• Bulletin of the Korean Chemical Society
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• 제26권2호
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• pp.233-237
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• 2005

Cyclopentadiene compounds, 2-[CR'R(OMe)]-1,3-Me$_2C_5H_3$ (R, R' = 2,2'-biphenyl, 2) and 2-[CR'R(OSiMe$_3$)]-1,3-Me$_2C_5H_3$ (R, R' = 2,2'-biphenyl, 3; R = ph, R' = ph, 4; R = 2-naphthyl, R' = H, 5) are readily synthesized from 2-bromo-3-methoxy-1,3-dimethylcyclopentene (1). Reaction of the cyclopentadienes with Ti(NMe$_2$)$_4$ in toluene results in clean formation of the cyclopentadienyl tris(dimethylamido)titanium complexes, which are transformed to the trichloride complexes, 2-[CR'R(OMe)]-1,3-Me$_2C_5H_2$}TiCl$_3$ (R, R' = 2,2'-biphenyl, 6) and {2-[CR'R(OSiMe$_3$)]-1,3-Me$_2C_5H_2$}TiCl$_3$ (R, R' = 2,2'-biphenyl, 7; R = ph, R' = ph, 8; R = 2-naphthyl, R' = H, 9). Attempts to form C1-bridged Cp/oxido complexes by elimination of MeCl or Me$_3$SiCl were not successful. X-ray structures of 6, 7 and an intermediate complex {2-[Ph$_2$C(OSiMe$_3$)]-1,3-Me$_2C_5H_2$}TiCl$_2$(NMe$_2$) (10) were determined.

• 한국결정학회지
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• 제15권1호
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• pp.9-17
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• 2004

Trigonal system에 屬한 25個 space group들 中 18個는 hexagonal axes만을 나타내는 lattice letter p로 表示되고, 나머지 7個의 rhombohedral space groups R3(146), $R\={3}$(148), R32(155), R3m(160), R3c(161), $R\={3}m$(166), $R\={3}c$(167)은 첫째 3개의 lattice points (0, 0, 0), (2/3, 1/3, 1/3), (1/3, 2/3, 2/3)를 갖는 hexagonal cell in obverse setting과 둘째 primitive rhombohedral cell의 두 가지로 表示된다. 本 論文에서는 space group $R\={3}c$(167)에 대하여 論한 後 이 space group에 屬한 化合物인 tris(1,2,3,4-tetraphenylbuta-1,3-dienyl)cyclotriphosphazene, $C_{84}H_{60}N_3P_3$의 構造를 hexagonal 및 rhombohedral cell 의 양쪽으로 糾明하여 發表하였다.

• 대한수학회보
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• 제58권6호
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• pp.1341-1354
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• 2021

Let r ≥ 2, and let k_i ≥ 2 for 1 ≤ i ≤ r. Mixed van der Waerden's theorem states that there exists a least positive integer w = w(k₁, k₂, k₃, …, k_r; r) such that for any n ≥ w, every r-colouring of [1, n] admits a k_i-term arithmetic progression with colour i for some i ∈ [1, r]. For k ≥ 3 and r ≥ 2, the mixed van der Waerden number w(k, 2, 2, …, 2; r) is denoted by w₂(k; r). B. Landman and A. Robertson [9] showed that for k < r < $\frac{3}{2}$(k - 1) and r ≥ 2k + 2, the inequality w₂(k; r) ≤ r(k - 1) holds. In this note, we establish some results on w₂(k; r) for 2 ≤ r ≤ k.

• Asian-Australasian Journal of Animal Sciences
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• 제24권1호
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• pp.125-129
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• 2011

The aim was to determine the relationship between muscle structure and meat quality traits in neuromuscular compartments (NMCs: R1, R2, R3, R4) of pig semitendinosus muscle. Barrows from the INTA-MGC genetic line (Argentina) were slaughtered at 100 kg body weight. In each NMC the following parameters were determined: the fibre types I, IIA, IIX and IIB by immunohistochemistry, the fibre cross sectional area (FCSA), the pH of meat after 24 h post-mortem ($pH_{24}$), instrumental meat tenderness (WB) and colour ($L^*$, $a^*$, $b^*$). There were significant differences in the following: $L^*$ (R1 = R4$a^*$ (R1>R4>R2 = R3), $b^*$ (R1 = R4R1 = R3 = R4), $pH_{24}$ (R1 = R4>R2 = R3). The relative percentages of FCSA were as follows: I (R4>R1>R3>R2), IIA (R1>R4>R3>R2), IIX (R1 = R2 = R3 = R4) and IIB (R2>R3>R1>R4). The correlation values were statistically significant between IIB and WB (R1 and R4, $r_s$ = 0.66), (R2 and R3 $r_s$ = 0.74), IIB and $L^*$ (R1 and R4 $r_s$ = 0.84), IIX and $L^*$ without discriminating NMCs. Our data suggest that the NMC where the sampling takes place is important for determining meat quality traits because of the heterogeneity of the whole muscle.

