• 한국동물학회지
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• 제26권1호
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• pp.29-40
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• 1983

노랑초파리 (Drosophila melanogaster)의 야생형과 날개 돌연변이체인 흔적날개(vg)에 있어서 날개 성체원기의 미세구조의 차이를 비교검토하여 흔적날개의 표현형이 발현되는 원인의 일단을 규명코저 본 연구를 실시하였다. 야생형과 흔적날개 개체의 제 3 령기 말기의 유충으로 부터 10시간 간격은 채취한 날개 성체원기에서 나타나는 미세구조의 변화를 비교 관찰하여 얻은 결과는 다음과 같다. 1. 야생형의 경우 지방소적들은 응집한 후 당류로 변화되었지만 흔적날개의 경우는 응집현상과 당류로 변화되는 과정이 관찰되지 않았다. 2. 식세포작용에 의한 세포의 퇴화현상은 흔적날개 변이체와 야생형에서도 관찰되었다. 그러나 야생형에서의 식세포작용은 매우 약하였다. 3. 기관세지의 내벽이 톱니모양의 구조를 나타내고 있는 것은 모두 비슷하였으나 기관세지의 직경은 야생형의 경우 시간이 경과함에 따라 넓어지는 경향을 보였으며, 흔적날개의 경우는 반대로 좁아지는 경향을 나타내었다. 이와같이 흔적날개 돌연변이체도 유충발생 초기까지는 모두 정상적으로 이루어지지만 제 3 령기 유충시기에 이르러서는 지방산이 당류로 변화되는 gluconeogenesis과정에서 결함이 보이고 식세포작용에 의한 세포의 퇴화현상이 현저했으며, 기관세지의 발달은 미흡한 점으로 보아 이와같은 현상들이 흔적날개 형성과 깊은 관계가 있는 것으로 사료된다.

• Animal Bioscience
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• 제36권12호
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• pp.1889-1897
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• 2023

Objective: 'Cultured meat' has been suggested as means of solving the problems associated with overpopulation and gas emissions. Satellite cells are a major component in the production of cultured meat; however, these cells cannot be maintained in vitro over long periods. Fibronectin is a glycoprotein that affects biological processes such as cell adhesion, differentiation, and migration. Unfortunately, the characteristics of porcine satellite cells grown in a long-term culture when exposed to fibronectin-coated dishes are unknown. The objective of this study was to investigate the appropriate concentration of fibronectin coated dishes for proliferation and maintenance of porcine satellite cells at long-term culture. Methods: In this study, we isolated the satellite cells and fibroblast cells with pre-plating method. We next analyzed the cell doubling time, cell cycle, and rate of expressed paired box 7 (Pax7) and myogenic differentiation 1 (MyoD1) in porcine satellite cells cultured with 20 ㎍/mL of fibronectin-, gelatin-, and non-coated dishes at early and late passage. We then analyzed the proliferation of porcine satellite cells with various concentrations of mixed gelatin/fibronectin. We next determined the optimal concentration of fibronectin that would encourage proliferation and maintenance of porcine satellite cells in a long-term culture. Results: Doubling time was lowest when 20 ㎍/mL of fibronectin was used (as tested during an early and late passage). Levels of expressed Pax7 and MyoD1, assessed using immunocytochemistry, were highest in cells grown using fibronectin-coated dishes. The proliferation of gelatin/fibronectin mixed coatings had no significant effect on porcine satellite cells. The concentration of 5 ㎍/mL fibronectin coated dishes showed the lowest doubling time and maintained expression of Pax7. Conclusion: Fibronectin with 5㎍/mL effectively maintains porcine satellite cells, a discovery that will be of interest to those developing the next generation of artificial meats.

