• Journal of Microbiology and Biotechnology
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• 제10권6호
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• pp.844-850
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• 2000

The specific binding and internalization of viral particles is an essential step for the successful infection of viral pathogens. In the case of the hepatitis B virus (HBV), virions bind to the host cell via the preS domain of the viral surface antigen and are subsequently internalized by endocytosis. HBV-preS specific receptors are primarily expressed on hepatocytes, however, viral DNA and proteins have also been detected in extrahepatic sites, suggsting that celluar recepators for HBV may also exist on extrahepatic cells. Recently, an EBV-transformed B-cell line was identified onto which the preS region binds in a receptor-ligand specific manner. In this study, this specific interaction was further characterized, and the binding region within the preS protein was locaized. Also the internalization after host cell attachment was visualized and analyzed by fluorescence-labeled HBV-preS1 proteins using confocal microscopy. Energy depletion by sodium azide treatment effectively inhibited the internalization of the membrane-bound preS1 ligands, thereby indicating an energy-dependent receptor-mediated endocytotic pathway. Accordingly, the interaction of HBV-pres! with this specific B-cell line may serve as an effective model for an infection pathway in extrahepatic cells.

• BMB Reports
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• 제40권6호
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• pp.1002-1008
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• 2007

PreS domain of Hepatitis B virus (HBV) surface antigen is a good candidate for an effective vaccine as it activates both B and T cells besides binding to hepatocytes. This report deals with overexpression and purification of adr subtype of surface antigen that is more prevalent in Pakistan. PreS region, comprising 119 aa preS1 region plus a 55 aa preS2 region plus 11 aa from the N-terminal S region, was inserted in pET21a+ vector, cloned in E. coli $DH5\alpha$ cells and expressed in E. coli BL21 codon+ cells. The conditions for over expression were optimized using different concentrations of IPTG (0.01-5 mM), and incubating the cells at different temperatures (23-$41^{\circ}C$) for different durations (0-6 h). The cells were grown under the given optimized conditions (0.5 mM IPTG concentration at $37^{\circ}C$ for 4 h), lysed by sonication and the protein was purified by ion exchange chromatography. On the average, 24.5 mg of recombinant protein was purified per liter of culture. The purified protein was later lyophilized and stored at $-80^{\circ}C$.

• 한국지역사회생활과학회지
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• 제16권1호
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• pp.65-72
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• 2005

To increase dyeability of cotton fabric to the chestnut shell dyeing, we had several dyeing experiments with the experimental fabrics which was pre-treated by soybean, NaOH, KOH. Three kinds of experimental cotton fabrics were used and chestnut shell dyebath was made for the experiment. Munsell's color HV/C and color differences ΔE of dyeing fabrics were compared between pre-treatment and none pre-treatment dyeing fabrics. The main results were as follows ; Color differences of dyeing fabrics pre-treated with soybean, NaOH, KOH were higher than those of none pre-treated dyeing fabrics. In case of pre-treatment with soybean, the concentration of the soybean bath affected the color differences but not affected in case of pre-treatment with NaOH & KOH. Munsell's color of pre-treatment fabrics with soybean, NaOH, KOH were same with the none pre-treatment fabrics. Colorfastness of the pre-treated fabrics were same degree, but only in case of soybean pre-treated fabrics were low in fastness of washing(change) & perspiration(acidic change).

• BMB Reports
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• 제28권4호
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• pp.353-358
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• 1995

Epitope tagging is the process of fusing a set of amino acid residues that are recognized as an antigenic determinant to a protein of interest. Tagging a protein with an epitope facilitates various immunochemical analyses of the tagged protein with a specific monoclonal antibody. The monoclonal antibody H8 has subtype specificity for an epitope derived from the preS2 region of hepatitis B virus surface antigen. Previous studies on serial deletions of the preS2 region indicated that the preS2 epitope was located in amino acid residues 130~142. To test whether the amino acid sequence in this interval is sufficient to confer on proteins the antigenicity recognizable by the antibody H8, the set of amino acid residues in the interval was tagged to the amino terminal of ${\beta}$-galactosidase and to the carboxyl terminal of the truncated $p56^{lck}$ fragment. The tagged ${\beta}$-galactosidase, expressed in Escherichia coli, maintained the enzymatic activity and was immunoprecipitated efficiently with H8. The tagged $p56^{lck}$ fragment, synthesized in an in vitro translation system, was also immunoprecipitated specifically with H8. These results demonstrate that the amino acid sequence of the preS2 region can be used efficiently for the epitope tagging approach.

• 한국컴퓨터정보학회논문지
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• 제24권4호
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• pp.185-193
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• 2019

In this paper, we propose the effects of programming-based TPACK educational program on the pre-service teacher's self-efficacy beliefs for technology integration. For this study, pre-service teachers who received programming education and TPACK education based on ICT were set as control group and pre-service teachers who received programming-based TPACK education as experimental group. In order to observe the change, the pre-service teachers conducted the test tool to measure the self-efficacy beliefs for technology integration before and after applying the educational program. As a result of the study, only the pre-service teachers who received the programming-based TPACK education showed significant improvement in the self-efficacy beliefs for technology integration. Furthermore, in the post-test, the experimental group showed a significantly higher difference than the control group. Through this study, it was concluded that programming-based TPACK educational program is effective in enhancing pre-service teacher's self-efficacy beliefs for technology integration.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제7권12호
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• pp.3135-3148
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• 2013

The popularization of streaming networks and mobile devices brings a new kind of network called mobile peer-assisted streaming network. In this network, service provider not only offers downloading services, but also pre-pushes resources to users for caching. Users can download their demanded resources while working as servers for uploading the cached data. Also the mobile characteristic makes high package losing probability in this network. So we study how the service provider pre-pushes or the user downloads resources efficiently and effectively while considering the package losing in this paper. We build utility models for service provider and user, and solve the models using Bellman's theory to achieve Nash Equilibrium which shows the service provider's optimal pre-pushing speed and user's optimal downloading speed. The numerical simulation demonstrates the efficiency and effectiveness of our proposed pre-pushing and downloading scheme by comparing to the traditional scheme.

