Oxygen uptake plays a crucial role in the evaluation of endurance performance during exercise and is extensively utilized for metabolic assessment. This study records the oxygen uptake during the exercise phase (i.e.,...Oxygen uptake plays a crucial role in the evaluation of endurance performance during exercise and is extensively utilized for metabolic assessment. This study records the oxygen uptake during the exercise phase (i.e., ascending or descending) of the stair exercise, utilizing an experimental dataset that includes ten participants and covers various exercise periods. Based on the designed experiment protocol, a non-parametric modeling method with kernel-based regularization is generally applied to estimate the oxygen uptake changes during the switching stairs exercise, which closely resembles daily life activities. The modeling results indicate the effectiveness of the non-parametric modeling approach when compared to fixed-order models in terms of accuracy, stability, and compatibility. The influence of exercise duration on estimated fitness reveals that the model of the phase-oxygen uptake system is not time-invariant related to respiratory metabolism regulation and muscle fatigue. Consequently, it allows us to study the humans’ conversion mechanism at different metabolic rates and facilitates the standardization and development of exercise prescriptions.展开更多
The interaction of pulsed electromagnetic fields (PEMF) with the human body may result in a variety of positive outcomes including analgesia, enhanced healing, chondroprotection, cognitive improvement and better quali...The interaction of pulsed electromagnetic fields (PEMF) with the human body may result in a variety of positive outcomes including analgesia, enhanced healing, chondroprotection, cognitive improvement and better quality of life. Previous human studies have also revealed the potential of PEMF to enhance muscle function and athletic performance. To further evaluate this potential, an open label pilot study was conducted with 19 competitive cyclists who repeatedly participated in 63 training routes. Cyclist performance was tracked before and during use of a novel and portable PEMF device that is worn as a wristband. Comparison of performance before and during use of the wristband revealed a significant association with improved muscle power. The odds ratio was 3.02 (P < 0.01) for experiencing increased muscle power while wearing the PEMF device. Among the cycling routes in which an increase was observed, the average increase in power was about 9.8%. The data suggests the novel PEMF technology may be a safe and effective therapeutic approach for improved physical performance and likely involves improved oxygen delivery due to reduced rouleaux (erythrocyte aggregation). These results warrant further investigation comprising larger studies and additional outcomes.展开更多
The microbial immobilization method using polyvinyl alcohol (PVA) gel as an immobilizing material was improved and used for entrapment of activated sludge. The oxygen uptake rate (OUR) was used to characterize the...The microbial immobilization method using polyvinyl alcohol (PVA) gel as an immobilizing material was improved and used for entrapment of activated sludge. The oxygen uptake rate (OUR) was used to characterize the biological activity of immobilized activated sludge. Three kinds of PVA-immobilized particles of activated sludge, that is, PVA-boric acid beads, PVA-sodium nitrate beads and PVA-orthophosphate beads were prepared, and their biological activity was compared by measuring the OUR value. The bioactivity of both autotrophic and heterotrophic microorganisms of activated sludge was determined using different synthetic wastewater media (containing 250 mg/L COD and 25 mg/L NH4^+ -N). The experimental results showed that the bioactivity and stability of the three kinds of immobilized activated sludge was greatly improved after activation. With respect of the bioactivity and the mechanical stability, the PVA-orthophosphate method may be a promising and economical technique for microbial immobilization.展开更多
Water soluble organic carbon (WSOC) is considered the most mobile and reactive soil carbon source and its characterization is an important issue for soil ecology study. A biodegradability test was set up to study WS...Water soluble organic carbon (WSOC) is considered the most mobile and reactive soil carbon source and its characterization is an important issue for soil ecology study. A biodegradability test was set up to study WSOC extracted from 7 soils differently managed. WSOC was extracted from soil with water (soil/water ratio of 1:2, W/V) for 30 min, and then tested for biodegradability by a liquid state respirometric test. Result obtained confirmed the finding that WSOC biodegradability depended on the both land use and management practice. These results suggested the biodegradability test as suitable method to characterize WSOC, and provided useful information to soil fertility.展开更多
Purpose: The aim of this study was to determine if heart rate variability(HRV) during incremental test could be used to estimate ventilatory threshold(VT) in professional basketball players, with sufficient precision ...Purpose: The aim of this study was to determine if heart rate variability(HRV) during incremental test could be used to estimate ventilatory threshold(VT) in professional basketball players, with sufficient precision to be used in their training. Furthermore, the second aim was to analyse the association between HRV and 3 methods of VT determination by gas analysis.Methods: Twenty-four professional basketball players(age: 23.4 ± 4.9 years; height: 195.4 ± 9.8 cm; body mass: 92.2 ± 11.9 kg) performed an incremental running test to exhaustion. First ventilatory threshold(VT1) was determined by ventilatory equivalent(VE) and HRV and second ventilatory threshold(VT2) was determined by 3 methods of gases analysis(V-slope, VE and gas exchange ratio(R), and HRV). Pearson's coefficient(r) was used to detect differences between data and the strength of each relationship. The mean of absolute differences and Bland–Altman analysis were used to evaluate whether there was agreement.Results: The results showed no significant differences in HR and oxygen consumption(VO2) at VT1 between the 2 methods. Furthermore, no significant differences among the methods of gases analysis and HRV were observed in speed, HR, and VO2 at VT2. Moreover, VTs estimated using HRV and gas methods were significantly correlated. Correlation in HR values was higher between R and HRV(r = 0.96) and VE and HRV(r = 0.96) than V-slope and HRV(r = 0.90).Conclusion: These findings provide a practical, inexpensive approach for evaluating specific training loads when determining VT2 in basketball players. Therefore, HRV is an alternative method to determine VT2 without the application of expensive technology that limits its use to laboratories.展开更多
Research on design of bicycles is concentrated on mechanism and auto appearance design, however few on matches between the bike and the rider. Since unreasonable human-bike relationship leads to both riders' worn-out...Research on design of bicycles is concentrated on mechanism and auto appearance design, however few on matches between the bike and the rider. Since unreasonable human-bike relationship leads to both riders' worn-out joints and muscle injuries, the design of bicycles should focus on the matching. In order to find the best position of human-bike system, simulation experiments on riding comfort under different riding postures are done with the lifemode software employed to facilitate the cycling process as well as to obtain the best position and the size function of it. With BP neural network and GA, analyzing simulation data, conducting regression analysis of parameters on different heights and bike frames, the equation of best position of human-bike system is gained at last. In addition, after selecting testers, customized bikes based on testers' height dimensions are produced according to the size function. By analyzing and comparing the experimental data that are collected from testers when riding common bicycles and customized bicycles, it is concluded that customized bicycles are four times even six times as comfortable as common ones. The equation of best position of human-bike system is applied to improve bikes' function, and the new direction on future design of bicycle frame parameters is presented.展开更多