• Journal of Oral Medicine and Pain
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• 제21권2호
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• pp.225-242
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• 1996

The author studied to determine the sex and age of 8 ancient human skeletal remains, which had excavated from ancient tombs located in Yeanri, Kimhae. Some kinds of personal identification methods their skulls and teeth were used for this study and the results were obtained as follows : 1. Sex determination was possible in ancient teeth from 4th to 5th century, using detection of X-Y homologous amelogenin gene by polymerase chain reaction. 2. DNA analysis proved that the materials examined were all male, but which always did not coincide with the results from other methods for sex determination including comparison of sexual differentiation of cranium and teeth and use of discriminant functions in the dental measurement. 3. There was little difference of the estimated ages between the methods by regression of pulp cavity and attrition in teeth. The ages from these two methods always did not coincide with ones from evaluation closure of cranial and palatal sutures. 4. Sex and age of the materials were determined as follows ; $\cdot$ Y9 was estimated to be male in early sixties. $\cdot$ Yl2 was estimated to be male in late twenties to early thirties. $\cdot$ Y37 was estimated to be male in early forties. $\cdot$ Y70 was estimated to be male in early sixties. $\cdot$ Y87 was estimated to be male in late forties. $\cdot$ Y109 was estimated to be male in early forties. $\cdot$ Yl29 was estimated to be male in late thirties to early forties. $\cdot$ Yl42 was estimated to be male in late fifties to early sixties.

• 유통과학연구
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• 제15권6호
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• pp.47-56
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• 2017

Purpose - The purpose of this study is to examine the viability of imitation strategy. Imitation strategy is one of the strategic options that a late mover can choose, and by selecting the strategy, the company imitates key elements of the business model of first movers, and modifies them to suit its conditions. The author attempted to explain how the elements of first mover's business models were creatively adapted to suit the conditions of late movers so that they can secure market position face-to-face market leaders. Research design, data, and methodology - For the purpose of the study, Korean coffee franchise industry was selected to compare the strategies of first and late movers and to discuss imitation strategy in detail. The author conducted in-depth case study of first mover and business model innovator Starbucks and Ediya Coffee, one of their imitators. The paper examines how Ediya has imitated and modified the business model of Starbucks to secure its unique competitive position in domestic market by using value chain and generic strategy analysis. Results - Starbucks and Ediya were compared in terms of their interior design, the price level of beverages, the variety of side dishes, and shop locations. Starbucks have invested interior design heavily to shops, offered diverse beverages and side dishes with relatively high price, the shops are located in central areas, whereas Ediya has concentrated on achieving cost leadership in all value activities as maintaining the quality of key products. Ediya succeeded in achieving best-provider strategy, in which it enjoys both cost leadership and differentiation advantages, largely by the strategic alliance with the biggest coffee manufacturer, Dongsuh Foods in Korea. Conclusions - Though Ediya is the imitator of Starbucks, it has modified Starbucks business models and succeeded in providing the 'third place' experience for budget-minded customers. Ediya has also succeeded in benefiting its franchisees by lowering costs and simplifying the various tasks of coffee shop management. Due to these factors, Ediya could become one of the largest number shops as the coffee franchise in Korea.

• 한국철학논집
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• 제59호
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• pp.39-63
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• 2018

한말 기호학계는 호락논쟁이 학문 외적인 것으로 변질되고, '리무위', '심시기'를 기반으로 하는 전통적 입장과는 다른 다양한 학설들이 크게 호응을 얻게 되면서 학계의 급속한 분열 현상이 발생하게 된다. 하지만 한말 기호학계 성리학자들은 학계 내부의 갈등을 종식시키려는 동일한 지향점을 가지고 학계를 통합할 수 있는 일련의 노력들을 기울인다. 그럼에도 불구하고, 한말 기호학계는 다양한 학문적 입장 차이를 보였으며, 특히 자가설을 수립하여 이를 통해 새롭게 문인 집단화 하는 현상이 발생한다. 대표적으로 심주리의 성리설을 제시한 화서, 노사학파 그리고 리무위, 기유위, 성즉리, 심시기의 전통적 입장에 대해서는 동일하게 수용하면서도 미세한 입장 차이를 보였던 간재, 연재, 의당학파가 공존하고 있었다. 그리고 기호학계의 학문적 분화와 학파 분열의 과정을 통해 한말 기호학계를 비롯한 이 시기 성리학계를 특징짓는 심설논쟁이 광범위하게 펼쳐진다. 하지만 끝내 합의되지 않는 서로간의 논쟁 속에서도 이들 모두가 추구한 공통된 가치가 있으니 바로 성리학의 궁극적 목적인 도덕적 이상사회를 건설하는 것이었다. 결과론적으로 본다면 비록 그들이 추구했던 목적은 이루어지지 않았지만, 한말이라는 엄중한 시기에 이러한 요청이 더욱 절실하였음을 그들이 치열하게 펼쳤던 심설논쟁을 통해 확인할 수 있다.

