• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2002년도 춘계학술발표대회 발표논문초록집
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• pp.70-70
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• 2002

Sphingosine-1-phosphate(S1P) is one of the sphingolipid metabolites which affect a variety of cellular processes including the proliferation, differentiation, growth, survival, migration and gene expression. The present study was undertaken to investigate the effect of SIP on nuclear maturation of porcine oocytes. In vitro maturation frequency of porcine oocytes were compared in three different media; group Ⅰ: NCSU23＋0.1% PVA, group Ⅱ: NCSU23＋10% PFF(porcine follicular fluid), and group Ⅲ: NCSU23＋10% PFF＋10 ng/㎖ EGF＋2.5 mM β-mercaptoethanol. Each group containing 0.1 ㎎/㎖ cysteine was divided into 4 sub-groups of SIP concentration(0, 50, 500 and 5000nM). Porcine oocytes were incubated in each maturation medium supplemented with hormones(10 IU/㎖ PMSG and 10 IU/㎖ hCG) for 22h and then further cultured in the same medium without the hormones for 22h. After completion of in vitro maturation, the oocytes were fixed and stained to examine nuclear maturation by using a rapid stain method. In the group Ⅰ, the proportions of metaphase Ⅱ stage among oocytes cultured in 0nM(control), 50 nM, 500nM and 5000nM S1P were 45.5%, 66.7%, 56.6% and 48.7%, respectively. (omitted)

• Asian-Australasian Journal of Animal Sciences
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• 제22권7호
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• pp.962-968
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• 2009

The aim of this study was to compare the effects of oviductal fluid, porcine zygote medium (PZM)-3, PZM-4 and PZM-5, and modified PZM-5 culture media, and determine the effects of zona pellucida (ZP) removal on the development of nuclear transfer (NT) embryos. There were no significant differences in the rates of fusion and cleavage among the five different oviductal fluid concentrations. However, the rates of blastocyst formation and the cell numbers per blastocyst were high in the embryos at the 14 and 28 $\mu{g}$/ml concentrations of oviductal fluid compared to the 0, 56 and 100 $\mu{g}$/ml concentrations. The rates of cleavage and blastocyst formation, and the cell numbers per blastocyst were higher in the PZM-3, PZM-5 and modified PZM-5 media than in the PZM-4 medium. However, there were no significant differences in the fusion rates of oocytes among the four culture media. The cell numbers per blastocyst in the embryos without ZP were significantly greater than those with ZP. However, there were no significant differences in the rates of fusion, cleavage and blastocyst formation between the embryos with and without ZP. In conclusion, we improved blastocyst development and the quality of NT embryos by replacing PVA with 3 mg/ml of BSA in PZM-5 medium and supplementing the PZM-5 medium with 14 $\mu{g}$/ml oviductal fluid. The NT embryos produced by the zona-free NT method had a high rate of blastocyst formation in the modified PZM-5 medium.

• 방사선산업학회지
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• 제6권1호
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• pp.89-94
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• 2012

Three-dimensional network hydrogels were prepared by ${\gamma}$-irradiation of aqueous solutions of poly(vinyl alcohol) (PVA) and glycerol (Gly). Oven-drying was used to measure the gel fraction (G), hydration (H) or swelling behavior (S) of the prepared hydrogels. This study made a hypothesis that hydrogen bonds due to addition of glycerol and change of dry states such as freeze-drying (FD), room-drying (RD) and oven-drying (OD) acts on the G, H, and S. Interesting results on the hydrogen bonding effect in the prepared hydrogels are monitored at different drying conditions. The FD samples have a higher G values with increase in glycerol content as compared with the OD and RD samples. The formation of strong hydrogen bonding network among Gly molecules and hydrogel matrix was considered as the main driving force, resulting in the changes in the G, H, and S of the hydrogels under different drying conditions.

