Search

The current study employed a within-participant design to analyze the effects of head movements in three conditions (i.e., head nodding, head shaking, and no head movements) during positive (motivational) self-talk among 22 male cyclists. After the self-talk and head-movements task, physical performance (i.e., anaerobic power) was assessed using a Wingate Test for each experimental condition. Each cyclist participated individually on three separate days, completing one of the three experimental conditions each day. We hypothesized and found that the head-nodding condition resulted in greater physical performance (i.e., mean and peak power) than the no-head-movements condition. This is the first time that head nodding has been shown to improve physical performance compared with no head movements during encouraging and self-assuring self-talk. Relevantly, these findings emphasize the importance of focusing on athletes' nonverbal behavior (e.g., head movements) when engaging in positive (motivational) self-talk to perform better. [ABSTRACT FROM AUTHOR]

The application of solid-state electrolytes in Li batteries is hampered by the occurrence of Li-dendrite-caused short circuits. To avoid cell failure, the electrolytes can only be stressed with rather low current densities, severely restricting their performance. As grain size and pore distributions significantly affect dendrite growth in ceramic electrolytes such as Li7La3Zr2O12 and its variants; here, a "detour and buffer" strategy to bring the superiority of both coarse and fine grains into play, is proposed. To validate the mechanism, a coarse/fine bimodal grain microstructure is obtained by seeding unpulverized large particles in the green body. The rearrangement of coarse grains and fine pores is fine-tuned by changing the ratio of pulverized and unpulverized powders. The optimized bimodal microstructure, obtained when the two powders are equally mixed, allows, without extra interface decoration, cycling for over 2000 h as the current density is increased from 1.0 mA·cm-2, and gradually, up to 2.0 mA·cm-2. The "detour and buffer" effects are confirmed from postmortem analysis. The complex grain boundaries formed by fine grains discourage the direct infiltration of Li. Simultaneously, the coarse grains further increase the tortuosity of the Li path. This study sheds light on the microstructure optimization for the polycrystalline solid-state electrolytes.

Purpose: The present study aims to evaluate the effects of intermittent sequential pneumatic compression (ISPC) in the short-term recovery of a repeated sprint interval exercise, including the assessment of power output performance, hematocrit, legs water, and perceptual recovery. Methods: A randomized, counterbalanced, crossover design was conducted. Sixteen healthy trained individuals (F=7, M=9; 27.7 ± 9.4 years; BMI 22.3 ± 2.9) performed two trials of a cycling fatiguing exercise, followed by a recovery phase (ISPC or Sham), and a subsequent performance assessment exercise to evaluate the effects of ISPC in post-exercise recovery. Results: There were no significant differences in cycling performance comparing both recovery modes. However, the decrease in the hematocrit levels after the recovery phase was less exacerbated in the ISPC condition compared to Sham (44.03 ± 1.33 vs. 42.38 ± 1.33 %; p = 0.047; d = 0.310). Likewise, the total quality recovery (TQR) was higher after the recovery in the ISPC condition (15.94 ± 0.16 vs. 14.75 ± 0.12 points; p = 0.045; d = 2.125), although no differences were shown previously in power output performance (371.8 ± 22.2 [46.5] vs. 372.4 ± 21.8 [47.2] W; p = 0.986) and rating of perceived exertion (RPE) (17.69 ± 0.41 vs. 17.56 ± 0.31; p = 0.700). Conclusions: Contrary to our hypothesis, the application of intermittent sequential pneumatic compression after high-intensity exercise reduces the post-exercise hemodilution response and increases perceptual recovery. However, power output was similar between conditions, challenging the effectiveness of this recovery method in a short-term intervention. [ABSTRACT FROM AUTHOR]

The PPy-coated Na 0.67 Ni 0.33 Mn 0.67 O 2 cathode undergoes reversible structural evolution during charging/discharging process. The Na-ion full cell exhibits a high capacity retention of 88.2% after 150 cycles. [Display omitted] • PPy-coated P 2-Na 0.67 Ni 0.33 Mn 0.67 O 2 is prepared by in situ polymerization process. • The PPy-coated cathode showed enhanced cycling stability and rate capability. • The PPy coating layer can inhibit side reactions stemming from the electrolyte. P 2-Na 0.67 Mn 0.67 Ni 0.33 O 2 is a promising cathode material for sodium ion batteries (SIBs) due to its low cost, high theoretical capacity, and non-toxicity. However, it still suffers from unsatisfactory cycling stability mainly incurred by the Jahn-Teller effect of Mn3+ and electrolyte decomposition on the electrode/electrolyte interface. Herein, the P 2-Na 0.67 Ni 0.33 Mn 0.67 O 2 @PPy (NNMO@PPy) composite applied as cathode materials for SIBs is obtained by introducing conductive polypyrrole (PPy) as coating layer on the P 2-Na 0.67 Ni 0.33 Mn 0.67 O 2 (NNMO) microspheres. Numerous physical characterization methods indicate that the PPy layer was uniformly coated on the surface of NNMO microspheres without change in phase structure and morphology. The PPy coating layer can alleviate Mn dissolution and effectively suppress the side reactions between the electrolyte and electrode during cycling. The optimal NNMO@PPy-9 with 9 wt% PPy delivers a high capacity of 127.4 mAh/g at the current density at 150 mA g−1, an excellent cyclic stability with high capacity retention of 80.5 % after 300 cycles, and enhanced rate performance (169.3 mAh/g at 15 mA g−1 while 89.8 mAh/g at 600 mA g−1). Furthermore, hard carbon (−)//NNMO@PPy-9 (+) full cell delivers a high energy density of 305.1 Wh kg−1 and superior cycling stability with 88.2 % capacity retention after 150 cycles. In-situ X-ray diffraction experiment and electrochemical characterization verify the highly reversible structure evolution and robust P 2-type phase structure of NNMO@PPy-9 for fast and stable Na+ diffusion. This effective strategy of using conductive PPy as a coating layer may provide a new insight to modify NNMO surface, improving the cycling stability and rate capability. [ABSTRACT FROM AUTHOR]

Self-paced exercise protocols have gained attention for their potential to optimize performance and manage fatigue by allowing individuals to regulate their efforts based on perceived exertion. This pilot study aimed to investigate the neural and physiological responses during a self-paced V ˙ O2max (SPV) and incremental exercise tests (IET). Six trained male cyclists (mean age 39.2 ± 13.3 years; V ˙ O2max 54.3 ± 8.2 mL·kg−1·min−1) performed both tests while recording their brain activity using electroencephalography (EEG). The IET protocol involved increasing the power every 3 min relative to body weight, while the SPV allowed participants to self-regulate the intensity using ratings of perceived exertion (RPE). Gas exchange, EEG, heart rate (HR), stroke volume (SV), and power output were continuously monitored. Statistical analyses included a two-way repeated measures ANOVA and Wilcoxon signed-rank tests to assess differences in alpha and beta power spectral densities (PSDs) and the EEG/ V ˙ O2 ratio. Our results showed that during the SPV test, the beta PSD initially increased but stabilized at around 80% of the test duration, suggesting effective management of effort without further neural strain. In contrast, the IET showed a continuous increase in beta activity, indicating greater neural demand and potentially leading to an earlier onset of fatigue. Additionally, participants maintained similar cardiorespiratory parameters ( V ˙ O2, HR, SV, respiratory frequency, etc.) across both protocols, reinforcing the reliability of the RPE scale in guiding exercise intensity. These findings suggest that SPV better optimizes neural efficiency and delays fatigue compared to fixed protocols and that individuals can accurately control exercise intensity based on perceived exertion. Despite the small sample size, the results provide valuable insights into the potential benefits of self-paced exercise for improving adherence to exercise programs and optimizing performance across different populations. [ABSTRACT FROM AUTHOR]

