• BMB Reports
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• 제35권1호
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• pp.87-93
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• 2002

Neural cell survival is an essential concern in the aging brain and many diseases of the central nervous system. Neural transplantation of the stem cells are already applied to clinical trials for many degenerative neurological diseases, including Huntington's disease, Parkinson's disease, and strokes. A critical problem of the neural transplantation is how to reduce their apoptosis and improve cell survival. Neurotrophic factors generally contribute as extrinsic cues to promote cell survival of specific neurons in the developing mammalian brains, but the survival factor for neural stem cell is poorly defined. To understand the mechanism controlling stem cell death and improve cell survival of the transplanted stem cells, we investigated the effect of plausible neurotrophic factors on stem cell survival. The neural stem cell, HiB5, when treated with PDGF prior to transplantation, survived better than cells without PDGF. The resulting survival rate was two fold for four weeks and up to three fold for twelve weeks. When transplanted into dorsal hippocampus, they migrated along hippocampal alveus and integrated into pyramidal cell layers and dentate granule cell layers in an inside out sequence, which is perhaps the endogenous pathway that is similar to that in embryonic neurogenesis. Promotion of the long term-survival and differentiation of the transplanted neural precursors by PDGF may facilitate regeneration in the aging adult brain and probably in the injury sites of the brain.

• 한국지구과학회지
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• 제40권4호
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• pp.436-445
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• 2019

This study presents how two types of integrated science and engineering lessons affect students' engineering problem solving skills and their perceptions of engineering. In total, 146 middle school students participated in this study. Eighty-six students participated in the Type I lesson (complete engineering design lesson with a science knowledge application) and 60 students participated in the Type II lesson (engineering design without a science knowledge application). Two main datasets, (1) students' Creative Engineering Problem Solving Propensity (CEPSP) measurement scores and (2) open-ended survey questions about students' perceptions of engineering, were collected before and after the lessons. The results of this study show that after participating in the Type I lesson, students' CEPSP scores significantly increased, whereas the CEPSP scores of the students who participated in the Type II lesson did not increase significantly. In addition, students who participated in the Type I lesson perceived engineering and the engineering integrated science lesson differently compared to the students who participated in the Type II lesson. The results of this study show that engineering integrated science, technology, engineering & mathematics (STEM) lessons should include a complete engineering design and a science knowledge application to improve students' engineering problem solving skills.

• International Journal of Advanced Culture Technology
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• 제8권3호
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• pp.280-284
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• 2020

In the rapidly changing science and technology environment, an in-depth understanding of users of STEM information is an essential factor in designing a user-centered information system. The purpose of this study is to investigate and analyze in-depth the behaviors and needs of users who use STEM information. In this study, the needs of users for STEM information and STEM information sites are dealt with in depth using the FGI qualitative method. In addition, it includes the analysis results of grouping of similar sites according to various aspects of use of STEM information sites. As a result of grouping similar sites based on awareness and level of use,, they were grouped by domestic-international, paid-free, integrated-specific fields. As a result of grouping similar sites according to the purpose of use, they were grouped by domestic and international papers, research reports, and patents. As a result of grouping similar sites according to usage attributes, they were grouped by diversity, reliability, and specialization. As for the positions of similar sites perceived by users, Science Direct and PubMed showed high specialization and high quality, Google Scholar showed integration and popularity, and RISS showed four attributes evenly. Suggestions for information system design are discussed.

• STI Policy Review
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• 제1권2호
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• pp.1-18
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• 2010

The development and maintenance of human capacity in economies is critical to long term competitiveness, but also for the overall health and environment of regions. Yet, human science and technology-based capacity is multidimensional and has interrelated characteristics which present certain policy challenges. This paper addresses a range of issues specific to a discussion on human capacity in S&T. First, the paper emphasizes the importance of acknowledging the complexity of human capacity issues and how they evolve along the STEM (science, technology, engineering, and mathematics) pipeline. The pipeline is an often used reference to describe the training and development in STEM disciplines, from early childhood education, to more advanced training, and finally to professional collaboration and interaction and serves as a useful organizing framework for the discussion of capacity along the career evolution process. Second, the paper offers an organizing framework for discussion of policy mechanisms that have been developed to address issues and gaps that occur along this STEM pipeline. Specifically, it contrasts the traditional mechanisms of building human capacity in STEM areas with newer "gap filling" and integrated approached to addressed human capacity disparities and priorities. Third, the paper addresses core challenges in human capacity in STEM, including the education and training, participation of women and underrepresented groups, brain drain/brain circulation issues, and the globalization of science. The paper concludes with a discussion of policy implication for the development of human capacity.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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• pp.223.2-223.2
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• 2015

