• 전기화학회지
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• 제23권1호
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• pp.11-17
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• 2020

프러시안 블루 유사체(Prussian blue analogue)중 가격이 낮은 철(Fe)을 기반으로 하는 Fe₂(CN)₆와 Na_xFe₂(CN)₆를 침전법으로 합성하여 리튬이온 이차전지용 양극재료로 사용하고자 하였다. Fe₂(CN)₆는 34.6 mAh g^-1의 낮은 가역용량을 발현하였으나, 소듐이 포함된 Na_xFe₂(CN)₆는 방전을 먼저 진행하는 경우에 107.5 mAh g^-1의 가역용량을 나타내고, 충전을 먼저 진행하여 구조 내의 소듐을 제거한 후에 사용하는 경우에는 더 높은 용량인 114.1 mAh g^-1의 가역용량을 발현하였으며 사이클 수명도 더욱 향상되었다. 그리고, Na_xFe₂(CN)₆의 합성과정에서 0℃, 상온, 60℃의 각각 다른 반응온도를 적용하여 합성하였다. 합성온도에 상관없이 Na_xFe₂(CN)₆는 유사한 초기 가역용량을 나타내었으나, 낮은 온도에서 합성된 경우일 수록 결정자의 크기가 작게 형성되었고, 향상된 사이클 수명을 나타내었다. 0℃에서 합성된 시료의 경우가 가장 사이클 수명이 우수하여 120번째 사이클에서 86.4 mAh g^-1의 용량을 나타내며 초기용량의 76.8%를 유지하였다.

• Journal of Applied Biological Chemistry
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• 제52권3호
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• pp.121-125
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• 2009

고추역병에 대한 길항미생물로 선발된 Bacillus subtilis AH18과 Bacillus licheniformis K11의 토양미생물 생태에 미치는 영향을 조사하기 위하여 이들 미생물을 단독 또는 복합으로 토양에 처리한 후 토양미생물상의 변화를 관찰하였다. 토양미생물 생태의 변화는 토양에서 인지질 지방산을 추출한 후 전체 지방산과 지표 지방산의 상대적 비율로 분석하였다. 전체적 인지질 지방산 구성과 각 지표 지방산 분석에 의해서 B. subtilis AH18 처리구는 무처리 대조구와 완전히 구분되었다. 전체 토양미생물상을 B. subtilis AH18 처리가 바꾸었고 세균 비율을 감소시켰으며, 곰팡이세균 비율을 높였으며, 그램음성균/그램양성균의 비율을 낮추었으며, 혐기성균/호기성균의 비율은 증가시켰다. 또한 불량환경 적응성을 의미하는 cy19:0/18:$1{\omega}7c$ 지방산비율과 단불포화지방산/포화지방산 비율도 B. subtilis AH18 처리구가 증가시켰다. 이에 반하여 B. licheniformis K11 처리나 두 미생물의 동시 처리는 전술한 토양미생물 지표에 큰 영향을 미치지 않았다. 따라서 지방산 분석을 토양미생물상 분석에서 B. subtilis AH18의 단용처리는 미생물을 처리하지 않은 대조구에 비하여 토양미생물상을 뚜렷이 바꾸었지만, B. subtilis AH18가 B. licheniformis K11와 혼용되었을 때는 토양미생물상 변화에 미치는 영향이 적었다. 따라서 이들 두 미생물을 동시에 처리할 경우 고추역병 방제와 토양미생물 생태 보존의 두 목적을 동시에 이룰 수 있을 것으로 기대된다.

• 에너지공학
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• 제23권4호
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• pp.1-8
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• 2014

본 연구에서 세계 환경오염 지정유해물질을 함유한 납축전지와 니켈 카드뮴(Ni-Cd) 축전지를 대체할 수 있는 대용량 니켈 금속수소(Ni-MH) 축전지를 이용하여, 디젤발전기 시동을 걸기위해 80Ah 전지를 병렬로 연결하여 160Ah의 Ni-MH 축전지를 제작하였다. 160Ah 전지에 적합한 전극을 개발하기 위하여 3성분계의 전해질 조성이 요구되었으며, 그 후, 고율방전을 평가하였다. 음극 성능의 개선을 위하여, Zn을 첨가하였다. 160Ah급 축전지로 디젤발전기의 시동을 위한 다양한 실험을 통하여 평가를 하였으며, 최종적으로 디젤발전기의 시동이 가능함을 확인하였다.

