전남산 젓갈류의 유리아미노산 조성

허남칠,김선민,박은령,박평심,김경수,이명렬 조선대학교 기초과학연구소 1998 自然科學硏究 Vol.21 No.1

This study was designed to investigate the free amino acid compositions of salt-fermented fish products in the markets of Chonnam area. The results were as follows : The free amino acid compositions of salt-fermented fish products had varying figures according to the species of raw materials, that is, lysine and leucine were relatively abundant in Myul-chi jeot (salt-fermented anchovy), arginine inSae-woo jeot (salt-fermented small shrimp), glutamic acid inJa-oi jeot (salt-fermented small shrimp). lysine, arginine, alanine and phenylalanine in To-h jeot (salt-fermented trout), etc. Essential amino acid contents were contained 31.02%∼83.46% of total amino acids in all sample, and lysine and leucine were most abundant among essential amino acids. Especially tryptophan was the richest in Cham-jo-gae jeot, phenylalanine in To-ha jeot, Kal-chi-nae-jang jeot and Song-eo jeot in other essential amino acids. because the degree of protein degradation wouldl be influenced on fermentation periods, salt-concentration, fermentation temperature, etc, we expected more systemic research by some varied conditions and the developed analytical techniques on the salt-fermented fish products should be followed.

당뇨병 환자에서 혈장 Thrombin-Antithrombin Ⅲ 및 Plasmin-α_2-Plasmin Inhibitor 복합체의 임상적 의의

김경욱,김은숙,정상수,윤수지,박우일,이준희,남수연,안철우,문병수,김경래,차봉수,송영득,임승길,이현철,허갑범 대한당뇨병학회 2002 Diabetes and Metabolism Journal Vol.25 No.5

