Ce$O_2$첨가 및 분말처리가 U$O_2$ 분말의 소결에 미치는 영향

김형수,이영우,최창범,양명승,전풍일,Kim, Hyeong-Su,Lee, Yeong-U,Choe, Chang-Beom,Yang, Myeong-Seung,Jeon, Pung-Il 한국재료학회 1993 한국재료학회지 Vol.3 No.3

순수 $UO_2$에 첨가량 변화 및 ball-milling 시간에 따른 (U, Ce)$O_2$ 분말의 특성과 각 조건별로 제조된 분말을 압분 및 소결하여 (U, Ce)$O_2$ 분말 특성에 따른 소결성을 비교 조사하였다. 실험 결과로 부터 ball-milling시간이 길어짐에 따라 입자들은 미세화되고, Ce$O_2$ 함량이 증가할수록 압분, 소결밀도는 저하 하였으며, $CeO_2$는 소결성을 저하시키는 산화물임을 확인하였다. 10wt%,$CeO_2$ 가 첨가된 (U, Ce)$O_2$ 분말의 경우, ball-milling 4시간 수행한 분말의 소결체가 기공의 수도 적고, 구형에 가까왔으며, 소결밀도가 가장 높았다. 이는 4시간 ball-milling한 (U, Ce)$O_2$분말이 비표면적이 크로 그의 packing ratio가 적절하였기 때문이다. We investigated the changes of (U, Ce)$O_2$ powder characteristics with $CeO_2$ contents and ball-milling time and then studied on the sintering properties with those (U, Ce)$O_2$ powder characteristics. From the results of this study, it was concluded that the longer ball-milling time of (U, Ce)$O_2$ powder was, the finer its particle size was. Green and sintered densities were decreased with $CeO_2$ contensts increase. And also $CeO_2$ was recongized deteriorating oxide on the $UO_2$ sintering. In case of the lOwt. % $CeO_2$ contents, (U, Ce)$O_2$ sintered pellet which was made of ball-milled powder for 4 hours had few pores and its pores got near to the sphere. And its sintered density had the highest. Because its powder had higher surface area and its packing ratio was appropriated much better than others.

전신적 항응고제 사용이 어려운 말기신부전 환자에서 헤파린 결합된 Hemophan 투석기를 사용한 혈액투석 - 7년간의 임상 경험

윤수진 ( Yun Su Jin ),김범 ( Kim Beom ),이현희 ( Lee Hyeon Hui ),이영기 ( Lee Yeong Gi ),강우헌 ( Kang U Heon ),김정아 ( Kim Jeong A ),이방훈 ( Lee Bang Hun ),여호명 ( Yeo Ho Myeong ),임영환 ( Im Yeong Hwan ),백현정 ( Baeg Hyeon 대한신장학회 2003 Kidney Research and Clinical Practice Vol.22 No.4

