• Macromolecular Research
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• 제17권12호
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• pp.1032-1038
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• 2009

A polypyrrole (PPy)/alumina composite filler prepared via in-situ polymerization of pyrrole on alumina particles was incorporated into $Nafion^{(R)}$ to improve the performance of ionic polymer-metal composite (IPMC) actuators. The IPMCs with the pristine PPy without alumina support did not show bending displacements superior to that of the bare Nafion-based IPMC, except at a high PPy content of 4 wt%. This result was attributed to the low redox efficiency of the PPy alone in the IPMC and may have also been related to the modulus of the IPMC. However, at the optimized filler contents, the cyclic displacement of the IPMCs bearing the PPy/alumina filler was 2.2 times larger than that of the bare Nafion-based IPMC under an applied AC potential of 3 Vat 1 Hz. Even under a low AC potential of 1.5 V at 1 Hz, the displacement of the PPy/alumina-based IPMCs was a viable level of performance for actuator applications and was 2.7 times higher than that of the conventional Nafion-based IPMC. The generated blocking force was also improved with the PPy/aiumina composite filler. The greatly enhanced performance and the low-voltage-operational characteristic of the IPMCs bearing the PPy/alumina filler were attributed to the synergic effects of the neighboring alumina moiety near the PPy moiety involving electrochemical redox reactions.

• BMB Reports
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• 제48권8호
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• pp.461-466
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• 2015

Epigallocatechin gallate (EGCG) and curcumin are well known to naturally-occurring anticancer agents. The aim of this study was to verify the combined beneficial anticancer effects of curcumin and EGCG on PC3 prostate cancer cells, which are resistant to chemotherapy drugs and apoptosis inducers. EGCG showed weaker inhibitory effect on PC3 cell proliferation than two other prostate cancer cell lines, LNCaP and DU145. Co-treatment of curcumin improved antiproliferative effect of EGCG on PC3 cells. The protein expressions of p21 were significantly increased by the co-treatment of EGCG and curcumin, whereas it was not changed by the treatment with each individual compound. Moreover, treatments of EGCG and curcumin arrested both S and G2/M phases of PC3 cells. These results suggest that the enhanced inhibitory effect of EGCG on PC3 cell proliferation by curcumin was mediated by the synergic up-regulation of p21-induced growth arrest and followed cell growth arrest. [BMB Reports 2015; 48(8): 461-466]

• 한국연초학회지
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• 제20권1호
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• pp.99-107
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• 1998

Numerous studies have demonstrated a negative association between cigarette smoking and Parkinson's disease. The present study was undertaken to investigate whether chronic exposure of mice to cigarette smoke a(footed the metabolism of 1-methyl-1113,6-tetrahydro-pyridine (MPTP) by cytochrome P4SO (P-450) or flavin-containing monooxygenase (FMO) in the hepatic microsomes of C57BL6/J mice. Adult male C57BL6/J mice were exposed to mainstream smoke generated from 15 cigarettes for 10 min a day and 5 day per week for 6 weeks. MPTP (10 mg/kg body weight) was administered to mice by subcutaneous injection for 6 consecutive days. Microsolnal P-450 content was increased by MPTP, smoke exposure, or both, but NADPH cytochrome P-450 reductase activity was rather decreased by the same treatments. The activities of benzo(a)pyrene hydroxylase, 7-ethoxycoumarin O-deethylase and ethoxyresorufin O-deethylase were significantly increased by the exposure of cigarette smoke, but were not or little affected by MPTP treatment. Benzphetamine N-demethylase activity was not affected either by MPTP treatment or by cigarette smoke exposure, but it was significantly increased by the combined MPTP treatment with cigarette smoke exposure, showing their synergic effect for the induction of the enzyme activity. Interestingly, in vitro studies of hepatic FMO and P-450 system both O-oxygenation and N-demethylation of MPTP were increased in the smoke-exposed or in the MPTP-treated mice. These results suggest that the enhancement in the N-demethylation as well as O-deethylation of P-450 system and in the N-oxygenation of FMO activity by cigarette smoke exposure in mouse liver may contribute to attenuating the neurotoxic effects of MPTP on the nigrostriatal dopaminergic neurons.