In challenging operational environments, Lithium‐ion batteries (LIBs) inevitably experience mechanical stresses, including impacts and extrusion, which can lead to battery damage, failure, and even the occurrence of fire and explosion incidents. Consequently, it is imperative to investigate the safety performance of LIBs under mechanical loads. This study is grounded in a more realistic coupling scenario consisting of electrochemical cycling and low‐velocity impact. We systematically and experimentally uncovered the mechanical, electrochemical, and thermal responses, damage behavior, and corresponding mechanisms under various conditions. Our study demonstrates that higher impact energy results in increased structural stiffness, maximum temperature, and maximum voltage drop. Furthermore, heightened impact energy significantly influences the electrical resistance parameters within the internal resistance. We also examined the effects of State of Charge (SOC) and C‐rates. The methodology and experimental findings will offer insights for enhancing the safety design, conducting risk assessments, and enabling the cascading utilization of energy storage systems based on LIBs. [ABSTRACT FROM AUTHOR]

Li3V2(PO4)3 (LVP) is a prospective cathode material meeting the uninterrupted requirements due to the high theoretical capacity and operating voltage. Nevertheless, the electrochemical capability of pristine LVP is severely restricted under a high operating voltage. Herein, carbon decorated LVP was prepared through the process of citric acid assisted gel and subsequent heat treating. The crystalline phase, morphology, microstructure, and composition of obtained materials were examined using different methods. Transmission electron microscopy result exhibits that the crystalline LVP surface is coated with an amorphous carbon layer of about 3–5 nm thickness, and the LVP particles are connected by carbon. The electrochemical capability of LVP cathode at a cut-off voltage of 4.8 V was determined. The results exhibit the discharge capacity of carbon decorated LVP at 1 C decreases slowly from the initial 132.0 to 104.1 mA h g–1 after 200 cycles. Correspondingly, the carbon decorated LVP delivers 78.9% capacity retention, which is much larger than that of pristine LVP (46.6%), suggesting the enhanced stability. In addition, the rate and Coulombic efficiency of carbon decorated LVP are also obviously enhanced compared to the pristine LVP. The work verifies a simple modification method to ameliorate the inherent drawbacks and electrochemical properties of LVP at high voltage. [ABSTRACT FROM AUTHOR]

The Use of Heated Garments as a Warm-Up for Sprint and Submaximal Effort Cycling. JEPonline 2024;27(5):57-69. The purpose of the study was to compare physiological and biomechanical responses using passive and active warm-up techniques. Two separate cycling experiments were conducted differing in intensity: 1) maximal effort, sprint cycling; 2) Submaximal steady state cycling. The 2 experiments were completed with different groups of subjects in separate labs. The sprint subjects (Sprint: n = 7, 22.2 ± 2.6 yrs, 78.6 ± 15.0 kg, 174.4 ± 10.8 cm) completed a 6-sec sprint test and a 30-sec sprint test with peak power output, maximum torque, and maximal cadence measured. The submaximal subjects (47.5 ± 14.4 yrs, 76.4 ± 12.9 kg, 169.3 ± 9.6 cm) completed a 10-min submaximal effort at a fixed intensity with physiological variables (rate of oxygen consumption, rate of carbon dioxide expired, and heart rate) measured. Each experiment consisted of subjects completing a passive warm-up using heated trousers as well as an active warm-up. Sprint results: peak power output and maximum torque were greater pre- vs. post-passive, but not following the active warm-up during the 2nd 6-sec (P < 0.05). For the 30-sec test, neither the peak power output nor the average power was different between the passive and the active warm-up (P > 0.05). Submaximal results: none of the physiological variables were different between the warm-up conditions (P > 0.05). Overall, it was determined that the passive warm-up could be a substitute for the active warm-up for sprint and/or submaximal cycling efforts. [ABSTRACT FROM AUTHOR]

Heterogeneous elements doping in carbon materials has been an effective strategy to promote their chemical properties. In this work, fluorine atoms with strong electronegativity are doped on the surfaces of bamboo-shaped carbon nanotubes (FBCNTs) which serve as carriers for MgH 2 nanoparticles (MgH 2 @FBCNTs) to improve the reversible hydrogen storage properties. Detailed experiments indicate that MgH 2 @FBCNTs begin to release hydrogen at 197.8 °C, and can release 5.36 wt% H 2 at 275 °C within 30 min, and quickly absorb 3.48 wt% H 2 at 100 °C under hydrogen pressure of 80 bar. In addition, cycling performance is significantly enhanced in the case of fluorinated Mg-based system. The mechanism of fluorine catalysis is mainly ascribed to the formation of C-F bonds, accelerating the dissociation or combination of hydrogen atoms, offering more active sites for the de/hydrogenation and preventing the growth and agglomeration during cycling. It is also important that fraction of F is consumed and form new phases MgF 2 /MgF 2-x H x , which offers another pathway for H atoms. • Fluorinated bamboo-shaped carbon nanotubes were used as carriers for MgH 2. • MgH 2 @FBCNTs release 5.80 wt% H 2 at 250 °C(5 min) and quickly absorb 3.48 wt% H 2 at 100 °C(30 min). • Catalytic mechanism is ascribed to the formed MgF 2 and MgF 2-x H x acting as electron transfer medium resembling a "gate". [ABSTRACT FROM AUTHOR]

In the development of lithium ion batteries (LIBs) with higher energy density and safety, solid-state lithium batteries (SSLBs) have attracted widespread attention. However, even in SSLBs, when metallic lithium is used as the anode, lithium dendrites can still form during the lithium-ion deintercalation process, leading to poor cycling performance of the battery. Herein, lithium-boride (Li-B) alloy with a layered three-dimensional skeleton structure was synthesized and investigated as anode for SSLBs. Due to the stability of the special three-dimensional skeleton structure, the deintercalation of lithium ions does not cause the collapse of the material structure. Thus, compared to the metallic lithium anode, the Li-B alloy exhibits higher discharge specific capacity and better cycling performance (when using the as-prepared lithium-rich manganese-based (Li1.2Ni0.2Mn0.6O2) as the cathode material, the initial discharge capacity of the SSLBs is 209 mAh g–1, and when using LiFePO4 as the cathode material, the initial discharge capacity is 192 mAh g–1, with a capacity retention rate of 82% after 50 cycles). [ABSTRACT FROM AUTHOR]

MnCo2O4 nanoclusters were prepared using a simple and cost-effective hydrothermal method followed by calcination at 400°C for 3 h. Their structural analysis showed the high crystalline nature of the spinel MnCo2O4 with an average crystalline size of 50 nm. The Fourier-transform infrared (FTIR) spectroscopic bands at 558 and 652 cm−1 confirmed the chemical structural coordination of Mn-O and Co-O bonds in the case of the MnCo2O4 sample. The Raman vibrational bands observed at 196 cm−1, 477 cm−1, 607 cm−1, and 680 cm−1 confirmed the formation of crystalline MnCo2O4. The morphological analyses displayed the nanoclusters morphology for the MnCo2O4 and the energy dispersive spectroscopy (EDS) analysis confirmed the presence of Mn, Co, and O elements in the synthesized material. The x-ray photoelectron spectroscopy (XPS) results revealed the existence of the mixed Co2+/Co3+ and Mn3+/Mn4+ valence states in the prepared MnCo2O4 nanoclusters. The MnCo2O4 nanocluster-based electrode in 3 M KOH electrolyte revealed a better electrochemical performance, with a specific capacitance of 350 F g−1 at a scan rate of 10 mV s−1 from the cyclic voltammetry study, and exhibited a higher capacitance value of 333 F g−1 at a current density of 1 A g−1 from the galvanostatic charge–discharge (GCD) analysis. Long duration cycle stability studies revealed that the MnCo2O4 electrode exhibited high stability after 1000 GCD cycles and retained 80.5% of its initial capacitance at a current density of 5 A g−1. These results suggest that the prepared MnCo2O4 nanoclusters might be well suited to be an efficient supercapacitor electrode material. [ABSTRACT FROM AUTHOR]

