• BMB Reports
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• 제36권1호
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• pp.1-11
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• 2003

The causative role of polycyclic aromatic hydrocarbons (PAH) in human carcinogenesis is undisputed. Measurements of PAH-DNA adduct levels in easily accessible white blood cells therefore represent useful early endpoints in exposure intervention of chemoprevention studies. The successful applicability of DNA adducts as early endpoints depends on several criteria:i.adduct levels in easily accessible surrogate tissues should reflect adduct levels in target-tissues, ii. toxicokinetics and the temporal relevance should be properly defined.iii. sources of inter- and intra-individual variability must be known and controllable, and finally iv. adduct analyses must have advantages as compared to other markers of PAH-exposure. In general, higher DNA adduct levels or a higher proportion of subjects with detectable DNA adduct levels were found in exposed individuals as compared with non-exposed subjects, but saturation may occur at high exposures. Furthermore, DNA adduct levels varied according to changes in exposure, for example smoking cessation resulted in lower DNA adduct levels and adduct levels paralleled seasonal variations of air-pollution. Intra-individual variation during continuous exposure was low over a short period of time (weeks), but varied significantly when longer time periods (months) were investigated. Inter-individual variation is currently only partly explained by genetic polymorphisms in genes involved in PAH-metabolism and deserves further investigation. DNA adduct measurement may have three advantages over traditional exposure assessment: i. they can smooth the extreme variability in exposure which is typical for environmental toxicants and may integrate exposure over a longer period of time. Therefore, DNA adduct assessment may reduce the monitoring effort. ii. Biological monitoring of DNA adducts accounts for all exposure routes. iii. DNA adducts may account for inter-individual differences in uptake, elimination, distribution, metabolism and repair amongst exposed individuals. In conclusion, there is now a sufficiently large scientific basis to justify the application of DNA adduct measurement as biomarkers in exposure assessment and intervention studies. Their use in risk-assessment, however, requires further investigation.

• Safety and Health at Work
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• 제13권2호
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• pp.148-154
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• 2022

Background: Bus driving is a mentally demanding activity that requires prolonged attention to ensure safety. The aim of the study was to assess mental fatigue caused by driving a public bus and to find a profile of workers at higher risk. Methods: We evaluated changes of critical flicker fusion (CFF) (index of central arousal) and heart rate variability (HRV) (index of autonomic balance) in a 6-hour driving shift on a real route, in 31 professional bus drivers, and we tested the influence of personal factors such as sleep quality, BMI, and age. Paired t-test was used to test differences of CFF and HRV between both initial and final phase of driving, while multiple linear regression tested the influence of personal variables on the indexes of mental fatigue. Results: Results showed that CFF significantly decreased after 6 hours of bus driving (41.91 Hz, sd 3.31 vs. 41.15 Hz, sd 3.15; p = 0.041), and heart rate significantly decreased in the final phase of driving, with respect to the initial phase (85 vs. 78 bpm, p = 0.027). Increasing age (beta = -0.729, p = 0.022), risk of obstructive sleep apnea syndrome (beta = -0.530, p = 0.04), and diurnal sleepiness (beta = -0.406, p = 0.017) showed a significant effect on influencing mental fatigue. Conclusion: Elderly drivers at higher risk of sleep disorders are more prone to mental fatigue, when exposed to driving activity. Monitoring indexes of central arousal and autonomic balance, coupled with the use of structured questionnaires can represent a useful strategy to detect profile of workers at higher risk of mental fatigue in such duty.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2002년도 학술대회지
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• pp.306-310
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• 2002

