• 센서학회지
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• 제27권5호
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• pp.345-351
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• 2018

We employed an unprecedented technique to synthesize porous $WO_3@SnO_2$ nanofibers exhibiting core-shell and fiber-in-tube configurations. Firstly, 2-methylimidazole was uniformly incorporated in as-spun nanofibers containing ammonium metatungstate hydrate and the sacrificial polymer (polyacrylonitrile). Secondly, the 2-methylimidazole on the surfaces of nanofibers was complexed with tin(II) chloride ($SnCl_2$) via simple impregnation of the as-spun nanofibers in ethanol containing tin(II) chloride dihydrate ($SnCl_2{\cdot}2H_2O$). The presence of vacant p-orbitals in tin (Sn) and the nucleophilic nitrogen on the imidazole ring allowed for the reaction between $SnCl_2$ and 2-methylimidazole, forming adducts on the surfaces of the as-spun nanofibers. The calcination of these nanofibers resulted in porous $WO_3@SnO_2$ nanofibers with a higher surface area ($55.3m^2{\cdot}g^{-1}$) and a better response to 1-5 ppm of acetone than pristine $SnO_2$ NFs synthesized using a similar method. An improved response to acetone was achieved upon functionalization of the $WO_3@SnO_2$ nanofibers with catalytic palladium nanoparticles. This work demonstrates the potential application of $WO_3@SnO_2$ nanofibers as sensing layers for chemiresistive sensory devices for the detection of acetone in exhaled breath.

• 센서학회지
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• 제25권3호
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• pp.223-228
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• 2016

In this work, we prepared porous WO3 nanofibers (NFs) functionalized by bio-inspired catalytic $Cr_2O_3$ and $Co_3O_4$ nanoparticles as highly sensitive and selective $H_2S$ gas sensing layers. Highly porous 3-dimensional (3D) NFs networks decorated by well-dispersed catalyst NPs exhibited superior $H_2S$ gas response ($R_{air}/R_{gas}$ = 46 at 5 ppm) in high humidity environment (95 %RH). In particular, the sensors showed outstanding $H_2S$ selectivity against other interfering analytes (such as acetone, toluene, CO, $H_2$, ethanol). Exhaled breath sensors using $Cr_2O_3$ and $Co_3O_4$ catalysts-loaded $WO_3$ NFs are highly promising for the accurate detection of halitosis.

• 한국산업보건학회지
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• 제29권3호
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• pp.404-413
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• 2019

Objectives: Chronic obstructive pulmonary disease(COPD) is an important cause of mortality in workers exposed to hazardous dust, such as crystalline silica or coal, and COPD is related to inflammation and oxidative stress in the lung. The aim of this study was to evaluate the association of oxidative stress and inflammation to COPD in retired workers exposed to mineral dust. Methods: The levels of malondialdehyde(MDA) in EBC as biomarkers for oxidative stress and C-reactive protein(CRP) and lactate dehydrogenase(LD) as biomarkers for inflammation were measured in 107 male subjects(63 pneumoconiosis and 42 COPD subjects). Results: Mean levels of EBC MDA(2.03 nmol/L vs. 4.65 nmol/L, p=0.010) and serum LD(170.3 U/L vs. 185.9 U/L, p=0.022) were significantly higher in subjects with COPD, but mean levels of serum CRP(p=0.469) did not show a statistical difference between the study groups. Level of EBC MDA was negatively correlated with ${%}FEV_1$ predicted(r=-0.279, p=0.004) and ${%}FEV_1/FVC$ ratio(r=-0.397, p<0.001). Conclusions: These results suggest that EBC is a useful biological matrix for investigation of respiratory oxidative stress. High levels of EBC MDA and serum LD are related to COPD in retired workers exposed to mineral dust.

• 한국환경과학회지
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• 제4권3호
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• pp.277-284
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• 1995

