• Nuclear Engineering and Technology
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• v.53 no.6
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• pp.1924-1930
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• 2021

By using miniature SENB specimens, the fracture properties of the materials in the region of welded metal, 321 stainless steel heat affected zone, 690 alloy heat affected zone of 321/690 dissimilar metal girth welded joints were tested. Both the J-resistance curves and critical fracture toughness of the three different materials are affected by the crack size because of the effect of crack tip constraint. Groups of constraint corrected J-resistance curves of the three materials are obtained according to J-Q-M approach. The welded metals exhibit the best fracture resistance but the worst fracture resistance is observed in the material of 690 alloy heat affected zone.

• Nuclear Engineering and Technology
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• v.55 no.10
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• pp.3549-3558
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• 2023

The jet pump can be used in a test device of a nuclear reactor for high flow amplification as it reduces inlet flow requirement and thereby size of the process components. In the present work, a miniature jet pump was designed to meet high flow amplification greater than 3. Subsequently, experiments were carried out using a test setup for design validation and performance evaluation of the jet pump for different parameters. It was observed that a minimum pressure of 0.6 bar (g) was required for the secondary fluid inside the jet pump to ensure cavitation free performance at high amplification. Spacing between the nozzle tip and the mixing chamber entry point had significant effect on the performance of the jet pump. Variation in primary flow, temperature and area ratio also affected the performance. It was observed that at high flow amplification, the analytical solution differed significantly from experimental results due to very large velocities encountered in the miniature size jet pump.

• 한국전산유체공학회:학술대회논문집
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• 2008.08a
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• pp.42.5-42.5
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• 2008

• Journal of Life Science
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• v.20 no.4
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• pp.467-473
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• 2010

Gangliosides are a major component of the plasma membrane of mammalian cells, which are directly involved in a variety of immunological events, including cell-to cell or cell-to-protein interactions. In this study, we investigated whether gangliosides, sialic acid-containing glycosphingolipids, are related to rejection during the xenotransplantation of NIH-miniature pig livers and hearts to humans. Both high performance thin-layer chromatography and immunohistochemistry analyses revealed that the expression of gangliosides in the liver tissue of NIH-miniature pigs was higher than that in the heart. Gangliosides GD3, GD1a, GD1b, GT1b and GQ1b were observed in both the liver and heart, whereas GQ1b was detected only in the liver, indicating that the ganglioside expression profiles are tissue specific. Moreover, other ganglio-series gangliosides, including GM3, were not detected in the livers and hearts of NIH-miniature pigs. Taken together, these results suggest that gangliosides may play important roles in immune responses in clinical xenotransplants of pig livers and hearts.

• Journal of Embryo Transfer
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• v.27 no.2
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• pp.107-111
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• 2012

Miniature pig sperm cryopreservation is continually researched in biotechnology for breed conservation and reproduction. It is important to control the temperature at each stage of cryopreservation and cryoprotectant. It is also necessary to find the optimal cryoprotectant concentration and chemical elements of the extender. Recently, many studies have used various cryoprotectant materials, such as dimethyl sulphoxide (DMSO), ethylene glycol (EG), antifreeze protein (AFP), amides, and glycerol. Glycerol is a commonly used cryoprotectant. However, glycerol has critical cytotoxic properties, including osmotic pressure and it can cause irreversible damage to live cells. Therefore, We focused on membrane fluidity modifications can reduce cell damage from freezing and thawing procedures and evaluated on the positive effects of trehalose to the viability, chromatin integrity, and motility of boar sperm. Miniature pig sperm was separated from semen by washing with modified- Modena B (mMB) extender. After centrifugation, the pellet was diluted with the prepared first extender. This experiment was designed to compare the effects that sperm cryopreservation using two different extenders has on sperm chromatin. The control group used the glycerol only and it was compared with the glycerol and glycerol plus trehalose extender. Sperm viability and motility were evaluated using WST1 assays and computer-assisted semen assays (CASA). Chromatin structure was examined using acridine orange staining. For the motility descriptors, trehalose caused a significant (p<0.01) increase in total motility ($57.80{\pm}4.60%$ in glycerol vs. $75.50{\pm}6.14%$ in glycerol + trehalose) and progressive ($51.20{\pm}5.45%$ in glycerol vs. $70.74{\pm}8.06%$ in glycerol + trehalose). A significant (p<0.05) increase in VAP ($42.70{\pm}5.73{\mu}m/s$ vs. $59.65{\pm}9.47{\mu}m/s$), VSL ($23.06{\pm}3.27{\mu}m/s$ vs. $34.60{\pm}6.58{\mu}m/s$), VCL ($75.36{\pm}11.36{\mu}m/s$ vs. $99.55{\pm}12.91{\mu}m/s$), STR ($54.4{\pm}2.19%$ vs. $58.0{\pm}1.63%$), and LIN ($32.2{\pm}2.05%$ vs. $36.0{\pm}2.45%$) were also detected, respectively. The sperm DNA fragmentation index was 48.8% to glycerol only and 30.6% to glycerol plus trehalose. Trehalose added group showed higher percentages of sperm motility, stability of chromatin structure than glycerol only. In this study, we suggest that trehalose is effective in reducing freezing damage to miniature pig sperm and can reduce chromatin damage during cryopreservation.

