• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 C
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• pp.1156-1158
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• 1998

This paper Presents two distribution-feeder models to simplify complicated distribution system calculations. These equivalent models are developed to simulate the total series voltage drop at the end of the given feeder and the total line loss of the given feeder accurately. In addition, the proposed models are bidirectional. This means that power infeed can be at either end and the model is accurate. Also, it is shown that the proposed models are suitable for network reconfiguration.

• 식물조직배양학회지
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• 제24권5호
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• pp.295-303
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• 1997

Japonica 벼 품종 Taipei 309 성숙 종자의 배반에서 유도된 캘러스로부터 유기 시킨 세포 현탁 배양체에서 원형질체를 분리하여 filter membrane과 feeder 세포를 이용한 여러가지 조건에서 배양하였다. 이러한 조건들은 gelling agents, feeder 세포와 원형질체 밀도, feeder 세포의 종류 및 heat shock 처리 등이며 이들이 filter membrane 배양 방법에서 원형질체 평판 효율에 미치는 효과들을 조사하였다. 원형질체 평판 효율은, Lolium multiflorum을 feeder 세포로 사용하고 (10 mL의 원형질체 배양 배지당 0.5 mL pcv) 원형질체를 mL 당 $5\;\times\;10^{5}$개로 하여 Sea Plague agarose 배지에 원형질체를 배양 했을때 최고치를 얻었다. 원형질체에 heat shock 처리를 했을 때 원형질체 평판 효율은 변화가 없었다. carbohydrate source로서 sucrose로서 sucrose 대신에 maltose를 사용했을 때 식물체 재분화율이 높았으며 원형질체로부터 재분화된 이들 식물체들은 임성을 나타내었다.

• 식물조직배양학회지
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• 제25권2호
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• pp.81-88
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• 1998

Southeast Asian javanica 벼 품종 Tinawen의 진탕 배양세포로부터 나출된 원형질체의 효과적인 배양과 식물체 재분화가 조사되었다. Lolium multiforum과 Oryza ridleyi의 진탕 배양세포들을 feeder cell로 사용했고 여러가지 재분화 배지를 이용하여 원형질체로부터 유도된 colony들을 재분화 시켰으며, 또한 식물체 재분화율을 높히기 위해 원형질체로 부터 유도된 colony들을 dehydration 시켜 재분화율을 조사하였다. L multiflorum 또는 O. ridleyi의 진탕 배양세포들을 feeder cell로 사용했을 때 원형질체의 평판효율은 feeder cell type과 age에 따라 차이가 났지만 0.09%에서 1.48% 범위로 나타났고, L. multiflorum을 feeder cell로 사용했을 때가 O. ridleyi cell을 사용했을때 보다 6배 높게 원형질체 평판효율을 얻었다. Feeder cell로 L. multiflorum을 사용하여 배양된 원형질채로부터 유도된 colony들을 dehydration 시킨 경우는 19.3-31.7%, O. ridleyi을 사용한 경우는 13.0-18.0%, 또한 이들 두 진탕 배양세포들을 혼합한 것을 사용한 경우는 18.0-22.0%의 식물체 재분화율을 얻은 반면에, dehydration을 시키지 않았을 때는 각각 2.0-7.0%, 3.0-5.0%, 0-4.0%의 재분화율을 얻었다. 원형 질체에서 재분화된 식물체의 flow cytometry를 이용한 배수성 분석 결과 대부분의 식물체가 이배체로 나타난 반면, 단지 34개중 두 식물체에서만이 4배체로 나타났다. 재분화된 식물체들은 온실에 옮겨 기른 결과 정상적인 임성을 나타내었다.

• 한국발생생물학회지:발생과생식
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• 제12권2호
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• pp.141-149
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• 2008

This study was conducted to develop an efficient cryopreservation method of human embryonic stem (ES) cells using vitrification. In an initial experiment, sub-clumps of human ES cells (CHA-hES3 and CHA-hES4) were vitrified using grids after incubation with STO feeder cells for 1 or 16 h (Groups 1-1 and 1-2, respectively). After storage for $2{\sim}4$ months, thawed clumps were re-plated on a fresh feeder layer. The survival rates of warmed CHA-hES3 and CHA-hES4 cells of Group 1-2 were significantly higher than those of the corresponding Group 1-1 cells. In the second experiment, human ES cells were vitrified after incubation with feeder or feeder-conditioned medium (Groups 2-1 to -7). Relative mRNA expression of BM proteins and survival rates were increased following incubation of ES cells with fresh feeder cells for 16 h. In conclusion, increasing of tight adhesion between ES cells by extended incubation with feeder could reduce cryoinjury after vitrifying/warming.

