• 한국재료학회지
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• 제27권4호
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• pp.192-198
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• 2017

Carbon nanofiber (CNF) is used as an electrode material for electrical double layer capacitors (EDLCs), and is being consistently researched to improve its electrochemical performance. However, CNF still faces important challenges due to the low mesopore volume, leading to a poor high-rate performance. In the present study, we prepared the unique architecture of the activated mesoporous CNF with a high specific surface area and high mesopore volume, which were successfully synthesized using PMMA as a pore-forming agent and the KOH activation. The activated mesoporous CNF was found to exhibit the high specific surface area of $703m^2g^{-1}$, total pore volume of $0.51cm^3g^{-1}$, average pore diameter of 2.9 nm, and high mesopore volume of 35.2 %. The activated mesoporous CNF also indicated the high specific capacitance of $143F\;g^{-1}$, high-rate performance, high energy density of $17.9-13.0W\;h\;kg^{-1}$, and excellent cycling stability. Therefore, this unique architecture with a high specific surface area and high mesopore volume provides profitable synergistic effects in terms of the increased electrical double-layer area and favorable ion diffusion at a high current density. Consequently, the activated mesoporous CNF is a promising candidate as an electrode material for high-performance EDLCs.

• Applied Biological Chemistry
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• 제29권3호
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• pp.241-247
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• 1986

쌀밥 품질의 영향 요인을 규명하기 위하여 밥 짓기 과정중 밥과 밥물의 상호 관계를 분석하고, 저급의 장립종 밀양 23호의 밥맛 증진의 수단으로 새로운 밥짓기 방법을 제시하였다. 밥짓기 과정중 밥과 밥물의 높이 변화를 측정하였다. 끊는점 부근에서 밥물이 급격히 감소하고, 이어서 농축된 밥물이 밥알 표면에 엷은 피막층을 형성함을 관찰할 수 있었다. 피막 보강 물질로 찹쌀분 1,2%(W/W)를 첨가 한 후 밥짓기를 향한 결과, 피막이 크게 보강되었으며 이렇게 제조된 밥은 윤기와 외관이 향상되고 수분 함량이 증가하였으며 밥짓기중 가용성 쌀 고용분 함량의 용출을 감소시킬 수 있었다. 밥알 피막의 형성은 밥짓기의 최종단계에서 밥알의 진동과 밥물의 고형분 농도와 유관함을 보였고, 밥의 음질 결정의 중요 요소로 작용할 수 있음을 제안하였다.

• 한국응용곤충학회지
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• 제41권1호
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• pp.49-53
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• 2002

Paenibacillus larvae는 Gram양성의 내생포자 형성 세균으로, 꿀벌의 질병 중 가장 심각한 피해를 입히는 미국부저병(AFB)의 원인균이다. 이 P. larvae를 발병전인 봉군 또는 애벌레에서 보다 빠르게 검출하기 위하여 기니아피그를 이용하여 이 병원균에 대한 다클론 항체를 제작하였고 또한 그 항체의 성능을 평가하였다 제작된 항체를 이용한 ELISA검색법을 개발한 후, 다수의 P. larvae균주를 검사하였다. 그 결과 P. larvae ATCC 25748의 균체를 사용하여 제작된 항체는 ATCC 9545 (대표균주), ATCC 25747, 국내 분리 균주인 SJl5등과 높은 항체 친화성을 나타내었으며. 다른 세균 종들과는 반응하지 아니하였다. 또한 이 ELISA검색법은 미국 부저병의 현장검사에 적용하기 위하여 사용되었으며, 그 결과로 본 연구에서 제시하는 항체는 벌집 내 또는 애벌레 내에 존재하는 P. larvae의 빠른 동정과 모니터 링에 매우 유용함을 보여주었다.

• 한국환경보건학회지
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• 제36권3호
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• pp.236-246
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• 2010

In preparative anti-corrosive coating experiments, polyaniline was obtained by reacting an oxidizing agent with the monomer aniline. Further, the primer coating was prepared using a variety of widely-used materials such as urethane resin. For the top coating, epoxy resin and acrylic urethane resin were used. Characteristics of the coatings were assessed according to KS and ASTM specifications, and the structure of the polyaniline was characterized using FT-IR and TGA. For analysis of anti-corrosive properties in salt-spray experiments, measurements of the oxidation state of iron and surface atomic analysis were conducted using XPS and SEM-EDX. Unlike general anti-corrosive coatings which exhibit anti-corrosive effects only as a primer coating, the anti-corrosive coatings using polyaniline as the anti-corrosive pigment showed a marked synergistic effect with the top coatings. In other words, the top coatings not only produce a fine view effect, but also increase, through interaction with the primer coatings, the resistance to diffusion of corrosive factors from the external environment. It was also found that, unlike the heavy metal oxide-forming layer of the passive barrier alone, the polyaniline anti-corrosive pigment oxidized iron at the interface with the iron substrate to form a passive barrier in the oxidic layer, and itself formed a potential barrier layer with anti-corrosive factors from the external environment. Although the passive layer was damaged, the damaged area did not become completely oxidized iron; on the contrary, it showed a tendency to reduction. This can be interpreted such that a passive layer is formed again on the damaged area, and that at the same time there is a tendency to self-healing.

