• International Journal of Stem Cells
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• 제9권2호
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• pp.186-191
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• 2016

Background and Objectives: With the global demand for dairy protein for consumption growing annually, there has been increasing activity in the research field of dairy protein synthesis and production. From a manipulation perspective, it is more difficult to use live cattle for laboratory studies on the production of milk as well as of dairy protein such as casein, as compared with using laboratory animals like rodents. Therefore, we aimed to develop a mouse model of bovine mammary alveolar ducts for laboratory-scale studies. We studied the formation of the bovine mammary gland ductal structure by transplanting the MAC-T bovine alveolar cell line into mice. Methods and Results: MAC-T cells ($1{\times}10^7$) were suspended in Matrigel and injected into the dorsal tissue of 8-week-old male BALB/C nude mice. Histological analysis of tissue dissected from the MAC-T cell-transplanted mice after 6 weeks showed the typical morphology of the tubuloalveolar female gland, as well as glands made up of branching ducts that were surrounded by smooth muscle with small alveoli budding off the ducts. In addition, the epithelial markers CK14 and CK18 were expressed within the duct-like structure. Prolactin was detected in the duct interior in these CK14+ and CK18+ cells but not in the non-transplanted MAC-T cells. Conclusions: These results showed that duct-like tissue had been successfully formed after 6 weeks of transplantation of the CK14+ and CK18+ MAC-T cells into mice dorsal tissue. This mouse model will be a useful tool for further research on the bovine mammary gland.

• 한국초등과학교육학회지:초등과학교육
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• 제40권3호
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• pp.326-342
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• 2021

본 연구에서는 컴퓨팅 사고의 핵심인 알고리즘 표현을 실험 활동에 적용할 수 있도록 교사를 위한 실험 안내 자료를 개발하였다. 텍스트로 제시된 실험 매뉴얼을 순서도 기호를 사용하여 정보 시각화 프로세스에 따라 직선형, 분기형, 반복형 구조의 알고리즘 형태로 변환하였다. 그 예시로, 자석의 성질을 알아보는 실험을 알고리즘 표현을 적용하여 실험 안내 자료를 개발하였다. 개발된 실험 안내 자료는 정보의 적합성과 판단 여부가 표현된 분기 및 반복의 알고리즘 구조를 가지고 있다는 점과 실험 과정을 시각화하여 표현했다는 측면에서 기존의 순차적으로 표현된 실험 안내 자료와 차이가 있다. 본 연구에서 개발된 실험 안내 자료는 교사들의 알고리즘 사고에 대한 이해와 이를 적용한 실험 실행에 도움을 줄 수 있을 것이라 기대된다.

• Korean Circulation Journal
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• 제48권12호
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• pp.1081-1096
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• 2018

We reviewed the anatomical characteristics of the conduction system in the ventricles of human and ungulate hearts and then raised some questions to be answered by clinical and anatomical studies in the future. The ventricular conduction system is a 3-dimensional structure as compared to the 2-dimensional character of the atrial conduction system. The proximal part consisting of the atrioventricular node, the bundle of His and fascicles are groups of conducting cells surrounded by fibrous connective tissue so as to insulate from the underlying myocardium. Their location and morphological characters are well established. The bundle of His is a cord like structure but the left and right fascicles are broad at the proximal and branching at the distal part. The more distal part of fascicles and Purkinje system are linear networks of conducting cells at the immediate subendocardium but the intra-mural network is detected at the inner half of the ventricular wall. The papillary muscle also harbors Purkinje system not in the deeper part. It is hard to recognize histologically in human hearts but conducting cells as well as Purkinje cells are easily recognized in ungulate hearts. Further observation on human and ungulate hearts with myocardial infarct, we could find preserved Purkinje system at the subendocardium in contrast to the damaged system at the deeper myocardium. Further studies are necessary on the anatomical characteristics of this peripheral conduction system so as to correlate the clinical data on hearts with ventricular arrhythmias.

• 대한건축학회논문집:계획계
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• 제35권7호
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• pp.63-72
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• 2019

The purpose of this study is to apply the types of urban street pattern and the shape of streets to the master plan of a religious community complexes. The street pattern is a framework of urban structure and to understand the urban structure is helpful to understand the nature of urban streets. By analysing the precedent researches, the types of street patterns are classified as a serial pattern, a branching pattern, a grid pattern and a web pattern. The street patterns are hierarchically composed and classified as a differential development and sequential development. There are boundaries and gates where the street space is differentiated to the more private level. The urban streets continue to the architectural streets such as arcades, deck streets, corridors, lobbies and halls. The purposes and results of the master plan of this religious community complexes are as follows. 1) The school area, housing area and service area are properly separated and connected. They are separated by the building masses and connected by the street space in between. 2) The street pattern of this complexes is a serial pattern where the streets are the center of each functional building groups. The entry square is divided by the symbolic building. The one branch is school street and the other is living street. These streets are combined again to the festival street. 3) The architectural streets are organically related to the urban streets. 4) Each street spaces are of adequate form according to its properties as a place. 5) There are boundaries or gates such as a gab between buildings, posts, arches and deck streets according to the relationship between streets.

