Cycle Endurance Test Research Articles

Usefulness of the Constant load Cycle Endurance Test in patients with Lung Cancer during Radiation Therapy

Usefulness of the Constant load Cycle Endurance Test in patients with Lung Cancer during Radiation Therapy

High-intensity non-invasive ventilation during exercise-training versus without in people with very severe COPD and chronic hypercapnic respiratory failure: a randomised controlled trial

BackgroundPeople with very severe chronic obstructive pulmonary disease (COPD) using nocturnal non-invasive ventilation (NIV) for chronic hypercapnic respiratory failure (CHRF) experience reduced exercise capacity and severe dyspnoea during exercise training...

Highly compatible and reliable ZrN interfacial layer between TiN top electrode and antiferroelectric ZrO2 thin film to boost the electrocaloric behavior

A highly compatible and reliable ZrN interfacial layer with different cycles of atomic layer deposition was inserted between the TiN top electrode and antiferroelectric (AFE) ZrO2 thin film to achieve low oxygen vacancies and high crystallinity of the ZrO2 thin film, boosting the AFE and electrocaloric (EC) characteristics of TiN/ZrO2/TiN metal–insulator–metal (MIM) capacitors. An outstanding adiabatic temperature change (ΔT) of − 21 K was realized for devices with a ZrN interfacial layer of nine cycles, which can be ascribed to the reduction in redox between the TiN and ZrO2 for the suppression of interfacial dead layer during annealing as confirmed via high-angle annular dark field images and interfacial capacitance measurement. Hence, the reliability of ZrO2 MIM capacitors with a nine-cycle ZrN interfacial layer was examined with a negligible change in AFE and EC behaviors after a cycling endurance test of 106 cycles, exhibiting great potential for future applications in solid-state cooling.

Motivational self-talk mitigates the harmful impact of mental fatigue on endurance performance

In sports, athletes might train or compete with some degree of mental fatigue that has an impact on performance. The present study investigated the effect of strategic motivational self-talk on endurance performance in mentally fatigued individuals. Twelve healthy men performed three cycling endurance tests at 80% peak power output until exhaustion. Two experimental conditions (mental fatigue [MF] and mental fatigue plus motivational self-talk [MF + M−ST]) and a control condition (CO) were set out. Mental fatigue was induced via 30 min Stroop task; an electroencephalogram of the frontal cerebral cortex was continually monitored. Affective state and perceived exertion were recorded during each session and subjective workload after the endurance exercise trials. Theta band power spectral density was significantly higher in both experimental condition (MF and MF + M−ST) compared to CO, without significant differences between MF and MF + M−ST. Endurance performance was significantly worse in MF (227 ± 63s) than in CO (329 ± 84s). However, motivational self-talk reversed the deleterious effect of MF on endurance performance as in MF + M−ST (368 ± 139s) it was significantly better than MF and not significantly different from CO. Displeasure and perceived exertion scores were similar at the end of exercise and presented similar rate of increase among conditions. Mental demand after exercise was significantly greater in MF than in CO condition. These results suggest that motivational self-talk mitigates the negative effect of MF on endurance performance due to an elevated engagement with the task. Lay summary: This study examined to what extent the deliberate and planned use of cue words to enhance motivation (i.e., motivational self-talk), influenced endurance performance in mentally fatigued individuals. The harmful impact of mental fatigue on endurance performance was mitigated by using motivational self-talk during cycling exercise.

The effects of inspiratory muscle training with pulmonary rehabilitation on NSCLC patients during radiation therapy: A pilot clinical study.