Silver (Ag) is deemed a promising anode material for capacitive deionization (CDI) due to its high theoretical capacity and efficient selectivity to Cl−. However, the strong volume change during the conversion reaction significantly undermines the cycling performance of the Ag electrode. Additionally, achieving well‐dispersed Ag in the active matrix is challenging, as Ag electrodes prepared by conventional thermal reduction tend to agglomerate. Herein, the organic linker confinement strategy is proposed, applying metal–organic framework (MOF) chemistry between Ag nodes and organic ligands to construct Ag‐based MOF. The uniform dispersion of Ag at the molecular level, confined in the organic matrix, efficiently enhances the utilization of active sites, and strengthens the interfacial stability of Ag. Consequently, the Ag‐MOF for the CDI anode exhibits an excellent Cl− removal capacity of 121.52 mg g−1 at 20 mA g−1 in 500 mg L−1 NaCl solution, and a high Ag utilization rate of 60.54%. After 100 cycles, a capacity retention of 96.93% is achieved. Furthermore, the Cl− capture mechanism of Ag‐MOF is elucidated through density functional theory (DFT) calculations, ex situ XRD, ex situ Raman and XPS. This ingenious electrode design can offer valuable insights for the development of high‐performance conversion electrodes for CDI applications. [ABSTRACT FROM AUTHOR]

V2CTx MXenes have gained considerable attention in lithium ion batteries (LIBs) owing to their special two-dimensional (2D) construction with large lithium storage capability. However, engineering high-capacity V2CTx MXenes is still a great challenge due to the limited interlayer space and poor surface terminations. In view of this, alkalized and oxidized V2CTx MXenes (OA-V2C) are envisaged. SEM characterization confirms the accordion-like layered morphology of OA-V2C. The XPS technique illustrates that undergoing alkalized and oxidized treatment, V2CTX MXene replaces -F and -OH with -O groups, which are more conducive to pseudocapacitive properties as well as Na ion diffusion, providing more active sites for ion storage in OA-V2C. Accordingly, the electrochemical performance of OA-V2C as anode materials for LIBs is evaluated in this work, showing excellent performance with high reversible capacity (601 mAh g−1 at 0.2 A g−1 over 500 cycles), competitive rate performance (222.2 mAh g−1 and 152.8 mAh g−1 at 2 A g−1 and 5 A g−1), as well as durable long-term cycling property (252 mAh g−1 at 5 A g−1 undergoing 5000 cycles). It is noted that the intercalation of Na+ ions and oxidation co-modification greatly reduces F surface termination and concurrently increases interlayer spacing in OA-V2C, significantly expediting ion/electron transportation and providing an efficient way to maximize the performance of MXenes in LIBs. This innovative refinement methodology paves the way for building high-performance V2CTx MXenes anode materials in LIBs. [ABSTRACT FROM AUTHOR]

Purpose: This study examined the repeated bout effect of two resistance training bouts on cycling efficiency and performance. Methods: Ten male resistance-untrained cyclists (age 38 ± 13 years; height 180.4 ± 7.0 cm; weight 80.1 ± 10.1; kg; VO2max 51.0 ± 7.6 ml.kg−1.min−1) undertook two resistance training bouts at six-repetition maximum. Blood creatine kinase (CK), delayed-onset of muscle soreness (DOMS), counter-movement jump (CMJ), squat jump (SJ), submaximal cycling and time-trial performance were examined prior to (Tbase), 24 (T24) and 48 (T48) h post each resistance training bout. Results: There were significantly lower values for DOMS (p = 0.027) after Bout 2 than Bout 1. No differences were found between bouts for CK, CMJ, SJ and submaximal cycling performance. However, jump height (CMJ and SJ) submaximal cycling measures (ventilation and perceived exertion) were impaired at T24 and T48 compared to Tbase (p < 0.05). Net efficiency during submaximal cycling improved at Bout 2 (23.8 ± 1.2) than Bout 1 (24.3 ± 1.0%). There were no changes in cycling time-trial performance, although segmental differences in cadence were observed between bouts and time (i.e. Tbase vs T24 vs T48; p < 0.05). Conclusion: Cyclists improved their cycling efficiency from Bout 1 to Bout 2 possibly due to the repeated bout effect. However, cyclists maintained their cycling completion times during exercise-induced muscle damage (EIMD) in both resistance training bouts, possibly by altering their cycling strategies. Thus, cyclists should consider EIMD symptomatology after resistance training bouts, particularly for cycling-specific technical sessions, regardless of the repeated bout effect. [ABSTRACT FROM AUTHOR]

Layered oxide is a promising cathode material for sodium-ion batteries because of its high-capacity, high operating voltage, and simple synthesis. Cycling performance is an important criterion for evaluating the application prospects of batteries. However, facing challenges, including phase transitions, ambient stability, side reactions, and irreversible anionic oxygen activity, the cycling performance of layered oxide cathode materials still cannot meet the application requirements. Therefore, this review proposes several strategies to address these challenges. First, bulk doping is introduced from three aspects: cationic single doping, anionic single doping, and multi-ion doping. Second, homogeneous surface coating and concentration gradient modification are reviewed. In addition, methods such as mixed structure design, particle engineering, high-entropy material construction, and integrated modification are proposed. Finally, a summary and outlook provide a new horizon for developing and modifying layered oxide cathode materials. [ABSTRACT FROM AUTHOR]

This study investigates the performance and cycling fading of a solid-state fluoride-ion battery (FIB) based on the CuF2 electrode. The cathode and solid electrolyte of CuF2 composite and La0.9Ba0.1F2.9 are prepared by ballmilling. Meanwhile, the anode materials are used as Sn and Pb. All FIB cells with sandwich structures are fabricated by compressing under a pressure of 4.5 tons/cm². Electrochemical measurements of discharge/charge are performed at 423 K and under 40 μA/cm². The resultant cycling stability of the cell with the Pb anode is higher than that of the cell with the Sn anode. Concerning the cell with Pb anode, the first and tenth discharge capacities of 150 and 90 mAh/g are obtained. X-ray photoelectron analysis demonstrates that the cycling fading of the cell with the Sn (or Pb) anode may be attributed to the irreversible formation of materials (e.g., SnF4 or PbF4) during the electrochemical reaction. [ABSTRACT FROM AUTHOR]

Professional road cycling requires high endurance and power output for optimal performance. Oval chainrings, a recent innovation, aim to minimize dead spots during pedal revolutions and enhance cycling performance. This study compared the effects of circular (C-ring) and oval (Q-ring) chainrings on power output and maximum oxygen consumption (V·O2Max) during an incremental exercise test. Twenty male elite cyclists (mean age ± SD: 19.90 ± 1.86 years) participated in a randomized study. They underwent two incremental maximal tests separated by 48 hours, using both chainring types. The test began with participants pedaling with a 200-watt load in their preferred cadence. During the first six-minute period, the load was increased by 50 watts every two minutes, and then the test continued to increase by 25 watts every two minutes. The test was completed at the point where the participant was exhausted. The results indicated significant differences in favor of Q-rings for V·O2Max (p = 0.006) and power output (p = 0.014), while heart rate and cadence remained similar. High correlations were found between V·O2Max/power output and heart rate mean/max. Linear regression analysis revealed that power output accounted for 52% (Q-ring) and 64% (C-ring) of the variance in V·O2Max. Theoretical advantages of Q-rings include optimizing pedal force distribution, which may enhance mechanical performance. Previous studies have shown mixed results regarding the effects of non-circular chainrings on cycling performance, indicating methodological disparities. Overall, this study suggests that Q-rings may improve road cycling performance by increasing power output. However, further research is needed to explore their efficacy across various cycling scenarios.

