쿠싱증후군 환자에서 당 대사 이상 정도에 따른 인슐린 감수성과 인슐린 저항성의 변화

정인경,김성훈,정재훈,민용기,이명식,이문규,유형준,안규정,노정현,김동준,김광원 대한내분비학회 2003 Endocrinology and metabolism Vol.18 No.4

연구배경 당질 코르티코이드는 당 대사에 매우 중요한 호르몬으로 내인성 당질 코르티코이드 과다상태인 쿠싱증후군에서는 말초조직에서 인슐린 저항이 증가하고 이를 보상하고자 인슐린 분비의 증가로 고인슐린혈증이 동반된다고 보고되고 있다. 하지만 생체 내에서와 달리 시험관내에서는 췌도세포에 당질 코르티코이드를 장시간 처리하면, 인슐린 분비 및 생합성이직접적으로 억제됨이 확인된 바 있어 쿠싱증후군 환자에서 당뇨병의 원인으로는 아마도 말초조직에서 증가된 인슐린 저항성 뿐 아니라 이를 충분히 보상하지 못하는 췌장에서의 인슐린 분비 저하가 같이 동반되어있지 않을까 하는 가설을 세우게 되었고, 아직까지 당질코르티코이드가 당대사 이상을 일으키는 기전에 대해 쿠싱증후군을 당대사 정도에 따라 인슐린 감수성과 분비능을 분석한 연구는 없었기에 이를 알아보고자 하였다. 방법: 삼성서울병원에서 쿠싱증후군으로 진단 받은 환자 15명을 대상으로 하였다. 이에 대한 대조군으로는 쿠싱증후군 환자와 같은 성별 그리고 체질량지수를 갖은 15명의 건강한 성인을 대상으로 비교 하였다 쿠싱증후군 환자를 대상으로 경구당부하 검사를 통해 당대사 정도를 정상군, 내당능장애군, 그리고 당뇨병군으로 나눈 후 정맥 당부하 검사를 시행하여 각군의 인슐린 저항성과 인슐린 분비능의 지표를 비교하고, 수술 후 쿠싱증후군이 완치된 상태에서 수술 전후의 당대사 지표의 변화를 조사하였다. 결과: 1) 쿠싱증후군 환자 중 정상인은 20%, 내당능 장애는 27%, 그리고 당뇨병은 53%였다. 체질량지수, 나이, 그리고 발병 기간은 세 군간에 의미 있는 차이가 없었으나, 24시간 소변검사의 코르티솔 농도는 당뇨병군에서 의미있게 높았다. 2) 정맥당부하 검사 결과, 인슐린 감수성 지표인 Sl는쿠싱증추린」서 1.58±0.10[×10^(-4)(min^(-1)(μU/mL)^(-1)]로 정상 대조군의 3.37±0.49[×10^(-4)(min^(-1)(μU/mL)^(-1)]에 비해 의미있게 낮았으나(P=0.024), 쿠싱증후군 환자 중 NGT, IGT, DM 군간에 서로 통계적인 차이는 없었다. 3) SG는 정상 대조군과 쿠싱증후군 환자간에는 의미있는 차이가 없었고, 쿠싱 증후군에 있어서 당대사가 악화될수록 감소하는 경향을 보였으나 의미있는 차이는 없었다. 4) 인슐린 분비능의 지표인 AIRg는 정상인에 비해 전체 쿠싱증후군 환자의 경우 증가하는 경향을 보였으나 의미있는 차이는 없었다. 하지만 쿠싱증후군 환자중에서 당대사 상태에 따라 NGT군은 1299 (1297∼1310)(mu/g/min ×10^(-2))로 정상 대조군(368.9±98.6[mu/g/min ×10^(-2)]) 보다도 의미있게 높았고, DM군{202.2 (91.1~371.4) [mu/g/min ×10^(-2)}은 NGT군에 비해 의미있게 낮았다(P=0.0031). 5) 15명중 현재 완치 상태에 있는 6명에 대해 수술전과 후로 비교하였다. 수술 전 당대사 상태가 1명은정상, 1명은 내당능 장애, 그리고 4명은 당뇨병이었으나 수술 후 시행한 경구 당부하 검사상 모두 정상 당대사 상태를 보였다. 6) 수술 후 완치된 환자 6명에 있어 인슐린 감수성지표인 Sl는 수술전에 중앙값이 1.22[×10^(-4)(min^(-1)(μU/mL)^(-1)]로 대조군에 비해 의미있게 감고』어 있었으나(p.0.05), 수술후 10.95 [×10^(-4)(min^(-1)(μU/mL)^(-1)]로 정상 수준으로 회복되었고(P=0.0022), 인슐린 분비능을 나타내는 AIRg [mu/g/min ×10^(-2)] 값도 정상수준으로 회복되었다. 특히 인슐린 분비능의 회복양상은 혈당농도에 따라 판이하게 나타나서, 정상과 내당능장애 상태에 있던 2명은 수술전에 1201 [mu/g/min ×10^(-2)]로 증가되어 있던 AIRg 값이 수술 후 정상 수준으로 감소하였고, 수술 전에 당뇨병 상태에 있던 4명의 경우 245.9 [mu/g/min ×10^(-2)]로 인슐린 분비능이 감고il어 있었는데 이들은 수술 후 모두 정상 수준으로 증가되었다 (P=0.0286). 결론: 쿠싱증후군 환자에서 당대사 이상은 80%로 높은 유병률을 보였다. 모든 쿠싱증후군환자에서 인슐린 감수성은 정상인에 비해 저하되어 있어 말초조직의 인슐린 저항이 선행됨을 시사하며, 인슐린 분비능은 당대사의 정도에 따라 다르게 나타났는데, 정상 당대사군에서는 인슐린의 저항성을 극복할 만큼 정상 대조군보다 더 많은 양의 인슐린 분비를 하다가 고코르티솔혈증이 심할수록 인슐린 분비능의 감소로 당뇨병으로 진행됨을 확인할 수 있었고, 이런 인슐린 저항성과 인슐린 분비장애는 수술 후 다시 회복되는 가역적인변화를 보였다. Background: Glucocorticoid plays an important role in the control of carbohydrate metabolism. Patients with Cushing's syndrome have been reported to have an increased incidence of carbohydrate intolerance due to peripheral insulin resistance and hyperinsulinemia, although the exact incidence