• Toxicological Research
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• 제31권4호
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• pp.339-345
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• 2015

CYP1A1 is a phase I xenobiotic-metabolizing enzyme whose expression is mainly driven by AhR. Endosulfan is an organochlorine pesticide used agriculturally for a wide range of crops. In this study, we investigated the effect of endosulfan on CYP1A1 expression and regulation. Endosulfan significantly increased CYP1A1 enzyme activity as well as mRNA and protein levels. In addition, endosulfan markedly induced XRE transcriptional activity. CH-223191, an AhR antagonist, blocked the endosulfan-induced increase in CYP1A1 mRNA and protein expression. Moreover, endosulfan did not induce CYP1A1 gene expression in AhR-deficient mutant cells. Furthermore, endosulfan enhanced the phosphorylation of calcium calmodulin (CaM)-dependent protein kinase (CaMK) and protein kinase C (PKC). In conclusion, endosulfan-induced up-regulation of CYP1A1 is associated with AhR activation, which may be mediated by PKC-dependent pathways.

• Asian Pacific Journal of Cancer Prevention
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• 제13권11호
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• pp.5445-5450
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• 2012

Although benign uterine leiomyomata (LMA) is the most common reproductive tumor in premenopausal women, its etiology is largely unknown. We aimed in the present study to demonstrate the potential role of environmental factors with estrogenic activity in tumor etiology by focusing on the role of aryl hydrocarbon receptor (AhR) which mediates the effects of many environmental endocrine disruptors and contributes to the loss of normal ovarian function in polluted environments. This case-control study aimed to compare the interactions between AhR and lifestyle factors in a clinical setting for the first time among 138 newly diagnosed LMA patients and 138 normal controls who lived in Tehran and Mashhad, respectively, during the last 10 years. To conduct immunohistochemical studies using appropriate monoclonal antibodies, 30 cases were selected retrospectively from 2009-2011 from the pathology departments of two university hospitals in Tehran. Although the levels of sex steroid receptors were similar in adjacent myometrium and uterine leiomyomas of all cases, AhR was significantly overexpressed (p=0.034, OR=1.667) in uterine LMA and this overexpression was correlated with living in Tehran [(p=0.04, OR=16 (1.216-210.58)], smoking[P=0.04, OR=2.085 (1.29-3.371)], living near polycyclic aromative hydrocarbon producing companies [p=0.007, OR=2.22 (1.256-3.926)] and eating grilled meat [p=0.042, OR=1.28 (1.92-3.842)]. Our study contributes to the understanding of the effects of EDCs on AhR levels as well as women's health and points out possible risk factors for the development and growth of uterine LMA. It seems that the development of LMA could be the result of interactions between hormonal and environmental factors.

• Biomolecules & Therapeutics
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• 제29권2호
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• pp.220-226
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• 2021

The role of particulate matter (PM) in health problems including cardiovascular diseases (CVD) and pneumonia is becoming increasingly clear. Polycyclic aromatic hydrocarbons, major components of PM, bind to aryl hydrocarbon receptor (AhRs) and promote the expression of CYP1A1 through the AhR pathway in keratinocytes. Activation of AhRs in skin cells is associated with cell differentiation in keratinocytes and inflammation, resulting in dermatological lesions. Oleanolic acid, a natural component of L. lucidum, also has anti-inflammation, anticancer, and antioxidant characteristics. Previously, we found that PM10 induced the AhR signaling pathway and autophagy process in keratinocytes. Here, we investigated the effects of oleanolic acid on PM10-induced skin aging. We observed that oleanolic acid inhibits PM10-induced CYP1A1 and decreases the increase of tumor necrosis factor-alpha and interleukin 6 induced by PM10. A supernatant derived from keratinocytes cotreated with oleanolic acid and PM10 inhibited the release of matrix metalloproteinase 1 in dermal fibroblasts. Also, the AhR-mediated autophagy disruption was recovered by oleanolic acid. Thus, oleanolic acid may be a potential treatment for addressing PM10-induced skin aging.

• Restorative Dentistry and Endodontics
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• 제18권1호
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• pp.156-172
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• 1993

The purpose of this study was to evaluate for the cytotoxicity of root canal sealers - Tubliseal, N2, AH26, and Sealapex - on fibroblasts cultivated from human periodontal ligament. Succinate dehydrogenase activity test and $^{51}Cr$ release test were performed to evaluate the shortterm cytotoxicity. According to l,3 and 6 days vital cell count and $^{14}C$-leucine incorporation rate to fibroblasts were evaluated. The results of this study were as follows: 1. In the test of SDH activity by millipore filter method, Sealapex showed mild cytotoxicity but Tubliseal, N2 and AH26 showed severe cytotoxicity. 2. In $^{51}Cr$ release test, Tubliseal was the most cytotoxic sealer tested, and rank ordered the relative cytotoxicity of the other sealers tested as follows: AH26, N2, Sealapex. 3. In the test of viable cell count, cytotoxicity in Tubliseal was continued because vital cell number reduced with time. Because vital cell was not showed in N2 and AH26 at 1 day, it was recognized that N2 and AH26 exhibited severe cytotoxicity. In Sealapex, vital cell number increased remarkably with time, so it showed that cytotoxicity decreased with time. 4. In $^{14}C$-leucine incorporation rate test, protein sythesis was not produced in Tubliseal, N2 and AH26 after 3 days, it showed that cytotoxicity in Tubliseal, N2 and AH26 was severe. Although protein synthesis in Sealapex decreased with time, it continued after 6 days. Therefore Sealapex has been exhibited mild cytotoxicity.