Polyurethane acrylate (PUA) has been introduced to utilize as a mold material for sub-100 nm lithography as it provides advantages of stiffness for nanostructure formation, short curing time, flexibility for large area replication and transparency for relevant biomedical applications. Due to the ability to fabricate nanostructures on PUA, there have been many efforts to mimic extracellular matrix (ECM) using PUA especially in a field of tissue engineering. It has been demonstrated that PUA is useful for investigating the nanoscale-topographical effects on cell behavior in vitro such as cell attachment, spreading on a substrate, proliferation, and stem cell fate with various types of nanostructures. In this study, we have conducted surface modification of PUA films with micro/nanostructures on their surfaces using plasma treatment. In general, it is widely known that the plasma treated surface increases cell attachment as well as adsorption of ECM materials such as fibronectin, collagen and gelatin. Effect of plasma treatment on PUA especially with surface of micro/nanostructures needs to be understood further for its biomedical applications. We have evaluated the modified PUA film as a culture platform using adipose derived stem cells. Then, the behavior of stem cells and the level of adsorbed protein have been analyzed.

• 한국지구과학회지
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• 제36권5호
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• pp.484-499
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• 2015

This study explores the impact of a STEM integration teacher professional development program focusing on teachers' perception of engineering and their attitudes toward integrating engineering into teaching. A total of sixty-eight teachers from ten schools participated in the program for five days. Data are collected from three main sources including (1) pre and post concept maps probing teachers' perceptions about the engineering discipline, (2) a pre and post survey measuring teachers' self-efficacy of teaching science/mathematics within the engineering context, and (3) engineering integrated science and (or) mathematics lesson plans and teaching reflections. This study utilizes both qualitative and quantitative research methods depending on the data we have collected. The results show that both science and math teachers thought that integrating engineering into teaching provided valuable outcomes, i.e., promoting students' learning about engineering and improving their interest in science or math through real-world problem solving exercises. Participants also felt more comfortable about integrating engineering in their teaching after the program. The results also imply that the teachers' understandings of engineering become more concrete after the program. This study also provides an overview of the challenges and advantages of teaching engineering in K-12 science and mathematics classrooms.

• 한국과학교육학회지
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• 제34권2호
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• pp.63-78
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• 2014

통합적 STEM 교육은 과학, 기술, 공학, 수학의 내용과 과정을 체계적이고 의도적으로 통합하려는 공학적 설계기반 학습을 말하며, 다른 교과와 통합을 통해 더욱 발달할 수 있다. 이 연구는 과학 탐구 기반의 통합적 STEM 교육 프로그램의 개발과 효과 검증을 위한 기초연구이며, STEM 교육 관련 문헌 연구를 통해 STEM 교육의 가치와 핵심요소를 분석하고 과학 탐구 기반의 통합적 STEM 교육 모형의 개발 및 모형을 적용하여 개발한 대표적인 예시 프로그램을 제시하는 것이다. 모형에 포함될 요소를 확정하기 위해 문헌 분석을 실시하였고, 선행 연구에 포함된 내용과 탐구 과정을 분석하여 통합적 STEM 교육 모형을 구성하였다. 전문가의 내용 타당도 분석 결과 CVR 값의 평균은 0.78로 구성된 모형은 내용 타당도가 있는 것으로 판단되었다. 이 STEM 교육 모형은 내용과 탐구 과정의 두 가지 측면으로 나누어진다. 내용의 측면은 실생활 문제에서 경험할 수 있는 과학, 기술, 공학, 수학 그리고 인문사회와 예술적 소재까지 포괄할 수 있으며, 탐구 과정은 설계와 제작을 기반으로 한 문제해결 과정이다. 탐구 과정은 과학 탐구를 기반으로 하여 기술 공학적 문제해결 과정을 적용할 수 있도록 구성하였다. 학생들은 실생활 문제를 분석하고, 설계하고 제작하는 과정에서 STEM 교과에 대한 흥미를 향상시킬 수 있고 문제에 포함된 지식과 탐구의 방법과 기능을 체계적으로 학습할 수 있다. 개발된 프로그램은 학교 현장에서 활용되어, STEM 교과에 대한 이해도 증진과 과학, 수학에 대한 흥미를 높이고, 과학기술 기반의 융합적 소양과 설계 기반의 문제해결력을 배양하는 데 기여할 수 있을 것이다.

