모유 황달

崔仲煥 대한의학협회 1994 대한의학협회지 Vol.37 No.7

동적 크리프 컴플라이언스를 이용한 완화시간분포의 근사계산법

최중환,Choi, Joong Hwan 한국섬유공학회 2014 한국섬유공학회지 Vol.51 No.5

The relaxation time spectrum is a very effective parameter for transforming material functions even with a limited amount of data. The spectrum also helps in understanding the relaxation behavior of polymers at the molecular scale. In this study, a relaxation time spectrum based on Marin-Graessley's dynamic compliance model was calculated using Fuosso-Kirkwood's complex analysis. The resulting model could successfully describe the viscoelastic behavior of mono-disperse polystyrene. However, it was clear that a more effective numerical analysis method was needed to obtain more accurate parameter values.

조산아의 집중치료

崔仲煥 中央醫學社 1995 中央醫學 Vol.60 No.4

Comparison of Paraquat Actions on Oxygen Radical Generation and Lipid Peroxidation between Submitochondrial Particle and Microsome of Mouse Liver

최중환,김용식,박종완,정명희,윤종구,Choi, Jung-Hwan,Kim, Yong-Sik,Park, Jong-Hwan,Chung, Myung-Hee,Yunn, Chong-Ku The Korean Society of Pharmacology 1991 대한약리학잡지 Vol.27 No.2

Paraquat 독성작용에 있어서 mitochondria의 잠재적인 역할을 평가하기 위하여, 이 약물의 산소 radical 생성과 지질과산화 반응에 미치는 영향을 mouse간의 submitochondrial particle 과 microsome에서 비교하여 보았다. Submitochondrial particle 사용시 NADH를, microsome 사용시 NADPH를 전자공여체로 이용한 경우 paraquat는 두 분획에서 superoxide anion과 hydrogen peroxide의 생성을 증가시켰다. 동일한 조건하에서 paraquat는 hydroxyl radical의 생성을 시사하는 methional로 부터 ethylene의 생성을 증가시켰다. 그러나, paraquat에 의한 이들 각각의 효과는 microsome에서 보다 submitochondrial particle에서 약간 낮았다. 한편, 두 분획 모두에서 paraquat는 지질과산화 반응을 촉진시켰다. Submitochondrial particle과 microsome에서의 Paraquat에 의한 지질과산화반응은 i) 두 분회에서 지질과산화는 SOD에 의해서 부분적으로 억제됨을 보였고, DETAPAC(iron chelator)에 의해서는 완전히 억제되었고, catalase와 hydroxyl radical scavenger에 의해서는 억제되지 아니하였으며, ii) 반응내 $ADP-Fe^{3+}$ 첨가로 paraquat에 의한 지질과산화는 더욱 증가되었지만 methional로 부터 ethylene 생성은 감소하여 hydroxyl radical 생성과 지질과산화 사이에는 상관성이 없음으로 보아 같은 기전을 통해 촉진됨을 알 수 있었고 이러한 촉진작용은 perferryl ion을 통하여 일어나리라 추측되었다. Submitochondrial particle에서 paraquat에 의해 촉진된 산소라디칼 생성과 지질과산화 반응은 p-hydroxymercuribenzoate(NADH dehydrogenase 억제제)에 의하여 억제되었으나 다른 respiratory chain 차단제들에 의해서는 거의 영향을 받지 않음으로 보아 mitochondria에서의 paraquat의 redox-cycling은 CoQ 보다는 NADH dehyrogenase와 관련이 있음을 시사하였다. 이상의 결과로 보아 산소 radical의 생성과 지질과산화를 유도하는 paraquat의 redox-cycling은 microsome에서와 마찬가지로 mitochondria에서도 일어나며, 이결과 생체내에서의 paraquat의 독작용에 관여함을 짐작할 수 있다. In order to evaluate a potential role of mitochondria in the mediation of toxicity of paraquat (PQ), submitochondrial particle and microsome of mouse liver were compared by oxygen radical generation and lipid peroxidation. With NADH in submitochondrial particle and NADPH in microsome as electron donors, PQ stimulated production of superoxide anion and $H_2O_2$ in both fractions. Under the same conditions, PQ enhanced the generation of ethylene from methional suggestiong stimulation of OH production by PQ. But these effects by PQ were somewhat lower in submitochondrial particle than in microsome. In addition, lipid peroxidation(measured as MDA production) was stimulated by PQ in both fractions. The stimulation of lipid peroxidation in both fractions seemed to occur by the same mechanism probably through perferryl ion. This was supported by the following findings: i) The lipid peroxidation in both fractions was partially inhibited by SOD and completely inhibited by DETAPAC(an iron chelator) but not by catalase or OH scavenger. ii) Addition of $ADP-Fe^{3+}$ further increased PQ-induced lipid peroxidation but decreased ethylene production from methional suggesting no correlation between OH production and lipid peroxidation. The redox-cycling of PQ in mitochondria appeared to be linked to NADH dehydrogenase, not to CoQ since all of the observed stimulations by PQ in submitochondrial particle were inhibited by p-hydroxymercuribenzoate(a NADH dehydrogenase inhibitor) but not affected by other respiratory chain blockers. The above results demonstrate that redox-cycling properties of PQ leading to oxygen radical generation and lipid peroxidation can also occur in mitochondria in the same manner as in microsome. Therefore, the observed actions of PQ in mitochondria suggest that mitochondria may also contribute to toxicity of this drug in vivo.

