Constant Cycle Research Articles

Solvent- and Catalyst-Free Environmentally Benign High Hydrostatic Pressure-Assisted Synthesis of Bioactive Hydrazones and the Evaluation of Their Stability Under Various Storage Conditions

Our group has seen great promise in using substituted diaryl-hydrazones to alleviate oxidative stress in preeclampsia. Specifically, fluorinated diaryl-hydrazones have shown great efficacy, confirmed via antioxidant assays and animal trials using pregnant mice. In addition to efficient antioxidant properties, these diaryl-hydrazones are also considered non-toxic. While the synthesis of these compounds is relatively simple, it commonly utilizes undesirable solvents and glacial acetic acid as the catalyst; additional solvents are needed for the isolation of the desired products, which negatively affects the green synthesis of the hydrazones. To combat this possible industrial roadblock, we have begun incorporating the use of hydrostatic high pressure (HHP) in the synthesis. The use of HHP allowed us to synthesize substituted diaryl-hydrazones in a 1:1 molar ratio without the need for solvents or acid catalysts. The optimized procedure can produce nearly quantitative yields, leading to an easier isolation of the products. Different HHP methodologies, such as constant high-pressure treatment and cycling (with different number of cycles, holding and decompression times) were applied and cycling was observed to be the most efficient activation for the majority of the reactions. Stability experiments were also conducted with one of the products and observed that although the solid-state storage does not alter the hydrazone, storing it in various solvents may significantly decrease the concentration of the active component which should be considered when performing the biochemical/biological assays.

Middle cerebral artery blood velocity and end-tidal carbon dioxide responses to moderate intensity cycling in children, adolescents, and adults.

This study investigated the middle cerebral artery blood velocity (MCAv) response to constant work-rate moderate-intensity cycling exercise in 21 children (9.3 ± 0.8 yr), 17 adolescents (12.3 ± 0.4 yr), and 20 young adults (23.6 ± 2.4 yr). Participants completed an incremental ramp test to exhaustion on a cycle ergometer to determine maximal oxygen uptake and gas exchange threshold (GET) before completing three 6-min transitions at a moderate intensity (90% GET) on separate visits. On each visit, bilateral MCAv was measured by transcranial Doppler ultrasonography and breath-by-breath end-tidal carbon dioxide ([Formula: see text]) via a metabolic cart. Data were ensemble-averaged for each participant and analyzed using a monoexponential model. Absolute MCAv was significantly higher throughout exercise in children and adolescents compared with adults (P < 0.001). Children had a significantly lower relative increase in MCAv from baseline (∼12%) compared with adolescents (∼20%) and adults (∼18%, P < 0.040). All adolescents and adults had a monoexponential rise in MCAv and [Formula: see text], but this was observed in only eight children. Children and adolescents had a significantly faster MCAv time constant (τ, 12 ± 6 and 14 ± 8 s, respectively) compared with adults (27 ± 9 s, P < 0.001). MCAv τ was positively associated with faster [Formula: see text] τ in adolescents (r = 0.70, P = 0.002) but not in children (r = -0.20, P = 0.640). Time- and amplitude-based response parameters of MCAv kinetics were significantly associated with [Formula: see text] kinetics in adults (r = 0.50-0.74, P ≤ 0.025), but not in children (r = -0.19 to -0.48, P > 0.227). These findings suggest that the transition from childhood to adulthood impacts the MCAv response to exercise and the relationships between [Formula: see text] and MCAv kinetics during exercise.NEW & NOTEWORTHY This is the first study to find that children have smaller increases in Δ%MCAv (∼12%) during moderate-intensity exercise compared with adolescents and adults (∼18%-20%). Furthermore, MCAv kinetics were significantly faster in children and adolescents, compared with adults. MCAv kinetic responses were significantly and positively associated with [Formula: see text] kinetics in adults, but not in children. These novel data also suggest that the regulatory role of [Formula: see text] on MCAv during exercise begins to strengthen during adolescence.