• 한국작물학회지
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• 제52권4호
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• pp.421-428
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• 2007

8품종의 쌀을 시료로 하여 전분분자의 미세구조 및 전분입자 막 조성 탄수화물의 특성과 식미치와의 상관을 분석함으로써 밥맛에 영향을 미치는 탄수화물 성분 특성에 대해서 검토한 결과는 다음과 같다. 1. 본 연구에 사용한 8품종 가운데 식미치는 고품벼가 가장 높았다. 2. 아밀로그램상의 호화특성에도 유의미한 차이가 있었는데, 최고 점도(Peak viscosity)와 강하 점도(breakdown)는 히토메보레가 가장 높았고, 미향벼가 가장 낮았다. 그러나 이들 아밀로그램상의 호화특성과 식미치와는 아무런 상관이 없었다. 3. 전분분자 중의 아밀로오스 함량은 품종 간에 유의미한 차이가 있었고, 토요식미기에 의해서 분석된 아밀로오스 함량과도 차이가 있었다. 그러나 아밀로오스 분자의 구조적인 특성과 식미치 간에는 상관이 없었다. 4. 아밀로펙틴의 미세구조 중 B/A의 값이 가장 큰 품종은 새추청벼였고, 가장 작은 품종은 팔공벼였다. 그러나 이들 수치와 식미치와는 상관이 인정되지 않았다. 5. DSC에 의한 전분입자의 호화특성도 품종 간에 차이가 있었으며, 특히 호화엔탈피는 품종 간 차이가 크게 나타났다. 그러나 호화엔탈피 역시 식미치와는 상관이 없었다. 6. 쌀 배유전분분획의 헤미셀룰로오스성 다당을 구성하고 있는 단당류는 rhamnose, fucose, ribose, arabinose, xylose 등이었으며, 총 단당류 함량은 새추청벼가 가장 높았고, 팔공벼가 가장 낮았다. 그러나 팔공벼를 제외한 양질미에서는 식미치와 상관이 없는 것을 알 수 있었다.

• 생명과학회지
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• 제24권6호
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• pp.626-632
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• 2014

한국산 붉바리 집단에서 유전적 구조와 계통 유연관계를 mtDNA COI 유전자 서열의 다형성을 이용하여 조사하였다. COI 유전자 서열을 결정하였고 기존에 보고된 서열들과 비교하였다. 본 연구를 통해 결정된 COI 서열들은 기존에 보고된 EF607565에 대하여 99.1-99.8%의 동일성을 나타내었다. 전체 20가지의 haplotype들이 발견되었고, 한국산 붉바리 집단은 19가지의 haplotype을 나타내었다. 이들 중 Hap_03과 Hap_08은 각각 제주도와 중국-특이적인 COI 서열들을 보였다. 반면, Hap_07은 한국에서 채집된 시료들과 홍콩과 대만에서 보고된 기록 등 여러 COI 서열들을 포함하였다. COI haplotype들의 다형성에 근거한 계통 유전학적 분석을 통해 작성된 NJ tree는 Epinephelus 속 내에서 단계통적인 분지양상을 나타내었고, 이는 붉바리 집단들이 공통의 모계 선조에서 진화한 것임을 나타내었다. 또한 중국해에서 보고된 COI 서열만을 포함하였던 Hap_08은 NJ tree의 중앙부에서 위치하였고, Hap_07의 서열들과도 근연의 관계임을 보여주었다. 이 결과는 중국산 붉바리 역시 동아시아의 다른 집단들과 모계적으로 연관되어있음을 보여주었다. 결과적으로, 동아시아 붉바리 집단들은 모계적으로 연관되어있을 뿐만 아니라 공통의 진화 역사를 공유하고 있으며 여전히 동아시아 해류(Kuroshio 해류)에 의해 영향을 받는 집단이라고 할 수 있다. 본 연구는 붉바리의 유전적 구조와 계통 유연관계를 이해하는 데 도움을 줄 수 있으며, 인공증식과 산업화에 관련된 연구에 있어 중요한 역할을 담당할 것으로 기대된다.

