• Title/Summary/Keyword: helix

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NMR and Circular Dichroism Studies on Human CD99 Transmembrane Domain

  • Kim, Hai-Young;Shin, Joon;Shin, Young-Kee;Park, Seong-Hoe;Lee, Weon-Tae
    • Journal of the Korean Magnetic Resonance Society
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    • v.7 no.1
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    • pp.37-45
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    • 2003
  • Human CD99 is a ubiquitous 32-kDa transmembrane protein encoded by mic2 gene. Recently it has been reported that expression of a splice variant of CD99 transmembrane protein (Type I and Type II) increases invasive ability of human breast cancer cells. To understand structural basis for cellular functions of CD99 Type II, we have initiated studies on hCD99$\^$TMcytoI/ using circular dichroism (CD) and multi-dimensional NMR spectroscopy. CD spectrum of hCD99$\^$TMytoI/ in the presence of 200mM DPC and CHAPS displayed an existence ${\alpha}$-helical conformation, showing that it could form an ${\alpha}$-helix under membrane environments. In addition, we have found that the cytoplasmic domain of CD99 would form symmetric dimmer in the presence of transmembrane domain. Although it has been rarely figured out the correlation between structure and functional mechanism of hCD99$\^$TMcytoI/, the dimerization or oligomerization would play an important role in its biological function.

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NMR Structural Study of the 3'-T.G Mismatched DNA Decamer Duplex Containing the T-T (6-4) Adduct

  • Lee, Joon-Hwa;Park, Yun-Jeong;Park, Byong-Seok
    • Journal of the Korean Magnetic Resonance Society
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    • v.3 no.1
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    • pp.60-70
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    • 1999
  • The pyrimidine(6-4) pyrimidone photoproduct [(6-4) adduct] is one of the major photoproducts induced by UV irradiation of DNA and occurs at TpT sites. The (6-4) adduct is highly mutagenic and specific during translesion replication. The marked preference for insertion of A opposite the 5'-T and G opposite the 3--T of the (6-4) adducts leads to a predominantly 3'-T\longrightarrowC transition with 85% replicating error rate. In order to obtain insight into the origin of 3'-T\longrightarrowC transition induced by the (6-4) adduct, we have performed one - and two-dimensional NMR experiment. The 3'-Tof the (6-4) lesion forms the stable hydrogen bonding to the imino proton of an opposed G, which stabilizes the overall helix and diminishes the highly distorted conformation caused by the (6-4) lesion in the (6-4)/AA duplex. We proposed that the greater insertion of a G over an A opposite the 3'-T of the (6-4) lesion These results may account for the greater preference for the insertion of a G over a A opposite the 3'-T of the (6-4) lesion. Thus this insertion leads to the highly specific 3'-T\longrightarrowC multation at the (6-4) lesion site.

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An research of the error detection method and efficient recovery algorithms in the DNA double helix (DNA 이중나선에서의 오류위치 검출 방법 및 효율적인 복구 알고리즘 연구)

  • Kim, SokeHwan;Hur, Chang-Wu
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.16 no.11
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    • pp.2557-2562
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    • 2012
  • In order to maintain order in the genetic information at cells, it need ongoing monitoring and recovery system. DNA is accomplished by a combination of base pairs, Wrong base pairs is formed with a much more lower frequency than the normal DNA. if it does not modify and was accumulate, the Cells were died. In this study, mistakes of DNA replication and repair of the damaged part was introduced engineering concepts by mimicking DNA repair functions. It was presented recover the complementary part of the previously announced and presented an efficient algorithm at find and recover the complementary part.

An experimental study on the effects of an inserted coil on flow patterns and heat transport performances for a horizontal rotating heat pipe (수평 회전 히트파이프에서 내부 삽입 코일이 유동 형태 및 열전달 성능에 미치는 영향에 대한 실험 연구)

  • 이진성;김철주;김선주;문석환
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.10 no.6
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    • pp.763-772
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    • 1998
  • The effects of an inserted coil on flow patterns and heat transport performance for a horizontal rotating heat pipe have been studied experimentally. Especially, the present study is to see an internally inserted helical coil inside a RHP would lead to the same kind of results as internal fins. Visualization test conducted for an acryl tube, charged water with at a volumetric rate of 20%. When the flow kept pool regime at a low RPM(less than 1,000 RPM), the movement of coil forced the water to flow in axial direction. But this pumping effect of coil disappeared, when the pool regime changed to annular one which could be created by increasing RPM. The pumping effects for RHP with an inserted coil resulted enhancement both in condensation heat transfer coefficient and heat transport limitation, as obtained in case of using internal fins. But all these effects became negligible in the range of higher RPM(above 1,000∼1,200) with the transition of flow regime to annular flow.

