섬유주세포에서 Dipyridamole이 활성산소종과 산화스트레스에 미치는 영향

이근우,김재우,Keun Woo Lee,Jae Woo Kim 대한안과학회 2013 대한안과학회지 Vol.54 No.3

Purpose: To investigate the effects of dipyridamole (DPD) on the production of reactive oxygen species (ROS) and oxidative stress in cultured human trabecular meshwork cells (HTMC). Methods: Antioxidant activity of DPD was determined by DPPH assay. Primarily cultured HTMC were exposed to 0, 20, and 50 μm DPD using serum-deprived media. The effect of DPD on the production of ROS was assessed with the DCHFDA assay. The effect of DPD on the t-butyl hydroperoxide (tBHP)-induced oxidative stress was assessed with resazurin assay. Results: DPD showed significant antioxidant activity. DPD significantly decreased the production of ROS (p < 0.05) and improved cellular activity significantly after treatment with t-BHP (p < 0.05). DPD did not affect the generation of nitric oxides. Conclusions: DPD suppressed the formation of ROS and possessed cytoprotective activity against the oxidative stress in HTMC.

사료내의 아연과 칼슘이 돼지 부전각화증의 발생에 미치는 영향

이근우,이현범,Lee Keun-Woo,Lee Hyun-Beom 대한수의사회 1984 대한수의사회지 Vol.20 No.1

Present experiments were conducted in order to clarify the effect of dietary low zinc and excess calcium on the zinc and calcium concentrations of serum and feces, and to show the therapeutic effect of external application of zinc or soybean oil on the sk

Rat에 있어서 ethanol투여가 체조직의 무기질 함량에 미치는 영향

이근우,이현범,Lee, Keun-woo,Lee, Hyun-beom 대한수의학회 1989 大韓獸醫學會誌 Vol.29 No.1

This study was designed in order to clarify the effect of ethanol drinking on the mineral contents on liver, kidney, muscle and hair. Forty-five rats were divided into 2 groups and a control group. The control group received tap water and the other 2 groups were given 8% and 40% ethanol as drinking source. Liver, kindney, muscle and hair samples were taken and analyzed for zinc, calcium and copper contents by atomic absorption spectrophotometric methods. The results obtained are summrized as follows; 1. The zinc content of muscle showed significant (p<0.01) decrease in both groups. 2. The calcium content of hair showed significant (p<0.1) increase in 8% ethanol group. 3. The copper contents of kidney and muscle in 8% ethanol group and liver in 40% ethanol group showed significant (p<0.1) decrease.

수지접합 수복물용 합금의 피착면처리에 따른 결합력에 관한 실험적 연구

이근우,Lee, Keun-Woo 대한치과보철학회 1991 대한치과보철학회지 Vol.29 No.1

This study investigated the effects of surface treatment on the tensile bond strength of resinbonded prosthesis. The Rexillium III specimens were treated with $50{\mu}m\;Al_2O_3$ blasting. Type IV gold alloy specimens were treated with $400^{\circ}C$ heating and tin plating method. All specimens were bonded with MBAS composite resin cement and followed by immersion test into the $37^{\circ}C$ water bath for 7 days. The specimens were debonded in tension with an Instron machine and observed with SEM. The modes of failure were recorded also. The following conclusions were obtained : 1. The tensile bond strength decreased in following order. $50{\mu}m\;Al_2O_3$ basted Resillium III group, Type IV gold alloy group treated with $400^{\circ}C$ heat and tin plating type IV gold alloy group, and statistical significant differences were observed(p<0.05). 2. The tensile bond strength decreased in all groups after 7 days immersion test, but statistical significant differences were observed in Rexillium III specimens only. 3. The sharp and irregular surface were observed in Rexillium III, but $400^{\circ}C$ heat treated and tin plated groups had round and broad surface in SEM. 4. The models of bond failure were cohesive-adhesive failure mainly.

