시판되고 있는 까칠복 ( Fugu stictonotus ) 의 독성

김경찬,박진우,이명자,김상록,김동수,김현대,박영호 ( Kyung Chan Kim,Jin Woo Park,Myung Ja Lee,Sang Rok Kim,Dong Soo Kim,Hyun Dae Kim,Yeung Ho Park ) 한국수산과학회 1995 한국수산과학회지 Vol.28 No.1

Ten specimens (5 males and 5 females) of the pufferfish, Fugu stictonotus ($quot;Ggachilbog$quot;), were collected at a fish market of Pusan, Korea in july 1993, and examined for anatomical distribution of toxicity by mouse assay method. The frequency of toxic specimens was 40% for liver, 60% for ovary, 40% for skin and 60% for bile in female puffers. The highest toxicities were 107, 107, 29 and 93MU/g for liver, ovary, skin and bile, respectively; and average toxicity ±S.E, values were 14±11, 48±22, 4 ±3 and 12±9MU/g, respectively. The range of total toxicity was shown to be from 0 to 35,316MU. The characteristic pattern of toxin distribution observed on these specimens was exhibited; both muscle and testis were non-toxic, but others were weakly toxic. Also, there was significant difference for toxicity between male and female specimens.

HL-60 세포에서 $TNF-{\alpha}$에 의한 MCP-1 발현에 미치는 Betulinic Acid의 효과

김경찬,이추희,Kim, Kyung-Chan,Lee, Chu-Hee 대한약학회 2008 약학회지 Vol.52 No.1

Betulinic acid, a naturally occurring pentacyclic triterpenoid, is found in abundance in the outer bark of white birch (Betula alba). In this study, we investigated if betulinic acid affects cytokine expression from activated macrophage cells. ELISA result showed that stimulation of HL-60 cells with proinflammatory cytokine such as $TNF-{\alpha}$ resulted in MCP-1 release into culture medium. In addition, transcriptional upregulation of MCP-1 in response to $TNF-{\alpha}$ was observed by RT-PCR analysis. However, incubation of HL-60 cells with betulinic acid prior to $TNF-{\alpha}$ treatment abrogated MCP-1 expression in transcription and translational level. Consistent with a number of studies which reported requirement of ERK activation for $TNF-{\alpha}$ expression, Western blot analysis showed that $TNF-{\alpha}-induced$ ERK activation was suppressed by pretreatment of HL-60 cells with betulinic acid. Taken together, our data indicate that betulinic acid exerts its anti-inflammatory effect through inhibition of $TNF-{\alpha}-induced$ ERK activation which is required for the subsequent MCP-1 release.

BF₃LiMA를 단량체로 하는 고체 고분자전해질 합성과 전기화학적 특성

김경찬,류상욱,Kim, Kyung-Chan,Ryu, Sang-Woog 한국전기화학회 2011 한국전기화학회지 Vol.14 No.4

합성된 $BF_3LiMA$ 리튬염을 단량체로 사용하는 고체 고분자전해질을 제조하고 $BF_3LiMA$의 농도가 이온전도도에 미치는 영향 및 전기화학적 안정성을 교류임피던스 측정법과 선형전위주사법을 통하여 평가하였다. 그 결과 $BF_3LiMA$가 12.9 wt%인 고체 고분자전해질에서 $7.71{\times}10^{-6}S\;cm^{-1}$의 가장 높은 $25^{\circ}C$ 이온전도도가 관찰되었으며 이 값을 전후로 이온전도도는 다소 감소하는 경향이 나타났다. 이러한 결과는 저농도의 $BF_3LiMA$에서 발생할 수 있는 리튬염의 부족과 고농도의 $BF_3LiMA$에서는 발생할 수 있는 고분자기질의 유동성 감소가 원인으로 해석된다. 또한 $BF_3LiMA$ 기반의 고체 고분자전해질은 음이온이 고정되어 있는 자기-도핑형 계열로서 $60^{\circ}C$에서 6.0 V까지 우수한 전기화학적 안정성을 보여주었다. Solid polymer electrolytes using $BF_3LiMA$ as monomer were synthesized by usual one step radical polymerization in THF solvent. The effect of $BF_3LiMA$ concentration on ionic conductivity and electrochemical stability was investigated by AC impedance measurement and linear sweep voltammetry. As a result, the highest ionic conductivity reached $7.71{\times}10^{-6}S\;cm^{-1}$ at $25^{\circ}C$ was obtained in 12.9 wt% of $BF_3LiMA$ content. Further increase or decrease of $BF_3LiMA$ content result to decrease the ionic conductivity due to the brittle matrix properties in former case and the insufficient number of charge carrier in the latter case. Furthermore, since the counter-anion was immobilized in the self-doped solid polymer electrolytes, high electrochemical stability up to 6.0 V was observed even in $60^{\circ}C$.