Lithium metal batteries (LMBs) represent the most promising next‐generation high‐energy density batteries. The solid electrolyte interphase (SEI) film on the lithium metal anode plays a crucial role in regulating lithium deposition and improving the cycling performance of LMBs. In this review, we comprehensively present the formation process of the SEI film, while elucidating the key properties such as electronic conductivity, ionic conductivity, and mechanical performance. Furthermore, various approaches for constructing the SEI film are discussed from both electrolyte regulation and artificial coating design perspectives. Lastly, future research directions along with development recommendations are also provided. This review aims to provide possible strategies for the further improvement of SEI film in LMBs and highlight their inspiration for future research directions. [ABSTRACT FROM AUTHOR]

Using silicon/reduced graphene oxide (Si/rGO) composites as lithium-ion battery (LIB) anodes can effectively buffer the volumetric expansion and shrinkage of Si. Herein, we designed and prepared Si/rGO-b with a sandwiched structure, formed by a duple combination of ammonia-modified silicon (m-Si) nanoparticles (NP) with graphene oxide (GO). In the first composite process of m-Si and GO, a core–shell structure of primal Si/rGO-b (p-Si/rGO-b) was formed. The amino groups on the m-Si surface can not only hybridize with the GO surface to fix the Si particles, but also form covalent chemical bonds with the remaining carboxyl groups of rGO to enhance the stability of the composite. During the electrochemical reaction, the oxygen on the m-Si surface reacts with lithium ions (Li+) to form Li2O, which is a component of the solid–electrolyte interphase (SEI) and is beneficial to buffering the volume expansion of Si. Then, the p-Si/rGO-b recombines with GO again to finally form a sandwiched structure of Si/rGO-b. Covalent chemical bonds are formed between the rGO layers to tightly fix the p-Si/rGO-b, and the conductive network formed by the reintroduced rGO improves the conductivity of the Si/rGO-b composite. When used as an electrode, the Si/rGO-b composite exhibits excellent cycling performance (operated stably for more than 800 cycles at a high-capacity retention rate of 82.4%) and a superior rate capability (300 mA h/g at 5 A/g). After cycling, tiny cracks formed in some areas of the electrode surface, with an expansion rate of only 27.4%. The duple combination of rGO and the unique sandwiched structure presented here demonstrate great effectiveness in improving the electrochemical performance of alloy-type anodes. [ABSTRACT FROM AUTHOR]

The study aimed to investigate the effects of sodium bicarbonate (NaHCO3) intake with divergent verbal and visual information on constant load cycling time-to-task failure, conducted within the severe intensity domain. Fifteen recreational cyclists participated in a randomized double-blind, crossover study, ingesting NaHCO3 or placebo (i.e., dextrose), but with divergent information about its likely influence (i.e., likely to induce ergogenic, inert, or harmful effects). Performance was evaluated using constant load cycling time to task failure trial at 115% of peak power output estimated during a ramp incremental exercise test. Data on blood lactate, blood acid–base balance, muscle electrical activity (EMG) through electromyography signal, and the twitch interpolation technique to assess neuromuscular indices were collected. Despite reduced peak force in the isometric maximal voluntary contraction and post-effort peripheral fatigue in all conditions (P < 0.001), neither time to task failure, EMG nor, blood acid–base balance differed between conditions (P > 0.05). Evaluation of effect sizes of all conditions suggested that informing participants that the supplement would be likely to have a positive effect (NaHCO3/Ergogenic: 0.46; 0.15–0.74; Dextrose/Ergogenic: 0.45; 0.04–0.88) resulted in improved performance compared to control. Thus, NaHCO3 ingestion consistently induced alkalosis, indicating that the physiological conditions to improve performance were present. Despite this, NaHCO3 ingestion did not influence performance or indicators of neuromuscular fatigue. In contrast, effect size estimates indicate that participants performed better when informed that they were ingesting an ergogenic supplement. These findings suggest that the apparently ergogenic effect of NaHCO3 may be due, at least in part, to a placebo effect. [ABSTRACT FROM AUTHOR]

Incorporating a selenium (Se) positive electrode into aluminum (Al)-ion batteries is an effective strategy for improving the overall battery performance. However, the cycling stability of Se positive electrodes has challenges due to the dissolution of intermediate reaction products. In this work, we aim to harness the advantages of Se while reducing its limitations by preparing a core–shell mesoporous carbon hollow sphere with a titanium nitride (C@TiN) host to load 63.9wt% Se as the positive electrode material for Al–Se batteries. Using the physical and chemical confinement offered by the hollow mesoporous carbon and TiN, the obtained core–shell mesoporous carbon hollow spheres coated with Se (Se@C@TiN) display superior utilization of the active material and remarkable cycling stability. As a result, Al–Se batteries equipped with the as-prepared Se@C@TiN composite positive electrodes show an initial discharge specific capacity of 377 mAh·g−1 at a current density of 1000 mA·g−1 while maintaining a discharge specific capacity of 86.0 mAh·g−1 over 200 cycles. This improved cycling performance is ascribed to the high electrical conductivity of the core–shell mesoporous carbon hollow spheres and the unique three-dimensional hierarchical architecture of Se@C@TiN. [ABSTRACT FROM AUTHOR]

Energy shortage hinders the rapid development of today's society, and the emergence of electronic travel equipment alleviates this phenomenon to a certain extent. The batteries are the energy storage part of electric equipment. Metal-organic frameworks (MOFs) are a fresh sort of porous crystal materials with controllable structure, large specific surface area, and adjustable pore size. MOFs are good electrode materials, which are used to make a variety of friendly environment, long cycling life and superior energy density of new batteries. Furthermore, MOFs are also used in separators and electrolytes, which have a lot of application space in batteries. In this review, the up-to-date research advance of MOF materials in various kinds of batteries (lithium-ion batteries, lithium oxygen batteries, lithium sulfur batteries, zinc-ion batteries, potassium-ion batteries, etc.) is reviewed. Moreover, concisely introduced several conventional synthesis approaches of MOFs. Finally, Perspectives and directions on the future improvement of MOF in energy storage devices are proposed for meeting the requirement of practical applications. [ABSTRACT FROM AUTHOR]

The implementation of a functional separator represents a highly encouraging approach to mitigating polysulfide shuttling in lithium–sulfur (Li–S). In this study, a two-dimensional (2D) 1,3,5-triformylphloroglucinol (Tp)-p-phenylenediamine (Pa) covalent organic framework/reduced graphene oxide (rGO) functional layer was introduced to enhance the performance of the commercial separator in Li–S batteries. The resulting 2D TpPa@rGO modified separators exhibit significantly improved electronic and ionic conductivity when compared to the unmodified separator, effectively mitigating lithium polysulfide shuttling and enhancing sulfur cathode utilization. It is indicated that a heterostructured composite of a nitrogen-group-containing COF and an electronic conductive addictive is an effective modification to the separator. Consequently, the modified cell demonstrated a minimal degradation rate of only 0.12% per cycle over 350 cycles at 0.5 C. [ABSTRACT FROM AUTHOR]

