• 제목/요약/키워드: cell movement

검색결과 429건 처리시간 0.024초

Molecular Structure of Muscle Filaments Determined by Electron Microscopy

  • Craig, Roger
    • Applied Microscopy
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    • 제47권4호
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    • pp.226-232
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    • 2017
  • Electron microscopy and X-ray diffraction have together played a key role in our understanding of the molecular structure and mechanism of contraction of muscle. This review highlights the role of electron microscopy, from early insights into thick and thin filament structure by negative staining, to studies of single myosin molecule structure, and finally to recent high-resolution structures by cryo-electron microscopy. Muscle filaments are designed for movement. Their labile structures thus present challenges to obtaining near-atomic detail, which are also discussed.

Cytoskeletal Alteration of Mammalian Oocytes During Meiotic Maturation, Fertilization and Parthenogenesis

  • 김남형
    • Clinical and Experimental Reproductive Medicine
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    • 제22권3호
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    • pp.253-258
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    • 1995
  • Microtubules and microfilaments are major cytoskeletal components in mammalian ova that provide the framework for chromosomal movement and cellular division. Extensive changes of cytoskeletal organization occur during maturation and fertilization. The changes in cytoskeletons are essential for the normal meiotic maturation and for the formation of the biparental diploid genome of the embryo, and thus are repeated at each cell cycle during embryonic development. Disturbance of the cytoskeletal organization could result in abnormal gamete development and early embryonic death.

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왕벚나무 화외밀선의 당액 분비에 관한 미세구조적 연구 (Ultrasturctural Study on Nectar Secretion from Extrafloral Nectary of Prunus yedoensis Matsumura)

  • 정병갑
    • Journal of Plant Biology
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    • 제35권2호
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    • pp.143-153
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    • 1992
  • 한국산 왕벚나무(Prunus yedoensis Matsumura) 화외밀선의 미세구조 및 당액 분비기작을 규명하기 위하여 광학현미경, 주사형 및 투과형 전자현미경을 이용하여 관찰하였다. 밀선은 secretory layer와 subsecretory layer로 구성되어 있었으며 엽병의 유관속은 subsecretory layer에 있는 유관속과 연결되어 있었다. Secretory cell에서는 cristae가 잘 발달되지 않은 다수의 mitochonidria가 관찰되었으나 소포체는 소수 나타났고 골지체가 전혀 관찰되지 않았다. 색소체는 thylakoid가 거의 발달되지 않았으며, 소수가 관찰되었고 $0.2-0.3\;\mu\textrm{m}$ 크기의 소포를 특징적으로 갖고 있었다. subsecretory cell에서는 원형질 연락사가 잘 발달해 있었고 다수의 Calcium oxalate 결정이 관찰되었는데 이는 당투과에 간접적으로 관여하는 것 같다. 당액 전구물질은 사부에서 subsecretory layer를 거쳐 secretory layer까지 이동하는 것을 원형질 연락사를 통한 symplastic transport에 의하여 일어나는 것으로 생각되며 secretory layer에서 당액으로 재합성되어 외부로 배출되는 것 같다. Secertory cell의 맨 바깥쪽 세포벽은 cuticle 에 의하여 덮여 있었으며 secretory cell에서 당액은 원형질막, 세포벽, cuticle을 차례로 통과하는 누출상 분비(eccrine secretion)에 의하여 분비되는 것으로 사료된다.

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회전익항공기용 연료셀 피탄 수치모사 연구 (Numerical Simulation of Bullet Impact for Fuel Cell of Rotorcraft)

  • 김현기;김성찬
    • 한국전산구조공학회논문집
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    • 제25권5호
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    • pp.405-411
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    • 2012
  • 회전익항공기의 연료셀 내부는 연료보관 및 연료를 엔진으로 공급하기 위한 배관과 구성품들이 배치되어 있다. 특히, 기동헬기는 전장에서 사용되는 헬기로써, 수 km 고도에서 비행하는 고정익기보다 비행고도가 낮기 때문에 피탄될 가능성이 높다. 따라서, 항공기의 생존성을 극대화하기 위해서는 피탄시 유체내부 상승압력에 의한 내부 구성품들이 받는 영향성을 검토하여 설계되어야 함은 주지의 사실이다. 그러나 내탄시험은 연료셀 자체의 제작비용 및 준비기간이 상당히 소요되고, 실탄 사용에 따른 시험수행의 제약 때문에 수치모사를 통한 관련 데이터의 확보가 필요하다. 이를 위해 본 연구에서는 유체-구조 수치모사 프로그램인 Autodyn을 이용하여 회전익항공기 연료셀의 내탄 수치모사를 수행하여, 피탄 후 연료셀 내부에서의 탄 거동을 분석하고 유체내부의 압력과 연료 셀 자체의 등가응력을 평가하였다.