• International Journal of Naval Architecture and Ocean Engineering
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• 제10권3호
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• pp.393-402
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• 2018

While interacting with a sloping structure, an ice floe may fracture in different patterns. For example, it can be local bending failure or global splitting failure depending on the contact properties, geometry and confinement of the ice floe. Modelling these different fracture patterns as a natural outcome of numerical simulations is rather challenging. This is mainly because the effects of crack propagation, crack branching, multi fracturing modes and eventual fragmentation within a solid material are still questions to be answered by the on-going research in the Computational Mechanic community. In order to simulate the fracturing of ice floes with arbitrary geometries and confinement; and also to simulate the fracturing events at such a large scale yet with sufficient efficiency, we propose a semi-analytical/empirical and semi-numerical approach; but with focus on the global splitting failure mode in this paper. The simulation method is validated against data we collected during the Oden Arctic Technology Research Cruise 2015 (OATRC2015). The data include: 1) camera images based on which we specify the exact geometry of ice floes before and after an impact and fracturing event; 2) IMU data based on which the global dynamic force encountered by the icebreaker is extracted for the impact event. It was found that this method presents reasonably accurate results and realistic fracturing patterns upon given ice floes.

• IMMUNE NETWORK
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• 제3권2호
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• pp.156-163
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• 2003

Background: $\beta$-1,3-glucans are well known to enhance the immune reactions, resulting in antitumor, antibacterial, antiviral, anticoagulatory and wound healing activities. $\beta$-1, 3-glucans have various activities depending on molecular weight, degree of branching, conformation, water-solubility and intermolecular association. However, the $\beta$-1,3-glucan linked backbone structure is essential and $\beta$-D-glucopyranosyl units are required for immuno-potentiating activities. Result: In this study, we tested the immunophamacological activities of soluble $\beta$-1,3-glucans and confirmed the following activities: (1) $IFN-{\gamma}$ production in PBMCs in the presence or the absence of PHA, LPS, or IL-18; (2) induction of various cytokines in the spleen and thymus; (3) adjuvant effect on the antibody production; (4) nitrogen oxide synthesis in macrophages; (5) the cytotoxic and antitumor effects on cell lines and ICR mice. Conclusion: These results strongly suggested that $\beta$-1,3-glucans possessed various immuno-pharmacological activities.

• Journal of Plant Biotechnology
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• 제36권3호
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• pp.207-213
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• 2009

Starch serves not only as an energy source for plants, animals, and humans but also as an environmentally friendly alternative for fossil fuels. Progress in understanding of starch biosynthesis, and the isolation of many genes involved in this process have enabled the genetic modification of crops in a rational manner to produce novel starches with improved functionality. Starch is composed of two glucose polymers, amylose and amylopectin. The amylose and amylopectin ratio in starch affects its physical and physicochemical properties. Alteration in starch structure can be achieved by modifying genes encoding the enzymes responsible for starch biosynthesis and starch hydrolysis. Here, we describe recent findings concerning the starch modification in sweetpotato. Sweetpotato [Ipomoea batatas (L.) Lam] ranks seventh in annual production among food crops in the world as an important starch source. To develop transgenic sweetpotato plants with modifying starch composition, we constructed transformation vectors overexpressing granule bound starch synthase I and inhibiting amylopectin synthesis genes such as starch branching enzyme and isoamylase under the control of 35S promoter, respectively. Transformation of sweetpotato (cv. Yulmi) is in progress.

• Journal of Microbiology and Biotechnology
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• 제12권4호
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• pp.603-609
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• 2002

DFA IV is di-D-fructose-2,6':6,2'-dianhydride, consisting of two fructose residues. It can be enzymatically synthesized from levan by levan fructotransferase, and can be used for mineral absorption. Understanding of the structure and composition of levan is important to obtain high-level production of DFA IV. A bacterial strain, Pseudomonas aurantiaca 5-4380, was identified to produce low-branched levan, and the levansucrase gene (lsch) from this bacterium was found to be composed of 1,275 Up coding for a protein of 424 amino acids, with an estimated molecular weight of 47 kDa. The bacterial levansucrase gene was expressed in Escherichia coli DH5${\alpha}$ by its own promoter and lac promoter. The recombinant levansucrase was produced in soluble form with 170U of levansucrase activity from 1-ml E. coii culture broth. The expressed enzyme from the clone showed similar biochemical properties, such as size of active levansucrase, degree of branching, and optimum temperature, with P.aurantiaca 5-4380 levansucrase.