Featured Application: The findings of the present study may inform decision-making for track cycling coaches and practitioners in planning talent identification and development strategies. Moreover, the results presented raise concerns and underscore the importance of distinguishing between primary and secondary factors when aiming to support future talent in track cycling. Track cycling entails a challenging progression from the youth categories to elite competition. Hence, this study aimed to investigate the importance of early performance and various publicly available performance indicators in predicting the success of male and female cyclists across different track disciplines. Additionally, the study enriches the findings by incorporating interviews with international-level coaches and athletes. A retrospective analysis of data from UCI track cycling databases was conducted, supplemented by interviews with international-level coaches and athletes. The success rate for highly ranked junior track cyclists was found to be less than 20%, with a majority of these athletes specializing in sprint events, regardless of gender. The study indicated that the UCI ranking and points earned during the season were not reliable indicators for distinguishing future success (p < 0.05). From the interviews, we identified three main themes: (1) trends in career success from the youth to elite categories, (2) performance markers as predictors of future success, and (3) the challenges and time involved in reaching elite categories. Junior category performance alone may not be the sole indicator of future success in track cycling. However, integrating performance analyses with practitioners and athletes' perspectives enables a deeper understanding of the results and the developmental context. [ABSTRACT FROM AUTHOR]

Professional road cycling requires high endurance and power output for optimal performance. Oval chainrings, a recent innovation, aim to minimize dead spots during pedal revolutions and enhance cycling performance. This study compared the effects of circular (C-ring) and oval (Q-ring) chainrings on power output and maximum oxygen consumption (V̇ O2Max) during an incremental exercise test. Twenty male elite cyclists (mean age ± SD: 19.90 ± 1.86 years) participated in a randomized study. They underwent two incremental maximal tests separated by 48 hours, using both chainring types. The test began with participants pedaling with a 200-watt load in their preferred cadence. During the first sixminute period, the load was increased by 50 watts every two minutes, and then the test continued to increase by 25 watts every two minutes. The test was completed at the point where the participant was exhausted. The results indicated significant differences in favor of Q-rings for V̇ O2Max (p = 0.006) and power output (p = 0.014), while heart rate and cadence remained similar. High correlations were found between V̇ O2Max/power output and heart rate mean/max. Linear regression analysis revealed that power output accounted for 52% (Q-ring) and 64% (C-ring) of the variance in V̇ O2Max. Theoretical advantages of Q-rings include optimizing pedal force distribution, which may enhance mechanical performance. Previous studies have shown mixed results regarding the effects of non-circular chainrings on cycling performance, indicating methodological disparities. Overall, this study suggests that Q-rings may improve road cycling performance by increasing power output. However, further research is needed to explore their efficacy across various cycling scenarios. [ABSTRACT FROM AUTHOR]

Abstract Silver (Ag) is deemed a promising anode material for capacitive deionization (CDI) due to its high theoretical capacity and efficient selectivity to Cl−. However, the strong volume change during the conversion reaction significantly undermines the cycling performance of the Ag electrode. Additionally, achieving well‐dispersed Ag in the active matrix is challenging, as Ag electrodes prepared by conventional thermal reduction tend to agglomerate. Herein, the organic linker confinement strategy is proposed, applying metal–organic framework (MOF) chemistry between Ag nodes and organic ligands to construct Ag‐based MOF. The uniform dispersion of Ag at the molecular level, confined in the organic matrix, efficiently enhances the utilization of active sites, and strengthens the interfacial stability of Ag. Consequently, the Ag‐MOF for the CDI anode exhibits an excellent Cl− removal capacity of 121.52 mg g−1 at 20 mA g−1 in 500 mg L−1 NaCl solution, and a high Ag utilization rate of 60.54%. After 100 cycles, a capacity retention of 96.93% is achieved. Furthermore, the Cl− capture mechanism of Ag‐MOF is elucidated through density functional theory (DFT) calculations, ex situ XRD, ex situ Raman and XPS. This ingenious electrode design can offer valuable insights for the development of high‐performance conversion electrodes for CDI applications.

This systematic review analyzed whether carbohydrate source (food vs. supplement) influenced performance and gastrointestinal (GI) symptoms during endurance exercise. Medline, SPORTDiscus, and citations were searched from inception to July 2021. Inclusion criteria were healthy, active males and females aged >18 years, investigating endurance performance, and GI symptoms after ingestion of carbohydrate from a food or supplement, <60 min before or during endurance exercise. The van Rosendale scale was used to determine risk of bias, with seven studies having low risk of bias. A total of 151 participants from 15 studies were included in the review. Three studies provided 0.6–1 g carbohydrate/kg body mass during 5–45 min precycling exercise (duration 60–70 min) while 12 studies provided 24–80 g/hr carbohydrate during exercise (60–330 min). Except one study that suggested a likely harmful effect (magnitude-based inferences) of a bar compared to a gel consumed during exercise on cycling performance, there were no differences in running (n = 1) or cycling (n = 13) performance/capacity between food and supplemental sources. Greater GI symptoms were reported with food compared with supplemental sources. Highly heterogenous study designs for carbohydrate dose and timing, as well as exercise protocol and duration, make it difficult to compare findings between studies. A further limitation results from only one study assessing running performance. Food choices of carbohydrate consumed immediately before and during endurance exercise result in similar exercise performance/capacity responses to supplemental carbohydrate sources, but may slightly increase GI symptoms in some athletes, particularly with exercise >2 hr. [ABSTRACT FROM AUTHOR]

Purpose: This study tested the hypothesis of whether ischemic exercise preconditioning (IPC-Ex) elicits a better intense endurance exercise performance than traditional ischemic preconditioning at rest (IPC-rest) and a SHAM procedure. Methods: Twelve men (average V ˙ O 2 max ∼61 mL·kg−1·min−1) performed 3 trials on separate days, each consisting of either IPC-Ex (3 × 2-min cycling at ∼40 W with a bilateral-leg cuff pressure of ∼180 mm Hg), IPC-rest (4 × 5-min supine rest at 220 mm Hg), or SHAM (4 × 5-min supine rest at <10 mm Hg) followed by a standardized warm-up and a 4-minute maximal cycling performance test. Power output, blood lactate, potassium, pH, rating of perceived exertion, oxygen uptake, and gross efficiency were assessed. Results: Mean power during the performance test was higher in IPC-Ex versus IPC-rest (+4%; P =.002; 95% CI, +5 to 18 W). No difference was found between IPC-rest and SHAM (−2%; P =.10; 95% CI, −12 to 1 W) or between IPC-Ex and SHAM (+2%; P =.09; 95% CI, −1 to 13 W). The rating of perceived exertion increased following the IPC-procedure in IPC-Ex versus IPC-rest and SHAM (P <.001). During warm-up, IPC-Ex elevated blood pH versus IPC-rest and SHAM (P ≤.027), with no trial differences for blood potassium (P >.09) or cycling efficiency (P ≥.24). Eight subjects anticipated IPC-Ex to be best for their performance. Four subjects favored SHAM. Conclusions: Performance in a 4-minute maximal test was better following IPC-Ex than IPC-rest and tended to be better than SHAM. The IPC procedures did not affect blood potassium, while pH was transiently elevated only by IPC-Ex. The performance-enhancing effect of IPC-Ex versus IPC-rest may be attributed to a placebo effect, improved pH regulation, and/or a change in the perception of effort. [ABSTRACT FROM AUTHOR]

