• 제목/요약/키워드: Cell wall

검색결과 1,886건 처리시간 0.033초

Effect of the polymer wall boundary condition on the dynamic and memory behavior of the ferroelectric liquid crystal

  • Lee, Ji-Hoon;Lim, Tong-Kun;Park, Seo-Kyu;Kwon, Soon-Bum
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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    • pp.1132-1134
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    • 2006
  • In this research, we examined the correlation between the polymer wall boundary condition and the dynamic/ memory behavior of the ferroelectric liquid crystal (FLC) molecules. It was shown that the polymer wall perpendicular to the rubbing direction induces asymmetric switching to the rubbing direction and induce smaller cone angle angle of LC. On the contrary, in the cell with polymer wall parallel to the rubbing direction, the FLC molecules are oriented in the rubbing direction and shows symmetric switching and has larger cone angle. Memory behavior of each cell has strong correlation with the dynamic state of the FLC molecules. Response time of each cell was also examined.

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홍조 Rhodymeniales의 웅성생식기관에 관한 연구 (On the Male Organs of Rhodymeniales)

  • 이인규
    • Journal of Plant Biology
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    • 제12권4호
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    • pp.1-8
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    • 1969
  • According to the mode of development of antheridia and antheridial mother cells, the antheridium formation of Rhodymeniales is divided into two types. I. Separate Type; Antheridial mother cells are separate one another. Antheridia and the mother cell are surrounded by the common wall. The superficial gelatinous wall covering antheridial sori disappears during the antheridium formation. Spermatia are comparatively large. Halosaccion saccatum, H. firmum, Rhodymenia palmata and Rh. marginicrassa. II. Seriate Type; Antheridial mother cells, originated from the same epidermal cell, are seriate one another with a pit-connection. Antheridia and the mother cell do not have the common wall. The superficial gelatinous wall remains during the antheridium formation. Spermatia are comparatively small. Rhodymenia intricata, Rh. pertusa, Chrysymenia wrightii, Lomentaria hakodatensis, L. catenata, Binghamia californica and Champia parvula.

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향신료 분말의 Esdcherichia coli 와 Staphylococcus aureus 에 대한 항균작용 (Antibacterial Activity of Powdered Spice against Escherichia coli and Staphylococcus aureus)

  • 김미림;최경호;박찬성
    • 한국식품저장유통학회지
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    • 제7권1호
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    • pp.124-131
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    • 2000
  • Antibacterial activities of powdered spices(garlic , ginger, cinnamon and clove) against pathogenic Escherichia coli )157:H7 and Staphyloccus auresus were investigated. Spice powder was added in was exponetial phase of each bacterial culture . Growth inhibition was determined by the absorbance at 660nm and morphological changes of the cells were observed by transmission electron microscope (TEM). Ginger powder has the highest antibacterial activity, following cinnamon , clove and garlic has the least activity.Growth of Escherichia coli O157:H7 and Staphyloccus aureus were completely inhibited within 5 hours after addition of 1 % of garlic , 0.3% of ginger or cinnamon , 0.5% of clove powder on the exponential phase of the cells. Spice untreated cells of E. coli and S. aureus, the cytoplasm was entirely surrounded by rigid cell wall and cell walls formed a smooth layer well attached to the plasma membrane. In the cells of E. coli and S. aureus treated with spice powder, cell wall and plasma membrane were lysed and severely damaged. E.coli cells growth in the presence of spice powder showed plammolysis, the loss of electron dense material, the formation of extra cellular blebs and cytoplasm burst out from the cell. S .sureus cells grown in the presence of spice powder showed swell of cell wall, the loss of electron dense material , coagulation of cell cytoplasm and formation of extra cellular blebs. Severely damaged cells of S. aureus lost whole cytoplasm and left as ghost of the cell. Spice powder stimulated autolyssi and induced cell death.

