기계적 피로결함 시험편 제조 및 결함 크기 평가

홍재근,김우성,손영호,박반욱 한국비파괴검사학회 2003 한국비파괴검사학회지 Vol.23 No.1

원자력발전소의 안전성등급 기기에 적용되는 비파괴검사는 실제 결함을 실현한 시험편을 사용하여 결함 탐지능력을 검증하도록 하는 기량검증이 요구되고 있다. 가동중인 원전에서 발생 가능한 균열으로는 기계적 피로균열, 열 피로균열 및 입계부식균열 등이 있으나 본 연구에서는 기계적 피로균열을 대상으로 하였다. 인장 피로하중을 사용하여 기계적 피로결함을 제조하기 위해서 시험편을 설계하였고 원하는 피로결함 파면의 조도를 얻기 위해서 인가하중의 크기 및 사이클 수를 조절하여 피로결함을 발생시켰다. 발생된 결함에 대한 정확한 크기와 위치에 대한 물리적 정보를 얻은 후에 결함이 설계된 크기와 위치에 존재하도록 기밀용접을 실시하였다. 기밀용접 후 잔여 용접 홈은 가스 텅스텐 아크용접 및 플럭스 코어드 아크용접으로 채워졌다. 최종 완성된 피로결함 시험편을 방사선투과검사 및 초음파탐상검사를 통하여 검사한 결과, 설계된 길이와 깊이로 피로결함이 형성되었음을 확인하였다. Performance demonstration with real flawed specimens has been strongly required for nondestructive evaluation of safety class components in nuclear power plant. Mechanical or thermal fatigue crack and intergranular stress corrosion cracking could be occured in the in-service nuclear power plant and mechanical fatigue crack was selected to study in this paper. Specimen was designed to produce mechanical fatigue flaw under tensile stress. The number of cycles and the level of stress were controlled to obtain the desired flaw roughness. After the accurate physical measurement of the flaw size and location, fracture surface was seal-welded in place to ensure the designed location and size. The remaining weld groove was then filled by using gas-tungsten arc welding(GTAW) and flux-cored arc welding(FCAW). Results of radiographic and ultrasonic testing showed that fatigue cracks were consistent with the designed size and location in the final specimens.

남제주 화력발전소의 증설과 저감대대책의 영향 분석

이화운,김유근,정우식,오은주,임헌호,노순아,반수진,최현정,김민선,김헌숙 부산대학교 환경문제연구소 2002 環境硏究報 Vol.20 No.-

In the view of the results investigated the effect of air pollutants that is emitted from a new generator facilities, the total estimated concentration which is the summation of a contributional concentration and observational concentration is much less than that of atmospheric environment criterion for the air pollutants. So we can predict that the operation of the new generator facilities with mitigation equipment don't seriously affect around environment. At the same time, we compared the contributional concentration of before mitigation equipment with that of after it to examine the decreasing amount due to mitigation equipment. The result showed that the concentration of SO2, NO2 and PM-10 is reduced to 25%, 30% and 26% of original value, respectively.

Incorporating smoking cessation interventions into lung cancer screening programs

( Woo Ho Ban ) 대한결핵 및 호흡기학회 2019 대한결핵 및 호흡기학회 추계학술대회 초록집 Vol.127 No.-

Poster Session : PS 1606 ; Lung Cancer : Dyspnea as an Independent Prognostic Factor in Patients with Non-Small Cell Lung Cancer

( Woo Ho Ban ),( Jong Min Lee ),( Jick Hwan Ha ),( Chang Dong Yeo ),( Hyeon Hui Kang ),( Chinkook Rhee ),( Hwasik Moon ),( Sang Haak Lee ) 대한내과학회 2014 대한내과학회 추계학술대회 Vol.2014 No.1