목 적 : 저자들은 양전하를 띤 N, N-diethyl-aminoethyl group이 부착되어 있는 Hemophan 투석기에 음전하를 떤 헤파린을 결합시키는 Gretz 등의 방법을 수정하여 출혈 위험성이 있는 말기신부전 환자에서 헤파린 결합 Hemophan을 이용한 혈액투석법 (hemodialysis using heparin bound Hemophan, HBH-HD)을 보고한 바 있다. 저자들은 지난 7년 동안 출혈 위험성이 있는 말기신부전증 환자들에서 HBH-HD를 시행하였으며 이에 그간의 결과를 종합하여 HBH-HD의 안전성과 효율성을 보고하고자 한다. 방 법 : 저자들은 1995년 4월부터 2002년 4월까지 출혈 위험성이 있는 만성혈액투석환자 159명에서, 헤파린을 결합시킨 Hemophan 투석기 (GFS plus 11, Gambro)를 사용하여 총 1,057회의 HBH-HD를 시행하였다. 투석기나 혈액관 교체가 필요할 정도의 심한 혈액응고 없이 4시간 동안 혈액투석이 가능하였던 40회 투석에서 혈액투석 전, 투석 시작 후 15분, 60분, 120분과 투석 종료 직전 (240분)에 혈중 헤파린 농도와 activated partial thromboplastin time (aPTT)을 측정하였다. 투석의 효율성을 평가하기 위하여 동일 환자에서 시행한 HBH-HD와 이후 헤파린을 전신적으로 사용한 혈액투석 (routine hemodialysis, R-HD) 간의 혈액구획용적(total blood compartment volume, TBCV) 손실과 투석기요소청소율 (K), Kt/V를 비교하였다 (n=20). 결 과 : 1,057회 투석 중 11회 (1.0%)에서는 투석 후 150분 이내에 투석기와 혈액관에 혈액 응고가 발생하어 투석을 증단하였고, 64회 (6.1%)에서는 투석 후 150분부터 230분 사이에 혈액관에 혈액응고가 발생하여 혈액관 교체가 필요하였다. 투석기나 혈액관의 교체가 필요할 정도의 심한 혈액응고 없이 4시간 동안 혈액투석이 가능하였던 982회 증 40회의 투석에서 측정된 헤파린 농도는 투석전 값 (0.11±0.06 U/mL, 평균±표준편차)에 비하여 투석 후 15분 (0.14±0.06 U/mL)에 경미한 증가를 보인 후 (p<0.05), 60분에 0.11±0.05 U/mL, 120분에 0.08±0.04 U/mL, 투석 종료 후 0.08±0.04 U/mL로 감소하였다. 투석 중 aPTT는 투석 전 (44.3±12.9초)에 비하여 투석 후 15분 (49.8±10.5초)에 증가한 후 (p<0.05), 60분에 40.8十7.1초, 120분에 36.1±5.5초, 투석 종료 후 32.1±5.3초로 감소하였다. 두 투석간의 TBCV 손실은 HBH-HD시 17.2±9.6%, R-HD시 2.8±1.2%로 유의한 차이를 보였다 (p<0.0001). 그러나, HBH-HD시 측정한 K값은 136.9±14.6 mL/min, Kt/V는 1.27±0.21로 R-HD의 137.6±18.4 mL/min와 1.20±0.22와 각각 비교하여 볼 때 유의한 차이가 없었다 (p>0.05). 결 론 : 헤파린을 결합시킨 투석막을 사용한 혈액투석법은 출혈 위험성이 있는 말기신부전증 환자들에서 시행할 수 있는 안전하고 효과적인 투석법이다. 그러나 체외 회로에 심한 혈액응고를 완전히 방지하지는 못하므로 투석 중 투석기와 혈액관에서 혈액응고 발생 여부를 감시해야 한다. Objective : Positively charged N,N-diethyl-aminoehtyl groups on Hemophan enable negative charged heparin to be bound with the dialyzer membrane and hemodialysis using heparin bound Hemophan (HBH-HD) could be a hemodialysis modality in patients at risk of bleeding. We designed simplified heparin binding technique and evaluated the bleeding risk and effciency of HBH-HD in chronic renal failure patients at risk of bleeding. Methods : During the period from April 1995 through April 2002, 159 patients at high bleeding risk received 1057 HBH-HD (dialyzer : GFS plus 11, Gambro). The duration of each HBH-HD was standardized to 4 hours at blood-flow rate of 200-250mL/min. To evaluate of HBH-HD, we measured serum heparin concentration (HC) and activated partial thromboplastin time (aPTT) at baseline, 15, 60, 120 minutes and endpoint (240 minutes) (n=40). To evaluate the dialysis effciency, HBH-HD and routine hemodialysis with systemic heparinization (R-HD) were compared for total blood compartment volume (TBCV) loss, dialyzer urea clearance (K) and Kt/V in same study group patients (n=20). Results : Clotting of dialyzer necessitating termination of dialysis occurred in 11 (1.0%) out of 1,057 dialyses at 150 minutes, and clotting requiring change of blood line occurred in 64 dialyses (6.1%) between 150 and 230 minutes. There was a slight increase in the aPTT (mean±SD, 49.8±10.5 sec) and HC (0.14±0.06 U/㎖) at 15 min, compared to predialysis levels of 44.3±12.9 sec and 0.11±0.06 U/㎖, respectively (p>0.05). But no increase in aPTT, HC was observed in measurements at 60 min, 120 min, and at the endpoint. TBCV loss was significantly higher in HBH-HD (mean±SD, 17.2±9.6%), compared to R-HD (2.8±1.2%) (p<0.0001). However, K and Kt/V value (mean±SD) were 136.9±14.6 ㎖/min and 1.27±0.21 in HBH-HD and 137.6±18.4 ㎖/min and 1.20±0.22 in R-HD, showing no significant difference (p>0.05). Conclusion : HBH-HD could be a safe and efficient HD technique in patients at high risk of bleeding. Extracorporeal clotting, however, should be observed cardfully during HBH-HD. (Korean J Nephrol 2003;22(4):389-396)

