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The completion of exercise in different body positions can impact the function of various components of the oxygen delivery pathway; however, the effect of the haemodynamic conditions induced by a semi‐upright body position on the integrative physiological response to exercise is poorly understood. The purpose of this study was to explore the effect of a semi‐upright body position on cardiac output (CO), vastus lateralis oxygen saturation (SmO2${{S}_{{\mathrm{m}}{{{\mathrm{O}}}_2}}}$), oxygen consumption (V̇O2${{\dot{V}}_{{{{\mathrm{O}}}_2}}}$) and ratings of perceived exertion (Borg RPE) during submaximal cycling. Twenty healthy individuals (22 ± 3 years, 50% female) each completed alternating 5‐min bouts of submaximal upright and semi‐upright (40° incline) cycling at 50 and 100 W. CO, SmO2${{S}_{{\mathrm{m}}{{{\mathrm{O}}}_2}}}$, V̇O2${{\dot{V}}_{{{{\mathrm{O}}}_2}}}$ and RPE were assessed at rest and at each exercise intensity during steady state. There was a main effect of intensity on the increase in CO, SmO2${{S}_{{\mathrm{m}}{{{\mathrm{O}}}_2}}}$, V̇O2${{\dot{V}}_{{{{\mathrm{O}}}_2}}}$ and RPE (all P < 0.001). In a semi‐upright position, the increase in CO (7.9 ± 2.8 vs. 6.4 ± 2.6 L/min, P < 0.001), RPE (median (interquartile range): 11 (9–13) vs. 10 (8–12), P = 0.013) and the decrease in SmO2${{S}_{{\mathrm{m}}{{{\mathrm{O}}}_2}}}$ (−38 ± 23 vs. −21% ± 18%, P < 0.001) were greater than upright, while the increase in V̇O2${{\dot{V}}_{{{{\mathrm{O}}}_2}}}$ was attenuated (1.030 ± 0.130 vs. 1.154 ± 0.165 L/min, P < 0.001). These results suggest that while a semi‐upright body position produces elevations in CO, these elevations do not seem to perfuse the active skeletal muscle. This may explain the elevation in RPE despite a blunting in the increase in V̇O2${{\dot{V}}_{{{{\mathrm{O}}}_2}}}$. Further work is required to understand the effects of a semi‐upright exercise position on skeletal muscle activation and lower limb blood flow. [ABSTRACT FROM AUTHOR]

Cell-based test methods with a phenotypic readout are frequently used for toxicity screening. However, guidance on how to validate the hits and how to integrate this information with other data for purposes of risk assessment is missing. We present here such a procedure and exemplify it with a case study on neural crest cell (NCC)-based developmental toxicity of picoxystrobin. A library of potential environmental toxicants was screened in the UKN2 assay, which simultaneously measures migration and cytotoxicity in NCC. Several strobilurin fungicides, known as inhibitors of the mitochondrial respiratory chain complex III, emerged as specific hits. From these, picoxystrobin was chosen to exemplify a roadmap leading from cell-based testing towards toxicological predictions. Following a stringent confirmatory testing, an adverse outcome pathway was developed to provide a testable toxicity hypothesis. Mechanistic studies showed that the oxygen consumption rate was inhibited at sub-µM picoxystrobin concentrations after a 24 h pre-exposure. Migration was inhibited in the 100 nM range, under assay conditions forcing cells to rely on mitochondria. Biokinetic modeling was used to predict intracellular concentrations. Assuming an oral intake of picoxystrobin, consistent with the acceptable daily intake level, physiologically based kinetic modeling suggested that brain concentrations of 0.1–1 µM may be reached. Using this broad array of hazard and toxicokinetics data, we calculated a margin of exposure ≥ 80 between the lowest in vitro point of departure and the highest predicted tissue concentration. Thus, our study exemplifies a hit follow-up strategy and contributes to paving the way to next-generation risk assessment. [ABSTRACT FROM AUTHOR]

Coalfield fires have become a major hidden danger in mining operations. In order to analyze the laws of coal oxidation and combustion under stress, a uniaxial pressurized experiment was conducted on briquettes. The results show that as the temperature rises, the oxygen consumption rate of the oxidative combustion of the coal sample increases. This rate is higher in the active stage (120–200°C). CO and CO2 gases begin to be generated in the awakening stage (60–70°C), while hydrocarbon gases are gradually generated in the active stage. Additionally, the index gas escape rate is relatively high under a specific axial pressure (4MP). The cross point temperature of the coal sample at 4MP is lower (86.9°C), and the maximum heating rate is higher (0.117°C/s) compared to other coal-oxygen samples with axial pressure applied. The application of axial pressure has two functions including opening pore channels and compacting particle space, which affect the oxidative spontaneous combustion of coal samples. The research results provide a strong scientific basis and theoretical guidance for the detection and prevention of coalfield fires. [ABSTRACT FROM AUTHOR]

Background: Most sex comparisons in endurance sports have been derived from performance-matched groups of female and male athletes competing over similar distances within summer sports. Corresponding analyses of sex differences in winter endurance sports have not previously been conducted. In the Olympic Winter Games (OWG), the endurance sports include cross-country skiing (XCS), biathlon (BIA), Nordic combined (NC), ski mountaineering (SkiMo) and long-track speed skating (SpSk). The aim of this narrative review is to provide a comprehensive analysis of the sex differences in performance and performance-determining factors in the OWG endurance sports. Main Body: Sex differences in competition speeds are ~ 7–16% in XCS, 12–16% in BIA and 7–11% in SpSk, with race distances often shorter for women compared to men. No comparable data have been published for NC or SkiMo. Slower skiing speeds among women are associated with greater use of the diagonal and gear 2 sub-techniques in classic and skate skiing, respectively. In SpSk, slower skating speeds among women may be related to a less effective push-off being maintained throughout races. Laboratory data have revealed absolute and relative peak aerobic capacity to be 30–63% and 10–27% greater, respectively, in male versus female XCS, BIA, NC, SkiMo and SpSk athletes. There is limited evidence of sex differences in training characteristics, although women currently tend to complete more strength training than men in XCS and BIA. Of note, most data have been derived from studies performed in XCS, with almost no studies investigating sex differences in NC or SkiMo. Conclusions: This review provides a comprehensive overview of sex differences in performance and performance-determining factors within and between OWG endurance sports, which provides a scientific basis for designing training programs and future studies. Due to the lack of research investigating sex differences in NC and SkiMo, these sports, in particular, would be worthy of further attention. Key Points: This narrative review provides a novel and comprehensive analysis of sex differences in performance and performance-determining factors in the Olympic winter endurance sports. Sex differences in competition speeds are ~ 7–16% in cross-country skiing, biathlon and speed skating, while no comparable data were available for Nordic combined or ski mountaineering. Since men have historically skied and skated over greater distances than women in cross-country skiing, biathlon and speed skating competitions, the "true" sex differences in performance are likely larger than the differences reported in the literature, therefore exceeding the differences typically reported for summer endurance sports. Most information about sex differences in Olympic winter endurance sports is based on studies performed in cross-country skiing. The conspicuous lack of information on Nordic combined and ski mountaineering warrants further research in these sports. [ABSTRACT FROM AUTHOR]

This research was conducted to determine the connections between dissolved oxygen (DO), chemical oxygen demand (COD), permanganate index (CODMn), five-day biochemical oxygen demand (BOD5), and ammonia nitrogen (NH3-H) across five reservoirs of Yunmeng County, China, from January to November 2022. Each month, water samples were collected and subjected to analysis using standard methods. The samples were collected and analyzed using standard methods: dissolved oxygen was determined using the electrochemical probe method, COD was measured via the rapid digestion spectrophotometric method, CODMn was detected using the potassium permanganate oxidation method, BOD5 was determined using the dilution and inoculation method, and NH3-N was measured by using the Nessler reagent spectrophotometry method. The results confirmed strong positive correlations between COD and CODMn, with different intensities from reservoir to reservoir. More specific and demanding COD parameters were used to estimate the level of oxygen consumption; hence, a more variable correlation strength was observed between BOD5 and the other two parameters. Thus, BOD5 was found to be the main indicator of biodegradable organic matter and bacterial oxygen consumption. However, the results were negative, showing a decreasing trend. This means that the oxygen content was lower in the majority of reservoirs, which is attributed to the decomposition of ammonia nitrogen and the presence of organic matter. These findings significantly contribute to the development of appropriate programs for efficient water quality monitoring and the development of reservoir-specific management strategies. This study suggests that there is a need for continuous monitoring of these parameters, together with the extension of the program to additional reservoirs and water quality indicators, along with the use of advanced modeling techniques to clarify the underlying factors that connect water quality parameters in these complex reservoir ecosystems. [ABSTRACT FROM AUTHOR]

Background Methods Results Discussion Evaluation of additive solutions, storage containers, new collection and storage methods, and other potential modifications is resource intensive, resulting in diversion of platelets away from blood bank inventories and significant time to complete study recruitments. Our goal was to evaluate the feasibility of a small bag for the study of platelet storage, and, by using a standardized respirometry test, separate daily metabolic capacity from observations made in the dynamic storage environment of changing pH, fuels, and end products.Single‐donor apheresis platelets collected in 100% plasma had small volumes removed to meet secondary processing requirements. Small volumes (23 ± 1.4 mL) were placed in 50‐mL bags constructed of platelet storage material, stored 7 days, and assessed with a panel of in vitro assays. Platelet bioenergetics (oxygen consumption and acid production rates) were measured with a respirometer.The patterns of platelet pH decline, activation, and potency by thrombin generation were consistent with historical reports. Lactate production rates (54.1 ± 11.3 μmol/1012plt/h) were significantly correlated with pH decrease, increased activation, and thrombin generation potency by Day 7. Respirometry revealed a reduction of the glycolytic capacity and accumulating damage to the oxidative system for ATP production over storage.Small bags present a storage profile of metabolic changes and activation consistent with historical data for full bag storage. Therefore, this system has promise to provide a platform for scaling experiments of platelet storage in a manner that maximizes platelets collected in research settings and does not compromise availability for patient treatment as exercised in this study. [ABSTRACT FROM AUTHOR]

