• Journal of Microbiology and Biotechnology
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• 제11권5호
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• pp.772-775
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• 2001

A highly $CO_2$ tolerant microalga, Chlorella KR-1, has been isolated and used to fix $CO_2$ from actual flue gas. Growth of Chlorella KR-1 with the supply of flue gas from a liquified natural gas boiler was comparable to that obtained with 10% $CO_2$. Chlorella KR-1 produced from $CO_2$ fixation using the flue has about 50% crude protein with balanced amino acid profiles. Toxicity was not detected when the microalga was used as a feedstuff for chicks. These results indicate that the KR-1 cells could be a favorable protein source for poultry.

• 한국임상약학회지
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• 제6권2호
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• pp.32-40
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• 1996

The electrophysiological effects of benzopyran potassium channel openers (PCOs: lemakalim, KR-30450 and KR-30818) on the ischemia/reperfusion-induced arrythmias were investigated. In anesthetized rats, subjected to 45 min occlusion of the left anterior descending coronary artery (LAD) followed by 90 min reperfusion, ventricular arrythmias were identified according to the Lambeth Conventions by lead II ECG. Rats were intravenously given vehicle ($1\%$ DMSO), lemakalim, KR-30450, and KR-30818 alone or in combination with a selective $K_{ATP}$ blocker glibenclamide, 30 min prior to coronary occlusion. Compared to vehicle, lemakalim ($30{\mu}g/kg$ i.v.), the active enantiomer of cromakalim, had a tendancy to increase the duration of ventricular tachycardia (Vl) and ventricular fibrillation (VF), the number of premature ventricular complexes (PVC) and the incidence of VF, especially in the early post-occlusion peroid ($0\~15$ min), while increasing ST-segment elevation. Both KR-30450 ($30{\mu}g/kg$, i.v.) and KR-30818 (30, $100{\mu}g/kg$, i.v.) showed similar proarrhythmic effects to lemakalim (PVC, duration of VT, and incidence of VF) with a tendancy to decrease the duration of VF and ST-segment elevation. Unlike other PCOs, however, glibenclamide (0.3, 1.0 mg/kg) had opposite effects on the induction of arrhythmias (PVC, the duration of VF); it had a tendancy to increase the duration of VT with a slight elevation of ST-segment. It seems likely that glibenclamide (0.3 mg/kg, i.v.), reduced the effects of lemakalim or KR-30450 ($30{\mu}g/kg$, i.v.) on arrhythmias (PVC, VT, VF and ST-segment). These results indicate that, in the coronary occluded rat model of ischemia, lemikuiln and KR-30450 exert a proarrhythmic activity, the effect being considered related to the opening of KATP channel.

• Archives of Pharmacal Research
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• 제27권2호
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• pp.239-245
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• 2004

KR-31543, (2S,3R,4S)-6-amino-4-[N-(4-chlorophenyl)-N-(2 -methyl-2H-tetrazol-5-ylmethyl) amino]-3,4-dihydro-2-dimethoxymethyl-3-hydroxy-2-methyl-2H-1-benzopyran, is a new neuroprotective agent for preventing ischemia-reperfusion damage. This study was performed to identify the metabolic pathway of KR-31543 in human liver microsomes and to characterize cytochrome P450 (CYP) enzymes that are involved in the metabolism of KR-31543. Human liver microsomal incubation of KR-31543 in the presence of NADPH resulted in the formation of two metabolites, M1 and M2. M1 was identified as N-(4-chlorophenyl)-N-(2-methyl-2H-tetrazol-5-ylmethyl)amine on the basis of LC/MS/MS analysis with a synthesized authentic standard, and M2 was suggested to be hydroxy-KR-31543. Correlation analysis between the known CYP enzyme activities and the rates of the formation of M 1 and M2 in the 12 human liver microsomes have showed significant correlations with testosterone 6$\beta$-hydroxylase activity (a marker of CYP3A4). Ketoconazole, a selective inhibitor of CYP3A4, and anti-CYP3A4 monoclonal antibodies potently inhibited both N-hydrolysis and hydroxylation of KR-31543 in human liver microsomes. These results provide evidence that CYP3A4 is the major isozyme responsible for the metabolism of KR-31543 to M1 and M2.