Introduction and Objective: We investigated the association of endo-, meso- and ecto-morphic components of somatotype with aerobic power, mid-trunk flexibility and grip strength. Methods: Healthy male (n = 226) and fe...Introduction and Objective: We investigated the association of endo-, meso- and ecto-morphic components of somatotype with aerobic power, mid-trunk flexibility and grip strength. Methods: Healthy male (n = 226) and female (n = 86) subjects, aged 9 - 55 years, sedentary (n = 154) or participating in sports (n = 158) were studied. Anthro-pometrics (height, weight, 8 skin folds, arm and calf circumferences, elbow and knee diameters), maximal exercise O2 uptake, mid trunk flexibility, right and left grip strength were measured. Results: Sedentary adult females were endomorphic with mesomorph tendency, and had low aerobic power (27.8 ± 0.6 ml/Kg·min) and low (48.7 ± 1 Kg) grip strength. Sedentary males (young and adults) and Sports adult males were mesomorph with endomorphic tendency. Sports junior males were balanced mesomorph. Aerobic power was 54.1 ± 0.9 ml/Kg·min in sports young males, 53.8 ± 0.9 ml/Kg·min in sports adult males, 41.2 ± 4.3 ml/Kg·min in sedentary young males, and 39.5 ± 1 ml/Kg·min in sedentary adult males. Grip strength was 89.9 ± 1.7 Kg in sports adult males, 86.7 ± 2 Kg in sedentary adult males, 75.6 ± 2.2 Kg in sports junior males and 52 ± 9.1 Kg in young sedentary males. Step-wise multiple regression analysis of somatotype components on aerobic power revealed dominant negative contribution (P < 0.001) of endomorphy (r<sup>2</sup> = 0.57, 57%), and small but significant positive contributions of mesomorphy (0.6%) and ectomorphy (0.6%): Aerobic power = [56.1 - 4.3 (endomorphy) + (mesomorphy) + 1.4 (ectomorphy)] ± 9.1 SEE. Height and somatotype components accounted for 69% of the variance (R2) in grip strength;height had greatest contribution (60%): Grip Strength = [1.7 (Height) - 6.5 (ectomorphy) - 3.4 (endomorphy) - 2 (mesomorphy) - 200] ± 12.9 SEE. Measured variables accounted for <2% of flexibility variance. Conclusion: Endomorphy contributes greatly and negatively to variance in aerobic power. Body height was the anthropometric variable with the greatest positive association with the variance in grip strength. Flexibility appears to be unrelated to somatotype components.展开更多
Idiopathic pulmonary fibrosis (IPF) is a chronic, life-limiting with an average life expectancy of 05 years following the onset of the disease, with no curative treatments. These patients need palliative care and reha...Idiopathic pulmonary fibrosis (IPF) is a chronic, life-limiting with an average life expectancy of 05 years following the onset of the disease, with no curative treatments. These patients need palliative care and rehabilitation is one of the methods that can be used to improve quality of life (QoL) among these patients. Yet the research conducted to assess benefits of pulmonary rehabilitation (PR) in terms of improving physical activity and QoL in IPF patients remains limited. Hence this study aims to evaluate the effect of a bespoke pulmonary rehabilitation programme, on the physical, physiological and psychological parameters and improvements of QoL among IPF patients. Eleven (11) subjects with IPF received 6 weeks of pulmonary rehabilitation. An interviewer administered quality of life questionnaire, six-minute walking test (6MWT), Incremental bicycle exercise tests were performed, and cardiac and respiratory parameters were assessed pre- and post-rehabilitation. The 6MWT was significantly increased following training (Pre 312.55<span "=""> </span>±<span "=""> </span>89.99;Post, 380.73 ±<span "=""> </span>59.60). A significant improvement was observed in overall QoL (2.226 ± 0.026), dyspnoea (<span style="color:#4F4F4F;">-</span>0.455<span "=""> </span>±<span "=""> </span>0.004) anxiety (<span "=""><span style="color:#4F4F4F;">-</span>2.070</span><span "=""> </span>±<span "=""> </span>0.038), depression (<span "=""><span style="color:#4F4F4F;">-</span>2.217</span><span "=""> </span>±<span "=""> </span><span "="">0.027) scores. No significant changes were found in the VO<sub>2</sub> max and other cardiopulmonary parameters, while non-significant improvement was seen in SpO<sub>2</sub> at peak exercise from 85.8 </span>- 86.5. Bespoke pulmonary rehabilitation program is beneficial in short term improvement of the functional exercise capacity, dyspnoea and QoL among IPF patients.展开更多
Objectives To analyze the six-minute walk test (6MWT) and gas exchange of 5 heart transplantation patients and to approach the variation tendency of exercise tolerance, oxygen uptake ( VO2 ) and heart rate chronot...Objectives To analyze the six-minute walk test (6MWT) and gas exchange of 5 heart transplantation patients and to approach the variation tendency of exercise tolerance, oxygen uptake ( VO2 ) and heart rate chronotropic response. Methods 5 cases of heart transplantation patients ( age 25 - 52 years) were undertaken 6MWT 6 - 30 months after operation, synchronizing gas exchanging parameters were measured by wireless portable remote sensing K4B^2 gas analyzer, 51 normal controls were compared. Results The six-minute walk distance (6MWD) of 5 patients were (592.6 ± 26.7 ) m (558 - 625 ) m, the ascending tendency during exercise was slower, the maximum heart rates were 80% ± 6% of age-predicting maximal heart rate, lower than normal control (86%) ; the end point VO2/kg were (21.8 ± 1.4 ) mL/min · kg ( 19. 94 - 23.60) mL/min · kg. Conclusions The 6WMD and VO2 of 5 patients reached normal range, but the heart rate chronotropic response and VO2 ascending tendency were slower than those of normal controls.展开更多
Rationale: Patients with cancer commonly experience dyspnea originating from ventilatory, circulatory and musculoskeletal sources, and dyspnea is best determined by cardiopulmonary exercise testing (CPET). Objectives:...Rationale: Patients with cancer commonly experience dyspnea originating from ventilatory, circulatory and musculoskeletal sources, and dyspnea is best determined by cardiopulmonary exercise testing (CPET). Objectives: In this retrospective pilot study, we evaluated patients with hematologic and solid malignancies by CPET to determine the primary source of their dyspnea. Methods: Subjects were exercised on a cycle ergometer with increasing workloads. Minute ventilation, heart rate, breathing reserve, oxygen uptake (V’O<sub>2</sub>), O<sub>2</sub>-pulse, ventilatory equivalents for carbon dioxide and oxygen (V’<sub>E</sub>/V’CO<sub>2</sub> and V’<sub>E</sub>/V’O<sub>2</sub>, respectively) were measured at baseline and peak exercise. The slope and intercept for V’<sub>E</sub>/V’CO<sub>2</sub> was computed for all subjects. Peak V’O<sub>2</sub> 4% predicted indicated a circulatory or ventilatory limitation. Results: Complete clinical and physiological data were available for 36 patients (M/F 20/16);32 (89%) exhibited ventilatory or circulatory limitation as shown by a reduced peak V’O<sub>2</sub> and 10 subjects with normal physiologic data. The largest cohort comprised the pulmonary vascular group (n = 18) whose mean ± SD peak V’O<sub>2</sub> was 61% ± 17% predicted. There were close associations between V’O<sub>2</sub> and spirometric values. Peak V’<sub>E</sub>/V’O<sub>2</sub> and V’<sub>E</sub>/V’CO<sub>2</sub> were highest in the circulatory and ventilatory cohorts, consistent with increase in dead space breathing. The intercept of the V’<sub>E</sub>-V’CO<sub>2</sub> relationship was lowest in patients with cardiovascular impairment. Conclusion: Dyspneic patients with malignancies exhibit dead space breathing, many exhibiting a circulatory source for exercise limitation with a prominent pulmonary vascular component. Potential factors include effects of chemo- and radiation therapy on cardiac function and pulmonary vascular endothelium.展开更多