and nature of this disorder have remained unclear. Few results have been published about insulin resistance and insulin secretion according to the level of glucose concentration, or about the reversibility of such defects in patients with Cushing's syndrome. Methods: To assess the effect of glucocorticoid on the insulin sensitivity and insulin secretion in Cushing's syndrome, 15 patients with Cushing's syndrome were classified into 3 groups (normal glucose tolerance: NGT, impaired glucose tolerance: IGT, diabetes: DM) according to the degree of glucose tolerance based on the oral glucose tolerance test (OGTT). Insulin modified, frequently sampled, intravenous glucose tolerance test (FSIGT) was performed before and after curative surgery on these patients and on 15 healthy control subjects. Data were evaluated by non-parametric statistical analysis. Results: 1) Among the 15 patients with Cushing's syndrome, 3 (20%) were NGT, 4 (27%) IGT, and 8 (53%) DM, based on OGTT. Twenty-four hour urinary free cortisol (UFC) was significantly higher in the DM group. 2) Insulin sensitivity index (SI) of Cushing's syndrome was significantly lower than that of the control group p=0.0024), but was not significantly different among the three Cushing's syndrome groups of NGT, IGT and DM. 3) Glucose mediated glucose disposal (SG) (Ed- confirm this abbreviation; it does not seem to match the definition) of Cushing's syndrome was not significantly different from that of the control group. 4) Insulin secretion (AIRg) of Cushing's syndrome tended to be high, but it was not significantly different from that of control. However, according to the level of glucose concentration there was significant difference in AlRg among the three Cushing's syndrome groups p=0.0031); AIRg of DM was significantly lower than that of NGT. 5) After surgical treatment, parameters of insulin sensitivity and insulin secretion were normalized in 6 cured patients; 1 with NGT, 1 with IGT, and 4 with DM, preoperatively. Median SI of all 6 patients was significantly improved up to the normal range postoperatively p=0.0022). Median AIRg of these 6 patients was balanced around that of normal control postoperatively p=0.0286). Conclusion: Eighty percent of patients with Cushing's syndrome had abnormality of carbohydrate metabolism. Insulin sensitivity was significantly decreased in Cushing's syndrome. Insulin secretion was significantly higher only in the NGT and IGT groups of Cushing's syndrome. As the hypercortisolemia is exacerbated, insulin secretion is significantly decreased and causes DM, suggesting that glucocorticoid has a direct or indirect toxic effect on the pancreatic beta cell (J Kor SOC Endocrinol 18:392-403, 2003).

