• 한국세라믹학회지
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• 제48권5호
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• pp.471-478
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• 2011

Investigations of crystal structure and phase transition of $Pb(Zr_{0.52}Ti_{0.48})O_3$ ceramics doped with A-site substitution impurity (La, Nd) or B-site substitution impurity (Sb, Nb) at 2 mol% concentration were carried out. X-ray diffraction patterns of impurities doped $Pb(Zr_{0.52}Ti_{0.48})O_3$ ceramics have been measured at pressures up to ~5 GPa with diamond anvil cell and synchrotron radiation. The patterns were obtained at room temperature using methanol-ethanol mixture as pressure-transmitting media. In order to refine the crystal structure, Rietveld analysis has been performed. The structures of impurities doped $Pb(Zr_{0.52}Ti_{0.48})O_3$ ceramics are tetragonal in space group P4mm at ambient pressure and are transformed into a cubic phase in space group Pm$\bar{3}$m as the pressure increases. In this study, when A-site substitution donor $La^{3+}$ or $Nd^{3+}$ ion was added to $Pb(Zr_{0.52}Ti_{0.48})O_3$ ceramics, the phase transition phenomena showed up at the pressure of 2.5~4.6 GPa, but when B-site substitution donor $Nb^{5+}$ or $Sb^{5+}$ ion was added to it, the phase transition appeared at relatively lower pressure of 1.7~2.6 GPa.

• 한국수정란이식학회지
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• 제30권3호
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• pp.229-237
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• 2015

To improve the developmental potential of bovine somatic cell nuclear transfer (SCNT) embryos, this study compared the developmental rates to blastocyst stage in the SCNT embryos using donor fibroblasts treated with 5-azacytidine (5AC) and S-adenosylhomocysteine (SAH) at different concentrations. Their reprogramming efficiency level was investigated with level of telomerase activity. Donor fibroblasts isolated from adult ear skin of a cow were exposed to 5AC and SAH at different concentrations during 2 passages. After nuclear transfer into enucleated recipient oocytes, the cleavage and developmental rates were significantly (p<0.05) decreased in the SCNT embryos using 5AC-treated fibroblasts (5AC-SCNT embryos), compared with those of non-treated control (control-SCNT embryos) and SAH-treated fibroblasts (SAH-SCNT embryos). The developmental rates to blastocyst stage tended to be slightly increased in the SAH-SCNT embryos at each of the concentrations, and especially, the developmental rates in the SCNT embryos using 1.0 mM SAH-treated fibroblasts were significantly (p<0.05) higher than that of control SCNT embryos. The mean numbers of total and ICM cell in blastocysts were also significantly (p<0.05) decreased in the 5AC-SCNT embryos, compared with those of other SCNT blastocysts. Further, the level of telomerase activity was also significantly (p<0.05) decreased in the 5AC-SCNT embryos than those of control and SAH-SCNT embryos. Whereas, a significantly (p<0.05) up-regulated telomerase activity was observed in SAH-SCNT embryos, compare with that of control-SCNT embryos. In conclusion, SCNT embryos using hypomethylated donor cells with SAH, not 5AC, may improve the developmental potential and reprogramming efficiency.

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2002년도 춘계학술발표대회 발표논문초록집
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• pp.40-40
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• 2002

Nuclear transfer (NT) has the potential to produce large number of identical progeny and would greatly benefit ongoing research efforts, Cloned animals produced by NT, however, may not be genetically identical to the donor cell. In NT procedures, nucleus genes originate from donor cell, and mitochondrial genes originate from recipient oocytes. (omitted)

• Asian-Australasian Journal of Animal Sciences
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• 제21권5호
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• pp.648-656
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• 2008

The objective of this study was to establish conditions for transfection of a foreign gene into somatic cells using cationic lipid reagents and to evaluate the effects of transfection on in vitro development of somatic cell nuclear transfer (SCNT) embryos. Green fluorescent protein (GFP) gene was used as a foreign gene and a non-transfected somatic cell was utilized as a control karyoplast. Monolayers of porcine cells were established and subsequently transfected with a GFP-expressing gene (pEGFP-N1) using three types of transfection reagents (LipofectAMINE PLUS, FuGENE 6 or ExGen500). Donor cells used for SCNT included transfected fetal or adult fibroblasts and oviduct epithelial cells, either serum-fed or serum-starved. Oocytes matured in vitro for 42 h were reconstructed with either transfected or non-transfected porcine somatic cells by electric fusion and activation using a single DC pulse of 1.8 kV/cm for $30{\mu}s$ in $Ca^{2+}$ and $Mg^{2+}-containing$ 0.26 M mannitol solution. Reconstructed oocytes were subsequently cultured in NCSU-23 medium for 168 h and the developmental competence and cell number in blastocyst were compared. There were no significant differences (P>0.05) in fusion, cleavage rates or development to the blastocyst stage between non-transfected, transfected, serum-fed and serum-starved cells. However, the rates of GFP-expressing blastocysts were higher in the FuGENE 6 group (71.4%) among transfection reagents and in the fetal fibroblasts group (70.4%) for donor cells. These results indicate that fetal fibroblasts transfected with FuGENE 6 can be used as donor cells for porcine SCNT and that GFP gene can be safely used as a marker of foreign genes in porcine transgenesis.