Meat quality holds significant importance for both consumers and meat producers. Various factors influence meat quality, and among them, mitochondria play a crucial role. Recent studies have indicated that mitochondria can sustain their functions and viability for a certain duration in postmortem muscles. Consequently, mitochondria have an impact on oxygen consumption, energy metabolism, and apoptotic processes, which in turn affect myoglobin levels, oxidative stress, meat tenderness, fat oxidation, and protein oxidation. Ultimately, these factors influence the color, tenderness, and flavor of meat. However, there is a dearth of comprehensive summaries addressing the effects of mitochondria on postmortem muscle physiology and meat quality. Therefore, this review aims to describe the characteristics of muscle mitochondria and their potential influence on muscle. Additionally, a suitable method for isolating mitochondria is presented. Lastly, the review emphasizes the regulation of oxygen consumption, energy metabolism, and apoptosis by postmortem muscle mitochondria, and provides an overview of relevant research and recent advancements. The ultimate objective of this review is to elucidate the underlying mechanisms through which mitochondria impact meat quality. [ABSTRACT FROM AUTHOR]

This study investigated whether continuously playing Onigokko, a game similar to tag, could enhance children's cognitive flexibility, a component of executive function, and improve cardiovascular endurance. The intervention group comprised 34 students enrolled in the second-grade A class of H elementary school in Y prefecture. The control group comprised 34 students enrolled in the second-grade B class at the same school. Cognitive flexibility was assessed using the Trail Making Test Task B (TMT-B), while cardiovascular endurance was measured using a 20-meter shuttle run. These measurements were taken for both groups before and after four weeks playing Onigokko with the intervention group. A two-way ANOVA was applied for each measurement item, considering the group (intervention and control groups) and measurement period (pre and post). A significant interaction was found between cognitive flexibility (TMT-B response time) and cardiovascular endurance (20-meter shuttle run count and maximal oxygen consumption [VO2Max]); thereafter, a simple main effect test (Bonferroni method) was conducted. The results revealed that the intervention group's cognitive flexibility (TMT-B response time) and cardiovascular endurance (20-meter shuttle run count and VO2Max) significantly improved post-intervention compared to the control group. These findings suggest that continuously playing Onigokko can significantly enhance both cognitive flexibility and cardiovascular endurance among early elementary school students. [ABSTRACT FROM AUTHOR]

Trypanosoma cruzi, the causative agent of Chagas disease, depends on acquiring nutrients and cofactors, such as copper (Cu), from different hosts. Cu is essential for aerobic organisms, but it can also be toxic, and so its transport and storage must be regulated. In the present study, we characterized the effects of changes in Cu availability on growth behavior, intracellular ion content and oxygen consumption. Our results show that copper is essential for epimastigote proliferation and for the metacyclogenesis process. On the other hand, intracellular amastigotes suffered copper stress during infection. In addition, we identify gene products potentially involved in copper metabolism. Orthologs of the highly conserved P‐type Cu ATPases involved in copper export and loading of secreted enzymes were identified and named T. cruzi Cu P‐type ATPase (TcCuATPase). TcCuATPase transcription is upregulated during infective stages and following exposure to copper chelators in the epimastigote stage. Homolog sequences for the high affinity import protein CTR1 were not found. Instead, we propose that the T. cruzi iron transporter (TcIT), a ZIP family transporter, could be involved in copper uptake based on transcriptional response to copper availability. Further canonical copper targets (based on homology to yeast and mammals) such as the T. cruzi ferric reductase (TcFR) and the cupro‐oxidase TcFet3 are upregulated during infective stages and under conditions of intracellular copper deficiency. In sum, copper metabolism is essential for the life cycle of T. cruzi. Even though cytosolic copper chaperons were not identified, we propose a previously undescribed model for copper transport and intracellular distribution in T. cruzi, including some conserved factors such as TcCuATPase, as well as others such as TcFR and TcIT, playing novel functions. [ABSTRACT FROM AUTHOR]

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Supplemental Digital Content is Available in the Text. Poulios, A, Fotiou, C, Draganidis, D, Avloniti, A, Rosvoglou, A, Batrakoulis, A, Tsimeas, P, Papanikolaou, K, Deli, CK, Stampoulis, T, Douroudos, II, Chatzinikolaou, A, Jamurtas, AZ, and Fatouros, IG. The energy expenditure associated with body-weight resistance exercises of various movement patterns performed at different durations. J Strength Cond Res 38(12): 2034–2046, 2024—Although body-weight resistance exercises (BWRE) are popular and effective for body mass reduction and neuromuscular performance, limited information exists regarding their total energy expenditure (TEE). This study determined the energy cost associated with seven BWRE of different movement patterns plank, push-ups, squat, single-leg squat [SLS], forward lunge [FL], burpees, and jumping jacks [JJ] using 2 different durations (T30: 30-second; T45: 45-second) in 10 healthy young adults using a randomized, 2-trial, crossover, repeated-measures design. The level of significance was set at p ≤ 0.05. The burpees were associated with the highest and the plank with the lowest intensity (rates of perceived exertion [RPE] and mean heart rate [MHR]) and metabolic load (blood lactate [BL] accumulation, metabolic equivalents of task [METs], and excess post-exercise oxygen consumption [EPOC]) in both trials. In T30 and T45, TEE (kcals per minute) was 11.3/12.6 in plank, 18.6/22.0 in FL, 19.8/21.2 in SLS, 19.9/23.2 in squat, 22.0/24.9 in push-ups, 23.1/22.8 in JJ, and 32.2/40.7 in burpees. Although RPE, MHR, BL, and EPOC were comparable among T30 and T45, METs and TEE were greater in T45. These results suggest that TEE of BWRE ranges from ∼11 to 40 kcals·min−1, depending on the movement pattern and the duration of exercise. This information may be valuable for those using BWRE for body-weight management and improvement of strength performance. [ABSTRACT FROM AUTHOR]

McCarthy, SF, Bornath, DPD, Murtaza, M, Ormond, SC, and Hazell, TJ. Effect of resistance training load on metabolism during exercise. J Strength Cond Res 38(12): 2029–2033, 2024—The effect of resistance training (RT) load on energy expenditure during exercise is unclear as most studies match low-load and high-load RT based on volume or total repetitions and matching volume can attenuate benefits of low-load protocols. This study explored the effect of whole-body low-load and high-load RT completed to volitional fatigue (not volume or repetition matched) on metabolism during exercise. Eleven resistance-trained adults (22 ± 2 years, 3 F) completed 3 experimental sessions: (a) no-exercise control (CTRL); (b) RT at 30% 1 repetition maximum (1RM; 30%); and (c) RT at 90% 1RM (90%) with oxygen consumption ( V ˙ o 2) and heart rate measured continuously. The RT sessions consisted of 3 sets of back squats, bench press, straight-leg deadlift, military press, and bent-over rows to volitional fatigue completed sequentially with 90 seconds rest between sets and exercises. Changes were considered important if p < 0.100 with a greater than medium effect size. There were main effects of session for relative and absolute V ˙ o 2 (L·min−1; p < 0.001, η p 2 > 0.935), both 30 and 90% were greater than CTRL (p < 0.001, d > 4.33) with no differences between RT protocols (p > 0.999, d = 0.28). There was a main effect of session for total O2 consumed (L; p < 0.001, η p 2 > 0.901), both RT sessions were greater than CTRL (p < 0.001, d > 3.08), and 30% was greater than 90% (p = 0.002, d = 1.75). Taken together these data suggest that RT load does not affect metabolism during exercise when completing whole-body exercises to volitional fatigue, though lower loads may result in longer session duration generating a greater total amount of O2 consumed simply because of the extended duration. [ABSTRACT FROM AUTHOR]

mHealth interventions provide unique opportunities for reducing noncommunicable disease risk factors in workplace. They can be useful in promoting positive health behaviors among employees and can be leveraged, among others, to improve step counts, physical activity, and cardiorespiratory fitness. Objective: This study aimed to test the efficacy of a mHealth-based workplace health promotion strategy in improving cardiorespiratory fitness in a healthcare setting. Methods: Seventy-seven female nurses (age, 30–45 years) meeting the inclusion criteria underwent baseline assessment and received either a 12-week mHealth or awareness intervention based on their workplace. Changes in peak oxygen consumption (VO2), fasting blood sugar, and physical activity were compared within and between the groups at the end of the intervention. Results: Thirty-seven and 33 participants in the mHealth and awareness arms, respectively, completed the 12-week intervention. Peak VO2 (1.6 mL/kg/min, 7%), physical activity, and step counts improved significantly in the mHealth arm. However, between-group differences were not significant. Conclusions: mHealth interventions offer unique opportunities to improve physical activity and cardiorespiratory fitness among health professionals in their workplace. [ABSTRACT FROM AUTHOR]