• Molecules and Cells
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• 제46권4호
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• pp.209-218
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• 2023

In induced pluripotent stem cells (iPSCs), pluripotency is induced artificially by introducing the transcription factors Oct4, Sox2, Klf4, and c-Myc. When a transgene is introduced using a viral vector, the transgene may be integrated into the host genome and cause a mutation and cancer. No integration occurs when an episomal vector is used, but this method has a limitation in that remnants of the virus or vector remain in the cell, which limits the use of such iPSCs in therapeutic applications. Chemical reprogramming, which relies on treatment with small-molecule compounds to induce pluripotency, can overcome this problem. In this method, reprogramming is induced according to the gene expression pattern of extra-embryonic endoderm (XEN) cells, which are used as an intermediate stage in pluripotency induction. Therefore, iPSCs can be induced only from established XEN cells. We induced XEN cells using small molecules that modulate a signaling pathway and affect epigenetic modifications, and devised a culture method which can produce homogeneous XEN cells. At least 4 passages were required to establish morphologically homogeneous chemically induced XEN (CiXEN) cells, whose properties were similar to those of XEN cells, as revealed through cellular and molecular characterization. Chemically iPSCs derived from CiXEN cells showed characteristics similar to those of mouse embryonic stem cells. Our results show that the homogeneity of CiXEN cells is critical for the efficient induction of pluripotency by chemicals.

• 한국수학교육학회지시리즈D:수학교육연구
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• 제24권3호
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• pp.137-173
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• 2021

Research and national standards, such as the Next Generation Science Standards (NGSS) in the United States, promote the development and implementation of K-12 interdisciplinary curricula integrating the disciplines of science, technology, engineering, mathematics, and computer science (STEM+CS). However, little research has explored how teachers provide epistemic support in interdisciplinary contexts or the factors that inform teachers' epistemic support in STEM+CS activities. The goal of this paper is to articulate how interdisciplinary instruction complicates epistemic knowledge and resources needed for teachers' instructional decision-making. Toward these ends, this paper builds upon existing models of teachers' instructional decision-making in individual STEM+CS disciplines to highlight specific challenges and opportunities of interdisciplinary approaches on classroom epistemic supports. First, we offer considerations as to how teachers can provide epistemic support for students to engage in disciplinary practices across mathematics, science, engineering, and computer science. We then support these considerations using examples from our studies in elementary classrooms using integrated STEM+CS curriculum materials. We focus on an elementary school context, as elementary teachers necessarily integrate disciplines as part of their teaching practice when enacting NGSS-aligned curricula. Further, we argue that as STEM+CS interdisciplinary curricula in the form of NGSS-aligned, project-based units become more prevalent in elementary settings, careful attention and support needs to be given to help teachers not only engage their students in disciplinary practices across STEM+CS disciplines, but also to understand why and how these disciplinary practices should be used. Implications include recommendations for the design of professional learning experiences and curriculum materials.

• 생약학회지
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• 제42권2호
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• pp.161-168
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• 2011

Advanced glycation end products (AGEs) has been shown to play an important role in the development of the diabetic complications. The AGEs inhibitors or cross-link breakers attenuate various functional and structural manifestations of diabetic complications. In this study, 69 China herbal medicines have been investigated with an in vitro evaluation system using AGEs inhibitory activity. Of these, 28 herbal medicines $IC_{50}$=<50 ${\mu}g/ml$) were found to have stronger AGEs inhibitory activity compared with aminoguanidine ($IC_{50}$=59.77 ${\mu}g/ml$). Particularly, 5 herbal medicines, Camptotheca acuminata (stem, leaf), Eurya groffii (stem, leaf), Cornus Capitata (leaf), Mucuna birdwoodiana (root), Nelumbo nucifera (fruit, seed) showed more potent inhibitory activity (approximately 6-27 fold) than the positive control aminoguanidine.