• Tuberculosis and Respiratory Diseases
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• 제78권1호
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• pp.8-17
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• 2015

Background: AMP-activated protein kinase (AMPK) not only functions as an intracellular energy sensor and regulator, but is also a general sensor of oxidative stress. Furthermore, there is recent evidence that it participates in limiting acute inflammatory reactions, apoptosis and cellular senescence. Thus, it may oppose the development of chronic obstructive pulmonary disease. Methods: To investigate the role of AMPK in cigarette smoke-induced lung inflammation and emphysema we first compared cigarette smoking and polyinosinic-polycytidylic acid [poly(I:C)]-induced lung inflammation and emphysema in $AMPK{\alpha}1$-deficient ($AMPK{\alpha}1$-HT) mice and wild-type mice of the same genetic background. We then investigated the role of AMPK in the induction of interleukin-8 (IL-8) by cigarette smoke extract (CSE) in A549 cells. Results: Cigarette smoking and poly(I:C)-induced lung inflammation and emphysema were elevated in $AMPK{\alpha}1$-HT compared to wild-type mice. CSE increased AMPK activation in a CSE concentration- and time-dependent manner. 5-Aminoimidazole-4-carboxamide-1-${\beta}$-4-ribofuranoside (AICAR), an AMPK activator, decreased CSE-induced IL-8 production while Compound C, an AMPK inhibitor, increased it, as did pretreatment with an $AMPK{\alpha}1$-specific small interfering RNA. Conclusion: $AMPK{\alpha}1$-deficient mice have increased susceptibility to lung inflammation and emphysema when exposed to cigarette smoke, and AMPK appears to reduce lung inflammation and emphysema by lowering IL-8 production.

• Advances in environmental research
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• 제6권3호
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• pp.189-202
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• 2017

This study examines the concentrations of particulate-phase polycyclic aromatic hydrocarbons (PAHs) and gas-phase PAHs in sidestream cigarette smoke. Sixteen PAHs were determined for four brands of cigarettes. The volume of the experimental room is approximately $66m^3$. The air samples in the room were collected before and after smoking. The median total of particulate-phase and gas-phase PAH concentrations before smoking $3.13ng/m^3$and $48.0ng/m^3$, respectively. The median concentrations of them after smoking were $10.0ng/m^3$ and $79.6ng/m^3$. The median increases in the total of 16 PAH concentrations per cigarette during smoking were 271 ng for the particulate-phase PAHs and 1960 ng for the gas-phase PAHs. According to the relationship between particulate-phase and gas-phase PAHs after smoking, the two- to four-ring gas-phase PAHs and the higher molecular weight particulate-phase PAHs were probably formed from similar precursors. The relationship between the total suspended particulate (TSP) concentration and the increase in the total particulate-phase concentration of the 16 PAHs per cigarette during smoking were significantly positive. The increase in the total gas-phase concentration of the 16 PAHs tended to increase as the TSP concentration increased. This may indicates that decreasing the amount of TSP produced inhibit the production of PAHs during smoking.

• Journal of the Korean Wood Science and Technology
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• 제43권2호
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• pp.258-264
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• 2015

To evaluate the influence of 3A zeolite on the flame retardant properties of poplar plywood. Ammonium polyphosphate (APP) and 3A zeolite were used as flame retardants to prepare plywood samples. The combustion properties, such as heat release rate (HRR), total heat release (THR), mean CO and $CO_2$ yield, smoke production rate (SPR), and total smoke production (TSP), were characterized by a cone calorimeter. A synergistic effect was observed between 3A zeolite and APP on reducing the HRR and mean CO yield. The probable flame retardation mechanism was proposed.

• 한국안전학회지
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• 제37권4호
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• pp.73-79
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• 2022

In this study, real fire tests were performed on representative combustibles of residential facilities to analyze the fire behavior and combustion characteristics in a small residential space. The considered combustibles were a sofa, a combination of a desk and a chair, and a combination of a mattress and an electric mat. A compartment space fire test was performed using the room corner test equipment prescribed in the KS F ISO 9705 specification. Three real fire tests were conducted by placing the combustible material inside a small compartment with insulation and finishing materials and by igniting the combustible material. Results showed that the peak heat release rate and peak smoke production rate occurred in the combination of the mattress and electric mat. Furthermore, from the result of the fire rate analysis, it was estimated that the fire risk of the mattress and electric mat combination was the highest, followed by the sofa and thedesk and chair combination.

