• 제목/요약/키워드: Cell formation

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광합성세균에 의한 미생물막의 형성

  • 오광근;이철우;전영중;이재홍
    • 한국미생물·생명공학회지
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    • 제24권6호
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    • pp.733-737
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    • 1996
  • The formation of microbial films(biofilm) by a non-sulfur phototrophic bacteria, Rhodopseudomonas capsulata, on inorganic media was studied. Porous ceramic beads(PCB) were superior to other immobilizing media for the biofilm formation in a packed-bed reactor. It was found that the formation of microbial films favored a lower hydraulic retention time, showing a higher ratio of cells attatched to the media to those suspended in the solution. The cell concentration in the biofilm reactor was as high as 11,400mg/l, which is 8-folds of the cell concentration in an ordinary suspended treatment. It was observed that the formation of micribial film by R. capsulata followed a general serial process of cell attachment, microcolony formation, and biofilm formation. The microbial films thus formed was very stable even for an extremely high volumetric BOD loading rate of 15gBOD/l day. The scanning electron micrographs of the microbial films showed that the cells were attached to both the surface and pores of the media.

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Effect of Culture Conditions on Astaxanthin Formation in Red Yeast Xanthophyllomyces dendrorhous Mutant JH1

  • Kim Jeong-Hwan;Choi Seok-Keun;Park Young-Sam;Yun Cheol-Won;Cho Won-Dai;Chee Kew-Mahn;Chang Hyo-Ihl
    • Journal of Microbiology and Biotechnology
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    • 제16권3호
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    • pp.438-442
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    • 2006
  • The formation of astaxanthin by Xanthophyllomyces dendrorhous mutant JH1 depends on the culture conditions. Therefore, the effects of inoculation rate (1-5%, v/v) and medium compositions (various carbon and nitrogen sources) on cell growth and astaxanthin formation in X. dendrorhous mutant JH1 were investigated. Inoculation at 3% (v/v) was optimal for cell growth and astaxanthin formation. The most effective carbon source for cell growth and astaxanthin formation was glucose, and the best nitrogen source was yeast extract. The 3% (w/v) glucose and 0.2% (w/v) yeast extract showed the best effect on cell growth and astaxanthin formation, compared with others tested. The 3% glucose, 0.2% yeast extract, $0.15%\;KH_{2}PO_{4}$, $0.05%\;MgSO_4$, $0.01%\;MnSO_4$, and $0.01%\;CaCl_2$ were selected for cell growth and astaxanthin formation. Under the conditions selected, the maximum concentrations of cell and astaxanthin obtained after 168 h of cultivation were 5.43 g/l and 28.20 mg/l, respectively.

Quenching을 이용한 $1\mu{m}$ 미만의 Cell 형성 (Formation of cell under $1\mu{m}$ by quenching)

  • 이병희;차성운
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2005년도 춘계학술대회 논문집
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    • pp.1420-1423
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    • 2005
  • Micro Cellular Plastics create a sensation at polymer industrial for lowering product cost & overcoming a lowering of mechanical intensity. Reduction of MCPs cell size increases the intensity of MCPs. This research based on the experiment about cell size reduction method. At this study, Quenching & Pressure foaming process are introduced to one of methods. Conclusion of study is that Quenching process is the simplest process for nano cell formation.

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Adaptive Clustering Algorithm for Recycling Cell Formation: An Application of the Modified Fuzzy ART Neural Network

  • Park, Ji-Hyung;Seo, Kwang-Kyu
    • 한국데이타베이스학회:학술대회논문집
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    • 한국데이타베이스학회 1999년도 춘계공동학술대회: 지식경영과 지식공학
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    • pp.253-260
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    • 1999
  • The recycling cell formation problem means that disposal products me classified into recycling part families using group technology in their end of life phase. Disposal products have the uncertainties of product status by usage influences during product use phase and recycling cells are formed design, process and usage attributes. In order to treat the uncertainties, fuzzy set theory and fuzzy logic-based neural network model are applied to recycling cell formation problem far disposal products. In this paper, a heuristic approach fuzzy ART neural network is suggested. The modified fuzzy ART neural network is shown that it has a great efficiency and give an extension for systematically generating alternative solutions in the recycling cell formation problem. We present the results of this approach applied to disposal refrigerators and the comparison of performances between other algorithms. This paper introduced a procedure which integrates economic and environmental factors into the disassembly of disposal products for recycling in recycling cells. A qualitative method of disassembly analysis is developed and its ai is to improve the efficiency of the disassembly and to generated an optimal disassembly which maximize profits and minimize environmental impact. Three criteria established to reduce the search space and facilitate recycling opportunities.

