• KSBB Journal
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• 제22권4호
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• pp.185-190
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• 2007

Productivity of secreted recombinant protein depends largely on its stability in the extracellular environment with protease. Most hGM-CSF produced by transgenic tobacco cell cultures and secreted to the medium was confirmed to be rapidly degraded by protease in medium. To increase the productivity, therefore, various protein stabilizers such as gelling agents such as carrageenan and alginate, polymers, polyols, and amino acids have been tested. The stability of hGM-CSF in spent medium without cells was improved by the presence of gelling agents. However, the reason for the enhanced production by the addition of gelling agents may be due to the increased expression level and permeability rather than stability. The addition of DMSO inhibited the cell growth, but improved specific yield. The others were not effective for stability as well as hGM-CSF production.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XIII)
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• pp.329-333
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• 2003

본 연구에서는 형질전환된 N. tabacum 배양에 있어서 배양 중반 저온으로의 변환이 세포에 미치는 영향과 hGM-CSF의 생산성 변화를 관찰하였다. 배양 중반 저온으로의 변환은 DCW의 증가와 세포크기의 감소를 보였다. Ascorbic acid의 첨가는 배양초기 세포 생존율의 감소를 완화시켰으며, 배양 중반 저온으로의 변환은 약간의 세포생존율 감소를 보였다. 저온으로의 변환, 저온 배양에서의 betaine 첨가, ascorbic acid 첨가 모두 배양 후반 세포 lysis 억제에 효과가 있었다. 배양 중반 저온으로의 변환시 배지내 단백질 분해 효소의 활성을 측정한 결과, 대조구 세포에 비해 낮은 단백질 분해 효소 활성을 나타내었다. 그로인해 배양 중반 이후 단백질 분해 효소에 의한 급격한 hGM-CSF 분해를 감소시킴으로써 상대적으로 대조구 세포에 비해 높은 hGM-CSF 생산성을 유지시켰다. Ascorbic acid를 첨가한 후 배양 도중 betaine(1 mM)을 첨가하여 저온으로 온도를 변환시, hGM-CSF의 생산성 대조구 세포에 비하여 최대 2.1배 까지 높게 유지시켰다.

• 폴리머
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• 제30권4호
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• pp.286-292
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• 2006

Super water-absorbent resins were prepared by inverse suspension copolymerization of sodium acrylate, acrylamide and 2-hydroxyethyl acrylate using N, N'-methylene-bis-acrylamide as cross-linker. For the suspension copolymerization, monohexadecyl phosphate was employed as the dispersing agent, cyclohexane as the dispersing medium and potassium persulfate as the initiator. The dependence of water-absorption capacity on the amount of crosslinking agent, oil/water ratio, degree of neutralization and the composition of the copolymer were systematically investigated. Furthermore, the swelling kinetics of the super water-absorbent copolymer was carried out. The absorption of the resins is more than 1800 g/g for deionized water and 100 g/g for 0.9% NaCl solution, respectively. The copolymers showed an increased salt resistance and enhanced water retention of soil.

• 한국신뢰성학회지:신뢰성응용연구
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• 제12권2호
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• pp.79-90
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• 2012

The torsion beam type of rear suspension has been adopted by most manufactures of small to medium front wheel drive passenger cars. Previous studies analyzed only the load characteristics of CTBA(the coupled torsion beam axle)'s components. This paper analyzed the results of measurement after measuring loads and displacements, angles when a car equipped with the coupled torsion beam axle is driving in various roads. The most important durability factors for CTBA part are the force and direction of rear CTBA trailing arm. If there are design changes, it was difficult to make a sensor and install each time for measuring the trailing arm forces. After analyzing the loading histories between body and chassis, we developed the transformation matrix that can be converted to mutual force. This paper also deals with the analysis of the force behavior through the analysis of the influence and correlation between the body and chassis parts of cars.

• Journal of Plant Biotechnology
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• 제6권2호
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• pp.91-96
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• 2004

The use of liquid-medium-based procedure relative to the solid media led to a 4.5-fold increase in the number of cotyledon-stage embryos. The most efficient system for multiplication and regeneration of somatic embryos was CP6 procedure with the media MSD40/MSD20/MSM6AC/FNL0S3S3GM. However, the rate of regeneration was lower. About 71％ of the embryos with dicotyledon were continued to develop the roots after desiccation treatment and 92％ of the germinated embryos produced shoots in 10 days. Of the four morphologically different types of embryos, dicotyledonous ones showed a high frequency of conversion, while only a few with fused and horn type cotyledon developed shoots. Mature somatic embryos were desiccated in empty petri dishes for 12-72 h. Embryo survival rate was the highest after 12 h of desiccation, but maximal germination was observed at 24 h. After desiccation, they were placed on MS medium without growth regulators for germination. Germinating embryos were transferred to small pots with vermiculite for plant regeneration. The etiolating the plants during the growth was resolved to add 1％ activated charcoal on hormone-free MS medium.