신장기능영상용 방사성의약품 Bz - MAG3 ( Benzoylmercaptoacetylglycylglycylglycine ) 의 키트화 및 체내분포

고창순(Chang Soon Koh),이명철(Myung Chul Lee),정준기(June Key Chung),이동수(Dong Soo Lee),김영주(Young Ju Kim),정재민(Jae Min Jeong),장영수(Young Soo Chang),조정혁(Jung Hyuk Cho) 대한핵의학회 1996 핵의학 분자영상 Vol.30 No.3

N/A The MAG3 is a tubular excreting radiopharmaceutical for renal image. We synthe-sized benzoyl MAG3 (Bz-MAG3) and made a kit for labeling with Tc-99m. We checked the labeling effeciency of Tc-99m labeled MAG3 and biodistribution. Labeling efficiency was checked by TLC- SG (acetonitrile/H2O=2/1). After injecting of 1 mCi of Tc-99M-MAG3 to ICR-mice, Tmax(min), T1/2(min) were obtained in the renogram. Sequencial images (30sec, 2min, 5min, 10min, 15min, 20min) of TC-99m-MAG3 were compared with those of commercial Tc-99m-DTPA (Du Pont Merck Pharmaceutical Co.) kit. 1) The Rf value of synthesized Tc-99m-MAG3 was 0.78 and labeling efficiency was 97.5±1.9% (n=10). 2) The dynamic images of the Tc-99m-MAG3 were better than those of the Tc-99m-DTPA. 3) The Tmax(min.) and T1/2(min.) of Tc-99m-MAG3 (n=10) were 1.5±0.5 (left), 1.4±0.4(right), and 4.3±1.4 (left), 4.8±2.0 (right), respectivel. The Tmax(min.) and T1/2(min.) of Tc-99m-DTPA (n=7) were 2.7±1.6 (left), 2.7±1.6 right), and 3.8±1.7 (left), 4.5±2.7 (right), respectively. The quaility of image and labeling efficiency of the synthesized Bz-MAG3 kit were excellent, that it was supposed to be used in routine clinical work.

배지의 종류와 부피가 절화 장미 ‘Red Sandra’와 ‘Little Marble’ 삽목시 발근 및 생장에 미치는 영향

정종운(Jong Woon Jeong),김경희(Gyeong Hee Kim),황승재(Seung Jae Hwang),박수민(Su Min Park),정병룡(Byoung Ryong Jeong) (사)한국생물환경조절학회 2005 생물환경조절학회지 Vol.14 No.2