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Micromorphology and development of the epicuticular structure on the epidermal cell of ginseng leaves

  • Lee, Kyounghwan;Nah, Seung-Yeol;Kim, Eun-Soo
    • Journal of Ginseng Research
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    • 제39권2호
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    • pp.135-140
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    • 2015
  • Background: A leaf cuticle has different structures and functions as a barrier to water loss and as protection from various environmental stressors. Methods: Leaves of Panax ginseng were examined by scanning electron microscopy and transmission electron microscopy to investigate the characteristics and development of the epicuticular structure. Results: Along the epidermal wall surface, the uniformly protuberant fine structure was on the adaxial surface of the cuticle. This epicuticular structure was highly wrinkled and radially extended to the marginal region of epidermal cells. The cuticle at the protuberant positions maintained the same thickness. The density of the wall matrix under the structures was also similar to that of the other wall region. By contrast, none of this structure was distributed on the abaxial surface, except in the region of the stoma. During the early developmental phase of the epicuticular structure, small vesicles appeared on wallecuticle interface in the peripheral wall of epidermal cells. Some electron-opaque vesicles adjacent to the cuticle were fused and formed the cuticle layer, whereas electron-translucent vesicles contacted each other and progressively increased in size within the epidermal wall. Conclusion: The outwardly projected cuticle and epidermal cell wall (i.e., an epicuticular wrinkle) acts as a major barrier to block out sunlight in ginseng leaves. The small vesicles in the peripheral region of epidermal cells may suppress the cuticle and parts of epidermal wall, push it upward, and consequently contribute to the formation of the epicuticular structure.

중금속내성균의 세포내 중금속 분포 (Distribution of Heavy Metal in the Cell Components of Heavy Metal-Tolerant Microorganisms)

  • 조주식;이원규;최형섭;허종수
    • 한국환경농학회지
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    • 제16권1호
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    • pp.55-60
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    • 1997
  • 광산폐수, 산업폐수등으로 부터 Cd, Pb, Zn 및 Cu 등 중금속에 강한 내성을 지니고 있을 뿐만 아니라 균체내 중금속 축적능력이 우수한 중금속 내성 미생물 균주 Pseudomonas putida, P. aeruginosa, P. chlororaphis 및 P. stutzeri를 각각 분리하여, 세포 구성성분별 중금속 분포 및 중금속 처리 유무에 따른 균체내 amino acid 조성변화등을 조사한 결과는 다음과 같다. 중금속이 100mg/l 농도로 첨가된 배지에서 20시간 배양한 중금속 내성균주들의 균체내 축적된 중금속의 세포 구성 성분별 분포도를 조사한 결과, Cd, Pb 및 Cu 내성균은 cell wall에 약 $50{\sim}60%$가 분포되어 있었고 cell membrane 및 cytoplasm에 각각 약 $30{\sim}40%$$10{\sim}17%$가 분포되어 있었다. 그러나 Zn 내성균주는 cell wall, cell membrane 및 cytoplasm에 각각 32%, 56% 및 13%가 분포되어 있었다. 중금속이 처리된 배지에서 배양한 중금속 내성균체의 g당 총 아미노산 함량은 중금속이 처리되지 않은 배지에서 배양한 균체에 비하여 높게 나타났으며, 산성 아미노산인 aspartic acid(Asp.+Asn.) 및 glutamic acid(Glu.+Gln)의 함량이 염기성 아미노산인 histidine, lysine, arginine에 비하여 많이 함유되어 있었다.

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전흉벽와 피하조직내 종괴로 발현한 원발성 신장암 1예 (A Case of Renal Cell Carcinoma Presented with Chest Wall Metastasis)

  • 송찬호;최형석;신동혁;양상석;이지연;한윤주;윤구섭;김기출;최신은
    • Tuberculosis and Respiratory Diseases
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    • 제48권1호
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    • pp.84-90
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    • 2000
  • 저자들은 안정시 호흡곤란을 주소로 내원하였고 흉벽에 종괴가 있었던 68세 남자환자에서 조직학적 검사상 전형적인 투명세포형의 원발성 신장암으로 진단된 1 예를 경험하였기에 문헌고찰과 함께 보고하는 바이다.

