• Journal of Embryo Transfer
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• v.14 no.3
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• pp.171-176
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• 1999

This study was carried out to investigate the effect of co-culture system(bovine oviduct epithelial cells; BOEC) and defined culture system (modified TALP ; mTALP) on the conception of embryos transferred, and pregnancy and twin birth rates after transfer of fresh or frozen-thawed bovine blastocysts produced in vitro were also evaluated. Oocytes from the slaughterhouse ovaries were matured and fertilized using general protocol. The results obtained were as the following. The pregnancy rate after transfer was higher in co-culture group than in mTALP group, but was not signficantly different, and there is no difference between fresh embryo group and frozen-thawed embryo group in conception rate. The conception rate was not different whether 3∼4 blastocysts or 2 blatocysts transferred into a recipient, but the production rate of twin calves was significantly higher (p<0.05) when 3∼4 embryos transferred. The average birth weight of twin calves(24.38kg) was numerically, but not significantly lighter than that of single calves(26.68kg).

• Journal of Microbiology and Biotechnology
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• v.18 no.7
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• pp.1252-1256
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• 2008

Cell recycled culture of succinic acid-producing Anaerobiospirillum succiniciproducens was anaerobically carried out using an internal membrane filter module in order to examine the physiological response of A. succiniciproducens to a high-cell-density environment. The optimal growth of A. succiniciproducens and its enhanced succinic acid productivity were observed under $CO_2$-rich conditions, established by adding $NaHCO_3$ and $Na_2CO_3$, in the cell recycled system. A. succiniciproducens grew up to 6.50 g-DCW/l, the highest cell concentration obtained so far, in cell recycled cultures. The cells did not change their morphology, which is known to be easily changed in unfavorable or stress environments. The maximum productivity of succinic acid was about 3.3 g/l/h, which is 3.3 times higher than those obtained in batch cultures. These results can serve as a guide for designing highly efficient cell recycled systems for succinic acid at a commercial level.

• The Korean Journal of Physiology and Pharmacology
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• v.14 no.3
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• pp.169-176
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• 2010

The hyperosmotic stimulus is regarded as a mechanical factor for bone remodeling. However, whether the hyperosmotic stimulus affects $1{\alpha}$, 25-dihydroxyvitamin $D_3$ ($1{\alpha},25(OH)_2D_3$)-induced osteoclastogenesis is not clear. In the present study, the effect of the hyperosmotic stimulus on $1{\alpha},25(OH)_2D_3$-induced osteoclastogenesis was investigated in an osteoblast-preosteoclast co-culture system. Serial doses of sucrose were applied as a mechanical force. These hyperosmotic stimuli significantly evoked a reduced number of $1{\alpha},25(OH)_2D_3$-induced tartrate-resistant acid phosphatase-positive multinucleated cells and $1{\alpha},25(OH)_2D_3$-induced bone-resorbing pit area in a co-culture system. In osteoblastic cells, receptor activator of nuclear factor ${\kappa}B$ ligand (RANKL) and Runx2 expressions were down-regulated in response to $1{\alpha},25(OH)_2D_3$. Knockdown of Runx2 inhibited $1{\alpha},25(OH)_2D_3$-induced RANKL expression in osteoblastic cells. Finally, the hyperosmotic stimulus induced the overexpression of TonEBP in osteoblastic cells. These results suggest that hyperosmolarity leads to the down-regulation of $1{\alpha},25(OH)_2D_3$-induced osteoclastogenesis, suppressing Runx2 and RANKL expression due to the TonEBP overexpression in osteoblastic cells.

• Journal of the Korean Society of Visualization
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• v.18 no.3
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• pp.84-89
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• 2020

Cancer cells secrete angiogenic factors, and nearby vasculatures make new blood vessels essential for cancer development and metastasis in response to these soluble factors. Many efforts have been made to elucidate cancer-endothelial cell interactions in vitro. However, not much is known due to the lack of a suitable co-culture platform. Here, we introduce a 3D printing-based microfluidic system that mimics the in vivo-like cancer-endothelial cell interactions. The tumoroids and endothelial cells are co-cultured, physically separated by porous fibrin gel, allowing communication between two cell types through soluble factors. Using this microfluidic system, we were able to visualize new vessel formation induced by tumoroids of different origins, including liver, breast, and ovary. We confirmed that the ovarian tumoroids most induced angiogenesis while the other two cancer types suppressed it. Utilization of the proposed co-culture platform will help the researchers unveil the underlying mechanisms of the dynamic interplay between tumor and angiogenesis.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.38 no.4
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• pp.311-319
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• 2012

Seborrheic dermatitis (SD) is the skin disease occurred because of Malassezia yeast which grows on the skin and scalp, and this yeast lives on sebum lipid, and their metabolite, free lipid acids are thought to be the main irritant on skin. To find out effective cosmeceutical ingredients to treat SD symptoms, we established novel cell-based in vitro model mimicking SD symptoms. This in vitro model adopted the co-culture system with primary sebocyte & HaCaT keratinocyte. We used M. globosa yeast extract, arachidonic acid, linoleic acid and dihydrotestosterone as SD inducers. In the co-culture system with optimized concentrations for SD-inducing cocktail, the production of IL-8 and sebum lipids increased up to 2-fold, and then we screened with commercial essential oils by monitoring IL-8 as a key inflammatory biomarker. Then we found that Cinnamomum zeylanicum oil, Mentha arvensis oil effectively down-regulated IL-$1{\alpha}$, IL-6, IL-8 cytokines which over-produced by SD-inducing cocktail. Additionally, two essential oils also showed inhibitory effect on sebum lipid synthesis from primary sebocyte and growth inhibitory effect to M. globosa yeast (MICs were lower than 0.0625 %). Our recent results suggest that Cinnamomum zeylanicum oil and Mentha arvensis oil could be effective natural herbal remedies to relieve or protect scalp seborrheic dermatitis.

