(±)-Camphor가 ICR 마우스 수컷의 간 cytochrome P450 효소 활성에 미치는 영향

오은경,박형건,배기현,최옥진,최은경,최창근,한진희,정태천 한국환경독성학회 2002 환경독성보건학회지 Vol.17 No.4

Effects of (±)-camphor on liver cytochrome P450 enzymes were investigated in male ICR mice. Mice were treated intraperitoneally with 0, 200, 400 and 800 mg/kg of (±) -camphor in corn oil for 3 consecutive days. Twenty four hr after the final treatment, the animals were subjected to necropsy. The activities of serum aspartate aminotransferase and serum alanine aminotransferase were slightly changed by the treatment with (±)-camphor at the doses used. Administration o(±)-camphor to mice significantly induced the hepatic activities of pentoxyresorufin O-depentylase and benzyloxyresorufin O-debenzylase and weakly induced ethoxyresorufin O-deethylase in dose-dependent manners. The present results suggested that (±)-camphor might act as a relatively specific inducer of hepatic cytochrome P450 213 in male ICR mice.

표고 폐골목으로 제조한 목질보드의 성질

최용순,황원중,한태형,김남훈,권진헌 江原大學校 森林科學硏究所 1998 Journal of Forest Science Vol.14 No.-

要約표고폐골목의 재활용을 목적으로 폐골목과 정상재의 칩을 일정비율로 혼합하여 얻은 목질보드의 성질을 조사, 검토하였다. 그 결과 폐골목의 목섬유는 정상재보다 다소 짧고 표 면이 거칠었으며 폐골목 변재부의 밀도는 정상재에 비해 상당히 낮았다. 파티클보드의 두께 팽윤율 및 파괴계수의 시험결과 폐골목을 25~50% 정도 혼합한 경우는 정상재와 비슷한 값 을 나타냈다.결론적으로 폐골목은 파티클보드의 재료로 사용될 수 있고 정상재와의 혼합비율은 25~50% 범위에서 조정되어야 할 것으로 생각되었다.ABSTRACTTo provide further information for reutilization of the bed-logs decayed by oak mushroomfLentinus edodes), the properties of wood-based board prepared with mixed materials of normal wood and bed-logs were examined.Wood fibers in bed-logs showed different morphology from normal wood fibers, that is, shorter length and rough surface. Thickness swelling increased with increasing mixing ratio of bed-log. On the other hand, modulus of rupture(MOR) in bending strength decreased. In products, the visual surface of board prepared from higher mixing rate of bed-log chips was smooth.Consquently, it is considered that the optimum mixing rate of bed-log to normal wood is the range of 25-50% and the bed-log can be used for raw material of board instead of normal wood.

웨이브렛 변환을 이용한 초음파의 조직 특성화 연구

최민주,홍경진,박재우,이헌주 제주대학교 공과대학 첨단기술연구소 2001 尖端技術硏究所論文集 Vol.12 No.2

본 논문에서는 조직의 특성화 변수로 산란체의 간격에 대해 고려하였다. 조직 내에서 산란된 초음파 신호를 분석하여 특정 위치에서의 산란체의 간격을 추정하였다. Born approximation 이용하여 얻어진 초음파 반사 신호를 이용하여 모의 실험을 하였다. 산란체의 위치는 초음파 신호를 웨이브렛 변환 후 여러 단계에서 반복적으로 출현하는 높은 계수 값의 위치로부터 예측하였다. 시뮬레이션 결과 본 연구에서 개발된 알고리즘은 산란체의 간격이 초음파의 파장보다 큰 경우 정확하게 산란체의 간격을 추정하고 있음을 확인하였다. 산란체 간격 추정 알고리듬을 이용하여 조직내 산란 간격을 영상 변수로 한 초음파 영상을 구성하고 임상적 유용성을 고찰하였다.

체외 충격파 쇄석기에 의해 발생된 음향 흐름 현상 연구

최민주,이승환,홍경진,김호찬,박재우,이헌주 제주대학교 공과대학 첨단기술연구소 2001 尖端技術硏究所論文集 Vol.12 No.2

Acoustic streaming produced by an extracorporeal shock wave lithotripter was visualized for the first time in the present study. It was observed that the streaming velocity increased with the shock wave amplitude and was reaching up to 3 cm/s at the highest output setting of the lithotripter.