본 연구는 배지의 종류 및 부피가 절화 장미의 발근과 발근 후 생육에 미치는 영향을 알아보기 위하여 수행하였다. 실험은 유리온실의 철재 베드에 높이 1.5m의 아치형 터널을 설치하고 습도유지를 위하여 fog(200sec./5min. or 100sec./5min) 가습하고, 삽목초기에 차광률 55%의 한랭사로 차광하였다. 실험재료는 Rosa hybrida ‘Red Sandra’와 ‘Little Marble' 두 품종을 사용하였다. 배지의 종류에 따른 발근 차이를 알아보기 위하여 10가지 배지(토실이 상토, 암면큐브, phenolic foam, perlite, vermiculite, 또는 perlite와 peatmoss 1 : 1, perlite와 coir 1 : 1, perlite와 rockwool 1 : 1, rockwool과 peatmoss 1 : 1, rockwool과 coir 1 : 1, v/v)를 준비하여 삽목하였다. 발근배지의 부피에 따른 발근 및 생육의 차이를 알아보기 위하여 3가지의 배지(토실이 상토, 암면큐브, phenolic foam)를 각각 3가지 부피(3 × 3 × 3cm, 5 × 5 × 5cm, 7 × 7 × 7cm)에 삽목하였다. 배지의 종류를 달리한 실험은 두 품종 모두에서 Rockwool 1: Peatmoss 1 배지에서 발근과 생육에서 가장 좋은 결과가 나타났으며, 배지의 부피에 따른 발근율과 모든 생육은 배지의 용적이 커질수록 좋았다. Experiments were conducted to measure rooting and growth of rose cuttings as affected by medium composition and volume. Rosa hybrid a 'Red Sandra' and 'Little Marble' were used as test plants. For medium composition test, rockwool, phenolic foam, perlite, vermiculite, peatmoss, coir and a commercial medium (Tosilee medium) were applied in single or mixed forms on the propagation bed with fog (200 sec./5 min.) installed to control the humidification time. 'Red Sandra' and 'Little Marble' cuttings were planted in 16-cell plastic pots and 72-cell plug trays, respectively. For the medium volume test, 72-cell plug trays and 16-cell or 9-cell plastic pots were used. Cuttings with an uniform node with a five-leaflet leaf was soaked in a 500 ㎎ㆍL?¹ IBA solution for 30 sec. A fogging system installed on the propagation bed was used for (100 sec./5 min.). Rockwool 1 : peatmoss 1 (v/v) was the most effective on growth and rooting for both cultivars and high volume of Tosilee medium and rockwool were most effective media for both cultivars.

배지의 종류와 부피가 절화 장미 ‘Red Sandra’와 ‘Little Marble’ 삽목시 발근 및 생장에 미치는 영향

정종운(Jong Woon Jeong),김경희(Gyeong Hee Kim),황승재(Seung Jae Hwang),박수민(Su Min Park),정병룡(Byoung Ryong Jeong) (사)한국생물환경조절학회 2007 생물환경조절학회지 Vol.16 No.4

본 연구는 배지의 종류 및 부피가 절화 장미의 발근과 발근 후 생육에 미치는 영향을 알아보기 위하여 수행하였다. 실험은 유리온실의 철재 베드에 높이 1.5m의 아치형 터널을 설치하고 습도유지를 위하여 fog(200sec./5min. or 100sec./5min) 가습하고, 삽목 초기에 차광률 55%의 한랭살 차광하였다. 실험재료는 Rosa hybrida ‘Red Sandra’와 ‘Little Mable’ 두 품종을 사용하였다. 배지의 종류에 따른 발근 차이를 알아보기 위하여 10가지 배지(토실이 상토, 암면큐브, peatmoss 1:1, perlite와 coir 1;1, perlite와 rockwool 1;1, rockwool과 peatmoss 1;1, rockwool과 coir 1;1, v/v)를 준비하여 삽목하였다. 발근배지의 부피에 따른 발근 및 생육의 차이를 알아보기 위하여 3가지의 배지(토실이 상토, 암면큐브, phenolic foam)를 각각 3가지 부피(3×3×3㎝, 5×5×5㎝, 7×7×7㎝)에 삽목하였다. 배지의 종류를 달리한 실험은 두 품종 모두에서 Rockwool l: Peatmoss l 배지에서 발근과 생육에서 가장 좋은 결과가 나타났으며, 배지의 부피에 따라 발근율과 모든 생육은 배지의 용적이 커질수록 좋았다. Experiments were conducted to measure rooting and growth of rose cuttings as affected by medium composition and volume. Rosa hybrid a ‘Red Sandra’ and ‘Little Marble’ were used as test plants. For medium composition test, rockwool, phenolic foam, perlite, vermiculite, peatmoss, coir and a commercial (Tosilee medium) were applied in single or mixed forms on the propagation bed with fog (200 sec./5 min.) installed to control the humidification time. ‘Red Sandra’ and ‘Little Marble’ cuttings were planted in 16-cell plastic pots and 72-cell plug trays, respectively. For the medium volume test, 72-cell plug trays and 16-cell or 9-cell plastic pots were used. Cuttings with an uniform node with a five-leaflet leaf was soaked in a 500 ㎎ㆍ L ?¹ IBA solution for 30 sec. A fogging system installed on the propagation bed was used for (100 sec./5 min.) Rockwool l : peatmoss l (v/v) was the most effective on growth and rooting for both cultivars and high volume of Tosilee medium and rockwool were most effective media for both cultivars.