• The Plant Pathology Journal
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• 제24권3호
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• pp.361-364
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• 2008

The complete nucleotide sequences of a Korean isolate of Potato virus X(PVX-Kr) has been determined. Full-length cDNA of PVX-Kr has been directly amplified by long template reverse transcription and polymerase chain reaction(RT-PCR) using virus specific 5'-end primer and 3'-end primer, and then constructed in a plasmid vector. Consecutive subclones of a full-length cDNA clone were constructed to identify whole genome sequence of the virus. Total nucleotide sequences of genome of PVX-Kr were 6,435 excluding one adenine at poly A tail, and genome organization was identical with that of typical PVX species. Comparison of whole genome sequence of PVX-Kr with those of European and South American isolates showed 95.4-96.8% and 77.4-77.9%, in nucleotide similarity, respectively. Sequenced PVX-Kr in this study and twelve isolates already reported could be divided into two subgroups in phylogeny based on their complete nucleotide sequences. Phylogenetic tree analysis demonstrated that PVX-Kr was clustered with European and Asian isolates(Taiwan, os, bs, Kr, S, X3, UK3, ROTH1, Tula) in the same subgroup and South American isolates(CP, CP2, CP4, HB) were clustered in the other subgroup.

• Archives of Pharmacal Research
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• 제26권10호
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• pp.800-804
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• 2003

The effects of KR-31378, a neuroprotective agent for ischemia-reperfusion damage, on liver microsomal cytochrome P450s (CYPs) were investigated in male Sprague Dawley rats. When rats were treated orally with KR-31378 for 7 consecutive days, CYP3A-selective erythromycin N-demethylase (ERDM) activity was significantly induced in a dose-dependent manner. In Western immunoblotting, CYP 3A proteins were clearly induced by treatment with KR-31378. Within 24 h after treatment with 80 mg/kg of KR-31378, ERDM activity was induced in liver microsomes in accompanied by induction of the level of CYP 3A proteins. The present results suggest that KR-31378 might modulate the expression of CYP 3A enzymes in humans.

• 조명전기설비학회논문지
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• 제22권8호
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• pp.104-108
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• 2008

플라즈마 현상의 정량적 이해를 위해서는 원자나 분자기체가 가지고 있는 정확한 전자충돌단면적과 그 전자수송 계수의 값을 필요로 한다. 본 연구에서 사용하고 있는 Kr과 Xe 원자기체는 PDP와 무전각램프 등 다양한 산업 응용분야에 이용되고 있다. 따라서 2항 근사 볼츠만 해석에 의해 기체압력 1[torr]의 조건에 $0.001{\sim}500$[Td]의 광범위한 E/N에서 순수 Kr과 Xe 원자기체의 전자이동속도 W, 종 횡축확산계수 $ND_L$과 $ND_T$, 전리계수 $\alpha$/N의 전자수송 계수를 계산하고 물성 해석하였다.

• 생명과학회지
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• 제20권6호
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• pp.831-837
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• 2010

KR-31125는 피리딜 이미다졸 시리즈 화합물로서 비펩타이드 안지오텐신 수용체 길항제로 새롭게 개발되었다. 동위원소 리간드를 사용한 재조합 수용체 결합실험과 기능성 토끼혈관실험 결과 기존 의약인 로자탄과 동등수준의 수용체 길항효과를 나타내었다. 이러한 KR-31125의 특징들은 제 1형 안지오텐신 수용체에 특이적으로 나타났으며($IC_{50}$: $19.72{\pm}2.65\;nM$), 표준물질에 대한 대조실험 결과 제 2형 안지오텐신 수용체에 대한 결합친화력은 발견되지 않았다. 기능성 혈관실험에서 KR-31125가 안지오텐신에 의한 혈관수축 효과를 경쟁적으로 저하시켰지만 표준물질인 로자탄과는 달리 농도가 증가함에 따라 30-80% 정도의 최대 수축효과 감소가 관찰되어 로자탄과는 다른 분자작용 기전을 가진다고 판단된다. 제 1형 안지오텐신 수용체에 선택적으로 작용하는 것으로 나타난 KR-31125는 레닌-안지오텐신-알도스테론 시스템에 대한 연구 및 진단에 폭 넓게 활용될 수 있는 표지자 화합물로 가능성을 넓혀 줄 수 있을 것이라고 판단된다.