사료내 카드뮴 첨가가 체조직과 피모의 카드뮴, 아연, 철 및 구리함량에 미치는 영향

이근우,이현범,Lee, Keun-woo,Lee, Hyun-beom 대한수의학회 1987 大韓獸醫學會誌 Vol.27 No.2

This thesis was designed to find out whether the cadmium content of hair in living animals reflects the status of cadmium accumulation in internal organs or muscles so that this status can be used as a diagnostic method. Forty-five rats were divided into 4 experimental groups and one control group. The control group received a basal diet which contained zinc $100{\mu}g/g$, iron $80{\mu}g/g$ and copper $135{\mu}g/g$. The experimental group received experimental diets sllpplemented with 1, 10, 100 or $1,000{\mu}g/g$ cadmium as cadmium sulfate. Rats were dissected on the 28th or 56th day of experimental periods and tissues, blood and hair samples were taken, dried and burned to ash and analysed. The cadmium, iron zinc and copper concentrations were measured with an atomic absorption spectrophotometer. In addition feed efficiency and hematological changes were observed. The results obtained can be summerized as follows: A marked decrease in feed intake, weight gain and feed efficiency were observed from 1 or 2 weeks of experimental periods, which was in accordance with the dosage and periods. The cadmium contents of kidney, liver, spleen and muscle were significantly increased in all experimental rats; the accumulation was marked in kidney and liver tissues. It was shown that the cadmium contents of hair reflects the cadmium accumulation in internal organs and muscle; the higher the cadmium levels of diet and of rat tissues, the higher the cadmium content of hair. In the $100{\mu}g/g$ group of rats erythrocyte counts and. hemoglobin concentrations were decreased. A significant(p<0.01, p<0.05) increase in iron contents of kidney, liver and muscle was observed in 10, 100, $1,000{\mu}g/g$ groups of rats on the 28th day of experiment. A significant (p<0.01, p<0.05) increase in zinc contents of kidney, liver and muscle was observed in all experimental rats. On the other hand, serum zinc concentration was decreased. A significant(p<0.01) increase in copper contents in the liver was observed on the 28th day in $100{\mu}g/g$ and $1,000{\mu}g/g$ groups of rats. From these results it may be concluded that the analysis of hair for cadmium is a useful diagnostic approach for the cadmium status of internal organs and muscle in living animals.

도저용 착시 도재-금속 개면에서의 원소이동에 관한 실험적 연구

이근우,이호용,Lee, Keun-Woo,Lee, Ho-Yong 대한치과보철학회 1987 대한치과보철학회지 Vol.25 No.1

This study was undertaken to observe the elemental transition of Interface depending on different pretreatment methods, the number of filings, the kinds of porcelain powders and the various alloys in ceramo-metal restoration. The materials used in this study were Pors-on $4^{(R)}$ and Ceramco porcelain powder to compare the differences depending on the pretreatement methods and the number of firings. Ceramco porcelain powder and Vita porcelain powder were used to compare the differences of elemental transition depending on the porcelain powders. The $Parasil^{(R)},\;PGV^{(R)}$ and Pors-on $4^{(R)}$ as Pd-Ag alloy were used to compare the difference of elemental transition depending on the various alloys. The pretreatment methods were : no treatment, treatment under vacuum and air, treatment with 50 % hydrofluoric acid and double heat tretament. The number of firings were 3, 5 and 7 repeated firings All specimens were observed by SEM and concentration of elements were analyzed quantitatively with EPMA The results of this study were obtained as follows : 1. In the groups of air-treatment, concentration of Sn were the highest and widest. A high concentration of In were in the groups of vacuum and air treatment. 2. There were no significant differences in concentration of Sn between the group of vacuum, 5 minutes hydrofluoric acid and double heat treatment. (p>0.05) 3. As the period of time of hydrofluoric acid treatment increased, not only were the trace elements reduced but the main components such as Pd and Ag were also reduced. 4. Concentration of Sn and In increased and diffused with repeated firings but 5 repeated and 7 repeated firings groups had no significant differences. (p>0.05) 5. Sn were more concentrated in the group of Ceramco porcelaion powder than Vita porcelain powder. 6. The higher concentration of trace elements in the alloy, the more increasing concentration of Sn and In in the interface.