Flatworms are among the best studied animal models for regeneration; however, they also represent an emerging opportunity to investigate other biological processes as well. For instance, flatworms are nocturnal and sleep during the day, a state that is regulated by sleep/wake history and the action of the sleep‐promoting neurotransmitter gamma‐aminobutyric acid (or GABA). Sleep is widespread across the animal kingdom, where it serves many nonexclusive functions. Notably, sleep saves energy by reducing metabolic rate and by not doing something more energetically taxing. Whether the conservation of energy is apparent in sleeping flatworms is unclear. We measured the oxygen consumption rate (OCR) of flatworms dosed with either (1) GABA (n = 29) which makes flatworms inactive or (2) dopamine (n = 20) which stimulates flatworms to move, or (3) day and night neurotransmitter‐free controls (n = 28 and 27, respectively). While OCR did not differ between the day and night, flatworms treated with GABA used less oxygen than those treated with dopamine, and less than the day‐time control. Thus, GABA affected flatworm physiology, ostensibly by enforcing energy‐conserving sleep. Evidence that dopamine increased metabolism was less strong. This work broadens our understanding of flatworm physiology and expands the phylogenetic applicability of energy conservation as a function of sleep. Research Highlights: While flatworms are known to sleep, it has been unclear whether restful flatworms reap the metabolic benefits of this quiescent state. Using neurotransmitters that regulate sleep and wakefulness, we show that sleep‐promoting gamma‐aminobutyric acid reduces oxygen consumption in flatworms. [ABSTRACT FROM AUTHOR]

The study aimed to evaluate the effects of varying frequencies (1 vs. 2 vs. 3) of short sprint interval training (sSIT) on young male soccer players' physical performance and physiological parameters. Forty young male soccer players were randomly assigned to four experimental groups engaging in 36 trials sSIT for a duration of 6 weeks as follows: once weekly (1sSIT = 4 sets of 9 x 5 sec all-out runs), twice weekly (2sSIT = 2 sets of 9 x 5 sec all-out runs), and three times weekly (3sSIT = 2 sets of 6 x 5 sec all-out runs), or an active control group which continued their soccer practice routines. Before and after the 6-week training period, physical performance (countermovement vertical jump, 20-m sprint, Illinois change of direction, Yo-Yo intermittent recovery level 1 [Yo-Yo IR 1] and kicking distance) and physiological parameters (cardiorespiratory fitness, peak and average power output) were evaluated. All sSIT groups demonstrated significant (p < 0.01) and small to very large training effects (i.e., effect size) on measured parameters. More importantly, a comparison of inter-individual variability in the adaptive changes revealed that the 3sSIT group results in lower residuals in changes in cardiorespiratory fitness and anaerobic power, coupled with lower coefficient of variations in the mean group changes and perceived exertion throughout the training period. The findings indicate that incorporating one, two, or three weekly sessions of sSIT into routine soccer training can lead to similar enhancements in soccer players' physiological and performance adaptations. More importantly, higher training frequencies result in more homogenized adaptations among team members by reducing inter-individual variability in the magnitude of the adaptive responses. [ABSTRACT FROM AUTHOR]

This study compared inter-individual variability in the adaptive responses of cardiorespiratory fitness, anaerobic power, and motor abilities of male volleyball players to high-intensity interval training (HIIT) prescribed as repetitive drop jumps (interval jumping) and running-based intervals (interval running). Twenty-four collegiate volleyball players were equally randomized to two training groups executing 11 minutes of interval running or interval jumping during which they ran or repeated drop-jumps for 15 seconds, alternating with 15 seconds of passive recovery. Before and after the 6-week training period, aerobic fitness, cardiac function, and anaerobic power were evaluated using a graded exercise test, impedance cardiography, and a lower-body Wingate test, respectively. Additionally, linear speed, agility, and jumping tests determined motor abilities. Both interventions significantly enhanced maximum oxygen uptake (VO2max), velocity associated with VO2max, first and second ventilatory thresholds (VT1 & VT2), maximal cardiac output (Qmax), stroke volume (SVmax), peak and average power output, vertical jump, change of direction, and linear sprint speed. Interval jumping group demonstrated a significantly greater improvement in squat jump (p = 0.001; 95% CI: 2.51 - 5.42) and countermovement jump (p = 0.001; 95% CI: 2.11 - 4.61) compared to interval running group. Conversely, interval running group elicited a greater enhancement in sprint speed (p = 0.002; 95% CI: 2.53 - 5.71) than interval jumping group. Examining the individual residual in the adaptive responses revealed that interval running induced more homogenized adaptations across individuals in VT1 (p = 0.04; 95% CI: 0.03 - 1.33), Qmax (p = 0.03; 95% CI: 0.04 - 1.64), SVmax (p = 0.04; 95% CI: 0.02 - 1.75), and maximal sprint speed (p = 0.01; 95% CI: 0.72 - 1.95) in contrast to interval jumping. However, the uniformity of adaptations in countermovement jump in response to interval jumping surpassed that of interval running (p = 0.02; 95% CI: 0.08 - 1.32). Although both training modalities effectively improved the mentioned variables concurrently, tailoring the HIIT intervention to the reference intensity and training modality specific for each quality may enhance measured quality. [ABSTRACT FROM AUTHOR]

Supplementary high-intensity interval training (HIIT) programs, focusing on different aspects of fitness, are commonly used in soccer practice. This study examined the impact of two different HIIT formats applied during the competitive season on aerobic and neuromuscular performance. Twenty-six young players from two youth amateur soccer teams (aged 18.1 ± 0.7 and 18.7 ± 1.1 years) participated. In a randomized design, Team A served as an experimental group, performing either a 10s/10s linear running HIIT or a 15s/15s HIIT with changes of direction, both at 100% of maximum aerobic speed, twice per week for six weeks. In that period, team B acted as a control group, maintaining their usual training soccer regimen. Following two weeks of lower volume and frequency training, team B added the two HIIT formats in their training for six weeks, while team A acted as control. Before and after each 6-weeks period, aerobic fitness and neuromuscular performance was evaluated by the countermovement jump (CMJ). The 3-way ANOVA showed that both HIIT formats significantly enhanced Yo-Yo Intermittent Recovery Test Level 1 (Yo-YO IR1) performance compared to the respective control periods. However, the main finding was that the 10s/10s compared with the 15s/15s HIIT format induced 45 - 50% greater improvements in Yo-YO IR1 (total distance: 18.5 ± 11.7% vs. 9.0 ± 8.5%, VO2max: 5.6 ± 3.2% vs. 3.0 ± 2.7%, and vVO2max: (3.3 ± 1.9% vs. 1.8 ± 1.7%, all p = 0.39, d = 0.85). Countermovement jump performance remained unchanged across both groups (p > 0.68). During HIIT rating of perceived exertion was higher in the 15s/15s vs. the 10s/10s format (6.4 ± 0.5 vs. 4.7 ± 1.2 a.u., p < 0.001). These findings suggest that while both HIIT formats effectively enhance aerobic performance during the season, the 10s/10s format offers superior benefits with less perceived exertion, while the 15s/15s format induces higher internal load. [ABSTRACT FROM AUTHOR]

Ischemic preconditioning (IPC) is a strategy that may enhances endurance performance in thermoneutral environments. Exercising in the heat increases thermoregulatory and cardiovascular strain, decreasing endurance performance. The current study aimed to determine whether IPC administration improves endurance performance in the heat. In a randomized crossover design, 12 healthy subjects (VO2max: 54.4 ± 8.1 mL⋅kg-1⋅min-1) underwent either IPC administration (220 mmHg) or a sham treatment (20 mmHg), then completed a moderate-intensity 6-min running (EX1) and a high-intensity time-to-exhaustion running test (EX2) in a hot environment (35 °C, 50 % RH). Cardiac function, oxygen consumption (VO2), and core body temperature (TCORE) were measured. During EX2, IPC administration increased the total running time in the heat compared to the sham treatment (IPC: 416.4 ± 61.9 vs. sham 389.3 ± 40.7 s, P = 0.027). IPC administration also increased stroke volume (IPC: 150.4 ± 17.5 vs. sham: 128.2 ± 11.6 ml, P = 0.008) and cardiac output (IPC: 27.4 ± 1.7 vs. sham: 25.1 ± 2.2 ml⋅min-1, P = 0.007) during 100% isotime of EX2. End-exercise VO2 (IPC: 3.72 ± 0.85 vs. sham: 3.54 ± 0.87 L⋅min-1, P = 0.017) and slow phase amplitude (IPC: 0.57 ± 0.17 vs. sham: 0.72 ± 0.22 L⋅min-1, P = 0.016) were improved. When compared with the baseline period, an increase in TCORE was less in the IPC condition during EX1 (IPC: 0.18 ± 0.06 vs. sham: 0.22 ± 0.08 °C, P = 0.005) and EX2 (IPC: 0.87 ± 0.10 vs. sham: 1.03 ± 0.10 °C, P < 0.001). IPC improves high-intensity endurance performance in the heat by 6.9 %. This performance benefit could be associated with improved cardiac and thermoregulatory function engendered by IPC administration. [ABSTRACT FROM AUTHOR]

Simple Summary: CR6 interacting factor 1 (CRIF1) plays an essential role in the regulation of mitochondrial function. We provide important details to demonstrate that CRIF1 deletion-induced mitochondrial damage has an antitumor effect via TIGAR induction in BT549 breast cancer cells. CRIF1 deficiency results in OXPHOS dysfunction, which has been investigated as a potential therapeutic target for the treatment of cancer. Background/Objectives: Mitochondrial oxidative phosphorylation (OXPHOS) has been exploited as a therapeutic target in cancer treatments because of its crucial role in tumorigenesis. CR6-interacting factor 1 (CRIF1), a mitochondrial ribosomal subunit protein, is essential for the regulation of mitochondrial OXPHOS capacity. However, the mechanism of CRIF1 in triple-negative breast cancer (TNBC) cells remains unclear. Methods/Results: We showed that the downregulation of CRIF1 reduced cell proliferation in the TNBC cell lines MDA-MB-468, MDA-MB-231, and, especially, BT549. In addition, wound scratch and Transwell assays showed that CRIF1 deficiency inhibited the migration and invasion of BT549 cells. CRIF1 downregulation resulted in the suppression of mitochondrial bioenergetics in BT549 cells, specifically affecting the inhibition of OXPHOS complexes I and II. This was evidenced by a decrease in the mitochondrial oxygen consumption rate and the depolarization of the mitochondrial membrane potential. Damage to mitochondria resulted in a lower adenosine triphosphate level and an elevated production of mitochondrial reactive oxygen species. In addition, CRIF1 deficiency decreased hypoxia-inducible factor 1α accumulation, NADPH synthesis, and TP53-induced glycolysis and apoptosis regulator (TIGAR) expression in BT549 cells. These events contributed to G0/G1-phase cell cycle inhibition and the upregulation of the cell cycle protein markers p53, p21, and p16. Transfection with a TIGAR overexpression plasmid reversed these effects and prevented CRIF1 downregulation-induced proliferation and migration reduction. Conclusions: These results indicate that blocking mitochondrial OXPHOS synthesis via CRIF1 may have a therapeutic antitumor effect in BT549 TNBC cells. [ABSTRACT FROM AUTHOR]