• Archives of Pharmacal Research
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• 제28권11호
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• pp.1287-1292
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• 2005

KR-33028 (N-[4-cyano-benzo[b]thiophene-2-carbonyl]guanidine) is a new cardioprotective agent for preventing ischemia-reperfusion injury. This study was performed to identify the metabolic pathway of KR-33028 in human liver microsomes and to compare its metabolism with that of cryopreserved human hepatocytes. Human liver microsomal incubation of KR-33028 in the presence of NADPH and UDPGA resulted in the formation of four metabolites, M1, M2, M3, and M4. M1 and M2 were identified as 5-hydroxy-KR-33028 and 7-hydroxy-KR-33028, respectively, on the basis of LC/MS/MS analysis with the synthesized authentic standard. M3 and M4 were suggested to be dihydroxy-KR-33028 and hydroxy-KR-33028-glucuronide, respectively. Metabolism of KR-33028 in cryopreserved human hepatocytes resulted in the formation of M1, M2, and M4. These data show a good correlation between major metabolites formed in human liver microsomes and cryopreserved human hepatocytes. In addition, KR­33028 was found to inhibit moderately the metabolism of CYP1A2 substrates. Based on the results obtained metabolic pathway of KR-33028 is proposed.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제50권12호
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• pp.599-606
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• 2001

In this paper, the ac breakdown characteristics of pure Ar, Kr and $N_2$ gas with gas pressure range of 58.8-137.3[kPa] under uniform and non-uniform fields were investigated, and the measured values were compared with those In Ar/$N_2$ and Kr/$N_2$ gas mixtures with pressure varying. Summarizing the experimental results, the breakdown voltages of Pure $N_2$gas, under uniform and non-uniform fields, were increased about 4.8 and 1.1 times than those of pure Ar gas, and about 4.4 and 1.2 times than those of pure Kr gas, and the ac breakdown voltage increased with the pressure increasing. The breakdown voltages of Ar/$N_2$ gas mixtures were decreased with decreasing the mixture ratio of Pure $N_2$ gas. In case of Ar(85%)/$N_2$ (15%) and Ar(70%)/$N_2$ (30%) gas mixtures comparing to the pure Ar gas, the breakdown voltages under uniform field were increased about 1.8 and 2.2 times, and under non-uniform field were increased about 1.1 and 1.3 times at the pressure of 101.3[kPa]. Also, in case of Kr(85%)/$N_2$ (15%) and Kr(70%)/$N_2$ (30%) gas mixtures comparing to the pure Kr gas, the breakdown voltages under uniform field were increased about 1.7 and 2.0 times, and under non-uniform field were increased about 1.0 and 1.2 times. Corona inception voltage of Kr(70%)/$N_2$(30%) gas mixtures under non-uniform fields were increased about 1.28 times than those of Ar(70%)/$N_2$ (30%) gas mixtures. In case of practical incandescent lamps, luminous and lifetime of Kr(70%)/$N_2$ (30%) gas mixtures were increased about 1.15 and 1.21 times than those of Ar(70%)/$N_2$ (30%) gas mixtures.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1989년도 추계학술대회 논문집 학회본부
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• pp.505-508
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• 1989

A computer simulation code of UV preionized discharge KrF laser is developed, including time dependent circuit equations, boltzmann equations, and plasma kinetic equations for various atomic and molecular species. Rate constants for electron collision processes are calculated with a boltzmann equations as a function of E/N. In this study, we studied mainly the $KrF^*$ formation process, relaxation process, and the 248nm absorption process as a function of charging voltage.