실험적 급성 허혈성 신부전에서 Verapamil 이 혈중 Polyamine 동태에 미치는 영향

원동준(Dong Jun Won),권현민(Hyun Min Kwon),김용섭(Yong Seop Kim),구자룡(Ja Ryong Gu),권영주(Young Ju Kwon),조원용(Won Yong Cho),김형규(Hyung Kyu Kim) 대한내과학회 1991 대한내과학회지 Vol.40 No.6

N/A It has been proposd that calcium entry from an external medium increases intracellular free calcium to toxic levels during ischemic acute renal failure, and verapamil (ARF) has been suggested as the agentblocking calicium entry into renal cells and protecting renal function during ischemic injury. Polyamines, anorganic cations that play various roles in normal cellular proliferation and differentiation, accumulate in renal failare. Alsa it has been suggested tht the synthesis and metabolism of polyamine are influence by acute changes of the general condition, such as acute renal failure, and are mediated by a calcium influx into the cells. The study was designed to study the protective effects of systemic verapamil pretreatment on renal function and the influence on polyamine metabolism in experimental ischemic ARF in cats. For these purpose, the experimental animals were divided into 2 groups. While Group I (n=5) was an ischemic ARF model by renal artery clamping for 60 minutes, Group II (n=5) was ischemic ARF with systemic verapamil (5 ml/min/kg) pretreatment. The creatinine clearance and plasma and urinary polyamine were measured in each group before and after the renal artery clamp. The results were as follows: 1) Creatinine clearance before and after the renal artery clamp were 10.64±7.18 ml/min/kg and 2.09±1. 70 ml/min/kg in Group I, 4.47±3.38 ml min/kg and 0.60±0.79ml/min/kg in Group II, respectively, So creatinine clearance decreased more significantly in Group II campared with Group I. 2) Plasma polyamine increased after ischemia in Group I. In group I, plasma levels of putrescine, spermidine, and spermine before ischemia were 4.75±0.40 nmol/ml, 0.69±0.09 nmol/ml, and 0.83±0.63 nmol/ml, were elevated to 7.17±2.91 nmol/ml, 9.83±1.46 nmol/ ml, and 2.64±1.14nmol/ml after ischemia. But in Group II, the plasma level of polyamine was not changed, and especially, spermine decreased significantly from 0.83±0.27 before ischemia to 0.49±0.23 nmol/ml after ischenmine (p=0.033). 3) Urine polyamine excretion decreased after ischemia in Group I and Group II. In Group II, urinary excretion of spermidine and spermine before ischemia, 0.13±0.10 nmol/min and 0.17±0.13nmol/min, decreased after ischemia to 0.01±0.01nmol/min (p=0.019) and 0.032±0.26 nmol/min (p=0.0257). 4) In renal tissue, spermine content vas highest. In Group II, preischemic spermine were 397.20 nmol/g and increased to 646.66nmol/g after ischema, But there were no significant changes in the polyamine contents in Group II. From these data, it was suggested that systemic verapamil pretreatment exerts no protective effect on ischemic ARF. Plasma polyamines are elevated in ischemic ARF, and verapamil may protect these elevations.

Investigation on Delamination Characteristics of 2-Ply Clad Metals and Adhesive Joints for Aluminum/Stainless Steel via the Peel Test

Jun‑Hyung Sim,Yungeun Ha,Min‑Kyun Kim,Min‑Joong Kim,Young‑Rae Cho 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.2

