Zn-Fe 합금 도금강판의 점용접성에 관한 연구

민준기,신재경,안효영,서수정,서창제 成均館大學校 科學技術硏究所 1992 論文集 Vol.43 No.1

Spot welding is widely used in automobile assembly lines. Electroplating of Zn-Fe on steel sheets is increasingly used in assembly lines, because of its good spot weldability, formability and corrosion resistance. In this study, to evaluate spot weldability, tensile shear strength and cross tensile strength of steel sheets electroplated with Zn and Fe up to 0.7mm thickness were investigated, and these mechanical properties were compared with those of steel sheets electroplated with Zn only. The thickness of electroplated steel sheets was measured with SEM. The following conclusions were obtained. (1) In spot welding, the weldability lobe was getting wider and directed toward low currency direction, in steel sheets electroplated with Zn-Fe compared with those electroplated with Zn only. (2) Electrode force and welding time obviously affected the ultimate welding strength, and the range representing constant ultimate welding strength was observed. (3) When Zn-Fe were electroplated on steel sheets, the ductility ratio was increased in optimal welding condition, indicating that good weldability was obtained. (4) Around 8.5KA where optimal strength existed, by spot welding, the amount of the electroplated layer was observed to be reduced by approximately 15% in thickness.

토끼에서 enrofloxacin과 enrofloxacin acetate의 比較藥物動態學

윤효인,박승춘,김창식,김민규,최기섭,신광순,박종일,조준형,조명행 충남대학교 수의과대학 동물의과학연구소 1996 動物醫科學硏究誌 Vol.4 No.-

This study was designed to examine the in vitro antibacterial activities and pharmacokinetics of enrofloxacin acetate (ENFXA) and enrofloxacin (ENFX). Two enrofloxacins had wide spectrum antibacterial activities against Gram positive and negative bacteria, and mycoplasma, showing potent antibacterial activities with low MICs (0.05-3.33 ㎍/㎖ for Gram positives, 0.002 ㎍/㎖ for Gram negatives and 0.02 ㎍/㎖ for mycoplasma). In order to investigate the profiles of two formulations of enrofloxacin we studied comparative pharmacokinetics of them in rabbits. Five rabbits were given 5 ㎎/㎏ body weight of each enrofloxacin formulation intravenously (i.v.) and orally (p.o.) in a cross-over study. Pharmacokinetic parameters of both formulations were calculated by the use of PCNONLIN, a computer program. Their bioavailibility in rabbits, the means of the area under the curve (AUC). After oral administration of each formulation in rabbits, the mean elimination half-lives (t_1/2,ke) were 3.25h (ENFX) and 4.32 h (ENFXA), and mean AUC 4.27 ㎍·h/㎖ (ENFX) and 6.21 ㎍·h/㎖ (ENFXA). Both enrofloxacin formulations seemed to have good tissue distribution and penetration as indicated by large volume of distribution: 4.76 1/㎏ for ENFX and 7.23 1/㎏ for ENFXA. With the results obtained in this study, ENFXA could be used in place of ENFX in rabbits.

SiO₂첨가물질이 SnO₂계 가스 센서의 안정성에 미치는 영향

박광묵,민봉기,최순돈,남효덕 경북대학교 센서기술연구소 2002 센서技術學術大會論文集 Vol.13 No.1

그레이브스병에서 방사성 요오드 치료에 따른 갑상선 자극 호르몬 수용체 결합억제 면역글로불린(Thyrotropin Binding Inhibitory Immunoglobulin, TBII)의 변화

조영석,권기현,이준철,나소영,이효진,홍우정,이유선,김군순,송민호,김영건,노흥규 충남대학교 의학연구소 2003 충남의대잡지 Vol.30 No.2

Prediction of thrapeutic response to radioiodine in Graves' disease is poorly understood. Although thyrotropin binding inhibitor immunoglobulin(TBII) level is a strong index for relapse after antithyroid drug medication, conflicting results are reported regarding its prognostic significance in Graves' disease treated with RAI. This study is dengned to evaluate possible relationship between post-treatment hypothyroidism and TBII in Graves' disease treated with RAI. Fourty two patient with Graves' disease after radioiodine treatment were studied retrospectively. The subject were divided into hypothyroid group and euthyroid or hyperthyroid group. We evaluated the association of hypothyroidism and TBII with radioiodine treatment dose. The mean age of hypothyroid group was 48±11 years and euthyroid or hyperthyroid group was 47±12 years. There was no difference in two groups. And there was no significant difference in post- treatment TBII between two groups(49.9±28.5%, 29.9±14.3%, p-value >0.05). The treatment-dose had no influence on post-treatment thyroid state. Euthyroid or hyperthyroid group was done with 13.6±6.9mCi and hypothyroid group was 17.0±10.4mCi(p-value > 0.05). TBII had no prognostic significance on long-term hypothyrodism in Graves' disease treated with radioiodine. And, treatment-dose had no influence on post-treatment thyroid state.

