• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.351-354
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• 2001

In this experiment, we tested various nitrogen sources and then culture condition was optimized for industrial applications. The batch culture of Candida magnoliae SR101 grown in a defined medium supplemented with light steep water (LSW) as a sole nitrogen source showed a relatively high yield of erythritol production (53%), which was slightly higher than that using yeast extract as a nitrogen source, while the productivity and cell mass were maintained at similar levels. For the optimization of culture condition, the batch culture was performed. When the concentration of LSW was 65 mL/L in the defined medium containing 250 g/L of glucose, the concentration, yield and productivity of erythritol were 110 g/L, 44%, and 0.66 g/L-hr, respectively. The high yield and comparable productivity obtained with a cheap nitrogen source could be expected as a basis for the mass production of erythritol in the industrial scale.

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2003년도 학술발표대회 발표논문초록집
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• pp.71-71
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• 2003

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a multifunctional cytokine that has been implicated in the regulation of pre-implantation embryo development across several species. The aim of this study was to determine the effects of mouse granulocyte-macrophage colony-stimulating factor (mGM-CSF) on development of porcine parthenotes and nuclear transferred embryos, and on their expression of implantation-related genes. In the presence of bovine serum albumin, mGM-CSF did not increase the percentage of oocytes that developed to the blastocyst stage and at day 7 did not increase oocyte cell number. Addition of 10 mM GM-CSF to protein-free culture medium significantly increased the compaction and blastocoel formation of 1- to 2-cell parthenotes and cloned embryos developing in vitro. However, cell number was not increased when they were cultured in the presence of GM-CSF. Semi-quantitative reverse transcripts polymerase chain reaction (RT-PCR) revealed that mGM-CSF enhances mRNA expression of the leukemia inhibitory factor receptor, but does not influence interleukin-6 or sodium/glucose co-transporter protein gene expression in blastocyst stage parthenotes. These results suggest that mGM-CSF may enhance viability of porcine embryos developing in vitro in a defined culture medium.

• 수산경영론집
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• 제42권2호
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• pp.85-96
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• 2011

Oliver flounder population density affect Oliver flounder growth and mortality rate. In laboratory pilot experiment, Oliver flounder growth rate is inversely proportional to stocking density. But previous study has not proved external validity. This study is aimed to analyze the effect of stocking density on the Oliver flounder culture farms in Jeju Island. In order to do this, I selected 13 farms in Jeju island as a sample. In the study, various analytical methods including productivity analysis, regression analysis, statistical analysis were conducted for 13 Oliver flounder culture farms. The result of analysis can be summarized as follows. First, in case of the Oliver flounder culture farms, Bertalanffy equation is not applicable to the Oliver flounder growth. Second, the Oliver flounder stocking density, defined as the surface area of Oliver flounder per $m^2$ of water surface area, is preferred to density definition defined as the weight of Oliver flounder per $m^2$ of water surface area on the Oliver Flounder Culture Farms case. Third, growth rate and production weight on the Oliver flounder culture farms are inversely proportional to stocking density on spearman rank correlation test. When extensive comparable biological and culture condition data become available, analysis model can be easily modified to yield more accurate results.

• 한국수정란이식학회지
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• 제23권4호
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• pp.245-250
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• 2008

This study was designed to investigate the effect of essential amino acids (EAA) and/or non-essential amino acids (NEAA) on the development of parthenogenetic and somatic cell nuclear transfer (SCNT) porcine embryos in vitro. To evaluate the timing of amino acids supplementation, activated oocytes were cultured in NCSU23-PVA with EAA, NEAA or NEAA+EAA (AAs) during specific periods as below: EAA, NEAA or AAs were supplemented during Day 0 to 6 (whole culture period: ALL), Day 2 to Day 6 (post-maternal embryonic transition period: POST-MET), Day 5 to Day 6 (post-compaction period: POST-CMP), Day 0 to Day 2 (pre-maternal embryonic transition period: PRE-MET), or Day 0 to Day 4 (post-compaction period: PRE-CMP). Supplementation of NEAA decreased cleavage rates in PRE-MET and PRE-CMP and also decreased blastocyst rates in POST-CMP. On the other hand, EAA significantly enhanced blastocyst formation rate in POST-MET and no detrimental effect on embryonic development in other groups. Interestingly, NEAA and EAA had synergistic effect when they were supplemented to the medium during whole culture period. Supplementation of AAs also enhanced SCNT porcine embryo development whereas BSA-free medium without AAs could not supported blastocyst formation of SCNT embryos. In conclusion, existence of EAA and NEAA in defined culture medium variously influences the development of parthenogenetic and SCNT porcine embryos, and their positive effect are only occurred when both EAA and NEAA are supplemented to the medium during whole culture period. Additionally, AAs supplementation enhances the blastocyst formation of SCNT porcine embryos when they are cultured in the defined condition.