• 식물조직배양학회지
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• 제21권3호
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• pp.167-171
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• 1994

두릅나무의 현탁배양에서 체세포배 형성과 식물체 재생의 가능성을 알아보고자 배발생 캘러스 유도조건과 배지농도 및 삼투조절제의 영향을 조사하였다. 어린 엽보다 엽병에서 캘러스 유도가 양호하였고, 2,4-D 단독처리보다는 2,4-D 1.0, 2.0 mg/L + TDZ 0.1 mg/L 처리에서 캘러스 유도량과 배발생 캘러스의 빈도가 가장 양호하였다. MS 기본배지의 농도를 1/4으로 줄인 1/4 $\times$ MS배지가 배형성과 생육에 가장 효과적이었으며 2 $\times$ MS, 1/8 $\times$ MS에서는 배형성이 억제되는 경향이었다. 1/4 $\times$ MS 배지에 surcrose 1.5%를 처리하고 mannitol을 첨가했을 때는 체세포배 발생이 억제되었지만 insitol 경우 체세포배 형성을 촉진할 뿐만 아니라 배발생의 동조화와 비정상적인 배발생의 억제효과도 있었다. 식물체 분화는 현탁배양에서 형성된 성숙한 체세포배를 생장조절제가 처리되지 않은 MS 기본배지에 치상하여 배양 4주 후에 86%의 정상식물체를 얻을 수 있었고 분화식물체를 순화과정을 거쳐 버미큐라이트에 이식한 결과 50%의 토양활착율을 보였다.

• KSBB Journal
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• 제7권2호
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• pp.96-101
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• 1992

저혈청 배지의 개발을 위해 혈청 대체 가능성이 있는 물질을 선정하여 각각의 필요성을 검색하였다. 검색 결과 결정된 물질들로 저혈청 배지를 제조하였으며, 기저 배지의 종류와 혼합에 따른 영향을 고찰 하였다. 개발된 배지는 1% FBS 첨가만으로 6개월 이상의 계대배양에서 만족할만한 안정성을 보였으며, 부유배양에도 적합한 것으로 판단되었다. 개발된 배지에서 혈청은 필수적이었으나 균주의 장기적응후에 무혈청 배지의 개발이 보다 용이할 것으로 기대되었다.

• Journal of Plant Biology
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• 제32권4호
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• pp.275-283
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• 1989

$\beta$-1, 4-endoglucanase (EC 3, 2, 1, 4) was isolated and purified from Nicotiana tabaccum L. Var. Virginia 115 suspensin cultured cells. The molecular weight as estimated by Sephadex G-100 was about 14, 000. The optimum pH for activity was 5.4. The Km value for carboxymethyl cellulose was 0.18 mg/unit and the enzyme was quite resistant to heating. Polyamine did not affect the activity of $\beta$-1, 4-endoglucanase in vitro but the activity increased drastically when polyamines were added in the suspension culture medium. It is suggested that increase in $\beta$-1, 4-endoglucenase activity due to polyamine might be related to growth of the plant.

• 식물조직배양학회지
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• 제27권1호
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• pp.47-50
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• 2000

당류의 수송속도는 당류 고갈동안 증가되었고, 당류 고갈 3일째에 최대 수송속도를 보였다. 당류 고갈로 유도된 당류 수송계는 cycloheximide에 의해서 완전히 방해되었다 선천적으로 식물에서 당류 수송계는 하나이나 당류 고갈동안 유도된 포도당 수송은 포화상태를 보이고, 설탕 수송은 포화되지 않았다. 유도된 당류 수송계는 선천적인 당류 수송계와는 다른 kinetic을 보였다. 이 결과는 고등식물도 불리한 조건하에서 새로운 수송계를 유도시킬 수 있는 능력이 있음을 보여주었다.

• Plant Biotechnology Reports
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• 제3권2호
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• pp.135-138
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• 2009

Cell cultures of Cayratia trifolia (Vitaceae), a tropical lianas, were maintained in Murashige and Skoog's medium containing $0.25mg\;1^{-1}$ NAA, $0.2mg\;1^{-1}$ kinetin and casein hydrolysate $250mg\;1^{-1}$. Cell suspension cultures of C. trifolia accumulate stilbenes (piceid, resveratrol, viniferin, ampelopsin), which on elicitation by any of $500{\mu}M$ salicylic acid, $100{\mu}M$ methyl jasmonate, $500{\mu}M$ ethrel and $500mg\;1^{-1}$ yeast extract, added on the 7th day, were enhanced by 3- to 6-fold ($5-11mg\;1^{-1}$) by the 15th day.