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Adaptive Clustering Algorithm for Recycling Cell Formation An Application of the Modified Fuzzy ART Neural Network

  • Park, Ji-Hyung;Seo, Kwang-Kyu
    • 한국지능정보시스템학회:학술대회논문집
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    • 한국지능정보시스템학회 1999년도 춘계공동학술대회-지식경영과 지식공학
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    • pp.253-260
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    • 1999
  • The recycling cell formation problem means that disposal products are classified into recycling part families using group technology in their end of life phase. Disposal products have the uncertainties of product status by usage influences during product use phase and recycling cells are formed design, process and usage attributes. In order to treat the uncertainties, fuzzy set theory and fuzzy logic-based neural network model are applied to recycling cell formation problem for disposal products. In this paper, a heuristic approach for fuzzy ART neural network is suggested. The modified Fuzzy ART neural network is shown that it has a great efficiency and give an extension for systematically generating alternative solutions in the recycling cell formation problem. We present the results of this approach applied to disposal refrigerators and the comparison of performances between other algorithms. This paper introduced a procedure which integrates economic and environmental factors into the disassembly of disposal products for recycling in recycling cells. A qualitative method of disassembly analysis is developed and its aim is to improve the efficiency of the disassembly and to generated an optimal disassembly which maximize profits and minimize environmental impact. Three criteria established to reduce the search space and facilitate recycling opportunities.

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지치(Lithospermum erythrorhizon S.)의 캘러스배양에서 Shikonin 유도체 생산에 미치는 저선량γ선의 효과 (Effects of Low Dose Gamma Radiation on the Formation of Shikonin Derivatives on Callus Cultures of Lithospermum erythrorhizon)

  • 황혜연;김재성;이영복
    • Journal of Plant Biotechnology
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    • 제30권3호
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    • pp.293-299
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    • 2003
  • The effects of low dosage ${\gamma}$-radiation on the cell growth and the formation of shikonin derivatives were investigated in callus cultures of Lithospermum erythrorhizon under different medium and light conditions. Gamma radiation significantly affected the cell growed and formation of shikonin derivatives, depending on the culture conditions. In the cell cultures grown on M-9 medium, 2Gy and 16Gy of ${\gamma}$-radiation increased the calli growth and the formation of shikonin derivatives, respectively under 16hr day light condition. When calli were cultured for 60 days in the dark after irradiation of ${\gamma}$-radiation, cell growth was increased at low dosage of 1Gy and 2Gy in LS medium containing BA 2mg/L and IAA 0.2mg/L. Interestingly, calli grown in M-9 medium by 2Gy irradiation for 60 days significantly stimulated the formation of shikonin derivatives(13.21mg/g cell fresh wt), which was approximately 6 times higher than untreated cells.

호르몬을 투여한 Rat 난관상피세포(卵管上皮細胞)의 전자현미경적 관찰 (Electron Microscopic Observations of Oviductal Epithelium of the Rats Treated with Hormone)

  • 이재현
    • 대한수의학회지
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    • 제22권2호
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    • pp.99-109
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    • 1982
  • Morphological changes of the oviductal epithelium of the rat treated with hormones ($17{\beta}$-estradiol ${\mu}g$/day and progesterone 2.5mg/day) for ten days were observed transmission and scanning electron microscopically. The results obtained were as follows: 1. The cilia formation of ciliary cell(CC) was more accelerated by the treatment of estradiol than progesterone, but the balance of estrogen and progesterone was required for the maintenance of CC. The effect of hormone was different between the segments for the maintenance of CC. 2. The short secretory cell(SSC) was severely inhibited in the formation of secretory granules with single hormonal treatment but the activity of secretion was more inhibited by progesterone than by estradiol. 3. The long secretory cell(LSC) had not a great difference between estradiol and progesterone treatments as compared with the normal sexual cycle, but the formation of secretory granules was somewhat accelerated by progesterone treatment. 4. The formation of secretory granules of junctional cell (JC) was severely accelerated by estradiol treatment as compared with the normal sexual cycle. The formation of secretory granules during progesterone treatment, on the other hand, was inhibited completely, but the numbers of pinocytotic vesicles appeared at the cytoplasmic apical portion. 5. Three types of secretory cells, SSC, LSC and JC, on the rat oviductal epithelium could be suggested to have different cell tapes respectively from the morphological changes by hormone treatment.

