• 대한화학회지
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• 제31권4호
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• pp.295-300
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• 1987

고분자전해질인 Chondroitin sulfate A(CSA) 및 Chondroitin sulfate C(CSC) 존재하에서의 methylene blue(MB) 및 acridine orange(AO)의 metachromasy 현상에 관하여 각각 분광학적 방법으로 연구하였다. P/D값의 변화에 따르는 meta-band의 특성적 변화를 stacking 이론에 의하여 설명하였으며, staking 효과의 정량적 고찰에 의하여 고분자의 반복단위당 결합하는 색소분자의 수를 계산한 결과 MB가 AO보다 강한 stacking 효과를 나타냄이 발견되었다. CAS의 안정한 형태의 골격구조와 dimension을 발견하고 평면 방향색소의 free dimer의 모형을 근거로 CSA의 골격표면에 결합한 색소분자의 stacking모형과 dimension을 제안하였다.

• Computational Structural Engineering : An International Journal
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• 제1권2호
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• pp.97-106
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• 2001

Safety and serviceability of a planar steel frame are assessed. Attention is turned to the individual main steps in the assessment procedure, i.e., to the definition of loads, selection of transformation model, determination of the response of the structure to the loading, and to the definition of the limiting values (considering safely and serviceability of the structure). The potential of the method using direct Monte Carlo technique as a powerful tool is emphasized.

• Journal of Yeungnam Medical Science
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• 제32권1호
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• pp.1-7
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• 2015

Over several decades, a hierarchical cancer stem cell (CSC) model has been established in development of solid cancers, including hepatocellular carcinoma(HCC). In terms of this concept, HCCs originate from liver CSCs. Clinically HCCs show a wide range of manifestations from slow growth to very aggressive metastasis. One of the reasons may be that liver CSCs originate from different cells. This review describes the basic concept of CSCs and the cellular origin of liver CSCs.

• Molecules and Cells
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• 제27권4호
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• pp.491-492
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• 2009

We present the result of our research on the tumorigenic ability of single cell clones isolated from an aggressive murine breast cancer cell line in a matched allografting mouse model. Tumor formation is basically dependent on the cell numbers injected per location. We argue that in vivo tumor formation from single cell clones, isolated in vitro from cancer cell lines, may not provide conclusive evidence to disprove the cancer stem cell (CSC) theory without additional data.

• Computers and Concrete
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• 제20권1호
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• pp.1-10
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• 2017

This paper focuses on the mesh-size dependency in numerical simulations of reinforced concrete (RC) structures subjected to blast loading. A tensile failure criterion that can minimize the mesh-dependency of simulation results is introduced based on the fracture energy theory. In addition, conventional plasticity based damage models for concrete such as the CSC model and the HJC model, which are widely used for blast analyses of concrete structures, are compared with the orthotropic model that adopts the introduced tensile failure criterion in blast tests to verify the proposed criterion. The numerical predictions of the time-displacement relations at the mid-span of RC beams subjected to blast loading are compared with experimental results. The analytical results show that the numerical error according to the change in the finite element mesh size is substantially reduced and the accuracy of the numerical results is improved by applying a unique failure strain value determined by the proposed criterion.

• BMB Reports
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• 제48권2호
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• pp.68-80
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• 2015

G protein-coupled receptors (GPCRs) are a large class of transmembrane receptors categorized into five distinct families: rhodopsin, secretin, adhesion, glutamate, and frizzled. They bind and regulate 80% of all hormones and account for 20-50% of the pharmaceuticals currently on the market. Hundreds of GPCRs integrate and coordinate the functions of individual cells, mediating signaling between various organs. GPCRs are crucial players in tumor progression, adipogenesis, and inflammation. Several studies have also confirmed their central roles in embryonic development and stem cell maintenance. Recently, GPCRs have emerged as key players in the regulation of cell survival, proliferation, migration, and self-renewal in pluripotent (PSCs) and cancer stem cells (CSCs). Our study and other reports have revealed that the expression of many GPCRs is modulated during the generation of induced PSCs (iPSCs) or CSCs as well as during CSC sphere formation. These GPCRs may have crucial roles in the regulation of self-renewal and other biological properties of iPSCs and CSCs. This review addresses the current understanding of the role of GPCRs in stem cell maintenance and somatic reprogramming to PSCs or CSCs.