자가혈당측정기 Precision Q.I.D 평가

이수연,이성규,김종원,민원기,박효순 대한임상병리학회 1999 대한임상병리학회지 Vol.19 No.4

간경변증 환자에서 Escherichia coli 균혈증 합병 시 간기능 장애에 따른 C-reactive protein 생성 능력에의 영향

박완범,강철인,김동민,이기덕,장희창,김홍빈,오명돈,이효석,최강원 대한감염학회 2003 감염과 화학요법 Vol.35 No.5

목적 : C-reactive protein(CRP)은 간에서 생성되는 급성 반응물질이다. 하지만 간부전증 환자에서 CRP의 반응이 간기능에 따라 어느 정도 영향을 받는지는 별로 알려진 바가 없다. 본 연구에서는 간기능에 따른 CRP 생성 능력을 평가하고자 하였다. 방법 : E. coli 균혈증이 있는 간경변증 환자 30명을 대상으로 하였고 간기능은 균혈증이 발생하기 전 2개월 이내에 측정된 혈청 빌리루빈, 혈청 알부민, 프로트롬빈시간, Child-Pugh 점수로 평가하였다. 대조군 A는 간질환이 없으면서 E. coli 균혈증이 발생한 환자 30명으로 하였고 대조군 B는 간경변증이 있으면서 급성 감염의 증거가 없는 환자 30명으로 하였다. 환자군과 대조군 간에 CRP의 최대값을 비교하였다. 결과 : CRP의 최대값은 환자군에서 7.3±5.0㎎/dL, 대조군 A에서 17.9±8.3㎎/dL로 환자군에서 유의하게 낮았다.(P<0.001). 간경변증 환자에서 CRP의 생성은 Child-Pugh 점수에 비례하여 감소하였으나(P=0.004) Child=Pugh class C의 간기능을 가진 환자군에서도 대조군 B와 비교하여 의미있는 CRP의 생성을 보였다(5.3±3.2 vs. 0.5±0.4㎎/dL, P<0.001). 결론 : 간기능부전 환자에서 CRP 반응은 간기능 저하 정도에 따라 둔화되지만 심한 간기능 장애를 가진 환자에서도 CRP의 생성은 유지된다. Background : C-reactive protein (CRP) is an acute phase reactant produced in the liver. To assess the influence of liver dysfunction on the production of CRP, we evaluated CRP response to E. coli bacteremia in patients with or without liver cirrhosis (LC). Methods : 30 LC patients who developed spontaneous peritonitis with E. coli bacteremia were enrolled in the study. Baseline values of total bilirubin, serum albumin, and prothrombin time were obtained within 2 months prior to infection. Liver dysfunction was categorized according to the Child-Pugh score. 30 patients with E. coli bacteremia who had no underlying liver dysfunction were included as a control group. Matched-control of 30 LC patients without evidence of acute infection was also included. The peak CRP values were compared among the groups. Results : In the patients with E. coli bacteremia, the mean value of peak CRP was 7.3 (+/- 5.0) ㎎/dL in LC patients, 17.9 (+/- 8.3) mg/dL in patients without liver dysfunction (p<0.001). In the advanced LC patients with Child-Pugh class C, the level of CRP was 5.2 (+/- 3.3) ㎎/dL in patients with E. coli bacteremia, 0.5 (+/- 0.4) ㎎/dL in patients without acute infection (P<0.001). Child-Pugh score had correlation with decrease of CRP (linear regression test, P=0.004). Conclusion : CRP response during E. coli bacteremia was attenuated but maintained even in patients with advanced liver dysfunction.