연구배경:당뇨병 환자에서 혈액응고 및 섬유소용해 체계의 이상경향이 있어 그 결과로 여러 혈관합병증의 발생위험이 높다는 사실은 널리 알려져 있다. 그 기전은 아직 확실히 밝혀지지 않았으나, 고혈당으로 인한 혈장 단백질들의 비효소성 당화작용이나 산화성 스트레스로 인한 유리 라티칼 작용으로 응고항진이나 섬유소용해 활성의 저하를 유발하는 것으로 생각되고 있다. 최근 응고 및 용해인자와 그 억제자의 복합체들의 증가가 이 상태를 비교적 예민하게 반영한다고 알려져 있다. 방법:본 연구에서는 당뇨병 환자 101명과 정상 대조군 20명에서 혈장내 thrombin­antithrombin complex(TAT)와 plasmin­α₂­plasmin inhibitor complex(PIC)를 측정하여 비교하고, 당뇨병 환자에서 미세혈관 합병증과 대혈관합병증의 유무에 따른 차이와, 이미 혈관 질환의 위험인자로 알려져 있는 인자들간의 상관성을 알아보고자 하였다. 결과:1. 환자의 분포를 살펴보면 혈관합병증이 있는 군은 85명, 혈관합병증이 없는 군은 16명이었고, 평균연령은 각각 57.9±14.1세, 49.9±16.6세로 혈관 합병증이 있는 군에서 더 나이가 많았고, 체질량지수는 23.2±3.4㎏/㎡, 24.1±3.4㎏/㎡로 두 군간 유의한 차이는 없었다. 또 두 군간의 혈압 및 HbA1c, 공복혈당 및 인슐린과 C­peptide, 총 콜레스테롤, 중성지방, HDL­콜레스테롤, Lp⒜는 유의한 차이가 없었고, 미세혈관합병증이 있는 군에서 당뇨병의 유병기간이 길었다. 2. TAT 및 PIC의 농도는 정상 대조군에서는 2.8±1.2 ng/mL, 240.4±69.7 ng/mL이었고, 당뇨병 환자군에서는 9.5±22.6 ng/mL, 472.2±258.7 ng/mL이었다. TAT와 PIC 모두 당뇨병 환자군에서 정상 대조군에 비해 유의하게 증가되어 있었고(p<0.001), TAT/PIC ratio는 두 군간 차이가 없었다. 3. 당뇨병 환자의 혈관합병증에 따른 TAT 및 PIC, fibrinogen 농도는 합병증이 없는 군은 각각 4.1±2.4ng/mL, 362.2±272.0ng/mL, 322.7±102.4mg/mL으로 PIC와 fibrinogen의 증가를 보였으나, 연령을 보정한 후에는 통계학적 유의성은 없었다. 또 대혈관 합병증군에서는 각각 6.0±4.9 ng/mL, 507.4±321.6 ng/mL, 427.1±194.7 mg/dL이었으며 미세·대혈관 합병증군에서는 10.4±6.4 ng/mL, 484.8±269.7 ng/mL, 388.4±132.4 mg/dL으로 TAT의 증가를 보였으나 역시 연령을 보정한 후에는 통계학적 유의성은 없었다. 4. 미세혈관합병증군에서 HbA1c(>8%)가 높은 군의 PIC 농도가 유의하게 높았고(p=0.049), 대혈관합병증군에서 HbA1c(>8%)가 높은 군의 총 콜레스테롤 농도가 유의하게 높았다(p=0.042). 5. 총 당뇨병 환자군에서 PIC는 fibrinogen과 HbA1c와 양의 상관관계를, BMI와 음의 상관관계를 보였으며(r=0.47, 0.31,-0.25), 혈관 합병증이 없는 당뇨병 환자군에서만 TAT는 HbA1c와 양의 상관관계를 보였다(r=0.67). 결론:이상의 결과에서 혈장 TAT 및 PIC 농도는 당뇨병 환자에서 정상 대조군에 비해 의미있게 증가되어 있었고, 당뇨병 환자군에서는 연령의 증가와 유병기간이 혈액응고항진 및 용해의 장애에 큰 역할을 함을 알 수 있었으며, 총 당뇨병 환자군에 PIC와 HbA1c와 양의 상관관계를, BMI와 음의 상관관계를 보였으며 혈관 합병증이 없는 당뇨병 환자군에서만 TAT는 HbA1c와 양의 상관관계를 보였다. 따라서 당뇨병 환자에서 혈액응고 및 용해의 장애가 동반되어 있다고 볼 수 있으며, 혈장 TAT 및 PIC는 혈관합병증으로의 진행을 예측하는 지표로서 유용하리라 생각된다. 또 혈당조절정도와 상관성이 있으므로 혈당조절후에 추적검사를 시행하여 합병증의 예방이 가능한지 추후 연구가 필요하리라 생각된다. Background : Abnormality of coagulation and fibrinolystic system is known as a predisposing factor of vascular complication in diabetes. Although the pathogenesis is not well known, non-enzymatic glycation reaction and the increase in production of free radicals due to an increased oxidative stress may be linked to the hypercoagulibility and hypofibrinolytic activity. As indices of abnormality in coagulation and firinolysis in peripheral blood, plasma thrombin-antithrombin Ⅲ complex (TAT) and plasmin-α_2-plasmin inhibitor complex (PIC) were measured. The purpose of this study was to clarify whether hypercoagulability exists in diabetic patients with or without vascular complication. Methods : In our study, we measured plasma thrombin-antithrombin Ⅲ compelx (TAT) and plasmin-α_2-plasmin inhibit or complex (PIC) in 101 diabetic subjects and 20 controls. Comparing TAT and PIC levels in diabetic microvascular complication group, diabetic macrovascular complication group and controls, we examined correlation between risk factors associated with diabetic vascular complication. Results : 1. The group with diabetic vascular complication was older than group without complication. There was no significant difference in BMI, blood pressure, HbA_ic, blood sugar level, insulin, C-peptide, serum creatinine, total cholesterol, triglyceride, HDL-cholesterol, Lp (a) between two groups. The group with diabetic microvascular complication had longer duration of diabetes. 2. Concentration of TAT and PIC were 2.8±1.2 ng/ mL, 240.4±69.7 ng/ mL in controls and 9.5±22.6 ng/ mL, 472.2±258.7 ng/ mL in diabetic patients, respectively. TAT and PIC were significantly higher in diabetic patients than in control (p<0.001). But TAT/PIC ratio was no significant difference between two groups. 3. In diabetic patients, concentration of TAT and PIC and fibrinogen were respectively 4.1±2.4 ng/ mL, 362.2±272.0 ng/ mL, 322.7±102.4 mg/ dL in group without vascular complication and 5.3±4.1 ng/ mL, 529.5±258.7 ng/ mL, 374.9±106.2 mg/ dL in group with microvascular complication, which group had increase in PIC and Fibrinogen but no significance after correction of age. Concentration of TAT and PIC and Fibrinogen were 60.±4.9 ng/ mL, 507.4±321.6 ng/ mL, 427.1±194.7 mg/ dL in macrovascular complication, and 10.4±6.7 mg/ mL, 484.8±269.7 ng/ mL, 388.4±132.4 mg/ dL in combined vascular complication which group showed increase of TAT but also had no significant increase after correction of age. 4. In diabetic microvascular complication patients, group of high HbA_1c (>8%) (p=0.049) had significant high PIC concentration. In diabetic macrovascular complication patients, group of high HbA_1c (>8%) (p=0.042) had significant high total cholesterol concentration. 5. In all diabetic patients, PIC was positively correlated with fibrinogen and HbA_1c and negatively correlated BMI (r=0.47, 0.31, -0.25). Only in daibetic patients without angiopathy, TAT was positively correlated with HbA_1c (r=0.67). Conclusion : In this study, plasma TAT and PIC concentration significantly increased in diabetic patients compared with controls, and PIC was increased in group with microvascular complication, TAT were increased in group with combined micro macrovascular complication. However, there was no significance relationship existed when correctinf for age. PIC was correlated with HbA_1c. TAT was correlated with HbA_1c only in the group without angiopathy. Abnormality of coagulation and fibrinolysis were combined in diabetes, plasma TAT and PIC can be used as an index of vascular complication. Also we found the correlation with the degree of the blood glucose control. Therefore we need follow up study for the possibility of prevention of vascular complication after controlling the blood glucose to age-matched patients (J Kor Diaabetes Asso 25:354~363, 2001).