1990년대의 우루과이 라운드 협정과 최근에 시작된 뉴라운드 협상 등에 의한 건설시장의 세계화 추세는 해외건설시장을 질적${\cdot}$ 양적으로 변화시키고 있다. 세계화된 건설시장은 건설업체에게는 해외건설시장의 수주규모를 확대시킬 수 있는 기회를 제공하기도 하지만 해외건설사업 진출에 따른 리스크도 급격히 증가시키는 양면성을 갖고 있다. 일례로 ENR에 따르면 해외건설사업에 진출하고 있는 세계 상위 225대 건설업체들 중 $13.9\%$ 가량이 손실을 경험하고 있으며, 년간평균 수익률 또한 지속적으로 하락하고 있다. 이로 인해 최근 일부 국내 건설업체들이 해외진출을 기피하는 경향까지 보이고 있다. 그러나 한정된 국내건설시장의 한계를 극복하고 건설산업을 지속적으로 발전시키기 위해서는 해외시장 진출에 적극적인 자세를 갖는 것과 함께 수익성을 높일 수 있는 전략을 수립하는 것이 필요하다. 본 연구는 해외건설사업의 수익성에 영향을 미치는 리스크에 대한 체계적인 대응전략을 마련하기 위한 연구의 한 단계로서 지난 35년 간의 해외건설공사의 수익성 추이를 살펴보고, 국내업체가 수행한 59개 해외건설공사를 대상으로 설문 및 방문조사를 실시하여 해외건설공사의 수익성에 영향을 미치는 주요인자를 규명하였다. 여기서 도출된 주요인자들은 향후 해외건설사업 수행을 위한 정형화된 리스크 관리기법 개발을 위한 기초자료로 활용될 것이다.

• Tuberculosis and Respiratory Diseases
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• 제80권1호
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• pp.45-51
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• 2017

Background: Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a minimally invasive diagnostic method for mediastinal and hilar lymphadenopathy. This study aimed to investigate the incidence of fever following EBUS-TBNA. Methods: A total of 684 patients who underwent EBUS-TBNA from May 2010 to July 2012 at Seoul National University Hospital were retrospectively reviewed. The patients were evaluated for fever by a physician every 6-8 hours during the first 24 hours following EBUS-TBNA. Fever was defined as an increase in axillary body temperature over $37.8^{\circ}C$. Results: Fever after EBUS-TBNA developed in 110 of 552 patients (20%). The median onset time and duration of fever was 7 hours (range, 0.5-32 hours) after EBUS-TBNA and 7 hours (range, 1-52 hours), respectively, and the median peak body temperature was $38.3^{\circ}C$ (range, $137.8-39.9^{\circ}C$). In most patients, fever subsided within 24 hours; however, six cases (1.1%) developed fever lasting longer than 24 hours. Infectious complications developed in three cases (0.54%) (pneumonia, 2; mediastinal abscess, 1), and all three patients had diabetes mellitus. The number or location of sampled lymph nodes and necrosis of lymph node were not associated with fever after EBUS-TBNA. Multiple logistic regression analysis did not reveal any risk factors for developing fever after EBUS-TBNA. Conclusion: Fever is relatively common after EBUS-TBNA, but is transient in most patients. However, clinicians should be aware of the possibility of infectious complications among patients with diabetes mellitus.

• Tuberculosis and Respiratory Diseases
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• 제81권4호
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• pp.330-338
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• 2018

Background: We developed an additional laser guidance system to improve the efficacy and safety of conventional computed tomography (CT)-guided percutaneous transthoracic needle biopsy (PTNB), and we conducted this study to evaluate the efficacy and safety of our system. Methods: We retrospectively analyzed the medical records of 244 patients who underwent CT-guided PTNB using our additional laser guidance system from July 1, 2015, to January 20, 2016. Results: There were nine false-negative results among the 238 total cases. The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of our system for diagnosing malignancy were 94.4% (152/161), 100% (77/77), 100% (152/152), 89.5% (77/86), and 96.2% (229/238), respectively. The results of univariate analysis showed that the risk factors for a false-negative result were male sex (p=0.029), a final diagnosis of malignancy (p=0.033), a lesion in the lower lobe (p=0.035), shorter distance from the skin to the target lesion (p=0.003), and shorter distance from the pleura to the target lesion (p=0.006). The overall complication rate was 30.5% (74/243). Pneumothorax, hemoptysis, and hemothorax occurred in 21.8% (53/243), 9.1% (22/243), and 1.6% (4/243) of cases, respectively. Conclusion: The additional laser guidance system might be a highly economical and efficient method to improve the diagnostic efficacy and safety of conventional CT-guided PTNB even if performed by inexperienced pulmonologists.