Background: Since 1989, FIFA has used a battery of physical tests to evaluate the fitness levels of soccer referees. However, to date, there is no consensus, and the specificity, reliability, and validity of these tests remain a matter of debate. Aims: Develop a new specific field test to assess the fitness level of field soccer referees. Methods: Oxygen consumption (VO2) of 12 male professional field soccer referees was directly measured with a portable metabolic gas analysis system during two incremental protocols: treadmill and a Yo-Yo IE2 adapted in-field test (ADYYIE2). Physiological performance was measured by GPS methodology. Results: The distance covered until exhaustion between the protocols was 2098.61 ± 425.72 and 1025.83 ± 304.89 m, for the treadmill and ADYYIE2 protocols, respectively (p < 0.0001). Time to exhaustion during the treadmill protocol was also significantly higher than that observed in the ADYYIE2 test. The VO2peak measured were not significantly different between the protocols. A significant correlation was obtained between the total distance covered during the ADYYIE2 test and VO2peak, but the relationship between the treadmill protocol and VO2peak was not significant. The VO2peak values obtained during the ADYYIE2 test showed a correlation of very large magnitude with the total distance covered and the amount of high intensity activities recorded during an official match. Therefore, these match activities are related to the physical capacity of the referee evaluated by the test proposed. Conclusions: This study is the first to direct assessment the VO2peak during a Yo-Yo test performance (via portable spirometry), and the main finding was that direction change influences the physiological parameters assessed during physical tests. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the effect of repeated sprint in hypoxia (RSH) training in mask vs. tent system on the physiological parameters associated with the cyclist's performance. Sixteen well-trained cyclists (VO2max 66 ± 5.9 mL/kg/min) participated in a randomised and two parallel groups design. Participants were assigned to different hypoxia methods [RSHMask (n = 8) vs RSHTent (n = 8)]. The sprint number and power output were measured during a repeated sprint test to failure before and after the effect of eight sessions of RSH. In addition, the following physiological parameters were evaluated: oxygen consumption (VO2), heart rate (HR), arterial oxygen saturation (SpO2), muscle oxygen saturation (SmO2), lactate and core temperature (CoreT°). Linear mixed models were used for repeated measures (p value < 0.05), and the effect size (ES) between groups was reported. An inter-individual analysis of participants was also reported. There was an increase in sprint numbers in both groups (ES = 0.167, p = 0.023) and an increase in power output (∑w) in the RSHMask group (ES = 0.095, p = 0.038). The RSHMask group showed improvement in VO2 recovery (ES = 0.096, p = 0.031) and SmO2 desaturation % (ES = 0.112, p = 0.042) compared to the RSHTent group. Likewise, 50% of the participants in RSHTent showed adaptations to withstand higher T°Core (+ 0.45°), and eight participants showed lactate decreases between 2.9 and 3.1 mmol/L (−24%) after RSH in both groups. Generally, RSH improves the cyclist's performance, whether the mask or tent method is used. However, RSHTent has the advantage of causing adaptations in T°Core, whilst RSHMask improves anaerobic performance in the oxygenation of peripheral muscles. [ABSTRACT FROM AUTHOR]

Purpose: Apnea duration is dependent on three factors: oxygen storage, oxygen consumption, hypoxia and hypercapnia tolerance. While current literature focuses on maximal apneas to improve apnea duration, apnea trained individuals use timed-repeated submaximal apneas, called "O2 and CO2 tables". These tables claim to accommodate the body to cope with hypoxia and hypercapnia, respectively. The aim of this study was twofold. First, to investigate the determinants of maximal apnea duration in apnea novices. Second, to compare physiologic responses to maximal apneas, O2 and CO2 tables. Methods: After medical screening, lung function test and hemoglobin mass measurement, twenty-eight apnea novices performed three apnea protocols in random order: maximal apneas, O2 table and CO2 table. During apnea, peripheral oxygen saturation (SpO2), heart rate (HR), muscle (mTOI) and cerebral (cTOI) tissue oxygenation index were measured continuously. End-tidal carbon dioxide (EtCO2) was measured before and after apneas. Results: Larger lung volumes, higher resting cTOI and lower resting EtCO2 levels correlated with longer apnea durations. Maximal apneas induced greater decreases in SpO2 (− 16%) and cTOI (− 13%) than O2 (− 8%; − 8%) and CO2 tables (− 6%; − 6%), whereas changes in EtCO2, HR and mTOI did not differ between protocols. Conclusion: These results suggest that, in apnea novices, O2 and CO2 tables did not induce a more profound hypoxia and hypercapnia, but a similar reduction in oxygen consumption than maximal apneas. Therefore, apnea novices should mainly focus on maximal apneas to improve hypoxia and hypercapnia tolerance. The use of specific lung training protocols can help to increase oxygen storage capacity. [ABSTRACT FROM AUTHOR]

To test the reliability of the VO 2 Master Pro and to compare it to the Cosmed Quark. Eight recreational cyclists participated in two different trials which consisted of graded cycling exercise stages at 50%, 70%, and 85% of their critical power. The VO 2 Master Pro was used during the first visit, while both the VO 2 Master Pro and Cosmed Quark were used during the second visit. Equivalence testing of the trials was done by TOST analysis while test of difference was done by ANOVA. The results indicated equivalence of the VO 2 Master Pro in the measurement of VO 2 (35.1 ± 10.4 mL·kg−1·min−1 vs. 35.4 ± 10.2 mL·kg−1·min−1) and V E (72.4 ± 20.5 L·min−1 vs 73.8 ± 22.3 L·min−1) across repeated visits indicating good reliability of the device. However, neither significant equivalence nor difference was detected when comparing the VO 2 Master Pro to the Cosmed Quark across the same variables indicating that the two devices were similar to each other. [ABSTRACT FROM AUTHOR]

To explore if individuals living with obesity participate, have interest, and benefit from circuit resistance training (RT+) and evaluate if the RT+ reaches moderate aerobic intensity and the association between oxygen consumption and heart rate while performing the RT+. Ten inactive adults living with obesity participated in the RT+ program for 12 weeks. Participants performed 150 min of the RT+ program using four exercises (squats, chest press, lunges and lat-pull down) for three sessions of 50 min each week. Measured outcomes included attendance, fitness, lipids, anthropometrics body composition. Oxygen consumption and heart rate were captured during a single session of the RT+ program using portable indirect calorimetry. Participants attended 90% of offered sessions (32.5/36.0 sessions). A significant improvement was observed in the body mass index (P = 0.03). The RT+ program was permitted to reach moderate intensity regardless of the indicator used to establish moderate intensity (3METs, 46%VO 2peak , 40%VO 2reserve , 64%HR max and 40%HR reserve). The association between HR and VO 2 while performing the RT+ program was 0.27; P < 0.01. This study suggests that people with obesity achieve moderate intensity when performing RT+. As a result, performing RT in a circuit manner could contribute to the aerobic portion of the guidelines for adults living with obesity. [ABSTRACT FROM AUTHOR]

González-García, Mauricio and Luis Ernesto Téllez. Adaptation to living at high altitude in patients with COPD. Comparative study of exercise capacity and ventilatory variables between patients residing at high and low altitudes in the Andes. High Alt Med Biol. 25:266–273, 2024. Introduction: Although some variables related to oxygen transport and utilization such as ventilation, pulmonary vascular responses to hypoxia, heart rate (HR), cardiac output, hemoglobin (Hb), and oxygen saturation (SpO2) are used to compare adaptation to altitude between populations, peak oxygen consumption (VO2) constitutes an integrative measure of total oxygen transport that may reflect successful adaptation to altitude. We designed this study to make a direct comparison of VO2 in a cardiopulmonary exercise test (CPET) between chronic obstructive pulmonary disease (COPD) patients residing at high altitude (Bogotá, Colombia: 2,640 m) (COPD-HA) and those living at low altitude (Bucaramanga, Colombia: 959 m) (COPD-LA). Methods: All patients performed a CPET with measurements of VO2, minute ventilation (VE), HR, oxygen pulse (VO2/HR), ventilatory equivalents (VE/VCO2), and SpO2. Unpaired T-test or Mann–Whitney U test were used for comparisons between COPD-HA and COPD-LA. Results: We included 71 patients with COPD, 53 COPD-HA, and 18 COPD-LA. There were no differences between groups in age, sex, or forced expiratory volume in 1 second. The means ± SD of Hb, g/dl was slightly higher in COPD-HA (15.9 ± 1.9 vs. 14.7 ± 1.8, p = 0.048), without differences in VO2, % pred (71.6 ± 17.9 vs. 69.0 ± 17.0, p = 0.584), VO2/HR, % pred (92.1 ± 22.0 vs. 89.7 ± 19.8, p = 0.733) or VE/MVV, % (75.5 ± 14.1 vs. 76.5 ± 14.3, p = 0.790) at peak exercise between groups. Median (IQR) of VE/VCO2 nadir [38.0 (37.0–42.0) vs. 32.5 (31.0–39.0), p = 0.005] was significantly higher, and SpO2, % at rest [88.0 (86.0–91.0) vs. 95.0 (94.0–96.0), p < 0.001] and at peak exercise [84.0 (77.0–90.0) vs. 93.0 (92.0–95.0), p < 0.001] were significantly lower in COPD-HA. Conclusions: Despite higher desaturation at rest and during exercise in COPD-HA, there were no differences in VO2 peak between COPD-HA and COPD-LA, suggesting a potential altitude adaptation in those patients chronically exposed to hypoxia. [ABSTRACT FROM AUTHOR]