Dimethylnitrosamine 유발 급성 간 손상 흰쥐에서 ^(99m)Tc-Lactosylated Serum Albumin을 이용한 간 기능의 평가

정신영,이재태,서명랑,유정아,배진호,안병철,황재석,정재민,하정희,이규보 대한핵의학회 2003 핵의학 분자영상 Vol.37 No.6

목적: ^(99m)Tc-lactosylated serum albumin (^(99m)Tc-LSA)은 간세포에 특이적으로 결합하는 간수용체 영상용 방사성의약품으로 새로이 합성되었다. 간섬유화를 유발하는 dimethylnitrosamine (DMN)을 투여한 간 손상 휜쥐 모델에서 ^(99m)Tc-LSa의 역동학적인 간섭취를 조사하고 간효소치의 변화와 조직학적 소견을 비교하여, LSA의 간섭취가 간기능의 변화를 반영하는지를 연구하였다. 대상 및 방법: SD계 흰쥐에 DMN를 27 mg/kg으로 복강 내 주사하여 급성 간손상을 유도하고 대조군과 비교하였다. DMN을 주사한 흰쥐를 3일(DMN-3), 8일(DMN-8), 21일(DMN-21)에 ^(99m)Tc=LSA (1,665 mg/kg) 29 MBq를 정맥 주사하여, 30분 동안 동적 영상을 획득하고 간과 신장부위에 관심영역을 설정하여 간과 심장부위의 시간방사능 곡선을 얻었다. 간기능 평가를 위해 시간방사능 곡선을 이용하여 간섭취지수와 혈중제거지수를 구하였고 곡선 최적화를 시행하였다. DMN 투여군과 대조군의 간효소치의 변화와 간조직의 광학현미경 소견을 비교하였다. 결과: 대조군에서는 ^(99m)Tc-LSA가 빠르게 간에 섭취되고 혈중에서 제거되었으나 DMN을 처리한 군에서는 간섭취가 낮았다. 간섭취지수의 비교에서 대조군에 비해 DMN 처리군에서 유의하게 간섭취지수가 낮았다(DMN-3: 0.842, DMN-8: 0.898, DMN-21: 0.91, 대조군: 0.96, p<0.05). 혈중제거지수의 비교에서도 대조군에 비해 DMN 처리군에서 혈중제거지수가 유의하게 높았다(DMN-3: 0.731, DMN-8: 0.654, DMN-21: 0.604, 대조군: 0.473, p<0.05). 비선형 회귀분석에서 R_(2) 값은 0.9이상으로 좋은 일치를 보였고, 대조군에ㅓ K값이 DMN처리군에 비해 크고(DMN-3: 0.28, DMN-8: 0.41, DMN-21: 0.46, 대조군: 0.97, p<0.05), T_(1/2)값은 작았다(DMN-3: 2.5, DMN-8: 1.7, DMN-21: 1.5, 대조군: 0.7, p<0.05). 간효소치의 변화는 DMN-3군에서는 대조군에 비해 상승하였으나 DMN-8, DMN-21군에서는 간효소치의 상승이 관찰되지 않았다. 간조직 소견의 경우 DMN-3군에서 중심정맥 주위에 괴사가 관찰되었으나 DMN-8군, DMN-21군에서는 미약한 정도의 염증세포 침윤만이 관찰되었다. 결론: ^(99m)Tc-LSA 간신티그래피의 간섭취 정도는 간손상과 반비례하였으며 간섭취의 변화는 조직학적 손상이 심한 정도와 간손상후 회복되는 과정을 반영하여 주었다. ^(99m)Tc-LSA 간신티그래피가 간손상을 평가하고 간손상후 회복되는 과정을 추적하는 간수용체 영상용 방사성 의약품으로 사용될 수 있을 것으로 생각된다. Objects: ^(99m)Tc-lactosylated human serum albumin(LSA) is a newly synthesized radiopharmaceutical that binds to asialoglycoprotein receptors, which are specifically presented on the hepatocyte membrane. Hepatic uptake and blood clearance of LSA were evaluated in rat with acute hepatic injury induced by dimethylnitrosamine(DMN) and results were compared with corresponding findings of liver enzyme profile and these of histologic changes. Materials and Methods: DMN (27 mg/kg) was injected intraperitoneally in Sprague-Dawley rat to induce acute hepatic injury. At 3(DMN-3), 8(DMN-8), and 21(DMN-21) days after injection of DMN, LSA injected intravenously, and dynamic images of the liver and heart were recorded for 30 minutes. Time-activity curves of the heart and liver were generated from regions of interest drawn over liver and heart area. Degree of hepatic uptake and blood clearance of LSA were evaluated with visual interpretation and semiquantitative analysis using parameters (receptor index : LHL3 and index of blood clearance : HH3), analysis of time-activity curve was also performed with curve fitting using Prism program. Results: Visual assessment of LSA images revealed decreased hepatic uptake in DMN treated rat, compared to control group. In semiquantitative analysis, LHL3 was significantly lower in DMN treated rat group than control rat group (DMN-3:0.842, DMN-8: 0.898, DMN-21: 0.91, Control: 0.96, p<0.05), whereas HH3 was significantly higher than control rat group (DMN-3: 0.731, DMN-8: 0.654, DMN-21: 0.604, Control: 0.473, p<0.05). AST and ALT were significantly higher in DMN-3 group than those of control group. Centrilobular necrosis and infiltration of inflammatory cells were most prominent in DMN-3 group, and were decreased over time. Conclusion: The degree of hepatic uptake of LSA was inversely correlated with liver transaminase and degree of histologic liver injury in rat with acute hepatic injury.