일반 가정의 염소 처리된 수소수 사용과 관련되 클로로포롬 노풀을 확인 할 필요성에 대한 관심이 증가하고 있다. 삼십분 동안의 정상적인 목욕이 아파트의 한 욕실에서 두명의 자원자에 의해서 10차례 행해졌다. 클로로포름 농도가 물과 욕실 공기 및 목욕 전후에 피실험자의 호기로부터 측정되었다. 염소처리 수도수를 사용하여 목욕을 했을 \ulcorner\ulcorner 클로로포름에 대한 노출이 일어났고, 인체 부담도 야기되었다. 목욕 전후에 채취된 호기 시료의 농도차에 기초하여. 한번의 30분 목욕으로 부터 야기되는 클로로포름에 대한 인체부담은 목욕전에 비하여 8배 내지 26배가 되는 것으로 산정 되었다. 이와같은 인체부담을 설명하기 위해서 측정된 물과 욕실공기내의 클로로포름 농도는 각각 $9.4\mu\textrm{g}/l$ 및 $14.9\mu\textrm{g}/m^3$ 이었다. 이러한 욕셀 공기내의 클로로포름 농도는 거실공기 보다 34배 내지 130배 가량 높게 나타났다. 욕실공기와 해당 호기에서의 클로로포름의 농도 관계는 p=0.03 와 $R^2=0.47$의 조건에서 유의성이 있는 것으로 나타났다.

• 한국환경과학회지
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• 제4권3호
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• pp.125-125
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• 1995

일반 가정의 염소 처리된 수소수 사용과 관련되 클로로포롬 노풀을 확인 할 필요성에 대한 관심이 증가하고 있다. 삼십분 동안의 정상적인 목욕이 아파트의 한 욕실에서 두명의 자원자에 의해서 10차례 행해졌다. 클로로포름 농도가 물과 욕실 공기 및 목욕 전후에 피실험자의 호기로부터 측정되었다. 염소처리 수도수를 사용하여 목욕을 했을 ?? 클로로포름에 대한 노출이 일어났고, 인체 부담도 야기되었다. 목욕 전후에 채취된 호기 시료의 농도차에 기초하여. 한번의 30분 목욕으로 부터 야기되는 클로로포름에 대한 인체부담은 목욕전에 비하여 8배 내지 26배가 되는 것으로 산정 되었다. 이와같은 인체부담을 설명하기 위해서 측정된 물과 욕실공기내의 클로로포름 농도는 각각 $9.4\mu\textrm{g}/l$ 및 $14.9\mu\textrm{g}/m^3$ 이었다. 이러한 욕셀 공기내의 클로로포름 농도는 거실공기 보다 34배 내지 130배 가량 높게 나타났다. 욕실공기와 해당 호기에서의 클로로포름의 농도 관계는 p=0.03 와 $R^2=0.47$의 조건에서 유의성이 있는 것으로 나타났다.

• 한국표면공학회지
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• 제56권6호
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• pp.393-400
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• 2023

Acetone, a metabolite detected from the exhaled breath of people doing a diet, can be used for non-invasive monitoring of diet efficiency. Thus, gas sensors with rapid response and recovery characteristics to acetone need to be developed. Herein, we report ultrafast acetone sensors using Ce-doped In₂O₃ nanoparticles prepared by the one-pot microwave-assisted hydrothermal method. The pure In₂O₃ sensor shows a high response and fast response time (τ_res = 6 s) upon exposure to 2 ppm acetone at 300 ℃, while exhibiting a relatively sluggish recovery speed (τ_recov = 1129 s). When 20 wt% Ce is doped, the τ_recov of the sensor significantly decreased to 45 s withholding the fast-responding characteristic (τ_res = 6 s). In addition, the acetone response (resistance ratio, S) of the sensor is as high as 5.8, sufficiently high to detect breath acetone. Moreover, the sensor shows similar acetone sensing characteristics even under a highly humid condition (relative humidity of 60%) in terms of τ_res (6 s), τ_recov (47 s), and S (4.7), demonstrating its high potential in real applications. The excellent acetone sensing characteristics of Ce-doped In₂O₃ nanoparticles are discussed in terms of their size, composition, phase, and oxygen adsorption on the sensing surface.

• Journal of Digestive Cancer Research
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• 제4권2호
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• pp.107-112
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• 2016

Gastric cancer is the fifth most common malignancy in the world and still remains the third and fifth leading cause of cancer death in male and female, respectively. In terms of the cancer survival, the survival of gastric cancer is low in the West with showed 5-year survival rates of 10-30%, whereas the survival rates in Asia is more than 50%. The reason of the higher survival rate from gastric cancer in Asia partially related with the availability of gastric cancer screening programs, however, the population-based screening for gastric cancer has been conducted just in Korea and Japan. Therefore, more effective method for detecting the gastric cancer is needed for countries without a population-based gastric cancer screening. Endoscopy is the most effective method for diagnosis of gastric cancer however, it requires a large infrastructure including a large number of endoscopic equipment and well-trained endoscopists. To overcome these problems, several noninvasive methods (such as serologic markers, biomarkers, cancer autoantibodies, and exhaled breath analysis) for diagnosis of gastric cancer screening are suggested. This review addresses the conventional methods and the emerging methods for gastric cancer screening.

