• 제목/요약/키워드: cell wall.

검색결과 1,896건 처리시간 0.022초

Thymol and eugenol in essential oils enhance phage endolysin LysECP26-mediated cell wall disruption of Escherichia coli O157:H7

  • Park, Do-Won;Lee, Jong Hun;Park, Jong-Hyun
    • 한국식품과학회지
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    • 제53권6호
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    • pp.819-822
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    • 2021
  • To enhance phage endolysin-mediated cell wall disruption of Escherichia coli O157:H7, the cells were co-treated with aromatic compounds, namely thymol or eugenol, found in essential oils and endolysin LysECP26. Interestingly, the minimal inhibitory concentrations of LysECP26 was four times lower when used in combination with either of the two compounds than when it was used alone. This synergistic activity was also confirmed by viable cell counting. Within 1 h of LysECP26 and eugenol or thymol co-treatment to the cells, there was a 2.3 or 3.8 log CFU/mL reductions, respectively. Additionally, field emission scanning electron microscopy showed cell wall disruption and severe morphological alterations of the cells in case of the combination treatments. Therefore, endolysin and thymol or eugenol co-treatment can help in developing efficient bio-control strategies against gram-negative pathogen E. coli O157:H7.

Research on three-point bending fatigue life and damage mechanism of aluminum foam sandwich panel

  • Wei Xiao;Huihui Wang;Xuding Song
    • Steel and Composite Structures
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    • 제51권1호
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    • pp.53-61
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    • 2024
  • Aluminum foams sandwich panel (AFSP) has been used in engineering field, where cyclic loading is used in most of the applications. In this paper, the fatigue life of AFSP prepared by the bonding method was investigated through a three-point bending test. The mathematical statistics method was used to analyze the influence of different plate thicknesses and core densities on the bending fatigue life. The macroscopic fatigue failure modes and damage mechanisms were observed by scanning electron microscopy (SEM). The results indicate that panel thickness and core layer density have a significant influence on the bending fatigue life of AFSP and their dispersion. The damage mechanism of fatigue failure to cells in aluminum foam is that the initial fatigue crack begins the cell wall, the thinnest position of the cell wall or the intersection of the cell wall and the cell ridge, where stress concentrations are more likely to occur. The fatigue failure of aluminum foam core usually starts from the semi-closed unit of the lower layer, and the fatigue crack propagates layer by layer along the direction of the maximum shear stress. The results can provide a reference for the practical engineering design and application of AFSP.

Paeonia lactiflora Inhibits Cell Wall Synthesis and Triggers Membrane Depolarization in Candida albicans

  • Lee, Heung-Shick;Kim, Younhee
    • Journal of Microbiology and Biotechnology
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    • 제27권2호
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    • pp.395-404
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    • 2017
  • Fungal cell walls and cell membranes are the main targets of antifungals. In this study, we report on the antifungal activity of an ethanol extract from Paeonia lactiflora against Candida albicans, showing that the antifungal activity is associated with the synergistic actions of preventing cell wall synthesis, enabling membrane depolarization, and compromising permeability. First, it was shown that the ethanol extract from P. lactiflora was involved in damaging the integrity of cell walls in C. albicans. In isotonic media, cell bursts of C. albicans by the P. lactiflora ethanol extract could be restored, and the minimum inhibitory concentration (MIC) of the P. lactiflora ethanol extract against C. albicans cells increased 4-fold. In addition, synthesis of $(1,3)-{\beta}-{\small{D}}-glucan$ polymer was inhibited by 87% and 83% following treatment of C. albicans microsomes with the P. lactiflora ethanol extract at their $1{\times}MIC$ and $2{\times}MIC$, respectively. Second, the ethanol extract from P. lactiflora influenced the function of C. albicans cell membranes. C. albicans cells treated with the P. lactiflora ethanol extract formed red aggregates by staining with a membrane-impermeable dye, propidium iodide. Membrane depolarization manifested as increased fluorescence intensity by staining P. lactiflora-treated C. albicans cells with a membrane-potential marker, $DiBAC_4(3)$ ((bis-1,3-dibutylbarbituric acid) trimethine oxonol). Membrane permeability was assessed by crystal violet assay, and C. albicans cells treated with the P. lactiflora ethanol extract exhibited significant uptake of crystal violet in a concentration-dependent manner. The findings suggest that P. lactiflora ethanol extract is a viable and effective candidate for the development of new antifungal agents to treat Candida-associated diseases.