• 한국수정란이식학회지
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• 제17권2호
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• pp.101-108
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• 2002

Human Prourokinase (proUK) offers potential as a novel agent with improved fibrin specificity and, as such, may offer advantages as an attractive alternative to urokinase that is associated with clinical benefits in patients with acute peripheral arterial occlusion. For production of transgenic cow as human proUK bioreacotor, we conducted this study to establish efficient production system for bovine transgenic embryos by somatic cell nuclear transfer (NT) using human prourokinase gene transfected donor cell. An expression plasmid for human prourokinase was constructed by inserting a bovine beta-casein promoter, a green fluorescent protein (GFP) marker gene, and human prourokinase target gene into a pcDNA3 plasmid. Cumulus cells were used as donor cell and transfected with the expression plasmid using the Fugene 6 as a carrier. To increase the efficiency for the production of transgenic NT, development rates were compared between non-transfected and transfected cell in experiment 1, and in experiment 2, development rates were compared according to level of GFP expression in donor cells. In experiment 1, development rates of non-transgenic NT embryos were significantly higher than transgenic NT embryos (43.3 vs. 28.4％). In experiment 2, there were no significant differences in fusion rates (85.4 vs. 78.9％) and cleavage rates (78.7 vs. 84.4％) between low and high expressed cells. However, development rates to blastocyst were higher in low expressed cells (17.0 vs. 33.3％), and GFP expression rates in blastocyst were higher in high expressed cells (75.0 vs. 43.3％), significantly.

• Journal of Pharmaceutical Investigation
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• 제35권2호
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• pp.111-116
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• 2005

The unstirred water layer (UWL), which has been known to exist in the boundary of the intestinal lumen and intestinal wall, often behaves as an absorption barrier especially for lipophilic drugs. The intestinal absorption of drugs is often characterized using Caco-2 cell monolayers grown on Transwell polycarbonate membranes. The permeability $(P_{app})$ of drugs across the cell monolayer might be influenced by the agitation of the donor compartment, since the width of UWL on the surface of the cell monolayer would be reduced by the agitation. In this study, the effect of agitation of the donor compartment with 60 rpm on the permeability was measured for 12 drugs with a wide range of lipophilicity and permeability. The $P_{app}$ of mannitol, tributylmethyl ammonium, cimetidine, ranitidine, hydrocortisone, benzylpenicillin and loxoprofen was not influenced by the agitation, while the $P_{app}$ of theophylline, propranolol, YH439, phenylpropanolamine and testosterone was increased by the agitation. There was a significant correlation between the increase of $P_{app}$ by agitation and the lipophilicity for the compounds having $P_{app}>2{\times}10^{-5}$ cm/sec. No correlation was observed for the difference in $P_{app}$ by agitation and the molecular weight, or lipophilicity of the drugs. Therefore, the agitation rate of the donor compartment in the Caco-2 cell monolayer study should be carefully controlled in order to estimate $P_{app}$ reproducibly especially for lipophilic drugs.

• IMMUNE NETWORK
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• 제15권3호
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• pp.125-134
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• 2015

Acute graft-versus-host-disease (GVHD) is characterized by selective damage to the liver, the skin, and the gastrointestinal tract. Following allogeneic hematopoietic stem cell transplantation, donor bone marrow (BM) cells repopulate the immune system of the recipient. We previously demonstrated that the acute intestinal GVHD (iGVHD) mortality rate was higher in MyD88-deficient BM recipients than that in the control BM recipients. In the present study, the role of MyD88 (expressed by donor BM) in the pathophysiology of hepatic GVHD (hGVHD) was examined. Unlike iGVHD, transplantation with MyD88-deficient T-cell depleted (TCD) BM attenuated hGVHD severity and was associated with low infiltration of T cells into the liver of the recipients. Moreover, GVHD hosts, transplanted with MyD88-deficient TCD BM, exhibited markedly reduced expansion of $CD11b^+Gr-1^+$ myeloidderived suppressor cells (MDSC) in the liver. Adoptive injection of the MDSC from wild type mice, but not MyD88-deficient mice, enhanced hepatic T cell infiltration in the MyD88-deficient TCD BM recipients. Pre-treatment of BM donors with LPS increased MDSC levels in the liver of allogeneic wild type BM recipients. In conclusion, hGVHD and iGVHD may occur through various mechanisms based on the presence of MyD88 in the non-T cell compartment of the allograft.