Finite Element Analysis of Hydrogen Concentration for Blister Growth Estimation of CANDU Pressure Tube

Huh, Nam Su,Kim, Yun Jae,Kim, Young Jin,Kim, Young Suk,Cheong, Yong Moo Trans Tech Publications, Ltd. 2005 Key Engineering Materials Vol.297 No.-

복합하중이 작용하는 원주방향 관통균열이 존재하는 배관의 새로운 J-적분 및 COD 계산식

허남수(Nam-Su Huh),김윤재(Yun-Jae Kim),김영진(Young-Jin Kim),박치용(Chi-Yong Park),정대율(Dae-Yul Chung) 대한기계학회 2001 대한기계학회 춘추학술대회 Vol.2001 No.3

In order to apply the Leak-Before-Break (LBB) concept to nuclear piping, accurate estimation of J-integral and crack opening displacement (COD) is essential for complex loading, such as combined tension and bending. This paper proposes a new engineering method to estimate J-integral and the COD for circumferential through-wall cracked pipes subject to combined tension and bending loading. The proposed method to estimate the COD is validated against three published pipe test data, generated from a monotonically increasing bending load with a constant internal pressure, which shows excellent agreements.

비만증에서 Pyridostigmine , Acipimox 투여에 따른 성장호르몬 방출호르몬 자극에 의한 성장호르몬의 분비반응

남수연(Su Youn Nam),이은직(Eun Jig Lee),남문석(Moon Suk Nam),조재화(Jae Hwa Cho),김인재(In Jai Kim),김정환(Jung Hwan Kim),김경래(Kyung Rae Kim),임승길(Sung Kil Lim),이현철(Hyun Chul Lee),허갑범(Kap Bum Huh) 대한내과학회 1996 대한내과학회지 Vol.50 No.3

