Al-Sn 합금의 마찰 특성에 미치는 Sn 형상의 영향

李定根,朱大憲,金文鉉,金明鎬 대한금속재료학회 2002 대한금속·재료학회지 Vol.40 No.10

Effects of Sn morphology on the friction and wear characteristics of Al-Sn alloys were investigated by using the tribology tester, optical microscope and scanning electron microscope. Three different types of Sn morphologies named elongated, small network and large network structure were obtained by cladding and heat treatment. Wear resistance of the specimen having large network structure exhibited better anti-friction characteristics compare to that of the elongated structure. Also specific wear rate and friction coefficient decreased markedly with change of Sn morphology from elongated to large network structure. Abrasive and adhesive wear occurred for the elongated structure, while oxidation wear was observed for the network structure.

허혈성 심질환에서 염증지표에 관한 연구

번정득,권영주,박상호,한대희,이상철,강진환,김명구,심규혁,최병조,온영근,현민수,김성구 순천향의학연구소 2001 Journal of Soonchunhyang Medical Science Vol.7 No.2

Background : Atherosclerosis is the chief underlying cause of ischemic heart disease and there is increasing evidence that inflammation is an important determinant of the development of atherosclerosis. We assessed the levels of inflammatory markers in patients with ischemic heart disease and normal group who has normal coronary angiograms. Materials and Methods : Coronary angiography was performed in 142 patients. 107 patients of ischemic heart disease(stable angina pectoris 58, unstable angina pectoris 30, Acute myocardial infarction 19) and 38 normal control subjects. We assessed the level of inflammatory markers, such as CRP, ESR, fibrinogen and leukocyte. Results : CRP, ESR and fibrinogen values of the patients with stable angina pectoris and unstable angina pectoris were higher than that of normal control group, but there were no statistical significance. Leukocyte value of the patients with unstable angina pectoris(9003.3±701.5/mm^(3)) was significantly higher than that of the patients with stable angina pectoris(6685.5±245.8/mm^(3)) and normal control subjects(6394.3±235.1/mm^(3)). CRP, ESR and fibrinogen values of the patients with acute myocardial infarction were also higher than that of normal control subjects. CRP was 3.88±2.05 mg/dL in acute mocardial infarction group, and 0.29±0.15 mg/dL in normal control subject group(p<0.05). Fibrinogen was 541.6±45.1 mg/dL in acute myocardial infarction group, 321.4±25.6 mg/dL in normal control subject group(p<0.05). Leukocyte was 10942.1±737.6/mm^(3) in acute myocardial infarction group, 6394.3±235.1/mm^(3) in normal control subject group(p<0.05). Conclusions : This study demonstrate that CRP, fibrinogen and leukocyte values of acute myocardial infarction group were significantly higher than that of control group and stable, unstable argina pectoris group. Leucokyte values were significantly elevated in unstable angina group, but CRP values were not in unstable angina group.

十全大補湯이 抗癌劑를 投與한 생쥐의 胸腺細胞에 미치는 影響

金大根,殷載淳,全薰,宋正模 대한본초학회 1998 大韓本草學會誌 Vol.13 No.2

The purpose of this research was to investigate effects of Sipjeon-Daebo-Tang(SDT) on thymocytes of anti-tumor drugs administered mice. DNA fragmentation, mitochondrial transmembrane potential and subpopulation were tested using a flow cytometry. and the cell viability was tested using a MTT assay. Etoposide, vincristine and doxorubicin enhanced DNA fragmentation and reduced mitochondrial transmembrane potential of thymocytes, but SDT recoverd the action of vincristine and doxorubicin. Etoposide or vincristine decreased the population of CD4 single positive cell in thymocytes, but SDT enhanced the population of CD4+ single positive cell. Etoposide, vincristine and doxorubicin decreased the cell viability of thymocytes, but SDT enhanced the cell viability. These results suggest that SDT has a regulative function of thymocytes in anti-tumor drugs administered mice.

