Objective: Despite the common occurrence of lower levels of physical activity and physical fitness in youth with spina bifida (SB) who use a wheelchair, there are very few tests available to measure and assess these levels. The purpose of this study was to determine reliability and the physiologic response of the 6-minute push test (6MPT) in youth with SB who self-propel a wheelchair. Methods: In this reliability and observational study, a sample of 53 youth with SB (5-19 years old; mean age = 13 years 7 months; 32 boys and 21 girls) who used a wheelchair performed 2 exercise tests: the 6MPT and shuttle ride test. Heart rate, minute ventilation, respiratory exchange ratio, and oxygen consumption were measured using a calibrated mobile gas analysis system and a heart rate monitor. For reliability, intraclass correlation coefficients (ICCs), SE of measurement, smallest detectable change for total covered distance, minute work, and heart rate were calculated. Physiologic response during the 6MPT was expressed as percentage of maximal values achieved during the shuttle ride test. Results: The ICCs for total distance and minute work were excellent (0.95 and 0.97, respectively), and the ICC for heart rate was good (0.81). The physiologic response during the 6MPT was 85% to 89% of maximal values, except for minute ventilation (70.6%). Conclusions: For most youth with SB who use a wheelchair for mobility or sports participation, the 6MPT is a reliable, functional performance test on a vigorous level of exercise. Impact: This is the first study to investigate physiologic response during the 6MPT in youth (with SB) who are wheelchair using. Clinicians can use the 6MPT to evaluate functional performance and help design effective exercise programs for youth with SB who are wheelchair using. Keywords: 6-minute push test; adolescent; disabled children; spinal diseases; wheelchairs.
BACKGROUND: Near-infrared spectroscopy (NIRS) measurements of oxygenation reflect O2 delivery and utilization in exercising muscle and may improve detection of a critical exercise threshold.PURPOSE: First, to detect an oxygenation breakpoint (Δ[O2HbMb-HHbMb]-BP) and compare this breakpoint to ventilatory thresholds during a maximal incremental test across sexes and training status. Second, to assess reproducibility of NIRS signals and exercise thresholds and investigate confounding effects of adipose tissue thickness on NIRS measurements.METHODS: Forty subjects (10 trained male cyclists, 10 trained female cyclists, 11 endurance trained males and 9 recreationally trained males) performed maximal incremental cycling exercise to determine Δ[O2HbMb-HHbMb]-BP and ventilatory thresholds (VT1 and VT2). Muscle haemoglobin and myoglobin O2 oxygenation ([HHbMb], [O2HbMb], SmO2) was determined in m. vastus lateralis. Δ[O2HbMb-HHbMb]-BP was determined by double linear regression. Trained cyclists performed the maximal incremental test twice to assess reproducibility. Adipose tissue thickness (ATT) was determined by skinfold measurements.RESULTS: Δ[O2HbMb-HHbMb]-BP was not different from VT1, but only moderately related (r = 0.58-0.63, p<0.001). VT1 was different across sexes and training status, whereas Δ[O2HbMb-HHbMb]-BP differed only across sexes. Reproducibility was high for SmO2 (ICC = 0.69-0.97), Δ[O2HbMb-HHbMb]-BP (ICC = 0.80-0.88) and ventilatory thresholds (ICC = 0.96-0.99). SmO2 at peak exercise and at occlusion were strongly related to adipose tissue thickness (r2 = 0.81, p<0.001; r2 = 0.79, p<0.001). Moreover, ATT was related to asymmetric changes in Δ[HHbMb] and Δ[O2HbMb] during incremental exercise (r = -0.64, p<0.001) and during occlusion (r = -0.50, p<0.05).CONCLUSION: Although the oxygenation threshold is reproducible and potentially a suitable exercise threshold, VT1 discriminates better across sexes and training status during maximal stepwise incremental exercise. Continuous-wave NIRS measurements are reproducible, but strongly affected by adipose tissue thickness.