무선 환경에서 안전한 종단간 보안을 제공하는 AWTLS(Alternative Wireless Transport Layer Security) 프로토콜 : AWTLS(Alternative Wireless Transport Layer Security) Protocol

최진규,이헌길 강원대학교 정보통신연구소 2002 정보통신논문지 Vol.6 No.-

The WAP is a set of protocols that optimizes standard TCP/IP protocols, for use under the low bandwidth, high latency conditions often found in wireless networks. In WAP, WTLS(Wireless Transport Layer Security) is a subprotocol that it has been suggested for security communications. This protocol is a modified version of the TLS(Transport Layer Security) appropriate for wireless networks. In the data exchange between WTLS and TLS protocol, the message transmitted between the handset and the server is unencrypted for a very brief moment inside the WAP gateway. Even though the interval time the message remains unencrypted is very short, he or she who has an administrator account can attempt to view the unencrypted message. Therefore, in this paper, we propose the safe end-to-end security model, which is called AWTLS(Alternative Wireless Transport Layer Security). The proposed AWTLS can not only prevent the gateway from viewing the uncrypted message, but also reduce the encryption/decryption overhead of the mobile terminal.

고도보정 공간내삽에 의한 전국의 1km²단위 기상실황 추정

윤진일,이동석,최재연,조성인,박은우,황헌 한국농업정보과학회 1999 농업정보과학 Vol.1 No.1

Conventional method of generating meteorological surfaces over geographic areas often neglects the elevation effect which is considered to be a single most important control over local climate. Deviation of the estimates may exrled practical limits at some areas with complex toprlgraphy. A digital map featuring coordinates and elevation data of 72 weather stations in Korea were joined with hourly weather(trmperature, relative humidity, precipitation and wind speed) observations at the stations by using a geographic information system software. An inverse distanre weighted interpolation was done on the point features to generate prim-itive meteorological and elevation surface grids consisting of 430×600 cells, respectively. Elevation difference at each cell between the United States Geological Survey's 1 km digital elevation model and this virtual ele-vation surface was calculated. Known relationships between meteorological elements and the elevation differ-ence were used to derive "correction grids" representing the potential effects of elevation difference at each grid cell. The correction grids were added or multiplied to the primitive meteorological surfaces to obtain ele-vation-corrected estimates for corresponding elements. This srheme was applied to hourly data of 27 March 1998 to generate the elevation-corrected mrteorological surfaces. Observed data of 350 automated weather sta-tions were used to partially validate the accuracy of the results. This simple scheme sHelved a feasibility of a near-real time generation of hourly meteorological surfaces for temperature and rainfall with an affordable error range.

지역사회 획득 급성 신우신장염 여성환자에서 검출된 원인균의 항균제 감수성 및 항균제의 사용

위성헌,최수미,이동건,김수영,김상일,유진홍,신완식,강문원 대한감염학회 2002 감염 Vol.34 No.6

Staphylococcus aureus와 Coagulase-Negative Staphylococcus Species에 대한 Arbekacin의 시험관내 항균력

