• 센서학회지
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• 제23권5호
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• pp.291-294
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• 2014

In this study, a chemiresistive sensor based on one-dimensional $WO_3$ nanostructures is presented for application in non-invasive medical diagnostics. $WO_3$ nanostructures were used as an active gas sensing layer and were deposited onto a $SiO_2/Si$substrate using Pt interdigitated electrodes (IDEs). The IDE spacing was $5{\mu}m$ and deposition was performed using RF sputter with glancing angle deposition mode. Pt IDEs fabricated by photolithography and dry etching. In comparison with thin film sensor, sensing performance of nanostructure sensor showed an enhanced response of more than 20 times when exposed to 50 ppm acetone at $400^{\circ}C$. Such a remarkable faster response can pave the way for a new generation of exhaled breath analyzers based on chemiresistive sensors which are less expensive, more reliable, and less complicated to be manufactured. Moreover, presented sensor technology has the potential of being used as a personalized medical diagnostics tool in the near future.

• 자동차안전학회지
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• 제7권4호
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• pp.9-15
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• 2015

The relationship between BAC(Blood Alcohol Concentrations) and BrACs(Breath Alcohol Concentrations) and also partition ratio of healthy Korean adult males (96 males) are researched in this paper and its dependency is described according to TBW (total body water), BMI (body mass index), BFM (body fat mass), and PBF (percentage of body fat). Among the above four variables, TBW affects significantly to the partition ratio compared to the other variables. The partition ratio of Korean healthy males showed 1,913 (95 % Confidence Interval (C.I.) from 1,889 to 1,937) for the whole time intervals. However, when Q was averaged after 60 minutes later, its values was 2,011 (95 % C.I. from 1,982 to 2,040). Bland-Altman plots showed the compatibility of measurement methods of multi-gas analyzer, and the biases according to the partition ratios (Q=2,100 and Q=1,913) gave -0.0052 % (95 % CI from -0.0059 to -0.0045%) and -0.0004 % (95 % CI from -0.0011 to +0.0003%), respectively.

• 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.

• 센서학회지
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• 제25권6호
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• pp.383-387
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• 2016

Well-ordered nanocolumnar indium oxide ($In_2O_3$) thin films have been successfully fabricated by glancing angle deposition (GAD) using an e-beam evaporator. Nanocolumnar structures have a porous and large surface area with a narrow neck between nanocolumns, which allows them to detect minute amounts of gases. The nanocolumnar $In_2O_3$ thin films were fabricated by the GAD process at five different positions, viz. top, bottom, center, left, and right in a four inch substrate holder. There was a divergence in the thickness and the base resistance of each sensor. However, all the sensors exhibited extremely high sensitivity that was greater than $10^3$ times the change in electrical resistance after being exposed to 50 ppm of acetone gas at $300^{\circ}C$. Furthermore, the nanocolumnar $In_2O_3$ sensors displayed an extremely low detection limit (1.2 ppb) in dry atmosphere as well as in high humidity (80%). We demonstrated that the GAD nanocolumnar $In_2O_3$ sensors have an enormous potential for many applications owing to their particularly simple and reliable fabrication process.

• 대한통합의학회지
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• 제9권1호
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• pp.183-192
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• 2021

Purpose : The purpose of this study was to investigate the impact of postural correction training on pulmonary function on 28 college students suspected of turtle neck syndrome, and the following conclusions were obtained. Methods : Turtle neck syndrome suspicion 28 person were randomly divided into a posture training group (n = 14) and group that does not perform posture training (n = 14). Respiratory function was measured by SPIROVIT SP-1 and respiratory gas analyzer. The posture training group performed balloon blowing and stair climbing after 20 minutes of posture training, and the group without posture training carried out balloon blowing training and stair climbing. Five times a week and for two weeks. Results : 1. The comparison of the FVC before and after experiments caused by balloon blowing showed a higher level of effortful pulmonary function in the control group than in the experimental group. 2. Comparison of PEFs before and after the experiment by balloon blowing showed that the experimental group's peak flow rate was higher than that of the control group. 3. Comparison of the FIVC before and after experiments with balloon blowing showed that the comparison of the FIVC showed a higher level of effortless intake pulmonary function in the control group than in the experimental group. 4. The comparison of the maximum ventilation volume(VE) before and after the experimental gas measurement showed that the maximum ventilation rate of the experimental group was higher than that of the control group. 5. The comparison of pre-test and post-test heart rate(HR) by breath gas measurement showed that the heart rate of the control group was higher than that of the experimental group. Conclusion : the results of this study showed that postural correction training, balloon blowing training, and stair climbing could have a positive impact on improving pulmonary function. However, the two-week experiment conducted five times a week showed an increase in pulmonary function, but it was difficult to see the effect due to the short study period. Therefore, it is hoped that later studies will be conducted more systematically on the effects of breathing exercises on improving pulmonary function after post-postural correction training for patients with pulmonary function problems.