• 대한한의학방제학회지
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• 제17권2호
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• pp.85-98
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• 2009

The fruits of Schisandra chinensis and Prunus mume have been traditionally used in the Oriental countries as an astringent against diarrhea and abdominal pain, a protectant for liver disease, an antimicrobial, and a blood tonic. However, little is known about the extract of Schizandrae Fructus and Mume Fructus (SMF-Ex) on dextran-sulfate sodium (DSS)-induced colitis in mice. In this study, we investigated the protective effects of SMF-Ex on DSS-induced colitis in mice. An experimental colitis was induced by daily treatment with 5% DSS. SMF-Ex was orally administrated the single dose (80 mg/kg, body weight/day) for 7 days with one time per day. SMF-Ex reduced significantly clinical sign of DSS-induced colitis, including body weight loss, shorten colon length, increased disease activity index (DAI), and histological colon injury. SMF-Ex also inhibited significantly nitric oxide (NO) and prostaglandine $E_2$ ($PGE_2$) productions in DSS-induced colitis mice. Furthermore, SMF-Ex increased significantly an superoxide anion (SOD), catalase, and glutathione peroxidase (Gpx) activity of the colon tissue in DSS-induced colitis mice. These results suggest that SMF-Ex administration could reduce significantly the clinical signs and inflammatory mediators, and increase antioxidant activity in DSS-induced colitis model mice and is a good candidate for further evaluation as an effective anti-ulcerative agent.

• Asian-Australasian Journal of Animal Sciences
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• 제17권3호
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• pp.374-378
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• 2004

One hundred and twenty crossbred pigs [(Duroc$\times$Yorkshire)$\times$Landrace] were used to determine the effects of plant extract (PE) supplementation on performance and blood characteristics in weaned pigs fed a corn-dried whey-SBM based diet. Treatments were 1) NC (antibiotic free basal diet), 2) PC (NC diet+100 ppm apramycin and 100 ppm oxytetracycline), 3) PE 0.1 (NC diet+0.1% plant extract), 4) PE 0.2 (NC diet+0.2% plant extract) and 5) PE+AB (PC diet+0.1% plant extract). Through the entire experimental period, ADG of pigs fed PC (300 vs. 281 g/d), PE 0.2 (310 vs. 281 g/d) and PE+AB (306 vs. 281 g/d) diets was higher than that of pigs fed NC diet (p<0.05). However, no differences were found among the treatments for ADFI and gain/feed. At day 2 after the onset of the experiment, fecal consistency score of pigs fed PC, PE 0.1, PE 0.2 and PE+AB diets was lower than that of pigs fed NC diet. There were no significant differences in red blood cell, white blood cell, lymphocytes, neutrophils and monocytes concentrations of blood among the treatments. In conclusion, PE can be used to replace antibiotics in diets for weaned pigs without negative affects on performance. Optimal PE levels seemed to be 0.2% and the results obtained point out to a synergic effect of the combination of PE and antibiotic on performance in weaned pigs.

• 한국미생물·생명공학회지
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• 제43권1호
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• pp.16-21
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• 2015

2세대 바이오매스 볏짚을 이용하여 전자선 조사 후 NMMO 처리 공정을 수행하고 이를 분석하였다. 볏짚은 전자선 500 kGy 조사 후 NMMO 처리를 한 경우 72시간의 효소당화를 거쳐 글루코스 60.8%와 자일로스 9.7% 포함 약 83.8% 정도의 당수율을 보였다. 이 전처리 공정은 유해한 화학물질을 사용하지 않아서 친환경적이며 전자선 조사와 NMMO 처리의 시너지 효과가 있음을 알 수 있었다. 그러나 전자선 조사량이 너무 높다는 단점이 있으며 추후에는 낮은 전자선 조사량과 여러 가지 단일공정을 통합한 새로운 복합전처리 방법 연구의 필요성이 있다. 따라서 이 단점을 보완한다면 전자선 조사라는 친환경적 방법과 더불어 NMMO 용액의 재활용성을 이유로 바이오에탄올 생산 등의 산업현장에의 적용 가능성이 높다는 것을 알 수 있었다.

• 분석과학
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• 제23권5호
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• pp.429-436
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• 2010

본 연구는 다양한 종류의 음이온 교환수지와 활성탄으로 구성된 새로운 혼합 수지를 과염소산 이온의 제거에 응용할 경우, 각 흡착제들이 갖는 장점으로 인한 시너지 효과를 얻을 수 있는지 조사하였다. 특히 비군사화 과정에서 발생하는 고 농도의 과염소산 암모늄용액을 대상으로 하였는데, 혼합수지 중단일-기능기 음이온 교환수지와 활성탄의 조합에서 과염소산 이온의 흡착 효율이 향상되었다. 일반적으로는 분리된 흡착조를 이용하여 유기 오염물과 무기 음이온의 제거가 시행되는데 반해, 본 연구에서 시도한 혼합 수지를 사용할 경우 한 번에 동시 제거가 가능하여 제거과정에서 필요한 시간, 공간 및 비용을 감소시키는 효과를 얻을 수 있었다. 또한, 시료 중의 공존 음이온들에 대한 방해효과도 낮고 음이온 교환 수지에 비하여 특별한 단점이 없으며 실제시료에도 효과적으로 응용이 가능하였다.