초정밀작업을 위한 6자유도 마이크로 스테이지의 개발

김경찬,김수현,곽윤근,Kim, Kyung-Chan,Kim, Soo-Hyun,Kwak, Yoon-Keun 대한기계학회 1998 大韓機械學會論文集A Vol.22 No.2

A new 6 degrees-of-freedom micro stage, based on parallel mechanisms and actuated by using piezoelectric elements, has been developed for the application of micro positioning such as semiconductor manufacturing devices, high precision optical measurement systems, and high accurate machining. The micro stage structure consists of a base platform and an upper platform(stage). The base platform can effectively generates planar motion with yaw motion, while the stage can do vertical motion with roll and pitch motions with respect to the base platform. This separated structure has an advantage of less interference among actuators. The forward and inverse kinematics of the micro stage are discussed. Also, through linearization of kinematic equations about an operating point on the assumption that the configuration of the micro stage remains essentially constant throughout a workspace is performed. To maximize the workspace of the stage relative to fixed frame, an optimal design procedure of geometric parameter is shown. Hardware description and a prototype are presented. The prototype is about 150mm in height and its base platform is approximately 94mm in diameter. The workspace of the prototype is obtained by computer simulation. Kinematic calibration procedure of the micro stage and its results are presented.

농업생산기반정비사업 계획설계기준 배수편 개정

김경찬,김영화,송재도,정상옥,Kim, Kyoung Chan,Kim, Younghwa,Song, Jaedo,Chung, Sangok 한국관개배수위원회 2014 한국관개배수논문집 Vol.21 No.1

In Korea, global warming caused by the climate changes impacted on weather system with increase in frequency and intensity of precipitation, and the rainfall pattern changes significantly by regional groups. Furthermore, it is expected that the regional and annual fluctuation ranges of the rainfall in the future would be more severe. Nowadays, agricultural drainage system designed by the existing standard of 20-year return period and 2 days of fixation time cannot deal with the increment rainfall such as localized heavy rain and local torrential rainfalls. Therefore, it is required to reinforce the standard of the drainage system in order to reduce the agricultural flood damage brought by unusual weather. In addition, it is needed to improve the standard of agricultural drainage design in order to cultivate farm products in paddy fields as facility vegetable cultivation and up-land field crop have been damaged by the moisture injury and flooding. In order to prepare for the changes of rainfall pattern due to climate changes and improve the agricultural drainage design standards by the increase of cultivating farm products, the purpose of this study is to examine the impact of climate changes, the changes of relative design standard, and the analytic situation of agricultural flood damages, to consider the drainage design standard revision, and finally to prepare for enhanced agricultural drainage design standards.

리뷰 - "뉴질랜드 방재계획제도 및 조직"