대한 응급의학회지 논문의 분석 및 고찰

손대곤,장석준,송근정,이한식 大韓應急醫學會 1997 대한응급의학회지 Vol.8 No.1

To raise the quality of research, medical articles which are feasible and objective must be continuously published and be continuously monitored. All articles published in the Journal of the Korean Society of Emergency from November, 1990 to November, 1995 were compared with a foreign emergency medical journal, the American Journal of Emergency Medicine(AJE). Classifying the articles in the Journal of the Korean Society of Emergency Medicine, there were 15 (8.4%) review articles, 145 (81.0%) original articles and 19 (10.6%) case reports. In the AJE, there were 103 (15.1%) review articles, 304 (44.4%) original articles and 277 (40.5%) case reports. Classifying the original articles in the Journal of the Korean Society of Emergency Medicine, There were 13 (9.0%) experimental articles, 88 (60.7%) descriptive articles and 44 (30.3%) analytic articles. In the AJE, there were 40 (13.2%) experimental articles, 59 (19.4%) descriptive articles and 205 (67.4%) analytic articles. The classification of original articles according to frequency in the Journal of the Korean Society of Emergency Medicine is trauma, resuscitation, toxicology and medical emergency, where as the AJE is medical emergency, trauma, toxicology and EMS. For statistical methods used in original articles, 90 (62.1%) case did not do any statistical analysis or where only descriptive statistics were used. In 6 (4.1%) cases the statistical level was described but statistical methods were nonmentioned. By simple calssificaton study, there were 44 (30.3%) cases of original articles in the Journal of the Korean Society of Emergency Medicine, and 6 (2.0%) cases in the AJE. Because the development of Emergency Medicine as a special department is based on logical articles, organization of articles have study design, make hypothesis, sample gathering, statistical analysis and feasibility of conclusion. For this, the emergency training course needs a course on research methodology.

베타-글루쿠로니다제에 의한 황련ㆍ황금 공침물의 가수분해 및 생체이용률 증가

김미정,김남순,김영일,김대근,양재헌 한국약제학회 2003 Journal of Pharmaceutical Investigation Vol.33 No.2

During the preparation of decoction from the mixture of Coptidis Rhizoma and Scutellariae Radix, insoluble copreciptate was formed. The coprecipitated product(COP) was composed of berberine and baicalin which was the active ingredient of Coptidis Rhizoma and Scutellariae Radix, respectively. COP was slightly soluble in water and could not be well absorbed after oral administration. This poor bioavailibility might be associated with its poor aqueous solubility. With the purpose of increasing the solubility and bioavailibility of COP, hydrolysis of COP by β-glucuronidase was carried out. Hydrolyzed products (HOP) of COP were identified and assayed for active ingredients. The partition coefficient study, in situ absorption test, and pharmacokinetic study after oral administration were also performed. COP was found to be consisted of berberine and baicalin with molecular ratio or 1 to 1. This compound was hydrolyzed to berberine and baicalin by β-glucuronidase. The rate of hydrolysis was higher at higher temperature up to 50℃ and higher concentration of β-glucuronidase up to 2500 unit under our experimental conditions. Baicalein, which is more liphophilic than baicalin, showed greater absorption in small intestine than baicalin did. The plasma concentrations of berberine and baicalein after oral administration of HOP were significantly higher than those of COP. The possible mechanism of increased bioavailibility of berberine and baicalein could be the hydrolysis of COP by β-glucuronidase. On the basis of the above results, it might be said that HOP should be a suitable preparation for increasing the bioavailibility of Coptidis Rhizoma and Scutellariae Radix.

Pd/C 촉매에 의한 2-(2-hydroxy-5-methyl-phenyl)-2H-benzotriazole 합성 반응의 특성

최주홍,이정원,이대광,이동근 慶尙大學校生産技術硏究所 1994 生産技術硏究所論文集 Vol.10 No.-

The reduction process using Pd catalyst is very attractive in the view points of the simple reaction step and the relatively less discharge of pollutants. The reduction characteristics of o-nitrohydroxyazobenzene(O-NHAB) with Pd/c catalyst was investigated in an autoclave and a reactor operated at atmospheric pressure. The reduction performance of O-NHBA in the auto clave showed high pressure gave good yield for tinuvin P. The maximum yield of tinuvin P based on o-nitroaniline was 63.3%. Some contents of water in the solution improved the reaction rate ad reduced the formation of impurities. Reaction temperature was able to be increased up to 75℃ with the relatively less impurities. The optimum content of NBA was about 10%.