• 대한화장품학회지
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• 제41권2호
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• pp.143-150
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• 2015

본 연구는 3,7-diarylpyrazolo [1,5-${\alpha}$]pyrimidines의 효과적인 one-pot regioselective 합성을 보여준다. 더욱이, 그 유도체는 뛰어난 CB1R 저해 활성을 나타냈다. 3,7-position에 diaryl group이 치환된 pyrazolo [1,5-${\alpha}$]pyrimidine은 CB1R 후보로서 가능성 있는 pharmacophore이다.

• Journal of Ginseng Research
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• 제27권3호
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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>$R_{b2}$./.

• 한국산학기술학회논문지
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• 제5권5호
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• pp.454-457
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• 2004

부분응답 최대유사 (PRML: partial response maximum likelihood) 검출기법은 수직 자기기록 채널에 적합한 검출기법이다. PRML 시스템에 RLL(Run Length Limited)을 결합하여 저 복잡도 검출기법을 제안하였다. 모의 실험의 결과 R=2/3 변조 부호를 사용한 PR(1,2,3,4,3,2,1)ML과 PR(1,2,3,3,2,1)ML이 각각 K=3, 4에서 가장 우수한 성능을 보였다. 그러나, K=3인 경우 R=2/3 PR(1,1,1,1)ML은 R=2/3 PR(1,2,3,3,2,1)ML에 비해 매우 적은 복잡도를 갖지만 약 1.5dB의 성능열화만을 보이는 것을 알 수 있었다. K=4 일때는 R=1 PR(1,2,,2,1)ML은 R=2/3 PR(1,2,3,4,3,2,1)ML과 비교하여 휠씬 적은 복잡도를 가지면서 2dB이내의 성능 열화를 가짐을 확인 할 수 있었다.

• Asian Pacific Journal of Cancer Prevention
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• 제13권6호
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• pp.2605-2610
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• 2012

Background: Studies investigating the association of 2R/3R polymorphism in the thymidylate synthase 5'-untranslated enhanced region (TSER) and colorectal cancer (CRC) risk have reported conflicting results. Thus, a meta-analysis was performed to summarize the data on the potential association. Methods: Pubmed, Embase and CBM databases were searched for all available studies. Links between the TSER 2R/3R polymorphism and CRC risk were estimated by odds ratios (ORs) with 95% confidence intervals (CIs). Results: Seven case-control studies with a total of 2723 cases and 4030 controls were included in this meta-analysis. The results showed that the 3R variant of TSER 2R/3R polymorphism contributes to CRC risk in two comparison models (OR 3R vs. 2R =1.10, 95%CI 1.02-1.18, P = 0.015; OR Homozygote comparison model = 1.22 1.04-1.43, 95%CI 1.04-1.43, P = 0.012). Subgroup analyses by ethnicity further demonstrated a contribution in Caucasians with three comparison models (OR 3R vs. 2R = 1.10, 95%CI 1.02-1.19, P = 0.015; OR Homozygote comparison model = 1.21, 95%CI 1.03-1.41, P = 0.019; OR Recessive comparison model = 1.18, 95%CI 1.05-1.33, P = 0.008). However, the association in the Asian population was still uncertain due to the limited data (all P values were more than 0.05). Conclusions: Our meta-analysis suggests that the 3R variant of Thymidylate synthase 5'-untranslated enhanced region 2R/3R polymorphism contributes to gastric cancer risk in the Caucasian population, while any association in Asian populations needs further study.

• 대한수학회보
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• 제53권3호
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• pp.885-902
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• 2016

In this paper we begin the study of $L_k$-2-type hypersurfaces of a hypersphere ${\mathbb{S}}^{n+1}{\subset}{\mathbb{R}}^{n+2}$ for $k{\geq}1$ Let ${\psi}:M^3{\rightarrow}{\mathbb{S}}^4$ be an orientable $H_k$-hypersurface, which is not an open portion of a hypersphere. Then $M^3$ is of $L_k$-2-type if and only if $M^3$ is a Clifford tori ${\mathbb{S}}^1(r_1){\times}{\mathbb{S}}^2(r_2)$, $r^2_1+r^2_2=1$, for appropriate radii, or a tube $T^r(V^2)$ of appropriate constant radius r around the Veronese embedding of the real projective plane ${\mathbb{R}}P^2({\sqrt{3}})$.

• 대한화학회지
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• 제41권3호
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• pp.150-156
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• 1997

Bulgecinine의 선구물질인 (4S,5R)-1-acetyl-2-formyl-5-benzyloxymethyl-4-pyrrolidinol (15)을 diacetone-D-glucose로부터 합성하였다. Barton 탈산소화 반응, C-5에서의 반전, $-N_3$ 도입과 환원 및 C-2에서의 고리 형성을 통해 bulgecinine의 핵심 중간체인 두 고리 화합물 (6R)-6-Ο-benzyloxymethyl-(3R)-3-methoxy-2-oxa-5-azabicyclo-[2,2,1]heptane (13)을 합성하였다. 화합물 13을 N-아세틸화 후 산가수분해하여 얻은 bulgecinine 선구물질은 토토머화가 수반되어 (2S,4S,5R)-pyrrolidinol 유도체 15와 함께 (2S,4S,5R)-부분 입체 이성질체도 얻어졌다.