The effects of inspiratory muscle training (IMT) with pulmonary rehabilitation (PR) on patients with non-small cell lung cancer (NSCLC) receiving radiotherapy (RT) have not previously been reported. This pilot study aimed to determine the effectiveness of IMT with PR on respiratory muscles and exercise capacity of NSCLC patients receiving RT. We retrospectively analyzed 20 patients who underwent RT for NSCLC. The rehabilitation included IMT, stretching, strengthening, and aerobic exercises three times a week for 4 weeks with concurrent RT. IMT training lasted 10 min, consisting of one cycle of 30 breaths using the Powerbreathe KH1 device in the hospital by a physical therapist. Patients underwent two IMT sessions at home daily at an intensity of approximately 30%-50% of the participant's maximum inspiratory muscle pressure (MIP) using the threshold IMT tool. We analyzed the results from the respiratory muscle strength test, pulmonary function test, 6-min walk test (6MWT), cardiopulmonary function test, cycle endurance test (CET), Inbody test, grip measurement, knee extensor/flexor strength measurement, Cancer Core Quality of Life Questionnaire (EORTCQ-C30), and NSCLC 13 (EORTC-LC13). There were no adverse events during evaluation and IMT with PR. MIP (60.1 ± 25.1 vs. 72.5 ± 31.9, p = 0.005), 6MWT (439.2 ± 97.1 vs. 60.7 ± 97.8, p = 0.002), CET (181.39 ± 193.12 vs. 123.6 ± 87.6, p = 0.001), knee extensor (14.4 ± 5.3 vs. 17.4 ± 5, p = 0.012), and knee flexor (14.0 ± 5.2 vs. 16.9 ± 5.5, p = 0.004) significantly improved after IMT with PR. IMT with PR appears effective on respiratory muscles and exercise capacity without adverse events in NSCLC patients who underwent RT.

Thickness dependence of resistive switching characteristics of the sol–gel processed Y2O3 RRAM devices

In this study, yttrium oxide (Y2O3)-based resistive random-access memory (RRAM) devices were fabricated using the sol–gel method. The fabricated Y2O3 RRAM devices exhibited conventional bipolar RRAM device characteristics and did not require a forming process. The Y2O3 film thickness was controlled by varying the liquid-phase precursor concentration. As the concentration increased, thicker Y2O3 films were formed. In addition, the concentration of oxygen vacancies increased. The RRAM device properties were not observed for thin Y2O3 films, which had the lowest oxygen vacancy concentration. Moreover, RRAM devices, which consisted of the thickest Y2O3 films with the largest oxygen vacancy concentration, showed poor non-volatile properties. The optimized Y2O3-based RRAM devices with a thickness of 37 nm showed conventional bipolar RRAM device characteristics, which did not require an initial forming process. The fabricated RRAM devices showed a high resistance state to low resistance state ratio of over 104, less than +1.5 V of SET voltage, and −15.0 V of RESET voltage. The RRAM devices also showed promising non-volatile memory properties, without significant degradation after 103 s retention and 102 cycle endurance tests.

Study of the structure and mechanical properties of composites used in the oil and gas industry

<abstract> <p>This article describes the structure and properties of the developed hybrid composite Hastelloy X (NiCrFeMo)-AlMoNbTaTiZr-cBNSiCNiAlCo. The composite was obtained by the high velocity oxygen fuel spraying (HVOF) method in a protective atmosphere with a subsequent high-temperature thermomechanical treatment. In order to obtain new information about the structure, we studied the metallophysical properties of the composite using electron microscopy and X-ray diffraction analysis, as well as the mechanical properties and phase composition. We studied the influence of high-energy mechanical processing of high-entropic and ceramic materials on the structural-phase state and composite quality. We determined the optimal technological parameters of HVOF in a protective atmosphere, followed by a high-temperature thermomechanical treatment. Additionally, we optimized these parameters to form a hybrid composite providing the highest adhesion and low porosity. Moreover, we investigated the microhardness of the composite layers. On the basis of complex metallophysical studies, we examined the composite formation. In order to determine the endurance limit in comparison to various other composite materials, we carried out cyclic endurance tests of the developed materials.</p> </abstract>

Effect of caffeine on mitochondrial biogenesis in the skeletal muscle - A narrative review.