Background: Patients with Senning repair for complete transposition of the great arteries (d-TGA) show an impaired exercise tolerance. Our aim was to investigate changes in exercise capacity in children, adolescents and adults with Senning operation. Methods: Peak oxygen uptake (peak VO2), oxygen pulse and heart rate were assessed by cardiopulmonary exercise tests (CPET) and compared to normal values. Rates of change were calculated by linear regression analysis. Right ventricular (RV) function was assessed by echocardiography. Results: Thirty-four patients (22 male) performed 3.5 (range 3–6) CPET with an interval of ≥ 6 months. Mean age at first assessment was 16.4 ± 4.27 years. Follow-up period averaged 6.8 ± 2 years. Exercise capacity was reduced (p<0.0005) and the decline of peak VO2 (−1.3 ± 3.7 %/year; p=0.015) and peak oxygen pulse (−1.4 ± 3.0 %/year; p=0.011) was larger than normal, especially before adulthood and in female patients (p<0.01). During adulthood, RV contractility changes were significantly correlated with the decline of peak oxygen pulse (r= −0.504; p=0.047). Conclusions: In patients with Senning operation for d-TGA, peak VO2 and peak oxygen pulse decrease faster with age compared to healthy controls. This decline is most obvious during childhood and adolescence, and suggests the inability to increase stroke volume to the same extent as healthy peers during growth. Peak VO2 and peak oxygen pulse remain relatively stable during early adulthood. However, when RV contractility decreases, a faster decline in peak oxygen pulse is observed
Green methanol is emerging as a key player in sustainable biotech, offering a renewable alternative to fossil fuels or sugar based feedstocks. Although methanol has long been considered a promising material for bioproduction, using it on industrial scale has been challenging due to its high oxygen demands, making the process expensive and inefficient. This project focuses on developing a sustainable, but more economical feasible way to produce biochemicals, like Single Cell Protein (SCP). The innovative solution proposed by FeedstocksUnited (FSU) is to use paraformaldehyde, a compound derived from renewable methanol, as feedstock, which requires much less oxygen during fermentation. This new method has already shown promising results in the lab, where it was tested with microorganisms that can use formaldehyde (released from paraformaldehyde) as a source of carbon and energy. FSU’s approach has the potential to significantly reduce the costs and environmental impacts associated with large-scale bioproduction. The process can be managed more efficiently than methods using methanol, since the production of paraformaldehyde from formaldehyde is tunable. This process control will lead to better yields and reduced energy and feedstock consumption. The HAN BioCentre, with its advanced research facilities and experienced team, will conduct further research to optimize this method for industrial applications. This includes studying how organisms metabolize formaldehyde and improving the process through continuous fermentation. The research also supports educational goals by involving students in cutting-edge biotechnological work. Ultimately, the project aims to provide a solid proof-of-concept that can be scaled up to industrial levels, contributing to a more sustainable bioeconomy.
The EU Climate and Energy Policy Framework targets a 40% reduction in Greenhouse Gases (GHGs) emission by companies (when compared to 1990’s values) in 2030 [1]. Preparing for that future, many companies are working to reach climate neutrality in 2030. For water and wastewater treatment plants aeration processes could represent up to 70% of the whole energy consumption of the plant. Thus, a process which must be carefully evaluated if climate neutrality is a target. VortOx is an alternative to reduce power consumption in aeration processes. It is structured to test the applicability of geometrically constrained vortices in a hyperbolic funnel (aka “Schauberger”- funnel) as an innovative aeration technique for this industry. Recent investigations have shown that such systems allow an average of 12x more oxygen transfer coefficients (KLa) than that of comparable methods like air jets or impellers [10]. However, the system has a relatively small hydraulic retention time (HRT), which compromises its standard oxygen transfer ratio (SOTR). Additionally, so far, the system has only been tested in pilot (lab) scale. Vortox will tackle both challenges. Firstly, it will test geometry and flow adaptations to increase HRT keeping the same KLa levels. And secondly, all will be done using a real scale hyperbolic funnel and real effluent from Leeuwarden’s wastewater treatment plant demo-site. If proven feasible, Vortox can be a large step towards climate neutral water and wastewater treatment systems.