• Natural Product Sciences
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• 제23권1호
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• pp.35-39
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• 2017

D-chiro-inositol (DCI) is a secondary messenger in insulin signal transduction. It is produced in vivo from myo-inositol via action of epimerase. In this study, we evaluated antitumor activity of DCI against human breast cancer both in vitro and in vivo. In order to determine the inhibitory effects of DCI on growth of human breast cancer cells (MDA-MB-231), two different assessment methods were implemented: MTT assay and mouse xenograft assay. MTT assay demonstrated downturn in cell proliferation by DCI treatment (1, 5, 10, 20 and 40 mM) groups by 18.3% (p < 0.05), 17.2% (p < 0.05), 17.5% (p < 0.05), 18.4% (p < 0.05), and 24.9% (p < 0.01), respectively. Also, inhibition of tumor growth was investigated in mouse xenograft model. DCI was administered orally at the dose of 500 mg/kg and 1000 mg/kg body weight to treat nude mouse for 45 consecutive days. On the 45th day, tumor growth of DCI (500 mg/kg and 1000 mg/kg) groups was suppressed by 22.1% and 67.6% as mean tumor volumes were $9313.8{\pm}474.1mm^3$ and $3879.1{\pm}1044.1mm^3$, respectively. Furthermore, breast cancer stem cell (CSC) phenotype ($CD44^+/C24^-$) was measured using flow cytometry. On the 46th day, CSC ratios of DCI (500 mg/kg) and co-treatment with doxorubicin (4 mg/kg) and DCI (500 mg/kg) group decreased by 24.7% and 53.9% (p < 0.01), respectively. Finally, from tumor recurrence assay, delay of 5 days in the co-treatment group compared to doxorubicin (4 mg/kg) alone group was observed. Based on these findings, we propose that DCI holds potential as an anti-cancer drug for treatment of breast cancer.

• Steel and Composite Structures
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• 제27권1호
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• pp.123-133
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• 2018

Steel-concrete-steel (SCS) sandwich composite structure with corrugated-strip connectors (CSC) has the potential to be used in buildings and offshore structures. In this structure, CSCs are used to bond steel face plates and concrete. To overcome executive problems, in the proposed system by the authors, shear connectors are one end welded as double skin composites. Hence, this system double skin with corrugated-strip connectors (DSCS) is named. In this paper, finite element model (FEM) of push-out test was presented for the basic component of DSCS. ABAQUS/Explicit solver in ABAQUS was used due to the geometrical complexity of the model, especially in the interaction of the shear connectors with concrete. In order that the explicit analysis has a quasi-static behavior with a proper approximation, the kinetic energy (ALLKE) did not exceed 5% to 10% of the internal energy (ALLIE) using mass-scaling. The FE analysis (FEA) was validated against those from the push-out tests in the previous work of the authors published in this journal. By comparing load-slip curves and failure modes, FEMs with suitable analysis speed were consistent with test results.

• 응용통계연구
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• 제18권3호
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• pp.701-712
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• 2005

로지스틱 회귀모형에서 suppression의 논의는 선형회귀의 논의보다 많지 않은데 그 이유 중의 하나는 회귀제곱합 또는 결정계수의 정의가 유일하지 않고 다양하기 때문이다. 여러 종류의 결정계수들 중에서 선호되는 두 종류의 결정계수와 Liao와 McGee(2003)가 제안한 두 종류의 수정 결정계수의 정의로부터 회귀제곱합을 유도하여 로지스틱 회귀모형에서의 suppression을 설명하고자 한다. 모의실험을 통하여 자료를 생성하여 어떤 경우에 suppression이 발생하는지를 살펴보고 그 결과를 선형회귀모형에서의 suppression 결과와 비교한다.

• 한국정보처리학회논문지
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• 제7권10호
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• pp.3075-3085
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• 2000

소프트웨어 개발과 운영이 분산화, 대형화됨에 따라 정확하고 완전한 요구사항의 추출과 명세는 시스템의 가장 중요한 요소가 되고 있다. 또한 인터넷을 통한 공동작업 환경에서 계속적인 시스템 변경요청은 더욱 효율적인 요구사항 관리를 필요로 한다. 본 논문에서는 이러한 공동작업 환경에서 자연어 기반 요구사항 명세와 관리의 효율성을 향상시키기 위한 요구사항 명세구조와 기법 등을 정의하고, 요구공학 활동과 주기를 바탕으로 하는 요구공학 프로세서와 환경을 제안한다. 그래서 CSCW(Computer Supported Cooperative Work) 환경에서 요구사항을 정확하게 추출하고 효율적으로 관리하며 분석단계로 자연스러운 전이가 가능하도록 한다.