• Journal of Animal Science and Technology
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• v.54 no.6
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• pp.395-400
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• 2012

This study was conducted to estimate the growth curve parameters for the body weight (BW) and body length (BL) of miniature pigs in Korea. Growth curve parameters were estimated through a nonlinear regression model using Gompertz, Logistic, and von Bertalanffy methods. A total of 25 piglets were measured monthly from birth up to 15 months of age to estimate both body weight and length. Results showed that the estimated average values for the body weight (body length) were 31.83 kg (58.77 cm) for the mature weight (A), 3.06 (1.74) for the growth ratio (${\beta}$), and 0.28 (0.52) for the maturing rate (${\kappa}$). Average inflection points showing maximum growth rate estimated each month for body weight were 3.97 kg and 11.70 cm, while for the body length were 1.06 kg and 21.61 cm. Moreover, the estimated maturation rates of the body weight and length for the group of Sire 1 were 0.22 and 0.40 respectively, whereas for the group of Sire 2 these values were 0.34 and 0.39. On the other hand, for the groups of Dam 1, Dam 2, and Dam 3, maturation rates for their body weights were 0.26, 0.28 and 0.33 respectively, while for their body lengths these values were 0.43, 0.37, and 0.38, respectively. The study also indicated a negative relationship between the values of mature weight and maturity rate for the body weight will result to a higher inflection point which is in contrast for the body length where results show that a positive relationship between the values of mature length and the maturity rate will result to a higher inflection point. Furthermore, the growth performance of miniature pig varies across stages but using these estimated growth curve parameters could improve the genetic traits of miniature pig.

• Journal of Veterinary Clinics
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• v.25 no.2
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• pp.79-84
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• 2008

For estimating the ovulation time in Miniature Schnauzer dogs during the estrous cycle, radioimmunoassay of plasma estradiol-$17{\beta}$ and progesterone concentrations was conducted on blood samples in 21 pregnant and 13 non pregnant dogs. When Day 0 was that plasma progesterone concentrations exceeded 4.0 ng/ml, on Day 64, parturition day, progesterone declined below 1.0 ng/ml with $0.92\;{\pm}\;0.29\;ng/ml$ and when Day 0 was that plasma progesterone concentrations declined below 1.0 ng/ml, on Day -64, progesterone increased above 4.0 ng/ml with $4.56\;{\pm}\;0.87\;ng/ml$. Gestational length was $63.71\;{\pm}\;1.35$ (Mean${\pm}$S.D.) days from plasma progesterone concentrations exceeded 4.0 ng/ml and was $66.29\;{\pm}\;1.98$ days from first male acceptance. The plasma estradiol-$17{\beta}$ concentrations reached maximum value with $28.20\;{\pm}\;2.86\;pg/ml$ on Day .2, and plasma progesterone concentrations reached $5.90\;{\pm}\;0.36 ng/ml, 5.18\;{\pm}\;0.32 ng/ml on Day 0, and the maximum of 61.58\;{\pm}\;10.47 ng/ml on Day 19 and 56.05\;{\pm}\;8.86\;ng/ml$ on Day 16 in pregnant and non pregnant dogs, respectively. Afterward, plasma progesterone concentrations declined below 1.0 ng/ml on Day 64 with $0.92\;{\pm}\;0.29\;ng/ml$ in pregnant cycles and on Day 58 with $0.95\;{\pm}\;0.63\;ng/ml$ in non pregnant dogs. No difference were found pregnant and non pregnant dogs in plasma estradiol-$17{\beta}$ and progesterone concentrations (p<0.01). Based on first male acceptance (Day 0), the maximum of plasma estradiol-$17{\beta}$ concentrations ($29.31\;{\pm}\;3.61\;pg/ml$) occurred on Day -1 and plasma progesterone concentrations exceeded 4.0 ng/ml on Day 2 in pregnant ($5.37\;{\pm}\;0.76\;ng/ml$) and non pregnant ($4.25\;{\pm}\;0.80\;ng/ml$) dogs. These results suggest that in Miniature Schnauzers, the ovulation occurred when plasma progesterone concentrations exceeded 4.0 ng/ml, 3 days after plasma estradiol-$17{\beta}$ peak and 2 days after first male acceptance.