• 한국수정란이식학회지
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• 제24권2호
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• pp.105-108
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• 2009

This study was designed to investigate the effect of kinetin on in vitro development of parthenogenetic porcine oocytes exposed to demecolcine prior to activation. In vitro matured metaphase II stage oocytes were incubated in 0 or 2 ${\mu}$g/ml demecolcine supplemented defined culture medium for 3 h and the oocytes were activated electrically. The parthenogenetic porcine embryos were then cultured in 0 or 200 ${\mu}$M kinetin supplemented defined culture medium for 7 days. Regardless of demecolcine treatment, kinetin supplementation increased blastocyst rates significantly (7.0% versus 12.1% and 4.9% versus 8.5%; Control versus Kinetin and Demecolcine versus Kinetin + Demecolcine, respectively, p<0.05). Demecolcine treatment before activation tended to decrease blastocyst rates regardless of kinetin supplementation although it is not statistically significant. Total cell numbers in the blastocysts also tended to be elevated in embryos when supplemented with kinetin, however only the result between Kinetin and Demecolcine groups is statistically significant (37.6 ${\times}$ 7.2 versus 28.1 ${\times}$ 9.5, respectively, p<0.05). In conclusion, the present report shows that kinetin enhances developmental competence of parthenogenetic porcine embryo regardless of demecolcine pre-treatment before parthenogenetic activation when they were developed in defined culture condition.

• Clinical and Experimental Reproductive Medicine
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• 제38권4호
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• pp.216-221
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• 2011

Objective: To differentiate the human embryonic stem cells (hESCs) into the retinal pigment epithelium (RPE) in the defined culture condition and determine its therapeutic potential for the treatment of retinal degenerative diseases. Methods: The embryoid bodies were formed from hESCs and attached on the matrigel coated culture dishes. The neural structures consisting neural precursors were selected and expanded to form rosette structures. The mechanically isolated neural rosettes were differentiated into pigmented cells in the media comprised of N2 and B27. Expression profiles of markers related to RPE development were analyzed by reverse transcription-polymerase chain reaction and immunostaining. Dissociated putative RPE cells ($10^5$ cells/5 ${\mu}L$) were transplanted into the subretinal space of rat retinal degeneration model induced by intravenous sodium iodate injection. Animals were sacrificed at 1, 2, and 4 weeks after transplantation, and immnohistochemistry study was performed to verify the survival of the transplanted cells. Results: The putative RPE cells derived from hESC showed characteristics of the human RPE cells morphologically and expressed molecular markers and associated with RPE fate. Grafted RPE cells were found to survive in the subretinal space up to 4 weeks after transplantation, and the expression of RPE markers was confirmed with immunohistochemistry. Conclusion: Transplanted RPE cells derived from hESC in the defined culture condition successfully survived and migrated within subretinal space of rat retinal degeneration model. These results support the feasibility of the hESC derived RPE cells for cell-based therapies for retinal degenerative disease.

• Clinical and Experimental Reproductive Medicine
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• 제30권1호
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• pp.65-75
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• 2003

Objectives: To investigate the role of TGF (Transforming growth factor-$\beta$) involved in the paracrinic communication during decidualization between UEC (uterine epithelial cells) and USC (uterine stromal cells), we have employed a co-culture system composed of human endometrial epithelial and stromal cells in defined hormonal conditions. Design: In the co-culture, endometrial epithelial cells cultured in the matrigel-coated cell culture insert are seeded on top of the endometrial stromal cells cultured within a collagen gel. The co-culture was maintained for 48 hours under the following hormonal conditions: progesterone dominant condition (100 nM P4 and 1 nM E2) or estrogen-dominant condition (100 nM E2 and 1 nM P4). 10 ng/ ml HGF and/or 10 ng/ml TGF-$\beta$1 are added. Methods: RT-PCR is utilized to detect mRNAs quantitatively. Enzyme-linked immunosorbent assay (ELISA) and immunohistochemical staining are utilized to detect proteins in the tissue. Results: Prolactin mRNA is expressed in the co-cultured stromal cells under the progesterone dominant condition. TGF-$\beta$1 and its receptors are expressed in both the co-cultured epithelial and stromal cells irrespective of the steroid present, which is in contrast with no or negligible expression of TGF-$\beta$1 or its receptor in cells separately cultured. Both estrogen and progesterone significantly elevate the concentration of hepatocyte growth factor (HGF) in the conditioned medium of the co-culture with the value of 4, 325 pg/ml in E2-dominant and 2, 000 pg/ml in P4-dominant condition compare to 150 pg/ml in no hormone. In separately cultured stromal cells, administration of HGF induces the expression of TGF receptor 1 in both hormonal conditions, but induction of TGF receptor 2 is only manifest in the P4-dominant condition. Administration of TGF-$\beta$ and HGF directly induce the decidualization marker prolactin mRNA in separately cultured stromal cells. Conclusion: It is likely that steroid hormones induces prolactin mRNA indirectly by promoting the cell to cell communication between the stromal and the epithelial cells. TGF-$\beta$ and HGF are two possible paracrine mediators in the human endometrial decidualization.