염화제이철 용액을 이용한 베릴륨동 기판의 식각 특성

이근우(Lee Keun Woo),이병욱(Lee Byung Wook),이태성(Lee Tae Sung),이종하(Lee Jong Ha),이재홍(Lee Jae Hong),김창교(Kim Chang Kyo) 대한전기학회 2006 대한전기학회 학술대회 논문집 Vol.2006 No.10

구리와 강철의 성질을 혼합한 것과 같은 우수한 성질을 갖고 있어서 열전도율이 좋고 내마모성이 뛰어난 베릴륨동 기판(BeCu foil)에 대한 식각 특성에 관하여 연구하였다. 일반적으로 베릴륨구리에 대한 식각용액은 염화제이철(FeCl₃)이 널리 알려져 있으며, 이 용액은 농도와 온도에 따라 식각시간이 달라지게 되어 식각되는 면의 상태가 영향을 받게 된다. 염화제이철의 농도를 변화시켜 본 결과 염화제이철의 농도가 증가할수록 식각률이 증가하였고, 염화제이철에 염산(HCl)을 첨가한 결과 식각률이 증가함을 알 수 있었다. 이는 염화제이철의 성분 중에서 염산(HCl)의 농도가 식각률에 영향을 미치고 있음을 나타낸다. 또한 영화재이철의 용도가 40℃ 일때 식각륜이 가장 우수하며 식각되는 면의 상태가 매우 양호해지고 식각되는 면의 각도도 수직에 가까워진다.

은행의 장외파생상품 거래 지원을 위한 의사결정지 원시스템 설계 사례

이근우(Lee Keun-Woo),양근우(Yang, Kun-Woo) 한국IT서비스학회 2011 한국IT서비스학회 학술대회 논문집 Vol.2011 No.5

DSS는 금융상품의 가치를 정교하게 모델링하고, 이를 토대로 거래의사결정을 내림으로써 수익을 창출하는 금융시장 참가자들에게도 매우 중요한 역할을 하고 있다. 일반적으로, 금융상품가치의 모델링과 이의 분석은 고난도의 수학적 이론과 고밀도의 계산을 필요로 하는 매우 전문적인 작업으로, 이론적 기반이 부족한 거래담당자가 이를 효과적으로 수행할 수 있도록 지원하는 DSS의 역할은 성공적인 거래의사결정을 위해 반드시 필요한 요소 중 하나이다. 그럼에도 불구하고 아직까지 많은 금융기관들의 거래지원시스템은 금융상품 모델링의 지원보다는 거래업무 프로세스의 자동화 또는 대용량 거래 데이터의 효과적인 관리 등 데이터 처리에 대한 이슈를 중심으로 구축되고 있다. 또한, 시스템의 안정성을 위해 내부구조가 공개되지 않는 닫힌 시스템(closed system) 형태로 개발되는 경우가 대부분이기 때문에, 금융시장의 변화에 적절히 대처하기 어려운 경우가 많다. 이러한 기존 거래지원시스템의 한계를 극복하기 위해, 본 논문에서는 금융상품 모델링을 효과적으로 지원하고 시장 변화에 유연하게 대처할 수 있는 DSS 아키텍처를 제안한다. 특히, 국내의 대표적 시중은행에서 수행된 장외파생상품거래 지원시스템 구축 사례를 통해 실증적 관점에서 고려해야 할 사항들을 중심으로 제안 아키텍처의 장점과 한계점 등을 분석하였다.