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Control of Asymmetric Cell Divisions during Root Ground Tissue Maturation

  • Choi, Ji Won;Lim, Jun
    • Molecules and Cells
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    • 제39권7호
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    • pp.524-529
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    • 2016
  • Controlling the production of diverse cell/tissue types is essential for the development of multicellular organisms such as animals and plants. The Arabidopsis thaliana root, which contains distinct cells/tissues along longitudinal and radial axes, has served as an elegant model to investigate how genetic programs and environmental signals interact to produce different cell/tissue types. In the root, a series of asymmetric cell divisions (ACDs) give rise to three ground tissue layers at maturity (endodermis, middle cortex, and cortex). Because the middle cortex is formed by a periclinal (parallel to the axis) ACD of the endodermis around 7 to 14 days post-germination, middle cortex formation is used as a parameter to assess maturation of the root ground tissue. Molecular, genetic, and physiological studies have revealed that the control of the timing and extent of middle cortex formation during root maturation relies on the interaction of plant hormones and transcription factors. In particular, abscisic acid and gibberellin act synergistically to regulate the timing and extent of middle cortex formation, unlike their typical antagonism. The SHORT-ROOT, SCARECROW, SCARECROW-LIKE 3, and DELLA transcription factors, all of which belong to the plant-specific GRAS family, play key roles in the regulation of middle cortex formation. Recently, two additional transcription factors, SEUSS and GA- AND ABA-RESPONSIVE ZINC FINGER, have also been characterized during ground tissue maturation. In this review, we provide a detailed account of the regulatory networks that control the timing and extent of middle cortex formation during post-embryonic root development.

Hesperidin Inhibits Vascular Formation by Blocking the AKT/mTOR Signaling Pathways

  • Kim, Gi Dae
    • Preventive Nutrition and Food Science
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    • 제20권4호
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    • pp.221-229
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    • 2015
  • Hesperidin has been shown to possess a potential inhibitory effect on vascular formation in endothelial cells. However, the fundamental mechanism for the anti-angiogenic activity of hesperidin is not fully understood. In the present study, we evaluated whether hesperidin has anti-angiogenic effects in mouse embryonic stem cell (mES)-derived endothelial-like cells, and human umbilical vascular endothelial cells (HUVECs), and evaluated their mechanism via the AKT/mammalian target of rapamycin (mTOR) signaling pathway. The endothelial cells were treated with several doses of hesperidin (12.5, 25, 50, and $100{\mu}M$) for 24 h. Cell viability and vascular formation were analyzed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and tube formation assay, respectively. Alteration of the AKT/mTOR signaling in vascular formation was analyzed by western blot. In addition, a mouse aortic ring assay was used to determine the effect of hesperidin on vascular formation. There were no differences between the viability of mES-derived endothelial-like cells and HUVECs after hesperidin treatment. However, hesperidin significantly inhibited cell migration and tube formation of HUVECs (P<0.05) and suppressed sprouting of microvessels in the mouse aortic ring assay. Moreover, hesperidin suppressed the expression of AKT and mTOR in HUVECs. Taken together, these findings suggest that hesperidin inhibits vascular formation by blocking the AKT/mTOR signaling pathways.

퍼지 이론에 기초한 머신-셀 구성방법 (A machine-cell formation method based on fuzzy set)

  • 이노성;임춘우
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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    • pp.1565-1568
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    • 1997
  • In this paper, a fuzzy based machine-cell formation algorithm for cellular manufacturing is presented. The fuzzy lovic is employed to express the degree of appropriateness when alternative machnies are specified to process a part shape. For machine grouping, the similarity coefficient based approach is used. The algorithm produces efficient machine cells and part families which maximize the similarity values.

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