Objectives: Obesity is associated with an impairment of normal GH secretion and blunted responses to all stimuli. Recent reports suggests that increased somatostatinergic activity is the basis for the GH derangement of obesity. However, the basic mechanism of this alteration is till being debated, The high plasma free fatty acid(FFA) is frequently observed in obesity. FFA participates in the regulation of pituitary GH secretion. To determine whether the derangement of GH secretion in obesity is associated with a high plasma FFa levels. Methods: Several tests with GH-releasing hormone(GHRH) with or without pyridostigmine (PYR) and acipimox(ACX), antilipolytic agents able to decrease FFA, were undertaken in both six obese and seven normal control subjects. Results: 1) In obese subjects, the GH response(mean peak±SEM:8.0±1.1 μg/L) to GHRH-(1-29)(1 μg/kg, iv) was significantly blunted when compared to normal controls(25.7±1.8 μg/L; p<0.05). 2) After PYR(120 mg), the response to GHRH only, but remained significantly reduce compared to controls treated with PYR plus GHRH 943.2±6.0 μg/L; p<0.05). 3) Basal FFA levels were higher than those of normal controls(p<0.05), ACX(500 mg) decreased FFA levels in both obese and normal subjects; the lowest FFA levels at 0.15 min were similar to those of normal cantrols, ACX also potentiated GHRH stimulated GH response in both obese and normal subjects. The GH responses potentiated by ACX in obesity(22.7±5.5 μg/L) were similar with those of PYR plus GHRHub ibese sybhects and GHRH in normal controls, but lower than control treated with ACX plus GHRH in normal controls, but lower than control treated with ACX plus GHBH(50.8±6.7 μg/L; p<0.05). 4) After the conbined pretreatment with ACX and PYR, GH responses in obesity(44.1±6.0 μg/LO were significantly higher than those to GHRH test, PYR plus GHRH, and ACX plus GHRH in normal controls. However their enhanced GH responses reduced compared to the control with ACX plus PYR plus GHRH(64.9±4.5 μg/L p<0.05). Conclusion: Our results are in agreement with hypothalamic hypothesis; an increase in somatostatinergic tone is responsible for the blunted GH response to GHRH in obesity. In addition, the demonstation that the decreased FFa levels induced by ACX potentiate the somatotrope responsiveness, likely acting at pituitary level, suggests that high plasma FFA levels play an important role in GH responsiveness in obesity, although other factors might also be involved in GH derangements.

유한요소해석을 이용한 지르코늄 압력관의 블리스터 생성 및 성장 해석

허남수(Nam-Su Huh),김윤재(Yun-Jae Kim),김영진(Young-Jin Kim),김영석(Young-Seok Kim),정용무(Yong-Moo Cheong) 대한기계학회 2003 대한기계학회 춘추학술대회 Vol.2003 No.11

The pressure tubes, which contain high temperature heavy water and fuel, are within the core of a CANDU<br/> nuclear reactor, and are thus subjected to high stresses, temperature gradient, and neutron flux. Further, it is<br/> well known that pressure tubes of cold-worked Zr-2.5Nb materials result in hydrogen diffusion, which create<br/> fully-hydrided regions (frequently called Blister). Thus a proper investigation of hydrogen diffusion within<br/> zirconium-alloy nuclear components, such as CANDU pressure tube and fuel channels is essential to predict<br/> the structural integrity of these components. In this respect, this paper presents numerical investigation of<br/> hydrogen diffusion to quantify the hydrogen concentration for blister growth of CANDU pressure tube. For<br/> this purpose, coupled temperature-hydrogen diffusion analyses are performed by means of two-dimensional<br/> finite element analysis. Comparison of predicted temperature field and blister with published test data shows<br/> good agreement.

유한요소해석을 이용한 노즐 이종금속용접부의 용접잔류응력 예측

허남수(Nam-Su Huh),김종욱(Jong-Wook Kim),최순(Suhn Choi),김태완(Tae-Wan Kim) 대한기계학회 2008 대한기계학회 춘추학술대회 Vol.2008 No.11

The primary water stress corrosion cracking (PWSCC) of dissimilar metal weld based on Alloy 82/182 is one of major issues in material degradation of nuclear components. It is well known that the crack initiation and growth due to PWSCC is influenced by material’s susceptibility to PWSCC and distribution of welding residual stress. Therefore, modeling the welding residual stress is of interest in understanding crack formation and growth in dissimilar metal weld. Currently in Korea, a numerical round robin study is undertaken to provide guidance on the welding residual stress analysis of dissimilar metal weld. As a part of this effort, the present paper investigates distribution of welding resisual stress of a ferritic low alloy steel nozzle with dissimilar metal weld using Alloy 82/182. Two-dimensional thermo-mechanical finite element analyses are carried out to simulate multi-pass welding process on the basis of the detailed design and fabrication data. The present results are compared with those from other participants, and more works incorporating physical measurements are going to be performed to quantify the uncertainties relating to modelling assumptions.