한국에서 신생아 집중치료 역사의 이정표

최중환 대한신생아학회 2013 Neonatal medicine Vol.20 No.3

Neonatal intensive care was introduced much later in Korea than in Europe and the United States, where it was introduced during the last decade of the 19th century. During the 1950s–60s, general supportive neonatal care could be provided in nurseries, and during the 1960s–70s, incubator care could be given to preterm infants in premature rooms. In the 1980s, neonatal intensive care could be provided to premature and sick full-term infants in neonatal intensive care units (NICUs)of some major medical centers; the quality of neonatal intensive care improved and the number of NICUs rapidly expanded during the 1990s and 2000s. It can be assumed that the rapid development of neonatal intensive care in Korea may have been induced by the improvement in the Korean socio-economical environment,public demand, numerous study visits and lectures in Korea by distinguished foreign neonatologists, return of native Korean neonatologists trained at famous foreign institutions, and establishment of Korean medical societies (e.g., the Korean Society of Perinatology and the Korean Society of Neonatology). As a result,neonatal and infant mortality rates have dramatically decreased in Korea, especially the mortality rates of low birth weight, very low birth weight, and extremely low birth weight infants. However, despite present and future difficulties in korea,it is essential to develop and promote the more advanced and institutionalized neonatal intensive care with the set-up of regionalization and transportation system at the perinatal centers in cooperation with primary and secondary hospitals, the government, city, and communities.

신생아 저산소성-허혈성 뇌병증

최중환 주식회사 녹십자 2002 녹십자의보 Vol.30 No.4

노니 뿌리 추출물의 pH 조건별 실크 염색성 고찰

최중환,홍엄지,최란,홍선표,고준석,Choi, Joong Hwan,Hong, Umji,Choi, Ran,Hong, Sunpyo,Koh, Joonseok 한국섬유공학회 2014 한국섬유공학회지 Vol.51 No.4

Morinda citrifolia, commercially known as Noni, is a tree that grows widely throughout the Pacific, and is recognized as one of the most significant sources of traditional medicines among Pacific Island societies. The bark and the roots of the tree contain red and yellow pigments respectively, which are both used in the manufacture of dyes. Dyes from Noni are being used traditionally, to color clothing and fabrics. In this study, dyeing properties of Noni root extracts on silk fabrics at various pH conditions were investigated.

INCONEL 718 초내열 합금의 열처리에 따른 미세조직 변화

최중환,이기룡,조창용,김인배 ( J . H . Choi,K . R . Lee,C . Y . Jo,I . B . Kim ) 한국열처리공학회 1992 熱處理工學會誌 Vol.5 No.2

Microstructural evolution of wrought Inconel 718 superalloy with different heat treatment conditions was studied. Heat treatment was performed via conventional(CHT), modified(MHT), Merrick(MeHT) and modified Merrick(MMeHT) methods. The size of γ` and γ precipitates which are principal strengthening phases in Inconel 718 superalloy increase in order of CHT, MHT, MeHT. For the case of MMeHT, a coexistence of fine γ` precipitate and very coarse particles due to exess growth of γ which is called bimodal distribution, was observed. CHT gave the finest grain size. (Ti, Nb)C carbide and needle-like δ phase were formed together at grain boundaries for CHT, and were formed both inside and at boundaries of grains for MHT, MeHT and MMeHT. Morphology of partially serrated grain boundaries was developed in all heat treatment conditions except CHT.

Storage Modulus of Polybutadiene Core in ABS Polymers with Different Degrees of Grafting

최중환,유종훈,김상용 한국고분자학회 2000 한국고분자학회 학술대회 연구논문 초록집 Vol.2000 No.4

1992년도 춘계 학술강연 및 발표대회 개요 - 가공 ( 발표 41 ) : Inconel 718 초내열 합금의 열처리에 따른 미세조직 변화

최중환,이기룡,조창용,김인배 대한금속재료학회 ( 구 대한금속학회 ) 1992 대한금속재료학회 학술대회 개요집 Vol.1992 No.1