• Title/Summary/Keyword: suspension medium

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Characteristics of the Growth of Ginseng Tumor Callus (인삼 Tumor Callus의 생장 특성)

  • 최광태;양덕춘
    • Journal of Ginseng Research
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    • v.11 no.1
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    • pp.56-65
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    • 1987
  • Grown-gall tumor was induced from the infection of Panax ginseng C.A. Meyer by Agrobacterium tumefaciens C58 and the tumor calli were formed on the phytohormone free MS medium. The calli were friable and rough in appearance. Calli obtained from crown gall tumor were similar to and indistinguishable from each other. The tumor callus was quite different from normal callus. Tumor callus grew rapidly, whereas mal callus appeared late. The growth of tumor callus was better in the dark than in the light. In suspension culture, the fresh weight of tumor callus was twice as much in comparison with normal callus.

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Estimation of Cellular Damages Caused by Paraquat and lead Using a Cell Culture System

  • Park, Young-Im;Noh, Eun-Woon;Han, Mu-Seok;Yi, Yong-Sub
    • Journal of Plant Biotechnology
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    • v.3 no.2
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    • pp.83-88
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    • 2001
  • A cell culture system of poplar (Populus alba x P.glandulosa) was established to test four different methods for evaluation of cellular stresses. Two different kinds of stresses were given to the cultures by adding either Pb(NO$_3$)$_2$ or paraquat and the cellular responses were monitored during a week period. While fresh weight reduction was observable in two days after the treatment of Pb(NO$_3$)$_2$, such changes were apparent only in later stage in paraquat treated cultures. Cells in paraquat treated cultures in the first 3 days showed no alteration in fresh weight as compared to untreated cultures, but had their MTT reducing activities completely inhibited. Neither Evans blue staining nor ion conductivity of the medium was consistent with fresh weight changes of the cultures. Overall, cell clumps formed during suspension culture appeared to interfere with staining and washing reactions and thus cause the assays unreliable. Among the four methods examined, fresh weight changes and MTT reducing activity appeared to be the most reliable and consistent.

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수성이상계를 이용한 재조합 hGM-CSF의 in situ 분리

  • Pyo, Se-Hong;Myeong, Hyeon-Jong;Kim, Dong-Il
    • 한국생물공학회:학술대회논문집
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    • 2002.04a
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    • pp.321-324
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    • 2002
  • In situ recovery of recombinant human granulocyte-macrophage colony stimulating factor (hGM-CSF) was performed in transgenic Nicotiana tabacum cell suspension cultures. Aqueous two-phase systems (ATPS) were used to utilize its biocompatibility. Transgenic plant cells could be grown up to 15.7 g/L in normal medium and 18.6 g/L in ATPS composed of 6% (w/w) polyethylene glycol (PEG) 20,000 and 10% (w/w) dextran 2,000,000. It was proved that the A TPS was not harmful to cell growth. In addition, It is expected to recover hGM-CSF simultaneously with cell growth. Using this method, maximum hGM-CSF concentration at 1.64 ng/mL was obtained on day 3.

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Synthesis of Gold Nanoparticles by Chemical Reduction Method for Direct Ink Writing

  • Cho, Young-Sang;Son, Soo-Jung;Kim, Young-Kuk;Chung, Kook-Chae;Choi, Chul-Jin
    • Journal of Powder Materials
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    • v.17 no.5
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    • pp.390-398
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    • 2010
  • Aqueous gold nanoparticle dispersion was synthesized by chemical reduction method using diethanolamine as reducing agent and polyethyleneimine as dispersion stabilizer. The synthesis conditions for the stable dispersion of the gold nanoparticle suspension were determined by changing the amount of the reducing agent and dispersant during the wet chemical synthesis procedures. The face centered cubic lattice structure of the gold nanoparticles was confirmed by using X-ray diffraction and the morphologies of the nanoparticles were observed by transmission electron microscope. The synthesized gold nanoparticle dispersion was concentrated by evaporating the dispersion medium at room temperature followed by the addition of ethyleneglycol as humectant for the increase of the elastic properties to obtain gold nanoparticle inks for direct ink writing process. The line patterns were obtained with the gold nanoparticle inks during the writing procedures and the morphologies of the fine patterns were observed by scanning electron microscope.