김경찬,Kim, Gyeong-Chan 한국방재협회 2012 방재저널 Vol.14 No.4

Pyrazolyl-1,4-benzothiazine 유도체의 합성

김경찬,김호식,Kim, Gyeong Chan,Kim, Ho Sik 대한화학회 2002 대한화학회지 Vol.46 No.6

자기-도핑형 poly(PEGMA-co-BF₃LiMA) 전해질의 합성과 이온전도도에 대한 PEGMA분자량의 영향

김경찬,류상욱,Kim, Kyung-Chan,Ryu, Sang-Woog 한국전기화학회 2012 한국전기화학회지 Vol.15 No.4

분자량이 각각 300(PEGMA300) 및 1100(PEGMA1100) g $mol^{-1}$인 PEGMA와 합성된 $BF_3LiMA$ 리튬염을 이용하여 다양한 조성의 고분자전해질을 제조하고 전기화학적 특성을 평가하였다. 흥미롭게도 AC-impedance 측정법에 의한 상온 이온전도도는 분자량 $300g\;mol^{-1}$로 합성된 액체 고분자전해질에서 $8.54{\times}10^{-7}S\;cm^{-1}$의 값이 얻어진 반면, PEGMA1100으로 합성된 고체상태의 고분자전해질에서 최대 14배 이상 높은 $1.22{\times}10^{-5}S\;cm^{-1}$가 관찰되었다. 이러한 결과는 PEGMA에 ethylene oxide 단위가 5개인 $300g\;mol^{-1}$보다 23개인 $1100g\;mol^{-1}$에서 리튬이온의 배위가 쉽게 일어나기 때문으로 해석된다. 또한 양이온 수율 측정결과 리튬메탈과 $BF_3$간의 반응으로 인해 0.6의 비교적 낮은 값이 나왔지만 초기 3000초 동안에는 0.9 이상의 값이 관찰되어 단일이온 전도체의 특징을 보여주었다. Polymer electrolytes consisted of $BF_3LiMA$ and 300 (PEGMA300) or 1100 (PEGMA1100) g $mol^{-1}$ of PEGMA were prepared and the electrochemical properties were characterized. Interestingly, the AC-impedance measurement shows $1.22{\times}10^{-5}S\;cm^{-1}$ of room temperature ionic conductivity from PEGMA1100 based solid polymer electrolytes while $8.54{\times}10^{-7}S\;cm^{-1}$ was observed in PEGMA300 based liquid polymer electrolytes. The more suitable coordination between lithium ion and ethylene oxide (EO) unit might be the reason of higher ionic conductivity which can be possible in PEGMA1100 based electrolytes since it has 23 EO units in monomer. The lithium ion transference number was found to be 0.6 due to the side reactions between $BF_3$ and lithium metal expecially for longer time but 0.9 was observed within 3000 seconds of measuring time which is strong evidence of a single-ion conductor.

아웃리거구조시스템과 메가구조시스템 적용에 따른 철근콘크리트 초고층 건물에 대한 부등축소의 영향

김경찬,김재요,Kim, Gyeong-Chan,Kim, Jae-Yo 한국전산구조공학회 2022 전산구조공학 Vol.35 No.1

초고층 건물에서 수평변위 제어와 수직부재에서 발생하는 부등축소에 대한 검토가 필수적이다. 수평변위 제어를 위해 근래에 아웃리거 구조시스템과 메가 구조시스템을 횡력저항시스템으로 사용한 초고층 건물이 증가하고 있다. 또한, 부등축소로 인한 구조적 문제를 해결하기 위해 부등축소량 예측과 예측결과를 통한 시공단계에서의 보정방법이 연구되어 왔으나 부등축소에 대한 횡력저항시스템의 영향 비교는 드문 편이다. 따라서, 본 논문에서는 수평변위 제어를 위해 아웃리거 구조시스템과 메가 구조시스템을 사용한 60층 규모의 철근콘크리트 주거용 초고층 건물에 대해 시공단계해석을 통한 부등축소를 비교하고 그 영향을 분석하고자 한다. 또한, 부등축소는 비구조요소의 파손 및 구조요소에 부가하중을 유발하기도 하며 부등축소가 야기한 문제는 초고층 건물에서 중요한 부재를 손상시킬 수 있으므로 각 횡력저항시스템별로 수직부재의 부등축소에 대한 영향을 분석하였다. It is essential to control the lateral displacement and differential axial shortening of the vertical elements in high-rise buildings. Recently, an outrigger or a mega structure system has been adopted to control the lateral displacement. Furthermore, to resolve the problems caused by differential axial shortening in high-rise buildings, analytical prediction and correction is often studied; however, the study on the comparisons of the lateral load resisting systems to address differential axial shortening is less. Therefore, in this paper, a 60-story RC residential building using an outrigger or a mega structure system is analyzed with a construction sequence. Moreover, differential axial shortening can result in an additional member force of structural members and failure of non-structural members. These problems caused by differential axial shortening affects the behaviors and can damage the important structure member in the high-rise buildings. Hence, the effects of the systems on differential axial shortening between the vertical elements in high-rise buildings are studied.

Churg-Strauss 증후군에 동반된 Wells` Syndrome

김경찬 ( Kyung Chan Kim ),정현 ( Hyun Chung ),박준수 ( Joon Soo Park ),박재복 ( Jae Bok Park ),최정윤 ( Jung Yoon Choe ),박성훈 ( Sung Hoon Park ),김지영 ( Ji Young Kim ),김성규 ( Seong Kyu Kim ) 대한류마티스학회 2008 대한류마티스학회지 Vol.15 No.1

Wells` syndrome is an inflammatory dermatosis with associated aberrant eosinophil responses caused by unknown factors. Its histology is characterized by erythematous plaques with flame figures in the dermis, which is potentially diagnostic but not pathognomic. Cases of Wells` syndrome in patients with Churg-Strauss syndrome (CSS), which is characterized by antineutrophil cytoplasmic antibody-related necrotizing vasculitis, marked peripheral eosinophilia, and eosinophil tissue infiltrates, have rarely been reported, and the pathogenic association between these two diseases remains undetermined. Differences of clinical and histopathologic features of these two diseases suggest that they are distinct disease entities, even though, in part, they share pathogenic mechanisms. Here we present a new case with Wells` syndrome in a patient with CSS, treated with systemic steroid.