Bonding properties are important for metallic multilayer composites (MMCs) comprising different materials or materialswith different mechanical properties. In this study, we fabricated 2-ply Al/stainless steel (STS) clad metals and Al/adhesive(adh)/STS joints. To manufacture samples with various mechanical properties, T6 heat treatment was performed on cladmetals, and adhesive joints of several thicknesses were prepared. For each sample, the bonding strength was characterizedvia a T-peel test and the results were analyzed using the peeling angle. For 2-ply Al/STS clad metals, the T6 heat treatmentresulted in opposite trends in the mechanical properties. The bonding strength of 2-ply Al/STS clad metals was affectedby the peeling angle, i.e., a small peeling angle provided a small bonding strength at the interface. However, for the 2-plyAl/adh/STS joints, the bonding strength of adhesives on metals depended on each adherend of the stress state. As the differencein mechanical properties between the two adherends increased, the difference in each peeling angle of Al and STSalso increased. The peeling angle of adherends reached a limiting value when the sample contacted the clamping jig head;therefore, a new term, apparent bonding strength (ABS), is necessary to differentiate this new strength from the bondingstrength obtained under non-contact conditions. We believe that the concept of peeling angle and ABS proposed herein willplay a crucial role in describing the delamination behavior and bonding strength of MMCs via the peel test.

간경변 환자에서 Oro-cecal Transit Time의 측정

원경준,이준,변유미,조민근,조주연,서정균,김영대,박찬국,김만우 朝鮮大學校 附設 醫學硏究所 2008 The Medical Journal of Chosun University Vol.33 No.2

Background: Neurotransmitter like substances in the gut have been proposed to contribute to the overall portal systemic encephalopathy (PSE). The source of the ammonia in patients with PSE is mainly the small bowel, as a result of the conversion of glutamine in the diet to glutamate and ammonia. PSE is highly responsive to changes in diet, to antibiotic therapy and to ingestion of nondigestible disaccharides such as lactulose. This study was performed to evaluate the relationship between PSE and oro-cecal transit time. In addition, performed to evaluate the effect of severity, cause, complications of liver cirrhosis on oro-cecal transit time. Methods: Between August 2006 and February 2007, 48 cirrhotic patients consecutively was enrolled in study their oro-cecal transit time after informed consent was obtained. A non-invasive hydrogen breath test was used to study oro-cecal transit time (OCTT). Result: The OCTT were delayed in cirrhotic patients with PSE compared without PSE (123.3 ± 42.7 min vs 170.0 ± 58.3 min, p<0.05). OCTT tended to prolongate further as the damage in the liver got worse, nevertheless the result was statistically meaningless (p<0.111). Neither presence of ascites or cause of PSE had any influence on gastrointestinal transit. Conclusions: Cirrhotic patients with PSE have more delayed OCTT than without PSE. Further research is needed to find out the relationship between OCTT and severity of liver cirrhosis.

흡연이 Gastric Emptying Time에 미치는 영향

조민구(Min Koo Cho),정순영(Sun Young chung),김소연(So Yon Kim),문희승(Mun Hee Seung),김진석(Jin Suk Kim),이석호(Suk Ho Lee),이권전(Gwon Jun Lee) 대한소화기학회 1990 대한소화기학회지 Vol.22 No.2

The effect of cigarette smoking on gastric emptying was examined in 25 healthy volunteers by means of Tc-sulfur colloid labeled-solid meal. The volunteers underwent GET measurement two times: before smoking and after smoking two cigarettes. Before smoking, the each average of GET T25% T50%, T75%, was 18 +- 5.2, 40 +- 6.7, 90 +- 18.4 min and after cigarette smoking the each average of GET T25%, T50%, 75% was 30 +- 8.3, 64 +- 12.6, 114 +- 7.0 min. We concluded that cigarette smoking significantly delayed gastric emptying of a solid meal (p< 0.05).