In wastewater treatment plants(WWTPs)using the activated sludge process,two methods are widely used to improve aeration efficiency — use of high-efficiency aeration devices and optimizing the aeration control strat...In wastewater treatment plants(WWTPs)using the activated sludge process,two methods are widely used to improve aeration efficiency — use of high-efficiency aeration devices and optimizing the aeration control strategy. Aeration efficiency is closely linked to sludge characteristics(such as concentrations of mixed liquor suspended solids(MLSS)and microbial communities)and operating conditions(such as air flow rate and operational dissolved oxygen(DO)concentrations). Moreover,operational DO is closely linked to effluent quality. This study,which is in reference to WWTP discharge class A Chinese standard effluent criteria,determined the growth kinetics parameters of nitrifiers at different DO levels in small-scale tests. Results showed that the activated sludge system could meet effluent criteria when DO was as low as 0.3 mg/L,and that nitrifier communities cultivated under low DO conditions had higher oxygen affinity than those cultivated under high DO conditions,as indicated by the oxygen half-saturation constant and nitrification ability. Based on nitrifier growth kinetics and on the oxygen mass transfer dynamic model(determined using different air flow rate(Q′air)and mixed liquor volatile suspended solids(MLVSS)values),theoretical analysis indicated limited potential for energy saving by improving aeration diffuser performance when the activated sludge system had low oxygen consumption; however,operating at low DO and low MLVSS could significantly reduce energy consumption. Finally,a control strategy coupling sludge retention time and MLVSS to minimize the DO level was discussed,which is critical to appropriate setting of the oxygen point and to the operation of low DO treatment technology.展开更多
Objective:To determine whether the ingestion of a herbal supplement called Rhodiola-Gingko Capsule(RGC) would enhance the endurance performance of healthy volunteers and change relevant hormones in a favorable manner....Objective:To determine whether the ingestion of a herbal supplement called Rhodiola-Gingko Capsule(RGC) would enhance the endurance performance of healthy volunteers and change relevant hormones in a favorable manner.Methods:Seventy healthy male volunteers(age ranges from 18 to 22 years old) were randomly assigned to RGC group(35 cases,each capsule containing 270 mg herbal extracts,4 capsules per day) or placebo group(35 cases,equivalent placebo preparation) for 7 weeks using computerproduced digital random...展开更多
Beijing will host the 2022 Winter Olympics,and China strengthens research on various aspects to allow their athletes to compete successfully in winter sport.Simultaneously,Government-directed initiatives aim to increa...Beijing will host the 2022 Winter Olympics,and China strengthens research on various aspects to allow their athletes to compete successfully in winter sport.Simultaneously,Government-directed initiatives aim to increase public participation in recreational winter sport.These parallel developments allow research to advance knowledge and understanding of the physiological determinants of performance and health related to winter sport.Winter sport athletes often conduct a substan-tial amount of training with high volumes of low-to-moderate exercise intensity and lower volumes of high-intensity work.Moreover,much of the training occur at low ambient temperatures and winter sport athletes have high risk of developing asthma or asthma-related conditions,such as exercise-induced bronchoconstriction.The high training volumes require optimal nutrition with increased energy and dietary protein requirement to stimulate muscle protein synthesis response in the post-exercise period.Whether higher protein intake is required in the cold should be investigated.Cross-country ski-ing is performed mostly in Northern hemisphere with a strong cultural heritage and sporting tradition.It is expected that innovative initiatives on recruitment and training during the next few years will target to enhance performance of Chinese athletes in classical endurance-based winter sport.The innovation potential coupled with resourcing and population may be substantial with the potential for China to become a significant winter sport nation.This paper discusses the physiological aspects of endurance training and performance in winter sport highlighting areas where innovation may advance in athletic performance in cold environments.In addition,to ensure sustainable development of snow sport,a quality ski patrol and rescue system is recommended for the safety of increasing mass participation.展开更多
Purpose To challenge current conventions in paediatric sport science and use data from recent longitudinal studies to elu-cidate the development of aerobic and anaerobic fitness,with reference to youth athletes.Method...Purpose To challenge current conventions in paediatric sport science and use data from recent longitudinal studies to elu-cidate the development of aerobic and anaerobic fitness,with reference to youth athletes.Methods(1)To critically review the traditional practice of ratio scaling physiological variables with body mass and,(2)to use multiplicative allometric models of longitudinal data,founded on 1053(550 from boys)determinations of 10-17-year-olds’peak oxygen uptake(VO2)and 763(405 from boys)determinations of 11-17-year-olds’peak power output(PP)and mean power output(MP),to investigate the development of aerobic and anaerobic fitness in youth.Results The statistical assumptions underpinning ratio scaling of physiological variables in youth are seldom met.Multiplicative allometric modelling of longitudinal data has demonstrated that fat free mass(FFM)acting as a surrogate for active muscle mass,is the most powerful morphological influence on PP,MP,and peak VO2.With FFM appropriately controlled for,age effects remain significant but additional,independent effects of maturity status on anaerobic and aerobic fitness are negated.Conclusions Ratio scaling of physiological variables with body mass is fallacious,confounds interpretation of the develop-ment of anaerobic and aerobic fitness,and misleads fitness comparisons within and across youth sports.Rigorous evalua-tion of the development of anaerobic and aerobic fitness in youth requires longitudinal analyses of sex-specific,concurrent changes in age-and maturation-driven morphological covariates.Age and maturation-driven changes in FFM are essential considerations when evaluating the physiological development of youth athletes.展开更多
Purpose The purpose was to investigate whether an increased amount of training while carrying the rifle affects skiing in well-trained biathletes at submaximal and maximal workloads during a pre-season period lasting ...Purpose The purpose was to investigate whether an increased amount of training while carrying the rifle affects skiing in well-trained biathletes at submaximal and maximal workloads during a pre-season period lasting a minimum of 12 weeks.Methods Seventeen well-trained biathletes(9 females,8 males)were assigned to an intervention(IG,n=10)or control(CG,n=7)group.Before(T1)and after(T2)the training intervention all participants performed,using treadmill roller-skiing,a submaximal test without the rifle on one day and two submaximal workloads and a maximal time trial(TT)with the rifle on a subsequent day.Between T1 and T2 all participants performed a minimum of 12 weeks of normal training,the only difference between groups being that IG performed more of their training sessions carrying the rifle.Results IG performed more training compared to CG(15.4±1.1 vs.11.2±2.6 h/week,P<0.05),including a higher amount of training with the rifle(3.1±0.6 vs.1.1±0.3 h/week,P<0.001).Speed at 4 mmol/L of blood lactate increased significantly for CG from T1 to T2(P=0.028),while only tended to increase for IG(P=0.058).Performance during the TT,VO2max and the aerobic metabolic rate increased significantly from T1 to T2,although the differences disappeared when including the speed at baseline as a covariate.Conclusion According to the present results,increasing training while carrying the rifle by 2 h/week does not appear to improve skiing performance in well-trained biathletes.In addition,physiological markers at submaximal and maximal intensities while carrying the rifle were not affected after the training intervention.展开更多