• International Journal of Advanced Culture Technology
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• v.9 no.4
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• pp.424-430
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• 2021

The purpose of this study is to analyse the characteristics and spreading laws of parameters such as fire smoke, concentration of CO, visibility, and temperature at fire scene in high-rise residential buildings under the different conditions of fire doors and automatic fire extinguishing systems. Using Pyrosim to simulate diverse fire scenes in a high-rise apartment with corridors, to analyze the changes in those parameters. The results show that when a fire occurs, closing the fire-fighting corridor will increase the smoke temperature and concentration of CO in the stairwell, and reduce the height and visibility of the smoke layer; the automatic fire extinguishing system effectively suppresses the increase in the temperature of the fire smoke and the sedimentation of the smoke layer. Reasonable setting and operation of the automatic fire extinguishing system could effectively inhibit the spread of fire. Although closing fire corridor can slow down the direct upward spread of smoke through the corridor, it will force the fire smoke into the stairwell, which will seriously affect evacuation through the stairs. Therefore, in order to reduce risks, it is forbidden to close the fire doors of the firefighting corridor and stacking combustible materials in the corridor, Also, intensifying inspections and ensuring the normal operation of the automatic fire extinguishing system are indispensable. Based on the research results, the significance of installing fire-fighting facilities in the construction of high-rise apartments was discussed and proved.

• Proceedings of the PSK Conference
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• 2003.04a
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• pp.154.2-155
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• 2003

Recently, we developed a new anti-osteoporotic agent, DW-1350, which not only inhibited osteoclast formation but also induced osteoblast differentiation through the in vitro randomized screening studies. We identified inhibitory activities of DW-1350 for each step of osteoclast differentiation, fusion and pit formation process in co-culture system with mouse bone marrow and primary osteoblasts. (omitted)

• Environmental Analysis Health and Toxicology
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• v.6 no.1_2
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• pp.71-82
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• 1991

Rat embryos were cultured out of the mother from the head-fold stages, 9.5 days to 11.5 days during which they start to develop the brain, eyes, ears and cardiovascular system etc. We principally did the basic experiment in order to establish the best condition of the rat whole embryo culture in our laboratory. The temperature in the culture system was maintained 37$^{\circ}C$$\pm$0.2$^{\circ}C$ for 48 hrs. The culture was carried out in humidified atmosphere of the air, intially, the bottles were equilibrated with 5% $O_2$,5% $CO_2$, and 90% $N_2$gas mixture. After 22 or 24 and 29 or 30 hrs the cultures were reequilibrated with 20% $O_2$, 5% $CO_2$,75% $N_2$and 40% $O_2$, 5% $CO_2$, 55%$N_2$respectively. Various types of sera were tested and for the purpose of minimizing the quantity of rat serum, artificial medium was also tried and it was determined that rat serum supported normal growth over a period of 48 hrs, based on total growth analysis and structural comparisons with in vivo specimens.

• Environmental Mutagens and Carcinogens
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• v.22 no.3
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• pp.175-182
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• 2002

Endocrine disruptors (EDs) are the chemicals that affect endocrine systems through activation or inhibition of steroid hormone response. It is necessary to have a good system to evaluate rapidly and accurately endocrine-disrupting activities of suspected chemicals and their degradation products. The key targets of EDs are nuclear hormone receptors, which bind to steroid hormones and regulate their gene transcription. We constructed a co-expression system of Gal4p DNA binding domain (DBD)- ligand binding domain of human estrogen receptor $\alpha$ or $\beta$, and Gal4p transactivation domain (TAD)-co-activator AIB-1, SRC-1 or TIF-2 in Saccharomyces cerevisiae with a chromosome-integrated lacZ reporter gene under the control of CYC1 promoter and Gal4p binding site (GAL4 upstream activating sequence, GAL4$_{UAS}$). Expression of this reporter gene was dependent on the presence of estrogen or EDs in the culture medium. We found that the two-hybrid system with combination of the hER$\beta$ LBD and co-activator SRC-1 was most effective in the xenoestrogen-dependent induction of reporter activity. The extent of transcriptional activation by those chemicals correlated with their estrogenic activities measured by other assay systems, indicating that this assay system is efficient and reliable for measuring estrogenic activity. The data in this research demonstrated that the yeast detection system using steroid hormone receptor and co-activator is a useful tool for identifying chemicals that interact with steroid receptors.s.

• Proceedings of the Korean Society of Computer Information Conference
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• 2022.07a
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• pp.655-656
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• 2022

4차산업혁명 등의 스마트 산업 발전으로 농업분야에도 점점 전문화 및 분업화된 ICT기반 기술이 수용되고 있으며, 이에 기반한 삶의 질 향상은 계절과 무관하게 언제나 신선한 과일이나 채소를 제공받고 싶어하는 소비자들의 요구를 증대시키고 있다. 본 논문에서는 신선한 과일이나 채소를 사계절 구분없이 가정에 제공할 수 있도록 단기 육묘가 가능하고, 육묘종에 따라 생육환경을 맞춤형으로 관리하여 별도의 시설 및 인적 자원을 최소화할 수 있는 스마트 육묘재배 시스템을 제안한다.