Background: Non-small cell lung cancer (NSCLC) is one of the most fatal cancers worldwide. Age, performance status and stage are well-known prognostic factors for patients with NSCLC. Dyspnea is a common and distressing symptom in patients with NSCLC, however, the prognostic value of dyspnea remains uncertain. Methods: We retrospectively reviewed a prospective lung cancer database of St. Paul`s Hospital, The Catholic University of Korea, from 2001 to 2014. Dyspnea using mMRC scales and clinicopathologic parameters were analyzed to identity their prognostic roles. Results: Total 457 NSCLC patients were enrolled, 259 (56.7%) patients complained of dyspnea at initial presentation. Except 109 (42.1%) patients with unknown mMRC scales, there were 85 (32.8%) patients with mMRC grade 0 or 1, and 65 (25.1%) patients had mMRC grade 2 or higher. Pulmonary function parameters were signifi cantly decreased in patients with dyspnea, compared to those without dyspnea. The median survival for patients with dyspnea was shorter than those without dyspnea (7 vs. 15 months, p < .001). A signifi cant difference in median survival was also found between patients with mMRC grade 0 or 1 and those with mMRC grade 2 or higher (11 vs. 6 months, p < .001). In multivariate analysis, age (HR, 1.60; 95% CI: 1.20-2.14), poor performance status (HR, 3.67; 95% CI: 2.34-5.77), advanced stage (HR, 2.85; 95% CI: 1.93-4.22), FEV1 level (HR, 0.99; 95% CI: 0.99-1.00) and dyspnea of mMRC grade 2 or higher (HR, 1.89; 95% CI: 1.32-2.70) were associated with poor outcome. Conclusions: These results suggest dyspnea could be an independent prognostic factor for patients with NSCLC. Therefore, clinicians are required to pay more attention to NSCLC patients` complaining of dyspnea, individually.

Clinical significance of nuclear factor erythroid 2-related factor 2 in patients with chronic obstruc-tive pulmonary disease

( Woo Ho Ban ),( Hyeon Hui Kang ),( In Kyoung Kim ),( Jick Hwan Ha ),( Hyonsoo Joo ),( Jong Min Lee ),( Jeong Uk Lim ),( Sang Haak Lee ),( Chin Kook Rhee ) 대한내과학회 2018 The Korean Journal of Internal Medicine Vol.33 No.4

Background/Aims: Several studies have identified a role for nuclear factor erythroid 2-related factor 2 (Nrf2) in the development of chronic obstructive pulmonary disease (COPD). However, the relationship between the plasma Nrf2 level and the extent of systemic inflammation associated with COPD status remains unclear. Methods: Patients diagnosed with COPD were recruited from St. Paul’s Hospital, The Catholic University of Korea, between July 2009 and May 2012. Patients were classified into two groups according to the severity of their symptoms on initial presentation, a COPD-stable group (n = 25) and a COPD-exacerbation group (n = 30). Seventeen patients were enrolled as a control group (n = 17). The plasma levels of Nrf2 and other systemic inf lammatory biomarkers, including interleukin 6 (IL-6), surfactant protein D (SP-D), and C-reactive protein (CRP), were measured. We collected clinical data including pulmonary function test results, and analyzed the relationships between the biomarker levels and the clinical parameters. Results: Plasma Nrf2 and CRP levels significantly increased in a stepwise manner with an increase in inflammatory status (control vs. COPD-stable vs. COPD-exacerbation) (p = 0.002, p < 0.001). Other biomarkers of systemic inflammation (IL-6, SP-D) exhibited similar tendencies, but significant differences were not apparent. Furthermore, we observed negative correlations between the plasma level of Nrf2 and both the forced expiratory volume in 1 second (FEV₁) (r = -0.339, p = 0.015) and the forced expiratory ratio (FEV₁/forced vital capacity [FVC]) (r = -0.342, p = 0.014). However, CRP level was not correlated with any measured parameter. Conclusions: Plasma Nrf2 levels gradually increased in line with disease severity and the extent of systemic inflammation in patients with COPD.