Increased cardiovascular fitness,VO_(2max),is associated with enhanced endurance capacity and a decreased rate of mortality.High intensity interval training(HIIT)is one of the best methods to increase VO_(2max)and end...Increased cardiovascular fitness,VO_(2max),is associated with enhanced endurance capacity and a decreased rate of mortality.High intensity interval training(HIIT)is one of the best methods to increase VO_(2max)and endurance capacity for top athletes and for the general public as well.Because of the high intensity of this type of training,the adaptive response is not restricted to Type I fibers,as found for moderate intensity exercise of long duration.Even with a short exercise duration,HIIT can induce activation of AMPK,PGC-1α,SIRT1 and ROS pathway as well as by the modulation of Ca^(2+)homeostasis,leading to enhanced mitochondrial biogenesis,and angiogenesis.The present review summarizes the current knowledge of the adaptive response of HIIT.展开更多
Respirogram technology has been widely applied for aerobic process, however, the response of respirogram to anoxic denitrification is still unclear. To reveal such response may help to design a new method for the eval...Respirogram technology has been widely applied for aerobic process, however, the response of respirogram to anoxic denitrification is still unclear. To reveal such response may help to design a new method for the evaluation of the performance of denitrification. The size distribution of flocs measured at different denitrification moments demonstrated a clear expansion of flocs triggered by denitrification, during which higher specific endogenous and quasi-endogenous respiration rates(SOUReand SOURq) were also observed. Furthermore,SOURqincreases exponentially with the specific denitrification rate(SDNR), suggesting that there should be a maximum SDNR in conventional activated sludge systems. Based on these findings, an index Rq/t, defined as the ratio of quasi-endogenous(OURq) to maximum respiration rate(OURt), is proposed to estimate the denitrification capacity that higher Rq/tindicates higher denitrification potential, which can be readily obtained without complex measurement or analysis, and it offers a novel and promising respirogram-based approach for denitrification estimation and control by taking measures to extend anoxic time to maintain its value at a high level within a certain range.展开更多
This work aims to explore a procedure to improve biological wastewater treatment efficiency using low inten-sity ultrasound.The aerobic activated sludge from a munici-pal wastewater treatment plant was used as the exp...This work aims to explore a procedure to improve biological wastewater treatment efficiency using low inten-sity ultrasound.The aerobic activated sludge from a munici-pal wastewater treatment plant was used as the experimental material.Oxygen uptake rate(OUR)of the activated sludge(AS)was determined to indicate the changes of AS activity stimulated by ultrasound at 35 kHz for 0-40 min with ultrasonic intensities of 0-1.2 W/cm^(2).The highest OUR was observed at the ultrasonic intensity of 0.3 W/cm^(2) and an irradiation period of 10 min;more than 15%increase was achieved immediately after sonication.More significantly,the AS activity stimulated by ultrasound could last 24 h after sonication,and the AS activity achieved its peak value within 8 h after sonication,or nearly 100%higher than the initial level after sonication.Therefore,to improve the wastewater treatment efficiency of bioreactors,ultrasound with an intensity of 0.3 W/cm^(2) could be employed to irradiate a part of the AS in the bioreactor for 10 min every 8 h.展开更多
In this study,an anaerobic/anoxic/oxic(A^(2)O)wastewater treatment process was implemented to treat domestic wastewater with short-term atrazine addition.The results provided an evaluation on the effects of an acciden...In this study,an anaerobic/anoxic/oxic(A^(2)O)wastewater treatment process was implemented to treat domestic wastewater with short-term atrazine addition.The results provided an evaluation on the effects of an accidental pollution on the operation of a wastewater treatment plant(WWTP)in relation to Chemical Oxygen Demand(COD)and biological nutrient removal.Domestic wastewater with atrazine addition in 3 continuous days was treated when steady biological nutrient removal was achieved in the A^(2)O process.The concentrations of atrazine were 15,10,and 5 mg%L–1 on days 1,2 and 3,respectively.The results showed that atrazine addition did not affect the removal of COD.The specific NH4þoxidation rate and NO3–reduction rate decreased slightly due to the short-term atrazine addition.However,it did not affect the nitrogen removal due to the high nitrification and denitrification capacity of the system.Total nitrogen(TN)removal was steady,and more than 70%was removed during the period studied.The phosphorus removal rate was not affected by the short-term addition of atrazine under the applied experimental conditions.However,more poly-hydroxy-alkanoate(PHA)was generated and utilized during atrazine addition.The results of the oxygen uptake rate(OUR)showed that the respiration of nitrifiers decreased significantly,while the activity of carbon utilizers had no obvious change with the atrazine addition.Atrazine was not removed with the A^(2)O process,even via absorption by the activated sludge in the process of the short-term addition of atrazine.展开更多
Objective The purpose of the present study was to investigate the association between cardiorespiratory fitness(CRF)measured as peak oxygen uptake(VO_(2peak),expressed in mL/min)and body mass index(BMI)in a large coho...Objective The purpose of the present study was to investigate the association between cardiorespiratory fitness(CRF)measured as peak oxygen uptake(VO_(2peak),expressed in mL/min)and body mass index(BMI)in a large cohort of apparently healthy subjects.Methods BMI and VO_(2peak)were measured in a cross-sectional study of 8470 apparently healthy adults.VO_(2peak)(mL/min)was determined by an incremental cycle ergometer test to exhaustion.Linear regression analyses were performed to identify predictors of CRF.Results There was no difference in CRF between adults with a normal weight(BMI between 18.5-24.9 kg/m^(2))and those who were overweight(BMI 25.0-29.9 kg/m^(2)).Subjects who were underweight(BMI<18.5 kg/m^(2))as well as females who were obese(BMI≥30.0 kg/m^(2))showed a reduced CRF compared to the normal and overweight groups.Age,height,and gender were significant predictors of CRF(R^(2)=0.467,P<0.0001);BMI did not add significantly to this relationship.Conclusion Our findings indicate that BMI was not associated with CRF in addition to age,height,and gender.In subjects with a BMI<18.5 kg/m^(2),CRF was lower compared to subjects with a BMI between 18.5 and 29.9 kg/m^(2).In obese subjects,CRF was only lower in females compared to females with a BMI between 18.5 and 29.9 kg/m^(2).Correcting CRF for BMI may be beneficial for subjects with a low BMI,and females with a BMI≥30.0 kg/m^(2).The outcome of this study might help to improve the interpretation of exercise testing results in individuals with a low or high BMI.展开更多
基金supported by the National Natural Science Foundation of China(No.62103449)the Start-up Research Fund of Southeast University(RF1028623007)the Zhishan Youth Scholar Support Program of Southeast University(2242023R40044).
