• Proceedings of the KSMRM Conference
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• 2005.09a
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• pp.47-47
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• 2005

• Journal of Korean Ophthalmic Optics Society
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• v.18 no.4
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• pp.533-540
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• 2013

Purpose: To investigate the synaptic pattern of NMDA glutamate receptor subtype NMDA R1 on the dendritic arbors of ON-OFF direction-selective retinal ganglion cells (DS-RGSs) in developing [(5,10) days postnatal (PN)] mouse retina. Methods: ON-OFF DS-RGCs were injected with Lucifer yellow and the cells were identified by their characteristic morphology. To identify glutamatergic excitatory input from bipolar cell, we used a marker for the membrane traffic motor protein kinesin. Results: We identified DS-RGCs in P5, and P10 mouse retina. The immunofluorescence labeling of NMDA R1 was most prominent in the IPL. Our results showed that their presence upon the entire dendritic arbor of ON-OFF DS-RGCs is without any evidence of asymmetry, which would predict direction selectivity. Conclusions: The glutamatergic input from bipolar cell reveals symmetry pattern in all periods of P5, and P10. The results may suggest that direction selectivity not lies in the specific pattern of NMDA R1 receptors.

• The Korean Journal of Mycology
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• v.39 no.1
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• pp.85-87
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• 2011

The opportunistic human pathogen Candida albicans has the ability to convert from yeast-form to pseudohyphal or true hyphal form. The morphological transition is considered as an important virulence factor, because the decrease or lack in dimorphism causes the reduction of virulence. Our previous study revealed that the disruption of dual specificity kinase gene caused the reduction of dimorphism in C. albicans. Therefore we tested the effect of dual specificity kinase in virulence using mouse model. The mean survival time for kinase-defective strains was about 15 days in comparison with those of wild-type, 3.9 days. Moreover the fungal burden on kidneys for kinase-defective strains was decreased by ten-fold than that for wild-type. These results suggest possible involvement of dual specificity kinase in a novel signal transduction pathway for morphological transition and virulence of C. albicans.

• International Commerce and Information Review
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• v.19 no.1
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• pp.235-256
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• 2017

This study is to analyse how trust and asset specificity among partner firms affect on performance of international joint venture(IJV). Especially, the analysis was mainly based on a quadratic model. While it assumes that the previous studies was based on linear model in the relationship between trust, asset specificity and the performance, this study proceeds a empirical analysis by setting up a hypothesis; it would be quadratic relationship between trust, asset specificity and performance which are based on social capital theory and transaction cost theory. The survey was held with 74 manufactures who were established as an IJV by Korean and foreign firms together. In the result of the empirical analysis, trust shows an inverted U-shaped relationship with IJV performance. Also, asset specificity shows the U-shaped relationship with IJV performance. The results suggest that it needs to control and maintain the trust level among the partners in order not to lose an appropriate control caused by too much trust. In order to minimize the cost generated by asset specificity and to transform it into positive impact, it needs a control and the operation of monitoring system on the opportunistic action of the partners. Furthermore, it needs to keep organizational flexibility and innovativeness to continuously develop new capabilities.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2002.11a
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• pp.114-114
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• 2002