Caffeine is one of the most widely used substances as recreational drug for performance-enhancement in sport, underpinned by a strong evidence base. Although the effects of caffeine are widely investigated within the scope of performance physiology, the molecular effects of caffeine within skeletal muscle remain unclear. Evidence from invitro and invivo models suggest that caffeine regulates the glucose metabolism in the skeletal muscle. Moreover, caffeine seems to stimulate CaMKII, PPARδ/β, AMPK and PGC1α, classical markers of exercise-adaptations, including mitochondrial biogenesis and mitochondrial content. This review summarizes evidence to suggest caffeine-effects within skeletal muscle fibers, focusing on the putative role of caffeine on mitochondrial biogenesis to explore whether caffeine supplementation might be a strategy to enhance mitochondrial biogenesis.

Electrical characteristics investigation of ferroelectric memories using stacked and mixed hafnium zirconium oxides

• Ferroelectric characteristics of mixed and stacked HfZrO devices were investigated. • Stacked HfZrO device showed a much stronger ferroelectricity than mixed one. • A surface nitrogen plasma treatment can alleviate ferroelectric domain pinning. • Nitrogen incorporation into stacked HfZrO further improved the endurance cycling. In this work, we investigate ferroelectric characteristics of hafnium zirconium oxide (HfZrO) metal-ferroelectric-metal (MFM) devices with mixed and stacked film structure. The experimental results reveal that the stacked HfZrO MFM device has a lower dynamic leakage and stronger ferroelectric polarization value of approximately 27.3 μC/cm 2 , which is much higher than 17.5 μC/cm 2 measured from mixed HfZrO MFM device. From endurance cycling test, we also confirm that the stacked HfZrO MFM capacitor with a remote nitrogen plasma treatment featuring a large initial hysteresis window can achieve a stable operation up to 10 8 cycles at an operating voltage of 2.5 V, which is even longer than that of mixed HfZrO MFM capacitor by one order of magnitude. Therefore, the stacked MFM structure with proper interface engineering provides a promising approach for the process integration of ferroelectric memory under the comprehensive consideration of device performance and endurance.

Exploring the Impact of Mental Fatigue and Emotional Suppression on the Performance of High-Intensity Endurance Exercise

This study investigated the extent to which mental fatigue and emotional suppression affected exercise endurance. Twelve participants performed cycling endurance tests at 80% of their peak power up to the point of exhaustion. Two experimental conditions (mental fatigue [MF] and emotion suppression conditions [ES]) and a control condition (CO) were administered. Participants responded to psychological measures throughout the exercise trials. Both MF and ES conditions hindered exercise performance relative to the CO, and there was no statistically significant difference between the negative effects of both MF and ES conditions. Of note, however, higher levels of subjective fatigue were reported in MF, prior to commencing the exercise test. High cognitive loads that induce MF and/or engaging in ES may reduce high intensity endurance exercise performance among young adults, but further research with greater numbers of participants is needed to replicate and extend these findings.

A Simple Strategy to Realize Super Stable Ferroelectric Capacitor via Interface Engineering

AbstractFluorite‐structure ferroelectric thin films have been extensively studied as promising candidates for next‐generation non‐volatile memory. However, these ferroelectric thin films have fatal issues such as the irregular formation of the ferroelectric phase, low cycling endurance, and wake‐up and fatigue during endurance cycling tests. These problems are reportedly caused by oxygen vacancies, which form due to the interface reaction between the thin films and bottom electrodes during deposition and the post‐annealing process. Therefore, in this work, the enhanced ferroelectric characteristics of Hf1‐xZrxO2 thin films that control the oxygen vacancies in thin films through interfacial pretreatment are investigated. Interfacial treatment using an oxygen source can reduce oxygen vacancies and improve crystallinity through intentional oxidation of the bottom electrode. As a result, the remanent polarization value is increased by ≈1.6 times by applying the optimized pretreatment condition, and the measured 2Pr is a very high value of 73 µC cm−2. Furthermore, it exhibits very stable ferroelectric properties without a wake‐up effect or significant fatigue, up to 108 cycles even under a severe electric field of 3.5 MV cm−1. This simple strategy provides a new avenue to effectively improve the performance and cycling endurance of devices with ferroelectric thin films.