HaCaT 세포주에서 Epigallocatechin-3-Gallate (EGCG)가 자외선 및 LPS에 의한 iNOS mRNA 발현 및 NO 생성에 미치는 영향

탁우정 ( Tag U Jeong ),이창균 ( Lee Chang Gyun ),서성준 ( Seo Seong Jun ),김명남 ( Kim Myeong Nam ),노병인 ( No Byeong In ),홍창권 ( Hong Chang Gwon ) 대한피부과학회 2004 대한피부과학회지 Vol.42 No.1

N/A Background: Nitric oxide (NO) plays an important role in inflammation and multiple stages of carcinogenesis. Green tea (Camellia sinensis polyphenols are potent antiinflammatory agents and have been shown to inhibit NO production in tumor cell lines. In the present study, we examined the effect of epigallocatechinp-3-gallate (EGCG), a generation of NO in HaCaT cells. Methods: HaCaT cells were treated with 10μM EGCG and 100μM NAC for 1 hour. 1 hour later, they were irradiated with 50mJ/cm^2 UVB and treated with 200 u㎍/ml LPS for 12 hours, respectively. The iNOS mRNA was determined by reverse transcription-polymerase chain reaction (RT-PCR) and NO production was assessed by spectrophotometric method based on Griess reaction. Nuclear factor κB (NF-κB) binding activity was determined by electophoretic mobility shift assay (EMSA). Results: The results were as follows 1. EGCG inhibited UVB and LPS induced expression of inducible nitric oxide synthase. 2. HaCaT cells cotreated with EGCG produced significantly less iNOS mRNA and NO compared with HaCaT cells stimulated with UVB irradiation of LPS. 3. The inhibition of iNOS mRNA and NO production correlated with the suppression of expression of NF-κB dependent gene iNOS. 4. EGCG inhibited the activation and translocation of NF-κB to the nucleus Conclusion: inhibited the activation and translocation of NF-κB to the nucleus in HaCaT cells by interfering with the activation of NF-κB through a novel mechanism. Our results further suggest that EGCG may be therapeutically effective in UVB and cytokine induced cutaneous inflammation. (Korean J Dermatol 2004;42(1):37~46)

Zinc stearate의 첨가가 $UO_{2}$분말의 겉보기밀도, 혼합 및 성형에 미치는 효과

나상호,김시형,이영우,양명승,손동성,Na, Sang-Ho,Kim, Si-Hyeong,Lee, Yeong-U,Yang, Myeong-Seung,Son, Dong-Seong 한국재료학회 1995 한국재료학회지 Vol.5 No.4

윤활제인 zinc stearate의 첨가량 (0~4wt%)을 변화시켜 U$O_{2}$분말의 겉보기밀도, 성형시의 분말입자간 마찰과 입자/다이벽 마찰간의 상관관계를 조사하였다. 소량의 윤활제 첨가시에는 U$O_{2}$분말입자간 박막의 윤활제 도포층이 형성되어 겉보기밀도가 증가한 반면 다량의 윤활제를 첨가한 경우에는 U$O_{2}$ 분말입자에 두꺼운 윤활제 도포층이 형성되고 미혼합된 윤활제가 존재하여 겉보기밀도는 감소하는 경향을 보였다. 윤활제를 첨가혼합한 상태에서 다이벽 윤활도포 유무에 따라 구한 U$O_{2}$ 성형체의 성형압력/성형밀도 자료로부터 분말입자간 마찰, 입자/다이벽 마찰 그리고 성형시 lubrication/inhibition등의 상대적 중요성을 조사하였다. 입자/다이벽 마찰에 의한 압력손실은 입자간 마찰에 의한 압력손실보다 크게 나타났다. 입자/다이벽 마찰에 의한 압력손실은 다이벽 윤활제 도포에 의해 최소화될 수 있지만 상대적으로 바람직하지 않은 성형시의 inhibition이 야기되는 것으로 나타났다.