Variation of Harbor Oscillations in Yeongil Bay

Min­Su Jeon,Joong­Woo Lee,Jae­Hyun Jeong,Sang­Yong Yang,Young­Hwan Jeong 한국항해항만학회 2006 한국항해항만학회 학술대회논문집 Vol.1 No.-

  Today, harbor oscillation problems are the most significant factor to consider when designing harbors serving very large ships. In coastal harbors, large vessels moored in the elastic hawsers are often displaced due to the resonance between long period waves and mooring systems. As a result, cargo handling may be interrupted and the hawsers may be broken, especially when the amplification becomes extreme. The most significant harbor confronted with harbor oscillation problem in Korea is Pohang New port. Many cases of problems are being reported by the pilot association and the local office of MOMAF (Ministry of Maritime Affairs and Fisheries). However, it is difficult to prevent the arrival of long waves causing oscillation within this harbor. Moreover, the Korean government has already started a new port plan at the mouth of Yeongil Bay without addressing the problems that have occurred in Pohang New port. This study deals with the variation of harbor oscillation due to the construction of a 4.1 km breakwater at the bay mouth including the arrangement of the new berths. Numerical methods used are in fairly standard form from the extended mile slope equation. The obtained numerical results were compared with field measurement from the previous and this will bring a certain level of discussion and consideration of variation to the future port development.

분변토를 이용한 VOCs 흡착에 관한 기초연구

김재홍,손희정,김장호,김수생,서정민 동아대학교 환경문제연구소 1997 硏究報告 Vol.20 No.2

This study was carried out two point view that reuse of sludge and adsorption of benzene, toluene and o-xylene of VOCs in cast, carbonized cast and activated carbon. The cation exchange capacity of cast and carbonized cast were 59.2, 112 meq/l00g, respectively. The specific surface were 560, 800 ㎡/g, respectively. The average removal rates of benzene by 50g cast of 50% hydrous cast, anhydrous cast, carbonized cast, activated carbon were 15.0, 41.2, 88.2, 99.4% in 60min retention time. The average removal rates of toluene by 50g cast of 50% hydrous cast, anhydrous cast, carbonized cast, activated carbon were 12.5, 34.2, 88.2, 99.5% in 60min retention time. The average removal rates of o-xylene 50g cast of 50% hydrous cast, anhydrous cast, carbonized cast, activated carbon were 8.8, 28.5, 84.8, 98.1% in 60min retention time. The adsorption efficiency of test absorbent was in order of benzene > toluene > o-xylene.

