• Title/Summary/Keyword: cell separation

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Cytochemistry of cellulase in Capitate Glandular Trichomes of Pelargonium ${\times}$ fragrans (Geraniaceae)

  • Nam, Ko-Kyung;Lee, Kyung-Whan;Lee, Sang-Eun;Kim, Eun-Soo
    • 한국전자현미경학회:학술대회논문집
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    • 2007.05a
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    • pp.75-78
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    • 2007
  • The localization of cellulase were investigated in the capitate glandular trichomes of Pelargonium ${\times}$ fragransby a transmission electron microscopy. The secretory cells of capitate trichomes involved in biosynthesis and its secretion. Secretory material is transported to the space between the plasma membrane and cell wall, and subsequently accumulated in the secretory cavity. The splitting of secretory cell wall during the formation of secretory cavity is suggested that wall-forming enzymes, such as cellulase, may contribute to the wall separation process. Cellulase reaction product was localized in the secretory cell, the secretory cavity and in the subcuticular wall of glandular trichomes. Reaction products were present over fibrillar matrix in the secretory cavity associated with both the inner wall and the subcuticular wall.

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Switching characteristics of a pixel-isolated bistable twist-splay nematic liquid crystal cell

  • Song, Dong-Han;Lee, Seong-Ryong;Kim, Jae-Chang;Yoon, Tae-Hoon
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.502-504
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    • 2009
  • We demonstrate a pixel-isolated bistable twist-splay namatic (PI-BTSN) liquid crystal (LC) cell which has two stable states of splay and ${\pi}$-twist. Each state is stabilized by a multi-dimensional anchoring effect of pixel-isolating polymer walls without any chiral additives. Polymer walls are formed around the pixel region by anisotropic phase separation between LCs and reactive mesogens. Switching between the two states is archived by using vertical and horizontal electric fields. The memory mode of the fabricated LC cell has shown infinity memory time.

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Optically compensated bend cell with pixel-isolating polymer wall for a flexible display application

  • Lee, Seong-Ryong;Lee, Joong-Ha;Jang, Hong-Jeek;Jo, Jin-Seok;Yoon, Tae-Hoon;Kim, Jae-Chang
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08a
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    • pp.207-210
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    • 2007
  • We fabricated an optically compensated bend cell with pixel-isolating polymer wall. The polymer wall was formed by phase separation of LCs and UVcurable polymer. The fabricated cell had initially ${\pi}-twist$ state. It showed low driving voltage, wide viewing angle and fast response properties. Also, polymer wall provided the mechanical stability preventing distortion of a display image from pressure.

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Production of an Anticoagulant Hirudin by Fed-batch and Continuous Cell Recycle Fermentations Using Recombinant Saccharomyces cerevisiae (유가식과 세포재순환 연속공정을 이용한 항혈전제 hirudin의 생산)

  • 최치민;김명동;이상기;서진호
    • KSBB Journal
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    • v.13 no.4
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    • pp.456-460
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    • 1998
  • Fed-batch fermentations were carried out in order to improve the efficiency of hirudin production by recombinant Saccharomyces cerevisiae. A fed-batch fermentation done with the optimized semi-synthetic medium resulted in a maximum hirudin concentration of 342mg/$\ell$ by keeping a galactose concentrations between 10 and 30g/$\ell$ which corresponded to a 11.4-fold increase in hirudin concentration compared with the simple bach fermentation done with the same medium. Comparison of the chromatographic pattern of proteins in the growth medium clearly showed that the use of the semi-synthetic medium is more advantageous for separation of hirudin than the case o fusing the complex medium. Continuous cell recycle fermentation done at dilution rate of 0.1h-1 and an inlet galactose concentration of 100g/$\ell$ yielded a maximum hirudin productivity of 19.1mg hirudin/$\ell$$.$h.

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Pervaporative Butanol Fermentation Using a New Bacterial Strain

  • Park, Chang-Ho
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.1 no.1
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    • pp.1-8
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    • 1996
  • Fermentation processes for the production of butanol had an economic importance in the first part of this century. Today butanol is commercially produced from the Oxo reaction of propylene because relatively low priced propylene during the cracking of petroleum. Efforts have been made during the past decade or two to improve the productivity of butanol fermentation processes. It includes strain improvements, continuous fermentation processes, cell immobilization and simultaneous product separation. This review introduces a new butanol fermentation process using pervaporative product separation and a new bacterial strain producing less amount of organic acids. This review also compares the new process with chemical processes. This kind of new fermentation process may be able to compete with the chemical synthesis of butanol and revitalize the butanol fermentation process.