내압에 의한 원주응력이 관통균열 배관의 J-적분 및 COD 계산에 미치는 영향의 정략적 해석

허남수(Nam-Su Huh),김윤재(Yun-Jae Kim),김영진(Young-Jin Kim) 대한기계학회 2001 대한기계학회 춘추학술대회 Vol.2001 No.8

This paper provides engineering J-integral and crack opening displacement (COD) estimation equations for through-wall cracked pipes under internal pressure and under combined internal pressure and bending. Based on selected 3-D finite element calculations for the through-wall cracked pipes under internal pressure using the idealized power law materials, the elastic and plastic influence functions for fully plastic J-integral and COD solutions are found as a function of the normalized crack length and the mean radius-to-thickness ratio. These developed GE/EPRI-type solutions are then re-formulated based on the enhanced reference stress method. Such re-formulation not only provides simpler equations for J-integral and COD estimations, but also can be easily extended to combined internal pressure and bending. The proposed equations are compared with elastic-plastic finite element results using actual stress-strain data, which shows overall excellent agreement.

파단전누설 해석 및 균열거동 평가를 위한 축방향 경사관통균열의 탄성 응력확대계수 및 균열열림변위

허남수(Nam-Su Huh),심도준(Do-Jun Shim),최순(Suhn Choi),박근배(Keun-Bae Park) 대한기계학회 2008 대한기계학회 춘추학술대회 Vol.2008 No.11

This paper proposes elastic stress intensity factors and crack opening displacements (CODs) for a slanted axial through-wall cracked cylinder under an internal pressure based on detailed 3-dimensional (3-D) elastic finite element (FE) analyses. Based on the elastic FE results, the stress intensity factors along the crack front and CODs through the thickness at the center of the crack were provided. These values were also tabulated for three selected points, i.e., the inner and outer surfaces and at the mid-thickness. The present results can be used to evaluate the crack growth rate and leak rate of a slanted axial through-wall crack due to stress corrosion cracking and fatigue. Moreover, the present results can be used to perform a detailed Leak-Before-Break analysis considering more realistic crack shape development.

탄성 유한요소해석을 이용한 동일 평면상에 존재하는 다중 표면균열의 균열상호작용 평가

허남수(Nam-Su Huh),김종민(Jong-Min Kim),최순(Suhn Choi),박근배(Keun-Bae Park),최재붕(Jae-Boong Choi),김영진(Young-Jin Kim) 대한기계학회 2008 대한기계학회 춘추학술대회 Vol.2008 No.5

The crack-tip stress fields and fracture mechanics assessment parameters, such as the elastic stress intensity factor and the elastic-plastic J-integral, for a surface crack can be significantly affected by adjacent cracks. Such a crack interaction effect due to multiple cracks can magnify the fracture mechanics assessment parameters. There are many factors to be considered, for instance the relative distance between adjacent cracks, crack shape and loading condition, to quantify a crack interaction effect on the fracture mechanics assessment parameters. Thus, the current guidance on a crack interaction effect (crack combination rule), including ASME Sec. XI, BS7910, British Energy R6 and API RP579, provide different rules for combining multiple surface cracks into a single surface crack. The present paper investigates a crack interaction effect by evaluating the elastic stress intensity factor of adjacent surface cracks in a plate along the crack front through detailed 3-dimensional elastic finite element analyses. The effects of the geometric parameters, the relative distance between cracks and the crack shape, on the stress intensity factor are systematically investigated. As for the loading condition, only axial tension is considered. Based on the elastic finite element results, the acceptability of the crack combination rules provided in the existing guidance was investigated, and the relevant recommendations on a crack interaction for in-plane surface cracks in a plate were discussed.