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공초점반사현미경을 이용한 소나무 유연벽공의 초미세구조 연구 (Investigation of Bordered Pit Ultrastructure in Tracheid of Korean Red Pine (Pinus densiflora) by Confocal Reflection Microscopy)

  • 권오경
    • Journal of the Korean Wood Science and Technology
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    • 제42권3호
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    • pp.346-355
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    • 2014
  • 소나무의 가도관과 유연벽공의 미세구조를 연구하는데 공초점반사현미경법을 이용하여 획득한 3차원 화상을 사용하였다. 가도관 유연벽공의 토러스, 마르고, 벽공연의 미세구조가 명확하게 관찰되었으며, 교분야벽공의 미세구조로 가도관과 방사유세포 사이의 연결구조 및 방사유세포 내의 역학적 지지구조도 관찰할 수 있었다. 가도관 세포벽의 3차원 화상에서는 S1, S2, S3층과 이 층들의 사이에 있는 이행층의 존재도 확인할 수 있었다. 또한 S3층과 S2층의 마이크로 피브릴 배향의 관찰이 가능하였고, 유연벽공 주변의 복잡한 마이크로피브릴 배향 특성도 직접적으로 확인할 수 있었다. 본 연구의 결과 공초점반사현미경법은 소나무 가도관의 세포벽, 유연벽공, 교분야벽공의 미세구조를 연구하는데 유용하게 이용될 수 있는 현미경 기법으로 여겨졌다.

Krigia속의 과피의 해부학적 구조와 분류학적 의미 (Fruit wall anatomy of the genus Krigia (Asteraceae, Lactuceae) and their taxonomic implications)

  • 이복원;박지극;박재홍
    • 식물분류학회지
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    • 제34권4호
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    • pp.321-333
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    • 2004
  • Krigia속 7종 모두와 근연속인 Nothocalais cuspidata 1종에 대해 과피 해부학적 형질을 조사하여 분류학적 유연관계를 추론하였다. 과피 해부학적 형질 중 과피의 모양, 늑의 수는 Krigia속 모든 종이 같은 형질을 공유하고 있으나, costa 의 모양, costa와 intercosta에서 중과피를 이루는 libriform 섬유세포와 fiber-sclereid 세포층의 수와 이들 세포층의 발달정도가 종간에서 차이점이 나타났다. Krigia biflora, K. cespitosa, K. occidentalis와 K. wrightii는 costa와 intercosta에서 libriform 섬유세포가 잘 발달되어있는 반면에 K. dandelion, K. montana와 K. virginica는 잘 발달되어있지 않고, 대부분 fiber-sclereid 세포로 이루어져있다. 이전 분류체계에서 Krigia 절에 속했던 K. biflora는 과피 해부학적 형질상의 차이로 볼 때 Cymbia절에 더 많은 유사성을 가지고 있다.

Observation of the Spatiotemporal Variation of Wall Charge Distribution during Reset Period in an ac POP cell

  • Jeong, Dong-Cheol;Whang, Ki-Woong
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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    • pp.756-759
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    • 2003
  • We measure the spatiotemporal wall charge distributions on sustain and address electrodes during reset period in an ac PDP cell using the longitudinal electro-optic amplitude modulation method. We apply several reset waveforms like as ramp, exponentially growing and high voltage pulse, and compare the wall charge characteristics on address electrode as well as sustain electrodes for each reset waveforms.

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Characterization of the Cloned Staphylococcal Peptidoglycan Hydrolase Gene Product

  • Lee, Yoon-Ik
    • BMB Reports
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    • 제28권5호
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    • pp.443-450
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    • 1995
  • Cloned staphylococcal peptidoglycan hydrolase was used in determining the physiological characteristics of peptidoglycan hydrolase. This enzyme hydrolyzed the bacterial cell walls and released the N-terminal alanine, but not the reducing groups. This cloned gene product was localized in the cytoplasm of transformed Escherichia coli. Activity gels indicated the enzyme had an Mr of about 54,000, which was consistent with the deduced Mr from sequencing of the cloned gene. The activity bound to CM-cellulose but not DEAE-cellulose resin, indicating it as a basic protein. Enhanced enzyme activity in a low concentration of cations, and inhibited enzyme activity in a solution with dissolved phospholipids, suggested that the activity and the availability of this basic protein may be regulated between negatively charged and positively charged cellular molecules. The activity against boiled crude cell wall was much greater than against purifed cell wall, suggesting protein associated with crude cell wall may aid in the binding of the peptidoglycan hydrolase The cloned peptidoglycan hydrolase showed positive activity on whole cells of some lysostaphin-resistant coagulase-negative staphylococci. The cloned enzyme may be an alternative for lysostaphin for lysis of staphylococci.

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