• Title/Summary/Keyword: 방향특이성

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Synaptic Pattern of NMDA R1 upon the Direction-Selective Retinal Ganglion Cells in Developing Mouse Retina (발생 중 마우스 망막에서 방향특이성 신경절세포의 NMDA R1 수용체의 시냅스 패턴)

  • Lee, Jee-Geon;Kwon, Oh-Ju;Jeon, Chang-Jin
    • Journal of Korean Ophthalmic Optics Society
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    • v.18 no.4
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    • pp.533-540
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    • 2013
  • Purpose: To investigate the synaptic pattern of NMDA glutamate receptor subtype NMDA R1 on the dendritic arbors of ON-OFF direction-selective retinal ganglion cells (DS-RGSs) in developing [(5,10) days postnatal (PN)] mouse retina. Methods: ON-OFF DS-RGCs were injected with Lucifer yellow and the cells were identified by their characteristic morphology. To identify glutamatergic excitatory input from bipolar cell, we used a marker for the membrane traffic motor protein kinesin. Results: We identified DS-RGCs in P5, and P10 mouse retina. The immunofluorescence labeling of NMDA R1 was most prominent in the IPL. Our results showed that their presence upon the entire dendritic arbor of ON-OFF DS-RGCs is without any evidence of asymmetry, which would predict direction selectivity. Conclusions: The glutamatergic input from bipolar cell reveals symmetry pattern in all periods of P5, and P10. The results may suggest that direction selectivity not lies in the specific pattern of NMDA R1 receptors.

Molecular Structures and Catalytic Mechanism of Bacterial Lipases. (세균성 리파제의 분자구조와 작용기작)

  • 김형권
    • Microbiology and Biotechnology Letters
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    • v.31 no.4
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    • pp.311-321
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    • 2003
  • Bacteria produce lipases, which can catalyze both the hydrolysis and the synthesis of long chain triglycerides. These reactions usually proceed with high regioselectivity and enantioselectivity, and, therefore, lipases have become very important biocatalysts used in organic chemistry. 3D lipase structures were solved from several bacterial lipases. They have an $\alpha/\beta$ hydrolase fold and a catalytic triad consisting of a nucleophilic serine, and an aspartate or glutamate residue that is hydrogen bonded to a histindine. Active sites are covered with $\alpha$-helical lid structure, of which movement is involved in the enzyme's activation at oil/water interface. Four substrate binding pockets were identified for triglycerides: an oxyanion hole and three pockets accommodating the fatty acids bound at positions sn-1, sn-2, and sn-3. These pockets determine the enantiopreference of a lipase. The understanding of structure-function relationships as well as the development of molecular evolution techniques will enable researchers to tailor new lipases for biotechnological applications.

The Study on Proper Way for Engineering University Education: Based on the Perception of Current Competencies and Expected Competencies of Engineering Freshmen (공과대학 신입생의 핵심역량 인식수준을 통한 공학교육방향 연구)

  • Lee, Gyeoung-Hee;Kwon, Hyuk-Hong;Lee, Jeong-Rye;Lee, Sung-Jin
    • Journal of Engineering Education Research
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    • v.13 no.6
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    • pp.57-71
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    • 2010
  • This paper is a study on the perception of current competency and expected competency of engineering freshmen by extracting core competencies acquired from university education. It also aims to suggest proper way for engineering university education. This study extracts competencies in the following five areas as core competencies: 'knowledge on major area', 'cultural ability', 'foreign language ability', 'basic learning ability', 'intercommunication ability'. To achieve this purpose, this study surveyed 'C' university engineering department freshmen (584 students) with questionnaires about their perception of core competencies. The results are as follows. First, engineering freshmen perceived current competencies were weak in every area, especially their capacities in 'foreign language ability' area were perceived to be weakest. Their demand for education is the highest in 'foreign language ability' area, and the second higher in 'knowledge on major area'. Secondly, there exists meaningful difference between perception of current competency and expected competency depending on the gender, high school department (science/liberal arts), high school location, types of college admissions, and types of mathematics in NAST. According to these results, this study suggests enhancement of foreign language (English) education in engineering department, design and implementation of various educational program to overcome individual difference, promoting importance of competencies in the 'cultural abilty' and 'intercommunication abilty', necessity of continuous adjustment and complementation for engineering educational program through accumulation of feedback processes, activation of career education through engineering education and special programs.

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