Mactra veneriformis is highly susceptible to ocean acidification (OA) due to its low shell hardness during its rapid growth period. In this study, oxygen consumption rate, ammonia excretion rate, and transcriptome sequencing of mantle tissue analyses were conducted in white and purple shell-color populations of M. veneriformis under OA stress (pH = 7.6). The findings indicated a significant rise in oxygen consumption rates and ammonia excretion rates following acidification in both the two shell colors, while the clams with purple color showed comparatively lower basal metabolic levels. Transcriptomic analyses demonstrated the expression of key genes related to fatty acid synthesis were significantly inhibited, whereas genes involved in calcification, osmoregulation, and immune response were upregulated under OA exposure in the two shell-color groups. However, some genes such as CA and HSP showed a population-specific response between the two shell-color populations. KEGG enrichment analysis revealed that the MAPK signaling pathway and protein processing in the endoplasmic reticulum were significantly enriched in the two acidification groups. This study provides valuable insights into the response of M. veneriformis to OA stress and also helps to predict the future breeding of valuable strains of M. veneriformis. [ABSTRACT FROM AUTHOR]

Mesozoic oceanic anoxic events were characterized by relatively low seawater sulphate concentrations ([SO42−]), which likely regulated the development and evolution of these major palaeoceanographic phenomena. However, there is little reliable sedimentary evidence for low [SO42−] in ancient marine waters and understanding of how such a seawater chemistry potentially impacted oceanic anoxic events is limited. This study presents an integrated sedimentological, mineralogical and geochemical investigation of the mineral siderite hosted in dark grey shale and sideritic concretions of Early Aptian (coeval with Oceanic Anoxic Event 1a) from the Tibetan Himalaya. Siderite is present throughout the section and possesses similar morphological characteristics whether in dark grey shale or concretions. Siderite can be present as disseminated and rhombic crystals formed during early diagenesis, or minor spherical crystals formed during late diagenesis. The evidence from redox elements, middle rare‐earth element bulge patterns and extremely low carbon‐isotope values of the sideritic concretions indicates that the iron carbonate was formed in the Fe‐reduction zones by the process of dissimilatory iron reduction. This process would have required conditions of low [SO42−], reducing environment, abundant iron and high alkalinity. Additionally, the coexistence of siderite and pyrite may indicate that dissimilatory iron reduction occurred close to the microbial sulphate reduction zone, with seawater [SO42−] hovering around the tipping point at which pyrite could form once seawater sulphate increased. Such an increase during Oceanic Anoxic Event 1a could have resulted from basalt–seawater interaction and associated enhanced continental weathering, and/or hydrothermal activity. This study's observations support the previous hypothesis that low [SO42−] for Oceanic Anoxic Event 1a was probably caused by massive gypsum burial in the proto‐South Atlantic. Subsequently, enhanced sulphate input could have promoted microbial sulphate reduction and accompanying oxidation of organic matter, which likely further enhanced nutrient recycling, increased primary productivity and organic‐carbon burial, leading to more oxygen consumption and expansion of oxygen minimum zones, as reconstructed for many oceanic anoxic events. [ABSTRACT FROM AUTHOR]

The article focuses on the relationship between oxidative therapies and anti-aging medicine, discussing the role of mitochondrial function in aging and how oxidative therapies can restore it. Topics include Frank Shallenberger's journey into medicine, his discovery of mitochondrial dysfunction and its early onset, and how ozone therapy works to improve mitochondrial efficiency and reduce aging signs.

N6-methyladenosine (m6A) modification is, a more common epigenetic modification, mainly found in mRNA. More and more researches have shown the important functions of m6A on human cancers. This study seeks to explore the role of hnRNPA2B1 and m6A-dependent mechanism in cervical cancer. Elevated hnRNPA2B1 indicated the poor prognosis of cervical cancer patients. Enforced hnRNPA2B1 reduced the apoptosis, and accelerated the proliferation and migration of cervical cancer cells in vitro. Besides, hnRNPA2B1 promoted the aerobic glycolysis of cervical cancer cells, including the lactate secretion, glucose uptake, ATP production, extracellular acidification rate (ECAR) and oxygen consumption rate (OCR). LDHA was found as the downstream target of hnRNPA2B1 by m6A site. Moreover, hnRNPA2B1 enhanced the mRNA stability of LDHA through m6A-dependent manner. LDHA inhibitor (FX-11) could reverse the effect of hnRNPA2B1. Taken together, the data revealed that hnRNPA2B1 promoted the proliferation, migration and aerobic glycolysis of cervical cancer cells by m6A/LDHA-dependent manner. These findings might bring a new idea for cervical cancer treatment. [ABSTRACT FROM AUTHOR]

Disabling atrial fibrillation (AF)-related symptoms and different testing settings may influence day-to-day cardiopulmonary exercise testing (CPET) measurements, which can affect exercise prescription for high-intensity interval training (HIIT) and moderate-to-vigorous intensity continuous training (M-VICT) and their outcomes. This study examined the reliability of CPET in patients with AF and assessed the proportion of participants achieving minimal detectable changes (MDC) in peak oxygen consumption (V̇O2peak) following HIIT and M-VICT. Participants were randomized into HIIT or M-VICT after completing two baseline CPETs: one with cardiac stress technologists (CPETdiag) and the other with a research team of exercise specialists (CPETresearch). Additional CPET was completed following 12 weeks of twice-weekly training. The reliability of CPETdiag and CPETresearch was assessed by intraclass correlation coefficient (ICC) and dependent t tests. The MDC score was calculated for V̇O2peak using a reliable change index. The proportion of participants achieving MDC was compared between HIIT and M-VICT using chi-square analysis. Eighteen participants (69 ± 7 years, 33% females) completed two baseline CPETs. The ICCs were significant for all measured variables. However, peak power output (POpeak: 124 ± 40 vs. 148 ± 40 watts, p < 0.001) and HR (HRpeak: 136 ± 22 vs. 148 ± 30 bpm, p = 0.023) were significantly greater in CPETresearch than CPETdiag. Few participants achieved MDC in V̇O2peak (5.6 mL/kg/min) with no difference between HIIT (0%) and M-VICT (10.0%, p = 0.244). POpeak and HRpeak differed significantly in patients with AF when CPETs were repeated under different settings. Caution must be practised when prescribing exercise intensity based on these measures as under-prescription may increase the number of exercise non-responders. [ABSTRACT FROM AUTHOR]

Nearly 20 years have elapsed since the first clinical trial investigated the impact of interval training on patients with cardiovascular disease (CVD). This clinical corner discusses the health outcomes of systematic reviews and meta-analyses and appropriately powered randomized clinical trials which have tested these interval training programs across various CVDs (i.e., coronary artery disease, heart failure, atrial fibrillation, peripheral arterial disease, and cardiac implantable electronic devices). The publications included in this clinical corner have shown that interval training leads to similar or superior improvements in peak oxygen uptake (V̇O2peak), functional capacity, pain free walking, quality of life, anxiety, depression, and endothelial function, but the magnitude of improvements across varying protocols (e.g., length and number of work periods, intensities of work periods, duration of exercise sessions, frequency of exercise sessions, and duration of program) and optimal dosage for males and females are unclear across CVD conditions. The heterogeneity in protocols, physical and mental health outcome measures, and lack of sex- and gender-based analyses calls for more high-quality research in this area. [ABSTRACT FROM AUTHOR]

The objective of this case presentation is to identify factors that hinder home deaths after patients have been compassionately discharged from the hospital. It aims to shed light on modifiable factors that could facilitate a home death. Compassionate discharges differ from routine discharges as they are done to support the wishes of terminally ill patients to pass on at home. The two cases selected for detailed analysis were unique in our cohort; they were the only patients admitted to an inpatient hospice after being compassionately discharged to their homes. This study excluded patients who were readmitted to an acute hospital setting for further treatment trials, as their care objectives had changed. A retrospective analysis of medical notes identified several factors associated with the patient's inability to achieve a desired home death. These included a significant increase in nursing needs compared to the pre-admission status, the substantial psychological burden on families caring for a dying relative at home, and the absence of adaptable and sustainable care plans. Therefore, a successful compassionate discharge requires the provision of caregiver training and psychological support to families both before and after discharge. Moreover, healthcare providers must collaborate with families to develop flexible care plans that are sufficiently robust to manage the unpredictable prognoses of patients. [ABSTRACT FROM AUTHOR]

The metabolic rate of a freely moving fish (routine metabolic rate) is tightly coupled with volitional movement (spontaneous activity), both of which commonly show strong daily cycles linked to the species‐specific diel activity pattern. Mummichog (Fundulus heteroclitus), an important estuarine fish in the north western Atlantic Ocean, are historically reported as diurnal (i.e., more active during daylight). Our recent laboratory studies on a Bay of Fundy population, however, showed a free‐running (i.e., similarly active daytime and night‐time) or even nocturnal (i.e., more active at night‐time) diel activity pattern. In the laboratory, near‐infrared (NIR) illumination is commonly used with a NIR‐sensitive camera to visualize fish activity across the light–dark periods of the day. Because NIR light is close to the visible light spectrum and certain fishes show sensitivity to NIR, the use of NIR with mummichog possibly could disturb the animals and obscure the identification of their true diel activity pattern. We aimed to determine if NIR illumination (940 nm wavelength) influences the diel activity pattern of mummichog. We used measurements of routine metabolic rate (oxygen consumption rate, MO2) as a proxy for activity, as evaluating the effect of NIR requires treatments where NIR lights are off, which precludes visualization and direct assessment of fish activity at night‐time. We measured routine MO2 of mummichogs over 6 days, exposed to either NIR off–on–off (2 days for each off or on period) or the opposite sequence of NIR on–off–on (to control for time‐dependent effects). NIR lights did not influence the diel cycle of routine MO2, and activity by proxy, in mummichog. Thus, NIR illumination is a suitable method to visualize mummichog during light–dark diel cycles. Routine MO2, and presumably activity, was similar or higher during night‐time periods compared to daytime periods, confirming a free‐running or nocturnal activity pattern for at least certain populations of mummichog. [ABSTRACT FROM AUTHOR]