• 한국초등과학교육학회지:초등과학교육
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• 제32권1호
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• pp.82-94
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• 2013

The purpose of this study was to investigate the process and the effect of pre-service teacher's scaffolding in environmental camp program about global climate change. For this study, developed the environmental camp program based pre-service teacher's scaffolding and applied to 78 $5^{th}$ students. We analyzed the role of pre-service teacher in the process of scaffolding. In the result, the pre-service teachers conducted cognitive scaffolding like as "Focus", "Hint", "Tell or Summarize" and "Technical Help". They carried out the emotional scaffolding like as "Create Cheerful Atmosphere", "Encourage", and "Help in Living". Teaching and learning about global climate change, the theme of the camp, was regarded uncertain and complex. So, pre-service teacher's scaffolding was effective to promote environmental literacy about climate change of primary students (<0.05). The student teachers understanded the characteristics of the children through emotionally close relationships. The primary students were learned easier about global climate change through cognitive and emotional scaffolding. They experienced environmental practice with communal living in camp.

• 약학회지
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• 제45권6호
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• pp.708-714
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• 2001

Many studies have provided evidences that hepatitis B surface antigen (HBsAg) including preS region could be an ideal candidate for a new hepatitis B virus (HBV) vaccine with higher efficacy. We established CHO cell lines, IY-CHO-2 and IY-CHO-11 expressing high levels of HBsAg containing preS2 and S protein by stable transfection method. These cell lines expressed the correct size (about 1 kb in length) of HBsAg mRNA as expected. The purified protein from the culture supernatants of the clones showed the same sizes as those expressed in native hepatitis B virus (24 kDa, 27 kDa, 34 kDa and 36 kDa). Antibody productivity of CHO-derived HBsAg protein at lower dose challenge was higher than the protein containing S region alone expressed in yeast system. These results indicate that CHO-derived HBsAg protein containing preS2 and S region can be effectively used for a better immune response as a HBV vaccine.

• 한국결정성장학회지
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• 제27권6호
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• pp.295-302
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• 2017

본 연구에서는 IGCC(Integrated Gasification Combined Cycle; 석탄 가스화 복합 발전)에서 배출된 용융 슬래그(이하 용융 슬래그)를 이용한 지오폴리머의 제조 시 pre-curing 공정이 지오폴리머의 물성에 미치는 영향에 대해 연구하였다. Pre-curing이란 고온양생으로 지오폴리머를 제조하기 전에, 성형체를 상온에서 일정 시간 방치하는 공정으로서, 시편의 강도를 높이는 효과가 있다고 알려져 있다. 따라서 본 실험에서는 pre-curing 조건에 따른 지오폴리머의 압축강도 특성을 측정하였으며, SEM과 XRD로 미세구조 및 결정상 변화를 관찰하였다. W/S 비율(water/solid ratio)은 사전 실험을 통해, 성형이 가능하면서 최대 지오폴리머 강도를 확보할 수 있는 0.26으로 결정하였으며, 자극제인 알칼리 용액의 농도는 15 M로 고정하였다. 상온에서 pre-curing을 0~27일 범위 내에서 실시한 결과, pre-curing 공정을 적용한 지오폴리머의 경우, 그렇지 않은 시편에 비해 압축강도가 36~87 % 증가하는 것을 확인하였다. Pre-curing 시킨 시편에서 XRD 측정 결과, C-S-H 겔(calcium silicate hydroxide gel) 상 발현이 촉진되었고 SEM을 이용한 미세구조 관찰 결과, 부정형의 zeolite 상이 더 많이 성장된 것이 관찰되었으며 이러한 상들의 생성이 강도 증진에 영향을 미친 것으로 분석되었다.

• 한국환경교육학회지:환경교육
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• 제25권1호
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• pp.77-88
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• 2012

The purpose of this study was to analyze characteristics of environmental awareness and environmental worldviews on environmental UCCs which made by 27 pre-service biology teachers, and relationship between environmental awareness and environmental worldviews of them. Environmental worldviews were divided into planetary management worldview, stewardship worldview and environmental wisdom worldview. As for theme fo environmental UCCs, most of pre-service teachers chose themes such as environmental destruction, environmental protection, environmental conservation and coexistence with human and environment. Themes of environmental UCCs were somewhat different between females and males. Female pre-service teachers preferred UCC themes related to human's daily life as a consumer but males preferred to environmental protection. Many pre-service teachers referred that major cause of environmental problem was development of environment. Most of them had envionmental wisdom worldview, and tried to use fear appeal to express ways of solving of environmental problems and envieonmnetal worldviews. After making environmental UCCs, more pre-service teachers had envionmental wisdom worldview. This result implies that it is necessary to develop pre-service educational programs realted to environmental worldview formation.