• Proceedings of the Korea Society of Poultry Science Conference
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• 2001.11a
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• pp.74-76
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• 2001

Comparing to mammals, male bird has the homozygote ZZ and female has the heterozygote n. Therefore, the sex of fertilized eggs is defined by female chromosome constitution. Although this cytological observation had been established, the molecular and cellular mechanism of germ cell differentiation are essentially unknown in aves. Especially, the differentiation of germ cells in mixed-sex chimeras has not yet been clearly elucidated. Primordial germ cells, which are the progenitors of sperm or egg after sexual maturity, firstly arise in the epiblast and migrate to embryonic gonads through the blood vessel. During the embryo development, these PGCs differentiate in the pathway of mate or female, respectively and develop the sperm or egg cells after sexual maturity. In this paper, we confirmed that the female PGCs could migrate into the recipient male gonads after transferring and differentiate into germ cells in the embryonic stages. The primordial germ cells were isolated from the female embryonic gonads of 5.5-day-old incubation and re-injected into the male recipient embryos of 2-day-old incubation, which produced mixed-sex chimera in the germline. The finding in this study demonstrated the ability of migration and differentiation of gonadal primordial germ cells in mixed-sex chicken.

• Korean Journal of Agricultural and Forest Meteorology
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• v.9 no.1
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• pp.55-60
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• 2007

This study was conducted to find characteristics of photosynthesis for dwarf and street tree cultivars of Hibiscus syriacus L. Characteristics of growth and flowering on some cultivars were investigated. The photosynthetic capacity for the cultivars was also measured. Bulsae showed the best height increase; Soyang represented the lowest growth. Baektanshim ${\times}$ Kyungbuk1 had the largest number of branches and leaves. Sundeok and Bulsae were the best in terms of height and width of flower, Soyang showed the smallest flowers. According to the analysis of chlorophyll content (chlorophyll a, b, total) for the cultivars, there was little difference between Sundeok and Bulsae. Based on light response curves for cultivars, it was found that Baektanshim ${\times}$ Kyungbuk1 and Soyang had lower light compensation and light saturation points than Bulsae and Sundeok. Cultivars Baektanshim ${\times}$ Kyungbuk1 and Soyang were also low in dark respiration, photosynthetic capacity, and net apparent quantum yield. In conclusion, it is recommended that cultivars Baektanshim ${\times}$ Kyungbuk1 and Soyang might be used as a dwarf type due to photosynthetic capacity.

• Clinical and Experimental Reproductive Medicine
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• v.30 no.4
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• pp.293-298
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• 2003

목 적: 인간의 배아줄기세포는 전분화능과 영속성을 가지고 있어 발생 및 분화에 관련된 기초 연구 뿐 만 아니라 재생의학, 약물검색 등에서도 매우 유용한 재료로 이용될 수 있다.본 연구에서는 유전체의 변형이 배아줄기세포주의 확립 효율에 미치는 영향을 살펴보고자 비정상적인 포배기 배아에서 내세포괴를 분리하여 배양하였다. 연구 방법: 인간의 체외수정 및 배아이식술에서 공여 받은1개 또는3개의 전핵이 관찰되는 비정상 수정란 (n=20)과 착상전 유전진단에서 이수성이 확인된 배아 (n=27)를 대상으로 하였다. 일반적인 immunosurgery 방법으로 영양배엽세포들을 제거하고 내세포괴를 분리한 후 PMEF 혹은 STO feeder 세포위에서 배양하였다. 배아줄기세포의 배양시스템을 검증하기 위해서 이미 확립된 Miz-hES1 cell line을 동시에 같은 조건 하에서 계대배양하였다. 결 과: 비정상 수정란에서 발생된 포배기 배아에서 분리한 1개의 내세포괴가 배아줄기세포와 유사한 colony를 형성하였으나, 계대배양에는 실패하였다. 이수성 배아에서 발생된 포배기 배아의 내세포괴 배양에서는 두개의 colony가 계대배양 중에 영양배엽세포의 형태로 분화되어 미분화 상태를 유지하지 못하였다. 동일한 시기와 조건 하에서 계대배양된 Miz-hES1 cell line이 미분화상태로 유지됨을 karyotyping (46, XY)과 immunophenotyping (positive in SSEA-3 and -4)으로 확인하였다. 결 론: 본 연구의 결과에서 비정상 수정란과 이수성 배아에서 발생된 포배기 배아에서 유래한 내세포괴는 배아줄기세포주 확립 및 미분화 상태 유지 능력이 매우 저조한 것으로 여겨진다. 따라서, 인간의 배아줄기세포주를 확립하는데 있어 배아의 정상여부가 중요한 요소로 작용할 것으로 생각된다.