해상교통사고처벌의 몇 가지 문제 : ‘광안대교 충돌’ 사건의 평석을 통하여

이근우(Keun-woo Lee) 한국형사정책학회 2020 刑事政策 Vol.32 No.2

얼마 전에 러시아 선박이 접안된 선박들을 충격하고 달아나다가 광안대교를 충격한사건에 대한 항소심이 선고되었다. 기존의 판례에 따르면 대상판결은 매우 자연스러워 보이지만 이론적 시각에서는 이 사건에 적용된 법률과 판례에는 여러 문제가 숨어 있는데, 그 배후에는 형법에서의 결과책임사상의 문제와 책임주체의 선별 문제가있다. 어쩌면 결과책임사상이야 말로 거의 인류의 역사만큼이나 오래된 것으로서 古代에는 천재지변에 대해서도 책임을 져야 하는 자가 있었을 만큼 극복되기 힘든 문제라고 할 수 있다. 근현대의 형법학이 이를 극복하고자 시도하였고, 적어도 객관적 행위와 결과 사이의 과학적 인과관계를 중심으로 논의되는 교과서에서만큼은 극복된 것으로 여겨지지만, 실제로는 많은 사람들의 사고 속에서는 제거되기 힘든 것으로서특히 중한 결과를 초래한 과실범 혹은 결과적 가중범의 영역에서는 여전히 그 위력을 발휘하고 있는 것으로 보인다. 형사책임 주체의 선별 문제는 주로 특별의무자에 대한 것이다. 많은 법률에서 특정의무를 부과하고 그 위반을 처벌하고 있는 경우가 많은데, 그러한 의무를 지는 자가자기의 지배영역 내에서 당해 의무를 충분히 이행할 수 있는 자라면 타당한 규정이지만, 오늘날의 거대 규모의 분업적 산업 환경에서 법률상의 특별의무자에게 그 의무 이행을 위한 실질적 권한이 없어서 단독으로는 의무이행이 불가능함에도 불행한 결과가 발생하면 언제나 그가 형사책임을 져야 한다면, 이는 과거 서구에서의Whipping boy에 다름없기 때문이다. 불행한 결과의 방지는 상징적인 중벌이 아니라, 우리가 알고 있는 안전의무의 이행을 감독하는 제도의 세밀한 수립과 시행에 있을 것이다. There are issues of accountability in the criminal law and selection of responsible parties. Perhaps the result-response ideology is almost as old as the history of mankind, and it can be said that it was a difficult problem to overcome because there were some people who were responsible for the natural disaster in the old days. Modern criminal law has attempted to overcome this, and at least it seems to have been overcome in textbooks that focus on the scientific causal relationship between objective action and outcome, but in reality it is difficult to remove it from the heads of the majority of people. It still seems to be exerting its power in the domain of the negligent or consequential aggravator. The problem of screening the subject of criminal responsibility is still a problem I m still concerned about, but to relate to today s topic, it s about a special duty officer such as Captain . There are many cases in which many laws impose certain obligations and punish their violations-in theory of criminal law, so-called duty offenders, but if those who have such obligations are those who can fully fulfill their duties within the scope of their control, It can be said that there is no problem, but in today s large-scale, decentralized industrial environment, the special man in law does not have the actual authority to fulfill the obligation, so that even if the unfortunate result occurs even if it is impossible to fulfill the obligation alone, he must be held criminally responsible. If so, this was a whipping boy in the past (a boy who was beaten, a system that existed until the early modern age), and the boy who was beaten was the role of a hawk when he did something bad, such as skipping a class. This is because there is an anecdote for the sale of the selling arm that earns the hawk.

MEMS 기술을 이용한 프로브 카드의 탐침 제작

이근우(Keun Woo Lee),김창교(Chang-Kyo Kim) 제어로봇시스템학회 2008 제어·로봇·시스템학회 논문지 Vol.14 No.4

Tips of probe card were fabricated using MEMS technology. P-type silicon wafer with SiO2 layer was used as a substrate for fabricating the probe card. Ni-Cr and Au used as seed layer for electroplating Ni were deposited on the silicon wafer. Line patterns for probing devices were formed on silicon wafer by electroplating Ni through mold which formed by MEMS technology. Bridge structure was formed by wet-etching the silicon substrate. AZ-1512 photoresist was used for protection layer of back side and DNB-H100PL-40 photoresist was used for patterning of the front side. The mold with the thickness of 60㎛ was also formed using THB-120N photoresist and probe tip with thickness of 50㎛ was fabricated by electroplating process.