용해실리카의 기준경도를 이용한 나노 압입시스템의 실험적 교정

이윤희 ( Yun Hee Lee ),안승민 ( Seung Min Ahn ),김주영 ( Ju Young Kim ),박찬평 ( Chan Pyung Park ),장희광 ( Hee Kwang Jang ) 대한금속재료학회(구 대한금속학회) 2015 대한금속·재료학회지 Vol.53 No.3

Indirect calibration of a nanoindentation system was performed by deriving a reference loading curve. This reference load-depth relationship was accomplished by assuming a perfect nanoindentation test on an ideal reference material; if all components in a nanoindentation system are well calibrated and the reference material has unique hardness and Young’s modulus, the indentation depth can be formulated with a function of the indentation load having two parts of contact and surrounding elastic depths. Substituting both the hardness and Young’s modulus of a fused silica into the derived function, the reference loading curve was plotted and directly compared with experimental data of the fused silica measured by two commercial nanoindenters. All indentation loading curves showed leftward shifts compared to the reference loading curve, and this is discussed, offering two reasons for the result, system compliance and indenter apex geometry.(Received January 6, 2014)

노화가 인체 중간엽 줄기세포로부터 조골세포로의 증식 및 분화에 미치는 영향

백기현,태현정,오기원,이원영,조정기,권순용,강무일,차봉연,이광우,손호영,강성구,김춘추 대한내분비학회 2003 Endocrinology and metabolism Vol.18 No.3

