Optical Properties of Pt-TiO₂, Catalyst and Photocatalytic Activities for Benzene Decomposition

Lee, Byung-Yong,Park, Sang-Hyuk,Lee, Sung-Chul,Kang, Misook,Park, Chang-Ho,Choung, Suk-Jin 한국화학공학회 2003 Korean Journal of Chemical Engineering Vol.20 No.5

In order to improve the photocatalytic decomposition activity of benzene, which has bee regarded as a typical volatile organic compound in air, TiO₂ catalysts modified with metals (Pt, Cu, and Fe) were prepared and tested. Certain correlations between the photocatalytic activities and the optical properties of those catalysts were also found and discussed by using UV-visible spectroscopy and a photoluminescence spectroscopy. Among the metal impregnated TiO₂, the Pt impregnated TiO₂showed the best activity and it was even better than that of P-25 which is widely used in commercial applications. For the various metal impregnated TiO₂samples, certain proportional relationships were found between the observed photoluminescence values and photocatalytic activities. On the other hand, in UV-visible sperctra for metal impregnated TiO₂samples, the transmittance value was reduced depending upon the loading of metals. It was thought that photocatalytic activity increases from initial reaction state because the number of photo-excited electrones, which exist at Pt surface augment due to the band gap energy change of Pt and TiO₂ by sintering and light energy-absorbed electrones excited casily to conduction. In conclusion, it was confirmed that the enhanced photocatalytic activity for high metal loading on TiO₂is related with the high concentration of excited electrons, which could be monitored through UV-visible spectra.

Path Dependence In North Korean Military Negotiation Agendas

( Misook Lee ) 이화여자대학교 통일학연구원 2018 Journal of peace and unification Vol.8 No.1

Analyzing the agendas of the North Korean military negotiations, we see that they were varied according to situations, but their objective for negotiations toward South Korea, “maintaining the North Korean system” did not change. In the early 1990s, proposals for “important military negotiations,” such as nonaggression and disarmament were mainly on the table, but they used to end up as declaratory military issues showing the characteristics of pseudo-military negotiations. However, in the early 2000s, such general military negotiations as connecting railways and roads and building military confidence were proposed and carried out to make them look like realistic negotiations, though they were still locked in the box of maintaining the regime. Therefore, the change was not in the character of the negotiations, but simply the negotiation items varied in favor of the situations in order to achieve the goal of “protecting the system.” As Thelen pointed out, the change was not targeted for the core element of maintaining the North Korean regime. Instead, the change was made in the military negotiation agendas in order to secure the regime in terms of the North’s strategy toward South Korea’s negotiation, thereby keeping up its path dependence.

Remarkable photoconversion of carbon dioxide into methane using Bi-doped TiO₂ nanoparticles prepared by a conventional sol–gel method

Lee, Jae Hyung,Lee, Homin,Kang, Misook Elsevier 2016 Materials Letters Vol.178 No.-

<P><B>Abstract</B></P> <P>Bi ions were inserted into a TiO<SUB>2</SUB> framework in order improve the CO<SUB>2</SUB> reduction. The x-mol% Bi ion-incorporated TiO<SUB>2</SUB>s were prepared by a conventional sol–gel method, and characterized by XRD, TEM, UV–visible spectroscopy, photocurrent spectroscopy, and CO<SUB>2</SUB>-TPD. The adsorption of CO<SUB>2</SUB> was significantly increased on Bi–TiO<SUB>2</SUB>s, which demonstrated superior photocatalytic behavior compared to that of pure TiO<SUB>2</SUB>. The 5.0mol% Bi–TiO<SUB>2</SUB> produced 3400μmolg<SUB>cat</SUB> <SUP>−1</SUP> L<SUP>−1</SUP> CH<SUB>4</SUB> gases after an 8h reaction. The photocatalytic activity was dramatically enhanced by the improved effective CO<SUB>2</SUB> gas adsorption and by the inhibited recombination of photogenerated electron–hole pairs due to the enhanced charge separation.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The Bi ions for narrower band gap and extended charge separation were inserted to TiO<SUB>2</SUB>. </LI> <LI> The adsorption of CO<SUB>2</SUB> significantly increased on the Bi–TiO<SUB>2</SUB>. </LI> <LI> Higher CH<SUB>4</SUB> was produced on Bi–TiO<SUB>2</SUB>. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Remarkable photoconversion of carbon dioxide into methane using Bi doped TiO<SUB>2</SUB> nanoparticles prepared by a conventional sol–gel method.</P> <P>[DISPLAY OMISSION]</P>

