• 한국미생물·생명공학회지
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• 제29권3호
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• pp.181-185
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• 2001

유방암 세포주에서는 우수한 항암활성을 가진 것으로 알려진 indole-3-carbinol을 HepG2세포주에 시간과 농도별로 처리한 결과 cell growth inhibition을 확인하였으며, $IC_{50}$ 값은 48시간배양에서 $446\mu$M 72시간 배양에서 444$\mu$M로 나타났다. $400\mu$M의 I3C을 투여하고, 24, 48, 72시간에 HePG2 세포주의 cell cycle pattern을 분석한 결과, G1 phase에서 P21의증가와 함께 Cdk 6와 cyclin D의 확연한 감소와 Pb protein의 hypo-phosphorylation을 확인하였다. 반면 G2 phase에서는 I3C의 직접적인 억제로 인해 24시간 후부터 Cdc2와 cyclin B1가 급격히 감소하는것을 확인하였다. Flow cytomery 분석결과 I3C 처리 24시간 뒤 G2 arrest (25%)가 발생하였으며, 72시간이 지난후 G1 arrest (53%)가 발생하였다. 이러한 I3C의 간암세포주인 HePG2 cell의 cell cycle arrest가 apoptosis를 유발하는지를 알고자 caspase 3 Bcl2 Bax protein의 발현양상을 확인한 결과 아무런 변화가 보이지 않았다. 즉 I3C은 간암세포주인 HepG2 cell에서 apoptosis를 유도하지 못한다는것을 확인하였따. 결론적으로 I3C은 HepG2 세포주에서 G1와 G2 phase에서 cell cycle arrest는 발생시키나, 특이적으로 apoptosis 와는 연관되지 않는다는 사실을 확인하였다.

• Archives of Pharmacal Research
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• 제23권4호
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• pp.349-352
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• 2000

A reversed-phase high performance liquid chromatographic method was developed to determine salidroside and tyrosol simultaneously in the Rhodiola rosea. The optimum condition was Nova-pak $C_18$as stationary phase, 6.5% methanol in water as mobile phase and detection at UV 225 nm. The identification was carried out by comparing the retention time and LC/MS spectrum of the relevant peaks with those of isolated standards. The contents of salidroside and tyrosol in the samples gathered from various area in China were ranged over 1.3-11.1 ${m}g/g$ and 0.3-2.2 ${m}g/g$, respectively.

• 분석과학
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• 제18권3호
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• pp.224-231
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• 2005

잔류농약 분석에 전통적으로 사용되는 액체-액체 추출법과 액체-고체 추출법의 여러 가지 단점을 극복하고 기존의 낮은 정밀도와 저조한 추출효과를 보완하기위해 자동화된 장치를 이용한 액체상 극미량 추출법(Liquid Phase Microextraction : LPME)을 사용하였으며 이에 대한 최적화 조건을 설정하였다. 대상농약은 demeton-S-methyl, diazinon, parathion, fenitrothion, EPN등 5종이었으며 채소 시료 중에서 추출하여 HP 6890 GC/NPD를 사용하여 분석하였다. 자동화된 LPME를 이용한 최적의 추출조건은 pH 3, 염의 농도 $100{\mu}g/mL$이었으며 검량선을 작성하였을 때 $0.2{\sim}10{\mu}g/g$ 범위에서 $R^2=0.9921$ 이상 직선상의 상관관계를 나타내었고 $5{\mu}g/g$ 농도에서 demeton-S-methyl은 7.7%, diazinon은 9.8%, parathion은 7.8%, fenitrothion는 9.7%, EPN은 8.2%의 상대표준편차를 나타내었고 정확도는 demeton-S-methyl는 12.7%, diazinon는 7.8%, parathion는 10.4%, fenitrothion는 -6.7%, EPN은 -0.7%로 좋은 값을 나타내었다.