8년간(1992~1999) 산업안전보건연구원에 의뢰된 직업병 심의 사례 분석

강성규,김규상,김양호,최정근,안연순,진영우,최병순,양정선,김은아,채창호,최용휴,김대성,박정선,정호근 대한산업의학회 2000 대한직업환경의학회지 Vol.12 No.2

Objectives : Pneumoconisis and noise-induced hearing loss (NIHL) have been reported as main occupational diseases by the Special Health Examination. The Industrial Accident Compensation Insurance has reported various work-related diseases, however, these two diseases occupied almost a half of compensated cases. Therefore, it was not well known about the status of occupational diseases other than pneumoconiosis, NIHL, and cardio-cerebrovascular accident (CVA). This study was conducted to analyze claimed cases as an occupational disease, that was requested to the Korea Industrial Safety and Health Agency (KOSHA). Methods : The local office of the Korea Labor Welfare Corporation (KLWC) has asked the KOSHA for confirmation of claimed cases as an occupational disease. We analyzed 379 cases requested from KLWC, the Ministry of Labor, employers, unions and occupational health agencies from 1992 to 1999. Results : Male was 80.7 % of the requested cases. Their mean age was 42 years old and 75.5 % of them were more than 35 years old. The requested cases were increased rapidly from 25 cases in 1992 to 108 cases in 1999 and the accept rate was 50.7 %. The majority of requested cases were respiratory diseases(22.4%), cancers(18.5%), Neuropsychiatric problems(14.5%), and musculoskeletal problems(13.5%). The accept rate was high in reproductive, respiratory, musculoskeletal and digestive disorders and low in neuropsychiatric, renal and otologic problems and occupational cancers. 73.6% of them were caused by chemical agents, especially 28.5 % were by organic solvents. 67% of them were clinically confirmed at university hospitals. A half of the cases were from KyongIn area, even the request came from the whole country. Conclusions : A claim was common in workers whose age was over 35 years old and exposure history was over 10 years. The respiratory diseases and neuropsychiatric disorders were still main problems in occupational health and occupational cancers was increasing even though its accept rate was not high yet.

관상동맥질환 환자에서 스텐트 시술 후 재협착에 관한 연구

강진환,권영주,박상호,한대희,이상철,김명구,변정득,최병조,심규혁,온영근,현민수,김성구 순천향의학연구소 2001 Journal of Soonchunhyang Medical Science Vol.7 No.2

Background and aims : In the coronary artery disease, a rate of restenosis was much decreased by placement of coronary stent than when percutaneous transluminal coronary angioplasty has been applied, but there are still important clinical problems of restenosis. There has been many progressive studies about various factors contributed to this restenosis. So, we studied a relation between restenosis after placement of coronary stent in the coronary artery disease and many clinical factors, characteristics of stenotic lesion and procedural factors, and also assessed the restenosis rate of various coronary stents. Methods : Total 58 lesions(46 cases of patients ; man 30, woman 16) were evaluated, which has been performed a follow-up coronary angiography after 6 months (mean 188 days) since coronary stent had been placed. Various stents were implanted and assessed a relation between restenosis and many factors. Results : Of 58 lesions were target stenotic studies, there were 22 of restenotic lesions(37.9%), and the restenosis rate wes statistically significant difference in the relation with diabetes mellitus(p<0.05), group of acute myocardial infarction(p<0.05) among clinical diagnosis of ischemic heart disease(stable angina, unstable angina and acute myocardial infarction) in clinical factors and with high dilation pressure of stent(p<0.05) in procedural factors. When the rate of restenosis was evaluated among implanted stents, it was lowest in the Multilink^(®) stent and highest in the Nir Royal^(®) stent(60%). Conclusion : In this study of restenosis and various factors after placement of stents in the coronary artety disease, factors such as diabetes mellitus, group of acute myocardial infarction and a dilation pressure of stent were significant related with restenosis and the restenosis rate of Multilink^(®) stent was lowest and the highest restenosis rate was of Nir Royal^(®) stent.