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Stability-Enhanced Liquid Crystal Mode for Flexible Display Applications

  • Jung, Jong-Wook;Jang, Se-Jin;Lee, You-Jin;Kim, Hak-Rin;Jin, Min-Young;Kim, Jae-Hoon
    • Journal of Information Display
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    • v.6 no.2
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    • pp.1-6
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    • 2005
  • We demonstrated stability-enhanced liquid crystal (LC) displays using pixel-isolated LC mode in which LC molecules are isolated in pixel by horizontal polymer layer and vertical polymer wall. The device shows good electro-optic properties against external point or bending pressure due to the polymer structures. The polymer wall acts as supporting structure from mechanical pressure and prevents the cell gap from bending. Moreover, the polymer layer acts as an adhesive to ensure a tight attachment of the two substrates. We present herein various methods for producing polymer structures by using an anisotropic phase separation from LC and polymer composites or patterned micro-structures for stable flexible liquid crystal displays.

Comparison of Panning and Sodium Polytungstate Methods for Separating Dinoflagellate Cysts (와편모조류 시스트 분리를 위한 Panning 방법과 SPT 용액방법의 비교)

  • Kang, Yoon-Ja;Moon, Chang-Ho;Cho, Hyun-Jin
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.41 no.3
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    • pp.228-231
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    • 2008
  • Two methods for separating dinoflagellate cysts from marine sediments were compared: panning and sodium polytungstate (SPT). After pretreatment with the SPT solution, Protoperidinium species had a high germination rate and cell growth rate. The germinated cells grew continuously, even in a low nutrient environment. Alexandrium cysts did not germinate, because their germination is usually active in winter. Using SPT solution, the separation process was easier, quicker, and caused much less eye fatigue than the panning method. Therefore, SPT solution offers a convenient way of pretreating dinoflagellate cysts for separation and analysis.

Magnetophoretic Microseparators for Separating Blood Cells Based on Their Native Magnetic Properties (혈액 세포의 고유자성을 이용한 마이크로 자기영동 세포분리기)

  • Jung, Jin-Hee;Han, Ki-Ho
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.32 no.11
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    • pp.856-862
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    • 2008
  • This paper presents the characterization of a continuous magnetophoretic microseparator for separating white and red blood cells from peripheral whole blood cells based on their native magnetic properties. The magnetophoretic microseparator separated the blood cells using a high gradient magnetic separation (HGMS) method without the use of additives such as magnetic beads or probing materials. Experimental results show that the paramagnetic capture mode microseparator can continuously separate out 93.5% of red blood cells and 97.4% of white blood cells from diluted whole blood, and the diamagnetic capture mode microseparator can continuously separate out 89.7% of red blood cells and 72.7 % of white blood cells by using applying an external magnetic flux of 0.2 T using a permanent magnet.

Magnetic beads separation using a multi-layered microfluidic channel (다층구조의 미세유체채널을 이용한 자성입자 분리)

  • Lee, Hye-Lyn;Song, Suk-Heung;Jung, Hyo-Il
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.1685-1686
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    • 2008
  • This paper presents the design and experiment results of a multi-layered microsystem for magnetic bead applications. The magneto-microfluidic device is designed for capable of separating magnetic beads. In the presence of the magnetic field, magnetic beads are attracted and moved to high gradient magnetic fields. A multi-layered microfluidic channel consists of top and bottom layers in order to separate magnetic beads in the vertical direction. Our channel is easily integrated magnetic cell sorter, especially on-chip microelectromagnet or permanent magnet device. Fast separation of magnetic beads in top and bottom channels can be used in high throughput screening to monitor the efficiency of blood and drug compounds.

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Prediction of Some Moving-Body Problems Using Overlapped Grid System (중첩된 격자계를 사용한 움직이는 물체의 해석)

  • Lee Jin-Gyu;Chang Keun-Shik
    • 한국전산유체공학회:학술대회논문집
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    • 1998.05a
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    • pp.82-89
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    • 1998
  • There are many moving-body problems to be solved, the solution of which necessary for proper design of flight vehicles in aerospace industry. Since a body moves relative to other bodies in the category of these problems, difficulty arises regarding both generation of computational grid around the body in motion and conservation of flow properties in the moving grid system. A few example could be store separation from the aircraft and relative vibration of multiple bodies in the high-speed flow passage. In this paper we report on the progress made in computing moving-body aerodynamics related with sabot separation characteristics. Conservative overlapping grid together with cell-merging-unmerging technique is used to solve the Euler equations for a body in high-speed motion. Carbuncle errors has to be removed before we obtain physically adequate solution. Two-dimensional application is reported here.

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