• Korean Journal of Heritage: History & Science
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• v.46 no.2
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• pp.166-185
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• 2013

After analyzing the location, arrangement, inner structure, and form of the hunting pit in the Bronze Age, this paper sets up three types and talks about types of hunting pits. After analyzing the types of the hunting pit, three types of hunting pits are derived: mountain district - large group's arrangement - long oval - I II type(A), mountain district - arrangement in a line - oval - I type(B), flat area - arrangement in a line - oval - I III type(C). Literature, the ways in hunting pits, the purpose of the installations, and the characters are studied and compared with those of the anthropological cases. Even though hunting pits of types A and B are constructed to hide and get protein and bone of animals for breeding, there are differences in the ways in hunting and characters. Type of A seems to be constructed only for occupation that is the standardized hunting method on a small works. However, type B is the chasing method to hunt as a group and it has various purposes including main occupation. For example, it is for improving the war skills by practicing the hunting strategies and cooperating with the people. In addition, it is for getting a sacrifice for god. The type C hunting pit is estimated that it plays a role to protect themselves from invasion. It's inferred that there are many purposes for military defense and protection of people or animals within the village. It is the reason why the construction is spread in hunting pit including various purposes in the Bronze age that originates in social and economical specialization like the increase in agricultural productivity and appearance of a chief.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.49 no.1
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• pp.59-65
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• 2023

We validated the physiological activity of Syzygium claviflorum (Roxb.) Wall. ex A.M. Cowan & Cowan (S. claviflorum) extracts (leaves, stems, fruits, and flowers) as a cosmetic ingredient. Firstly, S. claviflorum extracts removed over 80% of free radicals at various concentrations in antioxidant experiments using the DPPH and ABTS assay. In cytotoxicity experiments using human epidermal keratinocytes, S. claviflorum extracts showed low cytotoxicity. In addition, S. claviflorum extracts significantly increased the expression of keratin (KRT)1, KRT2, KRT9, KRT10, which are differentiation markers of keratinocytes, as well as genes involved in the maintenance of skin barrier function, including involucrin (IVL), loricrin (LOR), filaggrin (FLG), and claudin1 (CLDN1). In particular, the expression of FLG protein, inhibited by interleukin (IL)-4/IL-13 in atopic dermatitis, was restored by S. claviflorum extracts in in vitro experiments. Therefore, S. claviflorum extracts with excellent antioxidant efficacy and skin barrier improvement function will be useful materials for the development of future atopic dermatitis treatments and cosmetics.

• Journal of the Korean earth science society
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• v.22 no.6
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• pp.469-479
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• 2001

This study investigated the trends in the number of applicants and mean score and applicants’ responses on the test items of Earth Science in the College Scholastic Ability Test (CSAT) implemented for 3 years (1999-2001). The percentage of applicants of science track were 43.14% in 1995, but reduced through 29.5% in 2001 to 26.92% in 2002 CSAT For elective subject, about 22% of science track students applied to Earth Science II which ranked third to Biology II and Chemistry II. In 1999, test items were developed to have the expected difficulty 40 ${\sim}$ 59% (6 items) to 60 ${\sim}$ 79% (10 items). But in 2001 every 16 items were developed to have difficulty 60 ${\sim}$ 79%, which was caused by the policy of so called ‘easy CSAT’. Thus the mean score of ‘Earth Science II’ was increased from 50.26 in 1999 through 64.47 in 2000, to 67.58 in 2001. Applicants were generally very good at solving test items focusing on process skills only and familar items but poor at solving test items related to the motion of the earth and planets and sea wave, especially items calling two or more concepts. Thus special measures to cope with the decrease in applicants of science track should be provided. And it is recommended to develop test items with wider range of difficulty and to reduce test items calling process skills only. And special consideration should be given to teaching the content area with poor achievement and high actual difficulty compared to the expected.

• Archives of Plastic Surgery
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• v.34 no.5
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• pp.537-542
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• 2007

Purpose: Adipose tissue contains a population of pluripotent stem cells capable of differentiating along multiple mesenchymal cell lineages. It is well known that fat depots from different part of our body shows different nature not only in morphological aspect but also physiologic aspect. The authors compared the adipogenic potentials and osteogenic potentials of adipose stem cells from different anatomical sites of human. Methods: After laparotomy by surgery team, the authors isolated these adipose stem cells successfully from 7 men with an average age of 58, and induced differentiation along adipogenic and osteogenic lineages in vitro. On the 14th day, cells cultured in adipogenic media differentiated into adipocytes in vitro, as evidenced by positive Oil Red O staining of lipid vacuoles. On the 21st day, cells cultured in osteogenic media differentiated into osteoblasts in vitro as demonstrated by Alizarin red staining of a calcified extracellular matrix. Results: After exposure to adipogenic and osteogenic differentiation medium, subcutaneous adipose stem cells were found to possess greater adipogenic and osteogenic potentials than cells isolated from visceral adipose tissues. Conclusion: This study indicates that adipogenic and osteogenic potentials of adipose stem cells vary by their anatomical sites, with subcutaneous adipose stem cells exhibiting higher adipogenic and osteogenic potential than those isolated from visceral fat.