• 한국보건간호학회지
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• 제19권1호
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• pp.74-94
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• 2005

The purpose of this study was to compare the effect of education between CAI(Computer Assisted Instruction) and lectures for smoking cessation among male students who attended vocational high schools. Conducted from February 24th to April 26th, 2003, the study design was quasi-experimental with nonequivalent control group pretest-posttest design. The study subjects were 60 male students in K vocational high school in Daegu city, who were present smokers and had more than 7.0 ppm concentration level of carbon monoxide. Thirty students were randomly chosen as the experimental group which applied CAI education method for smoking cessation. The other 30 students served as the control group which received lecture education method of 40 minutes on four consecutive days. CAI education for smoking cessation was composed of ready-made individual learning contents, counseling by using cyber-communication, writing a letter to stop smoking, and writing a written agreement for smoking cessation. Lecture education for smoking cessation was composed of a ready-prepared lecture for the group, writing a letter to stop smoking, and writing a written agreement for smoking cessation. To measure smoking related knowledge, Jeong Ree Roh(1996)'s smoking related knowledge scale$(Cronbach's\;{\alpha}=0.84)$ was modified and used by the researcher. To measure smoking related attitude, Jeong Ree Roh(1996)'s smoking related attitude scale$(Cronbach's\;{\alpha}=0.91)$ was modified and used by the researcher. Smoking related knowledge scale's Cronbach's $\alpha$ was 0.83 in the pilot study and 0.93 in this study. Smoking related attitude scale's Cronbach's a was 0.80 in the pilot study and 0.98 in this study. To determine the smoking amount, the number of cigarettes smoked per day was checked. The concentration level of CO in the exhaled breath was measured (Micro CO Cat. No. MCO2, UK). Data was analyzed by $x^2-test$, t-test, repeated measures ANOVA. simple main effects, and time contrast test with SPSS/Win 11.0 program. The results of this study were as follows: 1. The first hypothesis. that 'Smoking-related knowledge score in the experimental group by using CAI education for smoking cessation will be higher than that in the control group by using lecture education for smoking cessation', was not supported. 2. The second hypothesis, that 'Smoking-related attitude in the experimental group by using CAI education for smoking cessation will be higher than that in the control group by using lecture education for smoking cessation'. was supported(F=6490.79. p=0.000). 3. The third hypothesis. that 'Smoking amount in the experimental group by using CAI education for smoking cessation will be less than that in the control group by using lecture education for smoking cessation'. was supported. 1) The third-1st sub-hypothesis. that 'The number of cigarettes smoked per day in the experimental group by using CAI education for smoking cessation will be less than that in the control group by using lecture education for smoking cessation'. was supported(F=134.19. p=0.000). 2) The third-2nd sub-hypothesis. that 'The concentration level of CO by ppm per one exhaled breath in the experimental group by using CAI education for smoking cessation will be lower than that in the control group by using lecture education for smoking cessation"' was supported(F=268.55. p=0.000). From the above results. CAI education can be an effective intervention to improve smoking-related knowledge and attitude. and to reduce the number of cigarettes smoked per day and the concentration level of CO by ppm per one exhaled breath. Lecture education can be effective to improve smoking-related knowledge. In the future, when CAI education and lecture education for smoking cessation are applied on the school nursing field. the students can gain a comprehensive understanding of smoking cessation, changes in smoking-related knowledge. smoking-related attitude and reducing smoking amount. Furthermore, CAI education for smoking cessation could be developed as an individual self initiative program and could give a guideline to apply CAI education for smoking cessation in other field.

• 대한핵의학회지
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• 제39권1호
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• pp.21-25
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• 2005

