• pp.4991-4998
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• 2016

Objective: This research was conducted to explore mechanisms behind the potency of quercetin in inhibiting colon cancer induced in an experimental model. Materials and Methods: Forty adult male rats of Wistar strain were distributed into 4 groups; a negative control group, a colon cancer bearing group, a quercetin-treated group and a 5-fluorouracil (5-FU)-treated group. Serum TAG72 and GAL3 levels were quantified by ELISA. Colonic Wnt5a and Axin-1 gene expression was estimated by PCR. In addition, colonic tissues were subjected to immunohistochemical examination of Bax expression and histological investigation of histopathological alterations. Results: Quercetin elicited significant reduction in serum TAG72 and GAL3 levels, in addition to significant suppression of colonic Wnt5a gene expression and amplification of colonic Axin-1 gene expression. Also, it caused moderate positive reaction for Bax in mucosal epithelium. Conclusion: The present research provides experimental evidence about the activity of quercetin in the colon cancer of rats. Inhibitory effects on cancer development might be ascribable to regulatory action on Wnt signaling and induction of apoptosis.