Purification and Characterization of Helicobacter pylori ${\gamma}$-Glutamyltranspeptidase

Song, Jae-Young,Choi, Yeo-Jeong,Kim, Jeong-Min,Kim, Yoo-Ree,Jo, Jin-Seong,Park, Jin-Sik,Park, Hee-Jin,Song, Yun-Gyu,Lee, Kon-Ho,Kang, Hyung-Lyun,Baik, Seung-Chul,Youn, Hee-Shang,Cho, Myung-Je,Rhee, Kw The Korean Society for Microbiology 2011 Journal of Bacteriology and Virology Vol.41 No.4

Gamma-glutamyltranspeptidase (GGT) was purified to electrophoretic homogeneity from the cell extract of H. pylori. The purified enzyme consisted of heavy and light subunits with molecular weights of 38 kDa and 21 kDa, respectively. N-terminal amino acid sequence of heavy and light subunits revealed that H. pylori GGT was processed into 3 parts for a signal peptide of 27 amino acid residues, a heavy subunit of 352 residues, and a light subunit of 188 residues during translation. The reaction rate for hydrolysis of ${\gamma}$-GpNA was 84.4 ${\mu}mol/min$ per milligram of protein, and that for the ${\gamma}$-glutamyl transfer from ${\gamma}$-GpNA to gly-gly was 23.8 ${\mu}mol/min$ per milligram of protein. The apparent Km values of H. pylori GGT for ${\gamma}$-glutamyl compounds were on the order of $10^{-3}$ to $10^{-4}$ M and those for acceptor peptides and amino acids were on the order of $10^{-1}$ to $10^{-2}$ M. The GGT protein kept approximately 80% of the initial enzymatic activity on incubation at $60^{\circ}C$ for 15 min. The optimum temperature and pH for reactions of both hydrolysis and transpeptidation were $40^{\circ}C$ and 9.0, respectively. The transpeptidation and hydrolysis reactions catalyzed by H. pylori GGT were strongly inhibited by L-Gln and moderately inhibited by L-Ala, L-Ser, ${\beta}$-chloro-L-Ala, and L-Glu. These results demonstrated that the biochemical properties of H. pylori GGT are different from those of other bacterial GGTs. Further, H. pylori GGT might degrade glutathione in the gastric mucous layer of humans if the enzyme could be secreted in the bacterial niches.

이동형 스크러버를 이용한 암모니아 및 톨루엔의 제거 효율

김재영 ( Jae-young Kim ),김장윤 ( Jang-yoon Kim ),이연희 ( Yeon Hee Lee ),김민선 ( Min Sun Kim ),김민수 ( Min-su Kim ),김현지 ( Hyun Ji Kim ),류태인 ( Tae In Ryu ),정재형 ( Jae Hyeong Jeong ),황승율 ( Seung-ryul Hwang ),김균 ( Ky 한국환경농학회 2018 한국환경농학회지 Vol.37 No.1

