• Korean Journal of Animal Reproduction
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• v.20 no.2
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• pp.143-153
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• 1996

To improve the efficiency of nuclear transplantation in the rabbit, this study were evaluated the influence of celly cycle of donor nuclei on the in vitro developmental potential in the nuclear transplant embryos. The embryos of 16-cell stage were collected from the mated does at 48h post-hCG injection and they were synchronized to G1 phase of 32-cell stage. Synchronization of the cell cylce of blastomeres were induced, first, using an microtubules polymerization inhibitor, 0.5$\mu\textrm{g}$/ml colcemid for 10h to arrest blastomeres in metaphase, and secondly, using a DNA synthesis inhibitor, 0.1$\mu\textrm{g}$/ml aphidicolin for 1.5 to 2h to cleave to 32-cell stage and arrest them in G1 phase. The separated G1 phase blastomeres of 32-cell stage were injectied into enucleated recipient cytoplasms by micromanipulation. After culture until 20h post-hCG injection, the nuclear transplant oocytes were electrofused and activated by electrical stimulation. The nuclear transplant embryos were co-cultured for 120h. In vitro cultured embryos were monitored every 24h to assess for development rate. After in vitro cultue for 120h, the nuclear transplant embryos developed to blastocyst stage were stained with Hoechst 33342 dye for counting the number of blastomeres under a fluorescence microscopy. The cleavage rate of blastomeres from 16-cell stage stage rabbit embryos treated with colcemid for 10h or aphidicolin for 6h following colcemid for 10h were not significantly different. The electrofusion rate was similar by high in S and G1 phase donor nuclei as 80.6 and 79.1%, respectively. However, the nuclear transplant embryos using G1 phase donor nuclei were developed to blastocyst at high rate(60.3%) than those using S phase donor nuclei(26.0%). Moreover, the mean blastocyst stage were increased significantly(P<0.05) with the G1 phase donor nuclei(176.6 cells and 1.50 cycles), as compared with the S phase donor nuclei(136.6 cells and 1.42 cycles). These results show that the blastomeres of G1 phase were more successful as donor nuclei in the nuclear transplant procedure, compared with S phase.

• Korean Journal of Animal Reproduction
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• v.22 no.2
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• pp.137-143
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• 1998

The effects of continuous GH(hGH) secretion on the female reproduction was studies in adults female transgenic rats expressing the hGH gene with a mouse whey acid protein (mWAP) promotor. Two line of transgenic female rats carrying the mWAP/hGH gene were established and used in the study. One was characterized by relatively high levels of serum hGH (high line), and the other had relatively low levels (low line). 1. High line female rats had recurring, Pseudopregancy-like estrous cycles accompanied by increased serum progesterone level for 2 weeks after ovulation, and they were fertile. 2. In the rats, luteinization occurred spontaneously without cervical stimulation, probably due to high levels of serum hGH, which has prolactin (PRL)-like activity in the rat. 3. Low line female rats had recurring, regular 4-days estrous PRL surge following cervical stimulation were not, detected and PRL secretion was not induced by a dopamine antagonist. 4. The ovarian tissue in this line had a much higher number of corpora lutea and grew much heavier than in normal littermates, suggesting impairment of PRL induced structural luteolized. Su, pp.ession of PRL secretion in the low line rats was, at least in part, due to a marked decrease in the number of lactotrophs in the pituitary. The present study shows that the serum hGH level plays a crucial role in regulating luteal function in female transgenic rats expressing the hGH gene.

• 한국신재생에너지학회:학술대회논문집
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• 2010.11a
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• pp.143-143
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• 2010