Sprint interval training (SIT) leads to similar improvements in maximal oxygen uptake (V̇O2max) and maximal cardiac output as previously reported for traditional endurance training, but the exercise‐induced effects on cardiac remodeling are still largely unknown. The aim of the current study was therefore to explore the effects of SIT on cardiac structure and function assessed by echocardiography in relation to, and controlling for, changes in both blood volume (BV) and heart rate (HR). Healthy men and women (n = 28) performed 6 weeks of SIT. V̇O2max and total BV were measured, and echocardiography was performed before and after the intervention. There was a robust increase in BV (+7.1%; p < 0.001) and V̇O2max (+10.1%; p < 0.001) and a decrease in resting HR (−3.9%; p = 0.013) following the SIT intervention. Machine‐learning‐based feature selection and univariate analysis indicated that several measures of left ventricular dimension (+14.3% LVEDV, p = 0.013; +17.4% LVESV, p = 0.018; +12.3% LVSV, p = 0.031), left ventricular diastolic function (MVA, MVD‐slope, MVDT), and left ventricular stroke volume (LVOT VTI) were altered by 6 weeks of SIT. When controlling for the exercise‐induced changes in BV and HR, left ventricular dimensions remained significantly changed. Our data indicate that several measures of cardiac function are likely only indirectly affected by SIT, driven by increased BV. However, the disproportionate increase in left ventricular size exceeds what can be explained by changes in BV and HR alone, indicating volume‐independent structural cardiac remodeling. [ABSTRACT FROM AUTHOR]

Chronic medical conditions caused by the inadequate adaptation of the body to modern lifestyles, such as physical inactivity and unhealthy diets, are on the rise. This study assessed whether a comprehensive lifestyle intervention, including high volumes of supervised exercise, could improve health outcomes. Eight volunteers with lifestyle‐related diseases received a 6‐month lifestyle intervention consisting of 8000–10 000 steps/day, 6 moderate‐intensity endurance and 3 resistance training sessions per week, a 5‐week long hike, and dietary advice. This was followed by 7 months of limited remote supervision, ending 13 months from baseline. The participants (3 females, 5 males; mean age 42.9 years) had conditions including type 2 diabetes (T2D), depression/stress, and metabolic syndrome (MS). After 6 months, body weight decreased significantly by 23 kg (95% CI; −33.7 to −12.2), with a minor non‐significant decrease in lean body mass of 1.96 kg (95% CI; −4.34 to 0.27). Maximal oxygen consumption (VO2max) increased by 18.5 mL/O2/kg/min. (95% CI; 13.8–23.1) and systolic and diastolic blood pressures decreased by 33 (95% CI; −39 to −26) and 18 mmHg (95% CI; −23 to −14), respectively. Three of the 4 participants with T2D had normalized glycated hemoglobin (HbA1c) levels, and all showed improved 2‐h oral glucose tolerance (OGTT) without pharmacological treatment. Participants with T2D continued to lower HbA1c during the 7‐month follow‐up period. This 6‐month lifestyle intervention restored metabolic health and improved cardiovascular health in 8 participants with lifestyle‐related diseases while reducing the need for pharmacological treatments. These findings suggest that comprehensive lifestyle changes can reverse several medical conditions caused by evolutionary mismatch. [ABSTRACT FROM AUTHOR]

Purpose: Vigorous intermittent lifestyle physical activity (VILPA) are bursts of incidental vigorous activity that occur during day-to-day activities outside of the exercise-domain. Vigorous intermittent lifestyle physical activity has shown promise in lowering risk of mortality and chronic disease. However, there is an absence of an empirically derived definition. Using physiological and effort-based metrics commonly used to define vigorous intensity, we investigated the minimum time needed to elicit physiological and perceived exertion responses to standardized activities of daily living. Methods: Seventy adults (age = 58.0 ± 9.6 yr; 35 female) completed 9 VILPA activities of daily living in a randomized order, which included fast walking, fast incline walking, stair climbing, stationary cycling, and carrying external weight equal to 5% and 10% of body weight. Metabolic rate (by continuous indirect calorimetry), heart rate (telemetry) and perceived effort (Borg Scale) were measured during exercise. Time to reach VILPA was assessed using %V̇O2max, %HRmax, and rating of perceived exertion thresholds. Results: The mean time to elicit VILPA ranged from 65 to 95 s (mean ± sd = 76.7 ± 3.8 s) for %V̇O2max, 68 to 105 s (mean ± sd = 82.8 ± 6.8 s) for %HRmax, and 20 to 60 s (mean ± sd = 44.6 ± 6.7 s) for rating of perceived exertion. For each of the three indices, there was no difference in the time to elicit VILPA responses by sex or age (P > 0.08), and times were also consistent between activities of daily living tasks. For example, for females and males, the average time to elicit vigorous responses while walking on a flat surface was 85.8 s (±16.9 s) and 80 s (±13.9 s), respectively, and for stair climbing while carrying 10% of body weight the duration was 78.4 s (±17.6 s) and 76.9 (±17.7 s). Conclusions: When participants undertook activities of daily living, VILPA elicited a physiological response at an average of 77 to 83 s for %V̇O2max and %HRmax, and 45 s for perceived exertion. The absence of a difference in the time to reach VILPA between sex and age suggests that a consistent behavioral VILPA translation can be used in interventions and population-based studies designed to assess the health effects of incidental physical activity. [ABSTRACT FROM AUTHOR]

Purpose: Given the rising burden of heart failure (HF), stratification of patients at increased risk for adverse events is critical. We aimed to compare the predictive value of various maximal and submaximal cardiopulmonary exercise test (CPET) variables for adverse events in patients with HF. Methods: A total of 237 patients with HF (66 (58–73) yr, 30% women, 70% HF with reduced ejection fraction) completed a CPET and had 5 yr of follow-up. Baseline characteristics and clinical outcomes (all-cause mortality, major adverse cardiovascular events, and cardiovascular-related hospitalization) were extracted from electronic patient files. Receiver operating characteristics curves for maximal (e.g., peak V̇O2) and submaximal CPET variables (e.g., VE/V̇CO2 slope, cardiorespiratory optimal point (COP), V̇O2 at anaerobic threshold) were compared using the Akaike Information Criterion (AIC) method, whereas their calibration was assessed. Results: One hundred three participants (43%) reached the composite endpoint, and 55 (23%) died. Percent predicted peak V̇O2 was the best predictor for adverse outcomes (AIC: 302.6) followed by COP (AIC: 304.3) and relative peak V̇O2 (mL·(kg·min)−1, AIC: 304.4). Relative peak V̇O2 (AIC: 217.1) and COP (AIC: 224.4) were also among the three best predictors for mortality, together with absolute peak V̇O2 (mL·min−1, AIC: 220.5). A good calibration between observed and predicted event rate was observed for these variables. Conclusions: Percent predicated and relative peak V̇O2 had the best predictive accuracy for adverse events and mortality, but the submaximal COP had a noninferior predictive accuracy for adverse events in patients with HF. These findings highlight the potential of submaximal exercise testing in patients with HF. [ABSTRACT FROM AUTHOR]

Purpose: Body cooling during and after exercise stimulates energy intake (EI). Cooling vests can also reasonably decrease body temperature under various sport occasions. This study examined the acute effects of wearing a cooling vest on EI and appetite after exercise and rest. Methods: Fifteen healthy young men underwent four trials randomly in a thermoneutral room (~24°C, ~40% humidity). In two exercise trials, participants performed a 60-min run at 75% of maximum oxygen uptake and wore a cooling vest (ExC) or thermoneutral vest (ExN) from 1030 to 1130 h. In two resting trials, participants rested for 60 min and wore a cooling vest (RC) or a thermoneutral vest (RN) from 1030 to 1130 h. From 1130 h, participants consumed a buffet meal until satiety. EI was calculated from the buffet meal. Skin and rectal temperatures were assessed between 0930 and 1130 h. Results: EI was significantly higher in the ExC trial (1740 ± 642 kcal) than in the ExN trial (1584 ± 604 kcal) and higher in the RC trial (1879 ± 806 kcal) than in the RN trial (1726 ± 806 kcal). Hot food consumption was significantly higher in the ExC trial than in the ExN trial and higher in the RC trial than in the RN trial. Subjective hunger was significantly higher in the ExC trial than in the ExN trial. Lower rectal temperatures were associated with higher relative EI (β = −8.871, P < 0.001). Conclusions: Wearing a cooling vest increased EI after exercise or rest and increased subjective appetite only after exercise. Increased EI may result from a preference for hot foods altered by a cooling vest. [ABSTRACT FROM AUTHOR]