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GOVERNMENT-CIVIC GROUP CONFLICTS AND COMMUNICATION STRATEGY: A TEXT ANALYSIS OF TV DEBATES ON KOREA'S IMPORT OF U.S. BEEF

  • Cho, Seong Eun;Choi, Myunggoon;Park, Han Woo
    • Journal of Contemporary Eastern Asia
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    • v.11 no.1
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    • pp.1-20
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    • 2012
  • This study analyzes messages from Korean TV debates on the conflict over U.S. beef imports and the process of negotiations over the imports in 2008. The authors have conducted a content analysis and a semantic network analysis by using KrKwic and CONCOR. The data was drawn from nine TV debates aired by three major TV networks in Korea (MBC, KBS, and SBS) from 27 April 27 2008 to 6 July 2008. The results indicate substantial differences in the semantic structure between arguments by the government and those by civic groups. We also investigated the relationship between the terms frequently used by both sides (i.e., the government and civic groups), and the terms used exclusively by one side. There was a gradual increase in the number of terms frequently used by both sides over time, from the formation of the conflict to its escalation to its resolution. The results indicate the possibility of general agreement in conflict situations.

Techno Populism and Algorithmic Manipulation of News in South Korea

  • Yoon, Sunny
    • Journal of Contemporary Eastern Asia
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    • v.18 no.2
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    • pp.33-48
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    • 2019
  • The current Moon Jai-in administration in South Korea is facing serious challenges as a result of a scandal involving the manipulation of news online. Staff in Moon's camp are suspected of manipulating public opinion by creating millions of fake news comments online, contributing to Moon being elected president. This South Korean political scandal raises a number of theoretical issues with regard to new platform technologies and media manipulation. First, the incident exposes the technological limits of blocking manipulation of the news, partly because of the nature of social media and partly because of the nature of contemporary technology. Contemporary social media is often monopolistic in nature; with the majority of people are using the same platforms, and hence it is likely that they will be subject to forms of media manipulation. Second, the Korean case of news manipulation demonstrates a unique cultural aspect of Korean society. News comments and readers' replies have become a major channel of alternative news in Korea. This phenomenon is often designated as "reply journalism," since people are interested in reading the news replies of ordinary readers equally to reading news reports themselves. News replies are considered indicators of public opinion and are seen as affecting trias politica in Korean society. Third, the Korean incident of news manipulation implicates a new form of populism in the 21st century and the nature of democratic participation. This article aims to explicate key issues in media manipulation by including wider technological, cultural, and political aspects in the South Korean news media context.

The Daily Us (vs. Them) from Online to Offline: Japan's Media Manipulation and Cultural Transcoding of Collective Memories

  • Ogasawara, Midori
    • Journal of Contemporary Eastern Asia
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    • v.18 no.2
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    • pp.49-67
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    • 2019
  • Since returning to power in 2012, the second Abe administration has pressured Japanese mainstream media in various ways, from creating the Secrecy Act to forming close relationships with media executives and promoting anti-journalism voices on social media. This article focuses on the growth of a jingoist group called the 'Net-rightists' ('Neto-uyo' in the Japanese abbreviation) on the Internet, which has been supporting the right-wing government and amplifying its historical revisionist views of Japanese colonialism. These heavy Internet users deny Japan's war crimes against neighboring Asian countries and disseminate fake news about the past, which justifies Prime Minister Shinzo Abe's hostile diplomatic policies against South Korea and China. Over the past years, the rightist online discourses have become powerful to such an extent that the editorials of major newspapers and TV reports shifted to more nationalist tones. Who are the Neto-uyo? Why have they emerged from the online world and proliferated to the offline world? Two significant characteristics of new media are discussed to analyze their successful media manipulation: cultural transcoding and perpetual rewriting of collective memories. These characteristics have resulted in constructing and reinforcing the data loops of the 'Daily Us' versus Them, technologically raising current diplomatic tensions in East Asia.