• 한국수자원학회논문집
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• 제42권8호
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• pp.591-605
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• 2009

본 연구에서는 하천제방의 침식, 침투영향을 고려한 위험도 및 통합위험도를 산정하였다. 이를 위해 추계학적 강우변동 생성기법을 이용하여 생성된 태풍기와 장마기별 유량 및 수위수문곡선을 활용하여 하천제방에 대한 침식, 침투 그리고 통합 위험도를 산정하였다. 침식에 대한 하천제방의 위험도는 허용 소류력을 이용하여 평가하였고 침투류 해석은 각 제방별로 대표 제방단면을 선정 후 SEEP/W 모형을 통해 해석을 실시하였으며 한계동수경사법을 이용한 MFOSM 분석을 통해 제방의 침투붕괴 위험도를 산정하였다. 본 연구에서는 확정론적 분석방법과 달리 정량적인 위험도를 산정할 수 있었고 실제 강우 변동의 특성 및 다양한 제방파괴 요인을 반영하였으며, 이를 하나의 위험도로 통합하여 제시하고 있으므로 본 연구모형의 결과는 그 적용성에 있어 매우 유용할 것으로 판단된다. 본 연구모형은 향후 홍수에 대한 제방파괴 위험지점 파악 및 제내지 홍수위험도와 연계한 홍수보험, 주민대피지도 구축 등에 활용 될 수 있어 유역의 홍수통합관리시 효율적이고 체계적인 대책수립에 크게 기여할 것으로 판단된다.

• Journal of Chest Surgery
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• 제28권3호
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• pp.247-252
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• 1995

The isolated coronary ostial stenosis is rare and a critical lesion which requires urgent surgical intervention. Recently direct angioplasty is assumed as a preferable approach to conventional bypass grafting. From Mar. 1990 to Aug. 1993, six patients underwent direct angioplasty in Sejong Heart Institute. The mean age of 6 patients was 48 years [range 37 to 63 and they consisted with 5 females and one male. All had severe angina [class III or IV of short duration [mean 5.3 months and a low incidence of risk factors. Despite the crucial location of the lesion, most patients had well preserved left ventricular function and normal wall motion. We performed direct angioplasty with autologous pericardium via anterior approach except one patient who underwent direct angioplasty and CABG. One patient died 4 hours after angioplasty probably due to acute coronary dissection. The survived 5 patients maintain normal life without symptoms during 26.2 months follow up [range 5 to 47 months .Our preliminary results suggest that angioplasty of isolated coronary ostial stenosis in highly selected patient can be carried out with good results and relatively low operative risks.

• 한국안전학회지
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• 제23권2호
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• pp.57-64
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• 2008

The Semiconductor industry in Korea has achieved a great contribution to the growth of its economy for the last 20 years with its product export ranked to #1 nowadays. However, the working environment in semiconductor industry is always exposed to a potential risk of critical safety issue for workers with many kinds of utilities used such as toxic chemicals, gases, high vacuum and high voltages of electricity. This study is focused on empirical research to find out the factors on safety climate and to examine the relationships of safety climate and safe work behaviour in the work site of Korea semiconductor industry. As a result of simulation, a strong positive relationships and safe work behaviour have been identified in this study. Its result and implications has been discussed and suggested further studies on its limitation from this study.

• Tuberculosis and Respiratory Diseases
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• 제78권3호
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• pp.149-155
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• 2015

Extracorporeal life support (ECLS) is a type of cardiopulmonary bypass. It is an artificial means of supplying oxygen and removing $CO_2$ on behalf of damaged lungs while patients are recovering from underlying diseases. Recently, the use of ECLS is rapidly increasing as this machine becomes smaller, less invasive and easier to use. In addition, the improvement of clinicians' technique and outcome is increasing their application to patients with acute respiratory distress. In this regard, the purpose of this review is to introduce the physiological principles, risk factors, and advantages of ECLS, clinical rationale for using ECLS, ventilatory strategy during ECLS, which are still causing different opinions, the weaning from ECLS, and the use of anticoagulant.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2011년도 추계 학술논문 발표대회
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• pp.151-152
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• 2011

As recent construction projects aim to build higher and bigger buildings, lifting operation is getting increasingly important in construction sites. Accordingly, as tower cranes get higher and higher, disasters involving tower cranes are also on the rise. According to occupational incident statistics of the Korea Occupational Health & Safety Agency (KOHSA), most of such incidents occur in installation, dismantling and climbing phases of tower crane. Therefore, it is essential to develop preventative measures to secure safety of tower crane operations, with critical focus on installation, dismantling and climbing of tower crane. Hence, this research attempts to measure criticality of key risk factors in installation, dismantling and climbing phases of tower crane on construction site and propose necessary safety measures. As a result, conclusions herein will contribute to minimize disasters and incidents involving tower cranes in high-rise building construction sites.