Sweat is a hypotonic fluid excreted by sweat glands to cool the body. There are conflicting reports on whether or not body composition has an effect on thermoregulatory responses especially during exercise. This study...Sweat is a hypotonic fluid excreted by sweat glands to cool the body. There are conflicting reports on whether or not body composition has an effect on thermoregulatory responses especially during exercise. This study was aimed at determining and comparing sweat rate and electrolyte composition in underweight (BMI BMI 30 kg/m<sup>2</sup>) during moderate exercise. Forty women (19 - 25 years) were used during this study after assessing their health status. They were stratified for BMI with each group having a total of ten women. It was ensured that all the women used in the study were euhydrated before commencing the research. Before sweat collection, the treadmill was calibrated according to the Bruce Treadmill Protocol. Sweat samples were obtained with a sweat suction apparatus from a 120 cm<sup>2</sup> circular area marked on the skin of the face and neck, after a 15 minute fast walk on a treadmill at an inclination of 15° and at a speed of 4.2 km/h at 27°C room temperature. The time at which sweating commenced in the subjects was recorded. Sweat rate (L/hour) was calculated using the formula: sweat rate (L/hr) = (pre-exercise body weight - Post-exercise body weight)/exercise duration. Each sweat sample was collected and analysed immediately. The results showed that obese women had a significantly (P < 0.05) higher sweat rate and underweight women had a significantly (P < 0.05) lower sweat rate than all the other groups. Furthermore, subjects with a high body surface area showed significantly higher sweat rates compared to subjects with lower body surface area. Sweat electrolyte composition did not change in all BMI groups. In conclusion, obese subjects are more likely to develop fluid imbalances than underweight and normal weight subjects during moderate exercise. Also, underweight women might be at a thermoregulatory disadvantage because of their reduced body fat and body surface area.展开更多
该研究将24名拳击运动员按照是否穿着暴汗服分为实验组(n=12)和对照组(n=12),进行4周赛前训练,通过最大摄氧量和心率变异性指标来反映穿着暴汗服进行赛前减重对拳击运动员机能状态影响的差异。组内最大摄氧量指标前后比较,实验组提升3.0...该研究将24名拳击运动员按照是否穿着暴汗服分为实验组(n=12)和对照组(n=12),进行4周赛前训练,通过最大摄氧量和心率变异性指标来反映穿着暴汗服进行赛前减重对拳击运动员机能状态影响的差异。组内最大摄氧量指标前后比较,实验组提升3.04mL/(kg·min)(P<0.01),对照组提升1.16mL/(kg·min)(P<0.01);前、后比较均存在显著性差异。组间最大摄氧量指标提升百分比横向比较结果为:实验组与对照组之间存在显著性差异(P<0.05)。组内心率变异性指标前后纵向比较结果为:实验组的频域指标——相邻R-R间期差值均方根(Root Mean Square of SDs Between Adjacent NN Intervals,RMSSD)、相邻间期的差值标准差(Adjacent Normal RR Interval of the Difference Between the Standard Deviation,SDSD),以及总功率(Total Power,TP)、高频功率(High Frequency,HF)指标存在显著性差异(P<0.05);对照组的时域指标——R-R间期标准差(Standard Deviation of the NN Interval,SDNN)、RMSSD、SDSD,以及TP、低频功率(Low Frequency,LF)指标前后存在显著性差异(P<0.05)。组间心率变异性指标提升百分比横向比较结果为不存在显著性差异。得出结论:穿着暴汗服在赛前减重的同时有利于最大摄氧量的提高,且提升效果高于不穿暴汗服;穿着暴汗服进行赛前训练有利于提高拳击运动员的心率变异性。但是,穿和不穿暴汗服对心率变异性的提升效果并无显著差别。展开更多
Laboratory-scale experiments were carried out to evaluate the influences of operational parameters on the melt crystallization efficiency for p-cresol purification.The optimal crystallization conditions were determine...Laboratory-scale experiments were carried out to evaluate the influences of operational parameters on the melt crystallization efficiency for p-cresol purification.The optimal crystallization conditions were determined:dynamic pulsed aeration at 90 L·h-1 and the cooling rate of 0.6-0.8 ℃·min-1,followed by sweating at 0.2-0.3 ℃·min-1 for 40 min.Results also demonstrate that the melt crystallization efficiency is sensitive to feed concentration,which highlights this technology for separation and purification of high purity products.展开更多
The objective of this study was to determine how traditional Japanese style bathing could promote good health. Using healthy volunteers, we assessed body temperature (core and cutaneous), red blood cells, white blood ...The objective of this study was to determine how traditional Japanese style bathing could promote good health. Using healthy volunteers, we assessed body temperature (core and cutaneous), red blood cells, white blood cells (WBCs), venous blood gas parameters (PO2, SO2, PCO2, TCO2, HCO3, and pH), weight loss (which may indicate sweat volume), and the time until sweating before and after bathing. We simultaneously conducted a double-blind clinical trial using a bath additive group and a control group to investigate the effect of a bath additive on the same parameters. We found that bathing increased the core and cutaneous body temperature, as well as PO2, SO2, and blood pH. All of the subjects also showed increases in heart rate and weight loss (sweat volume). After bathing, the number and ratio of granulocytes increased while the number and ratio of lymphocytes decreased. These results tended to be emphasized in the bath additive group;however, significant between-group differences were not detected. Our results indicated that bathing improved blood circulation and had a modulatory effect on the autonomic nervous system. This suggested that traditional Japanese style bathing might contribute to good health and longevity;however, additional larger-scale studies were needed to confirm or refute this conclusion.展开更多