• 한국미생물·생명공학회지
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• 제17권5호
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• pp.454-460
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• 1989

자연계로부터 분리한 Gram 음성세균과 함께 유전자 조작기법으로 kanamycin (Km)과 chloramphenicol (Cm)에 대한 내성유전자를 재조합한 균주들에서 그 내성유전자의 전이율을 conjugation 방법으로 몇 가지 상이한 수질환경에서 비교 연구하였다. 자연계로부터 분리한 DK1 균주와 재조합한 DKC601이나 DKH103을 donor로 하고 recipient 및 기타 조건을 같게 했을 때, donor가 가지고 있던 Km$^{${\gamma}$}$ 유전자의 전이율은 자연환경의 하천수에서 보다 실험실 환경의 멸균한 하폐수에서 더 높았고, 실험실 환경에서는 멸균한 하폐수보다 Luria-Bertani (LB) 액체배지에서 휠씬 높았다. 온도를 2$0^{\circ}C$와 3$0^{\circ}C$로 했을 때에는 어느 종류의 균주를 donor로 사용하더라도 전이율에는 큰 차이가 없었으나, 전이가 일어나는 시간은 3$0^{\circ}C$에서 조금 빨랐다. 하천수의 자연환경에서나 실험실이 멸균하폐수에서는 항생제내성유전자의 전이율은 두 가지 종류의 균주 사이에 차이가 거의 없거나 재조합된 균주에서 $10^{-1}$ 정도로 낮다. 그러나 실험실 환경의 LB액체배지에서는 전이가 일어나는데 필요한 반응시간이 재조합된 균주에서 더 길 뿐만 아니라, 전이율에 있어서도 $10^{-3}$ - $10^{-4}$ 정도 낮았다. 그리고 MT1 균주를 recipient로 하고 재조합된 균주인 DKC601과 DKH103을 donor 로 했을 경우에는 donor에 따라 전이율의 차이가 없었으나, DKC601을 donor로 하고 MT1과 MT2을 각각 recipient로 했을 경우에는 recipient에 따라 전이율이 $10^{1}$ - $10^{2}$ 정도 차이가 났다.

• Genomics & Informatics
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• 제15권1호
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• pp.2-10
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• 2017

Early detection and proper management of kidney rejection are crucial for the long-term health of a transplant recipient. Recipients are normally monitored by serum creatinine measurement and sometimes with graft biopsies. Donor-derived cell-free deoxyribonucleic acid (cfDNA) in the recipient's plasma and/or urine may be a better indicator of acute rejection. We evaluated digital PCR (dPCR) as a system for monitoring graft status using single nucleotide polymorphism (SNP)-based detection of donor DNA in plasma or urine. We compared the detection abilities of the QX200, RainDrop, and QuantStudio 3D dPCR systems. The QX200 was the most accurate and sensitive. Plasma and/or urine samples were isolated from 34 kidney recipients at multiple time points after transplantation, and analyzed by dPCR using the QX200. We found that donor DNA was almost undetectable in plasma DNA samples, whereas a high percentage of donor DNA was measured in urine DNA samples, indicating that urine is a good source of cfDNA for patient monitoring. We found that at least 24% of the highly polymorphic SNPs used to identify individuals could also identify donor cfDNA in transplant patient samples. Our results further showed that autosomal, sex-specific, and mitochondrial SNPs were suitable markers for identifying donor cfDNA. Finally, we found that donor-derived cfDNA measurement by dPCR was not sufficient to predict a patient's clinical condition. Our results indicate that donor-derived cfDNA is not an accurate predictor of kidney status in kidney transplant patients.

• 한국전기전자재료학회논문지
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• 제35권6호
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• pp.581-593
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• 2022

As energy depletion and environmental pollution problems are intensified, research has been conducted actively on alternative energy sources, an eco-friendly and continuous available energy conversion system. So has been organic solar cells whose efficiency is improved to 18.32%. The photoactive layer inside the solar cell is composed of a donor and a acceptor, and the combination of materials capable of effectively exchanging electrons greatly affects the efficiency of the organic solar cell. Accordingly, various researches have been conducted to improve the efficiency, and the maximum efficiency could be achieved by a solar cell with high carrier generation and low charge recombination characteristics through the introduction of a non-fullerene acceptor and material reconstruction. Organic solar cells are still difficult to commercialize due to their efficiency limitations and light stability, but if a photoactive layer consisting of a donor capable of efficiently absorbing long-wavelength light and an acceptor capable of forming an appropriate energy level is designed, the efficiency of the organic solar cell will reach 20%.