• Proceedings of the Korea Society of Poultry Science Conference
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• 2005.11a
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• pp.70-71
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• 2005

본 연구는 1세포기 닭 수정란에 retrovirus vector (RSV-GFP)를 도입하여 외래유전자의 핵 전이 효율을 높이고자 하였다. 실험은 polybrene과 retrovirus 혼합물을 1세포기 또는 배반엽 단계의 수정란 세포질에 미세주입하고 배양 3 또는 4일차에 GFP의 발현 양상들을관찰하였다. 실험의 결과는 배반엽 수정란에서 GFP발현을 관찰할 수 있었으나, 1세포기 수정란에서는 GFP의 발현을 관찰할 수 없었다. 연구결과는 형질전환닭 생산에 있어서 가장 효율적인 방법은 배반엽 단계에 retrovirus를 미세주입하는 방법임을 보여주고 있다.

• Proceedings of the KSLP Conference
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• 1993.12a
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• pp.18-18
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• 1993

성문폐쇄부전의 개선을 위해 후두내에 주입하여온 여러 재료 중 현재에는 teflon만이 가장 흔히 사용되어지고 있다. 그러나 teflon은 점막하와 가동성 성대 내에 주입할 수 없어 경도 성문 폐쇄부전의 미세 조정과 성대의 작은 결손에는 부적합하다. 성문폐쇄부전을 개선하기 위하여 9명의 환자에서 17회 cross-linked collagen을 주입한 결과 이 방법은 환자의 음성을 개선하고 성문폐쇄부전을 교정하는데 성공적이었다. (중략)

• Korean Journal of Animal Reproduction
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• v.20 no.1
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• pp.19-26
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• 1996

In the present study, we investigated devel-opmental ability and transgene expression of IVM/IVF derived porcine embryos following microinjection with SV40-LacZ. A total of 412 IVM/IVF derived embryos were used to examine developmental ability and transgene expression following DNA microinjection. After centrifugation, pronuclei were visible in 60.3% when examined between 18~21h after IVF. Development and transgene expression were assessed after 9 days in culture. The percentages of injected embryos reaching to the morula and blastocyst were significantly lower (P<0.05) than those of non-injected control embryos. However, the percentages of DNA microinjected embryos and non-injected embryos that developed to the blastocyst or hatched blastocyst stage in dual culture systems (NCSU23 and EMEM) were significantly higher (P<0.05) than those in NCSU23 medium alone. As the resuIt of X-gal staining, the proportion of positive embryos was 40~43% in morula and blastocyst stage embryos, however, mosaicism has been observed in the most putative transgenic morulae and blastocysts. In the PCR analysis, the percentages of embryos integrated gGH gene were 45.0 and 44.4% in morula and blastocyst stage, respectively. These results suggest that improved IVM /IVF system and culture condition increased the embryo viability and ex-pression of a microinjected transgene.

• 대한미세수술학회:학술대회논문집
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• 1994.11a
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• pp.102.2-103
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• 1994

• Proceedings of the Korea Society of Poultry Science Conference
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• 2000.11a
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• pp.73-74
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• 2000

• Analytical Science and Technology
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• v.7 no.4
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• pp.527-540
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• 1994

The surface microstructure modification by $N^+ion$ implantation into 7050A1 alloy was investigated. Ion implantation method is to implant physically accelerated ions to the surface of a substrate. High doses of nitrogen($5{\times}10^{15}ions/cm^2$, $5{\times}10^{17}ions/cm^2$, $8{\times}10^{17}ions/cm^2$) were implanted into 7050A1 alloy using accelerating voltage of 100KeV and current density of $23.1{\mu}A/cm^2$. The implanted layers were characterized by EPMA, AES, XRD, and TEM. The experimental results were compared with computer simulation data. The results showed that AlN was formed from the surface to $4000{\AA}$ depth with Gaussian distribution and the damage region was also observed. This surface modification by $N^+ion$ implantation increased the microhardness of 7050A1 alloy surface.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.1
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• pp.89-95
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• 2012