포유동물에서 뇌와 부신에서 합성.분비되는 카테콜아민(Catecholamine, CA)계 신경전달물질인 dopamine(DA), norepinephrine(NE), epinephrine(E)은 체내 각종 생리현상의 조절에 필수적이며, 생식과 관련지어서는 시상하부-뇌하수체 간 GnRH-gonadotropin 호르몬 축의 활성을 조절하는 기능 외에도 번식과 관련된 여러 행동양식을 조절함이 잘 알려져 있다. 본 연구는 CA 생합성 효소들인 tyrosine hydroxylase(TH), dopamine beta-hydroxylase(DBH), phenylethanolamine-N-methyltransferase(PNMT)의 유전자 발현에 미치는 sex steroid의 영향을 조사하였다. 성숙한 암컷 횐쥐(SD strain)의 난소를 제거하고 1주 경과 후 vehicle(sesame oil; OVX+Oil 실험군) 또는 estradiol 17$\beta$(235ug/m1; OVX+E$_2$실험군)이 든 silastic capsule(길이 14mm; 내경 1.55mm; 외경 3.125mm)을 48 시간 동안 처리한 뒤 희생시켰다. 적출된 조직으로부터 RNA를 추출한 후 semi-quantitative RT-PCR을 시행하였다. (i) TH의 발현 정도는 OVX+Oil 군에서는 시상하부) substantia nigra(SNc)) 부신 순으로, OVX+E$_2$군에서는 SN글 부신) 시상하부 순으로 나타났다. TH 발현에 미치는 estradiol의 효과로 SNc과 부신에서는 유의한 증가를 보인데 비해 시상하부에서는 유의한 감소를 관찰하였다. (ii) DBH 발현 정도는 OVX+Oil군에서는 SNc> 부신> 시상 하부 순으로, OVX+E$_2$군에서는 부신＞ SNc＞ 시상하부 순이었다. DBH 발현에 미치는 estradiol의 효과로 SNc에서는 유의한 감소, 부신에서는 유의한 증가, 그리고 시상하부에서는 통계적 유의성은 없으나 감소하는 경향을 보였다. (iii) PNMT의 발현의 경우 SNc와 시상하부에서는 기보고된 바와 같이 alternative splicing에 의해 110bp 차이의 크고 작은 두 형태의 cDNA(PNMTI & PNMTs)가 증폭되었으나 부신에서는 작은 cDNA 만이 관찰되었다. PNMTs의 발현 정도는 OVX+Oil군과 OVX+E$_2$군에서 공히 부신＞ 시상하부＞ SNc 순이었고, PNMTI의 발현은 SNc가 시상하부 보다 다소 높은 경향이었으나 유의성은 없었다. PNMTs 발현에 미치는 estradiol의 효과로 SNc에서는 유의한 감소, 부신에서는 유의한 증가, 그리고 시상하부에서는 통계적 유의성은 없으나 증가하는 경향을 보였다. 본 연구에서는 CA 생합성 효소들의 유전자 발현의 조절에 미치는 estrogen 의 영향이 세포 기원이 neural crest cell인 부신 수질은 물론 뇌의 상이한 지역간에서도 조직특이적임을 관찰하였다. 이러한 결과는 각 조직에서의 estrogen 수용체 유형의 차이 혹은 작용 모드와 각 효소 유전자 발현 사이에 중요한 상관관계가 있음을 시사한다.

• The Korean Journal of Zoology
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• v.32 no.1
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• pp.34-39
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• 1989

Ouabain, strychnine sulfate, caffeine sodium benzoate and chlorpromazine hydrochloride were introduced intraperitoneally into male mice for 7, 14 and 21 days to induce the changes in the relative percentages of lactate dehydrogenase isozymes. The five isozymes in brain, heart and kidney tissues were electrophoresed on cellulose acetate strip and subjected to densitometry. Ouabain caused a drastic increase of B$_4$isozymes only in brain tissues. The two stimulants altered the relative percentages of $A_4$and B$_4$isozymes conspicuously in brain tissues, whereas virtually no redistributions of five isozymes were occurred by the depressant except B$_4$isozymes in brain and heart tissues. On the basis of these observations, it might be suggested that the changes in intracellular concentration of sodium and calcium ions are not the cause of the isozyme redistributions and that Organization of plasma membrane could be one of the factors involved in the tissue specificity of lactate dehydrogenase isozymes in vertebrates.

• Proceedings of the Korea Association of Information Systems Conference
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• 1997.10a
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• pp.503-525
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• 1997

정보시스템 아웃소싱(outsourcing)의 적용 범위와 그 규모가 증대함에 따라, 아웃 소싱은 정보시스템의 관리에서 근본적인 이슈로 등장하게 되었다. 정보시스템 아웃소싱의 중요성이 인식되었으나, 그에 대한 실증적 연구는 매우 미흡한 설정이다. 본 연구의 주요 목적은 정보시스템 아웃소싱에 있어 고객회사(client firm)와 서비스 제공업자(vendor)간의 관계의 성공 및 실패에 영향을 미치는 요인을 조사하는 것이다. 본 연구의 연구 모델은 관 계적거래이론(relational exchange theory), 커뮤니케이션 행동(communication behavior), 거래비용분석(transaction cost analysis) 등의 조직간관계(interorganizational relationship) 이론에 기반을 두고 작성되었다. 미국의 207개 회사의 정보시스템 아웃소싱 설문조사에 의 하여 다음과 같은 연구결과가 도출되었다. (1) 서비스 제공업자의 능력(vendor capability), 관계결속성(solidarity), 관계지속성(continuity expectation), 유연성(flexibility), 서비스업자의 활동에 대한 모니터링(monitoring of the vendor), 참여도(participation) 등이 아웃소싱 관 계의 성공과 양의 상관관계를 가지고 있으며, (2) 역할연합도(role integrity), 자산특이성 (asset specificity) 등은 아웃소싱 관계의 성공과 음의 관계를 가지고 있는 것으로 나타났 다. 이 결과에 의하면, 비관계적 거래(discrete exchange) 보다는, 관계적 거래(relational exchange)에 기반을 두어 아웃소싱 관계를 운영하는 것이 아웃소싱의 성공적인 구현을 필 수적으로 보여진다. 이 연구 결과를 기초로 하여 아웃소싱 대상 업무의 선택, 서비스 제공 업자의 선택, 그리고 아웃소싱 관계의 지속적인 관리를 위한 지침을 제시하였다.