• 한국균학회소식:학술대회논문집
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• 한국균학회 2016년도 춘계학술대회 및 임시총회
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• pp.27-27
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• 2016

The ascomycete fungus Fusarium graminearum is the most common pathogen of Fusarium head blight (FHB), a devastating disease for major cereal crops worldwide. FHB causes significant crop losses by reducing grain yield and quality as well as contaminating cereals with trichothecenes and zearalenone (ZEA) that pose a serious threat to animal health and food safety. ZEA is a causative agent of hyperestrogenic syndrome in mammals and can result in reproductive disorders in farm animals. In F. graminearum, the ZEA biosynthetic cluster is composed of four genes, PKS4, PKS13, ZEB1, and ZEB2, which encode a reducing polyketide synthase, a nonreducing polyketide synthase, an isoamyl alcohol oxidase, and a transcription factor, respectively. Although it is known that ZEB2 primarily acts as a regulator of ZEA biosynthetic cluster genes, the mechanism underlying this regulation remains undetermined. In this study, two isoforms (ZEB2L and ZEB2S) from the ZEB2 gene in F. graminearum were characterized. It was revealed that ZEB2L contains a basic leucine zipper (bZIP) DNA-binding domain at the N-terminus, whereas ZEB2S is an N-terminally truncated form of ZEB2L that lacks the bZIP domain. Interestingly, ZEA triggered the induction of both ZEB2L and ZEB2S transcription. In ZEA producing condition, the expression of ZEB2S transcripts via alternative promoter usage was directly or indirectly initiated by ZEA. Physical interaction between ZEB2L and ZEB2L as well as between ZEB2L and ZEB2S was observed in the nucleus. The ZEB2S-ZEB2S interaction was detected in both the cytosol and the nucleus. ZEB2L-ZEB2L oligomers activated ZEA biosynthetic cluster genes, including ZEB2L. ZEB2S inhibited ZEB2L transcription by forming ZEB2L-ZEB2S heterodimers, which reduced the DNA-binding activity of ZEB2L. This study provides insight into the autoregulation of ZEB2 expression by alternative promoter usage and a feedback loop during ZEA production.

• Genomics & Informatics
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• 제14권2호
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• pp.53-61
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• 2016

Toxoplasma gondii is an intracellular Apicomplexan parasite and a causative agent of toxoplasmosis in human. It causes encephalitis, uveitis, chorioretinitis, and congenital infection. T. gondii invades the host cell by forming a moving junction (MJ) complex. This complex formation is initiated by intermolecular interactions between the two secretory parasitic proteins-namely, apical membrane antigen 1 (AMA1) and rhoptry neck protein 2 (RON2) and is critically essential for the host invasion process. By this study, we propose two potential leads, NSC95522 and NSC179676 that can efficiently target the AMA1 hydrophobic cleft, which is a hotspot for targeting MJ complex formation. The proposed leads are the result of an exhaustive conformational search-based virtual screen with multilevel precision scoring of the docking affinities. These two compounds surpassed all the precision levels of docking and also the stringent post docking and cumulative molecular dynamics evaluations. Moreover, the backbone flexibility of hotspot residues in the hydrophobic cleft, which has been previously reported to be essential for accommodative binding of RON2 to AMA1, was also highly perturbed by these compounds. Furthermore, binding free energy calculations of these two compounds also revealed a significant affinity to AMA1. Machine learning approaches also predicted these two compounds to possess more relevant activities. Hence, these two leads, NSC95522 and NSC179676, may prove to be potential inhibitors targeting AMA1-RON2 complex formation towards combating toxoplasmosis.

• 한국약용작물학회지
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• 제15권1호
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• pp.21-25
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• 2007

해당화 뿌리는 우리나라 민간에서 당뇨병 치료제로 사용되는 약용식물이다. Bromobenzene으로 간독성을 유발한 흰쥐에 뿌리에서 분리한 화합물인 (+)-catechin을 경구투여하여 bromobenzene대사계에 미치는 효소활성을 간독성 물질인 bromobenzene 3,4-oxide 생성에 관여하는 효소인 aminopyrine N-demetylase와 aniline hydroxylase와 독성 epoxide 대사중간체를 무독화 시키는 epoxide hydrolase와 glutathione S-transferase에 활성을 관찰하였다. (+)-Catechin의 투여가 aminopyrine N-demetylase, aniline hydroxylase 및 glutathione S-transferase에 활성에는 영향을 주지 못하였으나, epoxide hydrolase는 positive control로 사용한 ascorbic acid에 미치지 못하지만, bromobenzene 처리군 보다 39% 효소활성을 회복 시켰다. 따라서, (+)-catechin은 간독성 물질을 무독화시키는 epoxide hydrolase의 활성을 회복시켜 간보호 활성을 나타냄을 알 수 있었으며, 해당화에서 분리한 사포닌 성분인 rosamultin도 이효소의 활성을 증가시킴으로 인해 보호활성을 나타내는 것으로 보고된바 있다.