• Journal of Electrochemical Science and Technology
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• 제12권4호
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• pp.398-405
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• 2021

To fabricate a full-scale pilot model of the cost-effective Na-(Ni,Fe)Cl₂ cell, a Na-beta-alumina solid electrolyte (BASE) was developed by applying a one-step synthesis cum sintering process as an alternative to the conventional solid-state reaction process. Also, Fe metal powder, which is cheaper than Ni, was mixed with Ni metal powder, and was used for cathode material to reduce the cost of raw material. As a result, we then developed a prototype Na-(Ni,Fe)Cl₂ cell. Consequently, the Ni content in the Na-(Ni,Fe)Cl₂ cell is decreased to approximately (20 to 50) wt.%. The #1 prototype cell (dimensions: 34 mm × 34 mm × 235 mm) showed a cell capacity of 15.9 Ah, and 160.3 mAh g^-1 (per the Ni-Fe composite), while the #2 prototype cell (dimensions: 50 mm × 50 mm × 335 mm) showed a cell capacity of 49.4 Ah, and 153.2 mAh g^-1 at the 2^nd cycle.

• Environmental Analysis Health and Toxicology
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• 제21권1호
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• pp.13-19
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• 2006

화학적 예방효과가 있는 식물성 에스트로젠은 다양한 환성을 나타내며 여러 세포 수용체와 상호작용한다. Genistein은 isoflavone의 주요물질 중의 하나로 콩류에 존재하며 대표적인 식물성 에스트로젠이다. 본 논문에서는 유방암 세포주인 MCF-7에서 aryl hydrocarbon receptor(AhR)에 의해 매개되는 발암물질 활성화 경로에 대한 genistein의 영향을 살펴보았다. 세포에 genistein을 처리할 경우 cytochrome P450 1A1(CYP1A1) 약물대사효소의 특이적인 효소반응인 7-ethoxyresorufin O-deethylase (EROD) 활성도와 CYP1A1의 유전자 발현이 genistein의 농도 의존적으로 증가하였다. Genistein과 발암물질인 방향족탄화 수소 7, 12-dimethylbenz[a]anthracene(DMBA)를 동시 처리하였을 경우 DMBA에 의해 유도되어 증가된 EROD활성도와 CYP1A1의 유전자 발현이 genistein에 의해 감소하였다. 랫트의 간에서 분리한 세포질을 이용하여 genistein과 AhR의 대표적인 ligand인 2,3,7,8-tetrachlorodibenzo-p-dioxin과 경쟁적 결합에 대한 영향을 조사한 결과 genistein이 AhR에 경쟁적으로 결합함을 알 수 있었다. 이러한 결과들은 genistein이 천연 AhR ligand임을 암시한다. 따라서, 식물성 에스트로젠인 genistein은 AhR경로의 길항제/항진제로 작용할 수 있을 것으로 사료된다.

• 대한본초학회지
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• 제25권4호
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• pp.31-37
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• 2010

Objects : This study was performed in order to evaluate the effects of Agrimoniae herba (AH) ethanol extract on intrastriatal hemorrhage (ISH). Method : ISH was induced by the stereotaxic intrastriatal injection of bacterial collagenase type IV in Sprague-Dawley rats. AH was orally given once a day for 3 days after ISH. Hematoma volume and percentage edema were examined. Immunohistochemistry was processed for iNOS, c-Fos, MMP-9, and MMP-12 expressions in the brain sections and each immuno-labeling were calculated with image analysis. Results : results are as follows; 1. AH reduced the hematoma volume and percentage edema of the ISH-induced rat brain. 2. AH swollen apoptotic bodies and neurons in the peri-hematoma regions of the ISH-induced rat brain. 3. AH significantly reduced c-Fos, MMP-9 and MMP-12 positive cells in the peri-hematoma regions of the ISH-induced rat brain. 4. AH swollen iNOS expressions in the peri-hematoma regions of the ISH-induced rat brain. Conclusion : These results suggest that AH plays an anti-apoptotic neuroprotective effect through control of ISH, suppression of c-Fos, and down-regulation of MMP-9 and MMP-12 expressions in the brain tissues.