Multilayer deposition on patterned posts using alternating polyelectrolyte droplets in a microfluidic device

Lee, Misook,Park, Wook,Chung, Changkwon,Lim, Jaehoon,Kwon, Sunghoon,Ahn, Kyung Hyun,Lee, Seung Jong,Char, Kookheon Royal Society of Chemistry 2010 Lab on a chip Vol.10 No.9

<P>We demonstrate that polyelectrolyte (PE) multilayer thin films deposited on patterned posts with incredibly large numbers of bilayers, which would not be possible with the conventional Layer-by-Layer (LbL) deposition methods, can be obtained in a short process time using alternating polyelectrolyte droplets generated in a microfluidic channel, representing a significant advantage over the conventional processes based on polyelectrolyte deposition followed by the separation of such substrates (typically colloidal particles) with centrifugation and sonication. Positively- and negatively-charged polyelectrolyte droplets were alternatively generated in a microfluidic channel by controlling the capillary number (<I>Ca</I>) as well as the fraction of dispersed phase over the continuous phase. Patterned posts, serving as the substrates for the PE deposition, were created with photo-curable polymers using the optofluidic maskless lithography. The impact of these PE droplets onto the patterned posts allowed the alternative adsorption of PEs, similar to the conventional LbL deposition methods. It was shown that the intensity of fluorescence dye tagged onto (+)-charged PEs adsorbed on the post(s), taken with confocal laser scanning microscopy, increases with deposition time and varies around the post(s). The effect of post shape and interval between the two posts for the droplet-based LbL deposition was also experimentally investigated and analyzed, in connection with the numerical simulations, to elucidate the underlying principles of relevant two-phase flows.</P> <P>Graphic Abstract</P><P>We demonstrate that polyelectrolyte (PE) multilayer thin films deposited on lithographically defined patterned posts can be achieved in a facile manner using alternating polyelectrolyte droplets generated in a microfluidic channel. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=b919753b'> </P>

Targeted Inhibition of the NCOA1/STAT6 Protein–Protein Interaction

Lee, Yeongju,Yoon, Heeseok,Hwang, Sung-Min,Shin, Min-Kyung,Lee, Ji Hoon,Oh, Misook,Im, Sin-Hyeog,Song, Jaeyoung,Lim, Hyun-Suk American Chemical Society 2017 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.139 No.45

<P>The complex formation between transcription factors (TFs) and coactivator proteins is required for transcriptional activity, and thus disruption of aberrantly activated TF/coactivator interactions could be an attractive therapeutic strategy. However, modulation of such protein–protein interactions (PPIs) has proven challenging. Here we report a cell-permeable, proteolytically stable, stapled helical peptide directly targeting nuclear receptor coactivator 1 (NCOA1), a coactivator required for the transcriptional activity of signal transducer and activator of transcription 6 (STAT6). We demonstrate that this stapled peptide disrupts the NCOA1/STAT6 complex, thereby repressing STAT6-mediated transcription. Furthermore, we solved the first crystal structure of a stapled peptide in complex with NCOA1. The stapled peptide therefore represents an invaluable chemical probe for understanding the precise role of the NCOA1/STAT6 interaction and an excellent starting point for the development of a novel class of therapeutic agents.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jacsat/2017/jacsat.2017.139.issue-45/jacs.7b08972/production/images/medium/ja-2017-089727_0005.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ja7b08972'>ACS Electronic Supporting Info</A></P>