Highly Reliable Electrocaloric Behaviors of Antiferroelectric Al:ZrO2 Thin Films for Solid-State Cooling in Integrated Circuits

Heat generation in integrated circuits (ICs) has become a severe issue, which limits the utilization of miniaturized semiconductor devices in high-density 3-D IC technologies. Herein, Al₂O₃ was doped in ZrO₂ thin films by plasma-enhanced atomic layer deposition (PEALD) to enhance their antiferroelectric (AFE) characteristics for highly reliable electrocaloric (EC) cooling applications. The cycling endurance in AFE behaviors of the Al:ZrO₂ thin films under a high electric field of 5 MV/cm was significantly improved because of the enlargement of the energy bandgap with high resistance in trap-induced leakage current. Hence, the reliability of the EC effect of the 1% Al:ZrO₂ thin film was examined with a negligible change in adiabatic temperature change (Δ T) of 2.6% after a cycling endurance test of 10⁶ cycles. With the competitive cycling reliabilities in AFE and EC behaviors, devices with optimized Al₂O₃-incorporated ZrO₂ thin films show significant potential for future nanoscale cooling systems in chip-level ICs.

Effects of resistance training on exercise ability in chronic obstructive pulmonary disease subjects: A systematic review and meta-analysis.

The resistance exercise effect on the exercise ability in chronic obstructive pulmonary disease (COPD) subjects has drawn considerable attention. However, the relationship between resistance exercise and the exercise ability of COPD subjects is conflicting. This meta-analysis was performed to evaluate this relationship. A systematic-literature search up to July 2020 was performed in OVID, Embase, Cochrane Library, PubMed, Google scholar for randomised control trials reported relationships between resistance exercise and the exercise ability of COPD subjects, and 13 studies were detected with 1286 subjects at the baseline. Mean differences (MD) with 95% confidence intervals (CIs) were calculated comparing the resistance exercise and the exercise ability of COPD subjects using the continuous method with a random or fixed-effect model. A significantly higher 6-minutes walk test was observed in subjects performing resistance training (MD, 60.41; 95% CI, 39.97-80.85, P<.001) compared with non-resistance training subjects. However, no significant difference was observed between COPD subjects performing resistance exercise compared with non-resistance training COPD subjects in constant work rate cycle endurance test (MD, 1.59; 95% CI, 0.03-3.15, P=.05), unsupported upper extremity exercise test (MD, 48.77; 95% CI, -1.20 to 98.75, P<.06) and quality of life questionnaires (MD, -0.62; 95% CI, -2.49 to 1.245, P<.51). The resistance exercise significantly increases the 6-minutes walk test in COPD subjects. However, resistance exercise did not significantly affect the constant work rate cycle endurance test, unsupported upper extremity exercise test and quality of life questionnaires. This relationship forces us to recommend the resistance exercise to improve the 6-minutes walk test as a simple and easy evaluation of functional exercise ability in COPD subjects.

Benefits of pulmonary rehabilitation in COPD patients with mild cognitive impairment – A pilot study

BackgroundCognitive impairment might interfere with the efficacy of Pulmonary Rehabilitation (PR) in Chronic Obstructive Pulmonary Disease (COPD). We aimed to identify differential responses to PR between cognitively impaired (CI) and cognitively normal (CN) COPD patients by assessing health status and exercise capacity. MethodsSixty patients (FEV1: 47 ± 15%) were classified as CI or CN according to the Montreal Cognitive Assessment (MoCA ≤25points) and completed a 3-week inpatient PR program. Cognitive function (neuropsychological battery), health-status (36-Item Short Form Survey [SF-36]), and exercise capacity (6-min walk test [6MWT], cycle-endurance test [CET]) were assessed before and after PR. Responsiveness to PR was estimated by mean change (delta-value [Δ]) and the d-Effect Size (ES). ResultsTwenty-five COPD patients (42%) presented evidence of mild CI prior to PR. Both, CI and CN patients significantly improved global cognitive function, health status (the majority of SF-36 components), and exercise capacity (6MWT and cycle endurance) in response to PR. Compared to CN, CI patients did not improve SF-36 subdomains of “role emotional” and “bodily pain”, and demonstrated a lower magnitude of improvement in 6MWT ([Δ]: 25 m; ES: 0.21) compared to CN ([Δ]: 46 m; ES: 0.54). ConclusionsPR has favorable effects on global cognitive function, health status, and exercise capacity in both CI and CN COPD patients. There was no concrete evidence to indicate interference of cognitive impairment to PR effectiveness.