• Korean Journal of Head & Neck Oncology
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• v.19 no.1
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• pp.21-24
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• 2003

Objectives: In this report, we confirmed the distributed pattern of ALA and ALA-methylester in normal and tumor-bearing region. Materials and Methods: ALA and ALA-methylester were administered to nude mouse by intratumoral, subcutaneous and intravenous injection. After injection, the fluorescence in normal and tumor region was measured by LESA (laser electronic spectrum analyzer). Results: The tumor-specificity of ALA and ALA-methylester was shown in the case of intratumoral injection. In all case, the fluorescence caused by ALA and ALA-methylester was maximally increased in 2 hours after injection. Then while the fluorescence level was rapidly decreased to control level in normal region, it was still remained in tumor region. Conclusion: According to this result, The intratumoral injection was more efficient administration method for PDT/PDD than subcutaneous and intravenous injection.

• Biomedical Science Letters
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• v.4 no.1
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• pp.57-63
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• 1998

The objectives of this study were to produce polyclonal antibody to adipocyte plasma membrane (APM) proteins isolated from pig, and to investigate its tissue specificity. Plasma membrane proteins from adipocyte, brain, heart, kidney, liver and spleen were isolated using a self-forming Percoll gradient. Sheep (40kg) was immunized three times at three week interval with the purified APM proteins. Blood was taken from non-immunized sheep (NS) and from immunized sheep at 10 (AS-1), 12 (AS-2), and 14 (AS-3) days after the third immunization. Antisera titers and cross-reactivity against other tissues were determined by enzyme-linked immunosorbent assay (ELISA). Antisera reacted strongly to APM proteins showing detectable amounts of antibody at 1：81,000 dilution. And antisera showed much stronger reactivity to APM proteins than any other tissue plasma membrane proteins. Furthermore, tissue specificity of antisera against APM was reconfirmed by immunoblotting using anti-sheep immunoglobulin G-horseradish peroxidase conjugate as a secondary antibody Antisera to APM proteins showed adipocyte specificity compared with other tissues. In conclusion, polyclonal antibody against APM proteins isolated from pig was developed successfully in our laboratory, and these antisera showed tissue specificity with APM.

• Applied Microscopy
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• v.31 no.4
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• pp.367-374
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• 2001

Leaves of two developmental stages of Salsola species, young and mature, were examined to reveal the structural and functional relationships in the photosynthetic tissue using anatomical and ultrastructural criteria. Both young and mature leaves had Kranz anatomy of the Salsolid type with two layers of chlorenchyma on the leaf periphery: an outer layer of palisade mesophyll cells and an inner layer of compact bundle sheath cells with centripetally arranged organelles. The chlorenchyma was continuous in young leaves , while it was discontinuous in mature leaves. The main vascular bundle occupied the central position in the leaf. but the small peripheral vascular bundles were in contact with the chlorenchyma. Structural dimorphism of chloroplasts was obvious in bundle sheath cells of mature leaves exhibiting noticeable grana reduction, whereas mesophyll cell chloroplasts had well developed grana in all cases. Plasmodesmata were less numerous and rather simple in young leaves relative to well-developed secondary plasmodesmata of the later stage. According to the current data, features of two stages of Salsola leaves corresponded to NADP-ME bio-chemical subtype on the basis of photosynthetic cell ultrastructure. Implications of developing such anatomical and ultrastructural data of Sulsola species and biochemical characteristics reported in other C-4 species have been discussed.