Aim: In most vertebrates, oxygen deprivation and subsequent re‐oxygenation are associated with mitochondrial impairment and excess production of reactive oxygen species (ROS) like hydrogen peroxide (H2O2). This in turn triggers a cascade of cell‐damaging events in a temperature‐dependent manner. The crucian carp (Carassius carassius) is one of few vertebrates that survives months without oxygen at cold temperatures and overcomes oxidative damage during re‐oxygenation periods. Mitochondria of this anoxia‐tolerant species therefore serve as an excellent model in translational research to study adaptation and resilience to low oxygen conditions and thermal variability. Methods: Here, we used high‐resolution respirometry on isolated mitochondria from hearts of crucian carp and the anoxia‐intolerant mouse (Mus musculus), at 37 and 8°C; two temperatures relevant for transplantation medicine (i.e., graft preservation and subsequent rewarming). Results: We find: (1) a striking difference in H2O2 release between the two species at 37°C despite comparable mitochondrial efficiency and capacity, (2) a massive H2O2 release after inhibition of complex V in mouse at 37°C that is absent in crucian carp, and prevented in mouse by incubation at 8°C or uncoupling with a protonophore at 37°C, and (3) indications that differences in mitochondrial complex I and II capacity and thermal sensitivity influence the release of mitochondrial H2O2 relative to respiration. Conclusion: Our findings provide comparative insights into a spectrum of mitochondrial adaptations in vertebrates and the importance of thermal variability. Furthermore, the species‐ and temperature‐related changes associated with mitochondria highlighted in this study may help identify mitochondria‐based targets for translational medicine. [ABSTRACT FROM AUTHOR]

In this paper, a novel chessboard-like of metasurface based on two kinds of unit cell, using Vanadium dioxide (VO2) is proposed, designed, and demonstrated for radar cross-section (RCS) reduction. By accurately designing the geometric parameters of two units, the $ 180^{\circ}\pm 37^{\circ} $ 180 ∘ ± 37 ∘ reflection phase difference between the reflected waves can be obtained over a broadband region, thereby causing the interference cancellation and leading to the RCS reduction. In addition, the utilization of VO2 enables this metasurface to realize the reconfiguration of the working band while under different temperature conditions. Based on the above points, simulation results show that the proposed metasurface is provided with a −10 dB RCS reduction in 6.40–7.23 GHz and 14.97–23.97 GHz at a low-temperature state (300 K), and can be shifted to 7.10–14.13 GHz and 24.10–25.87 GHz at a high-temperature state (350 K), actualizing full coverage of the working frequency band from 6.40–25.87 GHz. Besides, the influences brought by different periodic arrangements of the unit cell and dielectric layer thickness on the reduction of RCS are also discussed in detail. [ABSTRACT FROM AUTHOR]

Common tenrecs (Tenrec ecaudatus) are fossorial mammals that use burrows during both active and hibernating seasons in Madagascar and its neighboring islands. Prevailing thought was that tenrecs hibernate for 8–9 months individually, but 13 tenrecs were removed from the same sealed burrow 1 m deep from the surface. Such group hibernation in sealed burrows presumably creates a hypoxic and/or hypercapnic environment and suggests that this placental mammal may have an increased tolerance to hypoxia and hypercapnia. Higher tolerances to hypoxia and hypercapnia have been documented for other mammals capable of hibernation and to determine if this is the case for tenrecs, we exposed them to acute hypoxia (4 h of 16 or 7% O2), progressive hypoxia (2 h of 16, 10 and 4% O2), or progressive hypercapnia (2 h of 2, 5 and 10% CO2) at cold (16 °C) or warm (28 °C) ambient temperatures (Ta). Oxygen equilibrium curves were also constructed on the whole blood of tenrecs at 10, 25, and 37 °C to determine if hemoglobin (Hb)-O2 affinity contributes to hypoxia tolerance. In animals held at 16 °C, normoxic and normocapnic levels of oxygen consumption rate ( V ˙ O 2 ), body temperature (Tb), and heart rate (HR) were highly variable between individuals. This inter-individual variation was greatly reduced in animals held at 28 °C for oxygen consumption rate and body temperature. Both hypoxia (acute and progressive) and progressive hypercapnia led to decreases in V ˙ O 2 as well as the variation in V ˙ O 2 between animals held at 16 °C. The fall in oxygen consumption rate in 7% O2 independent of changes in body temperature in tenrecs held at 16 °C is unique and not consistent with the typical hypoxic metabolic response seen in other hibernating species that depends on concomitant falls in Tb. In animals held at 28 °C, exposure to O2 levels as low as 4% and CO2 levels as high as 10% had no significant effect on V ˙ O 2 , HR, or Tb, indicative of high tolerance to both hypoxia and hypercapnia. High variation in heart rate remained between individuals in all gas compositions and at all temperatures. Tenrec Hb–O2 affinity was similar to other homeothermic placental mammals and likely does not contribute to the increased hypoxia tolerance. Ultimately, our results suggest changes in Ta dictate physiological responses to hypoxia or hypercapnia in tenrecs, responses more characteristic of reptiles than of most placental mammals. Given that numerous anatomical and physiological characteristics of tenrecs suggest that they may be representative of an ancestral placental mammal, our findings suggest the typical hypoxic metabolic response evolved later in mammalian evolution. [ABSTRACT FROM AUTHOR]

Many flatfish species are partially euryhaline, such as the Pacific sanddab which spawn and feed in highly dynamic estuaries ranging from seawater to near freshwater. With the rapid increase in saltwater invasion of freshwater habitats, it is very likely that in these estuaries, flatfish will be exposed to increasing levels of dissolved organic carbon (DOC) of freshwater origin at a range of salinities. As salinity fluctuations often coincide with changes in DOC concentration, two natural freshwater DOCs [Luther Marsh (LM, allochthonous) and Lake Ontario (LO, autochthonous) were investigated at salinities of 30 and 7.5 ppt. Optical characterization of the two natural DOC sources indicate salinity-dependent differences in their physicochemistry. LO and LM DOCs, as well as three model compounds [tannic acid (TA), sodium dodecyl sulfate (SDS) and bovine serum albumin (BSA)] representing key chemical moieties of DOC, were used to evaluate physiological effects on sanddabs. In the absence of added DOC, an acute decrease in salinity resulted in an increase in diffusive water flux (a proxy for transcellular water permeability), ammonia excretion and a change in TEP from positive (inside) to negative (inside). The effects of DOC (10 mg C L-1) were salinity and source-dependent, with generally more pronounced effects at 30 than 7.5 ppt, and greater potency of LM relative to LO. Both LM DOC and SDS increased diffusive water flux at 30 ppt but only SDS had an effect at 7.5 ppt. TA decreased ammonia excretion at 7.5 ppt. LO DOC decreased urea-N excretion at both salinities whereas the stimulatory effect of BSA occurred only at 30 ppt. Likewise, the effects of LM DOC and BSA to reduce TEP were present at 30 ppt but not 7.5 ppt. None of the treatments affected oxygen consumption rates. Our results demonstrate that DOCs and salinity interact to alter key physiological processes in marine flatfish, reflecting changes in both gill function and the physicochemistry of DOCs between 30 and 7.5 ppt. [ABSTRACT FROM AUTHOR]

An individual's energetic demands and hence metabolic rate can strongly change during adolescence, a phase characterized by profound morphological, physiological, and endocrine changes. Glucocorticoid hormones (e.g. cortisol) are released in response to hypothalamic–pituitary–adrenal–axis activity, modulate several metabolic processes, and can also be linked to increased metabolic rate. In domestic guinea pigs (Cavia aperea f. porcellus) housed in same-sex groups, cortisol concentrations increase during adolescence in males but remain stable in females, which was suggested to be related to different energetic demands by age. We therefore measured metabolic rate through oxygen (O2) consumption over 2.5 h in male and female guinea pigs housed in same-sex groups during adolescence at ages of 60, 120, and 180 days, which was paralleled by analyses of saliva cortisol concentrations before and after the measurement. The statistical analyses involved whole body metabolic rate (ml O2/h), body mass-corrected metabolic rate (ml O2/h/kg), and body mass-independent metabolic rate (ml O2/h statistically corrected for body mass). We found increasing cortisol concentrations with age in males only, but none of the three metabolic rate analyses revealed a sex difference by age. On the individual level, repeatability across ages was found in metabolic rate as well as in body mass and cortisol concentrations after the measurement, but not in "basal" cortisol concentrations. Our results suggest no sex-specific changes in metabolic rate and hence equal energetic demands in male and female guinea pigs during adolescence. Moreover, metabolic rate clearly represents a highly stable physiological trait already early in a guinea pig's life irrespective of rather fluctuating cortisol concentrations. [ABSTRACT FROM AUTHOR]

Neurodegenerative diseases such as Alzheimer's disease (AD), Parkinson's disease (PD), and Huntington's disease (HD) have become a major global health burden, but the detailed pathogeneses of neurodegenerative diseases are still unknown, and current treatments are mainly aimed at controlling symptoms; there are no curative treatments for neurodegenerative diseases or treatments for the progressive cognitive, behavioral, and functional impairments that they cause. Studies have shown that some plant extracts with pungent flavor components have a certain neuroprotective effect in neurodegenerative diseases, and their mechanisms mainly involve inhibiting neuronal apoptosis, promoting neuronal regeneration, reducing mitochondrial degeneration, and reducing the production of oxides such as reactive oxygen species in cells, which are of great significance for exploring the treatment of neurodegenerative diseases. In this review, we searched the PubMed database for relevant literature collected in the past 15 years. Finally, we summarized the protective effects of pungent flavor components such as capsaicin, piperine, curcumin, cannabinoids, allicin, and nicotine on the nervous system, focusing on the molecular mechanisms and signaling pathways that they activate. In addition, we also compiled and summarized the laboratory experiments, preclinical experiments, and effects of various pungent flavor components in neurodegenerative diseases. The goal is to further explore their potential as effective drugs for the treatment of neurodegenerative diseases and provide new ideas for further research on the specific protective mechanisms of these substances for the treatment of neurodegenerative diseases and the targets of drug action in the future. [ABSTRACT FROM AUTHOR]

