Dynamic Young's Modulus and Internal Friction in Polycrystalline Copper

Kang, Chang-Seog,Chang, Si-Young,Hong, Sung-Kil 대한금속재료학회 2003 METALS AND MATERIALS International Vol.9 No.5

An attempt has been made to measure the temperature dependence of dynamic Young's modulus together with the related variation of internal friction in polycrystalline copper. A mechanical spectroscopy study was employed using a standard servo hydraulic fatigue testing machine equipped with a scanning laser extensometer. Dynamic Young's modulus and internal friction were measured over a temperature range of 298 to 873 K at very low frequencies of 0.1, 0.05, and 0.01 Hz. One internal friction peak was observed over the ranges 450 to 700 K, together with marked decreases in the dynamic Young's modulus in the same temperature range. From a quantitative analysis of the experimental data with the relaxation strength, relaxation time, and activation energy, it is concluded that the peak phenomenon is due to grain-boundary sliding relaxation.

THE WORLD OF CREATIVE WRITING : Centering Around Lyrics Written by Son Kil-Yong

Son, Kil Young 서경대학교 1982 論文集 Vol.10 No.-

진공열간가압성형 (VHP) 법 및 압출로 제조한 SiCp/Al 및 SiCp/2024Al 복합재료의 동적탄성계수와 감쇄능 (내부마찰) : 금속기 복합재료의 동적탄성계수 및 감쇄능 측정

김영만,조기현,이경민,홍성길 대한금속재료학회(대한금속학회) 1999 대한금속·재료학회지 Vol.37 No.9

To shorten the processes of MMC fabrication, a number of techniques are being studied. In this study, a new process for MMC's fabrication was developed utilizing vacuum hot pressing and subsequent extrusion. MMC's with pure Al and 2024Al matrices reinforced with various volume fractions of SiC particulates were produced at 400℃ by vacuum hot pressing(VHP), followed by direct extrusion with extrusion ratios of 10:1 at 480℃ at constant ram speed of 2㎜/sec. The effects of extrusion pressure and relative density according to the volume fractions of the reinforcement were compared with the resultant metallurgical microstructures. Young's moduli of the manufactured composites were measured by the sonic resonance method, damping capacity by free decay method. Measured Young's moduli of the composites at room temperature were compared with the predictions based on Rule of Mixtures, Halpin-Tsai and Mean-field models. Measured Young's moduli of the composites are in good agreement with the predictions based on Mean-field model. The composites reinforced with finer particles showed higher damping capacity under the same amount of SiC reinforcement.