농업 부산물 바이오매스 특성에 따른 반탄화 공정 최적화: 1. 질량감소 예측 모델 개발

김석준 ( Seok Jun Kim ),오광철 ( Kwang Cheol Oh ),박선용 ( Sun Young Park ),조라훈 ( La Hoon Cho ),김민준 ( Min Jun Kim ),이충건 ( Chung Geon Lee ),정인선 ( In Seon Jeong ),전영광 ( Yeong Kwang Jeon ),김대현 ( Dae Hyun Kim ) 한국농업기계학회 2018 한국농업기계학회 학술발표논문집 Vol.23 No.2

본 연구에서는 국내에서 버려지고 있는 농업부산물의 에너지로서 이용 가능성이 분석되었다. 농업부산물 바이오매스는 화석연료와 동일하게 활용가능하며 지속적으로 생산되는 에너지원이다. 하지만 높은 수분 함량에 따른 보관문제, 화석연료와 비교하여 낮은 발열량등의 단점을 지니고 있어 전처리공정이 요구된다. 따라서 효율적인 활용을 위한 전처리 공정으로 반탄화가 선정되었다. 반탄화공정은 수분제거를 통해 에너지가 증가되어 저장·운송에 이점으로 인하여 최종적인 에너지 가치가 증대된다. 실험은 문헌탐색을 통한 반탄화공정 적용 가능 농업부산물(고추대)과 실험조건(200, 230, 270C, 10, 20, 30, 40 min)이 선정되었으며, 1차원 시뮬레이션을 통한 분석이 이루어졌다. 이때 반탄화 실험을 통하여 발생되는 질량감소량과 발열량 변화량은 높은 상관관계(r²=0.9528)를 가지고 있으며 본 연구에서는 반탄화공정의 질량감소량 예측 모델개발이 수행되었다. 질량감소량 분석을 위하여 열 중량 분석(Thermo Gravimetric Analyzer, TGA)이 수행되었으며 승온속도(5, 7.5, 15, 22.5, 30, 37.5°C min^-1)에 따른 반응속도상수가 도출되었다. 1차원 시뮬레이션 분석을 통하여 바이오매스 내부 온도를 예측하였으며 앞서 도출된 반응속도 상수를 이용하여 질량감소량이 예측되었다. 질량감소량 실험 및 시뮬레이션 결과 평균 r²=0.97로 상관관계를 나타내고 있으며 공정온도별 평균제곱근오차(Root Mean Square Error, RMSE)가 200°C-0.0165, 230°C-0.0191, 270°C-0.0207로 나타났다. 공정온도 증가에 따라 정확도가 감소되었으며, 이는 고온의 실험조건에서 발생되는 비응축가스와 온도변화에 의한 열분해 특성에 기인한 것으로 판단된다. 최종적으로 더 나아가서 질량감소 모델을 통한 발열량 예측을 위한 분석이 이루어져야한다.

온풍 조건에서 수분 탈락 정도에 따른 피부 분류 및 개선 방안에 대한 연구

권오선 ( Oh Sun Kwon ),강현종 ( Hyun Jong Kang ),한승민 ( Seung Min Han ),윤지선 ( Ji S Eon Yoon ),조웅희 ( Woong Hee Cho ),오주영 ( Joo Young Oh ),임준만 ( Jun Man Lim ),송영숙 ( Young Sook Song ),박선규 ( Sun Gyoo Park ) 대한화장품학회 2020 대한화장품학회지 Vol.46 No.2