오차드그래스(Dactylis glomerata L.)의 품종에 따른 종자유래의 캘러스 형성률과, 캘러스 크기 및 식물체 재분화 효율의 비교

배은경,이인애,김기용,이병현,손대영,이효신,정민섭,조진기 Plant molecular biology and biotechnology research 2002 Plant molecular biology and biotechnology research Vol.2002 No.-

Comparison results of callus formation ratio from seed explants, callus sizes, regeneration ratios from callus and regeneration efficiency [calculated by following formular; callus formation ratio(%) × regeneration ratio(%)/100]for 27 ochardgrass (Dactylis glomerata L.)varieties imported and Hapsung 2 developed in Korea are as follows; 1. Among ochardgrass varieties showing more than 50% callus formation ratios, the descending order of callus formation ratio after bedding the seed explants for 4 weeks was 93>Sparta>Pizza>Condor>Lidaglo>Glorus>Hapsung2>Frode. 2. The callus sizes after bedding for 4 weeks were in the range of φ 0.43cm~4.2cm in which there was 10 times size difference between the largest one and the smallest one but most of them were between φ2.5cm~4cm. 3. The regeneration ratio from callus among varieties were in the range of 0~36% and descending order of the upper 6 varieties was Plano>Akimidori>Justus>Lidacta>Currie>Hall mark. 4. The regeneration efficiency which is calculated by the ratios of regeneration from seed explant numbers was between 0 to 17.4% among which Justus showed the highest value in the 4-week treatment. 5. The correlation between callus formation ratios and the callus sizes, callus formation ratios and regeneration efficiency, and callus sizes and regeneration efficiency were r=0.5765, r=0.6365 and r=0.6246, respectively in 4-week callus and all the correlations were significant on the 1% level. 6. In 6-week callus, the descending order callus formation ratios from seed sxplants for the best 6 varieties was Condor>Sparta>93M>Justus>Potomac>Lidaglo>Frode. 7. The callus sizes formed were between φ1.5~5.7cm in which Sparta, the largest one of φ5.7cm was five times larger than the smallest one. The callus size of the control variety. Hapsung 2 was φ3.8cm, which belonged to larger size. 8. Regeneration ratio showed a great deviation among varieties from 6-week old calli by showing from 0% to 100% in which all the calli were regenerated in Plano while no callus was regenerated in Juno, 9. The range of regeneration effciency was between 0~28% among varieties in which the values from 6-week callus treatment were larger than those from 4-week callus treatment. Especially, the value of Potomac in 6-week was 3 times larger than that in 4-week. 10. The correlation between callus formation ratios and the callus sizes, callus formation ratios and regeneration efficiency, and callus sizes and regeneration effciency were r=0.8369, r=0.6683 and r=0.5937, respectively in 6-week callus, and all the correlations were significant on the 1% level.

식품중 중금속 규격 과학화를 위한 조사연구(Ⅲ) : 음료수의 중금속 향량에 대하여 Heavy metal contents beverages

김명철,김미혜,권기성,정소영,박성국,이윤동,이승훈,김은정,강민철,박효정 식품의약품안전청 2001 식품의약품안전청 연보 Vol.5 No.-

본 연구는 국내에 유통되고 있는 음료류중 중금속 함량을 파악하여 식품공전 제 ·개정시 과학적 기초자료로 활용하고자 수행하였다. 출 2☞7여건의 음료류에 대하여 유도결합플라스마 분광기(ICP), 원자홉광광도 계(AAS) 및 수은분석기 등을 치용하여 납, 카드윰 등 중금속함량을 측정하였으며 그 결과는 다음과 같다 [단위 : min-ma)t(irran) ; mrk3 ; f : 0.0001-0.0025(0.0003), As :불검출곰.OB45(0.0003), Pb : 불검출-0.0893(0.0041),Cd ' 불검출곤.0064(0.0011), Cfl : 불검출.(i9(0.05), Mn : 불검출글.찌(0.16), Zn : 불검출-12.85(0.뽀), Sn :불검출-45.36(1.97). 본 조사결과 우리나라에서 유통되고 있는 음료류 중 납 등 중금속 함량은 외국의 모니터랑 결과와 유사하였다. 또한 우리나라 국민이 음료류를 통한 중금속 섭취량은 FAO/UTfO에서 설정한 잠 정주간섭취처용량의 약 0.OleO.06% 이하로 매우 낮았다. 편 연구조사에서 먼어진 결과는 음료류 중 납 기준 설정을 위한 중요한 기초자료로 활용할 수 있는 것으로 사료된다. This study was conducted to estimate the cantents of heavy netals in beverages and to fIFovide a scientific basis for heav)· meta3 standardizatior of Korea Food Code. The contents of rriercur17(Hg), lead(Pb), cadmium(Cd), arsenic(As), manganese(Mn),ziac(Zn), tin(Sn) and topper(Cu) were determined in a total of 20? samples of beverages usinga mercury anal!'zer, aromic absorption spectrophotometer(AAS) and inductiuety coupled plasmaspectrometer(fcpl. The vatues of heavy metals In beverages were as fellows (min-max (mean) , mg/krl , Hg : 0.DOOI-0.0095(0.0004), As : ND-0.0245(0.0003), Pb ND-0.0893(0.0041), Cd : ND-0.0064(0.0011),Cu : ND-1.69(0.03), Mn : ND-3.94(0.16), Zn ND-12.85(0.28), Sn : ND-45.36(1,97). Our results weresimilar to thofe reported by other countries. It is thought that our results could be utilizedimportant references toT es?ablish the standard of lead in beverages.