태양전지를 이용한 LED 전광시스템 (LED Display System using Solar Cell)

  • 신승호;이영진;고강은;최용현;전대진;조금배
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2008년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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    • pp.251-253
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    • 2008
  • This research combines LED display System with a module of solar cell which transforms solar energy to electrical energy. In order to simplify the installation and the movement of LED Display System, the system removed the conventional power distribution is developed, and that improves the advertising effect of LED Display System.

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작업 순서와 기계 용량을 고려하는 유연조립 시스템의 독립 셀형성 (Independent Cell Formation Considering Operation Sequences and Machine Capacity in Flexible Assembly Systems)

  • 노인규;최형호
    • 산업경영시스템학회지
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    • 제19권40호
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    • pp.253-261
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    • 1996
  • In optimizing the layout design of a multi-product assembly environment, tile analysis of the material flow is a vital ingredient. In flexible assembly systems, assembly time is usually very short thus the transfer time is relatively more important Therefore operations sequence must be so determined, that have no backtracking operations as possible as, It is important to form cells, so that they have no intercell movement in curring much processing delay, and to arrange machines as possible as densly. This study presents a independent cell formation method considering operation sequences and machine capacity in flexible assembly systems.

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산업단지내 독성유기화합물 및 중금속으로 오염된 토양의 정화복원기술 상용화 연구

  • 김수곤;손규동;박지연;최희철;양지원
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2004년도 총회 및 춘계학술발표회
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    • pp.31-34
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    • 2004
  • Feasibility of electrokinetic(EK)-Fenton process and Ozone chemical oxidation were investigated for tile removal of organic contaminants and heavy metals from the contaminated soil. In EK-Fenton process, accumulated electroosmotic flow(EOF) was 80 L for 26 days. Removal efficiency of TPH, As, and Ni were 61%, 36%, and 47%, respectively. The concentration of As was high near the anode due to the transport of anionic As toward the anode, while the concentration of Ni was high near the cathode by the movement of cationic Ni to the cathode. Field scale application of in-situ ozonation was carried out for removal of TPH in 3-D test cell (3 m$\times$2 m$\times$2 m). After 25 days of ozone injection, more than 80% of removal rate was observed through the test cell.

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태양광 발전을 위한 태양추적시스템 설계 (Design of Sun Tracker System for Solar Power Generation)

  • 안준식;허남억;김일환
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2006년 학술대회 논문집 정보 및 제어부문
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    • pp.330-332
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    • 2006
  • In this paper, sun tracking system using Sun position sensor is proposed, the sun tracking system designed as which raises the efficiency of solar power generation. It design the structure being simple and it develops the system which is economical efficiency. It develops the hazard technique such as location tracking method of the sun which uses the sensor and to use the motor solar cell module movement. The Sun tracking system makes the drive in order to do with one axis and to use the sensor and to know in order to put out, the location of the sun and it makes. To make the solar location tracking sensor where the structure is simple it used two solar cells.

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Cucumber Mosaic Cucumovirus에 의한 식물의 병 - 병징관련 유전자의 기능을 중심으로 - (Plant Disease Caused by Cucumber Mosaic Cucumovirus - Potential Role of Genes Associated with Symptom -)

  • 최장경;김혜자
    • 식물병과 농업
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    • 제5권1호
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    • pp.14-19
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    • 1999
  • Cucumber mosaic cucumovirus (CMV) is an isometric plant virus with functionally divided genomic RNAs and a broad host range. RNA 1 and RNA 2 each encode one protein, both of which are essential for replication. RNA 3 encodes the viral coat protein and an additional protein thought to be involved in potentiating the cell-to-cell movement of the virus. Functions of the RNAs have been confirmed using a pseudorecombinant virus constructed with infectious cDNA-derived transcripts of the RNAs. Generally, CMV produces different symptoms in various host plants depending on the virus strains. In this mini-review, we describe the potential role of the genes associated with symptom expression of CMV RNAs.

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Survivin as a Potential Target for Cancer Therapy

  • Soleimanpour, Elaheh;Babaei, Esmaeil
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권15호
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    • pp.6187-6191
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    • 2015
  • In 1997 for the first time, survivin was described by Amborsini et al. as an anti-apoptotic protein. Subsequent studies revealed that survivin is a multifunctional protein that plays critical roles in several crucial cell processes such as apoptosis, cell cycle, chromosome movement, mitosis and cellular stress responses. Moreover, it's overexpression in cancer cells versus normal cells is associated with chemotherapy resistance, increased tumor recurrence, and shorter patient survival. All of these features make survivin a promising target for cancer therapy. Here, we review the potential characteristics of survivin as a tumor marker.