Herein, we examine the human exercise response following cannabis inhalation, taking into consideration varied cannabinoid concentrations and different inhalation methods. A semirandomized crossover study design was used, with measures of perceived exertion and physiological responses to submaximal and maximal exercise. Participants (n = 14, 9 males 5 females) completed exercise after 1) smoking D-9-tetrahydrocannabinol (THC)-predominant cannabis (S-THC), 2) inhaling aerosol (vaporizing) from THC-predominant cannabis (V-THC), 3) inhaling aerosol from cannabidiol (CBD)-predominant cannabis (V-CBD), or 4) under control conditions. All exercise was performed on a cycle ergometer, with submaximal testing performed at 100 W followed by an evaluation of maximal exercise performance using an all-out 20-min time trial. Metabolism was characterized via the analysis of expired gases while subjective ratings of perceived exertion (RPE) were reported. During submaximal cycling, heart rate was higher during S-THC and V-THC compared with both control and V-CBD (all P < 0.02). During maximal exercise, V_ E was lower in V-THC compared with control, S-THC, and V-CBD (all P < 0.03), as was S-THC compared with control (P < 0.05). Both V O2 and RPE were similar between conditions during maximal exercise (both P > 0.1). Mean power output during the 20-min time trial was significantly lower in the S-THC and V-THC conditions compared with both control and V-CBD (all P < 0.04). Cannabis containing THC alters the physiological response to maximal and submaximal exercise, largely independent of the inhalation method. THC-containing cannabis negatively impacts vigorous exercise performance during a sustained 20-min effort, likely due to physiological and psychotropic effects. Inhalation of cannabis devoid of THC and primarily containing CBD has little physiological effect on the exercise response or performance. [ABSTRACT FROM AUTHOR]

Copyright of Chemistry & Industry of Forest Products is the property of Chemistry & Industry of Forest Products Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The wet carbonation process of steel slag (SS) is envisaged to be an effective way to sequestrate CO2 and improve the properties of SS as a supplementary cementitious material. However, the carbonation process still struggles with having a low carbonation efficiency. This paper studied the effect of glycine on the accelerated carbonation of SS. The phase composition change of carbonated SS was analyzed via XRD, FT-IR, and TG–DTG. The carbonation process of SS is facilitated by the assistance of glycine, with which the carbonation degree is increased. After 60 min of carbonation, SS with glycine obtained a CO2 sequestration rate of 9.42%. Meanwhile, the carbonation reaction could decrease the content of free calcium oxide in SS. This significantly improves the soundness of SS–cement cementitious material, and the compressive strength of cementitious materials that contain carbonated SS with glycine is improved. Additionally, the cycling performance of glycine in the successive wet carbonation process of SS was investigated. Multicycle experiments via solvent recovery demonstrated that although the promotion effect of glycine was reduced after each cycle, compared with the SS–water system, the carbonation process could still be facilitated, demonstrating that successive wet carbonation via solvent recovery has considerable potential. Herein, we provide a new idea to facilitate the wet carbonation process of SS and improve the properties of SS–cement cementitious material. [ABSTRACT FROM AUTHOR]

Purpose: Polluted environments can adversely affect lung function and exercise performance. Evidence suggests that some nutrient supplements may offset pollution's detrimental effects. This study examined the effect of polyphenol supplementation on lung function and exercise performance in an ozone-polluted environment. Methods: Ten male cyclists (mean ± SD: age, 43.8 ± 12.4 years; height, 177.8 ± 7.1 cm; weight, 76.03 ± 7.88 kg; VO2max 4.12 ± 0.72 L min−1) initially completed a baseline maximal incremental test and maximal effort 4 km time trial in ambient air. Thereafter cyclists completed two trials in an ozone-polluted environment (0.25 ppm) following seven days of supplementation with either polyphenol (PB) or placebo (PL). Experimental trials consisted of a three-stage submaximal test (50%, 60% and 70% incremental peak power) followed by a 4 km time trial. Lung function was measured pre- and post-exercise via spirometry and adverse respiratory symptoms with a Likert scale. Results: Ozone exposure significantly reduced (p < 0.05) lung function relative to ambient air. There were no significant differences (p > 0.05) in measured variables across the three submaximal intensities. There was a small (d = 0.31) non-significant difference (p = 0.09) in 4 km performance in PB (406.43 ± 50.29 s) vs. PL (426.20 ± 75.06 s). Oxygen consumption during the time trial was greater in PB (3.49 ± 0.71 L min−1) vs PL (3.32 ± 0.71 L min−1, p = 0.01, d = 0.24). Cough severity (SOC) was lower (p = 0.03) with PB relative to PL. Conclusion: PB supplementation may provide small benefits to performance and reduce cough symptoms during high-intensity exercise in ozone-polluted environments. [ABSTRACT FROM AUTHOR]

Biomass-derived porous carbon displays a great potential for lithium–selenium (Li–Se) batteries owing to its green resource and inherent structural advantages, which can effectively restrict the shuttle effect of Se cathode. Peanut meal, by-product of the extraction of peanut oil, is a promising precursor for N-doped porous carbon. However, peanut meal is difficult to be activated in solution due to its high hydrophobicity. Thus, non-reports have been available for peanut meal-derived porous carbon used as Li–Se battery cathode host. In this work, we have innovatively proposed a very simple method of activating peanut meal by directly physically grinding the activator with the peanut meal and then annealing it to convert it into nitrogen-doped three-dimensional porous carbon (N-PC) with rich nanoscale pore size structures, which is then used as the Se host for Li–Se batteries. The N-PC shows a high specific surface area of 938.872 m2 g−1. The Se/N-PC composite cathode delivers a specific capacity of 461.4 mA h g−1 for 250 cycles at 0.2 C, corresponding to a high-capacity retention of 97.2%. Moreover, the Se/N-PC composite maintains a high capacity over 340.1 mA h g−1 after 1,000 cycles at a high current density of 2 C. Our work effectively resolves the hydrophobic biomass activation problem and manufactures abundant and low-cost Se host for Li–Se batteries.

Purpose: To investigate the effects of including repeated sprints in a weekly low-intensity (LIT) session during a 3-week transition period on cycling performance 6 weeks into the subsequent preparatory period (PREP) in elite cyclists. Methods: Eleven elite male cyclists (age = 22.0 [3.8] y, body mass = 73.0 [5.8] kg, height = 186 [7] cm, maximal oxygen uptake [VO2max] = 5469 [384] mL·min−1) reduced their training load by 64% and performed only LIT sessions (CON, n = 6) or included 3 sets of 3 × 30-second maximal sprints in a weekly LIT session (SPR, n = 5) during a 3-week transition period. There was no difference in the reduction in training load during the transition period between groups. Physiological and performance measures were compared between the end of the competitive period and 6 weeks into the PREP. Results: SPR demonstrated a 7.3% (7.2%) improvement in mean power output during a 20-minute all-out test at PREP, which was greater than CON (−1.3% [4.6%]) (P =.048). SPR had a corresponding 7.0% (3.6%) improvement in average VO2 during the 20-minute all-out test, which was larger than the 0.7% (6.0%) change in CON (P =.042). No change in VO2max, gross efficiency, or power output at blood lactate concentration of 4 mmol·L−1 from competitive period to PREP occurred in either group. Conclusion: Including sprints in a weekly LIT session during the transition period of elite cyclists provided a performance advantage 6 weeks into the subsequent PREP, which coincided with a higher performance VO2. [ABSTRACT FROM AUTHOR]