文摘Oxygen uptake plays a crucial role in the evaluation of endurance performance during exercise and is extensively utilized for metabolic assessment. This study records the oxygen uptake during the exercise phase (i.e., ascending or descending) of the stair exercise, utilizing an experimental dataset that includes ten participants and covers various exercise periods. Based on the designed experiment protocol, a non-parametric modeling method with kernel-based regularization is generally applied to estimate the oxygen uptake changes during the switching stairs exercise, which closely resembles daily life activities. The modeling results indicate the effectiveness of the non-parametric modeling approach when compared to fixed-order models in terms of accuracy, stability, and compatibility. The influence of exercise duration on estimated fitness reveals that the model of the phase-oxygen uptake system is not time-invariant related to respiratory metabolism regulation and muscle fatigue. Consequently, it allows us to study the humans’ conversion mechanism at different metabolic rates and facilitates the standardization and development of exercise prescriptions.
文摘The interaction of pulsed electromagnetic fields (PEMF) with the human body may result in a variety of positive outcomes including analgesia, enhanced healing, chondroprotection, cognitive improvement and better quality of life. Previous human studies have also revealed the potential of PEMF to enhance muscle function and athletic performance. To further evaluate this potential, an open label pilot study was conducted with 19 competitive cyclists who repeatedly participated in 63 training routes. Cyclist performance was tracked before and during use of a novel and portable PEMF device that is worn as a wristband. Comparison of performance before and during use of the wristband revealed a significant association with improved muscle power. The odds ratio was 3.02 (P < 0.01) for experiencing increased muscle power while wearing the PEMF device. Among the cycling routes in which an increase was observed, the average increase in power was about 9.8%. The data suggests the novel PEMF technology may be a safe and effective therapeutic approach for improved physical performance and likely involves improved oxygen delivery due to reduced rouleaux (erythrocyte aggregation). These results warrant further investigation comprising larger studies and additional outcomes.
基金Project supported by the National Natural Science Foundation of China(No.50327802,50325824,50678089).
文摘The microbial immobilization method using polyvinyl alcohol (PVA) gel as an immobilizing material was improved and used for entrapment of activated sludge. The oxygen uptake rate (OUR) was used to characterize the biological activity of immobilized activated sludge. Three kinds of PVA-immobilized particles of activated sludge, that is, PVA-boric acid beads, PVA-sodium nitrate beads and PVA-orthophosphate beads were prepared, and their biological activity was compared by measuring the OUR value. The bioactivity of both autotrophic and heterotrophic microorganisms of activated sludge was determined using different synthetic wastewater media (containing 250 mg/L COD and 25 mg/L NH4^+ -N). The experimental results showed that the bioactivity and stability of the three kinds of immobilized activated sludge was greatly improved after activation. With respect of the bioactivity and the mechanical stability, the PVA-orthophosphate method may be a promising and economical technique for microbial immobilization.
文摘Water soluble organic carbon (WSOC) is considered the most mobile and reactive soil carbon source and its characterization is an important issue for soil ecology study. A biodegradability test was set up to study WSOC extracted from 7 soils differently managed. WSOC was extracted from soil with water (soil/water ratio of 1:2, W/V) for 30 min, and then tested for biodegradability by a liquid state respirometric test. Result obtained confirmed the finding that WSOC biodegradability depended on the both land use and management practice. These results suggested the biodegradability test as suitable method to characterize WSOC, and provided useful information to soil fertility.
文摘Purpose: The aim of this study was to determine if heart rate variability(HRV) during incremental test could be used to estimate ventilatory threshold(VT) in professional basketball players, with sufficient precision to be used in their training. Furthermore, the second aim was to analyse the association between HRV and 3 methods of VT determination by gas analysis.Methods: Twenty-four professional basketball players(age: 23.4 ± 4.9 years; height: 195.4 ± 9.8 cm; body mass: 92.2 ± 11.9 kg) performed an incremental running test to exhaustion. First ventilatory threshold(VT1) was determined by ventilatory equivalent(VE) and HRV and second ventilatory threshold(VT2) was determined by 3 methods of gases analysis(V-slope, VE and gas exchange ratio(R), and HRV). Pearson's coefficient(r) was used to detect differences between data and the strength of each relationship. The mean of absolute differences and Bland–Altman analysis were used to evaluate whether there was agreement.Results: The results showed no significant differences in HR and oxygen consumption(VO2) at VT1 between the 2 methods. Furthermore, no significant differences among the methods of gases analysis and HRV were observed in speed, HR, and VO2 at VT2. Moreover, VTs estimated using HRV and gas methods were significantly correlated. Correlation in HR values was higher between R and HRV(r = 0.96) and VE and HRV(r = 0.96) than V-slope and HRV(r = 0.90).Conclusion: These findings provide a practical, inexpensive approach for evaluating specific training loads when determining VT2 in basketball players. Therefore, HRV is an alternative method to determine VT2 without the application of expensive technology that limits its use to laboratories.