GTL(Gas-to-Liquids)공정 중 합성가스 제조공정(Reforming Process)인 ATR(Auto-Thermal Reforming), SCR(Steam Carbon Reforming), POx(Partial Oxidation)의 시뮬레이션 연구를 수행하였다. Reforming 공정에서 생산된 합성가스는 GTL 합성유 제조공정인 FT(Fischer-Thropsch) 반응기로 주입되며, 합성유 생산에 최적의 효율을 보이는 H2/CO 비(합성가스에 포함된 반응물비)는 2.0으로 알려져 있다. FT공정은 합성가스를 원료로 고온 및 고압 반응을 거쳐 GTL 공정의 최종 생산품인 FT합성유를 제조하는 공정이다. 본 연구에서는 FT공정 효율 극대화를 위해 reforming 공정에서 생성되는 합성가스 내 H2/CO의 비를 2로 수렴토록 모사조건을 설정하였으며, 상기 조건을 만족하는 reforming 공정들의 운전 온도 및 feed 조성을 분석하고 비교하고자 한다. 현재 GTL 플랜트관련 산업계에 적용 혹은 주 연구대상인 reforming 공정으로는 ATR, SCR, POx 공정이 있다. ATR 공정은 $850{\sim}1100^{\circ}C$에서 메탄, 스팀 및 산소를 원료로 활용하여 H2 및 CO를 생산하는 공정으로 발열/흡열 반응이 상존하여 에너지 비용이 낮지만 공정구조 상 열회수설비 및 ASU(Air Separation Unit)이 필요하기에 CAPEX(초기설비 설치비용)가 높은 편이다. SCR공정은 CH4, Steam 및 CO2를 연료로 하기에 이산화탄소가 일정부분 포함된 가스전에도 적용이 가능하나 공정 운전 중 지속적으로 외부에서 열을 공급해야 하기에 에너지 투입비용이 높은편이며, 탄소침적의 문제가 있어 대용량 플랜트에는 적합하지 않다. POx공정은 약 $1,500^{\circ}C$의 고온에서 CH4가 O2에 의해 부분 산화되는 방식으로 촉매가 필요없어 설비비가 타 공정에 비해 저렴하나 생산가스의 H2/CO비가 다소 낮아 전체적인 GTL 공정효율이 저하되는 단점이 있다. 상기 세 공정은 GTL 산업계에서 실증 및 효율증대를 위해 주로 연구되는 공정이기에 본 연구의 분석대상으로 설정하였다. 본 연구에서는 상용공정모사기인 Aspen Plus를 활용하여 reforming 공정별로 FT합성공정의 최적 조건(H2/CO=2)을 만족하는 합성가스 생산조건 분석 및 비교를 수행할 예정이다. 운전조건인 공정 운전온도 및 feed 가스조성 등을 모사하기 위해 합성가스 reforming 공정을 모델링하고 공급유량 및 압력 등의 운전변수는 GTL국책과제 1단계 연구수행 결과를 토대로 선정하고자 한다. GTL공정의 경우, 설비의 운전조건이나 연료가스의 구성 및 유량에 따라 적합한 reforming 공정이 다르기에 본 시뮬레이션 결과를 향후 GTL 플랜트 공정모델 설계시 reforming 공정선정에 참고자료로 활용하고자 한다.

• Journal of Mushroom
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• v.18 no.3
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• pp.208-213
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• 2020

Burkholderia contaminans PSB-A and Burkholderia ambifaria PSB-B were isolated from button mushroom bed to estimate their phosphate solubility. The phosphate-solubilizing abilities of these strains were assessed by measuring the phosphorus content in a single and co-inoculation medium for 7 days. The co-inoculation of these two strains released the highest content of soluble phosphorus (166.3 ㎍ mL^-1) into the medium, followed by single inoculation of B. contaminans PSB-A (143.73 ㎍ mL^-1) and B. ambifaria PSB-B (127.1 ㎍ mL^-1). The highest pH reduction, organic acid production, and glucose consumption were also observed in the co-inoculation medium. According to the plant growth promotion bioassay, co-inoculation enhanced the growth of romaine lettuce much more than the single inoculation (20.4% for leaf widths and 16.6% for root lengths). Although no significant difference was noted between single and co-inoculation of bacterial strains in terms of phosphorous release and plant growth, co-inoculation of PSB may have a beneficial effect on crop growth due to a synergistic effect between the strains.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.2
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• pp.143-148
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• 2011

In this work, a composite formed by adding loess with lanthanium ("La-Loess") was proposed for effective removal of phosphate found in confined water bodies such as lake and reservoir. It was found that the theoretical maximum amount of lanthanum that can be attached to Loess was 2.68 mg La/g Loess. The phosphate removal was enhanced as an added amount of La-Loess composite increased. Furthermore, there was a noticeable difference in phosphate removal between Loess and La-Loess as the latter required 1.5 to 10 times less Loess than the former. Both Isotherm equations of Freundlich and Langmuir can be used to explain the phosphate adsorption characteristics in using La-Loess composites. The phosphate removal was very effective in the pH range of 5~8, which means that the proposed adsorbent can be directly applied to natural water without adjusting pH. Also, the La-Loess composites were well settled within 30 min without causing turbidity in water. Consequently, the proposed La-Loess can be strongly recommended for phosphate removal in confined water bodies.

• Fisheries and Aquatic Sciences
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• v.6 no.2
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• pp.59-65
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• 2003

The critical thermal maximum (CTM) of black rockfish, Sebastes schlegeli, was evaluated. Black rockfish were acclimated at $24^{\circ}C$, and then exposed to temperatures from 24 to $33^{\circ}C$. Black rockfish were kept in constant darkness and subjected to a gradual temperature increase $(1 ^{\circ}C\;12^{-1})$. The oxygen consumption rate (OCR) was measured using an automatic intermittent­flow-respirometer (AIFR) during the exposure period (from 119.3 to 143.5 h). The OCR increased from 94.5 to 214.2mL $O_2 kg^{-1}\;ww\;h^{-1}$ as the temperature rose from 24 to $29.4-30.9^{\circ}C$. Subsequently, the OCR increased abruptly, reaching 245.8-412.7mL $O_2 kg^{-1}\;ww\;h^{-1}$ at $32^{\circ}C$. This study suggests that the CTM for black rockfish is $29.4-30.9^{\circ}C$ when temperature is increased at $1^{\circ}C\;12h^{-1}$ following acclimation at $24^{\circ}C$.