흉벽침습이 있던 T3 비소세포암환자의 완전절제후의 결과 (Result of Complete Resection of T3 Non-Small Cell Lung Cancer Invading the Chest Wall)

  • 최창휴;임수빈;김재현;조재일;백희종;박종호
    • Journal of Chest Surgery
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    • 제34권12호
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    • pp.924-929
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    • 2001
  • 배경 : 흉벽을 침습한 비소세포암의 외과적 절제후의 장기 생존율에는 현재까지 림프절 전이, 완전 절제, 흉벽침습 깊이 등이 관여한다고 알려져 있다. 본 연구에서는 완전절제후의 예후에 관련된 요소들에 대해 알아보고자 한다. 대상 및 방법 : 1988년부터 1998년까지 원발성 비소세포암으로 수술을 받은 680명중, 벽측늑막과 흉벽을 침범한 경우에 완전절제를 실시한 55예(8.0%)에 대해 후향적 방법을 통해 분석하였다. 결과 : 29예(47.3%)에서 총괄절제를 시행하고 26예(52.7%)에서 늑막외절제를 실시하였다. 늑막외절제를 시행한 모든 예에서 침습정도는 벽측늑막에 국한되어 있었고, 총괄절제군에서는 9예(31.0%)에서 벽측늑막에 나머지 20예(69.0%)에서는 흉벽에의 침습이 병리학적으로 판명되었다. 수술사망은 3명에서 발생해 5.4%였으며, 추적은 100%에서 가능하였다. 전체환자군의 5년 생존율은 26%였으며, T3N0M0군의 생존율이 29%로 T3N2M0군의 18% 보다 높기는 하나 통계학적인 유의성은 없었다.(p=0.35) 흉벽침습 깊이정도에 따른 생존율은 림프절 전이의 유무에 관련없이 유의한 차이가 없었다.(p=0.99) 결론 : 흉벽을 침습한 T3 비소세포암에 대해 완전절제를 실시해 만족할 만한 생존율을 보였다. 림프절 전이 여부는 완전절제후의 생존율에 관여하는 바가 크나, 침습 깊이는 관여하는 정도가 덜하다.

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Coryne형 제균의 원형질체 융합빈도 향상 (Frequency improvement of protoplast fusion in coryneform bacteria)

  • 김종헌;임번삼;이세영;전문진
    • 미생물학회지
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    • 제23권3호
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    • pp.190-196
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    • 1985
  • For frequency improvement of protoplast fusion in Brevibacterium flavum, Brevibacterium lactofermentum lactofermentum and Corynebacterium glutamicum, the effect of plasma expanders on fusion and cell wall regeneration, compatison between direct and two-step selection method, tendency of fusion frequency according to pH of fusion fluid and polyethylene glycol concentration were examined. By addition of 3% polyvinyl pyrrolidone to cell wall regeneration medium, regeneration frequencies were expressed 23 (Brevibacterium lactofermentum), 10.4 (Brevibacterium flavum) and 2.7 (Corynebacterium glutamicum) times higher than those of none polyvinyl pyrrolidone medium respectively.