基金Supported by Special Found Project for Technology Innovation of Tianjin(Grant No.10FDZDGX00500)Tianjin Wu Qing Special Fund of Science and Technology,China
文摘Research on design of bicycles is concentrated on mechanism and auto appearance design, however few on matches between the bike and the rider. Since unreasonable human-bike relationship leads to both riders' worn-out joints and muscle injuries, the design of bicycles should focus on the matching. In order to find the best position of human-bike system, simulation experiments on riding comfort under different riding postures are done with the lifemode software employed to facilitate the cycling process as well as to obtain the best position and the size function of it. With BP neural network and GA, analyzing simulation data, conducting regression analysis of parameters on different heights and bike frames, the equation of best position of human-bike system is gained at last. In addition, after selecting testers, customized bikes based on testers' height dimensions are produced according to the size function. By analyzing and comparing the experimental data that are collected from testers when riding common bicycles and customized bicycles, it is concluded that customized bicycles are four times even six times as comfortable as common ones. The equation of best position of human-bike system is applied to improve bikes' function, and the new direction on future design of bicycle frame parameters is presented.
文摘Introduction and Objective: We investigated the association of endo-, meso- and ecto-morphic components of somatotype with aerobic power, mid-trunk flexibility and grip strength. Methods: Healthy male (n = 226) and female (n = 86) subjects, aged 9 - 55 years, sedentary (n = 154) or participating in sports (n = 158) were studied. Anthro-pometrics (height, weight, 8 skin folds, arm and calf circumferences, elbow and knee diameters), maximal exercise O2 uptake, mid trunk flexibility, right and left grip strength were measured. Results: Sedentary adult females were endomorphic with mesomorph tendency, and had low aerobic power (27.8 ± 0.6 ml/Kg·min) and low (48.7 ± 1 Kg) grip strength. Sedentary males (young and adults) and Sports adult males were mesomorph with endomorphic tendency. Sports junior males were balanced mesomorph. Aerobic power was 54.1 ± 0.9 ml/Kg·min in sports young males, 53.8 ± 0.9 ml/Kg·min in sports adult males, 41.2 ± 4.3 ml/Kg·min in sedentary young males, and 39.5 ± 1 ml/Kg·min in sedentary adult males. Grip strength was 89.9 ± 1.7 Kg in sports adult males, 86.7 ± 2 Kg in sedentary adult males, 75.6 ± 2.2 Kg in sports junior males and 52 ± 9.1 Kg in young sedentary males. Step-wise multiple regression analysis of somatotype components on aerobic power revealed dominant negative contribution (P < 0.001) of endomorphy (r<sup>2</sup> = 0.57, 57%), and small but significant positive contributions of mesomorphy (0.6%) and ectomorphy (0.6%): Aerobic power = [56.1 - 4.3 (endomorphy) + (mesomorphy) + 1.4 (ectomorphy)] ± 9.1 SEE. Height and somatotype components accounted for 69% of the variance (R2) in grip strength;height had greatest contribution (60%): Grip Strength = [1.7 (Height) - 6.5 (ectomorphy) - 3.4 (endomorphy) - 2 (mesomorphy) - 200] ± 12.9 SEE. Measured variables accounted for <2% of flexibility variance. Conclusion: Endomorphy contributes greatly and negatively to variance in aerobic power. Body height was the anthropometric variable with the greatest positive association with the variance in grip strength. Flexibility appears to be unrelated to somatotype components.
文摘Idiopathic pulmonary fibrosis (IPF) is a chronic, life-limiting with an average life expectancy of 05 years following the onset of the disease, with no curative treatments. These patients need palliative care and rehabilitation is one of the methods that can be used to improve quality of life (QoL) among these patients. Yet the research conducted to assess benefits of pulmonary rehabilitation (PR) in terms of improving physical activity and QoL in IPF patients remains limited. Hence this study aims to evaluate the effect of a bespoke pulmonary rehabilitation programme, on the physical, physiological and psychological parameters and improvements of QoL among IPF patients. Eleven (11) subjects with IPF received 6 weeks of pulmonary rehabilitation. An interviewer administered quality of life questionnaire, six-minute walking test (6MWT), Incremental bicycle exercise tests were performed, and cardiac and respiratory parameters were assessed pre- and post-rehabilitation. The 6MWT was significantly increased following training (Pre 312.55<span "=""> </span>±<span "=""> </span>89.99;Post, 380.73 ±<span "=""> </span>59.60). A significant improvement was observed in overall QoL (2.226 ± 0.026), dyspnoea (<span style="color:#4F4F4F;">-</span>0.455<span "=""> </span>±<span "=""> </span>0.004) anxiety (<span "=""><span style="color:#4F4F4F;">-</span>2.070</span><span "=""> </span>±<span "=""> </span>0.038), depression (<span "=""><span style="color:#4F4F4F;">-</span>2.217</span><span "=""> </span>±<span "=""> </span><span "="">0.027) scores. No significant changes were found in the VO<sub>2</sub> max and other cardiopulmonary parameters, while non-significant improvement was seen in SpO<sub>2</sub> at peak exercise from 85.8 </span>- 86.5. Bespoke pulmonary rehabilitation program is beneficial in short term improvement of the functional exercise capacity, dyspnoea and QoL among IPF patients.
文摘Objectives To analyze the six-minute walk test (6MWT) and gas exchange of 5 heart transplantation patients and to approach the variation tendency of exercise tolerance, oxygen uptake ( VO2 ) and heart rate chronotropic response. Methods 5 cases of heart transplantation patients ( age 25 - 52 years) were undertaken 6MWT 6 - 30 months after operation, synchronizing gas exchanging parameters were measured by wireless portable remote sensing K4B^2 gas analyzer, 51 normal controls were compared. Results The six-minute walk distance (6MWD) of 5 patients were (592.6 ± 26.7 ) m (558 - 625 ) m, the ascending tendency during exercise was slower, the maximum heart rates were 80% ± 6% of age-predicting maximal heart rate, lower than normal control (86%) ; the end point VO2/kg were (21.8 ± 1.4 ) mL/min · kg ( 19. 94 - 23.60) mL/min · kg. Conclusions The 6WMD and VO2 of 5 patients reached normal range, but the heart rate chronotropic response and VO2 ascending tendency were slower than those of normal controls.
