• 대한수학회보
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• 제45권1호
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• pp.59-66
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• 2008

Keskin and Harmanci defined the family B(M,X) = ${A{\leq}M|{\exists}Y{\leq}X,{\exists}f{\in}Hom_R(M,X/Y),\;Ker\;f/A{\ll}M/A}$. And Orhan and Keskin generalized projective modules via the class B(M, X). In this note we introduce X-local summands and X-hollow modules via the class B(M, X). Let R be a right perfect ring and let M be an X-lifting module. We prove that if every co-closed submodule of any projective module P contains Rad(P), then M has an indecomposable decomposition. This result is a generalization of Kuratomi and Chang's result [9, Theorem 3.4]. Let X be an R-module. We also prove that for an X-hollow module H such that every non-zero direct summand K of H with $K{\in}B$(H, X), if $H{\oplus}H$ has the internal exchange property, then H has a local endomorphism ring.

• Bulletin of the Korean Chemical Society
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• 제34권2호
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• pp.585-589
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• 2013

Optically active N-benzyl-2-methyl-2H-benzo[b][1,4]oxazin-3(4H)-ones and N-benzyl-2-methyl-2H-benzo[b][1,4]thiazin-3(4H)-ones with potential synthetic and pharmacological interest were prepared via Smiles rearrangement in conventional as well as microwave irradiation conditions in one-pot from inexpensive (S)-2-chloropropionic acid. Most of the compounds displayed good inhibition against Gram positive bacteria and fungi in the antibiotic test.

• 한국식품과학회지
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• 제17권6호
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• pp.426-430
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• 1985

자초(紫草)추출물의 외관상 변색에 영향을 주는 온도와 pH에 대해 조사하였다. 변색은 Hunter치(値)의 차이로 표시 할 수 있으며 자초추출물의 Hunter치(値)는 $50^{\circ}C$ 이상에서 변화하기 시작하고 $60^{\circ}C$ 이상에서는 온도와 상관관계를 이루었다. 온도에 따른 Hunter L, a, b, 치(値)의 변이상관계수는 열처리 시간이 증가함에 따라 감소하였으며, 전체변색의 상관계수는 증가하였다. 66.7% 에탄올로 추출한 추출물을 1시간 열처리 할때 Hunter치(値) 변이 상관계수는 L치(値)의 경우 -0.3696, a치(値)의 경우 -0.4124, b치(値)의 경우 -0.2279, 전체 변색에 있어선 0.5983이었다. 이 때 전체변색의 상관계수는 Hunter L, a, b 각각의 상관계수로부터 직접 계산할 수 있었으며 0.5988로서 거의 비슷한 값을 보여주었다. 한편 pH를 낮추면 Hunter a치(値)는 감도하고 L, b치(値)는 약간 증가하였으나 pH를 증가시키면 pH6.5를 전후로 해서 Hunter L, a, b 치(値) 모두 다 급격히 감소하여 외관상 색깔이 좋지 않았다. 자초(紫草)추출물은 pH가 4.0-6.5일 때 외관상 가장 좋은 '선명한 붉은색'을 나타내었다.

• 한국초전도학회:학술대회논문집
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• 한국초전도학회 2000년도 High Temperature Superconductivity Vol.X
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• pp.61-64
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• 2000

$^{11}$B NMR measurements have been performed to investigate local electronic structure and 4f spin dynamics for TbNi$_2$B$_2$C single crystal. $^{11}$B NMR spectra show three resonance peaks due to the quadrupolar interaction. Shift and linewidth are huge and strongly temperature-dependent. In addition, both are proportional to magnetic susceptibility, indicating that the hyperfine field at the boron site originates from the 4f spins of Tb. $^{11}$B NMR shift and relaxation rates show high anisotropy for field parallel and perpendicular to the c-axis. Anisotropy of the shift and the relaxation rates suggests that the hyperfine field perpendicular to the c-axis is larger.

• 한국물환경학회지
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• 제27권2호
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• pp.194-199
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• 2011

This study has been carried out to evaluate the performance of $PbO_2$ electrode for the purpose of degradation of N,N-Dimethyl-4-nitrosoaniline (RNO, indicator of OH radical), generation of ozone and decolorization of Rhodamine B (RhB) in water. The effect of the applied current (0.2~1.2 A), electrolyte type (NaCl, KCl and $Na_2SO_4$), electrolyte concentration (0.0~2.5 g/L) and solution pH (3~11) were evaluated. Experimental results showed that RhB and RNO removal were increased with the increase of current, NaCl dosage and decrease of pH. Ozone generation tendencies appeared with the almost similar to the RhB and RNO degradation, except of solution pH (Ozone generation was increased with increase of pH). Optimum current for RhB degradation and consumption of electric power was 1.0 A. The RhB degradation with Cl type electrolyte were higher than that with the sulfate type. Optimum NaCl dosage for RhB degradation was 1.0 g/L.