• 한국발생생물학회지:발생과생식
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• 제19권3호
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• pp.119-126
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• 2015

The suitable feeder cell layer is important for culture of embryonic stem (ES) cells. In this study, we investigated the effect of two kinds of the feeder cell, MEF cells and STO cells, layer to mouse ES (mES) cell culture for maintenance of stemness. We compare the colony formations, alkaline phosphatase (AP) activities, expression of pluripotency marker genes and proteins of D3 cell colonies cultured on MEF feeder cell layer (D3/MEF) or STO cell layers (D3/STO) compared to feeder free condition (D3/-) as a control group. Although there were no differences to colony formations and AP activities, interestingly, the transcripts level of pluripotency marker genes, Pou5f1 and Nanog were highly expressed in D3/MEF (79 and 93) than D3/STO (61and 77) or D3/- (65 and 81). Also, pluripotency marker proteins, NANOG and SOX-2, were more synthesized in D3/MEF ($72.8{\pm}7.69$ and $81.2{\pm}3.56$) than D3/STO ($32.0{\pm}4.30$ and $56.0{\pm}4.90$) or D3/- ($55.0{\pm}4.64$ and $62.0{\pm}6.20$). These results suggest that MEF feeder cell layer is more suitable to mES cell culture.

• Molecules and Cells
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• 제41권7호
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• pp.631-638
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• 2018

Spermatogonial stem cells (SSCs) derived from mouse testis are unipotent in regard of spermatogenesis. Our previous study demonstrated that SSCs can be fully reprogrammed into pluripotent stem cells, so called germline-derived pluripotent stem cells (gPS cells), on feeder cells (mouse embryonic fibroblasts), which supports SSC proliferation and induction of pluripotency. Because of an uncontrollable microenvironment caused by interactions with feeder cells, feeder-based SSC reprogramming is not suitable for elucidation of the self-reprogramming mechanism by which SSCs are converted into pluripotent stem cells. Recently, we have established a Matrigel-based SSC expansion culture system that allows longterm SSC proliferation without mouse embryonic fibroblast support. In this study, we developed a new feeder-free SSC self-reprogramming protocol based on the Matrigel-based culture system. The gPS cells generated using a feeder-free reprogramming system showed pluripotency at the molecular and cellular levels. The differentiation potential of gPS cells was confirmed in vitro and in vivo. Our study shows for the first time that the induction of SSC pluripotency can be achieved without feeder cells. The newly developed feeder-free self-reprogramming system could be a useful tool to reveal the mechanism by which unipotent cells are self-reprogrammed into pluripotent stem cells.

• 한국동물생명공학회지
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• 제35권1호
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• pp.86-93
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• 2020

The establishment of porcine embryonic stem cells (ESCs) from porcine somatic cell nuclear transfer (SCNT) blastocysts is influenced by in vitro culture day of porcine reconstructed embryo and feeder cell type. Therefore, the objective of the present study was to determine the optimal in vitro culture period for reconstructed porcine SCNT embryos and mouse embryonic fibroblast (MEF) feeder cell type for enhancing colony formation efficiency from the inner cell mass (ICM) of porcine SCNT blastocysts and their outgrowth. As the results, porcine SCNT blastocysts produced through in vitro culture of the reconstructed embryos for 8 days showed significantly increased efficiency in the formation of colonies, compared to those for 7 days. Moreover, MEF feeder cells derived from outbred ICR mice showed numerically the highest efficiency of colony formation in blastocysts produced through in vitro culture of porcine SCNT embryos for 8 days and porcine ESCs with typical ESC morphology were maintained more successfully over Passage 2 on outbred ICR mice-derived MEF feeder cells than on MEF feeder cells derived from inbred C57BL/6 and hybrid B6CBAF1 mice. Overall, the harmonization of porcine SCNT blastocysts produced through in vitro culture of the reconstructed embryos for 8 days and MEF feeder cells derived from outbred ICR mice will greatly contribute to the successful establishment of ESCs derived from porcine SCNT blastocysts.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 춘계학술대회 논문집
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• pp.353-354
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• 2012

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2013년도 춘계학술대회 논문집
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• pp.103-104
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• 2013

• Journal of Electrical Engineering and Technology
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• 제10권1호
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• pp.8-17
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• 2015

This paper analyses the power flow of a three-feeder/multi-bus distribution system by a custom Generalized Power Quality Conditioner (GUPQC). The GUPQC has been realized by three voltage source converters (VSCs) coupled back-to-back through a common DC-link capacitor on the DC-side. One feeder was controlled by the shunt compensator, whereas each of the other two feeders was controlled by the proposed novel series compensator. The GUPQC has the capability to simultaneously compensate voltage and current quality problems of a multi-bus/three-feeder distribution system. Besides that, the power can be transferred from one feeder to other feeders to compensate for poor power quality problems. Extensive simulation studies were carried out by using MATLAB/SIMULINK software to establish the ability of the GUPQC to improve power quality of the distribution systems under distorted supply voltage conditions.