Stiffness degradation and mechanical behavior of microfiber-modified high-toughness recycled aggregate concrete under constant load cycling

The mechanical properties of High-Toughness Recycled Aggregate Concrete (HTRAC) were investigated in this study as an innovative and environmentally friendly construction material, along with its potential applications in structural stability. Small-scale specimens with six levels of micro-steel fiber content were made, and a series of cyclic tests with constant loads were carried out. Using In-Situ 4D CT technology, the damage characteristics of the microstructure of HTRAC and the reinforcing effects of fibers on key mechanical parameters (peak stress, peak strain, ultimate strain, post-peak modulus, and toughness indicators) were analyzed. A comprehensive fiber reinforcing factor calculation model was proposed to assess its contribution to strength, deformability, and toughness, and the correlation between the number of cyclic loadings and stiffness degradation was also quantified. it is confirmed that HTRAC exhibits a significant advantage in toughness compared to traditional recycled aggregate concrete (RAC). The findings of this study provide crucial technical support for the further development and application of HTRAC, indicating its promising prospects in the field of sustainable construction materials

Lignin-Based N-Carbon Dots Anchoring NiCo2S4/Graphene Hydrogel Exhibits Excellent Performance as Anodes for Hybrid Supercapacitor.

A NiCo2S4/N-CDs/RGO ternary composite hydrogel was prepared via a one-step hydrothermal method, utilizing lignin-based nitrogen-doped carbon dots as a bridge connecting NiCo2S4 and graphene. The specific capacitance of NiCo2S4/N-CDs/RGO significantly outperforms that of the GH and NiCo2S4/RGO electrodes, achieving 1050 F g-1. The 3D mesh porous hydrogel structure mitigates NiCo2S4 nanoparticle aggregation, providing a larger specific surface area for enhanced charge storage. The abundant functional groups of N-CDs interact with Ni (II) and Co (III) cations, favoring NiCo2S4 particle synthesis. Additionally, an assembled solid-state asymmetric supercapacitor employing NiCo2S4/N-CDs/RGO as the positive electrode exhibited excellent energy density (68.4 Wh kg-1) and cycle stability (82% capacitance retention after 10,000 constant current charge-discharge cycles).

Effects of inhaled beclometasone dipropionate/formoterol fumarate/glycopyrronium vs. beclometasone dipropionate/formoterol fumarate and placebo on lung hyperinflation and exercise endurance in chronic obstructive pulmonary disease: a randomised controlled trial

BackgroundThe single-inhaler triple combination of beclometasone dipropionate, formoterol fumarate, and glycopyrronium (BDP/FF/G) is available for maintenance therapy of chronic obstructive pulmonary disease (COPD). Cardinal features of COPD are lung hyperinflation and reduced exercise capacity. TRIFORCE aimed to evaluate the effect of BDP/FF/G on lung hyperinflation and exercise capacity in patients with COPD.MethodsThis double-blind, randomised, active- and placebo-controlled, crossover study recruited adults with COPD aged ≥ 40 years, who were hyperinflated and symptomatic, and were receiving mono- or dual inhaled maintenance COPD therapy. In the three treatment periods, patients were randomised to receive BDP/FF/G, BDP/FF, or placebo, each for 3 weeks, with a 7–10-day washout between treatment periods. Assessments included slow inspiratory spirometry (for resting inspiratory capacity [IC]) and constant work-rate cycle ergometry (for dynamic IC and exercise endurance time). The primary objective was to compare BDP/FF/G and BDP/FF vs. placebo for resting IC at Week 3. Key secondary objectives were to compare BDP/FF/G and BDP/FF vs. placebo for dynamic IC and exercise endurance time during constant work rate cycle ergometry at Week 3.ResultsOf 106 patients randomised, 95 completed the study. Resting IC adjusted mean differences vs. placebo were 315 and 223 mL for BDP/FF/G and BDP/FF, respectively (p < 0.001 for both). Adjusted mean differences vs. placebo for the key secondary endpoints were: 245 mL for dynamic IC (p < 0.001) and 69.2 s for exercise endurance time (nominal p < 0.001) with BDP/FF/G, and 96 mL (p = 0.053) and 70.1 s (nominal p < 0.001) with BDP/FF. Differences between BDP/FF/G and BDP/FF for resting and dynamic IC were 92 and 149 mL (p < 0.01 for both). All three treatments were generally well tolerated, with 27.3%, 25.3% and 19.0% of patients reporting adverse events with BDP/FF/G, BDP/FF and placebo, respectively, all mild or moderate.ConclusionsIn patients with COPD, BDP/FF/G provided significant and clinically relevant improvements vs. placebo and BDP/FF in static and dynamic hyperinflation, with an improvement vs. placebo in exercise endurance.Trial registrationClinicalTrials.gov (NCT05097014), registered 27th October 2021.