• Journal of Veterinary Clinics
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• v.26 no.5
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• pp.445-449
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• 2009

For human organ transplantations, histidine-tryptophan-ketoglutarate solution (HTKS) and University of Wisconsin solution (UWS) have been shown to engender similar outcomes as gold standard cold preservation solutions ($4^{\circ}C$). To select the effective preservation solution for cold storage of kidney xenografts in miniature pig, which could be a potential source animal of bio-organs, this study compared early histopathological outcomes of cold preservation injury using HTKS and UWS. Twelve miniature pigs weighing 25.6 to 34.7 kg were divided into two groups (n = 6 per group), UWS group and HTKS group. The kidneys in each group were harvested, cold flushed, and preserved for 0, 24, 48, and 72 hrs at $4^{\circ}C$ with UWS or HTKS, respectively. Histolopathological examinations were assessed on kidney biopsy specimens, taken after each cold storage. The degree of renal injury was scored using 5 different criteria (pyknotic nuclei, disruption of cytoplasm, detachment of epithelium, loss of microvilli, tubular necrosis and loss of glomerular tufts) of the cellular components of the tissue. The degree of kidney damage was increased with prolonged cold ischemia time. UWS and HTKS have at least similar efficacy in kidney preservation within 24 hrs cold preservation time. However, in HTKS group cold-induced injury started to be observed more than in UWS group after 48 hrs of cold storage. In conclusion, UWS and HTKS were equally effective for cold preservation of miniature pig kidney in early preservation times; however, UWS may be more effective at longer preservation times as compared to HTKS.

• Journal of Embryo Transfer
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• v.23 no.2
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• pp.101-108
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• 2008

This study investigated the developmental ability and gene expression of somatic cell nuclear transfer embryos using ear skin fibroblast cells derived from miniature pig. When miniature pig (m) and landrace pig (p) were used as donor cells, there were no differences in cleavage (79.2 vs. 78.2%) and blastocyst rates (27.4 vs. 29.7%). However, mNT blastocysts showed significantly higher apoptosis rate than that of pNT blastocysts (6.1 vs. 1.7%) (p<0.05). The number of nuclei in pNT blastosysts was significantly higher than that of mNT (35.8 vs. 29.3) (p<0.05). Blastocysts were analyzed using Realtime RT-PCR to determine the expression of Bax-${\alpha}$, Bcl-xl, H19, IGF2, IGF2r and Xist. Bax-${\alpha}$ was higher in mNT blastocyst than pNT blastocyst (p<0.05). There was no difference in Bcl-xl between two NT groups. Bax-${\alpha}$/Bcl-xl was, however, significantly higher in mNT blastocyst compared to pNT. The expression of imprinting genes were aberrant in blastocysts derived from NT compared to in vivo blastocysts. H19 and IGF2r were significantly lower in mNT blastocysts (p<0.05). The expression of IGF2 and Xist was similar in two NT groups. However, imprinting genes were expressed aberrantly in mNT compared to pNT blastocysts. The present results suggest that the NT between donor cells derived from miniature pig and recipient oocytes derived from crossbred pig might affect reprogramming of donor cell, resulting in high apoptosis and aberrant expression patterns of imprinting genes.

• Journal of Embryo Transfer
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• v.27 no.1
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• pp.1-7
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• 2012

Somatic cell nuclear transfer (SCNT) for miniature pig has been developed for xenotransplantation and many other biomedical experiments. However, the efficiency of SCNT is still very low due to many factors. To optimize the surrogate mother condition for improvement of cloned miniature pigs efficiency, we investigated the effect of the status of surrogate mother on pregnancy, farrowed rate in SCNT pigs. After SCNT with mesenchymal stem cells as donor cells, the SCNT embryos were surgically transferred into the oviduct of surrogated pigs. To compare the effects of status of surrogate pigs on pregnancy, surrogate pigs were prepared by artificial abortion at day 20~29 (Group 1), 30~39 (Group 2), and 40~45 (Group 3) of gestation. After SCNT embryos transfer in three different status of surrogate pigs, Group 2 (56.3%) and 3 (55.6%) had significantly ($p$ <0.05) higher the pregnancy rate than group 1 (0%) at day 30 of gestation. The status of ovulation in surrogate pig also was investigated. Post-ovulation status (54.8%) had higher proportion than pre-ovulation status (38.7%) and ovulation status (6.5%). We obtained 19 cloned miniature piglets from seven surrogate gilts and five piglets are living healthy but fourteen piglets died soon after birth or stillbirth. The weights of piglets greatly differ from 254 to 1,296 g. Microsatellite analysis showed that cloned piglets were genetically different from the surrogate mother and cloned piglets were genetically equal to the donor cell. In conclusion, the present result indicates that artificially abortion method can improve the efficiency of pregnancy after SCNT in pigs. This study will provide available method for the further study and application in the field of xenotransplantation.