Smoking habit and blood heavy metal level of active electronic cigarette smokers : data from the 2013-2017 KNHANES

( Woo Ho Ban ),( Sang Haak Lee ),( Hye Seon Kang ) 대한결핵 및 호흡기학회 2019 대한결핵 및 호흡기학회 추계학술대회 초록집 Vol.127 No.-

Introduction: The use of electronic cigarette (e-cig) is expanding rapidly. However, there has been little research on the relationship between actual smoking habit and blood heavy metal levels of e-cig smokers. Methods: This study used data from sixth (2013- 15) and seventh (2016-17) Korea National Health and Nutritional Examination Surveys. Total 12,192 subjects who had completed smoking behavior survey and measurements of urine cotinine and blood heavy metal level were enrolled in this study. We categorized them into three groups; active e-cig smokers (who smoked e-cig in the last 30 days), conventional cigarette (c-cig) smokers, never smokers. We compared smoking habit, urine cotinine level and blood heavy metal levels among them. Results: Of the 12,192 subjects, 214 (1.8%) were active e-cig smokers, 1,884 (15.5%) were c-cig smokers, 10,094 (82.8%) were never smokers. Average smoking amount (14.08 ± 7.14 vs. 13.16 ± 7.93, p = 0.137) and urine cotinine level (316.51 ± 255.8 vs. 325.11 ± 263.8, p = 0.6736) were similar in both e-cig and c-cig smokers. Average time to first cigarettes of active e-cig smokers were significantly shorter than the c-cig smokers (27.92 ± 22.61 vs. 33.56 ± 23.27, p = 0.039). After adjustment for age, gender, occupation, socioeconomic and education status, the blood lead (2.11 ± 0.08 vs. 2.18 ± 0.03 vs. 1.95 ± 0.02, p = <0.0001) and cadmium (1.39 ± 0.06 vs. 1.41 ± 0.02 vs. 0.97 ± 0.01, p = <0.0001) level were significantly higher in both e-cig and c-cig smokers than never smokers. Conclusions: The amount of smoking, nicotine dependency and blood heavy metal levels of active e-cig smokers were similarly high to that of c-cig smokers.

Thematic Poster : TP-66 ; Dyspnea as an Independent Prognostic Factor in Patients with Non-Small Cell Lung Cancer

( Woo Ho Ban ),( Jong Min Lee ),( Jickhwan Ha ),( Chang Dong Yeo ),( Hyeon Hui Kang ),( Chinkook Rhee ),( Hwasik Moon ),( Sang Haak Lee ) 대한결핵 및 호흡기학회 2014 대한결핵 및 호흡기학회 추계학술대회 초록집 Vol.118 No.0

Background: Non-small cell lung cancer (NSCLC) is one of the most fatal cancers worldwide. Age, performance status and stage are well-known prognostic factors for patients with NSCLC. Dyspnea is a common and distressing symptom in patients with NSCLC, however, the prognostic value of dyspnea remains uncertain. Methods: We retrospectively reviewed a prospective lung cancer database of St. Paul’s Hospital, The Catholic University of Korea, from 2001 to 2014. Dyspnea using mMRC scales and clinicopathologic parameters were analyzed to identity their prognostic roles. Results: Total 457 NSCLC patients were enrolled, 259 (56.7%) patients complained of dyspnea at initial presentation. Except 109 (42.1%) patients with unknown mMRC scales, there were 85 (32.8%) patients with mMRC grade 0 or 1, and 65 (25.1%) patients had mMRC grade 2 or higher. Pulmonary function parameters were significantly decreased in patients with dyspnea, compared to those without dyspnea. The median survival for patients with dyspnea was shorter than those without dyspnea (7 vs. 15 months, p < .001). A significant difference in median survival was also found between patients with mMRC grade 0 or 1 and those with mMRC grade 2 or higher (11 vs. 6 months, p < .001). In multivariate analysis, age (HR, 1.60; 95% CI: 1.20-2.14), poor performance status (HR, 3.67; 95% CI: 2.34-5.77), advanced stage (HR, 2.85; 95% CI: 1.93-4.22), FEV1 level (HR, 0.99; 95% CI: 0.99-1.00) and dyspnea of mMRC grade 2 or higher (HR, 1.89; 95% CI: 1.32-2.70) were associated with poor outcome. Conclusions: These results suggest dyspnea could be an independent prognostic factor for patients with NSCLC. Therefore, clinicians are required to pay more attention to NSCLC patients’ complaining of dyspnea, individually.