Synergistic Dual Electrolyte System of LATP and In‐ Situ Solod‐State PDOL System and its Improvement on the Performance of NCM811 Batteries

Abstract1,3‐Dioxolane (DOL) can undergo in‐situ polymerization in batteries to form solid‐state organic electrolyte PDOL. When applied to NCM811||Li battery system, PDOL electrolyte helps optimize the contact and interface stability between electrolyte and electrodes. This study explores the effects of PDOL with PE separators coated with Li1.3Al0.3Ti1.7(PO4)3(LATP) on the performance of NCM811||Li batteries. 2,2,2‐trifluoroethyl phosphite (DETFPi), was mixed with DOL at a 1 : 35 mass ratio. Then, LiBF4 was used to initiate in‐situ polymerization and thereby obtained DETFPi‐PDOL electrolyte after 24 h at room temperature. The composite electrolyte exhibits enhanced ion conductivity (1.59×10−4 S cm−1), high lithium ion transference number (0.78), wide electrochemical stability window (4.53 V), and high critical current density (2.2 mA cm−2). Li||PDOL@LATP||Li battery shows extremely low overpotential (35 mV) after a constant current stable cycle of 500 h at 1.0 mA cm−2. After 500 cycles at 1 C, the remaining capacity is 153.9 mAh g−1 with a capacity retention of 82.1 % in NCM811||PDOL@LATP||Li batteries. This indicates that the LATP coating on the surface of the PE separator plays an important role in optimizing the performance of DETFPI‐PDOL electrolyte batteries. LATP and DETFPI‐PDOL are effective in improving the cycling stability, rate performance, and interface state of NCM811 batteries.

Acute partial sleep deprivation attenuates blood pressure responses to cycling exercise.

Exaggerated blood pressure (BP) responses during exercise are independently associated with future development of hypertension. Partial sleep deprivation (PSD) can increase 24-h ambulatory BP, but the effects on exercise BP are unclear. We hypothesized that acute PSD would augment the BP response to constant load cycling exercise and a 20-min time trial. Twenty-two healthy adults (22 ± 3 yr old; 13 males; V̇o2peak, 43.6 ± 8.2 mL·kg-1·min-1) completed a randomized crossover trial in which they either slept normally (normal sleep-wake schedule for each participant) or sleep was partially deprived (early awakening, 40% of normal sleep duration). Each participant completed a 12-min warm-up consisting of two 6-min steps (step 1, 62 ± 25 W; step 2, 137 ± 60 W) followed by a 20-min time trial on a cycle ergometer. PSD did not alter power output during the 20-min time trial [(control vs. PSD) 170 ± 68 vs. 168 ± 68 W, P = 0.65]. Systolic BP did not differ during step 1 of the warm-up (141 ± 15 vs. 137 ± 12 mmHg, P = 0.39) but was lower following PSD during step 2 (165 ± 21 vs. 159 ± 22 mmHg, P = 0.004) and the 20-min time trial (171 ± 20 vs. 164 ± 23 mmHg, P < 0.001). These results were maintained when peak oxygen uptake (V̇o2peak) was included as a covariate. Systolic BP responses were modulated by sex (time × visit × sex interaction P = 0.03), with attenuated systolic BP during the warm-up and the 20-min time trial in males but not in females. In contrast to our hypothesis, acute PSD attenuates systolic BP responses during constant load and 20-min time trial cycling exercise; however, these observations appear to be primarily driven by changes in males.NEW & NOTEWORTHY A single night of partial sleep deprivation (PSD) can increase ambulatory blood pressure (BP) the following day. Despite this phenomenon, the present study found that acute PSD attenuates systolic BP responses to both constant load cycling and a 20-min cycling time trial in young healthy adults. Interestingly, the attenuated systolic BP responses following PSD appeared to be modulated by sex such that attenuations were observed in males but not in females.