• Journal of Chest Surgery
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• v.41 no.3
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• pp.395-398
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• 2008

Lipoblastoma is a rare benign tumor that usually originates in children from the embryonic lipid cells of the extremities. This condition shows an early childhood occurrence, a benign nature without metastasis, a cellular composition of mainly mature lipid cells and an ability to differentiate into a simple lipoma. We have experienced a 15 month old girl who had developed a lipoblastoma in the right anterior mediastinum. Surgical resection was carried out without complications. Her postoperative course was uneventful. She has been well 6 months after the operation.

• Journal of Ginseng Research
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• v.10 no.1
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• pp.45-54
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• 1986

These studies were carried out to obtain the basic information about transformation of ginseng plant by potential vector system, utilization of opine compound by Agrobacterium sap. , and initiation of crown gall tumor callus. Crown gall tumors were induced from stem of Panax ginseng C.A. Meyer by infection of Agrobacterium tumefaciens. Therefore, it was clarified that transformation of ginseng by Ti plasmid was possible. The crown gall tumors induced by Agrobacterium tumefaciens isolated. from the soil were different in a shape, size, and growth rate. Especially, infection of ginseng by Agrobacterium tumefaciens Y104 led to the amorphic tumor, Tumor tissue derived from stem crown gall could not be continuously cultured on the medium which did not contain phytohormone, and did not form the callus even on the medium supplemented with 2,4-D. On the other hand, the root crown gall tumors formed the calli but the formation rate of callus was quite low. As for the utilization of octopine and nopaline, it was found that 3 strains of Agrobacterium app., Y104, Y110 and C58, utilized nopaline only, Y109 utilized octopine, and Y101 failed to utilize either compound.

• Journal of the Korean Geographical Society
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• v.32 no.4
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• pp.527-540
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• 1997

이 글에서는 해외지역연구에 있어 세계와와 관련한 여건 변화, 지리하계의 동향, 그리고 21세기의 새로운 지역연구에 지리학의 역할이 어떠하여야 할 것인가를 살피고자 한다. 해외지역연구는 2차대전 이후 미국을 중심으로 발달하였다. 냉전기에 세계적 우위를 유지하고 국익을 보호하기 위하여 외국 현지어 구사 능력을 포함한 해외 정보 수요가 늘어 지역연구의 발달을 보게 된 것이다. 이러한 배경 때문에 지역연구는 개성기술적(ideographic)성격을 띠게 되었다. 요즘에는, 지역연구가 주로 초국적기업, 국제 경영대학원 등을 중심으로 이루어 지고 있다. 새 지역연구는 해외시장정보 수집 등 경제적 동기로 이루어지고 있어, 경제적으로 편향되는 취약점이 있다. 세계화는 요즘 하계의 화두(話頭)로, 세계 경제와 사회에 일고 있는 이 변화를 바로 이해하는 것은 향후 지역연구의 방향을 정립하는데 매우 중요하다. 세계화는 세계 어디서나 똑같이 일어나는 동질적인 현상이 아니라, 매우 다양하고 여러 의미가 담긴 현상이다. 마치 동전에 양면이 있듯이, 세계화는 수렴과 분화를 동시에 일으키고 있는 것이다. 따라서, 국경을 개방하고 장애를 없애 하나의 동질적인 세계시장환경을 지향하는 신자유경제 논리에 바탕한 지역연구는 설득력이 약하다. 지리학이 지역연구에 기여하기 위해서는 다음과 같은 노력이 계속되어야 한다. 첫째, 해외지역을 이해하려면 공간(space)과 장소(place)연구가 필수적이라는 점을 인식하고, 둘째, 인간과 환경의 상호작용 관점에서 지리적 차이를 파악하려는 노력이 필요하다. 셋째, 지리학은 이론정립 노력을 계속해야 하며, 넷째, 그 이론들은 해외지역의 현장답사와 정보수집을 통하여 검증되어야 한다. 지리학은 일찍부터 도시, 농촌 등 미시적 수준의 연구를 수행해왔기 때문에 경험적 연구에 강하다. 다섯째, 정부와 기업 등 조직에 대한 지리학적 연구가 이루어져야 할 것이다. 경제활동 분포에 대한 조직의 역할, 소유권에 대한 정부의 규제, 생산 조직의 환경 영향 등의 연구가 그 예이다. 여섯째, 지리학의 발달을 위하여 국가, 국제적 학술 기구를 활용하는 전략이 필요하다. 국제지리학연합(IGU)에서 개발한 지리교육과정, 미국National Research Council에서 세계지리에 밝지 못한 국민을 대상으로 펴낸 지리서 등이 그 사례이다. 지역연구는 사회과학 이론과 문화연구가 서로 접목되도록 새롭게 방향이 설정되어야 하며, 지리학의 인간-환경 연구 전통이 여기에 기여할 수 있을 것이다. 그러나 지리학의 역할이 효율적이기 위해서는 지리학 자체의 담론을 다시 확립해야 한다. 지리학계에서 지난 20여년간 추구해왔듯이 일반적 법칙을 지향(nomothetic)하는 접근법을 활용해야 하며, 여타 사회과학 및 환경과학과도 긴밀한 관련을 유지할 필요가 있는 것이다.