• Molecules and Cells
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• v.38 no.3
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• pp.195-201
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• 2015

Antibodies are powerful defense tools against pathogens but may cause autoimmune diseases when erroneously directed toward self-antigens. Thus, antibody producing cells are carefully selected, refined, and expanded in a highly regulated microenvironment (germinal center) in the peripheral lymphoid organs. A subset of T cells termed T follicular helper cells (Tfh) play a central role in instructing B cells to form a repertoire of antibody producing cells that provide life-long supply of high affinity, pathogenspecific antibodies. Therefore, understanding how Tfh cells arise and how they facilitate B cell selection and differentiation during germinal center reaction is critical to improve vaccines and better treat autoimmune diseases. In this review, I will summarise recent findings on molecular and cellular mechanisms underlying Tfh generation and function with an emphasis on T cell costimulation.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.5 no.5
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• pp.999-1012
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• 2011

This paper proposes an algorithm that enables mobile nodes to implement self-regulated movements in mobile ad-hoc networks (MANETs). It is important for mobile nodes to maintain a certain level of network-based stability by harmonizing these nodes' movements autonomously due to their limited transmission range and dynamic topology. Entropy methods based on relative position are suggested, as a means for mobile nodes to regulate their local movements. Simulations show that an early warning mechanism is suitable to maintain movement-based stability. Isolation can be reduced by 99%, with an increased network cost of 12% higher power consumption, using the proposed algorithm.

• Journal of Engineering Education Research
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• v.15 no.6
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• pp.49-57
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• 2012

This paper deals with the individual homework creating and management system. The proposed system can be applied to various types of homeworks such as problem solving, experiment and watching some video material related to lecture. Every authorized student can connect the web server in which the proposed system is implemented and download his assignment which is different from other student's. Also we provide real application examples to show the feasibility and effectiveness of the proposed system regarding 3 types of assignments and expect to help the students to do self-regulated study and improve their professional capability.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.213-214
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• 2017

This study was conducted to analyze the relevant of the self-regulated learning capability and learning effectiveness based on the type of e-learning contents and learner's preference, academic achievement according to enhancement of K-MOOC. The results of this study will present the effectiveness of e-learning contents type, and expect to suggest to develop effective contents type for various courses.

• Molecules and Cells
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• v.37 no.4
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• pp.337-344
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• 2014

Adipose-derived stem cells represent a type of mesenchymal stem cells with the attendant capacity to self-renew and differentiate into multiple cell lineages. We have performed a microarray-based gene expression profiling of osteogenic differentiation and found that the transcription factor Sox11 is down-regulated during the process. Functional assays demonstrate that down-regulation of Sox11 is required for an efficient differentiation. Furthermore, results from forced expression of constitutively-active and dominant-negative derivatives of Sox11 indicate that Sox11 functions as a transcriptional activator in inhibiting osteogenesis. Sox11 thus represents a novel regulator of osteogenesis whose expression and activity can be potentially manipulated for controlled differentiation.

• Journal of Korea Technology Innovation Society
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• v.7 no.3
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• pp.581-606
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• 2004

Korean Innovation Systems are in transition from catch-up regime to post catch-up regime. This paper tries to analyse the change of scientific and technological practices in the public sector of Korea Innovation Systems. This paper focus on the way public sector scientific and technological practices are regulated and contribute to private sector. It is argued that self-governing practice of public S&T community is being enhanced and the requests of private sector for the public sector's contribution through research activity are reinforced in emerging post catch-up regime.

• Molecules and Cells
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• v.40 no.5
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• pp.322-330
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• 2017

This study investigated the role of cancer/testis antigen DDX53 in regulating cancer stem cell-like properties. DDX53 shows co-expression with CD133, a marker for cancer stem cells. DDX53 directly regulates the SOX-2 expression in anti-cancer drug-resistant $Malme3M^R$ cells. DDX53 and miR-200b were found to be involved in the regulation of tumor spheroid forming potential of Malme3M and $Malme3M^R$ cells. Furthermore, the self-renewal activity and the tumorigenic potential of $Malme3M^R$-CD133 (+) cells were also regulated by DDX53. A miR-200b inhibitor induced the direct regulation of SOX-2 by DDX53 We therefore, conclude that DDX53 may serve as an immunotherapeutic target for regulating cancer stem-like properties of melanomas.

• Educational Technology International
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• v.24 no.1
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• pp.81-114
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• 2023

The study aimed to qualitatively examine middle school students' engagement in distance instruction during the COVID-19 pandemic. The participants comprised 119 students from a girls' middle school in Seoul, South Korea. To gain an in-depth understanding of the students' experiences, we collected their reflective journals, which included structured items about their learning engagement at three timepoints in 2020: April, July, and December. The following are the results: 10 themes and 18 concepts were derived, and they were integrated into causal conditions (sudden transition due to COVID-19), contextual condition (technology readiness, school education context), central phenomena (high level of behavioral engagement, low emotional engagement), interventional conditions (recognizing the potential of online learning, situational awareness about COVID-19 and online learning), action/interaction phenomena (development and use of self-regulated learning strategies), and consequences (changes in practices and perception towards online learning). Based on the findings, engagement patterns of the participants were classified into five types: proactive, conservative, receptive, reactive, passive learners. The present study demonstrated important findings that are essential for the improvement and development of engaging online learning strategies in the future.

• Journal of Gifted/Talented Education
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• v.26 no.2
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• pp.365-387
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• 2016

This study examined the effects of students'perceptions of classroom on self-regulatory strategy use, persistent intention, and achievement in an online Science gifted program. The sample included 434 middle and high school students who participated in the 3-months online gifted program. Participants volunteerly surveyed on their perceptions of classroom (appeal, challenge, choice, meaningfulness, academic self-efficacy), self-regulatory strategy use, and persistent intention. Student achievement data was collected from online learning system. Multiple Regression was conducted to analyze the effect of students'perceptions of classroom on various dependent variables. The results of this study showed that (1) students use of rehearsal strategy was positively related to academic self-efficacy among the sub-variables of students'perceptions of classroom and the use of rehearsal strategy was negatively related to challenge; (2) the use of elaboration strategy was positively related to challenge and meaningfulness; (3) the use of time management strategy was positively related to academic self-efficacy and the use of resource management strategy was positively related to challenge; and (4) students' persistent intention was related to appeal, challenge and meaningfulness, achievement was related to challenge.

• Journal of Environmental Science International
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• v.24 no.2
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• pp.175-188
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• 2015

For 63 soil series distributed in Jeju Island, natural uncultivated soils in each soil series were collected, and their physicochemical properties and their concentrations of 19 heavy metals including 8 heavy metals which are regulated by Korean Soil Environment Conservation Law, were analyzed. Moreover, the correlations between physicochemical properties and heavy metal concentrations, and between heavy metal concentrations were analyzed. The heavy metals distributed in the higher concentrations and the lower concentrations with arithmetric mean value, were Mn(730 mg/kg) and Ba(493 mg/kg), and Hg(0.146 mg/kg) and Tl(0.096 mg/kg), respectively. The correlations between pH($H_2O$) and heavy metals(Hg, Ni, Co, Se), between pH(NaF) and heavy metals(Hg, Ba, Se, Tl), and between organic matter content and heavy metals(Hg, Tl) were significant at the 0.01 level. From the correlations between heavy metal concentrations, there were 22 where there were significant at the 0.01 level and they showed positive correlation. Among those, the heavy metals showing the correlation higher than r=0.5, were Sb-V(0.878), Mo-Sn(0.867), Co-V(0.654), Co-Sb(0.648), Be-Sn(0.546), and Sn-Tl(0.528).