• 대한수학회논문집
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• 제39권3호
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• pp.717-729
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• 2024

Let 𝓑(H) be the algebra of all bounded linear operators on a Hilbert space H with dim(H) > 2. Let 𝒢𝒫(H) be the subset of 𝓑(H) of all generalized projection operators. In this paper, we give a complete characterization of surjective maps 𝚽 : 𝓑(H) → 𝓑(H) satisfying A-𝛌B ∈ 𝒢𝒫(H) ⇔ 𝚽(A) - 𝛌𝚽(B) ∈ 𝒢𝒫(H) for any A, B ∈ 𝓑(H) and 𝛌 ∈ ℂ.

• Bulletin of the Korean Chemical Society
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• 제32권7호
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• pp.2249-2252
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• 2011

Two new carborane complexes containing closo- or nido-carborane diphosphine ligands with the formula: complex $[Hg(7,8-(PPh_2)_2-7,8-C_2B_9H_{10})_2]$ $CH_2Cl_2$ (1) and $[Ag_2({\mu}-Cl)_2(1,2-(P^iPr_2)_2-1,2-C_2B_{10}H_{10})_2]$ (2) have been synthesized and characterized by elemental analysis, 1H and 13C NMR spectroscopy and X-ray structure determination. The X-ray structure analyses revealed that the carborane diphosphine ligand was degraded from closo-1,2-$(PPh_2)_2-1,2-C_2B_{10}H_{10}$ to nido-[$7,8-(PPh_2)_2-7,8-C_2B_9H_{10}]^-$ in complex 1, while the closo nature of the starting ligand $1,2-(P^iPr_2)_2-1,2-C_2B_{10}H_{10}$ was retained in complex 2. In either of the two complexes, the carborane diphosphine ligand was coordinated bidentately to the Hg(II) or Ag(I) center through its two phosphorus atoms, therefore forming a five-member cheating ring between the carborane ligand and the metal center. The coordination geometry of the metal atom is distorted tetrahedron formed by $P_4$ unit in complex 1 and $P_2Cl_2$ unit in complex 2, respectively.

• 한국식품영양학회지
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• 제23권1호
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• pp.63-69
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• 2010

다제내성균 A. baumannii에 유용한 항생물질을 생산하는 방선균을 선별하기 위하여 토양에서 분리한 방선균 300여 균주를 대상으로 항균 활성을 실험하여 그 활성이 가장 뛰어난 B-51 균주를 최종적으로 선별하였다. 이 균으로부터 항생물질 생산을 위한 최적 조건을 조사하기 위하여 발효 배지를 기본배지로 하여 동일조건 하에서 탄소원, 질소원, 무기염 및 인삼염만을 다르게 하여 항균 활성을 실험한 결과 glycerol 2%, soybean meal 0.5%, $CaCl_2$ 0.01%, $MgSO_4{\cdot}7H_2O$ 0.01%, $KH_2PO_4$ 0.01%에서 항생물질 생산이 가장 높았다. 또한 이렇게 결정된 배지 조성에서 초기 pH 6.0, 배양온도 $30^{\circ}C$, 배양시간 76시간 조건 하에서 항생물질 생산이 가장 많았다. 항생물질을 생산하는 대부분의 방선균이 항생물질 생산 시 배양액의 final pH가 중성 혹은 약 알칼리인 점을 비교해 볼 때 본 균주인 B-51의 경우 항생물질 생산능이 높은 경우 final pH 4.0 부근인 산성 pH를 보여 그간의 논문보고와는 상반되는 결과를 보였다.

• Asian-Australasian Journal of Animal Sciences
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• 제14권12호
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• pp.1670-1674
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• 2001

To understand molecular mechanisms that regulate deposition and release of intramuscular fat, a fasting-induced clone was identified by differential screening from cDNA library of adipose tissues of Korean cattle. The clone had a total length of 1,319 nucleotides coding for 334 amino acids. It was identified as one encoding L-lactate dehydrogenase H chain (LDH-B). Comparison of the deduced amino acid sequences of bovine LDH-B with those of pig, human, rat, and mouse showed 98%, 98%, 97%, and 96% identity, respectively. Food deprivation for 48 h increased mRNA levels of LDH-B gene in adipose tissues of Korean cattle compared to fed- and 6 h refed- tissues. The expression of obese mRNA was examined for individual adipose tissue from several fat depots. Fasting induced expression of LDH-B gene in subcutaneous adipose tissues, but it did not affect expression levels in abdominal, perirenal and intramuscular tissues. Results demonstrate that induction of LDH-B gene during fasting may represent a metabolic shift from anaerobic state to aerobic predominance in fasted adipose tissues and that its responses to fasting are different among several adipose tissues.

• 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>$R_{b2}$./.