• Molecules and Cells
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• 제39권2호
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• pp.129-135
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• 2016

Eukaryotic translation initiation factor 2 alpha ($eIF2{\alpha}$), which is a component of the eukaryotic translation initiation complex, functions in cell death and survival under various stress conditions. In this study, we investigated the roles of $eIF2{\alpha}$ phosphorylation in cell death using the breast cancer cell lines MCF-7 and MCF-7/ADR. MCF-7/ADR cells are MCF-7-driven cells that have acquired resistance to doxorubicin (ADR). Treatment of doxorubicin reduced the viability and induced apoptosis in both cell lines, although susceptibility to the drug was very different. Treatment with doxorubicin induced phosphorylation of $eIF2{\alpha}$ in MCF-7 cells but not in MCF-7/ADR cells. Basal expression levels of Growth Arrest and DNA Damage 34 (GADD34), a regulator of $eIF2{\alpha}$, were higher in MCF-7/ADR cells compared to MCF-7 cells. Indeed, treatment with salubrinal, an inhibitor of GADD34, resulted in the upregulation of $eIF2{\alpha}$ phosphorylation and enhanced doxorubicin-mediated apoptosis in MCF-7/ADR cells. However, MCF-7 cells did not show such synergic effects. These results suggest that dephosphorylation of $eIF2{\alpha}$ by GADD34 plays an important role in doxorubicin resistance in MCF-7/ADR cells.

• 동의생리병리학회지
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• 제19권3호
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• pp.753-759
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• 2005

In order to evaluate the in vivo synergic effect of Eunkyo-san with quinolone antibiotics, rufloxacin (RUFX), the viable bacterial numbers and histopathological changes were monitored after experimental respiratory infection with Klebsiella peumoniae NCTC 9632. The obtained results were as follows : In RUFX group, the viable bacterial numbers were significantly decreased compared to those of control group and these were more dramatically decreased compared to those of single treatment with RUFX, respectively in concomitant treated groups with Eunkyo-san. In control group, severe infiltration of inflammatory cells, hemorrhage and hypertrophy of alveolar linings were demonstrated at microscopical levels. However, these abnormal histopathological changes were significantly decreased compared to those of control group in RUFX group, and these were more dramatically decreased compared to those of single treatment with RUFX, respectively in concomitant treated groups with Eunkyo-san. In RUFX group, the LSA% (luminal surface of alveolar%) were significantly increased compared to those of control group and these were more dramatically decreased compared to those of single treatment with RUFX, respectively in concomitant treated groups with Eunkyo-san. According to these results, it is considered that in vivo antibacterial activity of RUFX group was dramatically increased by concomitant use of Eunkyo-san against K. pneumoniae NCTC 9632 infection of respiratory tract.

• 디지털융복합연구
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• 제15권1호
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• pp.163-170
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• 2017

본 연구는 기업가정신, 동적역량, 혁신활동 각각의 변수와 그 변수들 간의 적합성이 기업의 경영성과에 미치는 영향을 살펴보는 데 목적이 있다. 중소기업을 대상으로 설문조사를 실시한 후 상관관계분석과 다중회귀분석을 적용하여 적합성을 확인하고 이 적합성이 경영성과에 유의적인 영향을 미치는가를 실증 분석하였다. 연구결과는 다음과 같다. 첫째, 기업가정신과 동적역량, 기업가정신과 혁신활동, 동적역량과 혁신활동 등 두 변수 간의 적합성은 경영성과에 유의적인 영향을 미치는 것으로 나타났다. 둘째, 기업가정신, 동적역량, 혁신활동 세 변수 모두의 적합성도 경영성과에 유의한 정(+)의 영향을 미쳤다. 추가로 실시한 경로분석에서는 기업가정신과 경영성과와의 관계에서 동적역량과 혁신활동의 매개효과를 발견할 수 있었다. 본 연구의 결과, 기업가정신과 동적역량, 혁신활동은 각각 경영성과에 기여할 뿐만 아니라 이들 세 요인들을 조화롭게 구현함으로써 기업의 경영성과를 더욱 향상시킬 수 있음을 실증하였다.