• Toxicological Research
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• 제26권4호
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• pp.329-337
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• 2010

Inhaled inorganic dusts, such as coal, can cause inflammation and fibrosis in the lungs, known as pneumoconiosis. Diagnosis of pneumoconiosis depends on morphological changes by radiological findings and functional change by pulmonary function test (PFT). Unfortunately, current diagnostic findings are limited only to lung fibrosis, which is usually irreversibly progressive. Therefore, it is important that research on potential and prospective biomarkers for pneumoconiosis should be conducted prior to initiation of irreversible radiological or functional changes in the lungs. Analytical techniques using exhaled breath condensate (EBC) or exhaled gas are non-invasive methods for detection of various respiratory diseases. The objective of this study is to investigate the relationship between inflammatory biomarkers, such as EBC pH or fractional exhaled nitric oxide ($FE_{NO}$), and pneumoconiosis among 120 retired coal miners (41 controls and 79 pneumoconiosis patients). Levels of EBC pH and FENO did not show a statistically significant difference between the pneumoconiosis patient group and pneumoconiosis patients with small opacity classified by International Labor Organization (ILO) classification. The mean concentration of $FE_{NO}$ in the low percentage $FEV_1$ (< 80%) was lower than that in the high percentage (80% $\leq$) (p = 0.023). The mean concentration of $FE_{NO}$ in current smokers was lower than that in non smokers (never or past smokers) (p = 0.027). Although there was no statistical significance, the levels of $FE_{NO}$ in smokers tended to decrease, compared with non smokers, regardless of pneumoconiosis. In conclusion, there was no significant relationship between the level of EBC pH or $FE_{NO}$ and radiological findings or PFT. The effects between exhaled biomarkers and pneumoconiosis progression, such as decreasing PFT and exacerbation of radiological findings, should be monitored.

• 동의생리병리학회지
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• 제35권6호
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• pp.249-254
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• 2021

The aim of this study was to raise awareness about smoking and to facilitate the induction of smoking cessation. The participants were 49 patients who showed intention to participate in the test. The participants who had done a questionnaire, were asked to quit smoking for about an hour. After taking the breath deeply, they stopped for 20 seconds and measured breathing slowly. Carbon monoxide in the exhalation was higher when the daily smoking amount was higher and the smoking duration was longer, but not significant. In the case of smoking after meal and smoking in bed in the morning, the carbon monoxide level was significantly higher than that in the case of not smoking. It was significantly associated with skin allergic symptoms. The usual exercise habits, drinking and the respiratory disease were not correlated with carbon monoxide levels.

• 문화기술의 융합
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• 제6권3호
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• pp.381-392
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• 2020

본 연구는 천연소재 12종의 페놀성 화합물 함량, 라디칼 소거능, 알코올탈수소효소(ADH), 아세트알데히드탈수소효소(ALDH) 활성도를 측정하고 상승효과를 가지도록 배합한 복합물의 숙취해소에 미치는 효과를 규명하는데 목적이 있다. 우수한 개별 소재를 선정하고 배합비를 달리하여 효능 평가를 통해, 배합비가 효능에 미치는 상관관계를 분석하였다. 8종의 추출물 중 보이차, 소나무, 갈근 순으로 ADH 활성이 높았고, 갈근은 배합량과 효능 간의 양의 상관관계, 보이차, 소나무 등은 음의 상관관계를 가지는 것으로 나타났다. 8종의 소재로 배합한 F1~F7 을 대상으로 ADH, ALDH 활성평가를 통해 F.7에서 상승효과가 가장 높은 것을 확인하여 최적 배합비로 도출하였다. F.7를 섭취한 시험군에서 알코올 섭취 30분 후부터 호기 알코올 농도가 섭취 직후 호기중 알코올 농도 대비 58%로 유의적으로 감소되기 시작하였고, 120분 후 27%로 호기중 알코올 농도가 감소되었다. 음주 후 발생하는 숙취증상 설문 결과 대조군에 비해 시험군에서 음주 후 발생하는 피곤함과 갈증에서 유의적인 개선효과 (p<0.05)가 있었다.