• 공업화학
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• 제24권6호
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• pp.616-620
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• 2013

본 연구에서는 자원 재활용-에너지에 바탕을 둔 돈분, 계분, 혼합물의 연소특성에 대하여 고찰하였다. 시험편은 건조 오븐을 이용하여 항량까지 건조시킨 후에, 콘칼로리미터(ISO 5660-1)를 이용하여 연소성질을 시험하였다. 그 결과 돈분의 최대유효연소열(78.72 MJ/kg)은 계분(69.41 MJ/kg)과 비교하여 탄화수소의 많은 양 때문에 비교적 증가했다. 또한 돈분의 $CO_2$ 발생속도(0.1959 g/s)와 총연기발생률($419m^2/m^2$)도 각각에 대하여 계분보다 증가하였다. 반면에 계분의 CO 발생량(0.0996 kg/kg)과 CO 발생속도(0.0034 g/s)는 계분이 함유하고 있는 많은 무기물 함량 때문에 각각 돈분보다 높았다. 따라서 높은 연소 에너지는 탄화수소 함량에 의존하여 발생되는 것으로 판단된다.

• 한국대기환경학회지
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• 제25권3호
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• pp.237-247
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• 2009

The combustion characteristics of car components have been investigated, The combustion parameters like heat release rate, smoke production, yield of carbon dioxide and carbon monoxide and mass loss rate were analyzed by cone-calorimeter for representative samples (seat, carpet, headrest, rubber mat, dash board and electric wire) collected from a used car. The results from sample combustion showed that cover and sponge in seat more quickly ignited and flamed than other parts. The heat released from the combustion of dash board sample was 144.29$kw/m^2$ and the smoke produced by the wire combustion was 6896.4 $m^2/m^2$. The yields of carbon dioxide and carbon monoxide were in the ranges of 1.09${\sim}$2.76 kg/kg and 0.0262${\sim}$0.1008 kg/kg, respectively.

• 한국안전학회지
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• 제32권5호
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• pp.20-24
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• 2017

In this study, we have performed the Cone Calorimeter test in accordance with ISO 5660-1 to check the combustion characteristics of building flooring materials. The fire risk of these materials were evaluated by construction code, KFI criteria and standards of flame retardant performance. When samples exposed to external heat flux, all samples consumed a lot of Oxygen for a long time. So heat release from sample burning continued so long. And also all samples produced so much smoke. Even though a few samples were satisfied with only peak heat release rate criteria, all 8 samples were not satisfied with criteria of peak heat release rate and total heat released together. The results of 5 min total heat released were $15.9MJ/m^2{\sim}5.9MJ/m^2$. It menas the results are more than 2~6 times higher than the criteria. The results of 10 min total heat released were $30.1MJ/m^2{\sim}100.8MJ/m^2$. It means the results are more than 3~12 times higher than the criteria. 6 of 8 samples were not satisfied with Dm.corr.(corrected maximum smoke density) criteria. The building flooring materials which we used for this test ignited very fast and the burning continued so long. It means these samples are susceptible to fire.

• Experimental and Molecular Medicine
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• 제50권11호
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• pp.9.1-9.10
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• 2018