HBV : Retrospective Observational Study to Evaluate the Efficacy of Entecavir in Patients with Chronic Hepatitis B Virus Infection in Korea: Real-Life Clinical Outcomes

( Chung-Hwa Park ),( Sung Won Lee ),( Hee Yeon Kim ),( Do Seon Song ),( Hyun Jin Kim ),( Myeong Jun Song ),( Jung Hyun Kwon ),( Chan Ran You ),( Jeong Won Jang ),( U Im Chang ),( Chang Wook Kim ),( So 대한간학회 2013 춘·추계 학술대회 (KASL) Vol.2013 No.1

Background: Entecavir, has demonstrated superior histologic, virologic, and biochemical benefit. Still, its long-term clinical outcome is not well established in the Korean clinical area, and also in subjects who stopped the treatment. Methods: This is a multicenter, retrospective cohort observational study to evaluate the efficacy of Entecavir long-term treatment in CHB patients at hospitals affiliated to the Catholic University of Korea through analysis of the electronic medical record data from January 1, 2006 to December 31, 2012. Results: Among 2,440 patients prescribed with entecavir 0.5mg qd, 1,337 patients were treatment naive. Excluding 533 patients with concomitant conditions, 578 patients were ontreatment and 226 patient stopped entecavir during the study period. At 6mo, year 1, 2, 3, 4 and 5, cumulative incidences of complete virologic response (HBV-DNA < 300 copies/mL) was 379, 530, 573, 577, 579 and 579, respectively. HBsAg loss rate was 9.86%, and among 440 HBeAg-positive patients, HBeAg loss rate and HBeAg loss with HBeAb positivity rate was 20.00% and 17.43%, respectively, at year 1. During the study period, 226 patients stopped entecavir, and at year 1 after cessation, cumulative virologic relapse (HBV-DNA>10^4 copies/ mL) and biochemical relapse (ALT>40 U/L) were 22.57% and 20.35%, respectively with mean days of 191.06±67.0 and 188.39±90.15, respectively. Prognotsic factor for earlier CVR was HBV-DNA<10^7cpm at initiating entecavir (P<0.005). Among those who stopped the medication, prognostic factor for virological relapse was HBV-DNA ≥10^7cpm at initiating entecavir (P=0.022). Conclusions: Long term use of entecavir may achieve CVR in most patients, and patients with higher viral load should be considered of indefinite duration of treatment regardless of age, sex, biochemical markers or HBeAg status.

관개용 저수지 물관리의 최적화 방안 : 요약

우장명 ( U Jang Myeong ),이준배 ( Lee Jun Bae ) 충북개발연구원 2003 충북연 Vol.2003 No.6

발간사

우보명 ( U Bo Myeong ) 한국환경복원기술학회 1998 한국환경복원기술학회지 Vol.1 No.1

충북 농업 경쟁력과 발전 방안

우장명 ( U Jang Myeong ),박종은 ( Park Jong Eun ) 충북개발연구원 2002 충북연 Vol.2002 No.7

고정밀 저가 휴대용 경도기 개발

성명우(Myeong-U Seong),류지열(Jee-Youl Ryu) 한국정보기술학회 2018 한국정보기술학회논문지 Vol.16 No.1

This paper presents high-precision low-cost digital portable hardness tester using the Leeb rebound hardness test method. The Leeb rebound test method is generally easier to measure, and more accurate than other types of hardness testing methods. This method is used on all metals, except in condition where the test metal structure or surface conditions would introduce too much variations. This portable method is also used for testing efficiently hardness of surface and unreachable edges of large metal workpiece(mainly above 1kg). The proposed hardness tester consists of sensor probes(impact devices) of 7-type to measure Leeb rebound and embedded system unit for its control and signal processing. This hardness tester showed resolution of more than 20%, measurement accuracy of more than 25%, cost effective of 33% and response time of 15msec for the various test samples as compared to conventional hardness tester. We believe that this tester is widely used in the metal industries to measure hardness.

벌채지내 운재로의 토양물리성 및 식생의 회복과정 -운재로 개설이후 9년 경과의 경우-

우보명 ( U Bo Myeong ),김경훈 ( Kim Gyeong Hun ),박재현 ( Park Jae Hyeon ),최형태 ( Choe Hyeong Tae ) 한국환경복원기술학회 1998 한국환경복원기술학회지 Vol.1 No.1