• 자원환경지질
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• 제34권6호
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• pp.617-625
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• 2001

Skaergaard 암체는 광범한 in situ 화성분화작용을 격은 층상관입암의 대표적인 예로 널리 알려져 있다. 따라서 이 암체는 폐쇄계에서 미량원소변이를 modeling 할 수 있는 적지가 될 것이다. 그러나, 기존의 연구에 의하면 본 암체의 전암 및 광물의 회토류는 폐쇄계로서의 예상된 경향을 보이지 않는다(Haskin and Haskin, 1968; Paster et al., 1974). 발표된 분배계수, 공존광물들의 mode,그리고 전암 및 광물의 미량원소함량을 사용한 미량원소modeling에 의하면 Skaergaard 암체의 희토류는 분화후기에 일어난 광범한 인회석 결정작용에 크게 영향을 받았음을 보여준다. 미량원소modeling은 Upper Border Series에서 간헐적으로 나타나는 인회석이 기존에 주장되어 온 바와 같은 liquldus상이 아니라 진화하는 magma의 미량원소함량에는 영향을 끼칠 수 없는 interstitial phase임을 시사한다. 분화작용 말기에 Skaerganrd 마그마가 대류를 멈추거나 소규모로 대류를 할 때, 마그마 암장의 상부에 축적되는 휘발성분에 기인한 증가된 $PH_2$O가 인회석이 UBS에서 정출 되는 것을 방해하였을 것이다. 이와 같은 인회석의 특성을 고려해서 Skaergaard분화작용을 modeling하면 희토류는 폐쇄계로서의 예상된 경향을 따른다 이와 같은 결과는 최종 20% 분화작용기간 중에 양적으로 상당한 양의 마그마의 주입이나 분출을 수반하는 그 어떤 Skaergaard 암체의 분화model도 배격한다.

• 한국발생생물학회지:발생과생식
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• 제22권3호
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• pp.213-223
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• 2018

Ultrastructural studies on oocyte differentiation and vitellogenesis in the oocytes of female Kareius bicoloratus were investigated by transmission electron microscopy. The Golgi complex in the cytoplasm is involved in the formation of yolk vesicles that contain yolk carbohydrates in the yolk vesicle of oocytes in the early vitellogenic phase. In this phase, many pinocytotic vesicles (PVs), which are formed by pinocytosis, contain yolk precursors (exogenous substances). These substances are associated with exogenous heterosynthetic vitellogenesis. In yolked oocytes in the late vitellogenic phase, two morphologically different bodies, which formed by modified mitochondria, appear in oocytes. One is a multivesicular body (synthesized by autosynthetic vitellogenesis), and the other is a yolk precursor (an exogenous substance formed by heterosynthetic vitellogenesis). The multivesicular bodies (MVB) are taken into the yolk precursors (YP) and are transformed into primary yolk globules. However, after the YP mix with exogenous PVs near the zona pellucida, they are transformed into primary yolk globules. Vitellogenesis of this species occurs via endogenous autosynthesis and exogenous heterogenesis. Vitellogenesis occurs through endogenous autosynthesis, which involves the combined activity of the Golgi complex, mitochondria and MVB formed by modified mitochondria. However, heterosynthesis involves pinocytotic incorporation of extraovarian precursors (such as vitellogenin in the liver) into the zona pellucida (via granulosa cells and thecal cells) of the yolked oocyte.