• 한국표면공학회지
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• 제49권4호
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• pp.331-338
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• 2016

In this work, anodic oxidation behavior of AZ31 Mg alloy was studied as a function of $Na_2CO_3$ concentration in electrolyte by voltage-time curves and observation of surface appearances and morphologies after the anodic treatments, using optical microscopy and confocal scanning laser microscopy (CSLM). The voltage-time curves of AZ31 Mg alloy surface and surface appearances after the anodic treatments showed three different regions with $Na_2CO_3$ concentration : region I, below 0.2 M $Na_2CO_3$ where shiny surface with a number of small size pits; region II, between 0.4 M and 0.6 M $Na_2CO_3$ where dark surface with relatively low number of large size burned or dark spots; region III, more than 0.8 M $Na_2CO_3$ where bright surface with or without large size dark spots were obtained. The anodically treated AZ31 Mg alloy surface became significantly brightened with increasing $Na_2CO_3$ concentration from 0.5 M to 0.8 M which was attribute to the formation of denser and smoother surface films. Pits and porous protruding reaction products were found at relatively large size and small size spots, respectively, on the AZ31 Mg alloy surface in low concentration of $Na_2CO_3$ less than 0.2 M. The formation of pits is attributed to the result of repetition of the formation and detachment of porous anodic reaction products. Based on the experimental results obtained in this work, it is concluded that more uniform, denser and smoother surface of AZ31 Mg alloy could be obtained at more than 0.8 M $Na_2CO_3$ concentration if there is no other oxide forming agent.

• 한국지능시스템학회논문지
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• 제27권1호
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• pp.7-14
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• 2017

이론적으로 분산 비동기 통신 환경에서 공통믿음 또는 공통지식의 형성은 불가능하다고 받아들여져 왔으나, 서로 신뢰하는 에이전트 그룹에서는 비동기 통신을 사용하더라도 데드라인이 있는 명제들은 공통믿음이 될 수 있고 이를 바탕으로 한 추론이 가능함을 보여준다. 일반적으로 멀티에이전트 환경에서 공통믿음의 형성은 통신의 문제로 접근하며 통신 시간의 제약이 없는 시스템 상에서는 공통믿음이 형성되지 않는다는 공통믿음 역설 문제를 느슨한 정밀도를 적용하고 필요한 요구조건을 완화시켜 공통믿음을 형성 할 수 있음을 카카오톡 채팅방 모델을 통해 확인한다. 또한 카카오톡 채팅방 모델의 각 에이전트에 추론 기능을 구현하여 생성된 공통믿음을 알고 있는지에 관한 질의를 통해 공통믿음임을 확인하는 추론 기능을 실험하였다. 분산 멀티에이전트 환경에서 공통믿음의 표현과 추론을 메타논리 프로그래밍으로 형식화하였으며, 카카오톡 채팅방 모델을 통해 비동기 통신을 사용하는 분산 에이전트 그룹이 공통믿음을 형성할 수 있음을 실험적으로 보였다.

• 대한금속재료학회지
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• 제48권7호
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• pp.625-629
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• 2010

This study investigates the effects of porosity on the thermal stability and the thermal shock resistance of a porous nozzle used for blowing an inert gas. The samples of $Al_2O_3-SiO_2-ZrO_2$ system, which had the apparent porosity of 16~30% and bulk density of $2.6{\sim}3.2g/cm^3$, were prepared by adding different graphite contents (5, 10, 20 wt%) as a pore-forming agent. The thermal shock test was conducted at ${\Delta}T=500$, 1000, and $1400^{\circ}C$ also and the thermal stability was also carried out at 1550, 1600, and $1650^{\circ}C$ for 5 hrs. The specimen contained 10 wt% graphite had uniform pore size distribution, whereas the specimen with 20 wt% graphite showed non-uniform pore size distribution. As a result of thermal shock test, the specimen containing 10 wt% graphite appears to have higher mechanical strength than the other specimens (5, 20 wt% graphite). Both the 5 wt% and 20 wt% graphite specimens developed a non-uniform pore size distribution and cracks that were generated by intensive thermal stress.