文摘Rationale: Patients with cancer commonly experience dyspnea originating from ventilatory, circulatory and musculoskeletal sources, and dyspnea is best determined by cardiopulmonary exercise testing (CPET). Objectives: In this retrospective pilot study, we evaluated patients with hematologic and solid malignancies by CPET to determine the primary source of their dyspnea. Methods: Subjects were exercised on a cycle ergometer with increasing workloads. Minute ventilation, heart rate, breathing reserve, oxygen uptake (V’O<sub>2</sub>), O<sub>2</sub>-pulse, ventilatory equivalents for carbon dioxide and oxygen (V’<sub>E</sub>/V’CO<sub>2</sub> and V’<sub>E</sub>/V’O<sub>2</sub>, respectively) were measured at baseline and peak exercise. The slope and intercept for V’<sub>E</sub>/V’CO<sub>2</sub> was computed for all subjects. Peak V’O<sub>2</sub> 4% predicted indicated a circulatory or ventilatory limitation. Results: Complete clinical and physiological data were available for 36 patients (M/F 20/16);32 (89%) exhibited ventilatory or circulatory limitation as shown by a reduced peak V’O<sub>2</sub> and 10 subjects with normal physiologic data. The largest cohort comprised the pulmonary vascular group (n = 18) whose mean ± SD peak V’O<sub>2</sub> was 61% ± 17% predicted. There were close associations between V’O<sub>2</sub> and spirometric values. Peak V’<sub>E</sub>/V’O<sub>2</sub> and V’<sub>E</sub>/V’CO<sub>2</sub> were highest in the circulatory and ventilatory cohorts, consistent with increase in dead space breathing. The intercept of the V’<sub>E</sub>-V’CO<sub>2</sub> relationship was lowest in patients with cardiovascular impairment. Conclusion: Dyspneic patients with malignancies exhibit dead space breathing, many exhibiting a circulatory source for exercise limitation with a prominent pulmonary vascular component. Potential factors include effects of chemo- and radiation therapy on cardiac function and pulmonary vascular endothelium.
基金supported by the National Science and Technology Major Project(No.2013ZX07314-001)
文摘In wastewater treatment plants(WWTPs)using the activated sludge process,two methods are widely used to improve aeration efficiency — use of high-efficiency aeration devices and optimizing the aeration control strategy. Aeration efficiency is closely linked to sludge characteristics(such as concentrations of mixed liquor suspended solids(MLSS)and microbial communities)and operating conditions(such as air flow rate and operational dissolved oxygen(DO)concentrations). Moreover,operational DO is closely linked to effluent quality. This study,which is in reference to WWTP discharge class A Chinese standard effluent criteria,determined the growth kinetics parameters of nitrifiers at different DO levels in small-scale tests. Results showed that the activated sludge system could meet effluent criteria when DO was as low as 0.3 mg/L,and that nitrifier communities cultivated under low DO conditions had higher oxygen affinity than those cultivated under high DO conditions,as indicated by the oxygen half-saturation constant and nitrification ability. Based on nitrifier growth kinetics and on the oxygen mass transfer dynamic model(determined using different air flow rate(Q′air)and mixed liquor volatile suspended solids(MLVSS)values),theoretical analysis indicated limited potential for energy saving by improving aeration diffuser performance when the activated sludge system had low oxygen consumption; however,operating at low DO and low MLVSS could significantly reduce energy consumption. Finally,a control strategy coupling sludge retention time and MLVSS to minimize the DO level was discussed,which is critical to appropriate setting of the oxygen point and to the operation of low DO treatment technology.
基金Supported by Integrated Chinese Medicine Holdings Ltd.,HongKong,China
文摘Objective:To determine whether the ingestion of a herbal supplement called Rhodiola-Gingko Capsule(RGC) would enhance the endurance performance of healthy volunteers and change relevant hormones in a favorable manner.Methods:Seventy healthy male volunteers(age ranges from 18 to 22 years old) were randomly assigned to RGC group(35 cases,each capsule containing 270 mg herbal extracts,4 capsules per day) or placebo group(35 cases,equivalent placebo preparation) for 7 weeks using computerproduced digital random...
文摘Beijing will host the 2022 Winter Olympics,and China strengthens research on various aspects to allow their athletes to compete successfully in winter sport.Simultaneously,Government-directed initiatives aim to increase public participation in recreational winter sport.These parallel developments allow research to advance knowledge and understanding of the physiological determinants of performance and health related to winter sport.Winter sport athletes often conduct a substan-tial amount of training with high volumes of low-to-moderate exercise intensity and lower volumes of high-intensity work.Moreover,much of the training occur at low ambient temperatures and winter sport athletes have high risk of developing asthma or asthma-related conditions,such as exercise-induced bronchoconstriction.The high training volumes require optimal nutrition with increased energy and dietary protein requirement to stimulate muscle protein synthesis response in the post-exercise period.Whether higher protein intake is required in the cold should be investigated.Cross-country ski-ing is performed mostly in Northern hemisphere with a strong cultural heritage and sporting tradition.It is expected that innovative initiatives on recruitment and training during the next few years will target to enhance performance of Chinese athletes in classical endurance-based winter sport.The innovation potential coupled with resourcing and population may be substantial with the potential for China to become a significant winter sport nation.This paper discusses the physiological aspects of endurance training and performance in winter sport highlighting areas where innovation may advance in athletic performance in cold environments.In addition,to ensure sustainable development of snow sport,a quality ski patrol and rescue system is recommended for the safety of increasing mass participation.
文摘Purpose To challenge current conventions in paediatric sport science and use data from recent longitudinal studies to elu-cidate the development of aerobic and anaerobic fitness,with reference to youth athletes.Methods(1)To critically review the traditional practice of ratio scaling physiological variables with body mass and,(2)to use multiplicative allometric models of longitudinal data,founded on 1053(550 from boys)determinations of 10-17-year-olds’peak oxygen uptake(VO2)and 763(405 from boys)determinations of 11-17-year-olds’peak power output(PP)and mean power output(MP),to investigate the development of aerobic and anaerobic fitness in youth.Results The statistical assumptions underpinning ratio scaling of physiological variables in youth are seldom met.Multiplicative allometric modelling of longitudinal data has demonstrated that fat free mass(FFM)acting as a surrogate for active muscle mass,is the most powerful morphological influence on PP,MP,and peak VO2.With FFM appropriately controlled for,age effects remain significant but additional,independent effects of maturity status on anaerobic and aerobic fitness are negated.Conclusions Ratio scaling of physiological variables with body mass is fallacious,confounds interpretation of the develop-ment of anaerobic and aerobic fitness,and misleads fitness comparisons within and across youth sports.Rigorous evalua-tion of the development of anaerobic and aerobic fitness in youth requires longitudinal analyses of sex-specific,concurrent changes in age-and maturation-driven morphological covariates.Age and maturation-driven changes in FFM are essential considerations when evaluating the physiological development of youth athletes.