• 전기화학회지
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• 제15권1호
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• pp.54-66
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• 2012

The phase-shift method and correlation constants, which are unique electrochemical impedance spectroscopy techniques for studying the linear relationship between the phase shift ($90^{\circ}{\geq}-{\varphi}{\geq}0^{\circ}$) vs. potential (E) behavior for the optimum intermediate frequency ($f_o$) and the fractional surface coverage ($0{\leq}{\theta}{\leq}1$) vs. E behavior, are proposed and verified to determine the Frumkin, Langmuir, and Temkin adsorption isotherms and the related electrode kinetic and thermodynamic parameters. At Ni/0.5 M $H_2SO_4$ and 0.1M LiOH aqueous solution interfaces, the Frumkin and Temkin adsorption isotherms (${\theta}$ vs. E) of H for the cathodic hydrogen ($H_2$) evolution, interaction parameters (g), equilibrium constants (K), standard Gibbs energies (${\Delta}G^0_{\theta}$) of H adsorption, and rates of change (r) of ${\Delta}G^0_{\theta}$ with ${\theta}$ have been determined using the phase-shift method and correlation constants. A lateral repulsive interaction (g>0) between the adsorbed H species appears. The value of K in the alkaline aqueous solution is much greater than that in the acidic aqueous solution.

• Bulletin of the Korean Chemical Society
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• 제33권3호
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• pp.917-924
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• 2012

The conformational study of glycerol has been carried out using the M06-2X/cc-pVTZ level of theory in the gas phase and the SMD M06-2X/cc-pVTZ level of theory in water in order to understand its conformational preferences and solvation effects. Most of the preferred conformers of glycerol have two $C_5$ hydrogen bonds in the gas phase, as found by the analysis of calorimetric data. It has been known that the solvation drove the hydrogen bonds of glycerol to be weaker and its potential surface to be fatter and that glycerol exists as an ensemble of many feasible local minima in water. The calculated populations of glycerol in the gas phase and in water are consistent with the observed values, which are better than the previously calculated ones at the G2(MP2), CBS-QB3, and SM5.42 HF/6-31G(d) levels of theory.

• 생명과학회지
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• 제17권12호
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• pp.1634-1640
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• 2007

음나무 (Kalopanax pictus, 이하 KP)의 추출물과 ascorbic acid(AA)의 DPPH와 ABTS 라디칼, FRAP 및 NO 소거능 상승효과를 조사하였다. 라디칼 소거능과 항산화능은 농도에 비례하여 증가하였으며, AA 첨가에 의해서 그 활성이 향상되었다. 인간 간암세포주에 대한 KP추출물+AA의 항암능은 MTT법에서 우수한 효과를 나타내었으며 세포 사멸을 유도하였다. 또한 KP 추출물+AA는 세포주기의 G0/G1-phase 또는 G2/M-phase에 영향을 미쳤으며, 농도 의존적인 효과를 나타내었다. 그리고 KP추출물+AA는 대식세포주를 이용한 NO생성과 억제의 면역활성 영향을 나타내었다. 결론적으로 KP추출물의 항산화, 항암 및 면역조절 효과는 KP추출물 단독으로 처리할 때보다, KP 추출물과 AA를 동시에 처리한 경우가 더욱 효과적이었다.

• 한국연초학회지
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• 제28권2호
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• pp.152-157
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• 2006

A new procedure has been developed for the quantitation of aromatic amines in mainstream cigarette smoke. Two solid-phase extraction (SPE) clean up steps, using a different retention mechanisms, are required to process the samples. The first step used a cation-exchange cartridge, followed by a second step that used a cartridge with a hydrophobic retention character. The aromatic amines eluted from the second SPE cartridge are derivatized with pentafluoropropionic anhydride. This new method have advantages over other reported techniques, being sensitive, robust, and easily automated. The detection limits were ranged from 0.12 ng/mL for 1-aminonaphthalene to 0.16 ng/mL for 3-aminobiphenyl and the recoveries were from 97 to 106%. Compared with other reports for analysis of 2R4F reference cigarette, this method shows a close analytical data and good repeatability.