Background: Muscle biopsy, the gold standard for assessing muscle aerobic capacity, is an invasive procedure. Noninvasive alternatives, such as 31-phosphorus magnetic resonance spectroscopy (31P-MRS) and near-infrared spectroscopy (NIRS), provide valuable insights, with NIRS providing superior time resolution and ease of use compared with 31P-MRS. Objectives: This study aimed to evaluate muscle metabolism using a 6 s muscle contraction phase with electrical muscle stimulation (EMS) and to assess the impact of EMS on exercise performance under hyperbaric conditions with elevated oxygen pressure. Methods: This study included nine male participants (21 ± 2 years) who underwent 5 min of EMS on the forearm flexor muscle group, with muscle oxygen dynamics assessed using NIRS. For statistical analysis, the mean values between groups were assessed using paired t-tests, and associations were evaluated using Pearson's correlation coefficient. Results: Spontaneous blood flow interruption during EMS-induced muscle activity indicated the potential for assessing muscle metabolism without disrupting external blood flow. A significant negative correlation was observed between oxygen consumption and changes in oxygenated hemoglobin levels during muscle activity under hyperbaric conditions. Conclusions: This study demonstrates that skeletal muscle metabolism can be measured using a brief 6 s quantitative EMS. Furthermore, hyperbaric exercise appears to enhance aerobic capacity by increasing the rate and availability of oxygen consumption during exercise. [ABSTRACT FROM AUTHOR]

Background: Although numerous attempts to demonstrate inter-individual differences in trainability across various outcomes have been unsuccessful, the investigation of maximal oxygen consumption (VO2max) trainability warrants further study. Objective: Our objective was to conduct the first systematic review and meta-analysis to evaluate inter-individual differences in VO2max trainability across aerobic exercise training protocols utilizing non-exercising comparator groups. Methods: We conducted a literature search across three databases: EMBASE, PubMed and SCOPUS. The search strategy incorporated two main concepts: aerobic exercise training and VO2max. Studies were included if they used human participants, employed standardized and supervised exercise training, reported absolute or relative VO2max, included a non-exercise comparator group, reported VO2max change scores for non-exercise and exercise groups and provided the standard deviation (SD) of change for all groups. We calculated the SD of individual response (SDIR) to estimate the presence of inter-individual differences in trainability across all studies. Results: The literature search generated 32,968 studies, 24 of which were included in the final analysis. Our findings indicated that (1) the majority of variation in observed change scores following an intervention is due to measurement error, (2) calculating SDIR within a single study would not yield sufficient accuracy of SDIR due to generally small sample sizes and (3) meta-analysis of SD IR 2 across studies does not provide strong evidence for a positive value. Conclusion: Overall, our meta-analysis demonstrated that there is not strong evidence supporting the existence of VO2max trainability across single interventions. As such, it appears unlikely that clinically relevant predictors of VO2max response will be discovered. Registration can be found online (https://doi.org/10.17605/OSF.IO/X9VU3). [ABSTRACT FROM AUTHOR]

At a point during the latter third of an incremental exercise protocol, ventilation begins to exceed the rate of clearance of carbon dioxide (CO2) at the lungs ( V ˙ CO2). The onset of this hyperventilation, which is confirmed by a fall from a period of stability in end-tidal and arterial CO2 tensions (PCO2), is referred to as the respiratory compensation point (RCP). The mechanisms that contribute to the RCP remain debated as does its surrogacy for the maximal metabolic steady state of constant-power exercise (i.e., the highest work rate associated with maintenance of physiological steady state). The objective of this current opinion is to summarize the original research contributions that support and refute the hypotheses that: (i) the RCP represents a rapid, peripheral chemoreceptor-mediated reflex response engaged when the metabolic rate at which the buffering systems can no longer constrain the rise in hydrogen ions ([H+]) associated with rising lactate concentration and metabolic CO2 production is surpassed; and (ii) the metabolic rate at which this occurs is equivalent to the maximal metabolic steady state of constant power exercise. In doing so, we will shed light on potential mechanisms contributing to the RCP, attempt to reconcile disparate findings, make a case for its adoption for exercise intensity stratification and propose strategies for the use of RCP in aerobic exercise prescription. [ABSTRACT FROM AUTHOR]

Background: A novel sodium bicarbonate (SB) product has come to market named the "Bicarb System" (M-SB; Maurten AB, Gothenburg, Sweden). It claims to minimise gastrointestinal (GI) discomfort whilst still improving exercise performance. Aim: To investigate the effects of M-SB ingestion on repeated 4 km cycling time trials (TT1 and TT2) in well-trained male cyclists. Methods: The study recruited ten well-trained cyclists (maximal oxygen uptake ( V ˙ O 2 max ): 67 ± 4 ml kg−1 min−1 BM; peak power output (PPO) at V ˙ O 2 max : 423 ± 21 W) to take part in this randomised, crossover and double-blinded study. Following one visit to determine V ˙ O 2 max , participants completed a second visit to identify individual time to peak blood bicarbonate (HCO3−) (ITTP) in a rested state. Visit three was a familiarisation trial mimicking the experimental procedures. Visits four to seven consisted of completing 2 × 4 km cycling TTs separated by 45 min passive recovery, following one of either: 0.3 g kg−1 BM M-SB, 0.21 g kg−1 BM sodium chloride (placebo; PLA) in vegetarian capsules (size 00), or a control trial (CON). Supplements (M-SB or placebo) were ingested pre-exercise at their respective ITTP. Results: Performance in TT1 was faster in the M-SB condition compared with TT1 in CON (− 5.1 s; p = 0.004) and PLA (− 3.5 s; p < 0.001). In TT2, performance was also significantly faster in the M-SB condition compared with CON (− 4.4 s; p = 0.018) or PLA (− 4.1 s; p = 0.002). Total aggregated GI symptoms were generally low and not significantly different between PLA and the M-SB conditions for a range of symptoms. Conclusions: The ingestion of M-SB improves repeated 4 km cycling TT performance and the recovery of acid–base balance between bouts, whilst causing minimal GI discomfort. [ABSTRACT FROM AUTHOR]

Hibernating mammals experience severe hemodynamic changes over the torpor–arousal cycle, with oxygen consumption reaching peaks during the early stage of torpor to re-enter arousal. Melatonin (MT) can improve mitochondrial function and reduce oxidative stress and inflammation. However, the regulatory mechanisms of MT action on the vascular protective function of hibernators are still unclear. Morphology, hemodynamic, mitochondrial oxidative stress, and inflammatory factors of the carotid artery were assessed in ground squirrels who were sampled during summer active (SA), late torpor (LT), and interbout arousal (IBA) conditions. Changes were assessed by methods including hematoxylin and eosin staining, color Doppler ultrasound, ELISA, Western blots, and qPCR. Changes in arterial blood and serum melatonin were also measured by blood gas analyzer and ELISA, whereas mitochondrial oxidative stress and inflammation factors of primary vascular smooth muscle cells (VSMCs) were assessed by qPCR. (1) Intima-media carotid thickness, peak systolic velocity (PSV), end diastolic blood flow velocity (EDV), maximal blood flow rate (Vmax) and pulsatility index (PI) were significantly decreased in the LT group as compared with the SA group, whereas there were no difference between the SA and IBA groups. (2) PO2, oxygen saturation, hematocrit and PCO2 in the arterial blood were significantly increased, and pH was significantly decreased in the LT group as compared with the SA and IBA groups. (3) The serum melatonin concentration was significantly increased in the LT group as compared with the SA and IBA groups. (4) MT treatment significantly reduced the elevated levels of LONP1, NF-κB, NLRP3 and IL-6 mRNA expression of VSMCs under hypoxic conditions. (5) Protein expression of HSP60 and LONP1 in the carotid artery were significantly reduced in the LT and IBA groups as compared with the SA group. (6) The proinflammatory factors IL-1β, IL-6, and TNF-α were reduced in the carotid artery of the LT group as compared with the SA and IBA groups. The carotid artery experiences no oxidative stress or inflammatory response during the torpor–arousal cycle. In addition, melatonin accumulates during torpor and alleviates oxidative stress and inflammatory responses caused by hypoxia in vitro in VSMCs from ground squirrels. [ABSTRACT FROM AUTHOR]

Aims: Cardiopulmonary exercise testing (CPET) combined with exercise echocardiography (CPETecho) allows simultaneous assessments of cardiac, pulmonary, and ventilation in heart failure (HF) with preserved ejection fraction (HFpEF). This study sought to determine whether simultaneous assessment of CPET variables could provide additive predictive value over exercise stress echocardiography in patients with dyspnoea. Methods and results: CPETecho was performed in 443 patients with suspected HFpEF (240 HFpEF and 203 controls without HF). Patients with HFpEF were divided based on peak oxygen consumption (VO2, ≥10 or <10 ml/min/kg) or the slope of minute ventilation to carbon dioxide production (VE vs. VCO2 slope ≥45.0 or <45.0). The primary endpoint was defined as a composite of all‐cause mortality, HF hospitalization, unplanned hospital visits requiring intravenous diuretics, or intensification of oral diuretics. During a median follow‐up of 399 days, the composite outcome occurred in 57 patients. E/e' ratio during peak exercise was associated with adverse outcomes. Patients with HFpEF and lower peak VO2 had increased risks of the composite event (hazard ratio [HR] 5.05, 95% confidence interval [CI] 2.65–9.62, p < 0.0001 vs. controls; HR 3.14, 95% CI 1.69–5.84, p = 0.0003 vs. HFpEF with higher peak VO2). Elevated VE versus VCO2 slope was also associated with adverse events in HFpEF. The addition of either the presence of abnormal peak VO2 or VE versus VCO2 slope increased the predictive ability over the model based on age, sex, atrial fibrillation, left atrial volume index, and exercise E/e' (p < 0.05). Conclusion: These data provide new insights into the role of CPETecho in patients with HFpEF. [ABSTRACT FROM AUTHOR]