Defect-rich hard carbon designed by heteroatom escape assists sodium storage performance for sodium-ion batteries

Sodium-ion batteries (SIBs) avoids the use of expensive cobalt element, and the abundance of sodium element is high, so it shows great application potential, and the development of sodium-ion battery materials is of great value. Biomass precursors have the advantages of low cost and widely and sufficiently distributed resources, and embody the environmental concept of waste utilization, however, the poor reversible specific capacity and initial coulombic efficiency (ICE) of pristine corn stover-derived hard carbons (CSHCs) limit their practical application value. In this paper, we propose a method to increase the reversible specific capacity of hard carbon and maintain high ICE, introduce heteroatoms into graphene-like nanosheets at low carbonization temperature, then escape heteroatoms through high pyrolysis temperature, create defects in the graphene-like carbon layer and expand the (002) layer spacing. Density functional theory (DFT) calculations show that defects are beneficial to the adsorption of Na+ on graphene-like nanosheets, and Na+ have a lower diffusion barrier between layers rich in defects and extended (002) layer spacing. Compared with the conventional low pyrolysis temperature heteroatom doping process, the present method exhibits superior ICE. In the ester-based electrolyte, the modified hard carbon (D-CSHC) exhibits a superior specific capacity of 284.5 mAh/g and an ICE of 85.9 % as compared to the pristine corn stover-derived hard carbon (233.5 mAh/g, 72.7 %). In addition, the capacity retention rate was 92.6 % after 500 turns of constant current cycles at 0.15 A/g.

PSXIII-13 Evaluation of physiological functions and performance in laying hens in different housing systems

Abstract Egg production faces many challenges of economics, disease control and animal welfare concerns. Therefore, investigation of physiological characteristics in laying hens should be required for further discussion on such issues from a scientific point of view. In this study, we evaluated physiological functions and production parameters of hens raised in three different housing systems, conventional battery cage (CC), enriched cage (EC) and aviary system (AV). Lohmann Selected Leghorn Lite laying hens (n = 251) were used. At first, all the pullets were housed in CC. Then, a telemetric transmitter was implanted to randomly selected 18 hens on d 171 after birth to record electrocardiograms (ECGs), heart rate (HR), body temperature (BT) and locomotor activity (LA). Heart rate variability (HRV), which was analyzed using ECG, has been established as a suitable method for investigating autonomic nervous functions, and to assess stress and well-being of housing systems. On d 200 after birth, some of the hens were randomly selected and transferred to EC or AV (CC; n = 88, EC; n = 72, AV; n = 91), including hens implanted a transmitter (6 hens in each group). All parameters at 10 d before and 1 wk after the group division were compared. Egg laying rate (ELR), feed conversion ratio (FCR) and shell deformation were evaluated for egg production parameters. Hens were basically housed under the same management condition, and a constant light-dark cycle (light-on from 0300 to 1930 h). Feeding was conducted during light-phase, and water was supplied ad libitum. Statistical significance was defined as P &amp;lt; 0.05. Comparing the physiological parameter, HR during dark-phase and LA during light-phase after transferred to EC or AV were greater than those in CC. However, there was no significant difference in HR during light-phase or LA during dark-phase between CC and the other two groups. The high frequency (HF) power of HRV, which reflects parasympathetic nervous function, was high during the dark-phase (7.59 ± 1.56) and low during the light-phase (6.04 ± 0.78) in CC. This diurnal variation disappeared in EC or AV because the HF power during the dark-phase decreased. As for production, ELR, FCR and shell deformation were decreased after moved to AV, which were not found in other two groups after the group division. This study was conducted to clarify the effects of housing systems on the physiological functions and productivity of laying hens, and these results suggest that CC might provide hens with parasympathetic dominance with greater quality of rest in dark-phase, and AV causes the reduction of egg production. However, we cannot completely rule out the possibility that these results are influenced by movement to a different housing system. Therefore, further analysis should be performed to assess the relations between physiological functions, management and egg production.