Purpose: Cyclists may increase exercise intensity by prolonging exercise duration and/or shortening the recovery period during self-paced interval training, which could impact the time spent near V ˙ O 2 max. Thus, the main objective of this study was to compare the time spent near V ˙ O 2 max during 4 different self-paced interval training sessions. Methods: After an incremental test, 11 cyclists (mean [SD]: age = 34.4 [6.2] y; V ˙ O 2 max = 55.7 [ 7.4 ] mL · kg − 1 · min − 1 ) performed in a randomized order 4 self-paced interval training sessions characterized by a work–recovery ratio of 4:1 or 2:1. Sessions comprised 4 repetitions of 4 minutes of cycling with 1 minute (4/1) or 2 minutes (4/2) of active recovery or 8 minutes of cycling with 2 minutes (8/2) or 4 minutes (8/4) of active recovery. Time spent at 90% to 94% (t 90 V ˙ O 2 max), ≥95% (t 95 V ˙ O 2 max), and 90% to 100% V ˙ O 2 max (t V ˙ O 2 max) was analyzed in absolute terms and relative to the total work duration. Power output, heart rate, blood lactate, and rating of perceived exertion were compared. Results: The 8/4 session provided higher absolute t V ˙ O 2 max and t 95 V ˙ O 2 max than 8/2 (P =.015 and.029) and 4/1 (P =.002 and.047). The 4/2 protocol elicited higher relative t V ˙ O 2 max (47.7% [26.9%]) and t 95 V ˙ O 2 max (23.5% [22.7%]) than 4/1 (P =.015 and.028) and 8/2 (P <.01). Session 4/2 (275 [23] W) elicited greater mean power output (P <.01) than 4/1 (261 [27] W), 8/4 (250 [25] W), and 8/2 (234 [23] W). Conclusions: Self-paced interval training composed of 4-minute and 8-minute work periods efficiently elicit t V ˙ O 2 max , but protocols with a work–recovery ratio of 2:1 (ie, 4/2 and 8/4) could be prioritized to maximize t V ˙ O 2 max. [ABSTRACT FROM AUTHOR]

Purpose: Women's professional cycling has grown in popularity, and this increase is also apparent in Brazil, which has increased its female cycling calendar in recent years. The aim of this observational study was to (1) determine training and competition loads of a top-level Brazilian female cycling team, (2) evaluate nutrition and clinical health, and (3) measure whether exercise capacity changed throughout the season. Methods: Training and competition data were collected over the season using global positioning system monitors, while laboratory-based physiological and performance measures (incremental cycling test, 30-s Wingate, 4-km time trial) and clinical and nutritional analyses were performed at time points throughout the season. Results: Total distance covered over the year was 11,124 (2895) km (7382–14,698 km). Endurance capacity was reduced over the season (P =.005) but not anaerobic power (all P >.05). Nutrition and stress markers remained largely unchanged throughout the season, although there were some individual fluctuations in some measures, and testosterone concentration was low for some. Median estimated energy availability ranged between 32.3 and 56.8 kcal·kgLBM−1·d−1 during training and 26.4 and 53.8 kcal·kgLBM−1·d−1 during competition. Percentage of training spent in optimal estimated energy availability was generally low, with 3 athletes spending <35% within the optimal intake. Conclusions: Substantial training and competition loads of the monitored professional Brazilian female cyclists may have reduced exercise capacity toward the end of the season, indicative of a grueling yearlong schedule. Several athletes may have had suboptimal energy availability during the season, potentially affecting testosterone concentration. These data demonstrate the difficulties in maintaining optimal nutrition, health, and performance throughout a season in professional female cycling and highlight the need for quality sport-science support for this type of top-level athlete. [ABSTRACT FROM AUTHOR]

Practical applications of Li-metal anodes are limited by dendrite formation, Li loss, and poor reaction, resulting in a low Coulombic efficiency. In this study, we investigated the effects of island-shaped Ag atoms on the electrochemical behavior of Li-metal anodes. A Ag–Cu film was co-deposited through sputtering and subsequent annealing to anchor the Ag atoms with an island shape on a Cu substrate. The Ag target was co-sputtered with Cu with controlled atomic ratios in the Ag–Cu alloy. The sputtering thickness was set to 100 nm, and various annealing conditions were applied. The embedded island-shaped Ag atoms provided effective nucleation sites for Li deposition during the electrochemical nucleation of Li, increasing the nucleation density and spatial uniformity while decreasing the nucleation size and potential. Compact dendrite-free high-density Li deposition was achieved by annealing the Ag–Cu current collector (CC) at 600 °C. Under repetitive Li plating and stripping for 110 cycles at a current density of 0.5 mAcm−2 and capacity of 1 mAhcm−2, a high Coulombic efficiency of 98.5% was achieved. Conversely, the bare Cu CC had a life of up to 67 cycles under the same test conditions. [ABSTRACT FROM AUTHOR]

Numerous studies have been conducted in an attempt to discover cooling strategies that can be effective in improving exercise performance. However, the mechanism by which neck cooling relieves exercise-induced physiological stress and the optimal cooling temperature are unclear. This study aimed to investigate the effects of neck cooling at different temperatures during high-intensity cycling on body temperature, physiological variables, oxidant/antioxidant status, heat shock protein (HSP) 70 levels, and exercise performance in adolescent athletes. Seven well-trained male adolescent cyclists (age, 17.00 ± 0.76 years; athletic career, 3.86 ± 0.90 years) participated in three exercise trials involving three cooling regimens: control (CON), low-temperature (7 °C) neck cooling (LNC), and mixed-temperature (14 + 20 °C) neck cooling (MNC). The experimental condition used a cross-over design to minimize adaption to the repetitive cycling trials. Cycling consisted of a 20 km warm-up session and a two 2 km race session. Neck cooling at different temperatures was administered for 20 min during each rest period: after the warm-up, after the first 2 km race, and after the second 2 km race. Blood samples were taken to assess serum malondialdehyde (MDA), superoxide dismutase (SOD), and HSP70 levels. In addition, tympanic temperature (Tty), thermal sensation (TS), heart rate (HR), and the saturation of percutaneous oxygen (SpO2) were measured before, immediately after, and 24 h after exercise. As a measure of cycling performance, the race record and speed were measured in the first and second 2 km races. In all trials, Tty, TS, HR, MDA, SOD, and HSP70 levels significantly increased (p < 0.05), and SpO2 levels significantly decreased (p < 0.05). TS significantly decreased 24 h after exercise compared to that immediately after exercise in the LNC and MNC trials (p < 0.05). Serum HSP70 levels were significantly higher 24 h after exercise (0.87 ± 0.10 ng/mL) than immediately after exercise (0.79 ± 0.04 ng/mL) in the CON trial (p < 0.05). Twenty-four hours after exercise, the CON (0.87 ± 0.10 ng/mL) trial showed significantly higher serum HSP70 levels than the LNC (0.73 ± 0.01 ng/mL) trial (p < 0.05). There was no significant difference in cycling race record or speed between the trials (p > 0.05). Our findings suggest that neck cooling can induce a positive effect on thermal perception during recovery after cycling and that neck cooling at a relatively low temperature may be more effective in reducing exercise-induced HSP70 expression. [ABSTRACT FROM AUTHOR]

The practical application of lithium‐rich layered oxides is prohibited by the drawbacks such as severe capacity and voltage degradation resulting from unstable oxygen redox environment and the accompanied irreversible oxygen release. Herein, a facile and effective strategy is proposed to regulate the oxygen redox chemistry via foreign Fe doping and its induced intrinsic transition metal (TM) doping as well as the in situ constructed spinel surface layer. The Fe doping, together with the induced intrinsic TM dual doping, can stabilize the lattice oxygen in the bulk due to the formed stronger FeO bond, and restrain the irreversible TM migration and then the undesirable phase transformation. More importantly, thermodynamical energy barrier of oxygen activation is dramatically decreased by the O 2p–Fe 3d charge‐transfer, allowing stable oxygen redox activity. And the pre‐constructed spinel layer can effectively stabilize the surface lattice oxygen and suppress harmful interfacial side‐reactions. Such a simple optimizing method make the modified cathode exhibit a high specific capacity of 298 mAh g−1 at 0.2 C, outstanding cycling stability with a superior capacity and voltage retentions of 92.5% and 90.8%, respectively, after 400 cycles at 1 C. This study provides a new direction for developing advanced Li‐ion batteries. [ABSTRACT FROM AUTHOR]