文摘Purpose The purpose was to investigate whether an increased amount of training while carrying the rifle affects skiing in well-trained biathletes at submaximal and maximal workloads during a pre-season period lasting a minimum of 12 weeks.Methods Seventeen well-trained biathletes(9 females,8 males)were assigned to an intervention(IG,n=10)or control(CG,n=7)group.Before(T1)and after(T2)the training intervention all participants performed,using treadmill roller-skiing,a submaximal test without the rifle on one day and two submaximal workloads and a maximal time trial(TT)with the rifle on a subsequent day.Between T1 and T2 all participants performed a minimum of 12 weeks of normal training,the only difference between groups being that IG performed more of their training sessions carrying the rifle.Results IG performed more training compared to CG(15.4±1.1 vs.11.2±2.6 h/week,P<0.05),including a higher amount of training with the rifle(3.1±0.6 vs.1.1±0.3 h/week,P<0.001).Speed at 4 mmol/L of blood lactate increased significantly for CG from T1 to T2(P=0.028),while only tended to increase for IG(P=0.058).Performance during the TT,VO2max and the aerobic metabolic rate increased significantly from T1 to T2,although the differences disappeared when including the speed at baseline as a covariate.Conclusion According to the present results,increasing training while carrying the rifle by 2 h/week does not appear to improve skiing performance in well-trained biathletes.In addition,physiological markers at submaximal and maximal intensities while carrying the rifle were not affected after the training intervention.
文摘Increased cardiovascular fitness,VO_(2max),is associated with enhanced endurance capacity and a decreased rate of mortality.High intensity interval training(HIIT)is one of the best methods to increase VO_(2max)and endurance capacity for top athletes and for the general public as well.Because of the high intensity of this type of training,the adaptive response is not restricted to Type I fibers,as found for moderate intensity exercise of long duration.Even with a short exercise duration,HIIT can induce activation of AMPK,PGC-1α,SIRT1 and ROS pathway as well as by the modulation of Ca^(2+)homeostasis,leading to enhanced mitochondrial biogenesis,and angiogenesis.The present review summarizes the current knowledge of the adaptive response of HIIT.
基金supported by the National Natural Science Foundation of China (Nos. 51878539, 52070149)the Technology Innovation and Level Promotion Project of Shanghai State-owned Assets Supervision and Administration Commission (No. 2018001)。
文摘Respirogram technology has been widely applied for aerobic process, however, the response of respirogram to anoxic denitrification is still unclear. To reveal such response may help to design a new method for the evaluation of the performance of denitrification. The size distribution of flocs measured at different denitrification moments demonstrated a clear expansion of flocs triggered by denitrification, during which higher specific endogenous and quasi-endogenous respiration rates(SOUReand SOURq) were also observed. Furthermore,SOURqincreases exponentially with the specific denitrification rate(SDNR), suggesting that there should be a maximum SDNR in conventional activated sludge systems. Based on these findings, an index Rq/t, defined as the ratio of quasi-endogenous(OURq) to maximum respiration rate(OURt), is proposed to estimate the denitrification capacity that higher Rq/tindicates higher denitrification potential, which can be readily obtained without complex measurement or analysis, and it offers a novel and promising respirogram-based approach for denitrification estimation and control by taking measures to extend anoxic time to maintain its value at a high level within a certain range.
基金This work was supported by the Ministry of Science and Technology of China(Grant No.2002DFBA0009)。
文摘This work aims to explore a procedure to improve biological wastewater treatment efficiency using low inten-sity ultrasound.The aerobic activated sludge from a munici-pal wastewater treatment plant was used as the experimental material.Oxygen uptake rate(OUR)of the activated sludge(AS)was determined to indicate the changes of AS activity stimulated by ultrasound at 35 kHz for 0-40 min with ultrasonic intensities of 0-1.2 W/cm^(2).The highest OUR was observed at the ultrasonic intensity of 0.3 W/cm^(2) and an irradiation period of 10 min;more than 15%increase was achieved immediately after sonication.More significantly,the AS activity stimulated by ultrasound could last 24 h after sonication,and the AS activity achieved its peak value within 8 h after sonication,or nearly 100%higher than the initial level after sonication.Therefore,to improve the wastewater treatment efficiency of bioreactors,ultrasound with an intensity of 0.3 W/cm^(2) could be employed to irradiate a part of the AS in the bioreactor for 10 min every 8 h.
基金the National Key Science and Technology Special Projects(No.2008ZX07209-003)Funding Project for Academic Human Resources Development in Institutions of Higher Learning under the Jurisdiction of Beijing Municipality(No.PHR20090502).
文摘In this study,an anaerobic/anoxic/oxic(A^(2)O)wastewater treatment process was implemented to treat domestic wastewater with short-term atrazine addition.The results provided an evaluation on the effects of an accidental pollution on the operation of a wastewater treatment plant(WWTP)in relation to Chemical Oxygen Demand(COD)and biological nutrient removal.Domestic wastewater with atrazine addition in 3 continuous days was treated when steady biological nutrient removal was achieved in the A^(2)O process.The concentrations of atrazine were 15,10,and 5 mg%L–1 on days 1,2 and 3,respectively.The results showed that atrazine addition did not affect the removal of COD.The specific NH4þoxidation rate and NO3–reduction rate decreased slightly due to the short-term atrazine addition.However,it did not affect the nitrogen removal due to the high nitrification and denitrification capacity of the system.Total nitrogen(TN)removal was steady,and more than 70%was removed during the period studied.The phosphorus removal rate was not affected by the short-term addition of atrazine under the applied experimental conditions.However,more poly-hydroxy-alkanoate(PHA)was generated and utilized during atrazine addition.The results of the oxygen uptake rate(OUR)showed that the respiration of nitrifiers decreased significantly,while the activity of carbon utilizers had no obvious change with the atrazine addition.Atrazine was not removed with the A^(2)O process,even via absorption by the activated sludge in the process of the short-term addition of atrazine.
文摘Objective The purpose of the present study was to investigate the association between cardiorespiratory fitness(CRF)measured as peak oxygen uptake(VO_(2peak),expressed in mL/min)and body mass index(BMI)in a large cohort of apparently healthy subjects.Methods BMI and VO_(2peak)were measured in a cross-sectional study of 8470 apparently healthy adults.VO_(2peak)(mL/min)was determined by an incremental cycle ergometer test to exhaustion.Linear regression analyses were performed to identify predictors of CRF.Results There was no difference in CRF between adults with a normal weight(BMI between 18.5-24.9 kg/m^(2))and those who were overweight(BMI 25.0-29.9 kg/m^(2)).Subjects who were underweight(BMI<18.5 kg/m^(2))as well as females who were obese(BMI≥30.0 kg/m^(2))showed a reduced CRF compared to the normal and overweight groups.Age,height,and gender were significant predictors of CRF(R^(2)=0.467,P<0.0001);BMI did not add significantly to this relationship.Conclusion Our findings indicate that BMI was not associated with CRF in addition to age,height,and gender.In subjects with a BMI<18.5 kg/m^(2),CRF was lower compared to subjects with a BMI between 18.5 and 29.9 kg/m^(2).In obese subjects,CRF was only lower in females compared to females with a BMI between 18.5 and 29.9 kg/m^(2).Correcting CRF for BMI may be beneficial for subjects with a low BMI,and females with a BMI≥30.0 kg/m^(2).The outcome of this study might help to improve the interpretation of exercise testing results in individuals with a low or high BMI.