Effect of the pulse frequency on the structure, mechanical and tribological properties of Ti-Al-Ta-N coatings deposited by HiPIMS

Columnar microstructure significantly deteriorates performance of Ti-Al-Ta-N coatings obtained by physical vapor deposition. The present work is focused on studying the possibility to hinder the growth of columnar grains in the Ti-Al-Ta-N coatings using short-pulse high-power impulse magnetron sputtering (HiPIMS). The change of the pulse length is carried out by varying the pulse frequency f from 0.5 to 10 kHz at a constant duty cycle of 10 %. This results in decreasing the pulse length from 200 to 10 μs. It is found that the pulse frequency affects the parameters of magnetron discharge and ion flux at the substrate. Short-pulse HiPIMS realized at higher pulse frequencies (2–10 kHz) provides an increase in the ion flux arriving at the substrate compared to the HiPIMS processes at lower frequencies (0.5 and 1 kHz). The increased ion flux bombarding the growing coatings leads to evolution of their microstructure from the open columnar structure observed at f < 2 kHz to the dense microstructure containing only small columnar fragments at f ≥ 2 kHz. The microstructure modification provides improved mechanical properties and wear resistance of the Ti-Al-Ta-N coatings obtained at f ≥ 2 kHz. The maximum hardness and wear resistance were found in the coating deposited at 5 kHz.

Permittivity enhancement of Al2O3/ZrO2 dielectrics with the incorporation of Pt nanoparticles

Al2O3/ZrO2 (A/Z) layers with embedded Pt nanoparticles (Pt-nps) at the interface of A/Z have been used to create a dielectric film with an enhanced permittivity. The Pt-nps and dielectrics are both grown by the atomic layer deposition process, which is complementary metal–oxide–semiconductor compatible. In order to control the thickness ratio of Pt-nps in the overall dielectrics more easily, the thickness of the ZrO2 layer is changed from 12 to 30 nm with a fixed thickness of 12 nm for Al2O3 and constant growth cycles of 70 for Pt-nps. The results show that the introduction of Pt-nps is beneficial to the enhancement of the dielectric permittivity. As the thickness of ZrO2 is 30 nm, the capacitance density increases from 2.5 to 5.1 fF/μm2 with the addition of Pt-nps, i.e., a doubling of the capacitance density achieved. Additionally, the leakage current at 2 V increases from 1.1 × 10−8 to 1.5 × 10−7 A/cm2. Furthermore, the dielectric breakdown field decreases from 5.4 to 2.7 MV/cm. The electric field distribution simulation and charging–discharging test imply that interfacial polarization is built at the interface of Pt-nps and the dielectric films, which contributes to the dielectric permittivity enhancement, and local electric field increasing in the affinity of Pt-nps gives rise to the deterioration of the leakage current and breakdown electric field.