• Journal of Pharmaceutical Investigation
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• v.25 no.2
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• pp.137-143
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• 1995

The peptide transporter can be utilized for improving the bioavailability of compounds that are poorly absorbed. Characterization of the dipeptide uptake into the human intestinal epithelial cells, HT-29 was investigated. The uptake of tritiated glycylsarcosine $([^3H]-Gly-Sar,\;0.1\;{\mu}Ci/ml)$ was measured in confluent or subconfluent HT-29, Caco-2, and Cos-7 cells. Uptake medium was the Dulbecco's Modified Eagle's Media (DMEM) adjusted to pH 6.0. Both HT-29 and Caco-2 cells expressed the dipeptide transporter significantly (p<0.005) but Cos-7 did not. Certain portions of passive uptake were observed in all three cell lines. Uptake of Gly-Sar was largest at 7 days after plating HT-29 cells with significant inhibition with 25 mM cold Gly-Sar (p<0.05). but expression ratio of the dipeptide transporter was 0.7, suggesting lower expression. The effect of pH on Gly-Sar uptake was not significant in the range of pH 6 to 8. Gly-Sar uptake was also inhibited with 50 mM carnosine, 25 mM Gly-Sar, and 35 mM cephalexin significantly (p<0.05). From above results the dipeptide transporter was expressed well in HT-29 cells and was similar to that in the small intestine, suggesting that large amounts of mRNA of the transporter from the cells can be obtained.

• Proceedings of the Korean Environmental Health Society Conference
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• 2003.06a
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• pp.140-143
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• 2003

This research was to determine and compare the inactivation of total coliform as the indicator organism with chlorine, chlorine dioxide and ozone for drinking water treatment. The inactivation of total coliform was experimentally analyzed for the dose of disinfectant, contact time, pH, Temperature and DOC. The experiments for the characterization of inactivation were performed in a series of batch processes with the total coliform as a general indicator organism based on chlorine, chlorine dioxide and ozone as disinfectants. The nearly 2.4, 3.0, 3.9 log inactivation of total coliform killed by injecting 1mg/L at 5 minutes for chlorine, chlorine dioxide and ozone. For the inactivation of 99.9%, Disinfectants required were 1.70, 1.00 and 0.60 mg/L for chlorine, chlorine dioxide and ozone, respectively. The bactericidal effects of disinfectants were decreased as the pH increased in the range of pH 6-9. The influence of pH change on the killing effect of chlorine dioxide was not strong, but that on ozone and free chlorine was sensitive. The bactericidal effects of the disinfectants were increased as the temperature increase. The activation energies were 36,053, 29,822, 24,906 J/mol of chlorine, chlorine dioxide, ozone for coliforms. The inactivation effects were shown in the lowest order of chlorine, chlorine dioxide and ozone.

• Applied Biological Chemistry
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• v.21 no.3
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• pp.137-143
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• 1978

Xanthine oxidase from bovine thyroid glands was found to contain FAD, molybdenum and iron in a ratio 1:0. 36:1. 6. The molecular weight of the thyroid enzyme was similar to that of the milk enzyme when estimated by gel filtration and polyacrylamide gel electrophoresis. The optimum pH for the enzyme activity was 7.8. The pH of the isoelectric point was determined to be 6.2 by electrofocusing. Sodium dodecyl sulfatepolyacrylamide gel electrophoresis experiment indicated that the enzyme was dissociated into subunits and that the molecular weight for the smallest subunit was 65,000 daltons. Absorption spectra were dissimilar between milk and thyroid xanthine oxidase.

• Proceedings of the KIEE Conference
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• 1993.07a
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• pp.140-143
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• 1993

Station Blackout(SBO) event means the complete loss of alternating current(AC) electrical power to the essential & nonessential switchgear buses in a nuclear power plants. Since many safety systems in nuclear power plants depend upon alternative current power, the SBO event could be an important contributor to damage of reactor core. Therefore, the SBO events have been considered as a very important safety issues in a nuclear power plants. In this paper, as evaluating the design characteristics of offsite & emergency power systems, an acceptable minimum SBO duration is calculated. And it is presented that the design method for alternative AC(AAC) sources to cope with the SBO events.