연구배경: 일반적으로 골다공증과 연관된 위험인자로는 연령, 폐경, 약물, 불충분한 칼슘섭취, 만성질환 및 운동부족 등이 있는데, 특히 노화가 진행할수록 골밀도가 감소하는 것은 잘 알려져 있다. 노화와 관련하여 진행되는 골소실은 조골세포 및 전구조골세포의 기능적 결핍에 의한 골형성의 감소가 주요한 요인으로 여겨지고 있다. 그 동안 연령이 조골모 세포의 양과 조골모 세포로부터 성숙조골세포로의 분화 및 증식에 미치는 영향에 대한 일부 보고들이 있었으나 아직 일치된 견해는 없는 형편이다. 방법: 다양한 연령의 사람으로부터 골수를 채취, 중간엽 줄기세포가 포함된 단핵세포를 분리한 후 조골세포로 분화하기 좋은 조건하에서 배양하였다. 대상군은다시 젊은군과 노령군으로 구분하여 다양한 변수를 비교 분석하였다. 일차배양에서는 CFU-F를 계수하여 골수내 중간엽 줄기세포의 수를 추산하였고, 칼슘측정을 통하여 기질의 무기화 정도를 비교하였다. 계대배양후 이차배양에서는 시기별로 알카리성 포스파타제 활성도를 측정하고 오스테오칼신 mRNA의 발현을 관찰하여 젊은군과 노령군 사이의 증식능 차이를 비교하였다. 또한 이차배양 시기별로 MTT 측정을 하여 양군간에 증식능 차이가 있는지 알아보았다. 결과: 1. 일차배양 15일째에 평균 CFU-F의 수는 젊은군에서 유의하게 많았다(젊은군 148.3±28.9, 노령군 54.3±9.1, p=0.02). CFU-F의 평균면적은 젊은군에서 넓은 경향을 보였으나 통계적으로 유의하지는 않았다. 2. 일차배양 17일 경과 후 양군간에 기질 칼슘 침착정도는 유의한 차이를 보이지 않았다(젊은군 103.6±50.6, 노령군: 114.0±56.5, p=NS). 3. 이차배양 10일째에 젊은군에서 알카리성 포스파타제 활성도가 고령군에 비해 유의하게 높았다(젊은군: 935.5±115.0 U/mg, 노령군: 578.4±115.7U/mg,p.0.05). 고령군에서는 시간 경과에 따른 변화가 미약했으며 전반적으로 알카리성 포스파타제의 활성도가 젊은군에 비해 낮았다. 4. 이차배양도중 오스테오칼신 mRNA의 발현은 배양시기별로 젊은군에 비해 고령군에서 더 낮은 경향을 관찰할 수 있었다. 5. 이차배양 10일과 15일에 젊은군에서 노령군보다세포증식이 유의하게 증가된 양상을 보였다(10앓 젊은군 0.73±0.05, 노령군 0.58±0.04, p=0.05, 15일; 젊은군 0.80±0.05, 노령군 0.70±0.03, p=0.05).결론: 이상의 연구에서 저자들은 노령군에서 젊은군보다 골수 내 중간엽줄기세포의 수가 적고, 노령군에서 유래한 전구조골세포의 성숙조골세포로의 증식 및 분화가 젊은군 보다 감소해 있는 것을 관찰할 수 있었다. Background: Osteoblasts originate from osteoprogenitor cells in bone marrow stroma, termed mesenchymal stem cells (MSCs) or bone marrow stromal cells. Each MSC forms colonies (colony forming units-fibroblasts [CFL-Fs]) when cultured ex vivo. There are some reports about the age-related changes of the number and osteogenic potential of osteoprogenitor cells, but any relationship has not been clearly established in humans. In this study, we counted MSCs using CFU-Fs count and examined the proliferative capacity and differentiation potential of osteoprogenitor cells. Finally, we analyzed how these parameters varied with donor age. Methods: Bone marrow was obtained from the iliac crest of young (n=6, 27.2±8.6 years old) and old (n= 10, 57.4k6.7 years old) healthy donors. Mononuclear cells, including MSCs, were isolated and cultured in osteogenic medium. In primary culture, we compared the colony-forming efficiency of MSCs between the two groups and determined the matrix calcification. When primary culture showed near confluence, the cells were subcultured. Alkaline phosphatase activity, osteocalcin expression by RT-PCR and proliferative potential by MTT assay were examined by the time course of secondary culture. Results: At the 15th day of primary culture, the mean number of CFU-Fs was significantly higher in the younger donors (young: 148.3±28.9, old: 54.3±9.1, p=0.02) and the mean size of CFL-Fs was also larger in the younger donors than the older donors. However, matrix calcification was not different between the two groups (young: 103.6±50.6, old: 114.0±56.5, p=NS). In secondary culture, alkaline phosphatase activities were significantly lower in the older donors. The younger donors showed peak alkaline phosphatase activity at day 10, while the older donors didn't showed a remarkable peak (young: 935.5±115.OU/mg, old: 578.4±115.7U/mg, p<0.05). Total cell number as a proliferative index increased progressively during the secondary culture and a significantly greater cell number was noted in the younger donors. Osteocalcin expression was generally upregulated in the younger donors, but this was not statistically significant. Conclusion: Our study shows that the number of osteoprogenitor cells is decreased during aging and that the proliferative capacity and differentiation potential of osteoprogenitor cells seem to be reduced during aging (J Kor SOC Endocrinol 18:296-305, 2003).

방광 크롬친화세포종과 동반된 배뇨후 벼락두통

하윤석,강성진,허소영,이지현,김민정,김종국,김광수 고신대학교 의과대학 2009 고신대학교 의과대학 학술지 Vol.24 No.1

Thunderclap headache is a hyperacute, severe headache that is so named because the pain strikes suddenly and severely, and is sometimes a sign of a medical emergency. We report a case of pheochromocytoma in the urinary bladder in a 48-year-old woman who presented with recurrent thunderclap headache after voiding and exercise. So we think thunderclap headache during or immediately after micturition may be an important diagnostic clue of bladder pheochromocytoma.