피부를 탄력있고 부드럽게 하는 역할은 각질층에 존재하는 수분량에 의해 좌우된다. 피부 수분량은 냉온풍, 건조환경 등 다양한 환경 변화에 의해 영향을 받음이 알려져 있으나, 개인 피부 차이에 따른 피부수분량 변화와 회복 정도에 대해서는 많은 연구가 이루어 지지 않은 실정이다. 본 연구에서는 온풍 조건하에서 피시험자들의 피부 수분 탈락 및 회복 정도를 비교 평가하여 새로운 피부 타입을 제시하고, 온풍 조건에서 저하되는 피부 수분량을 개선 시켜주는 효능 물질을 개발하고자 하였다. 온풍 환경 조성을 위해, 건강한 피험자(남: 10 명, 여: 39 명, 25 세 - 63 세)의 전완부에 온풍(30 cm, 40 ℃, 6 m/s)을 30 min 간 피부에 노출시켜, 피부 수분량의 변화를 평가하였다. 26명(남: 4 명, 여: 22 명, 평균 연령: 42.7 ± 9.4)이 온풍 노출전에 비하여 온풍 노출 후 수분량이 유의하게 감소하며, 노출 후 30 min이 지나도 회복이 되지 않았다. 온풍노출 후 수분량이 떨어지는 피험자(여: 10 명)를 대상으로 보수력이 높은 크림을 3 주간 전완부에 적용한 이후 동일 온풍 조건하에서 피부 수분량을 측정한 결과, 노출 30 min 후 피부 수분량이 온풍 노출 전 수준으로 회복됨을 확인하였다. 본 연구를 통하여 피부는 건조 조건에서 쉽게 수분을 잃어버리는 피부(탈수형 피부)가 존재하는 것을 확인하였다. 이는 앞으로 화장품 개발을 보습 기능뿐만 아니라, 이러한 환경변화에 따른 피부수분이 쉽게 빠져나가는 피부(탈수형 피부)의 특성에 맞는 제품의 효능 개발이 필요함을 보여준다. Elasticity and softness of the skin depend on the level of moisture present in the stratum corneum, which is known to be affected by various environmental changes, such as cold and hot winds and dry environments. However, not many studies have been conducted on changes in skin moisture and the degree of recovery due to individual skin differences. In the present study, we aimed to investigate the effect of warm air heating on skin hydration levels and develop moisturizing formulas to improve lowered skin hydration levels. In order to deliver warm air heating condition, heating dryer (40 ℃, 6 m/s, 30 cm apart from forearm) was applied into inner forearm of healthy subjects (male: 10, female: 39, age: 25 - 63) Among 49 subjects, 26 subjects showed significantly lowered skin hydration levels until 30 min after warm air heating exposure (lowered group). In addition, moisturizing cream with high water holding capacity was applied to forearm of 10 subjects in lowered group for 3 weeks and skin hydration levels after warm air heating were significantly improved at the levels of before application of warm air heating. From this study, we found out that there is a skin type that skin hydration levels are significantly decreased under warm air heating condition (dehydrated skin) and this dehydrated skin can be improved by moisturizing formulas with high water holding capacity.

Soft-type trap-induced degradation of MoS₂ field effect transistors

Cho, Young-Hoon,Ryu, Min-Yeul,Lee, Kook Jin,Park, So Jeong,Choi, Jun Hee,Lee, Byung-Chul,Kim, Wungyeon,Kim, Gyu-Tae IOP 2018 Nanotechnology Vol.29 No.22

<P>The practical applicability of electronic devices is largely determined by the reliability of field effect transistors (FETs), necessitating constant searches for new and better-performing semiconductors. We investigated the stress-induced degradation of MoS<SUB>2</SUB> multilayer FETs, revealing a steady decrease of drain current by 56% from the initial value after 30 min. The drain current recovers to the initial state when the transistor is completely turned off, indicating the roles of soft-traps in the apparent degradation. The noise current power spectrum follows the model of carrier number fluctuation–correlated mobility fluctuation (CNF–CMF) regardless of stress time. However, the reduction of the drain current was well fitted to the increase of the trap density based on the CNF–CMF model, attributing the presence of the soft-type traps of dielectric oxides to the degradation of the MoS<SUB>2</SUB> FETs.</P>

생체분해성 고분자를 이용한 사시수술용 제형개발 및 효용성에 대한 연구

민병무,김용백,김승영,김창식,박근성,길숙종,조항진,이성복,노승무,송규상,강대영,조준식,양준묵,정경수,최선웅,이진호,김학용,인현빈 충남대학교 의과대학 지역사회의학연구소 1998 충남의대잡지 Vol.25 No.1

A new device, muscle clamping system was developed to facilitate exact quatifying technique A strabismus surgery, and reduce the risk of complications. The device is composed of a lower fixing body with three jaws and an upper supporting body. They are used to clip an extraocular muscle and fix it to the sclera with a single bite. Superior rectus recession on 16 rabbit eyes were performed with this new device. Conjunctival injection, muscle adhesion strength, and light microscopic findings were examined at 1, 2, 4 and 8 weeks postoperatively. The Conjunctival injection were minimal, adhesion power ranged from 420 to 600 gram gravity, which is sufficient in withstand the normal pull of human extraocular muscle. In microscopic exam, some Inflammatory cells and fibrosis were found. The new device was technically easy, fast, and accurate, so it may be useful in stabismus surgery.

