• The Korean Journal of Physiology
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• 제27권2호
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• pp.209-215
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• 1993

The aim of the present study was to derive regression equations for $\dot{V}o_{2max}\;vs.\;\dot{V}o_{2peak},\;and\;\dot{V}o_2\;vs.$ heart rate, exercise time, and other variables from maximal exercise tests on a treadmill using the Bruce and inclined protocols. Twelve male and 10 female Korean college students aged between 19 and 23 years voIunteered for this study. After the resting measurements, the subjects performed a maximal exercise on a treadmill according to the Bruce protocol. When the resting conditions were restored, the subjects performed another maximal exercise according to an inclined protocol where the speed was fixed at 8.05 $km{\cdot}h^{-1}$ and the grade was incremented starting from 09t by 2.5% for every 2 min. Peak $\dot{V}o_2$ observed during the Bruce exercise $(\dot{V}o_{2peak})$ was $37.7{\pm}2.4\;and\;31.7{\pm}1.8\;ml\;kg^{-1}\;min^{-1}$ in the male and female groups, respectively. Peak $\dot{V}o_2$ observed during the inclined exercise was higher than $\dot{V}o_{2peak}$ during the Bruce exercise. Maximum $\dot{V}o_2$ value observed during the tyro exercises $(\dot{V}o_{2max})$ was $43.0{\pm}2.8\;and\;36.2{\pm}1.4\;ml\;kg^{-1}\;min^{-1}$ in the male and female groups, respectively. Thus, $\dot{V}o_{2peak}$ by the Bruce protocol was about 12% (male) or 13% (female) lower than $\dot{V}o_{2max}$, and a linear relationship was found between $\dot{V}o_{2peak}$ and $\dot{V}o_{2max}$. The peak values of % $\dot{V}o_{max}$ with the Bruce protocol were $89.2{\pm}3.3\;and\;87.5{\pm}3.6%$ and those with the inclined protocol $97.7{\pm}1.8\;and\;96.9{\pm}2.0%$ in the male and female groups, respectively. In the female group, $%\dot{V}o_{2max}$ at a given workload was higher than in the male group, while $\dot{V}o_{2}$ per kg body weight was the same. Maximum HR observed during the two exercises was $204{\pm}2\;and\;195{\pm}3\;beat\;min^{-1}$ in the male and female groups, respectively. Linear relationships were found, excluding the last points, between 1) $\dot{V}o_{2}$ and exercise time, 2) $\dot{V}o_{2}$ and $%\dot{V}o_{2max}\;and\;%HR_{max}$.

• Tuberculosis and Respiratory Diseases
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• 제39권6호
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• pp.511-516
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• 1992

연구배경 : 장기적 흡연이 폐암이나 만성폐쇄성폐질환등의 폐질환 및 여러 심장질환의 위험인자인 것은 잘 알려져 있으나 흡연이 단기적으로 운동시 호흡기 및 심혈관계 기능에 어떠한 영향을 미치는지에 대한 연구는 많지 않다. 흡연시에는 일산화탄소를 흡입하으로, 일산화탄소 흡입후 운동시에 나타나는 호흡수, 심박수, 호흡량 및 심장출량의 증가와 최대산소섭취량의 감소가 흡연후 운동시에도 관찰될 것으로 예상된다. 목적 : 흡연의 운동부하시 심폐기능에 대한 단기적 효과를 알아보고자 하였다. 방법 : 흡연자 13명을 대상으로 시간당 3개피를 5시간 흡연한 흡연일 및 흡연하지 않고 100% 산소를 15분간 흡입한 금연일을 무작위 순서로 정하여 두 번 단계적 운동부하 검사를 시행하였다. 결과 : 대상자 13명의 평균 연령은 $25{\pm}4.9$세, 평균 흡연력은 $6{\pm}5$ pack-years였고, 금연일과 흡연일간 일반 폐기능검사의 결과에는 차이가 없었다. 혈중 일산화 탄소혈색소량의 평균은 금연일 $1.45{\pm}0.83%$, 흡연일에 $5.97{\pm}1.34%$로서 흡연일에 유의하게 높았다(p<0.01). 무산소역치는 금연일 $1.53{\pm}0.20$ L/min, 흡연일에 $1.33{\pm}0.24$ L/min로서 흡연일에 유의하게 낮았으며(p<0.05) 최대산소섭취량은 금연일 $2.39{\pm}0.32$ L/min, 흡연일에 $2.09{\pm}0.32$ L/min로서 흡연일에 유의하게 낮았다(p<0.05). 안정시 심박수는 금연일에 분당 $75.46{\pm}5.83$회, 흡연일에 분당 $84.38{\pm}11.06$회로서 흡연일에 유의하게 높았으나(p<0.05) 최대심박수는 금연일에 $160.38{\pm}9.09$회, 흡연일에 $161.23{\pm}8.09$회로서 차이가 없었다. 결론 : 일반 폐기능검사는 양일간에 차이가 없었으나 금연일에 비해 흡연일에 무산소역치와 최대산소섭취량의 감소가 관찰되어 흡연은 단기적으로 운동부하시 심혈관계장애를 초래한다고 사료되었다.