• 한국수정란이식학회:학술대회논문집
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• 한국수정란이식학회 2002년도 국제심포지엄
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• pp.74-74
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• 2002

Production of u 1-antitrypsin ($\alpha$AT) in transgenic cows has a great value in the field of medicine. The present study was conducted to determine the effect of chemically defined KSOM media on in vitro development of bovine transgenic nuclear transfer (NT) embryos. An expression plasmid for human $\alpha$AT was constructed by inserting a bovine beta-casein promoter, a green fluorescent protein (GFP) marker gene, and a human $\alpha$AT target gene into a pcDNA3 plasmid. Cumulus cells as donor nuclei in NT were collected from a Holstein cow and transfected by lipid-mediated method using FuGene6 (Roche Molecular Biochemicals, USA) as reagent. GFP expressed cumulus cells were introduced into recipient oocytes under DIC microscopy equipped with FITC filter set. After electrical fusion and chemical activation, reconstructed embryos were cultured in 1) SOF + 0.8% BSA, 2) KSOM + 0.8% BSA, 3) KSOM + 10% FBS and 4) KSOM +0.01% PVA for 192 h at 39$^{\circ}C$ with 5% $CO_2$, 5% $O_2$ and 90% $N_2$in humidified condition. The development of the embryos was recorded and the GFP expression in blastocyst was determined under FITC filter. The average fusion rate was 73.8% (251/340; n=8). The development rates to 2-4 cells, morula, blastocysts and expression rates in blastocysts varied from 70.3 to 76.5%, 30.2 to 33.8%, 25.4 to 33.8% and 11.8 to 15.6%, respectively. The difference in development and expression rates of embryos among 4 culture groups was not significant (P>0.05). This study indicates that chemically defined KSOM medium is also able to support development of bovine transgenic NT embryos at similar rate of SOF or KSOM supplemented with BSA or serum.

• Asian-Australasian Journal of Animal Sciences
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• 제21권2호
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• pp.181-189
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• 2008

The aim of this study was to evaluate the effects of $Ca^{2+}$, $HCO_3{^-}$ and BSA on the in vitro capacitation-associated protein tyrosine phosphorylation, hyperactivation and acrosome reaction in guinea pig sperm. Caudal epididymal sperm were incubated in four different groups: modified TALP (Tyrode's albumin lactate pyruvate) or TALP without one of the medium constituents ($Ca^{2+}$, $HCO_3{^-}$ and BSA). After incubation for the required time (0 h, 0.5 h, 1 h, 3 h, 5 h, and 7 h), sperm were removed for further experiment. The capacitation effect was assessed by CTC (Chlortetracycline) staining. Western blotting and indirect immunofluorescence were used to analyze the level and localization of tyrosine phosphorylation. The results showed that guinea pig sperm underwent a time-dependent increase in protein tyrosine phosphorylation during the in vitro capacitation and the percentage of protein tyrosine phosphorylated sperm increased from 36% to 92% from the beginning of incubation to 7 h incubation. Also, there was a shift in the site of phosphotyrosine-specific fluorescence from the head of sperm to both the head and the flagellum. Moreover, an absence of $Ca^{2+}$ or $HCO_3{^-}$ inhibited in vitro hyperactivation and acrosome reaction and decreased the phosphorylation of the proteins throughout the period of in vitro capacitation. However, an absence of BSA could not influence these processes if substituted by polyvinyl alcohol (PVA) in the medium.

• 공업화학
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• 제10권6호
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• pp.902-906
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• 1999

메틸셀루로스를 호스트고분자로 하고 copper(II) percolate를 산화제로 사용하여 기상상태에서 직접중합방법으로 전도성 복합필름을 합성하였다. 필름으로서 우수한 성형성과 기계강도를 갖고 있는 메틸셀루로즈는 PVA와 키토산과는 달리 피롤에 대하여 높은 친화성을 나타내어서 기상중합시 호스트고분자로 적합하였다. 기상중합법으로 합성된 폴리피롤은 복합재료 내에서 전도성네트워크를 형성하여 전도성 복합필름의 전기전도도는 $10^{-1}-10^{-7}S/cm$를 나타내었다. 피롤이 호스트고분자 내에서의 폴리피롤로 중합이 되는 정도를 UV-vis분광계로 확인하였다. 전도성 복합필름의 전기전도도와 기계강도는 산화제의 농도와 합성시간에 크게 의존하였다. TGA분석결과는 호스트고분자 내에 형성된 폴리피롤은 복합재료의 열적 안정성에 영향을 미치지 않는다. 전자현미경 분석결과 폴리피롤이 복합재료 내에 균일하게 침투하여 분산되어 있음을 나타내었다. DMA를 사용하여 폴리피롤과 호스트고분자와의 상용성을 조사하였으며 dynamic mechanical analysis(DMA) 분석결과 복합재료 내에서 폴리피롤의 함량이 증가되면서 상용성이 점진적으로 저하되었다.