Polymer Composite Electrolytes Membrane Consisted of Polyacrylonitrile Nanofibers Containing Lithium Salts: Improved Ion Conductive Characteristics and All‐Solid‐State Battery Performance

AbstractPolymer electrolyte membranes with superior lithium‐ion (Li+) conductivity and sufficient electrochemical stability are desired for all‐solid‐state lithium‐ion batteries (ASS‐LIBs). This paper reports novel polymer composite membranes consisting of polyacrylonitrile (PAN) nanofibers (Nfs) containing lithium salts. It is first revealed that the lithium salt addition increases polar surface groups on the PAN nanofibers. Subsequently, the lithium salts‐containing PAN nanofiber (PAN/Li Nf) composite membrane affects the matrix poly(ethylene oxide) (PEO)/lithium bis(trifluoromethyl sulfonylimide) (LiTFSI) electrolyte to increase the numbers of Li+ with high mobility. Consequently, the PAN/Li Nf composite membrane shows relatively good ion conductivity (σ = 9.0 × 10−5 S cm−1) and a considerably large Li+ transference number (tLi+ = 0.41) at 60 °C, compared to the PEO/LiTFSI membrane without nanofibers. The 6Li solid‐state NMR study supports that the PAN/Li Nf bearing abundant polar nitrile groups at their surface enhances Li+ diffusion in the PEO‐based electrolyte membranes. The galvanostatic constant current cycling tests reveal that the PAN/Li Nf composite membrane possesses good electrochemical and mechanical stabilities. The ASS‐LIB consisting of the PAN/Li Nf composite membrane shows significantly improved charge and discharge cycling performances, promising future all‐solid‐state batteries.

Combined Impact of Heart Rate Sensor Placements with Respiratory Rate and Minute Ventilation on Oxygen Uptake Prediction.

Oxygen uptake (V˙O2) is an essential metric for evaluating cardiopulmonary health and athletic performance, which can barely be directly measured. Heart rate (HR) is a prominent physiological indicator correlated with V˙O2 and is often used for indirect V˙O2 prediction. This study investigates the impact of HR placement on V˙O2 prediction accuracy by analyzing HR data combined with the respiratory rate (RESP) and minute ventilation (V˙E) from three anatomical locations: the chest; arm; and wrist. Twenty-eight healthy adults participated in incremental and constant workload cycling tests at various intensities. Data on V˙O2, RESP, V˙E, and HR were collected and used to develop a neural network model for V˙O2 prediction. The influence of HR position on prediction accuracy was assessed via Bland-Altman plots, and model performance was evaluated by mean absolute error (MAE), coefficient of determination (R2), and mean absolute percentage error (MAPE). Our findings indicate that HR combined with RESP and V˙E (V˙O2HR+RESP+V˙E) produces the most accurate V˙O2 predictions (MAE: 165 mL/min, R2: 0.87, MAPE: 15.91%). Notably, as exercise intensity increases, the accuracy of V˙O2 prediction decreases, particularly within high-intensity exercise. The substitution of HR with different anatomical sites significantly impacts V˙O2 prediction accuracy, with wrist placement showing a more profound effect compared to arm placement. In conclusion, this study underscores the importance of considering HR placement in V˙O2 prediction models, with RESP and V˙E serving as effective compensatory factors. These findings contribute to refining indirect V˙O2 estimation methods, enhancing their predictive capabilities across different exercise intensities and anatomical placements.

Beneficial Physiological and Metabolic Effects with Acute Intake of New Zealand Blackcurrant Extract during 4 h of Indoor Cycling in a Male Ironman Athlete: A Case Study.

