• 식물조직배양학회지
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• 제26권2호
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• pp.99-102
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• 1999

Glucose - induced arginine transport system was induced by a exogenous application of NH$_4$^+ ion. The uptake rate of arginine (Arg) depended on the external NH$_4$^+ ion concentration. The uptake rate was inhibited by the presence of NH$_4$^+ ion within 1 min, whereas it increased maximally after 30 min. Glucose and NH$_4$^+ ion induced the same arginine transport system. Km value of Arg transport systems was 2 $\mu$M, and V_(max) was 60 $\mu$mol^(-1) . h . g fresh weight^(-1) for NH$_4$^+ ion and 174 $\mu$mol^(-1) . h . g fresh weight^(-1) for glucose induced transport system. But, the transport system of Glu for glucose and NH$_4$^(-1) ion induced had different Km values. Km value of Glu was 285 $\mu$M for glucose - and 58 $\mu$M for NH$_4$^+ ion induced transport system. Thus, NH$_4$^+ ions play a important role as inducer for the glutamine transport system. NH$_4$^+ ion induced glutamine system was inhibited over 90% by cycloheximide. We concluded that a new carrier protein for glutamine was induced by NH$_4$^+ ion.

• 한국산림과학회지
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• 제98권5호
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• pp.513-523
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• 2009

Many species, cultivars, and hybrids in Populus have been introduced and developed by the scientists of Department of Forest Genetic Resources, Korea Forest Research Institute in Korea. P. alba ${\times}$ glandulosa, P. euramericana, P. nigra ${\times}$ maximowiczii, P. koreana ${\times}$ P. nigra var. italica, and P. davidiana have been studied from many aspects, i.e., genetics, breeding, physiology, propagation, silviculture, biomass production, biotechnology and phytoremediation. These precedent results will provide a sound basis for a newly-arising research on short-rotation coppice as one of renewable resources and phytoremediation plants. It was found that there were many promising varieties and clones for these purposes. However, minute analysis on specific gravity and caloric values for those plants should be followed under several silvicultural and rotational systems.

• KSBB Journal
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• 제9권3호
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• pp.294-298
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• 1994

$CaCl_2$, glucose, frutose, glutamine, glutamate 그리고 Ii pids와 같은 배지 첨가물들이 회분식 그리고 연속식 2단계 생물반응기 시스템에셔 재조합 ${\beta}$-galactosidase (${\beta}$-gal) 생산을 증진시키는가를 조사하였다. Sf 21 세포에 AcNPV의 감염시 $CaCl_2$, frutose, glutamate, cholesterol 및 tocoph eral과 같은 배지 첨가물을 첨가하였을 때 ${\beta}$-gal 생산이 증진되었다. 30mM $CaCl_2$, 2.2mM frutose, 4.lmM glutamine, 그리고 O.34mM cholesterol이 보강된 감염 배 지를 이용한 재조합${\beta}$-gal 생산은 약 40% 의 증가를 보였다.

• KSBB Journal
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• 제5권2호
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• pp.119-124
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• 1990

다중 교반형 생물반응기 내에서 배추 PLD에 의한 인 지방질의 염기 가수분해 반응 및 염기전이 반응에 대한 특성 실험에서 다음과 같은 결론을 얻었다. 반응 최적 조건으로서 pH 5.6, 온도 37$^{\circ}C$였고 반응 촉진제로서 $Ca^2^+$의 농도는 가수분해 반응시 20mM, 염기전이 반응에서는 40mM이었다. Diethylether와 butylacetate도 강력한 반응촉진제로서 반응성을 높였고 이들의 농도는 20%가 효과적이었으며, 반면에 EDTA 및 $Ba^2^+,Mn^2^+,Zn^2^+$등은 PLD의 활성을 강력하게 저해하였다, 염기 수용체로서 glycerol을 비롯한 알콜 화합물은 대부분이 반응성을 양성으로 나타내었으며 15종의 알콜 화합물 가운데 glycerol, ethyleneglycol, propyleneglycol등이 반응성이 높게 나타났으며 이들의 최적농도는 20%가 효과적이었다.

• KSBB Journal
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• 제28권1호
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• pp.24-30
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• 2013

Dissolved oxygen, pH and cell concentration have been online monitored in cultivation processes with Escherichia coli by using a $MABOOMS^{TM}$ (microplate-based bioreactor with optical online monitoring systems). Fluorescent sensing membranes containing Ru ${(dpp)_3}^{2+}$ or HPTS were prepared with GA sol-gel matrix and coated into a well of a 24-well microplate. Fluorescence intensity was measured and correlated to the dissolved oxygen or pH. Cell concentrations were also online monitored by measuring optical reflectance at 650 nm. A well of a 24-well microplate could also be divided into 4 parts, each of which was coated with fluorescent sensing membranes for the detection of dissolved oxygen or pH. The 24-well microplate coated with fluorescent sensing membranes or a 4-divided sensing membrane. was used to online monitor the dissolved oxygen, pH and cell concentration during E. coli cultivations. The online monitoring results showed the characteristics of cell growth in cultivation processes very well.