만성 심부전환자의 혈액에서 측정한 Tumor necrosis factor-α 및 Interleukin-6의 임상적 의의

김명구,김성구,박상호,한대희,강진환,변정득,심규혁,최병조,방덕원,온영근,현민수,권영주 순천향의학연구소 2001 Journal of Soonchunhyang Medical Science Vol.7 No.2

Background and objectives: Many conditions are responsible for the pathophysiology and progressive mechanisms of congestive heart failure. More recently, it has also become evidence that another class of biologycally activated molecules generically reffered to as cytokine these are also over expressed in congestive heart failure. Therefore, the purpose of this study was to measure concentrations of tumor necrosis factor-α(TNF-α), interleukin-6(IL-6) in mild to severe symptoms of heart failure and compare their values with those found in normal control and analysed correlation relationship between cytokine level, clinical findings and hemodynamic indicies. Subjects and Methodology: Levels of TNF-α and IL-6 were measured on pulmonary artery during cardiac catheterization in heart failure patients(n=32) and normal subjects(n=8) as well as physical examination and echocardiogram. Cytokines assay were performed on plasma using commercially available ELISA(Enazyme-Linked Immunosorbent Assay) kits. Results: Although the levels of TNF-α and IL-6 tend to increase in congestive heart failure group, the cytokines level was not made significantly statistical difference between congestive heart failure group and controls. When analyzing the correlation between the levels of PCWP(pulmonary capillary wedge pressure) and cytokines(TNF-α, IL-6), respectively, there were statistically significant correlation coefficient 0.32,(p<0.05), 0.39(p<0.01). The cytokine IL-6 and pressure of pulmonary artery were significant correlation.(correlation coefficient 0.36, p<0.02) More significantly, there was correlated with TNF-α and IL-6.(correlation coefficient 0.57, p<0.001) Conclusions: There was tended toward high concentration of TNF-α & IL-6 in congestive heart failure and significant difference for PCWP between TNF-α & IL-6, thus may be correlated with development and progression in congestive heart failure.

The Effects of Breathing Exercise on Respiratory Synergist Muscle Activity and SpO₂ in Patients with Chronic Obstructive Pulmonary Disease

( Dae-keun Jeong ) 대한물리치료학회 2015 대한물리치료학회지 Vol.27 No.4

Purpose: This study is not a fragmentary study on characteristics of respiratory synergist when breathing, however it was intended to determine the effect of currently available respiratory exercise and to provide basic clinical information through investigation of oxygen demand and respiratory synergist that mobilizes for respiration during application of respiratory exercise. Methods: Experimental group I was selected from second grade of severity classification of GOLD, which has the highest percentage among patients with COPD, and experimental group II was selected from third grade of severity classification as a clinical sampling. After respiration pursing up lips and diaphragm respiration exercise were mediated together for six weeks, activity of respiratory muscles and oxygen saturation were measured and analyzed. Results: In comparison of change of respiratory synergist and oxygen saturation, activity of respiratory synergist in sternocleidomastoid muscle and scalene muscle showed a meaningful decrease in experimental group I. And, in comparison of change of respiratory synergist and oxygen saturation, activity of respiratory synergist in rectus abdominis muscle showed a meaningful increase in experimental group II. In comparison of change of respiratory synergist and oxygen saturation, activity of respiratory synergist in sternocleidomastoid muscle, scalene muscle, and rectus abdominis muscle showed a meaningful difference between experimental groups. Conclusion: Respiratory synergists work mainly as agonist of chest and upper limbs. Therefore it is very important to lower mobilization of respiratory synergist when breathing. It is considered that a multilateral approach and continued clinical research for improvement of respiratory function for patients with COPD will be needed in the future.