• 한국수정란이식학회지
• /
• 제33권3호
• /
• pp.129-137
• /
• 2018

Acute vascular rejection has been known as a main barrier occurring in a xenograted tissue of alpha 1,3-galactosyltransferase knock-out (GalT KO) pig into a non-human primate (NHP). Adenosine which is a final metabolite following sequential hydrolysis of nucleotide by ecto-nucleotidases such as CD39 and CD73, act as a regulator of coagulation, and inflammation. Thus xenotransplantation of CD39 and CD73 expressing pig under the GalT KO background could lead to enhanced survival of recipient NHP. We constructed a human CD39 and CD73 expression cassette designed for endothelial cell-specific expression using porcine Icam2 promoter (pIcam2-hCD39/hCD73). We performed isolation of endothelial cells (pAEC) from aorta of 4 week-old GalT KO and membrane cofactor protein expressing pig ($GalT^{-MCP/-MCP}$). We were able to verify that isolated cells were endothelial-like cells using immunofluorescence staining analysis with von Willebrand factor antibody, which is well known as an endothelial maker, and tubal formation assay. To find optimal condition for efficient transfection into pAEC, we performed transfection with GFP expression vector using four programs of nucleofection, M-003, U-023, W-023 and Y-022. We were able find that the program W-023 was optimal for pAEC with regard to viability and transfection efficiency by flow cytometry and fluorescent microscopy analyses. Finally, we were able to obtain $GalT^{-MCP/-MCP}/CD39/CD73$ pAEC expressing CD39 and CD73 at levels of 33.3% and 26.8%, respectively. We suggested that pACE isolated from $GalT^{-MCP/-MCP}$ pig might be provided as a basic resource to understand biochemical and molecular mechanisms of the rejections and as an alternative donor cells to generate $GalT^{-MCP/-MCP}/CD39/CD73$ pig expressing CD39 and CD73 at endothelial cells.

• 한국세라믹학회지
• /
• 제33권11호
• /
• pp.1260-1266
• /
• 1996

The effects of SiO2 MnO2 and sintering atmospheres (O2, N2) on the piezoelectric properties and densification behaviors of Pb0.98Cd0.02Zr0.36Ti0.39Ni0.083Nb0.167O3 were investigated. The addition of SiO2 to the system enhanced the rate of densification but supressed the rate of grain growth. On the other hand the addition of MnO2 to the system did not nearly affect the rate of densification but increased slightly the rate of grain growth The densification of Pb0.98Cd0.02Zr0.36Ti0.39Ni0.083Nb0.167O3 containing of SiO2 or MnO2 was promoted with increasing the partial pressure of O2. The relative dielectric constant ($\varepsilon$r) and piezoelectric constant (d33) of Pb0.98Cd0.02Zr0.36Ti0.39Ni0.083Nb0.167O3 containing of SiO2 or MnO2 sintered under O2 atmosphere were higher than under N2 atmosphere. Whereas the mechanical quality factor (Qm) of specimens sintered under O2 atmosphere were lower than under N2 atmosphere. Thus the sintering atmosphere of O2 and N2 in Pb0.98Cd0.02Zr0.36Ti0.39Ni0.083Nb0.167O3 containing of SiO2 or MnO2 acted as donor and acceptor respectively. As the amount of SiO2 increased the relative dielectric constant ($\varepsilon$r) and piezoelectric constant (d33) of Pb0.98Cd0.02Zr0.36Ti0.39Ni0.083Nb0.167O3 but the mechanical quality factor (Qm) did not nearly change, In the case of the addition of MnO2 to the system the relative dielectric constant ($\varepsilon$r) and piezoelectric constant (d33) of Pb0.98Cd0.02Zr0.36Ti0.39Ni0.083Nb0.167O3 sintered under O2 atmosphere decreased rapidly with increasing the amount of MnO2 but they were unchanged with increasing the amount of MnO2 under N2 sintering atmosphere. Therefore the differences of the relative dielect-ric constant ($\varepsilon$r) and piezoelectric constant (d33) due to sintering atmosphere were diminished as the amount of MnO2 increased.