Organic Geometry in Isabel Toledo's Collections (이사벨 톨리도 컬렉션에 나타난 유기적 기하학)

  • Yim, Eun-Hyuk
    • Journal of the Korea Fashion and Costume Design Association
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    • v.18 no.4
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    • pp.63-75
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    • 2016
  • This study examines the organic geometry in Isabel Toledo's collections in terms of the practicality of American sportswear tradition. This study conducts literary survey combined with case analysis of Toledo's works from her debut collection in 1985 to the recent ones. The organic geometry in Toledo's designs refers to the conversion of two-dimensional garment patterns into three-dimensional garment forms with the body as a medium, which is classified into the following categories in this study. First, 'fluidity' describes Toledo's highly fluid jersey dresses which maintain consistent structures by patchwork draping and suspension technique. Second, 'reductionist structure' illustrates that simple geometric shapes such as circles and squares disappear as soon as worn on the body. Third, 'origami construction' explains folding two-dimensional fabrics into three-dimensional forms, which causes the outlines of the body to appear abstract. Toledo's designs deliver the tradition of American sportswear through the organic geometry of garment construction. Toledo's works are authentic American in the aspects that they are functional and modern; they satisfy the practical needs, prioritize the movements of wearers, pursue multi-functions, and their ornamental elements are accompanied by the construction of garments. Isabel Toledo presents designs drawing on her unwavering aesthetics while continuously developing and experimenting creative ways of garment construction.

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An advanced study of multi-stage type hydrocyclone dust collector for fish egg collecting using Visualization (가시화기법을 이용한 다단형 하이드로 사이클론 어란 (魚卵) 집진장치의 개선에 관한 연구)

  • CHOI, Eunhee;PYEON, Yongbeom;LEE, Seung-heon;LEE, Kyounghoon
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.53 no.4
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    • pp.404-412
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    • 2017
  • A centrifugal cyclone dust collecting apparatus includes a hydro cyclone dust collecting apparatus for separating solid or liquid using liquid or suspension as a medium. In this study, the formation mechanism and improvement of air core and inner air layer were confirmed through Particle Image Velocimetry. These results showed that the modified experimental model was designed in the conventional method suitable for the separation of juvenile fish and eggs. The inlet speed of the multi-stage hydrocyclone dust collector, which can increase the inlet velocity and minimize floatage in the turbulence chamber, was increased from 0.15 to 0.30 m/s. As a result, the air core was stably formed, the inner air layer was increased with increasing speed. In addition, the dust collecting efficiency of egg and juvenile fish was 97.8% on average, It can infer that this system confirmed the ability to efficiently collect particles of $40{\mu}m$ or more.

Analytical Study in Brake Judder Reduction of Medium Bus (중형 버스의 브레이크 저더 현상 개선에 대한 해석적 고찰)

  • 이계섭;서권희;국종영;천인범
    • Transactions of the Korean Society of Automotive Engineers
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    • v.9 no.4
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    • pp.148-156
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    • 2001
  • Brake judder, one of low Sequency vibrations in brake system is determined by the excitation of Brake Torque Variation (BTV). The largest contributor to BTV is disc thickness variation. In this study, the static loads of brake torque at Suspension Mounting Points (SW) are obtained by the quasi-static analysis using DADS. The dynamic loads with frequency of BTV at SW are derived from correlation between forced vibration analysis with static loads and brake test results. And the accelerations at steering wheel were analyzed by forced vibration analysis with dynamic loads using commercial finite element program MSC/NASTRAN so that vibration characteristics of vehicle due to brake judder were investigated. Reliability of analysis results was verified through comparing the brake test results. Also, a parametric study with natural frequencies of frame, such as the 1st torsional mode and 1st bending mode, was conducted to reduce vibration amplitudes. As a result we could detect frame natural frequency conditions to improve vibration characteristics and obtained the frame model to reduce vibration amplitude.