Emerging Gender Issues in Korean Online Media: A Temporal Semantic Network Analysis Approach

  • Lee, Young-Joo;Park, Ji-Young
    • Journal of Contemporary Eastern Asia
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    • v.18 no.2
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    • pp.118-141
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    • 2019
  • In South Korea, as awareness of gender equality increased since the 1990s, policies for gender equality and social awareness of equality have been established. Until recently, however, the gap between men and women in social and economic activities has not reached the globally desired level and led to social conflict throughout the country. In this study, we analyze the content of online news comments to understand the public perception of gender equality and the details of gender conflict and to grasp the emergence and diffusion process of emerging issues on gender equality. We collected text data from the online news that included the word 'gender equality' posted from January 2012 to June 2017 and also collected comments on each selected news item. Through text mining and the temporal semantic network analysis, we tracked the changes in discourse on gender equality and conflict. Results revealed that gender conflicts are increasing in the online media, and the focus of conflict is shifting from 'position and role inequality' to 'opportunity inequality'.

Transcriptional Control of Lactate Dehydrogenase A-Gene Expression during the Pre-replicative Phase of Regenerating Rat Liver (백서 재생간조직의 낙산탈수소효소 A-유전자 발현의 전사활성)

  • Kim, Hae-Young;Lee, Seung-Ki
    • YAKHAK HOEJI
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    • v.32 no.4
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    • pp.239-244
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    • 1988
  • Transcriptional rate of lactate dehydrogenase A-gene(LDH-A) during the prereplicative phase of regenerating rat liver was determined by in vitro run-off transcription assay. The results show that the transcription rate of LDH A-gene increases between 12 hours and 15 hours peaking at 13 hours after partial hepatectomy of rat liver. The increased rate of LDH A-gene transcription was interfered after DL-propranolol treatment intraperitoneally injected twice at 1 hour and 8 hours after partial hepatectomy indicating that the transcriptional control of LDH A-gene expression may be mediated by beta adrenergic receptor and cAMP as a second messenger. And also was it shown that the temporally increased rate of LDH A-gene transcription was maximum one hour after the second cAMP-surge which is known to play an important role for the initiation of DNA replication during regeneration of rat liver. And the transcriptional rate of LDH A-gene was decreased to the basal level at the time period when the hepatocytes proliferate rapidly suggesting that the induced LDH Aisozyme may be required for the initiation of DNA replication during regeneration of rat liver. These data may be supporting for the hypothesis suggesting that the induced LDH A-isozyme during the pre-replicative phase of regenerating rat liver may play bifunctional roles as a glycolytic enzyme and a helix destablizing protein as well.

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DNAchip as a Tool for Clinical Diagnostics (진단의학 도구로서의 DNA칩)

  • 김철민;박희경
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2004.04a
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    • pp.97-100
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    • 2004
  • The identification of the DNA structure as a double-stranded helix consting of two nucleotide chain molecules was a milestone in modern molecular biology. The DNA chip technology is based on reverse hybridization that follows the principle of complementary binding of double-stranded DNA. DNA chip can be described as the deposition of defined nucleic acid sequences, probes, on a solid substrate to form a regular array of elements that are available for hybridization to complementary nucleic acids, targets. DNA chips based on cDNA clons, oligonucleotides and genomic clons have been developed for gene expression studies, genetic variation analysis and genomic changes associated with disease including cancers and genetic diseases. DNA chips for gene expression profiling can be used for functional analysis in human eel Is and animal models, disease-related gene studies, assessment of gene therapy, assessment of genetically modified food, and research for drug discovery. DNA chips for genetic variation detection can be used for the detection of mutations or chromosomal abnormalities in cnacers, drug resistances in cancer cells or pathogenic microbes, histocompatibility analysis for transplantation, individual identification for forensic medicine, and detection and discrimination of pathogenic microbes. The DNA chip will be generalized as a useful tool in clinical diagnostics in near future. Lab-on-a chip and informatics will facilitate the development of a variety of DNA chips for diagnostic purpose.

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