• Safety and Health at Work
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• 제6권3호
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• pp.192-199
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• 2015

Background: Overweight, obesity, and cardiovascular disease risk factors are prevalent among firefighters in some developed countries. It is unclear whether physical activity and cardiopulmonary fitness reduce cardiovascular disease risk and the cardiovascular workload at work in firefighters. The present study investigated the relationship between leisure-time physical activity, cardiopulmonary fitness, cardiovascular disease risk factors, and cardiovascular workload at work in firefighters in Hong Kong. Methods: Male firefighters (n = 387) were randomly selected from serving firefighters in Hong Kong (n = 5,370) for the assessment of cardiovascular disease risk factors (obesity, hypertension, diabetes mellitus, dyslipidemia, smoking, known cardiovascular diseases). One-third (Target Group) were randomly selected for the assessment of off-duty leisure-time physical activity using the short version of the International Physical Activity Questionnaire. Maximal oxygen uptake was assessed, as well as cardiovascular workload using heart rate monitoring for each firefighter for four "normal" 24-hour working shifts and during real-situation simulated scenarios. Results: Overall, 33.9% of the firefighters had at least two cardiovascular disease risk factors. In the Target Group, firefighters who had higher leisure-time physical activity had a lower resting heart rate and a lower average working heart rate, and spent a smaller proportion of time working at a moderate-intensity cardiovascular workload. Firefighters who had moderate aerobic fitness and high leisure-time physical activity had a lower peak working heart rate during the mountain rescue scenario compared with firefighters who had low leisure-time physical activities. Conclusion: Leisure-time physical activity conferred significant benefits during job tasks of moderate cardiovascular workload in firefighters in Hong Kong.

• 미생물학회지
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• 제21권1호
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• pp.27-35
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• 1983

The stoichiometry between the consumption of CO and $O_2$ and the production of $CO_2(2CO+O_2{\rightarrow}2CO_2)$) showed that Pseudomonas carboxydohydrogena grows as a typical aerobic CO oxidizer with CO. The optimal concentration of CO for growth was found to be 30% in gas mixture with air. The initial buffer concentration of the culture medium did not affect the growth of this bacterium. P. carboxydohydrogena is an obligate aerobe and dose not use nitrate as a terminal electron acceptor. The CO dehydrogenase is an inducible and soluble enzyme. The reaction rate and stability were maximal at pH7.5, and the Arrhenius plot revealed an activation energy of 37.7kJ/mol (9.0 Kcal/mol). The crude enzyme used methylene blue, thionin, and toluylene blue as electron acceptors for the oxidation of CO to $Co_2$ under anaerobic conditions. It was found that water must be the source of the second oxygen atom for CO oxidation.

• 한국엔터테인먼트산업학회논문지
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• 제14권8호
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• pp.197-202
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• 2020

본 연구에서는 20대 여성의 카페인 중독이 심장호흡기계 능력에 미치는 영향을 조사하였다. 본 연구의 대상자는 G 광역시 소재의 H 대학교 여학생 35명을 카페인 중독자(n=17)과 카페인 비중독자(n=18)가 참여하였다. 심장능력을 평가하기 위해 사이클 에르고미터를 사용하여 최대산소섭취량, 최대에너지소비량, METs를 측정하였으며, 호흡기계 능력은 파워브리드 K5를 사용하여 최대들숨압, 평균들숨압, 최대들숨유속, 평균들숨유속, 최대들숨량, 평균들숨량을 측정하였다. 본 연구의 결과는 심장능력에서 카페인 중독군은 카페인 비중독군에 비해 최대산소섭취량과 METs에서 통계학적으로 유의한 감소를 보였으며, 호흡기계 능력에서는 카페인 중독군이 비중독군에 비해 최대들숨압, 평균들숨압, 최대들숨유속, 평균들숨유속에서 통계학적으로 유의한 감소를 보였다. 본 연구의 결과를 종합하면, 카페인 중독은 20대 여성의 심장호흡기계 능력의 감소를 보였다. 따라서 본 연구의 결과는 20대 여성의 카페인 중독예방을 위한 기초자료로 활용할 수 있을 것이다.