New Zealand blackcurrant (NZBC) is known to alter exercise-induced physiological and metabolic responses with chronic (i.e., 7 days) dosing. We examined the effects of acute intake of New Zealand blackcurrant (NZBC) extract on 4 h indoor cycling-induced physiological and metabolic responses in a male amateur Ironman athlete (age: 49 years; BMI: 24.3 kg·m-2; V˙O2max: 58.6 mL·kg-1·min-1; maximal aerobic power: 400 W; history: 14 Ironman events in 16 years) three weeks before competition. Indirect calorimetry was used and heart rate was recorded at 30 min intervals during 4 h indoor (~22.4 °C, relative humidity: ~55%) constant power (165 W) cycling on a Trek Bontrager connected to a Kickr smart trainer. Blood lactate and rating of perceived exertion (RPE) were taken at 60 min intervals. Study was a single-blind placebo-controlled study with capsules (4 × 105 mg anthocyanins) taken 2 h before starting the 4 h of cycling. Water was allowed ad libitum with personalised consumption of gels [a total of eight with three with caffeine (100 mg)], two bananas and 8 × electrolyte capsules (each 250 mg sodium and 125 mg potassium) at personalised time-points. With NZBC extract (CurraNZ), during 4 h of cycling (mean of 8 measurements), minute ventilation was 8% lower than placebo. In addition, there was no difference for oxygen uptake, with carbon dioxide production found to be 4% lower with NZBC extract. With the NZBC extract, the ventilatory equivalents were lower for oxygen and carbon dioxide by 5.5% and 3.7%; heart rate was lower by 10 beats·min-1; lactate was 40% different with lower lactate at 2, 3 and 4 h; RPE was lower at 2, 3 and 4 h; and carbohydrate oxidation was 11% lower. With NZBC extract, there was a trend for fat oxidation to be higher by 13% (p = 0.096), with the respiratory exchange ratio being lower by 0.02 units. Acute intake of New Zealand blackcurrant extract (420 mg anthocyanins) provided beneficial physiological and metabolic responses during 4 h of indoor constant power cycling in a male amateur Ironman athlete 3 weeks before a competition. Future work is required to address whether acute and chronic dosing strategies with New Zealand blackcurrant provide a nutritional ergogenic effect for Ironman athletes to enhance swimming, cycling and running performance.

The Responsiveness of Exercise Tests in COPD: A Randomized Controlled Trial

BackgroundChronic obstructive pulmonary disease (COPD) is characterised by reduced exercise tolerance and improving physical performance is an important therapeutic goal. A variety of exercise tests are commonly used to assess exercise tolerance, including laboratory and field-based tests. The responsiveness of these tests to common COPD interventions is yet to be compared, but may inform test selection in clinical and research settings. Research QuestionWhat exercise test possesses the greatest sensitivity to change pre- to post-intervention in patients with COPD? Study Design and Methods154 patients with symptomatic COPD were recruited and randomised (2:1:1) to six weeks of long-acting muscarinic antagonist (LAMA), pulmonary rehabilitation (PR), or usual care (UC). Pre- and post-intervention, participants performed a ramp-incremental and constant work rate cycle ergometer exercise test (ICET and CWRCT), incremental and endurance shuttle walk test (ISWT and ESWT), six-minute walk test (6MWT), and a four metre gait speed test (4MGS). Results103 participants (67 ± 8 y; 75 [73%] males; FEV1: 50.6 ± 16.8 % predicted) completed the study. Significant improvements in the ICET, CWRCT, ISWT, ESWT, and 6MWT were observed following PR (p<0.05), with the greatest improvements seen in the constant work rate protocols (% change: CWRCT: 42%; ESWT: 41%). InterpretationThe ESWT and CWRCT appeared to be the most responsive exercise test protocols to LAMA and PR. The magnitude of change was much greater after a programme of rehabilitation compared to bronchodilator therapy.