Role of Nuclear Factor Erythroid 2‒Related Factor 2 in Chronic Obstructive Pulmonary Disease

Woo Ho Ban,이진국 대한결핵및호흡기학회 2022 Tuberculosis and Respiratory Diseases Vol.85 No.3

Chronic obstructive pulmonary disease (COPD) is characterized by airflow limitation due to chronic airway inflammation and destruction of the alveolar structure from persistent exposure to oxidative stress. The body has various antioxidant mechanisms for efficiently coping with such oxidative stress. The nuclear factor erythroid 2-related factor 2 (Nrf2)–antioxidant response element (ARE) is a representative system. Dysregulation of the Nrf2-ARE pathway is responsible for the development and promotion of COPD. Furthermore, COPD severity is also closely related to this pathway. There has been a clinical impetus to use Nrf2 for diagnostic and therapeutic purposes. Therefore, in this work, we systematically reviewed the clinical significance of Nrf2 in COPD patients, and discuss the value of Nrf2 as a potential COPD biomarker.

Clinical significance of nontuberculous mycobacteria isolation in patient with tuberculosis

( Woo Ho Ban ),( Ji Young Kang ),( Hye Seon Kang ),( Eung Gu Lee ) 대한결핵 및 호흡기학회 2019 대한결핵 및 호흡기학회 추계학술대회 초록집 Vol.127 No.-

Introduction: Researches on clinical significance of isolated nontuberculous mycobacteria (NTM) from patients with tuberculosis are lacking. Thus, this study investigated clinical significance of NTM isolation in patients with tuberculosis. Methods: From 2009 to 2016, we retrospectively reviewed NTM culture positive cases in patients who completed or continued anti-TB treatment during study period. We categorized them into two groups according to number of NTM isolation (Single detection vs. Multiple detection). Then we compared clinical characteristics and clinical outcomes among them. Results: Of the 100 subjects, 77 were single detection group, 23 were multiple detection group. History of bronchiectasis was reported more frequently in a multiple detection group than a single detection group (17.4% vs. 3.9%, p = 0.049). Treatment outcomes of tuberculosis were similar in both groups. Initial high bacilli burdens of NTM (smear positivity) were observed more often in multiple detection group (17.4% vs. 2.6%, p = 0.033). The most frequently isolated NTM species was M. abscessus in multiple detection group (n=3, 25.0%), otherwise M. avium complex (n=12, 38.7%) in single detection group. Cases of compatible NTM-pulmonary disease were 9 (39.1%) cases in multiple detection group, 4 in single detection (5.3%). Radiologic progression was more frequently observed in multiple detection group. Conclusions: Multiple isolation of NTM in patients with tuberculosis is associated with structural lung abnormality of host, high bacilli burdens, high virulence and poor clinical outcomes.

Applying the lung cancer screening eligibility criteria to the real lung cancer multicenter cohort: Impact of smoking amount on clinicopathological features and survival in NSCLC

( Woo Ho Ban ),( Sung Kyoung Kim ),( Chang Dong Yeo ),( Hye Seon Kang ),( Chan Kwon Park ),( Ju Sang Kim ),( Jin Woo Kim ),( Seung Joon Kim ),( Sang Haak Lee ) 대한결핵 및 호흡기학회 2019 대한결핵 및 호흡기학회 추계학술대회 초록집 Vol.127 No.-

Introduction: Screening for the early detection of lung cancer has been performed in high-risk individuals as smoking history. However, there has been a lack of research on the distribution, clinical characteristics and prognosis of these high-risk individuals in the actual cohort. Methods: The present study used the lung cancer cohort of the Catholic Medical Centers at the Catholic University of Korea from 2014 to 2017. We enrolled patients with non-small lung cancer and we categorized the patients as their smoking history identically the national lung screening trial (NLST) guideline into high and low-risk groups. We estimated distribution, clinical characteristics and survival data among each group. Results: Of the 439 patients, 223 (50.8%) patients were high-risk group. Patients with high-risk group had unfavorable clinical characteristics and tumor biologic features. Overall survival of the high-risk group was significantly shorter than low-risk group in both early (I, II) and advanced stages (III, IV). In multivariate analysis, heavy smoking remained one of the most important poor clinical prognostic factors in patients with lung cancer and it has been shown to have a dose-dependent relationship on patients’ survival. Conclusions: High-risk individuals have poor clinical outcomes and the patient’s prognosis seemed to be deteriorated as smoking amount increased. Therefore, active screening and clinical attention were needed in the high-risk individuals.