• 한국수정란이식학회지
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• 제25권4호
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• pp.259-262
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• 2010

Optimization of the preimplantation mammalian embryo culture condition was widely focused on refining medium composition under the name of chemically defined media. However, recent research revealed that the alteration of physical environment can be a crucial factor to a successful embryo development. In this study, under the same embryo density, a novel culture device named oil-free micro tube culture (MTC) system was evaluated using porcine parthenogenetic embryos. The activated oocytes were placed into the 0.2 ml thin-wall flat cap PCR tube and cultured to the blastocyst stage. As a preliminary step, embryo density and culture medium volume were optimized under a standard drop culture system. The optimal embryo density range for in vitro culture was 0.5 embryos per ${\mu}l$ in $20\;{\mu}l$ drop (20.5%) and 1.0 embryos per ${\mu}l$ in $10\;{\mu}l$ drop (20.6%). Based on these results, we compared drop culture system and 'MTC' system in terms of the developmental rate to the blastocyst stage. In $20\;{\mu}l$ medium volume, the 'MTC' system showed similar blastocyst formation rate when compared with drop culture system (20.2% versus 20.5%, respectively) while the 'MTC' system showed lower blastocyst formation rate than drop culture system in $10\;{\mu}l$ one (12.7% versus 20.0%, respectively). Therefore the $20\;{\mu}l$ MTC system may be an alternative incubation system for short-distance embryo transport without carrying the $CO_2$ incubator and this provides novel embryo culture device to clinical veterinary embryologists.

• International Journal of Advanced Culture Technology
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• 제10권3호
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• pp.85-92
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• 2022

In previous private education expenses were concentrated only on expenses for elementary, middle, and high school students. Therefore, it is difficult to understand the actual condition of preschool children's private education expenses. To solve this problem, we analyze the 2013 and 2020 data of the Korea Welfare Panel to confirm the private education expenditures of pre-school children. Also, we examine the differences and changes in private education expenditures according to household variables. We selected the household variable as the socio-demographic variable of the study subject. We defined the household variable as the area and income of the household. We show the actual results of private education expenses for household variables using frequency analysis, descriptive statistical analysis, t-test, and one-way ANOVA of SPSS 27.

• 한국작물학회지
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• 제7권1호
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• pp.85-92
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• 1969

우리나라 수도작개량의 방향은 단위당 수량을 향상시키되 어디까지나 지역전체에 고도기술의 적용으로 고단수를 평준화시키면서 능률면에서도 공동작업관리로 이끌어 노동생산성을 높혀야 한다는데 있으므로 이를 구현하는 생산체제인 수도집단재배의 수행을 위한 이론을 연구하고 그 발전을 위한 기대효과와 전망을 구명하여야 하는바 현재까지의 결과를 요약하면 다음과 같다. 1. 수도작지대에서 고단수의 평준화를 위한 생산기술을 보급하고 고능율의 경영을 위해서는 집단재배가 가장 효과적인 방법의 하나이다. 2. 효과적인 집단재배를 실천하기 위하여는 단지의 수리, 토양, 품종 기타 영농상황을 보다 체계화하여야 한다. 3. 이와같은 기간재배기술은 경작농가의 협의에 의하여 재배력을 작성하고 단지내에서의 모든 재배법은 재배력에 의하여 통일되며 기간기술의 작업은 공동으로 하고 기타 세부작업은 개발로 한다. 4. 개별경영에서는 충실하게 도입되기 어려웠던 기술이 집단재배에서는 용이하게 도입될 수 있었으며 1968년도의 전국 집단재배 성적을 보면 일반재배에 비하여 평균 23.3%의 증수를 보이고 있다. 5. 현재 우리나라 집단재배의 형태는 초보적인 협정 영농형을 중심으로 추진되고 있는데 일부작업에는 공동작업형 및 청부작업형도 드물게 결합되고 있는 것이 보이고 있으나 앞으로 보다 안정다수확을 위한 성력화 또는 대규모의 기계화를 위해서는 공동작업형을 촉진시키면서 입지조건에 따라 기술신탁형이나 청부작업형을 결합시켜 나가는 방향으로 발전되어야 할것이다.