위성헌,강진한,허동호,이동건,김상일,김양리,최정현,김종현,유진흥,허재균,신완식,강문원 대한감염학회 2001 감염 Vol.33 No.4

Background : Most strains of methicillin-resistant Staphylococcus aureus (MRSA) now exhibit high-level resistance to various antibiotics, such as β -lactam antibiotics, aminoglycosides, macrolides, tetracyclines and quinolones. Recent reports describing the therapeutic failure of vancomycin for MRSA infections have arisen considerable concerns regarding the emergence of MRSA strains, which will require new therapeutic agents. Arbekacin, an aminoglycoside antibiotic, has antibacterial activity against both gram-positive and gram-negative bacteria and is stable in the presence of aminoglycoside inactivating enzymes produced by S. aureus. In this study, we compared the antibacterial activity of arbekacin with those of vancomycin, gentamicin, and amikacin against Staphylococcus aureus (S. aureus) and coagulase-negative staphylococci (CNS). Methods : For a collection of 549 S. aureus and 251 CNS isolates from three Catholic University Hospitals in Korea, minimum inhibitory concentrations (MICs) of arbekacin, vancomycin, amikacin and gentamicin were determined by agar dilution method using Mueller-Hinton agar according to NCCLS (National Committee for Clinical Laboratory Standards, USA)criteria. Results : Among 549 S. aureus isolates, 278 isolates were MRSA and 271 isolates were methicil sensitive S. aureus (MSSA). MIC50 & MIC90 of arbekacin against 549 S. aureus were 0.5 & 1 ㎍/mL, and MIC50 & MIC90 of vancomycin were 1 & 1 ㎍/mL. MIC of arbekacin against 549 S. aureus isolates ranges from 0.03 to 4 ㎍/mL, and MIC of vancomycin against 549 S. aureus ranges from 0.25 to 2 ㎍/mL. MIC90 of amikacin against 549 S. aureus was 32㎍/mL, and that of gentamicin was 128 ㎍/mL. MICs of amikacin and gentamicin were variable, ranging from 0.125 to 256, and otherwise arbekacin and vancomycin revealed relatively narrow range of MICs. MIC90 of arbekacin against 278 MRSA isolates & 271 MSSA were 1 & 0.5 ㎍/mL, and those of vancomycin against MRSA & MSSA were 1 & 1 ㎍/mL. MIC90 of amikacin against 278 MRSA & 271 MSSA isolates were 32 & 4 ㎍/mL, and that of gentamicin against MRSA & MSSA isolates were 128 & 32 ㎍/mL respectively. Among 251 CNS isolates, 122 isolates were MRCNS and 129 were MSCNS. MICSO & MIC90 of arbekacin against 251 CNS isolates were 0.25 & 2 ㎍/mL, and those of vancomycin were 1 & 2 ㎍/mL. MIC of arbekacin against 251 CNS isolates ranges from 0.015 to 32 ㎍/mL, and that of vancomycin isolates ranges from 0.25 to 2 ㎍/mL, MIC90 of arbekacin against 122 MRCNS & 129 MSCNS isolates were 2&0.3 ㎍/ML, and those of vancomycin were 2&s ㎍/ML. MIC90 of amikacin against 251 CNS isolates was 32 ㎍/ML, and that of gentamicin was 128 ㎍/ML for CNS. MIC90 of amikacin against 122 MRCNS & 129 MSCNS isolates were 128 & 8㎍/mL, and those of gentamicin ere 256 & 32 ㎍/mL. Conclusion : Considering above results, arbekacin can be useful agent against most strains of MRSA and MRCMS, which exhibit high-level resistance to amikacin and gentamicin. (Korea J Infect Dis 33:254~260, 2001)

아고용한 Zr-Nb 2원계 합금의 미세조직 및 부식특성

林潤洙,崔洋鎭,河憲永,魏明鏞 大田産業大學校 2000 한밭대학교 논문집 Vol.17 No.1

Effect of niobium content on the microstructure and corrosion characteristic of hypo-solubility in binary Zr-Nb alloys were studied. The specimens with 0.2 and 0.4wt.% of niobium were prepared under various annealing temperatures from 400℃ to 800℃ and times from 30 to 5.000 minutes after vacuum arc remelting. The microstructures behavior was observed by a polarized optical microscope. TEM and micro-vickers hardness tester. The recrystallization temperature of the alloys slightly increased with niobium content due to increase of activation energy. The grain growth of the alloys more 0.2 than 0.4 wt.% of niobium occured rapidly. The specimens for corrosion test were prepared by annealing with 590℃ for 2hr to be recrystallized and performed in distilled water at 360℃ using a static mini-autoclave and the corrosion characteristic was measured by weight gains with exposure time. With increasing Nb content from 0.2 to 0.4wt.% the corrosion resistance in Zr-xNb binary alloys decreased an d oxide structure was slowly transformed from tetragonal -ZrO2 to monoclinic-ZrO2.

박육구상흑연주철 FCD600 제조에 관한 연구

柳民,崔洋鎭,河憲永 한밭대학교 산업과학기술연구소 2001 논문집 Vol.5 No.-

This study was to investigate the manufacturing of FCD 600 grade with Bi and RE added in strength cast iron. The specimen were designed and manufactured into the Bar and grade shape and the shrinkage cavity were composed of Fe-3.4%C-0.4%Mn-2.7%Si-0.02%S-0.01%Bi - x RE (x = 0.002, 0.004, 0.008, 0.012, 0.016, 0.02, 0.03, wt.%). Tensile strength, hardness behaviors were measured by using UTM, Brinell Hardness Tester. Micro-structures were investigated by Optical Microscope and SEM. The results obtained from contraction testing are as follows. The chill depth was the lowest within 0.016% Ce content and the chill depth was invariable within 0.016∼0.02% Ce content. Tensile strength was also obtained the highest value of FCD 600 in 0.016% Ce content. Hardness value was more higher in com-addition of 0.016% Ce than in sole addition of Bi. After testing structure, spheroidal rate was superior in 0.016% Ce content. Spheroidal rate and Spheroidal graphite nodular were the highest increasing value in 0.016% Ce content. Spheroidal graphite nodular count was also increased in same content and was higher value than in sole addition of Bi. Spheroidal rate and spheroidal graphite nodular count could trend toward high value from 0.016% to 0.02% Ce content. As a result of testing, thin wall spheroidal graphite cast iron of FCD 600 grade was obtained from the specimen manufactured by com-addition of 0.01%Bi and 0.016 % Ce.