• BMB Reports
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• 제41권8호
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• pp.575-580
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• 2008

Thymocyte-specific transcriptional regulatory systems can be used to better understand the relationship between transcription and V(D)J recombination during early T cell development. In this study, we generated transgenic mice expressing the transactivator Gal4-VP16 or the Gal4 DNA binding domain (Gal4-DBD) under the control of the lck proximal promoter, which is only active in immature thymocytes. From these studies Gal4-VP16 and Gal4-DBD expression was shown to significantly alter thymic cellularity and differentiation without significantly changing the $CD3^+$ thymocyte distribution. Furthermore, the presence of Gal4-VP16 or Gal4-DBD in the transgenic thymocytes retarded the mobility of the Gal4 DNA binding motif as determined by a gel mobility shift assay, suggesting that the developmental alteration did not affect the functional property of the transgenic proteins. These results indicated that lck promoter-driven Gal4-VP16 or Gal4-DBD expression did not affect $CD3^+$ mature thymocytes, thus this system can be applied to study transcriptional regulation of transresponder genes in bigenic mouse model thymocytes.

• Animal cells and systems
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• 제14권4호
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• pp.343-349
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• 2010

Ultrastructural studies of vitellogenesis in oocytes and follicle cells during oogenesis in female Protothaca (Notochione) jedoensis were investigated by histological and transmission electron microscope observations. In early vitellogenic oocytes, combined activities of the Golgi complex, mitochondria and rough endoplasmic reticulum in the cytoplasm are associated with autosynthetic vitellogenesis. Furthermore, at this time, many coated vesicles at the basal region of the oolemma of the oocyte lead to the formation of vesicles through endocytosis in the cytoplasm. Through the formation of the coated pits on oolemma during vitellogenesis, the uptake of extrafollicular precursors (nutritive materials) occurs in coated vesicles by endocytosis. Therefore, it is assumed that these exogenous materials are involved in heterosynthetic vitellogenesis. During late oogenesis, exogenous yolk precursors (yolk granules), lipid droplets and proteinaceous yolk granules are present in the cytoplasm of late vitellogenic oocytes. In mature oocytes, small yolk granules appear intermingled and form large mature yolk granules. Thus, two processes of vitellogenesis occur in oocytes by way of endogenous autosynthesis and exogenous heterosynthesis. The follicle cells attached to the oocytes appear to play an integral role in vitellogenesis in this study.

• 설비공학논문집
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• 제19권1호
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• pp.86-93
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• 2007

The PEM (polymer electrolyte membrane) fuel cell is one of the promising fuel cell systems as a new small power generating device for automobiles and buildings. The optimal design of cooling plates installed between MEA (membrane electrode assembly) is very important to achieve high performance and reliability of the PEMFC because it is very sensitive to temperature variations. In this study, six types of cooling plate models for the PEMFC including basic serpentine and parallel shapes were designed and their cooling performances were analyzed by using three-dimensional fluid dynamics with commercial software. The model 3 designed by revising the basic serpentine model represented the best cooling performance among them in the aspect of uniformity of temperature distribution and thermal reliability, The serpentine models showed higher pressure drop than the parallel models due to a higher flow rate.

• 산업경영시스템학회지
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• 제31권4호
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• pp.77-85
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• 2008

생물학적인 셀 인젝션 기술은 유전자 주입, 시험관 배양, 인공수정 및 신약개발 분야에서 광범위하게 사용되어 오고 있는 기술이다. 생물공학에서 다루는 셀 인젝션 기술은 크게 착생세포 인젝션과 서스펜디드 셀 인젝션으로 구분할 수 있다. 최근 상용화 장비로 출시되고 있는 것들은 착생세포에 대한 자동 인젝션 시스템이 대부분을 차지하고 있다. 반면, 서스펜디드 셀 인젝션 시스템의 경우는 비교적 최근들어 자동화 장비 및 방법론의 개발에 대한 논의가 이루어지고 있는 실정으로 실제 수많은 연구자들의 노력에 힘입어 서스펜디드 셀을 대상으로 한 통합 자동화 셀 인젝션 시스템의 개발이 가속화되고 있기는 하지만 이에 대한 만족할 만한 성과는 아직 이루어 지지 않고 있는 실정이다. 본 논문은 서스펜디드 셀을 대상으로 한 인젝션 시스템 개발에 관한 것으로 특히 셀 홀딩 시스템과 최적의 인젝션 피펫 궤적을 결정하기 위한 시스템 개발에 관한 것이다. 본 논문에서 다루어지는 서스펜디드 셀은 통합 자동화를 위하여 특별히 고안된 셀홀딩 시스템에 의하여 배열의 형태로 고정되며, 셀 인젝션 시스템은 엠브리오와 인젝션 피켓을 이미지 프로세싱 기술에 의하여 인식하고 피펫의 인젝션 궤적을 결정하는 것을 포함하고 있다.

• KSBB Journal
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• 제15권5호
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• pp.497-500
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• 2000

Avidin의 금속표변에 대한 강한 결합력과 avidin-biotin의 강한 결합력을 이용하여 금속 표면 위에 라포좀과 같은 유기 분자막의 다층 형성 과정을 수정진동자를 이용하여 분석하였다. 금속 표변위에 적층되는 유기 분자막에 대한 정보를 수 집하고 그 가능성을 검토하여 바이오 센서에서 감도를 향상 시킬 수 있는 새로운 방법을 제시하고자 하였다.