당뇨병성 다발성 신경병증에 대한 Thioctic acid의 유효성 및 안정성에 관한 연구

박철영,김영설,오승준,우정택,김성운,양인명,김진우,최영길 대한당뇨병학회 2001 임상당뇨병 Vol.2 No.1

연구배경: 당뇨병성 신경병증은 당뇨병 환자에서 흔히 나타나는 합병증으로서 임상 증상은 가볍거나 없을 수도 있지만 많은 경우에 통증, 작열감, 이감각증이나 무감각증 등의 증상을 동반하지만, 이에 대한 명확한 기전이나 뚜렷한 치료방법이 없었다. 최근에 신경세포내 산화성 스트레스의 증가로 신경세포의 손상이 발생된다는 기전이 주목을 받으면서, 당뇨병성 신경병증 환자에게 항산화제인 thiotic acid를 사용하여 좋은 효과를 관찰한 논문들이 발표되었다. 이에 저자들은 한국의 당뇨병성 다발성 신경병증 환자에서 thiotic acid를 경구 투여 후에 신경병증에 의한 효과 및 안정성을 평가하였다. 방법: 모든 대상 환자에게 Thioctic acid 600㎎ 을 1일 1회 아침 식전 30분에 8주간 투여하여 당뇨병성 다발성 신경병증에 대한 TSS의 개선여부에 대한 임상적 유효성 및 이상반응, 내약성, 실험실적 지표의 변화를 통한 안정성을 관찰하였다. 결과: 치료시작 전에 관찰한 환자가 호소하는 증상은 통증이 가장 많았으며 무감각, 작열감, 이상감각 순의 빈도를 보였다. 통증, 작열감, 이감각증, 무감각증의 평균 TSS는 1차 방문시 5.8± 1.8, 2차방문시는 4.4±1.7, 3차 방문시는 3.1±1.1로 사용기판에 따라 통계학적으로 유의한 증상의 호전이 있었다. 또한 TSS의 개선 뿐만 아니라 통증, 작열감, 이감각증 및 무감각증 각각의 증상도 치료전과 치료 4주 후 및 치료 8주 후를 비교했을 때 통계학적으로 유의한 증상의 호전이 있었다. TSS가 1차 방문 시와 비교했을 때 3차 방문시에 30% 이상 개선되었을 때(1차 방문시에 TSS 4인 환자는 2점 이상 개선되었을때) 임상적으로 의미가 있는 반응으로 간주하고 계산한 반응률은 71.3%였다. 결론: 당뇨병성 다발성 신경병중 환자에 대해 항 산화제인 thioctic acid 600㎎ 경구 투여요법은 당뇨병성 신경병증의 증상완화에 유용하며, 안전한 것으로 사료된다. Background: The study was peformed to evaluate the efficacy and safety of oral treatment with the antioxidant α-lipoic acid (Thioctcid??) in diabetic patients with peripheral polyneuropathy. Methods: Thioctacid?? 600㎎ was orally administered once a day for 8 weeks in 61 diabetic patients with peripheral polyneuropathy. Neuropathic symptom(pain, burning, paresthesia, and numbness) were scored before, and of 4 and 8 weeks after treatment. In addition, neuropathy by the physician and patients at the end of treatment. The primary endpoint was the response role after 8 weeks treatment, defined as an improvement in the total symptom score of at least more than 30%. Results: Efficacy was evaluated among forty-four patients who had completely the study according to the protocol and safety was evaluated among all of 61 patients who had taken the study medication. The response rate after 8 weeks was 77.3%. The total symptom score was significantly decreased of 4-week, and further decreased of 8-week. All the individual scores for neuropathic symptom were also significantly reduced of 4-week and further decreased at 8-week. Conclusion: These finding indicate that oral treatment with thioctacid?? at a dose of 600㎎/day for 8 weeks will improve peripheral polyneuropathy in diabetic patients, without causing any serious adverse events.

소아청소년 크리닉을 내원한 소아외래 환자에 관한 임상적 고찰

이영식,이길홍 중앙대부설한국의과학연구소 1991 한국의과학 Vol.23 No.4

포도당과 이소프로테레놀에 의한 시상하부의 소마토스타틴 분비가 갑상선자극호르몬방출호르몬에 의한 갑상선자극호르몬에 미치는 효과

박철영,양인명,오승준,김덕윤,우정택,김성운,김진우,김영설,최영길 대한내분비학회 2000 Endocrinology and metabolism Vol.15 No.4·5

유산균들의 콜레스테를 저하성, 내산성, 내담즙성, 항생제 내성 비교

박소영,고영태,정후길,양진오,정현서,김영배,지근억 한국미생물생명공학회 ( 구 한국산업미생물학회 ) 1996 한국미생물·생명공학회지 Vol.24 No.3

기능성 요구르트의 제조에 사용되는 유산균은 인체에 유익한 생리활성과 우수한 생존능력을 보유하고 있는 것이 바람직하다. 본 연구에서는 다양한 유산균주의 산과 담즙 및 항생제에 대한 내성을 조사하였으며 in vitro에서 콜레스테롤 저하능을 조사하였다. In vitro에서 콜레스테롤 저하능이 우수한 13균주를 선발하여 이들의 동결건조 분말을 고 콜레스테롤 식이의 실험쥐에 투여하였다. 그 결과 8균주는 비 투여구보다 유의적으로 18.3~27.3%의 콜레스테롤 저하능을 나타냈다(P≤0.05). 이들 중에서 Bifidobacterium infantis AM-220, Lactobacillus AM-245, Streptococcus MA-1의 3균주를 이용하여 요구르트를 제조한 후 동결건조 분말을 이용하여 급여실험을 수행한 결과, 총 콜레스테롤과 LDL 함량이 유의적으로 감소하는 것으로 나타났다. For a probiotic yoghurt it is desirable to utilize lactic acid bacteria with a high survival rate and beneficial function to human beings. We have examined a variety of lactic acid bacteria to assess the acid and bile tolerance and antibiotic resistance. In addition, an in vitro culture experiment was performed to evaluate their ability to reduce cholesterol levels in the growth medium. Thirteen strains were selected from in vitro cholesterol assays and fed to Sprague-Dawley rats with a high-cholesterol diet. Among the 13 strains tested, 8 strains were shown to reduce serum cholesterol levels significantly after 24 days of administration in vivo. Rats were fed lyophilized yoghurt powder fermented with a combination of 3 selected strains: Bifidobacterium infantis AM-220, Lactobacillus AM-245, and Streptococcus MA-1. The levels of total cholesterol and low density lipoprotein were significantly lower (p≤0.05) in rats fed the yoghurt powder compared with control group. These studies suggest that yoghurt fermented with appropriately selected lactic acid bacteria may have a anticholesterolemic effect.