• Journal of Yeungnam Medical Science
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• 제36권3호
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• pp.219-224
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• 2019

Background: Korea has shown a rapid pace of aging and has become an aged society in a shorter period than Western countries. Therefore, it is important that middle-aged workers maintain their ability to work in the industrial field at the maximum level while maintaining their health. The purpose of this study was to analyze the factors affecting work ability and to use this data to maintain the working ability of middle-aged workers in the future. Methods: From 2015 to 2017, we surveyed 371 street cleaners who visited a health center for health promotion in a metropolitan city. The relationship between the general characteristics of the survey subjects and the Work Ability Index (WAI) was confirmed by a univariate analysis. Statistically significant (p<0.2) factors were selected and a multiple linear regression analysis was conducted with WAI scores as a dependent variable. Results: Age, body mass index, body fat percentage, the Alcohol Use Disorders Identification Test-Korea (AUDIT-K) scores, the Psychosocial Well-Being Index-Short Form (PWI-SF) scores, maximal oxygen consumption ($VO_{2max}$), and hypertension showed statistically significant correlations with the WAI in the univariate analysis. In the multivariate analysis, the $VO_{2max}$, AUDIT-K scores, and PWI-SF scores were included in the regression equation. $VO_{2max}$ had the greatest effect on the standardization coefficient indicating the relative contribution of independent variables, followed by the AUDIT-K scores and the PWI-SF scores. Conclusion: Programs to increase workers' physical work ability and alleviate psychosocial stress and drinking habits should be developed and implemented in the future.

• 생명과학회지
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• 제15권3호
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• pp.352-358
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• 2005

The purpose of this study was to examine the effect of various exercise intensity on Resting Metabolic Rate (RMR), excess post exercise energy expenditure (EPEE), and thyroid hormonal changes in trained (TR) and untrained (UT) people. The subject of the present study were divided into two groups and four periods: trained (TR; n=6) and untrained (UT; n=6) group. And the periods were divided as follows; Resting (R), Maximal (M), High intensity (H), and Low intensity (L). The percent body fat and RMR of all subjects were measured at every periods. The RMR was measured early in the morning following a 12-hour fast using MMX3B gas analyzer and blood sample were collected from the anticubital vein to investigate thyroid hormonal (T3, T4, Free T3, Free T4, & TSH) changes. All the RMR values were expressed as absolute value/BSA $(kcal/d/m^2)$. And We also analyzed mean energy expenditure for 30 minutes during and after different intensity exercise. There was significant difference in RMR among different intensity of exercise. in TR (p < .05) not in the UT group. however, there was no significant different percent body fat in TR and in UT group. In the energy expenditure, there was significant different between TR and UT in HEE (high intensity exercise energy expenditure), LEE (low intensity exercise energy expenditure), HEEPE (high intensity exercise energy expenditure post exercise) & LEEPE (low intensity exercise expenditure post exercise). In the hormonal level, there was significant different in T4 level in the TR group at H period and in T4, Free T3, & Free T4 levels in TR group at L period, however there was no significant different in the UT group. The present cross-sectional study was design to investigate the relationship between exercise intensity and RMR. The focus of this investigation was to compare RMR in aerobically trained (TR) and untrained (VI). The relationship among RMR, exercise intensity and percent body fat would best be investigated using MMX3B and body composition analyzer. Each subject completed measurement of percent body fat, RMR, hormone in the period of maximal oxygen uptake exercise (M), high intensity exercise (H), and low intensity exercise (L). From the results, Low intensity of exercise (L), there was a trend for an increased RMR (kcal/day) in the TR not for the UT. This is best explained not by the reduced percent body fat but by the highly induced energy expenditure (during exercise and post exercise energy expenditure) and increased T4, Free T3, and Free T4 hormonal levels in the low intensity exercise for the TR group.