• BMB Reports
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• 제44권8호
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• pp.529-534
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• 2011

Ribosomal protein S3 (rpS3) is a multifunctional protein involved in translation, DNA repair, and apoptosis. The relationship between rpS3 and cyclin-dependent kinases (Cdks) involved in cell cycle regulation is not yet known. Here, we show that rpS3 is phosphorylated by Cdk1 in G2/M phase. Co-immunoprecipitation and GST pull-down assays revealed that Cdk1 interacted with rpS3. An in vitro kinase assay showed that Cdk1 phosphorylated rpS3 protein. Phosphorylation of rpS3 increased in nocodazole-arrested mitotic cells; however, treatment with Cdk1 inhibitor or Cdk1 siRNA significantly attenuated this phosphorylation event. The phosphorylation of a mutant form of rpS3, T221A, was significantly reduced compared with wild-type rpS3. Decreased phosphorylation and nuclear accumulation of T221A was much more pronounced in G2/M phase. These results suggest that the phosphorylation of rpS3 by Cdk1 occurs at Thr221 during G2/M phase and, moreover, that this event is important for nuclear accumulation of rpS3.

• 한국재료학회지
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• 제6권11호
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• pp.1099-1106
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• 1996

니켈-수소화물전지의 음극재료로서 주목을 받고 있는 다원계 Zr기 Laves 합금의 조성에 따른 결정구조, 방전특성등을 조사하였다. 전극은 아크 용해한 합금을 분쇄한 분말과 PVA를 다공성니켈 foam에 충진하여 제작하였고 충방전시험은 6M KOH 용액중에서 수행하였다. 대상 합금은 ZrNi2를 기본조성으로 하여 이중 Ni의 일부를 V, Mn, Cr, Mo 또는 W로 치환한 삼원계 및 사원계 합금이었다. 이들 합금의 충방전 실험결과 ZrV0.5Mn0.5Ni1.0의 경우가 260 mAh/g로 가장 높은 방전용량을 나타내었다. 이 합금의 방전용량은 방전전류밀도의 영향을 크게 받았으며 10 mA/g과 200mA/g의 방전전류에서 각각 300mAh/g와 150mAh/g이었다. 이 합금을 110$0^{\circ}C$에서 열처리한 경우 저율방전시에는 방전용량의 변화가 거의 없었으나 수소의 확산이 율속이 될 것으로 생각되는 고율 방잔시에서는 방전용량이 현저하게 감소하였다. 이러한 현상은 열처리에 의해 수소의확산을 용이하게 해주는 격자결함이 감소하기 때문이 아닌가 생각된다.

• Asian Pacific Journal of Cancer Prevention
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• 제16권18호
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• pp.8313-8319
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• 2016

We have recently shown that thymoquinone (TQ) has a potent cytotoxic effect and induces apoptosis via caspase-3 activation with down-regulation of XIAP in mouse neuroblastoma (Neuro-2a) cells. Interestingly, our results showed that TQ was significantly more cytotoxic towards Neuro-2a cells when compared with primary normal neuronal cells. In this study, the effects of TQ on cell-cycle regulation and the mechanisms that contribute to this effect were investigated using Neuro-2a cells. Cell-cycle analysis performed by flow cytometry revealed cell-cycle arrest at G2/M phase and a significant increase in the accumulation of TQ-treated cells at sub-G1 phase, indicating induction of apoptosis by the compound. Moreover, TQ increased the expression of p53, p21 mRNA and protein levels, whereas it decreased the protein expression of PCNA, cyclin B1 and Cdc2 in a dose-dependent manner. Our finding suggests that TQ could suppress cell growth and cell survival via arresting the cell-cycle in the G2/M phase and inducing apoptosis of neuroblastoma cells.