Using silicon/reduced graphene oxide (Si/rGO) composites as lithium-ion battery (LIB) anodes can effectively buffer the volumetric expansion and shrinkage of Si. Herein, we designed and prepared Si/rGO-b with a sandwiched structure, formed by a duple combination of ammonia-modified silicon (m-Si) nanoparticles (NP) with graphene oxide (GO). In the first composite process of m-Si and GO, a core–shell structure of primal Si/rGO-b (p-Si/rGO-b) was formed. The amino groups on the m-Si surface can not only hybridize with the GO surface to fix the Si particles, but also form covalent chemical bonds with the remaining carboxyl groups of rGO to enhance the stability of the composite. During the electrochemical reaction, the oxygen on the m-Si surface reacts with lithium ions (Li+) to form Li2O, which is a component of the solid–electrolyte interphase (SEI) and is beneficial to buffering the volume expansion of Si. Then, the p-Si/rGO-b recombines with GO again to finally form a sandwiched structure of Si/rGO-b. Covalent chemical bonds are formed between the rGO layers to tightly fix the p-Si/rGO-b, and the conductive network formed by the reintroduced rGO improves the conductivity of the Si/rGO-b composite. When used as an electrode, the Si/rGO-b composite exhibits excellent cycling performance (operated stably for more than 800 cycles at a high-capacity retention rate of 82.4%) and a superior rate capability (300 mA h/g at 5 A/g). After cycling, tiny cracks formed in some areas of the electrode surface, with an expansion rate of only 27.4%. The duple combination of rGO and the unique sandwiched structure presented here demonstrate great effectiveness in improving the electrochemical performance of alloy-type anodes.

Track cycling entails a challenging progression from the youth categories to elite competition. Hence, this study aimed to investigate the importance of early performance and various publicly available performance indicators in predicting the success of male and female cyclists across different track disciplines. Additionally, the study enriches the findings by incorporating interviews with international-level coaches and athletes. A retrospective analysis of data from UCI track cycling databases was conducted, supplemented by interviews with international-level coaches and athletes. The success rate for highly ranked junior track cyclists was found to be less than 20%, with a majority of these athletes specializing in sprint events, regardless of gender. The study indicated that the UCI ranking and points earned during the season were not reliable indicators for distinguishing future success (p < 0.05). From the interviews, we identified three main themes: (1) trends in career success from the youth to elite categories, (2) performance markers as predictors of future success, and (3) the challenges and time involved in reaching elite categories. Junior category performance alone may not be the sole indicator of future success in track cycling. However, integrating performance analyses with practitioners and athletes’ perspectives enables a deeper understanding of the results and the developmental context.

Purpose: Carbohydrate (CHO) intake periodization via the sleep low train low (SL‐TL) diet–exercise model increases fat oxidation during exercise and may enhance endurance‐training adaptation and performance. Conversely, training under environmental heat stress increases CHO oxidation, but the potential of combined SL‐TL and heat stress to enhance metabolic and performance outcomes is unknown. Methods: Twenty‐three endurance‐trained males were randomly assigned to either control (n = 7, CON), SL‐TL (n = 8, SLTemp) or SL‐TL + heat stress (n = 8, SLHeat) groups and prescribed identical 2‐week cycling training interventions. CON and SLTemp completed all sessions at 20°C, but SLHeat at 35°C. All groups consumed matched CHO intake (6 g·kg−1·day−1) but timed differently to promote low CHO availability overnight and during morning exercise in both SL groups. Submaximal substrate utilization was assessed (at 20°C), and 30‐min performance tests (at 20 and 35°C) were performed Pre‐, Post‐, and 1‐week post‐intervention (Post+1). Results: SLTemp improved fat oxidation rates at 60% MAP (~66% VO2peak) at Post+1 compared with CON (p < 0.01). Compared with SLTemp, fat oxidation rates were significantly lower in SLHeat at Post (p = 0.02) and Post+1 (p < 0.05). Compared with CON, performance was improved at Post in SLTemp in temperate conditions. Performance was not different between any groups or time points in hot conditions. Conclusion: SL‐TL enhanced metabolic adaptation and performance compared with CON and combined SL‐TL and heat stress. Additional environmental heat stress may impair positive adaptations associated with SL‐TL. [ABSTRACT FROM AUTHOR]

Copyright of Fire Safety Science is the property of Fire Safety Science Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study investigates the use of lanthanide elements to modify a layered oxide cathode through solid-state calcination. Based on the findings, the modified cathodes demonstrated enhanced electrochemical performance, as lanthanide modification played dual roles in doping and coating. Some lanthanide ions entered the cathode lattice, expanding Li+ diffusion channels and stabilizing the crystal structure, while others formed a coating layer to prevent direct contact with the electrolyte and suppress undesirable side reactions. The Eu-modified cathode showed superior initial Coulombic efficiency, capacity retention, and rate ability, which can be attributed to the low dissociation energy that accelerated Eu ion entry into the cathode lattice, improving its structural stability. The Eu-modified LNCM increased Coulombic efficiency from 81.9 to 88.9%. More importantly, the data show that the modified electrode has better magnification performance and it is more stable after several cycles. This research provides new insights into the use of lanthanide modification to improve the performance of oxide cathodes, which could potentially be applied to other battery systems. [ABSTRACT FROM AUTHOR]

The high energy density, low cost, and low toxicity of LiNi0.8Co0.1Mn0.1O2 (NCM811) cathodes has led to their large‐scale mass production. However, the poor interfacial stability between NCM811 and organic electrolytes impairs the long‐cycle performance of lithium ions batteries. In this study, carbonized polymer dots (CPDs) are successfully introduced onto the surface of NCM811 (NCM811@CPDs) via a simple physical mixing process. CPDs with rich surface oxygen functional groups form strong covalent bonds with transition metal (TM) ions at the NCM811 surface, distinctly restraining surface structure degradation, and transition metal ion dissolution. Furthermore, CPDs facilitate the formation of a compact and steady cathode electrolyte interface (CEI) layer during electrochemical cycling. As a result, the NCM811@1 wt% CPDs exhibit enhanced cycling performance with a capacity retention of 89.77% after 100 cycles at 0.5 C compared to 55.39% of the bare NCM811. This facile and effective surface decoration strategy provides valuable guidance for improving the stability and cycling performance of Ni‐rich cathodes. [ABSTRACT FROM AUTHOR]

Li3V2(PO4)3 (LVP) is one of the candidates for high-energy-density cathode materials matching lithium metal batteries due to its high operating voltage and theoretical capacity. However, the inevitable side reactions of LVP with a traditional liquid-state electrolyte under high voltage, as well as the uncontrollable growth of lithium dendrites, worsen the cycling performance. Herein, a hybrid solid-state electrolyte is prepared by the confinement of a lithium-containing ionic liquid with a mesoporous SiO2 scaffold, and used for a LVP-cathode-based lithium metal battery. The solid-state electrolyte not only exhibits a high ionic conductivity of 3.14 × 10−4 S cm−1 at 30 °C and a wide electrochemical window of about 5 V, but also has good compatibility with the LVP cathode material. Moreover, the cell paired with a solid-state electrolyte exhibits good reversibility and can realize a stable operation at a voltage of up to 4.8 V, and the discharge capacity is well-maintained after 100 cycles, which demonstrates excellent capacity retention. As a contrast, the cell paired with a conventional liquid-state electrolyte shows only an 87.6% discharge capacity retention after 100 cycles. In addition, the effectiveness of a hybrid solid-state electrolyte in suppressing dendritic lithium is demonstrated. The work presents a possible choice for the use of a hybrid solid-state electrolyte compatible with high-performance cathode materials in lithium metal batteries. [ABSTRACT FROM AUTHOR]