급성 뇌경색 환자에서 경색 위치가 심근 효소치 상승에 미치는 영향

윤경호,박현영,박성욱,장혁,김요식,조광호,유남진,김남호,오석규,정진원 圓光大學校 醫科學硏究所 2003 圓光醫科學 Vol.18 No.2

대장게실염 -18 예-

김광연,차귀현,이영희,유경수 대한대장항문학회 1986 Annals of Coloproctolgy Vol.2 No.1

대장 및 직장암 환자에서 말초혈 및 문맥혈의 암태아성항원값(CEA)의 비교분석

문영준,김홍대,한원곤,김광연 대한대장항문학회 1996 Annals of Coloproctolgy Vol.12 No.3

ERP시스템에서 생산시스템 설계(A사 사례연구 중심으로)

윤영도,양광모,강경식 明知大學校 産業技術硏究所 2002 産業技術硏究所論文集 Vol.21 No.-

As business operations are globalized, the management information system which have been developed to support individual tasks in many companies are focused on the ineffectiveness. That in because the entire business transactions including production, accounting, personnel management, and logistics need to be integrated with a global perspective. To meet these requirements, many enterprises are planning or adopting the ERP package which has been recently assailable with the help of advanced information technologies. The target company of this study goes ahead with plan to adopt ERP systems. Hereupon, I want to present the issues which should be considered in the process of ERP system implementation. This study focuses on the manufacturing system, but it also discusses important issues on the selected business area. This study covers the material benefits and functionalities of ERP package as well as the importance of studying and understanding on business process, organization change management, and information technology. And this case study swart with a long-term plan and consider its own unique characteristics and environmental factors. But it is regrettable that I can not make a comparative analysis with other systems because the ERP system is still on the introductory stage for the company studies and the benefits have net been realized yet. Another limitation of this research is its narrow scope of study in which only the raw material inventory system for a single company is covered. In the future, however, ERP system would be adopted by many corporations, which would help us to launch a comparative study on the results of ERP system implementation as a future direction of research.

TiNi 섬유가 강화된 형상기억복합재료에 있어서의 응력해석

윤두표,김광영,박영철 東亞大學校 大學院 1998 大學院論文集 Vol.23 No.-

The shape momery alloy material is producted by the powder metallugy with TiNi alloy, before its mechanic properties are resulted by the stress analysis. Because the result of the stress analysis and that of the tensile test is similar, we would properly design the volume fracton and the strength of the shape memory alloy material.

공간구성 및 복지지원 서비스 측면에서 살펴본 공공업무시설의 시설적·제도적 개선 방안 : 전국 44개 시청 및 구청의 실태조사를 통하여

윤영삼,이인기,강병근,김상운,성기창,박광재 한국의료복지시설학회 2006 의료·복지 건축 Vol.12 No.2

The purpose of this study is to suggest institutional reformation of public office facilities by analysis the status of services on welfare for the aged and disabled. For this study, we have researched and analyzed on two different aspects. The aspects are space composition of public office facilities, welfare systems and service support within region. And we can get the following important points as conclusion; ① We need to consider on not only access for public office facilities site hut also the connection on business such as block plan on zone and connection between quarters. Architectural plan has to be considered. ② Most of the public office facilities use human service resources as a supporting system for shortage of convenient facilities. Variety of welfare services are required. ③ We need to secure various programs and space for local peculiarities and social demand.

재생골재를 사용한 콘크리트의 특성에 관한 실험적 연구

최광윤,배수환,정재동,김한철,최영화 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.2

The purpose of this experiment is an experimental study on recycling of waste concrete and suggest a possibility of the Recycled Aggregate Concrete after establishing some kinds of experimental properties of concrete. Therefore, this study compared and investigated properties of natural aggregate concrete and recycled aggregate concrete by replacing the ratio of recycled aggregates under the absorptions, compressive strengths and chemical resistances. As the result, the compressive strength and the chemical resistance of Recycled Aggregate Concrete is lower than the natural aggregate concrete. If was concluded that the properties of the recycled aggregates and lower than natural aggregates.