• 한국기계가공학회지
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• 제18권5호
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• pp.1-8
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• 2019

Breath analysis using a portable device is better than the classical breath analysis system in terms of installation and operation. There is an increasing need to develop cost-effective equipment for testing gas sensors from the viewpoint of functionalities that can be applied applicable to portable devices. In the present study, an economical gas chamber for in-situ gas measurement is implemented with a single gas chamber without using expensive gas storage and control equipment; the gas response characteristics are analyzed using the above-described chamber. The main features of the implemented gas chamber are simple injection procedure, improved gas diffusion, easy measurement and cleaning, support for low-power mode measurement function for portable devices, and open source platform. Moreover, an analysis of gas response characteristics based on changes in sensor voltage show that the sensitivity and 90% response time are affected by the sensor voltage. Furthermore, the sensitivity graph has an inflection point in a specific range. The gas sensor applied in this study showed fast response speed and high sensitivity for sensor voltages of 3.0-3.5 V, regardless of the concentration of acetone gas, the target gas used in this study.

• Journal of Periodontal and Implant Science
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• 제25권1호
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• pp.35-44
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• 1995

The purpose of present study was to evaluate the relationship between the early change of gingival condition and methyl mercaptan concentration during experimental gingivitis. Ten men(23-25 years old) whose gingiva were clinically healthy were selected. The participants have ceased to perform all forms of oral hygiene during 14 days and then did thorough plaque control for 7 days. For each subject, the methyl mercaptan concentration was measured by $B.B.Checker^{(R)}$ (Bad Breath Checker with printer, Tokuyama Soda Co.,LTD., Japan)before experiment and 1,4,7,14,21 days during experiment. Plaque index(Silness & $L\ddot{o}e$), gingival sulcus depth and sulcus bleeding index($M\ddot{u}hlemann$ & Son)score were recorded. The results were as follows. 1. Methyl mercaptan concentration increased continuously from the first day to the 14th day, decreased on the 21th day but it was still higher(P<0.001). 2. Plaque index score and sulcus bleeding index score tended to increase on the 4th day, markedly increased on the 14th day and returned to baseline level on the 21th day. 3. There was parallel relationhsip among methyl mercaptan concentration, plaque index score and sulcus bleeding index score. This result suggests that methyl mercaptan concentration increased with deterioration in gingival health, but decreased during recovery of normal health condition.

• 대한조선학회지
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• 제6권2호
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• pp.5-10
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• 1969

A stepped bar with seimi-circular stress relieving groove near the fillet was subjected by axial tension in a polarized light field. On the stress concentration factor, the effect of the ratios of the fillet radius, the distance between two relieving grooves and the groove radius to the breath of the narrower portion of the stepped bar have been investigate. Observing the stress concentration in 48 models with various proportions, the conclusion arrived at were as follow: 1) If the fillet radius of the stepped bar is larger than half breadth of the narrower portion, the reduction of the stress concentrations can not be expected. 2) If the fillet radius is smaller than half breadth of the narrower portion of the stepped bar, the stress concentration can be droped to the reasonable range. 3) When the groove radius is larger than a quarter of the difference between the distance of two relieving grooves and the breadth of the stepped bar and smaller than a half of that, the stress concentration factors can have their possible minimum value. 4) When the sun of the breadth of the narrower portion of the stepped bar and twice of the relieving groove radius is smaller than the distance between two relieving grooves, minimum stress concentration can be obtained.

• 한국산업보건학회지
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• 제24권3호
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• pp.321-329
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• 2014

Objectives: This study was performed to produce data on the pulmonary toxicity of neodymium oxide($Nd_2O_3$) by intratracheal instillation. Methods: Two groups of rats were exposed to neodymium oxide by intratracheal instillation with doses of 0.5 mg and 2.0 mg, respectively. At two days, four weeks and 12 weeks after exposure, body weight change, organ weight change and histopathological change were observed. At 12 weeks after exposure, lung function change was measured. Results: The body weight of rats in the high concentration group decreased after 12 weeks by 4-5% compared with the control group. At four weeks and 12 weeks after the administration of neodymium oxide, the absolute weight of the lungs of the high concentration group were significantly increased when compared with the control group(p<0.05). At 12 weeks after the injection of neodymium oxide, breath frequency and respiratory minute volume were increased, but inhalation time and expiratory time were decreased. Bronchiolar epithelial hyperplasia, alveolar type II cell hypertrophy/hyperplasia and foreign body granulomatous inflammation were observed in the high exposure group. Conclusions: Body weight decrease, lung absolute weight and breath frequency increase, and pathological lung change were all observed. We found that pulmonary toxicity of neodymium oxide nanoparticles by intratracheal instillation could be confirmed.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제48권9호
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• pp.676-680
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• 1999