文摘Sweat is a hypotonic fluid excreted by sweat glands to cool the body. There are conflicting reports on whether or not body composition has an effect on thermoregulatory responses especially during exercise. This study was aimed at determining and comparing sweat rate and electrolyte composition in underweight (BMI BMI 30 kg/m<sup>2</sup>) during moderate exercise. Forty women (19 - 25 years) were used during this study after assessing their health status. They were stratified for BMI with each group having a total of ten women. It was ensured that all the women used in the study were euhydrated before commencing the research. Before sweat collection, the treadmill was calibrated according to the Bruce Treadmill Protocol. Sweat samples were obtained with a sweat suction apparatus from a 120 cm<sup>2</sup> circular area marked on the skin of the face and neck, after a 15 minute fast walk on a treadmill at an inclination of 15° and at a speed of 4.2 km/h at 27°C room temperature. The time at which sweating commenced in the subjects was recorded. Sweat rate (L/hour) was calculated using the formula: sweat rate (L/hr) = (pre-exercise body weight - Post-exercise body weight)/exercise duration. Each sweat sample was collected and analysed immediately. The results showed that obese women had a significantly (P < 0.05) higher sweat rate and underweight women had a significantly (P < 0.05) lower sweat rate than all the other groups. Furthermore, subjects with a high body surface area showed significantly higher sweat rates compared to subjects with lower body surface area. Sweat electrolyte composition did not change in all BMI groups. In conclusion, obese subjects are more likely to develop fluid imbalances than underweight and normal weight subjects during moderate exercise. Also, underweight women might be at a thermoregulatory disadvantage because of their reduced body fat and body surface area.
文摘该研究将24名拳击运动员按照是否穿着暴汗服分为实验组(n=12)和对照组(n=12),进行4周赛前训练,通过最大摄氧量和心率变异性指标来反映穿着暴汗服进行赛前减重对拳击运动员机能状态影响的差异。组内最大摄氧量指标前后比较,实验组提升3.04mL/(kg·min)(P<0.01),对照组提升1.16mL/(kg·min)(P<0.01);前、后比较均存在显著性差异。组间最大摄氧量指标提升百分比横向比较结果为:实验组与对照组之间存在显著性差异(P<0.05)。组内心率变异性指标前后纵向比较结果为:实验组的频域指标——相邻R-R间期差值均方根(Root Mean Square of SDs Between Adjacent NN Intervals,RMSSD)、相邻间期的差值标准差(Adjacent Normal RR Interval of the Difference Between the Standard Deviation,SDSD),以及总功率(Total Power,TP)、高频功率(High Frequency,HF)指标存在显著性差异(P<0.05);对照组的时域指标——R-R间期标准差(Standard Deviation of the NN Interval,SDNN)、RMSSD、SDSD,以及TP、低频功率(Low Frequency,LF)指标前后存在显著性差异(P<0.05)。组间心率变异性指标提升百分比横向比较结果为不存在显著性差异。得出结论:穿着暴汗服在赛前减重的同时有利于最大摄氧量的提高,且提升效果高于不穿暴汗服;穿着暴汗服进行赛前训练有利于提高拳击运动员的心率变异性。但是,穿和不穿暴汗服对心率变异性的提升效果并无显著差别。
基金Supported by the National Basic Research Program of China (2009CB219905)Program for Changjiang Scholars and Innovative Research Team in University (IRT0936)Innovating Fund of Tianjin University
文摘Laboratory-scale experiments were carried out to evaluate the influences of operational parameters on the melt crystallization efficiency for p-cresol purification.The optimal crystallization conditions were determined:dynamic pulsed aeration at 90 L·h-1 and the cooling rate of 0.6-0.8 ℃·min-1,followed by sweating at 0.2-0.3 ℃·min-1 for 40 min.Results also demonstrate that the melt crystallization efficiency is sensitive to feed concentration,which highlights this technology for separation and purification of high purity products.
文摘The objective of this study was to determine how traditional Japanese style bathing could promote good health. Using healthy volunteers, we assessed body temperature (core and cutaneous), red blood cells, white blood cells (WBCs), venous blood gas parameters (PO2, SO2, PCO2, TCO2, HCO3, and pH), weight loss (which may indicate sweat volume), and the time until sweating before and after bathing. We simultaneously conducted a double-blind clinical trial using a bath additive group and a control group to investigate the effect of a bath additive on the same parameters. We found that bathing increased the core and cutaneous body temperature, as well as PO2, SO2, and blood pH. All of the subjects also showed increases in heart rate and weight loss (sweat volume). After bathing, the number and ratio of granulocytes increased while the number and ratio of lymphocytes decreased. These results tended to be emphasized in the bath additive group;however, significant between-group differences were not detected. Our results indicated that bathing improved blood circulation and had a modulatory effect on the autonomic nervous system. This suggested that traditional Japanese style bathing might contribute to good health and longevity;however, additional larger-scale studies were needed to confirm or refute this conclusion.