Six Sessions of Sprint-Interval Training Did Not Improve Endurance and Neuromuscular Performance in Untrained Men.

Previous research demonstrated that six sessions of cycling sprint-interval training (SIT) within a duration of only 2 weeks can increase endurance performance considerably. Primarily muscular mechanisms have been under investigation explaining such performance improvements. However, it has been shown in other exercise tasks that training-induced changes also occur at the level of the central nervous system. Therefore, we hypothesized to observe an enhanced neuromuscular performance in conjunction with an increase in endurance performance after 2 weeks of SIT. Therefore, we randomly assigned 19 healthy men (26 ± 5 years) to a control (n = 10) or a training group (n = 9), the latter performing a replication of the SIT protocol from Burgomaster et al. Before and after the training intervention, both groups performed a cycling endurance test until exhaustion. Neuromuscular function of the right vastus lateralis muscle was assessed before and after each endurance task by the means of maximal voluntary isometric contractions (MVCs). The variables of interest being MVC, voluntary activation was measured by peripheral nerve stimulations (VAPNS), by transcranial magnetic stimulation (VATMS), as well as potentiated resting twitches (Qtw,pot). We did not find any significant differences between the groups in the control variable time to exhaustion in the endurance task. In addition, we did not observe any time × group interaction effect in any of the neuromuscular parameters. However, we found a significant large-sized time effect in all neuromuscular variables (MVC, = 0.181; VATMS, = 0.250; VAPNS, = 0.250; Qtw,pot, = 0.304) as well as time to exhaustion = 0.601). In contrast to other studies, we could not show that a short-term SIT is able to increase endurance performance. An unchanged endurance performance after training most likely explains the lack of differences in neuromuscular variables between groups. These findings demonstrate that replication studies are needed to verify results no matter how strong they seem to be. Differences over time for the variables of neuromuscular fatigue irrespective of group (MVC, + 9.3%; VATMS, + 0.2%; VAPNS, + 6.3%; Qtw,pot, + 6.3%) demonstrate test-retest effects that should be taken into consideration in future training studies and emphasize the inevitable necessity for controlled experiments.

Effects of a commercially available branched-chain amino acid-alanine-carbohydrate-based sports supplement on perceived exertion and performance in high intensity endurance cycling tests