제지용 도공안료의 표면개질에 의한 도공지 물성과 인쇄적성에 관한 연구(Ⅱ)

민동진,이희명,조준형,이용규,김용식 한국공업화학회 2004 공업화학 Vol.15 No.1

도공지의 품질향상을 위하여 도공용 무기안료의 제법개선, 도공액 특성 변화, 도공안료의 설계, 도공지 제조의 조업성 등 다양한 측면에서의 연구들이 진행되고 있다. 본 연구는 표면개질한 도공안료와 혼합처리한 도공안료를 용하여 도공지의 물성 및 인쇄적성을 비교하였다. 도공액 배합 시도공액의 유동특성과 인쇄특성에 영향을 줄 수 있는 여러 인자들을 일정하게 고정하였고 도공안료의 표면개질 유무에 따른 인쇄특성 변화를 조사하였다. 도공지의 표면은 SEM으로 측정하여 표면개질 효율을 조사하였다. 도공액의 물성뿐만 아니라 도공지의 물성 및 인쇄적성에 대한 비교ㆍ평가를 실시하였다. 또한 배합조건을 달리하여 인쇄적성의 효율성을 평가하였다. To improve the quality of coating paper, many areas, such as the manufacturing process of inorganic pigment for the coating, the property change of coating color. the surface design of coating pigment and the productivity of coated paper, were studied. In this study the physical properties and printability of coated paper were compared with the coating pigment to modify the surface of large particle and the coating pigment to mix together the large and small particles. After the coating color was mixed under the same conditions in order that the coating color has the same rheological property printability, the printability change caused by the surface modification of coating color was investigated. With the surface SEM of coated paper. the efficiency of the surface modification of coating pigment was investigated. The physical property and printability of coating paper, in addition to the physical properties of coating color. were compared and evaluated. Also. the efficiency of printability was evaluated, changing the mixing condition

프로축구 선수들의 포지션별 유산소성 파워능력과 슬관절 등속성 근 기능의 특성

조현철,김준호,강민철,김종규 龍仁大學校 體育科學硏究所 2004 體育科學硏究論叢 Vol.14 No.1

The purpose this study was to investigate the aerobic power and isokinetic muscular function of knee joint for korea the pro-soccer players in field position. Data were obtained from thirty one pro-soccer players. They didn't have any medical problem. They performed exercise stress test and isokinetic muscular function on treadmill and Isomed 2000. The assessment of cardiorespiratory and isokinetic muscular function were VO2max, Maximal heart, ATVO2, AT heart rate, Total Work, Average Work, Maximum Torque, Maximum Work and Flex/Ext. A two-way analysis of variance with repeated measures(two-way(2x4)RM ANOVA) was used to compare group and field position differences aerobic power and isokinetic muscular function. A Tukey post hoc test was used when significant mean differences were observed. Statistical significance was accepted as p<O.05. Aerobic power do not showed any significant difference among in field position. Hamstring muscle power was significantly higher in Forward and Middle field than Defense and Goal keeper. Muscular endurance was higher Defense and Goal keeper than Forward and Middle field. Based on the facts that we have discussed, aerobic and anaerobic power in field position do not showed any difference. However, isokinetic muscular function was significant difference in field position. Ratios of conventional and functional for isokinetic Hamsting: Quadriceps muscle strength in soccer player for prediction and decision injures, it is thought that more researches on it should be required.