• 생물정신의학
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• 제6권2호
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• pp.176-188
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• 1999

Objective : The purpose of this study was to evaluate the effects of alcohol on neurocognitive function, psychomotor performance and subjective response in healthy Korean adults with different ALDH2 genotypes. Method : A total of 24 males, half with active $ALDH2^*1/2^*1$ and the other with inactive $ALDH2^*1/2^*2$, was selected through genotyping using restriction fragment length polymorphism. In a double-blind, placebo-controlled cross-over design, each subject consumed 0.5g/kg dose of alcohol, given as a mixture of 40% vodka and orange juice, and placebo(orange juice) on two separate occasions on an average of weekly intervals. The blood alcohol concentrations(BACs) were measured using a breath analyzer at baseline and at 30, 60 minutes after drinking. P300s were measured at baseline and at 30 minutes after alcohol and placebo intake. Vital signs and psychomotor performance[Critical Flicker Fusion Threshold(CFFT), Choice Reaction Time (CRT), Digit Symbol Substitution(DSS)] were measured at baseline and at 60 minutes after alcohol and placebo intake. Subjective responses were measured at the end of the study. The statistical analysis focused on whether there were any differences between groups with different ALDH2 genotypes. Results : The major results are as follows. 1) BACs in the inactive group were overall equivalent to those in the active group. Only in terms of time, BACs were significantly higher overall at 30 minutes than at 60 minutes after alcohol intake. 2) Pulse rates were significantly increased after alcohol intake compared with placebo, and the increase was greater in the inactive than in the active group. 3) P300 latencies in leads Fz(frontal), Cz(cental) and Pz(parietal) were significantly increased after alcohol intake compared to placebo, and the increase was greater in the inactive than in the active group. P300 amplitudes in leads Cz and Pz were significantly decreased overall after alcohol intake compared to placebo. 4) Compared with placebo, alcohol produced significant effect on the psychomotor performance : impairment in the inactive group, improvement in the active group. 5) Compared with placebo, alcohol significantly induced a negative or an intense effect on the subjective responses in the inactive group, but little negative and even a somewhat positive effect in the active group. Conclusions : These results suggest that ALDH isozyme variance might be an important factor to determine the effects of acute dose of alcohol on the various psychobehavioural functions and also to determine the alcohol use pattern and to predict the future development of alcohol overuse and/or abuse.

• Journal of Preventive Medicine and Public Health
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• 제36권3호
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• pp.248-254
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• 2003

Objective : This study was conducted in order to investigate predictors of smoking cessation in outpatients. Method : Subjects were 40f adult smoking patients who saw their doctors in the outpatient setting at a university hospital, regardless of their willingness of otherwise in smoking cessation. Physicians delivered a brief, stop smoking prompt to all patients who smoked one or more cigarettes a day. Then they referred to on-site counselors who provided a brief, nurse assisted intervention with a survey to a randomly assigned intervention group (200 smoking patients), whom the counselors telephoned later to prevent relapse or promote the motivation to quit, or gave only a survey to a control group (201 smoking patients). After at least 5 months, self-reported current smoking cessation was confirmed later using cut-off values of 7 ppm or less in expired alveolar air after breath holding portable CO analyzer. Results : After 5 months, subjects in the intervention group were 1.56 times (95% C.I. 0.89-2.73) more likely to quit smoking than those in the non-intervention group (14.0% vs. 9.0%). Willingness to quit smoking in a month, scheduled admission in a month, self efficacy score and FTND (Fagerstrom Test for Nicotine Dependence) score were all significantly related with smoking cessation. In stepwise multiple logistic regression, previous attempts to quit smoking were significant instead of self efficacy score. In the intervention group who had willingness to quit smoking in a month (132 smoking patients), FTND score, whether quit date was today, and whether quit promise paper was submitting were all significantly related with smoking cessation. In stepwise multiple logistic regression, scheduled admission in a month and whether quit date was today were significant predictor variables, Smoking cessation treatment should be tailored to individual smoking patients considering these predictors.

• 한국표면공학회지
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• 제57권1호
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• pp.38-48
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• 2024

We fabricated In₂O₃ zig-zag nanocolumns(ZZNCs) by oblique angle deposition method based on e-beam evaporator for highly sensitive and selective CH₃COCH₃ sensor. Our results indicate that as the ZZNCs layer stacks, the gas response also increases. In comparison to thin films, ZZNCs at 5 layer show a 117-fold enhancement in gas response and a rapid response time (~2 s). When measured with various gases, it showed a high selectivity towards acetone. Under conditions of 80% R.H., exposure to CH₃COCH₃ gas theoretically indicated a detection limit of 1.2 part-per-billion(ppb). These results suggest the potential of In₂O₃ ZZNCs as a breath analyzer for the diagnosis of diabetes.

• 생물정신의학
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• 제3권2호
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• pp.222-239
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• 1996

ALDH-I 활성군과 비활성군에서 음주후 정신운동성 수행 및 주관적 평가에 미치는 영향을 비교하였다. 사교적 음주에 상응하는 4종류의 알콜(0.25, 0.5, 0.75, 1.0g/kg)을 투여한 결과 비활성군이 활성군에 비해 보다 부정적인 평가를 하였다. 이는 특히 고용량의 알콜(0.75 및 1.0g/kg)을 투여시 분명하였다. 이러한 결과는 비활성군이 활성군에 비해 알콜에 대한 민감성이 주관적인 판단과 객관적인 수행에서 모두 더 높다는 사실을 반영한다.