• Tuberculosis and Respiratory Diseases
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• 제85권2호
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• pp.137-146
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• 2022

Background: Farinelli breathing (FB) exercise is a typical breathing exercise used by singers. This study aimed to compare effects of FB exercise and diaphragmatic breathing (DB) exercise on respiratory function and symptoms in patients with chronic obstructive pulmonary disease (COPD). Methods: Sixteen patients aged 51-80 years with mild or moderate COPD were recruited for this study. They were divided into two groups: DB group (n=8) and FB group (n=8). Both groups received complete breathing exercise training five times per week for 8 weeks. Their respiratory functions, COPD symptoms, cytokine levels, and oxidative stress variables were analyzed during pre- and post-tests. Dependent variables were compared between pre- and post-tests using paired t-tests. An independent t-test was used to compare variables between the groups. Differences were considered significant at p<0.05. Results: The maximal expiratory pressure (MEP), maximum oxygen consumption (VO₂max), and COPD Assessment Test (CAT) scores changed significantly in the DB group after the 8-week intervention compared to those at pre-test, whereas force vital capacity, forced expiratory volume in the first second, maximum voluntary ventilation, maximal inspiratory pressure (MIP), MEP, VO₂max, CAT score, tumor necrosis factor-α, and malondialdehyde level changed significantly in the FB group at post-test compared to those at pre-test. Moreover, both MIP and MEP in the FB group were significantly higher than those in the DB group. Conclusion: FB exercise improved respiratory functions and COPD symptoms of patients with COPD. It might be an alternative breathing exercise in pulmonary rehabilitation programs for patients with COPD.

• 대한의용생체공학회:의공학회지
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• 제32권4호
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• pp.319-327
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• 2011

Skeletal muscle fatigue is defined as a 'any reduction in the maximal capacity to generate force or power output', and is the reduction of oxygen consumption and by-product of metabolism. For the muscle fatigue therapy, low level laser has been introduced that leads the mitochondrial respiratory and attributes the muscle fatigue recovery. This study analyzed the muscle fatigue signals from electromyography(EMG) during low-level laser therapy (LLLT). Healthy subjects performed voluntary elbow flexion-extension excercise and received placebo LLLT and active LLLT using a 830 nm laser diode. Then, EMG were measured for the evaluation of muscle fatigue. The acquired EMG data were analyzed with median frequency and short time fourier transform methods. The results showed that the LLLT had a significant symptomatic relief of muscle fatigue based on the EMG frequency analysis. Therefore, the muscle fatigue analysis with EMG signals can be applied to quantitative evaluation for the monitoring of LLLT effects.

• 대한인간공학회:학술대회논문집
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• 대한인간공학회 1997년도 추계학술대회논문집
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• pp.152-159
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• 1997

인간공학을 적용하는데 있어 가장 기본적으로 다루어져야 할 것은 인간의 신체적, 심리적능력에 관한 연구이다. 특히 산업 현장에서 흔히 이루어지는 인간의 힘을 그 동력원으로 하는 수작업의 경우에 있어 서는 작업자가 직업적인 요인에 의해 피로가 누적되거나 신체적인 무리를 가져오지 않고 수행할 수 있는 안전한 작업기준의 설정이 필요하며 이를 위해서는 인간의 신체적 능격에관한 연구가 필수적이다. 특히 최근 들어 여성의 사회진출 기회가 다양해지고 있으며 많은 여성들이 육체적 노동을 필요로 하는 직업에 종사하고 있는 현실에서 한국여성들의 신체적 능력에 관한 자료가 절대적으로 부족한 상황이다. 따라서 본 연구에서는 현재 한국의 여성들이 활동하고 육체적 작업조건들이 적절하게 설정되어 있는지를 분석하기 위한 기초 자료로서 한국 여성들의 생리학적 작업능력(PWC:physiological work capacity)을 최대산소소모 능력(Maximal Oxygen Consumption: V0$_{2}$Max)의 관점에서 파악하고자 하였다. 또한 외국 여성의 생리 학적 작업능력과 한구 여성의 생리학적 작업능력을 비교 평가하여한국 여성에게 외국여성의 기준치를 적용 시키는 것이 적절한지를 분석해 보았다. 본 연구는 피실험자에게 위험부담을 주지 않는 Submaximal test의 연속적인 방법(continuous mathod)중 하나인 램프 테스트(Ramp test)를 사용하여 심박수(H.R)와 산소 소모 량(V0$_{2}$) 측정하여 최대심박수에서의 PWC를 추정하였다. 작업 부하는 자전거 에르고노미터와 트레드 밀을 사용하여부과하였다. 실험 결과로서 자전거 에르고미터의 경우 치대산소 소모량의 추정치 평균이 1818.79ml/min으로 나타 났고 트레드밀의 경우 2076.33ml/min으로 나타났다. 이 결과는 자전거 에르고 노미터의 결과는 자전거 에르고노미터의 결과가 트레드밀의 결과에 87.60%정도 나타났다.