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Switching current density for spin transfer torque magnetic random access memory with Dzaloshinskii-Moriya Interaction

  • Song, Kyungmi;Lee, Kyung-Jin
    • 한국자기학회:학술대회 개요집
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    • 한국자기학회 2015년도 임시총회 및 하계학술연구발표회
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    • pp.78-79
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    • 2015
  • We investigate the switching current for various cell diameters and DM interaction. We find that the current density for switching can depend strongly on the cell size when the switching is governed by the domain wall motion. Moreover the switching current density is also strongly influenced by DM interaction. In the presentation, we will discuss the effect of domain wall formation and more various DMI constant on the switching current desity in detail.

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Erwinia rhapontici의 Pectate Lyase를 유도하는 식물 세포벽 (Plant Cell Wall as an Inducer of Pectate Lyase of Erwinia rhapontice)

  • 최재을;한광섭
    • 한국식물병리학회지
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    • 제12권1호
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    • pp.129-131
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    • 1996
  • Pecatate lyase(Pel)는 펙틴과 펙틴산을 분해하며, 기주식물의 감염에 관여한다. Erwinia rhapontici에 있어서 기주와 병원균이 병원성과의 상호관계를 구명하기 위하여 pectate lyase(Pel) 활성에 미치는 식물체 추출물과 세포벽의 효과를 검토하였다. 본 균은 glycerol이 포함된 minimal salts(MSG) 배지와 식물체 추출물이 첨가된 MSP 배지에서는 Pel 활성이 검출되지 않았다. 그러나 배추, 상추 잎, 감자 괴경, 셀러리 잎자루, 양파 인경, 당근 뿌리의 세포벽이 첨가된 MSP 배지에서는 Pel의 활성이 검출되었다. Pel을 유도하는 식물 인자는 불용성이고, 열처리에 불안전하였다.

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악성 늑막 림프종이 합병된 만성 농흉 1례 (A Case of Lymphoma Developing From the Wall of Chronic Empyema)

  • 김길동
    • Journal of Chest Surgery
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    • 제26권7호
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    • pp.571-574
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    • 1993
  • We present a rare case of malignant lymphoma developing from the wall of chronic empyema thoracis. A 54-year old man with a 35 year history of tuberculosis empyema was admitted due to right chest pain and general weakness for 2 months. Under the impression of chronic empyema thoracis with destroyed right lung and tumor on posterior costophrenic sulcus, pleuropneumonectomy including tumor was performed as a single procedure through a right thoracotomy. The tumor arose from the thickened pleura, and it was histologically and immunologically diffuse large cell[non-cleaved] B-cell non-Hodgkin`s lymphoma [NHL]

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식물세포벽 가수분해효소 중 펙틴계효소에 대한 고찰 (Respection of Pectic Enzymes Among the Hydrolysis Enzymes of Plant Cell Wall)

  • 최동원;김인규
    • 한국식품영양학회지
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    • 제9권1호
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    • pp.92-98
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    • 1996
  • Pectic materials, which are widely spread in the plant cell wall as plant carbohydrates, plays a great role in food Industry that acts as a softening agent of fruits and vegetables, and gel forming agents. To study physiochemical properties and industrial applications of pectic enzymes that hydrolyzes pectin, classification, assay method and Industrial application are reviewed based on previous results.

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Observation of Soft-Rot Wood Degradation Caused by Higher Ascomyceteous fungi

  • Lee, Yang-Soo
    • Mycobiology
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    • 제28권1호
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    • pp.47-50
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    • 2000
  • The capability of higher ascomyceteous fungi to cause typical soft-rot decay for wood under laboratory conditions is reviewed and discussed. Fungi tested were extremely active in the decomposition of timbers. Scanning electron micrographs illustrated typical soft-rot decay pattern of higher wood decay ascomycetes, with the exception of H. trugodes that caused white-rot decay. Most of the fungi tested could be grouped as soft-rot fungi that showed typical soft-rot type II. Hypha confined primarily to the resin canals in softwoods or vessel elements in hardwoods and spread tracheid to tracheid via pits of cell wall to cell wall with mechanical force.

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