간경변증 환자에서 Escherichia colli 균혈증 합병 시 간기능 장애에 따른 C-reactive protein 생성 능력에의 영향

박완범,강철인,김동민,이기덕,장희창,김흥빈,오명돈,이효석,최강원 대한감염학회 2003 감염과 화학요법 Vol.35 No.5

Betulinic acid 등의 세포독성 조절 연구

염영나,조현영,김현석,황명실,윤은경,이효민,김승희,양지선,양기화 식품의약품안전청 2001 식품의약품안전청 연보 Vol.5 No.-

과일이나 식물체 등애 천연적으로 존재하면서 돌연변이억제나 항산화효과 등, 암이나 성인병 등에 대한 예방효과를 보이는 것으로 알려진 phytocherilical을 중심으로 aminopept건ase 활성 억제 능력을 조사하여 암전툴과정과 혈관신생과정에서 발된이 증가하는 것으로 알려진 arnjnoepeptidase N APh억제제를 스크리닝하고 암전이 예방이나 암치료에 활용하고자 본 연구를 수행하게 되었다 Leucine andnopeptidase에 대한 식물유래성분(betulinic acid, curcvmin, indomethacin, ellagic acid quercetin, nocodazole, urso:ic acid, resveratrol, h)'pericin, caffeic acid)의 찰성억제능력을 조사하여 그중 촬성억제능력이 탁월한 curcundn, indomethacin, betulinlc 3c펀의 APN enzyme netics를 수헝 하였다. Curcumin의 andnopeptidase 띠 활성을 억제하는 농도와 혈관신생의 억제 농도가 일치하고 APN 단클론항체 처리한 HT1080 세포의 유세포측정결과 curcumin·라 APN 단클론항체가 경정적으로 APN예 결합됨을 확인함에 따라 curcumin이 암전이를 억제하는 기전이 APN 억제에 기인한 것으로 추정되는 결과이다. 한편 Betulinic ac,김는 APN 활성에는 영향을 미치지 못하고, 미토콘드리아의 막전 위를 떤화시키고 caspase근 활성을 증가시켜 apoptosis를 유발하였다. 포한 betulinic acid로 tlibe formation assay와 」'n ufuo CAM assay를 수행한 결과 혈관신생과정을 억제하는 것이 확인되었다 따라저 Betulinic 3fid와 curcumin은 서로 작용기전은 다르지만, 암전이 떼방이나 암치료에 활용가치가 높은 약물로 인식되었다. This study is to evaluate phytochemicals that have inhibitory activity on aminopeptidase N (APN) which is transmembrane metalloprotease to play functional role in matrix degradation and invasion by tumor cells. At first, we did screening of APN inhibitors among the phytochemicals with chemopreventive effect including betulinic acid, curcumin, indomethacin, ellagic acid, quercetin, nocadazole, ursolic acid, reveratrol, hypericin, and caffeic acid etc. by the fluorometric assay using L-alanine 4-methylcoumaryl-7-amide(Ala-AMC) as a substrate. Curcumin has inhibitory effect on APN activity as well as angiogenesis in a same condition(IC_(50) value=about 10μM). Curcumin on APN activity works as a noncompeptitive ingibitor. FCM analysis shows the competitive binding of curcumin and monoclonal antibody of APN to HT1080 cell. This results means that curcumin blocks the angiogenesis by the mechanism of APN inhibition. Betulinic acid which is working as a inhibitor of Leu aminopeptidase, dose not inhibit the aminopeptidase N activitiy. But betulinic acid blocks angiogenesis from the results of tube formation assay and in vivo CAM assay. The angiogenesis blocking mechanism of betulinic acid is supposed to induce apoptosis. These results suggest that curcumin and betulinic acid can be used as angiogenesis blocker and chemopreventive agent of cancer despite of different mechanism.