Although the positive effects of recombinant fibroblast growth factor-2 (rFGF-2) in chronic obstructive pulmonary disease (COPD) have been implicated in previous studies, knowledge of its role in COPD remains limited. The mechanism of FGF2 in a COPD mouse model and the therapeutic potential of rFGF-2 were investigated in COPD. The mechanism and protective effects of rFGF-2 were evaluated in cigarette smoke-exposed or elastase-induced COPD animal models. Inflammation was assessed in alveolar cells and lung tissues from mice. FGF-2 was decreased in the lungs of cigarette smoke-exposed mice. Intranasal use of rFGF-2 significantly reduced macrophage-dominant inflammation and alveolar destruction in the lungs. In the elastase-induced emphysema model, rFGF-2 improved regeneration of the lungs. In humans, plasma FGF-2 was decreased significantly in COPD compared with normal subjects (10 subjects, P = 0.037). The safety and efficacy of inhaled rFGF-2 use was examined in COPD patients, along with changes in respiratory symptoms and pulmonary function. A 2-week treatment with inhaled rFGF-2 in COPD (n = 6) resulted in significantly improved respiratory symptoms compared with baseline levels (P < 0.05); however, the results were not significant compared with the placebo. The pulmonary function test results of COPD improved numerically compared with those in the placebo, but the difference was not statistically significant. No serious adverse events occurred during treatment with inhaled rFGF-2. The loss of FGF-2 production is an important mechanism in the development of COPD. Inhaling rFGF-2 may be a new therapeutic option for patients with COPD because rFGF-2 decreases inflammation in lungs exposed to cigarette smoke.

• 한국화재소방학회논문지
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• 제26권5호
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• pp.41-47
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• 2012

첨단산업기술인 반도체, LCD 등 제조의 핵심공정인 클린룸은 생산제품의 성능 및 품질에 절대적인 영향을 미치는 가장 중요한 공정이다. 그러나 국내는 방화공학적인 측면에서 과학적이고 종합안전대책에 대한 체계적인 연구가 제대로 이루어지지 않고 있다. 본 연구는 LCD 제조공정 클린룸에 설치하는 제연시스템의 성능 및 문제점을 파악하여 이에 대한 개선방안을 도출하기 위하여 여러 시나리오를 고려한 화재시뮬레이션과 피난시뮬레이션을 통하여 분석하였다. LCD 제조공정의 클린룸 화재 및 연기확산에 대하여 분석한 결과 화재시 공조기의 연동정지는 반드시 필요하며 연기의 부력을 고려하여 FAB 상부에 배연을 할 수 있도록 하여야 한다. 또한 대규모 클린룸의 경우 화재특성상 스프링클러헤드의 집열 성능이 떨어지므로, 조기반응형 헤드의 설치 및 작동시간을 빠르게 하기 위한 보조장치를 설치하여야 한다. 특히, 대공간 클린룸은 자동화 공정으로 거주밀도가 낮지만, 복잡한 생산장비의 배치와 방진복을 착용하고 근무해야하는 환경특성 때문에 화재시 피난안전성능 확보가 어렵기 때문에 공정 내 위험요소의 철저한 관리 및 주기적인 교육과 훈련이 필요하며, 방재선진국의 기준에 준하는 수준의 국내 관련기술 기준을 정립할 필요가 있다.

• Journal of Microbiology and Biotechnology
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• 제33권5호
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• pp.634-643
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• 2023

Chronic obstructive pulmonary disease (COPD), one of the leading causes of death worldwide, is caused by repeated exposure to harmful matter, such as cigarette smoke. Although Lilium longiflorum Thunb (LLT) has anti-inflammatory effects, there is no report on the fermented LLT bulb extract regulating lung inflammation in COPD. Thus, we investigated the protective effect of LLT bulb extract fermented with Lactobacillus acidophilus 803 in COPD mouse models induced by cigarette smoke extract (CSE) and porcine pancreas elastase (PPE). Oral administration of the fermented product (LS803) suppressed the production of inflammatory mediators and the infiltration of immune cells involving neutrophils and macrophages, resulting in protective effects against lung damage. In addition, LS803 inhibited CSE- and LPS-induced IL-6 and IL-8 production in airway epithelial H292 cells as well as suppressed PMA-induced formation of neutrophil extracellular traps in HL-60 cells. In particular, LS803 significantly repressed the elevated IL-6 and MIP-2 production after CSE and LPS stimulation by suppressing the activity of the nuclear factor kappa-light-chain-enhancer of activated B (NFκB) in mouse peritoneal macrophages. Therefore, our results suggest that the fermented product LS803 is effective in preventing and alleviating lung inflammation.