In this paper, microchannels for the flow control of two fluids with different volumes have been designed, fabricated, and verified. The dimensions of the inlets were determined based on the Stokes equation in order to realize that the flow of the two fluids meet at the same time, and to maintain a certain configuration when the flows passed through each inlet channel. The designed microchannels were confirmed using computational fluid dynamics simulation for the incompressible, Newtonian, and transient flows. In addition, a microfluidic system containing the designed microchannels was fabricated by soft lithography, and the pressure-driven flows of the two fluids were characterized by microfluidic experiments.

• Journal of Life Science
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• v.27 no.12
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• pp.1445-1451
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• 2017

Mitochondria play a central role in energy generation by using electron transport coupled with oxidative phosphorylation. They also participate in other important cellular functions including metabolism, apoptosis, signaling, and reactive oxygen species production. Therefore, mitochondrial dysfunction is known to contribute to a variety of human diseases. Furthermore, there are various inherited diseases of energy metabolism due to mitochondrial DNA (mtDNA) mutations. Unfortunately, therapeutic options for these inherited mtDNA diseases are extremely limited. In this regard, mitochondrial replacement techniques are taking on increased importance in developing a clinical approach to inherited mtDNA diseases. In this study, green fluorescence protein (GFP)-tagged mitochondria were isolated by differential centrifugation from a mammalian cell line. Using microinjection technique, the isolated GFP-tagged mitochondria were then transferred to bovine oocytes that were triggered for early development. During the early developmental period from bovine oocytes to blastocysts, the transferred mitochondria were observed using fluorescent microscopy. The microinjected mitochondria were dispersed rapidly into the cytoplasm of oocytes and were passed down to subsequent cells of 2-cell, 4-cell, 8-cell, morula, and blastocyst stages. Together, these results demonstrate a successful in vitro transfer of isolated mitochondria to oocytes and provide a model for mitochondrial replacement implicated in inherited mtDNA diseases and animal cloning.

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.5
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• pp.86-93
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• 2021

In order to remove particulate matter, functional construction materials are developed. However, there is no evaluation method and infrastructure for particulate matter removal rate. Therefore, the purpose of this study was to build a particulate matter removal rate test chamber and to present a method for particulate matter removal rate. As a result, since construction materials have effectiveness in an environment where particulate matter is generated, the particulate matter injection step was proposed as a comparison target. The evaluation of the particulate removal rate was proposed by relative comparison of the slope values obtained by linear regression analysis for all concentration values measured in the particulate matter injection step. In linear regression method, all measured values can be evaluated, and the variability can be evaluated with the coefficient of determination (R-square), so that the reliability of the particulate matter removal rate can be secured.

• Clinical and Experimental Reproductive Medicine
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• v.25 no.3
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• pp.331-340
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• 1998

We determined the incidence of activation, male pronuclear formation and apposition of pronuclei in porcine oocytes following intracy-toplasmic injection of various porcine sperm components and foreign species spermatozoa, such as mouse, human or cattle. The porcine oocytes were activated by injection of a spermatozoon or an isolated sperm head. Neither isolated sperm tail nor perinuclear material removed sperm head activated oocytes. Because injection of mouse, bovine or human spermatozoon activated porcine oocytes, the sperm born activation factors is not strict species specific. Male pronuclear formation and pronuclear apposition were observed in the porcine oocytes following injection of porcine, bovine, mouse or human spermatozoa. The electrical stimulation following sperm cell injection did not enhance the incidence of male pronuclear formation nor pronuclear apposition comparent with sperm cell injection alone (p>0.1). Mitosis and two cell division in some oocytes were observed at 20 to 24 h after injection of porcine spermatozoon. However, none of oocytes following injection of mouse, bovine or human spermatozoa developed to the mitotic metaphase or normally divided to the two cell stage. These results suggested that the oocyte activating factor(s) presented in the perinuclear material and it is not species specific for the porcine oocyte.