• Journal of Microbiology and Biotechnology
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• 제23권4호
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• pp.473-482
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• 2013

The desulfurization ability of Sphingomonas subarctica T7b was evaluated using resting and immobilized cells with dibenzothiophene (DBT), alkyl DBTs, and commercial light gas oil (LGO) as the substrates. The resting cells of S. subarctica T7b degraded 239.2 mg of the initial 250 mg of DBT/l (1.36 mM) within 24 h at $27^{\circ}C$, while 127.5 mg of 2-hydroxybiphenyl (2-HBP)/l (0.75 mM) was formed, representing a 55% conversion of the DBT. The DBT desulfurization activity was significantly affected by the aqueous-to-oil phase ratio. In addition, the resting cells of S. subarctica T7b were able to desulfurize alkyl DBTs with long alkyl chains, although the desulfurization rate decreased with an increase in the total carbon number of the alkylated DBTs. LGO with a total sulfur content of 280 mg/l was desulfurized to 152 mg/l after 24 h of reaction. Cells immobilized by entrapment with polyvinyl alcohol (PVA) exhibited a high DBT desulfurization activity, including repeated use for more than 8 batch cycles without loss of biodesulfurization activity. The stability of the immobilized cells was better than that of the resting cells at different initial pHs, higher temperatures, and for DBT biodesulfurization in successive degradation cycles. The immobilized cells were also easily separated from the oil and water phases, giving this method great potential for oil biodesulfurization.

• 방사선산업학회지
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• 제7권1호
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• pp.87-91
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• 2013

Taraxacum platycarpum (TP) has been used for years without restriction on usual dose for its non-toxic nature and nonexistence of the side effects. To develop antimicrobial hydrogel, poly (vinylalcohol) (PVA) hydrogels containing the aqueous extracted TP as an antimicrobial agent were prepared by using gamma-rays irradiation. The antimicrobial activities of the TP hydrogels were tested against Staphylococcus aureus and Staphylococcus epidermidis by disc diffusion method. The inhibition zones (IZ) of the TP extracts and TP hydrogels against S. aureus were 16 mm and 20 mm and against S. epidermidis was 10 mm and 13 mm, respectively. In conclusion, the TP hydrogel that has an excellent antimicrobial activity was proved to be a valuable material for functional skin care.

• 한국전기전자재료학회논문지
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• 제32권4호
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• pp.333-340
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• 2019

The effects of compaction methods on the sintering density, microstructures, and mechanical properties were investigated in ${\alpha}-alumina$ ceramics. ${\alpha}-Alumina$ powders were granulated with a 10% aqueous solution of polyvinyl alcohol (PVA). Uniaxially pressed (UAP) and cold isostatic-pressed (CIP) samples were prepared by pressing uniaxially at a pressure of 1 ton for 1 min, and isostatically at 200 MPa for 15 min, respectively. Subsequently, both types of samples were sintered at $1,200^{\circ}C$, $1,300^{\circ}C$, $1,400^{\circ}C$, $1,450^{\circ}C$, $1,500^{\circ}C$, $1,550^{\circ}C$, and $1,600^{\circ}C$ at a rate of $5^{\circ}C/min$ for 2 h. The CIP samples were better than the UAP samples for all properties measured, such as the sintering density, Vicker's hardness, and toughness. The CIP sample sintered at $1,400^{\circ}C$ showed the maximum Vicker's hardness and toughness; this may be attributed to the competing effects of a decrease in porosity and the growth of grains with increasing sintering temperature.

• Clinical Endoscopy
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• 제56권5호
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• pp.604-612
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• 2023

Background/Aims: We developed a new endoscopic submucosal dissection (ESD) simulator and evaluated its efficacy and realism for use training endoscopists. Methods: An ESD simulator was constructed using polyvinyl alcohol hydrogel sheets and compared to a previous ESD simulator. Between March 1, 2020, and December 30, 2021, eight expert endoscopists from three different centers analyzed the procedure-related factors of the simulator. Five trainees performed gastric ESD exercises under the guidance of these experts. Results: Although the two ESD simulators provided overall favorable outcomes in terms of ESD-related factors, the new simulator had several benefits, including better marking of the target lesion's limits (p<0.001) and overall handling (p<0.001). Trainees tested the usefulness of the new ESD simulator. The complete resection rate improved after 3 ESD training sessions (9 procedures), and the perforation rate decreased after 4 sessions (12 procedures). Conclusions: We have developed a new ESD simulator that can help beginners achieve a high level of technical experience before performing real-time ESD procedures in patients.