목적: $^{14}C$-요소호기검사(UBT)는 Helicobacter pylori (H. pylori) 감염을 진단하는데 비침습적이고 유용한 방법으로 알려져 있다. 그러나 기존의 $^{14}C$-UBT는 액체 섬광계수기(LS)를 이용하여 측정하므로 검사과정이 복잡하고 시간이 많이 걸리는 단점이 있다. 저자들은 동일한 환자에서 최근에 개발되어 간편해진 $Geiger-M\ddot{u}ller$계수기(GM)를 이용한 측정과 기존의 LS를 이용한 측정을 시행하여 진단성능을 비교하여 GM을 이용한 방법이 기존의 LS를 이용한 방법을 대체할 수 있는지를 알아보고자 하였다. 대상 및 방법: 상부위장관 증상이 있어 일주일 이내에 위십이지장 내시경, LS와 GM을 이용한 $^{14}C$-UBT가 모두 시행된 49명(M:F=30:19, 나이 $41{\pm}14$ yrs)을 대상으로 하였다. 모든 환자에서 최소 6시간 금식을 한 후 37 KBq의 $^{14}C$-urea 캡슐을 복용한 후 LS 와 GM 측정법에 따른 호기 샘플을 얻어 각각 측정하였다. 위십이장 내시경시 시행된 조직 검사 결과를 금과옥조로 H. pylori 감염에 대한 두 계수측정 방법의 진단성능을 비교하였고, 두 측정법의 일치 정도와 측정값 사이의 상관관계를 알아보았다. 결과: 49명중 조직검사를 시행받은 사람은 18명이었으며 이중 H. pylori 감염은 13명(72.2%)에서 관찰되었고 LS와 GM 측정법은 모두 동일한 결과를 보여 민감도 100%, 특이도 100%, 정확도 100%를 보였다. 49명의 대상 환자 전체에서 시행된 두 계수측정법의 일치율은 98%(48/49)이었으며 불일치률은 2% (1/49)였다. LS와 GM에 의한 측정값은 통계학적으로 유의한 상관관계 (r=0.859, p<0.001)를 보였다. 결론: GM을 이용한 $^{14}C$-UBT는 LS 측정법과 동일한 진단성능을 보여, 보다 간편하고 빠른 검사법으로 LS측정법을 대체하여 임상적으로 유용하게 이용될 수 있을 것으로 생각된다.

• The Korean Journal of Physiology
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• 제11권2호
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• pp.45-50
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• 1977

The maximum voluntary ventilation (MVV) is one of the most widely used pulmonary function test, but its measuring method was very difficult and unreliable. However, it is need to get more easy and simple measuring method of MVV. Therefore, this study was attempted to get more easy and simple measuring method of MVV by means of the forced expiratory volume $(FEV_{T})$. The young and healthy 1,000 Korean students(592 male and 408 female) were cheesed for this purpose and whose ages were from 8 to 20 years. A spirometer (9L, Collins Co.) was used for the MVV and FEV, and they were measured 3 times at standing position, and the highest value was used. In the measurements, the subjects for MVV were asked for the breath as fast and deeply as possible for 12 seconds, and for FEV were asked for the rapid and forceful exhalation after a maximal inhalation (forced expiratory curve). In the FEV measurements toward the end of the expiration, the subjects were exhaused to continue the effort until no further gas was expired. During these measurements, the investigator stood by the subject to give a constant encouragement. FEV were calculated in the volume exhaled during the one-half $(FEV_{0{\cdot}5,}\;ml)$, the first second $(FEV_{1{\cdot}0,}\;ml)$ and the percentage of the total vital capacity exhaled during the one-half second $(FEV_{0{\cdot}5,}\;%)$. The results are summarized as follows: 1) The values of MVV were increased linearly with ages until 20 in both sexes. The values of male at the age of 20 was $168.2{\pm}2.5L/min$, and female at the age of 17 was $112.3{\pm}3.0L/min$, respectively. 2) The values of FEV (ml) were increased linearly with ages until 20 in both sexes. The values of $FEV_{0{\cdot}5}$ were $2,797{\pm}65.7ml$ in the male of 20 years and were $2,088{\pm}54.6ml$ in the female of 17 years, and of $FEV_{1{\cdot}0$ were $4,119{\pm}68.2ml$ in the male of 20 years and were $2,897{\pm}65.9ml$ in the female of 17 years, respectively. 3) The correlation coefficients between MVV and $FEV_{0{\cdot}5}\;or\;FEV_{1{\cdot}0$ (ml) were 0.82 or 0.85 in the male, and 0.77 or 0.79 in the female, respectively. 4) The prediction formulae for MVV to be derived from above results were: For male: MVV (L/min) =7.19+$0.05{\times}FEV_{0\cdot5}(ml)$, MVV (L/min)=11.25+$0.04{\times}FEV_{1\cdot0}(ml)$ For female: MVV (L/min)=16.03+$0.05{\times}FEV_{0\cdot5}(ml)$, MVV (L/min)=9.47+$0.03{\times}FEV_{1\cdot0}(ml)$.