South Korea’s Democratization Movement of the 1970s and 80s and Communicative Interaction in Transnational Ecumenical Networks

Misook Lee(이미숙) 고려대학교 한국사연구소 2014 International Journal of Korean History Vol.19 No.2

1990년대 이래 국제정치학, 사회학, 역사학 등 다양한 학문분과 내에서 트랜스내셔널 네트워크에 관한 연구가 급속히 발전해 왔다. 기존의 연구들은 선진국 혹은 국제적인 비정부기구들이 개발도상국을 “돕는다”고 가정하는 하향식 접근을 취해왔다. 그러나 이러한 일방향적인 접근만으로는 트랜스내셔널한 활동가들의 네트워크 역학을 온전히 설명해 낼 수 없다. 본 연구는 한국 민주화 운동을 지지하였던 다양한 집단들 간의 ‘상호작용’에 초점을 맞춤으로써 트랜스내셔널 네트워크의 역학을 보다 심도 있게 이해하고자 한다. 특히 한국 기독교인들과 공조하였던 일본 및 미국의 트랜스내셔널한 정보교환 네트워크의 형성과 활동을 탐구한다. 또한, 본 연구는 투쟁하는 타자와의 트랜스내셔널 네트워크의 형성이 갖는 정치적 함의를 고찰하고자 한다. 본 연구를 통해, 트랜스내셔널 네트워크는 활동가들간의 의사소통적 상호작용을 통해, 활동가들의 서로 다른 위치를 규정하는 구조적 관계를 문제시하는 성찰적 작용이 가능하다는 것을 밝혔다. Transnational network studies in international relations, sociology, and history have grown rapidly since the 1990s. Research often tends to take a top-down (North-South) approach in which developed countries or international non-governmental organizations (INGOs) are assumed to “help” the developing ones. However, this one-way approach cannot fully explain the dynamics of transnational activist networks. The following paper aims to better understand the dynamics of transnational networks by focusing on the ‘communicative interaction’ among various groups supporting the democratization movement in South Korea. It specifically investigates the formation and activities of transnational information exchange networks in Japan and the United States that worked with Korean Christians. In addition, this research examines the meaning and political implications of forming transnational networks with struggling others; transnational networks can work reflexively by problematizing the structural relationships among differently situated actors.

Probiotic characteristics of <i>Bacillus</i> strains isolated from Korean traditional soy sauce

Lee, Sangki,Lee, Joongjae,Jin, Yong-Ik,Jeong, Jin-Cheol,Chang, Yoon Hyuk,Lee, Youngseung,Jeong, Yoonhwa,Kim, Misook Elsevier 2017 FOOD SCIENCE AND TECHNOLOGY -ZURICH- Vol.79 No.-

<P>The objective of this work was to isolate Bacillus strains from Korean traditional soy sauces, and evaluate them for probiotic potential and safety. Three Bacillus strains, MKSK-E1, MKSK-J1 and MKSK-M1, were selected which were highly resistant to simulated gastrointestinal tract conditions, and showed antimicrobial activity against Bacillus cereus, Listeria monocytogenes, Staphylococcus aureus and Escherichia coli. MKSK-M1 possessed the highest relative survival rate, with 96.0% survival in 0.1% pepsin solution (pH 2.0) and 99.3% survival in 3% bile salt solution for 3 h. All three strains exhibited amylase and protease activity, and utilized more than 19 carbohydrates among 49 tested carbohydrates. MKSK-E1 inhibited the growth of 11 of 13 tested foodborne pathogens. All three selected strains possessed strong antimicrobial activity against E. coli and B. cereus. They had antibiotic susceptibility against 8 tested antibiotics. Also, all strains were non-hemolytic on sheep blood, and non-biogenic amine producers. The results of this work indicate that MKSK-El, J1 and Ml could be used as probiotic cultures for human consumption and animal feeds and as probiotic starter cultures in food industries. (C) 2016 Elsevier Ltd. All rights reserved,</P>