본 연구는 국내에서 다량 취급되고 있는 암모니아 및 톨루엔을 흄 상태로 노출시킨 후 흡수/흡착방법을 달리한 이동형 스크러버를 이용해 각 유해화학물질의 제거효율을 비교 분석하였다. 이동형 스크러버는 기 개발된 장치를 개선하여 와류세정에 의한 흡수, 유입풍속 조절의 장점을 살리고, 활성탄 및 카본필터를 통한 기체상 유해화학물질의 흡착방법 도입을 통해 단점을 보완하였다. 개선된 장치는 기초성능평가를 통해 적정 제어풍속이 검증되었고, 5% 암모니아수 용액을 흄 상태로 노출시켜 후드 흡입부, 송풍기 배출부 및 세정기가 정상 작동함을 확인하였다. 흡수/흡착방법에 따른 암모니아 제거효율은 90분 경과 후 C≥PCA>SWA 순으로 가장 우수한 SWA 군의 노출 농도별 제거 효율은 시간이 경과할수록 노출 농도와 무관하게 배출 농도는 증가되었고, 세정액의 pH는 산성에서 염기성으로 변화되었다. 또한, 시간 경과에 따른 노출 농도 별 세정액의 pH 변화와 배출구 농도 변화 사이에 0.9429~0.9491 수준의 정의 상관관계를 나타내었다. 흡착방법에 따른 톨루엔의 제거 효율은 초기 10분 경과 후 배출구농도에서 C>CMA≥GCA 순을 나타내다 90분 경과까지 일정한 농도로 유지되었다. 가장 우수한 GCA 군의 노출 농도 별 제거 효율은 초기 10분 경과 시 노출 농도에 비례하여 배출 농도가 높은 경향이었다. 이와 같은 결과를 통해 개선된 이동형 스크러버는 중화반응에 의해 산성 또는 염기성 유해화학물질의 제거뿐 아니라, 활성탄 등의 흡착기능 개선을 통해 VOCs 제거에도 효과적이었다. 하지만, 실제 현장에서 활용이 가능하도록 세정액 pH를 지속적으로 유지하여 연속적으로 흡수 제거할 수 있는 방법과 노출되는 화학물질 농도와 흡착제의 관계에서 파괴점, 포화점, 흡착속도 등의 물리적인 요소가 추가적인 연구를 통해 도출되어야 할 것이다. BACKGROUND: The mobile vortex wet scrubber was developed to remove the harmful chemicals from accidental releases. However, there was a disadvantage that it was limitedly used for volatile organic compounds (VOCs) such as toluene according to the physicochemical properties. This study compared the removal efficiencies of an improved mobile scrubber on toluene and ammonia by applying diverse adsorption and absorption methods. METHODS AND RESULTS: The removal efficiencies on harmful chemicals were examined using various adsorption and absorption methods of water vortex process (C), phosphoric acid-impregnated activated carbon adsorption (PCA), pH-controlled water (pH 2.5) vortex process absorption with sulfuric acid (SWA) after ammonia exposure, granular activated carbon adsorption (GCA), and activated carbon mat adsorption (CMA) after toluene exposure. As a result, the best removal efficiency was shown in the SWA for ammonia and GCA for toluene. Also, the SWA and GCA methods were compared with different concentration levels. In the case of ammonia exposure (5, 10 and 25%), there was no difference by concentration levels, and the concentration in the outlet gradually increased, with pH change from acid to base. In the case of toluene exposure (50, 75 and 100%), the outlet concentration was higher relative to the exposure concentration in the initial 10 min, but the outlet concentration was remained steady after 10 min. CONCLUSION: The newly improved mobile scrubber was also effective in removing VOCs through adsorption techniques (activated carbon, activated carbon fiber, carbon mat filter etc.), as well as removing acid-base harmful chemicals by neutralization reaction.

열처리가 Al-Mg 코팅 강판의 내식성에 미치는 영향

정재훈(Jae-Hun Jung),양지훈(Ji-Hoon Yang),송민아(Min-A Song),김성환(Sung-Hwan Kim),정재인(Jae-In Jeong),이명훈(Myeong-Hoon Lee) 한국표면공학회 2014 한국표면공학회지 Vol.47 No.4

Double layer films which consisted of aluminum(Al) and magnesium(Mg) have been prepared by e-beam deposition. The structure, alloy phase, and corrosion resistance of the prepared films were investigated before and after heat treatment. The first (bottom) layer fixed with Al, and the thickness ratio between Al and Mg layers has been changed from 1 : 1 to 5 : 1, respectively. Total thickness of Al-Mg film was fixed at 3 μm. The cold-rolled steel sheet was used as a substrate. Heat treatment was fulfilled in an nitrogen atmosphere at the temperature of 400℃ for 2, 3 and 10 min. Surface morphology of as-deposited Al-Mg film having Mg top layer showed plate-like structure. The morphology was not changed even after heat treatment. However, cross-sectional morphology of Al-Mg films was drastically changed after heat treatment, especially for the samples heat treated for 10 min. The morphology of as-deposited films showed columnar structure, while featureless structure of the films appeared after heat treatment. The x-ray diffraction data for as-deposited Al-Mg films showed only pure Al and Mg peaks. However, Al-Mg alloy peaks such as Al3Mg2 and Al12Mg17 appeared after heat treatment of the films. It is believed that the formation of Al-Mg alloy phase affected the structure change of Al-Mg film. It was found that the corrosion resistance of Al-Mg film was increased after heat treatment.