Multiple myeloma 환자에서 Bortezomib치료 후 발생한 마비성 장폐색증 1례

김준영,이원식,손창학,박성길,진한영,박석주,조영완,정은욱,강명주,박정하,주영돈 인제대학교 2006 仁濟醫學 Vol.27 No.-

Bortezomib is the first clinically available proteasome inhibitor that is clinically effective in the treatment of multiple myeloma. A proteasome inhibitor acts through multiple mechanisms to arrest tumor growth, tumor spread, and angiogenesis. The main adverse effects of bortezomib are gastrointestinal symptoms, cytopenia, fatigue, and peripheral neuropathy. To date, severe paralytic ileus has not been reported as a toxic effect of bortezomib treatment in multiple myeloma. Bortezomib is a novel agent that has only been used clinically for 30 months, so a need exists to further evaluate its toxicity. We report a case of grade Ⅲ (NCI CTCAE v3.0) or grade Ⅳ(SWOG toxicity criteria) paralytic ileus in a 65-year-old man with relapsed multiple myeloma who underwent one cycle of single-agent bortezomib treatment scheduled in a 21-day cycle (1.3 mg/㎥ as a single i.v. bolus on days 1, 4, 8, and 11).

인터넷 중독 청소년들의 정신병리 및 대처 방식

안영균(Young Kyun Ahn),신영철(Young Chul Shin),고복자(Bok Ja Koh),심진현(Jin Hyun Shim),김범조(Bum Jo Kim),이승민(Seung Min Lee),이길홍(Kil Hong Lee) 한국중독정신의학회 2005 중독정신의학 Vol.9 No.1

This study was conducted to investigate the differences in psychopathology and coping strategies among internet addictors, over users and non addictors in high school students. Subjects were 273 high school students in Seoul city. Self rating questionnaires included demographic data, Young’s Internet Addiction Scale, SCL-90-R, Beck Depression Inventory, Spielberger State-Trait Anxiety Inventory, and The Way of Coping Strategy. Subjects were classified into 3 groups (addiction, over use, non addiction) by Internet Addiction Scale score. Prevalence of internet addiction was 4.3% and male adolescents were more addictive than female. Students who were mainly involved with internet chatting or game showed higher internet addiction score. The addiction group and over use group showed higher level of somatization, obsession, interpersonal sensitivity, depression, anxiety, hostility, and paranoia than non-addicted group. Addiction group and over use group used passive coping strategies more frequently in the stressful situation than nonaddicted group. Also, the regression analysis for finding out causal factors that predicts internet addiction showed that emotion relieving strategy were important variable which predict internet addiction. Interpersonal sensitivity and emotion relieving coping strategy was important to predict addiction. This study showed that problematic internet use was closely associated with psychopathology and psychiatric comorbidity. And high interpersonal sensitivity and emotion relieving coping strategy were related with internet addiction in adolescence.

한국인 당뇨병 및 비당뇨병 환자에서의 뇌혈관 질환 유무에 따른 PAI-1 촉진자 유전자형과 인슐린저항성에 관한 연구

오승준,김영설,박철영,김덕윤,김성운,양인명,김진우,최영길,팽정령,정경천 대한비만학회 2000 The Korean journal of obesity Vol.9 No.2