To do breath alcohol measurement, a sensor is necessary that it can detect low alcohol gas concentration of 0.01% at least. In this work, a capacitance-type alcohol gas sensor using porous silicon layer is developed to measure low alcohol gas concentration. The sensor using porous silicon layer has some sensitivity at room temperature by very large effective surface area, but there is still much room for improvement. In this experiment, we measured the capacitance of the sensor under 254 nm UV light on the porous silicon layer, in which alcohol solution was kept in a flask at 25, 35, and $45^{\circ}C$ by a heater. As the result, the improvement of sensitivity by illuminating UV light was observed. The increasing rate of the capacitance was shown to be double more than those measured under UV-off state. It is supposed that UV light activates response of the oriental and interfacial polarizations which have slow relaxation time for AC field.

• 대한지역사회영양학회지
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• 제6권1호
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• pp.28-35
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• 2001

This study was designed to assess the iron nutritional status and anemia of high school students. 383 female subjects in Ulsan Metropolitan city were evaluated using a questionnaire, and a measurement of hematological indices. The average height and weight of the respondents were 161.24$\pm$4.90 cm and 53.12$\pm$6.37kg, repectively. The average BMI(body mass index) was 20.43$\pm$2.26 which was in the normal ramge. The average hemoglobin(Hb) concentration of the subjects was 13.14$\pm$0.97g/dl, and the average hematocrit(Hct) level was 40.84$\pm$17.40%. Transferrin saturation{TS(%)} was 20.86$\pm$10.32%, and the ferritin by Hct(＜36%), 27.2%by TS(＜14%),26.6% by ferritin(＜12 ng/ml). As for clinical symptoms, the greatest number of respondents reported that they experienced ‘decreased ability to concectrate’. Mean daily intakes of iron were 14.89$\pm$4.48 mg and heme iron intakes were 5.04$\pm$2.13 mg, which was 29.6% of total iron intake. The total iron binding capacity(TIBC) was negatively correlated with Hb concentration(r= -0.222, p＜0.01). Serum ferritin was positively correlated with Hb concentration(r= - 0.323, p＜0.05) and negatively correlated with TIBC(r= -0.367, p＜0.01). TS(%) was positively correlated with Hb concentration(r= 0.402, p＜0.01) and positively correlated with serum ferritin(r=0.413, p＜0.01). As for the correlation between blood biochemistry and clinical symptoms related to anemia, the Hb concentration was negatively correlated with ‘shortening of breath when going upstairs(p＞0.05)’ and ‘cold hands and feet’ significantly(r= -0.109, p＜0.05). The level of Mean corpuscular volume(MCV) was negatively correlated with ‘feel dizzy when standing up’,‘tired out easily’, and ‘decrease ability to concentrate’ significantly(p＜0.05). In particular, the level of Fe was negatively correlated with ‘shortening of breath when going upstairs’ and ‘feeling blue’ significantly(p＜0.01). These results suggest That the prevalence of iron deficiency of female high school students is very high, therefore guidelines for diet supports and nutrition education to improve their iron status should be provided.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2009년도 정보 및 제어 심포지움 논문집
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• pp.347-349
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• 2009

Air quality of indoor space environment is affected by various pollutants like as particles and chemical stuffs. The indoor air pollution affects directly the human respiration organs to cause consequently unpleasant mental status. The $CO_2$ concentration level is one of the harmful components of air pollutants. Major factor to increase the $CO_2$ concentration level is the people's breath amount in indoor. The car exhaust gas diffused from the around road also has strong affect on $CO_2$ concentration. There are some other reasons to affect the $CO_2$ concentration change, such as, real-time change of the population movement, closeness to the indoor air flow inlet window and changes in road car traffic amount. A remote monitoring system to measure environmental indoor air pollution concerning on the $CO_2$ concentration was studied and installed realized set-up model. Zigbee network configuration was applied for this system and the $CO_2$ concentration data were collected through USN network. A software program was developed to assure systematic analysis and to display real-time data on web pages. For the experimental test various condition was set up, like as, window opening, stopping air condition operation and adjusting fan heater work, etc. The analysis result showed the relation of various environmental conditions to $CO_2$ concentration changes. The causes to increase $CO_2$ concentration were experimentally defined as windows closing, the stopping air condition system, fan heater operation. To keep the $CO_2$ concentration under the legally required ppm level in public access indoor space, the developed remote measurement system will be usefully applied.