• 대한화학회지
• /
• 제40권1호
• /
• pp.44-49
• /
• 1996

카드뮴-113 NMR을 이용하여 수용액속에서 카드뮴 이온과 유기산(아세트산, 벤조산 및 프로판산)과의 결합 특성을 알아보았고 여기서 얻어진 결과를 폴리아크릴산(PAA)의 결합자리의 특성연구에 응용하였다. 유기산에 결합된 카드뮴 화합물의 카드뮴-113 NMR 화학적이동 결과 분석으로부터, $CDL^+$와 $CDL_2$(L:카르복실기) 화학종에 해당하는 화학적이동값은 각각 -22에서 -24ppm과 -39에서 -40ppm의 범위를 나타냈다. 카드뮴과 폴리아크릴산 화합물에서는 폴리아크릴산 대 카드뮴의 농도비를 12에서 118eq/mol로 증가시킬 때 화학적 이동값이 -36.6ppm에서 -38.2ppm으로 변하였다. 또한, 폴리아크릴산 대 카드뮴의 농도비를 고정시키고 ([PAA]/[Cd] = 39ep/mol) 용액의 pH를 1에서 6까지 변화시킬 때 화학적이동값은 1.6ppm에서 -37.6ppm으로 변하였다. 이 결과는 폴리아크릴산 대 카드뮴의 농도비 변화 실험에서 주화학종은 1:2 착물($CdL_2$)이고 농도비가 증가하면 1:2 착물형성도 증가하는 것을 보여준다.또한, 낮은 pH에서는 1:1착물($CdL^+$)이 우세하고 pH가 증가하면서 1:2 착물($CdL_2$)이 증가한다는 것을 알 수 있었다.

• 한국음향학회지
• /
• 제22권5호
• /
• pp.388-402
• /
• 2003

In this paper, we carried out the word, 4 continuous digits. continuous, and task-independent word recognition experiments to verify the effectiveness of the re-defined phoneme-likely units (PLUs) for the phonetic decision tree based HM-Net (Hidden Markov Network) context-dependent (CD) acoustic modeling in Korean appropriately. In case of the 48 PLUs, the phonemes /ㅂ/, /ㄷ/, /ㄱ/ are separated by initial sound, medial vowel, final consonant, and the consonants /ㄹ/, /ㅈ/, /ㅎ/ are also separated by initial sound, final consonant according to the position of syllable, word, and sentence, respectively. In this paper. therefore, we re-define the 39 PLUs by unifying the one phoneme in the separated initial sound, medial vowel, and final consonant of the 48 PLUs to construct the CD acoustic models effectively. Through the experimental results using the re-defined 39 PLUs, in word recognition experiments with the context-independent (CI) acoustic models, the 48 PLUs has an average of 7.06%, higher recognition accuracy than the 39 PLUs used. But in the speaker-independent word recognition experiments with the CD acoustic models, the 39 PLUs has an average of 0.61% better recognition accuracy than the 48 PLUs used. In the 4 continuous digits recognition experiments with the liaison phenomena. the 39 PLUs has also an average of 6.55% higher recognition accuracy. And then, in continuous speech recognition experiments, the 39 PLUs has an average of 15.08% better recognition accuracy than the 48 PLUs used too. Finally, though the 48, 39 PLUs have the lower recognition accuracy, the 39 PLUs has an average of 1.17% higher recognition characteristic than the 48 PLUs used in the task-independent word recognition experiments according to the unknown contextual factor. Through the above experiments, we verified the effectiveness of the re-defined 39 PLUs compared to the 48PLUs to construct the CD acoustic models in this paper.

• 한국식품위생안전성학회지
• /
• 제17권3호
• /
• pp.146-151
• /
• 2002

2001년 1-12월 서울시 가락농수산물시장에서 총 951건의 수산물(어류 34종 468건, 패류 17종 373건, 갑각류 10종 39건 그리고 두족류 등 11종 71건)을 대상으로 중금속 함량[average(minimum∼maximum), Unit:mg/kg]을 분석한 결과, Hg 0.025(N.D.∼0.19), Cd 0.288(N.D.∼l.85), Pb 0.227(ND∼l.68)이었다. Hg의 경우, 패류[0.033(N.D.∼0.19)]>두족류 등[0.026N.D.∼0.11)]>갑각류[0.026(N.D.∼0.09)]>어류[0.018(N.D.∼0.19)]순이었고, 가장 높은 함량은 미꾸라지 (0.19)와 꼬막(0.19)이었으며, Pb의 경우 패류[0.223(N.D.∼1.38)]>어류[0.213(N.D.∼1.68)]>두족류 등 [0.151(N.D.∼0.39)]>갑각류[0.144(N.D.∼0.44)]순이었고, 가장 높은 함량은 미꾸라지 (1.68)>빙어(1.44)>바지락(1.38)>뱀장어(1.35) 순이었다. 한편, Cd의 경우 패류[0.288(N.D.∼1.85)] 중 가장 높은 함량은 꼬막(1.85)이었다.