BackgroundSports nutritional supplements containing branched-chain amino acids (BCAA) have been widely reported to improve psychological and biological aspects connected to central fatigue and performance in endurance exercise, although the topic is still open to debate. The aim of the present study was to determine whether the intake of a commercially available BCAA-based supplement, taken according to the manufacturer’s recommendations, could affect the rating of perceived exertion (RPE) and performance indexes at the beginning (1d) and end of a 9-week (9w) scheduled high intensity interval training program, with an experimental approach integrating the determination of psychometric, performance, metabolic and blood biochemical parameters.MethodsThis was a randomized double-blind placebo-controlled study. Thirty-two untrained, healthy young adults (20 males and 12 female) were enrolled. A high-intensity endurance cycling (HIEC) test was used to induce fatigue in the participants: HIEC consisted in ten 90 s sprints interspersed by ten 3 min recovery phases and followed by a final step time to exhaustion was used. In parallel with RPE, haematological values (creatine kinase, alanine, BCAA, tryptophan, ammonia and glucose levels), and performance indexes (maximal oxygen consumption - VO2max, power associated with lactate thresholds - WLT1, WLT2 and time to exhaustion - TTE) were assessed. All subject took the supplement (13.2 g of carbohydrates; 3.2 g of BCAA and 1.6 g of L-alanine per dose) or placebo before each test and training session. Dietary habits and training load were monitored during the entire training period.ResultsThe administration of the supplement (SU) at 1d reduced RPE by 9% during the recovery phase, as compared to the placebo (PL); at 9w the RPE scores were reduced by 13 and 21% during the sprint and recovery phase, respectively; at 9w, prolonged supplement intake also improved TTE and TRIMP. SU intake invariably promoted a rapid increase (within 1 h) of BCAA serum blood levels and prevented the post-HIEC tryptophan: BCAA ratio increase found in the PL group, at both 1d and 9w. There was no difference in dietary habits between groups and those habits did not change over time; no difference in glycemia was found between SU and PL. VO2max, WLT1 and WLT2 values improved over time, but were unaffected by supplement intake.ConclusionsOn the whole, these results suggest that i) the intake of the BCAA-based commercially available supplement used in this study reduces RPE as a likely consequence of an improvement in the serum tryptophan: BCAA ratio; ii) over time, reduced RPE allows subjects to sustain higher workloads, leading to increased TRIMP and TTE.

Printable Stretchable Silver Ink and Application to Printed RFID Tags for Wearable Electronics.

A printable elastic silver ink has been developed, which was made of silver flakes, dispersant, and a fluorine rubber and could be sintered at a low temperature. The printed elastic conductors showed low resistivity at 21 μΩ·cm, which is about 13.2 times of bulk silver (1.59 μΩ·cm). Their mechanical properties were investigated by bending, stretching, and cyclic endurance tests. It was found that upon stretching the resistance of printed conductors increased due to deformation and small cracks appeared in the conductor, but was almost reversible when the strain was removed, and the recovery of conductivity was found to be time dependent. Radio-frequency identification (RFID) tags were fabricated by screen printing the stretchable silver ink on a stretchable fabric (lycra). High performance of tag was maintained even with 1000 cycles of stretching. As a practical example of wearable electronics, an RFID tag was printed directly onto a T-shirt, which demonstrated its normal working order in a wearing state.

Power cycling and temperature endurance test of a GaN switching cell with substrate integrated chips

We present a reliability study of a half-bridge switching cell with substrate integrated 650 V GaN HEMTs. Power Cycling Testing with a ΔTj of 100 K has revealed thermo-mechanically induced failures of contact vias after more than 220 kcycles. The via failure mode of contact opening is confirmed by reverse-bias pulsed IV-measurements to be primarily triggered by a ΔTj imposed thermal gradient and not by a high Tj. The chip electrical characteristics, however, remained unaffected during Power Cycling. Furthermore, a High Temperature Storage test at 125 °C for 5000 h has shown no changes in the electrical performance of substrate integrated GaN HEMTs.

SUN-PO317: Effects of a Branched-Chain Amino Acids-Alanine-supplementation Intake in High Intensity Endurance Cycling Tests

SUN-PO317: Effects of a Branched-Chain Amino Acids-Alanine-supplementation Intake in High Intensity Endurance Cycling Tests

Investigation on polarization characteristics of ferroelectric memories with thermally stable hafnium aluminum oxides

In this work, we successfully demonstrated the 9.6-nm-thick HfAlOx ferroelectric memory using light aluminium doping of 6.5% to form ferroelectric orthorhombic phase. Compared to ferroelectric HfZrOx film with zirconium diffusion issue, the HfAlOx film showed excellent thermal stability under high temperature annealing. Besides, the ferroelectric HfAlOx also exhibited robust polarization characteristics under endurance cycling test. A >106 stressed cycles with 4 MV/cm can be measured and a long endurance was sustained over 5 × 107 cycles under 3.6 MV/cm. Therefore, the HfAlOx film showed the great promise for integrating in high performance ferroelectric memory with thermal budget concerns.