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Identification of the Imperfect Stage of Mycosphaerella nawae Causing Circular Leaf Spot of Persimmon in Korea (감나무 둥근무늬낙엽병균 Mycosphaerella nawae의 불완전 세대 동정)

  • 권진혁;강수웅;박창석;김희규
    • Korean Journal Plant Pathology
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    • v.14 no.5
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    • pp.397-401
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    • 1998
  • Asexual spores of Mycosphaerella nawae were profusely produced on PDA after a prolonged incubation at $25^{\circ}C$ for 90 days. When persimmon trees were artificially inoculated by the conidial suspension, typical symptoms of circular leaf spot of persimmon appeared on the leaves two month later. The imperfect stag of the fungus was identified as Ramularia sp. based on following morphological characteristics examined under a light microscope and a scanning electron microscope. Conidia were mostly ellipsoid, but occasionally cylindrical, elongated oval, taro, peanut or gourd shapes and measured as 12.2~32.6$\times$6.1~10.2 ${\mu}{\textrm}{m}$. erect, hyaline, colorless-light brown. Conidia were formed solitarily or in chains on a medium and infected leaves. Conidiophore was erect, hyaline, colorless-light brown. and the size was 20.4~102.0$\times$3.1~10.2 ${\mu}{\textrm}{m}$, respectively. In this paper, we firstly demonstratrated that asexual spores of M. nawae induced persimmon circular leaf spot in nature as well as sexual spores of the fungus. Therefore, it is hypothesized that the imperfect stage of the fungus plays an important role in nature for epidemics as secondary inoculum.

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Determinants of Plant Growth-promoting Ochrobactrum lupini KUDC1013 Involved in Induction of Systemic Resistance against Pectobacterium carotovorum subsp. carotovorum in Tobacco Leaves

  • Sumayo, Marilyn;Hahm, Mi-Seon;Ghim, Sa-Youl
    • The Plant Pathology Journal
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    • v.29 no.2
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    • pp.174-181
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    • 2013
  • The plant growth-promoting rhizobacterium Ochrobactrum lupini KUDC1013 elicited induced systemic resistance (ISR) in tobacco against soft rot disease caused by Pectobacterium carotovorum subsp. carotovorum. We investigated of its factors involved in ISR elicitation. To characterize the ISR determinants, KUDC1013 cell suspension, heat-treated cells, supernatant from a culture medium, crude bacterial lipopolysaccharide (LPS) and flagella were tested for their ISR activities. Both LPS and flagella from KUDC1013 were effective in ISR elicitation. Crude cell free supernatant elicited ISR and factors with the highest ISR activity were retained in the n-butanol fraction. Analysis of the ISR-active fraction revealed the metabolites, phenylacetic acid (PAA), 1-hexadecene and linoleic acid (LA), as elicitors of ISR. Treatment of tobacco with these compounds significantly decreased the soft rot disease symptoms. This is the first report on the ISR determinants by plant growth-promoting rhizobacteria (PGPR) KUDC1013 and identifying PAA, 1-hexadecene and LA as ISR-related compounds. This study shows that KUDC1013 has a great potential as biological control agent because of its multiple factors involved in induction of systemic resistance against phytopathogens.

Development of Cell Line Preservation Method for Research and Industry Producing Useful Metabolites by Plant Cell Culture

  • Cho, Ji-Suk;Chun, Su-Hwan;Lee, Song-Jae;Kim, Ik-Hwan;Kim, Dong-Il
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.5 no.5
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    • pp.372-378
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    • 2000
  • The cell culture of Angelica gigas Nakai producing decursin derivatives and immunostimulating polysaccharides was preserved in liquid nitrogen after pre-freezing in a deep freezer at -70$^{\circ}C$ for 480 min. The effects of the cryoprotectant and pretreatment before cooling were investigated to obtain the optimal procedure for cyropreservation. When compared to mannitol, sorbitol, or NaCl with a similar osmotic pressure, 0.7 M sucrose was found to be the best osmoticum for the cryopreservation of A. gigas cells. In the pre-culture medium, the cells in the exponential growth phase showed phase showed the best post-freezing survival after cryopreservation. A mixture of sucrose, glycerol, and DMSO was found to be an effective cryoprotectant and a higher concentration of the cryoprotectant provided better cell viability. When compared with the vitrification, the optimum cryopreservation method proposed in this study would seem to be more effective for the long-term storage of suspension cells. The highest relative cell viability established with the procedure was 89%.

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