• IMMUNE NETWORK
• /
• 제13권1호
• /
• pp.25-29
• /
• 2013

Ribavirin is an antiviral drug used in combination with pegylated interferon-${\alpha}$ (IFN-${\alpha}$) for the treatment of hepatitis C virus (HCV) infection. Recently, ribavirin was reported to inhibit the suppressive activity of regulatory T (Treg) cells. In the present study, we re-evaluated the effect of ribavirin on $CD4^+$ $CD4^+$ $CD25^+$ Treg cells from normal donors. First, we examined the expression of CTLA-4 and CD39, which are known to play a role in the suppressive function of Treg cells. We found that ribavirin treatment did not modulate the expression of CTLA-4 and CD39 in Treg cells. We also studied the effect of ribavirin on Treg cells in the presence of IFN-${\alpha}$; however, the expression of CTLA-4 and CD39 in Treg cells was not changed by ribavirin in the presence of IFN-${\alpha}$. Next, we directly evaluated the effect of ribavirin on the suppressive activity of Treg cells in the standard Treg suppression assay, by co-culturing CFSE-labeled non-Treg $CD4^+$ T cells with purified Treg cells. We found that ribavirin did not attenuate the suppressive activity of Treg cells. Taken together, while ribavirin reversed Treg cell-mediated suppression of effector T cells in the previous study, we herein demonstrate that ribavirin does not impair the suppressive activity of Treg cells.

• 약학회지
• /
• 제39권4호
• /
• pp.380-384
• /
• 1995

The isoelelectric points of Cd-BP(l) and Cd-BP(II), cadmium-binding proteins, were 6.01 and 5.35, respectively. Both of them contained zinc. As for the amino acid composition, Cd-BP(I) contained a lot of glycine and lysine but none of such aromatic amino acids as tyrosine and phenylalanine.. On the other hand, Cd-BP(II) contained leucine, histidine, asparti cacid and alanine but no aromatic amino acids.

• 한국동물생명공학회지
• /
• 제39권1호
• /
• pp.48-57
• /
• 2024

Background: Cadmium (Cd) is toxic heavy metal that accumulates in organisms after passing through their respiratory and digestive tracts. Although several studies have reported the toxic effects of Cd exposure on human health, its role in embryonic development during preimplantation stage remains unclear. We investigated the effects of Cd on porcine embryonic development and elucidated the mechanism. Methods: We cultured parthenogenetic embryos in media treated with 0, 20, 40, or 60 µM Cd for 6 days and evaluated the rates of cleavage and blastocyst formation. To investigate the mechanism of Cd toxicity, we examined intracellular reactive oxygen species (ROS) and glutathione (GSH) levels. Moreover, we examined mitochondrial content, membrane potential, and ROS. Results: Cleavage and blastocyst formation rates began to decrease significantly in the 40 µM Cd group compared with the control. During post-blastulation, development was significantly delayed in the Cd group. Cd exposure significantly decreased cell number and increased apoptosis rate compared with the control. Embryos exposed to Cd had significantly higher ROS and lower GSH levels, as well as lower expression of antioxidant enzymes, compared with the control. Moreover, embryos exposed to Cd exhibited a significant decrease in mitochondrial content, mitochondrial membrane potential, and expression of mitochondrial genes and an increase in mitochondrial ROS compared to the control. Conclusions: We demonstrated that Cd exposure impairs porcine embryonic development by inducing oxidative stress and mitochondrial dysfunction. Our findings provide insights into the toxicity of Cd exposure on mammalian embryonic development and highlight the importance of preventing Cd pollution.

• 대한전기학회논문지
• /
• 제39권2호
• /
• pp.183-191
• /
• 1990

Polycrystalline CdS film have been prepared by coating a slurry constiting of CdS, CdCl2, various amount of InCl3 and propylene glycol on glass substrate and by sintering in a nitrogen atmosphere, and their sintering behaviors, electrical properties and optical properties have been investigated. As the amount of InCl3 increases, the enhancing effect of CdCl2 on sistering decreses resulting in a sharp decrease in optical transmittance and an increase in electrical resistivity. The carrier concentration is almost independent of InCl3 added due to the occurrence of chlorine doping and to the compensating effect of indium dopant. Microstructure an optical properties of CdS film, which contain CdCl2 and InCl3 before sintering, can be improved by sintering in a sealed boat.

• 대한화학회지
• /
• 제39권4호
• /
• pp.312-317
• /
• 1995