• International Journal of Oral Biology
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• 제30권3호
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• pp.105-110
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• 2005

Periodontitis is a chronic infectious disease that leads to the destruction, one of the major cause of tooth loss in human. Osteoclast Differentiation Factor(ODF), also called as Receptor activator of NF-${\kappa}B$ ligand(RANKL), a surface-associated ligand on bone marrow stromal cells and osteoblasts, activates its cognate receptor RANK on osteoclast progenitor cells, which leads to differentiation of these mononucleated precursor cells. Osteoprotegerin(OPG), a decoy receptor, is released from stromal cells and osteoblasts to inhibit the interaction between RANKL and RANK. The experiment for the effect of pregnancy on gingival health showed greater gingival inflammation and edema during pregnancy, despite similar plaque index. There should be many factors affecting the periodontal health in pregnancy. In this experiment, we examined the direct effects of sex hormones(estrogen and progesterone) on the ODF/OPG expression in human gingival fibroblasts and periodontal ligament cells at the serum concentration of pregnancy. The ratio was high in the 1st trimester of pregnancy by estrogen and in the late 2nd trimester by progesterone. Therefore, the local periodontal destruction might be accelerated by these hormonal effect on the periodontal cells.

• Molecules and Cells
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• 제27권4호
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• pp.397-401
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• 2009

Olig2 transcription factor is widely expressed throughout the central nervous system; therefore, it is considered to have multiple functions in the developing, mature and injured brain. In this mini-review, we focus on Olig2 in the forebrain (telencephalon and diencephalon) and discuss the functional significance of Olig2 and the differentiation properties of Olig2-expressing progenitors in the development and injured states. Short- and long-term lineage analysis in the developing forebrain elucidated that not all late Olig2+ cells are direct cohorts of early cells and that Olig2 lineage cells differentiate into neurons or glial cells in a region- and stage-dependent manner. Olig2-deficient mice revealed large elimination of oligodendrocyte precursor cells and a decreased number of astrocyte progenitors in the dorsal cortex, whereas no reduction in the number of GABAergic neurons. In addition to Olig2 function in the developing cortex, Olig2 is also reported to be important for glial scar formation after injury. Thus, Olig2 can be essential for glial differentiation during development and after injury.

• 한국동물학회지
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• 제35권3호
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• pp.322-331
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• 1992

To investigate the svnthyesis of muscle proteins during differentiation of chicken myoblast, cvtosolic and membrane fractions were used for both sodium dodecvl sulfate polvcrylamide gel eBectrophoresis and two-dimensional gel electrophoresis. An extensive cell fusion was observed in 4 day culture. In the protein pattern of the cvtosolic fraction from SDS-PAGE. several protein bands including 250 kDa and 46 kDa showed remarkable changes during culture. the protein of 46 kDa was the most prominent one ann its optical density was the highest in 5 day culture (OD = 1.30). In the membrane fraction, band of 19.8 kDa showed the highest absorbance with 0.93 OD at 12 hr after initial plating and decreased gradually thereafter to 0.23 in 5 nay culture. From the results of two-dimensional gel electrophoresis of cytosolic fraction, the 46 kDa spot was observed as ko separated forms from culture 2 nary culture, and the sixte of this spot was the largest in 5 nay culture. In the pattern of membrane protein, the extensive appearance of newiv synthesized Proteins was found in a naut culture, but no Prominent spot was observed throughout culture. From the results of the present clay, we found that, during myoblast differentiation, the most prominent proteins were bands of 46 kDa and 19.8 kDa in cvtosolic and membrane fraction, respectively, and the appearance of new proteins was initiated at 48 hr after initial plating, and the 46 kDa protein was predominant in the cytoplasm of late culture in which extensive cell fusion was observed.