Converting One-Face α-Helix Mimetics into Amphiphilic α-Helix Mimetics as Potent Inhibitors of Protein-Protein Interactions

Lee, Ji Hoon,Oh, Misook,Kim, Hyun Soo,Lee, Huisun,Im, Wonpil,Lim, Hyun-Suk American Chemical Society 2016 ACS Combinatorial Science Vol.18 No.1

<P>Many biologically active alpha-helical peptides adopt amphiphilic helical structures that contain hydrophobic residues on one side and hydrophilic residues on the other side. Therefore, alpha-helix mimetics capable of mimicking such amphiphilic helical peptides should possess higher binding affinity and specificity to target proteins. Here we describe an efficient method for generating amphiphilic alpha-helix mimetics. One-face alpha-helix mimetics having hydrophobic side chains on one side was readily converted into amphiphilic alpha-helix mimetics by introducing appropriate charged residues on the opposite side. We also demonstrate that such two-face amphiphilic alpha-helix mimetics indeed show remarkably improved binding affinity to a target protein, compared to one-face hydrophobic alpha-helix mimetics. We believe that generating a large combinatorial library of these amphiphilic alpha-helix mimetics can be valuable for rapid discovery of highly potent and specific modulators of protein-protein interactions.</P>

Prevention of 6-hydroxydopaminergic Neuronal Apoptosis by Leaf Extract of Allium senescens

Seunghyup Lee,Jiwon Choi,Kyeonghwa Lee,Sunyoung Gu,Sungmin Cho,Yoseob Kim,Inyong Kim,Hea-Yeon Yun,Boyong Kim,Youngseung Lee,Misook Kim,Yoonhwa Jeong 한국식품영양과학회 2018 한국식품영양과학회 학술대회발표집 Vol.2018 No.10

뉴 미디어아트의 전개 양상과 담론

이미숙 ( Lee Misook ) 아시아문화학술원 2017 인문사회 21 Vol.8 No.6

본 논문은 기존의 예술의 표현 도구를 무너뜨리고 디지털 매체를 도입한 뉴 미디어아트의 시대적 배경과 개념 및 사회 전반적으로 확산되어 현대인의 일상생활과 밀접하게 연결된 디지털 뉴미디어 매체의 확산범위와 뉴 미디어아트 작품에서 두드러지는 특성이 무엇인지에 대해 작품을 사례로 살펴본다. 이를 바탕으로 예술을 표현하는 도구가 뉴 미디어아트에서 AI 시대 예술로 전환됨을 제시하고 뉴 미디어아트의 한계를 주요 쟁점에 대해 시사한다. 그리고 AI 시대 예술의 표현 도구로 활용되는 인공지능은 뉴 미디어아트와는 다른 새로운 아트가 등장되어 시작되고 있음을 예고한다. 또한 새롭게 다가올 표현 도구에 대해 제시하였다. 더불어 향후 새로운 AI 시대의 개념과 이에 적합한 예술 명칭을 위한 추가적인 논의가 왕성하게 이루어질 수 있는 토대가 될 것이다. In this paper, we propose a background and concept in new digital media art that breaks down existing artistic expression tools historical, the spreading range of new media art connected with modern daily life, and outstanding characteristic using the case in new media art. Based on this, I suggests that the tools of expressing art are transformed from new media art to AI age art and I proposes the limitations of new media art to major issues. Artificial intelligence, which is used as an expression tool of arts in AI period, predicts that new art, which is different from new media art, is starting to appear. Also I present it emerged as a new expression tool. In addition, it will serve as a basis for further discussion on the concept of the new AI era and the appropriate name for the art.