연구배경 : 혈전현상을 특징으로 하는 질환에서는 Plasminogen activator inhibitor-1 (PAI-1) 이 높은 활성도를 보이는데, PAI-1 치는 당뇨병, 심근경색증, 비만 등에서 높다고 밝혀진 바 있다. 또한 당뇨병 환자들의 합병증의 주요한 병인은 죽상경화증으로 혈전현상이 특징인 질환에서 증가하는 PAI-1이 당뇨병 환자에서 높다. 목적 : 정상인에서의 PAI-1 유전자 촉진자의 유전자형의 분포 및 혈액농도를 관찰하고, 당뇨병 및 뇌혈관 질환 환자군에서의 PAI-1 유전자 촉진자 유전자형의 분포 및 혈액농도를 측정하여 정상인과 차이점을 알아본다. 당뇨병 환자군에서의 혈장 PAI-1 치와 인슐린 저항성, 전구 인슐린 등과의 상관관계를 살펴보고, 인슐린저항성과 대혈관질환의 지표로 사용될 수 있는지 알아보았다. 방법 : 대상으로는 정상인 76명, 제2형 당뇨병 환자 56명, 뇌혈관질환이 동반된 제2형 당뇨병 환자 48명, 뇌혈관질환 환자 51명을 선택하여, 환자의 혈액에서 인슐린, 공복시 혈당, 전구인슐린, 중성지방, 총콜레스테롤 및 기타 생화학 검사 및 이학적 검사를 시행하였다. 환자의 DNA를 채취하여 전사개시 -675bp를 포함하는 대립형질 특이 시발체를 사용하여 중합효소 연쇄 반응을 실시하여, 그 유전자형을 판독하였다. 결과 : 정상 대조군 76명 (46.4±11.1세), 2형 당뇨병 환자 56명 (58.3±12.6세), 뇌경색증 환자 51명 (63.1±13.2세) 대상으로 하였다. PAI-1 촉진자 유전자형의 (4G/4G, 4G/5G, 5G/5G)빈도는 정상 대조군이 각각 23.7%, 75.0%, 1.3%, 뇌경색 환자군이 19.6%, 66.7%, 13.7%, 뇌경색이 동반된 당뇨병 환자군이 33.3%, 58.3%, 8.3% 였다. (X2=12.6, p=0.05). 이러한 사실은 서구인에 비해 4G/4G, 5G/5G 동형 유전자형이 낮은 결과였다. 각 군별 혈장 PAI-1 농도는 정상 대조군 13.4, 1.8 ~ 65.2 ng/mL (중앙값 , 범위 ) 2형 당뇨병 환자군 14.4, 2.9 ~ 47.8 ng/mL, 뇌경색 환자군 21.9, 6.2 ~ 154.7 ng/mL , 뇌경색이 동반된 2형 당뇨병 환자군 28.8, 3.2 ~ 139.3 ng/mL 로 차이를 보였다 (p=0.000). 전체 대상에서 PAI-1 촉진자 부위의 유전자형에 따른 PAI-1 활성도와 항원 농도는 차이를 보이지 않았다. 그러나 PAI-1 활성도는 혈중 중성지방, 전구인슐린, 체질량지수와 독립적인 상관관계를 보였다 (p=0.000, p=0.000 and p=0.005). 결론 : 결론적으로 PAI-1 촉진자 부위의 유전자형은 뇌경색증의 지표는 아니며, PAI-1 활성도를 결정짓는 인자는 유전적 요인보다는 혈중 중성지방, 전구 인슐린, 체질량지수와 같은 대사적 요인으로 생각된다. Plasminogen activator inhibitor-1 (PAI-1) is known be related to insulin resistance and several components of the large vascular disease. Notably, the high frequencies of diseases such as coronary heart disease or stroke are related to type 2 diabetes complications. We studied to find out whether the PAI-1 promother genotype could be a marker for cerebral infarction in type 2 patients. Subject patients were; 56 type 2 diabetics (age 58.3±12.6), 51 patients with cerebral infarction (age 63.1±13.2), 48 type 2 diabetics with cerebral infarction (age 64.8±9.3) , and 76 healthy control (age 46.4±11.1). The 4G/5G genotype of PAI-1 promoter was evaluated by polymerase chain reaction and endonuclease digestion. PAI-1 promoter genotype frequency (4G/4G, 4G/5G, 5G/5G) was 23.7%, 75.0% and 1.3% in healthy control, 17.9%, 67.9% and 14.3% in type 2 diabetes patients, 19.6%, 66.7% and 13.7% in cerebral infarction patients, 33.3%, 58.3% and 8.3% in type 2 diabetics with cerebral infarction (X^2=12.6, p=0.05). This finding is lower in frequency of 5G/5G homozygote than that reported in Caucasians. The plasma PAI-1 concentrations according to the disease were 13.4, 1.8 ~ 65.2 ng/mL (median, range) for healthy control, 14.4, 2.9 ~ 47.8 ng/mL for type 2 diabetes, 21.9 6.2 ~ 154.7 ng/mL for cerebral infarction , and 28.8, 3.2 ~ 139.3 ng/mL, for cerebral infarction with type 2 diabetes (p=0.000). In the all subjects, PAI-1 concentration and activity of PAI-1 promoter genotype did not show any significant difference. However, the PAI-1 activity was independently associated with serum triglyceride level, plasma proinsulin and BMI (p=0.000, p=0.000 and p=0.005 respectively). We concluded that PAI-1 genotype is not a marker for the cerebral infarction ; however, the genotype is related to PAI-1 concentration , and therefore it seems to be that metabolic factors such as triglyceride level or plasma proinsulin or BMI are more in relations with determining the PAI-1 concentration than the genotype.