Ni-Derived NiO Nanosphere Electrocatalyst for Hydrogen Evolution Reaction: The Effect of Synthesis Variables on Activity and Durability

Transition to a decarbonized society will rely on clean energy resources, in particular on "green” hydrogen—a renewable energy carrier that can be generated via water electrolysis [1]. Unlike proton exchange membrane water electrolyzers (PEMWE), anion exchange membrane water electrolyzers (AEMWEs) enable the use of earth-abundant transition metals in both the cathode and anode [2]. In addition, unlike liquid alkaline water electrolyzers, which use a highly concentrated alkaline media (6 M KOH), AEMWEs can operate with low-concentrated electrolyte, and even pure water [3]. Developing active and durable platinum group metal-free (PGM-free) electrocatalysts is crucial for the large-scale implementation of the AEMWE technology. Ni-based electrocatalysts have shown good activity towards the hydrogen evolution reaction (HER) in alkaline media [4]. Herein, carbon supported Ni-derived NiO nanosphere electrocatalysts are synthetized via a sol-gel method followed by thermal treatment under reducing atmosphere. We explored several synthesis parameters, i.e., Ni-to-carbon ratio, annealing temperature, and annealing time. We also investigated the impact of these synthesis variables on the HER activity in alkaline electrolyte. The catalysts were characterized by XRD, SEM, and EDS. The formation of Ni metal particles with a thin oxygen-rich layer on the surface was demonstrated by microscopy and crystallographic characterization. Following optimization, the HER overpotential of the best performing electrocatalyst at a current density of 10 mA cm−2 was reduced to ca. 130 mV. The catalyst durability was tested over 100 h in KOH solutions at different electrolyte concentrations using various testing protocols such as constant current hold and potential cycling. The catalyst showed higher HER activity (100 mV lower HER overpotential) and better durability behavior (0.15 mV/h lower degradation rate) compared to a commercial Ni supported Vulcan XC-72 electrocatalyst.

The Range of Influence across Commercial Glass Fiber Separators on the Cycling of the Zinc Metal Anode

Aqueous zinc-ion batteries (AZIBs) have attracted significant research attention due to their promising potential for large-scale energy storage applications in support of the rapid global growth of renewable wind and solar energy generation. However, challenges associated with the limited cycling life and low energy density of AZIBs persist as the critical limiting factors preventing their practical use in utility-scale energy storage applications [1]. Throughout zinc-ion research working to address these challenges, commercial glass fiber (GF) membranes are often used as the separator in studies investigating cathode, electrolyte, and anode designs [2]. Nevertheless, commercial GF membranes are available with a range of physicochemical properties, and the specific details of the selected membrane are often missing in published studies. In our work, we systematically compare Whatman™ GF separators (GF/A, GF/B, GF/C, GF/D, and GF/F) to assess the influence of the separator’s physicochemical properties (i.e., pore size and thickness) on the cycling life and cell-to-cell variability across multiple trials of Zn|Zn cells. Under constant current cycling, significant differences were observed in the cycling life and cell-to-cell consistency depending on the pore size and thickness of the GF separator [3]. In addition, our use of micro-computed X-ray tomography explores the associations between the separator’s pore size and zinc deposition morphology and provides visual identification of the failure mechanism corresponding with an overpotential collapse. The results of this work clarify the importance of GF separator selection and the separator’s influence to support the improvement of other cell components.

Separating Cationic and Anionic Redox Activity in the Lithium-Rich Antiperovskite (Li2Fe)SO.

Lithium-rich antiperovskites promise to be a compelling class of high-capacity cathode materials due to the existence of both cationic and anionic redox activity. Little is however known about the effect of separating the electrochemical cationic process from the anionic process and the associated implications on the electrochemical performance. In this context, we report the electrochemical properties of the illustrative example of three different (Li2Fe)SO materials with a focus on separating cationic from anionic effects. With the high-voltage anionic process, an astonishing electrochemical capacity of around 400 mAh g-1 can initially be reached. Our results however identify the anionic process as the cause of poor cycling stability and demonstrate that the fading reported in previous literature is avoided by restricting to only the cationic processes. Following this path, our (Li2Fe)SO-BM500 shows strongly improved performance as indicated by constant electrochemical cycling over 100 cycles at a capacity of around 175 mAh g-1 at 1 C. Our approach also allows us to investigate the electrochemical performance of the bare antiperovskite phase excluding extrinsic activity from initial or cycling-induced impurity phases. Our results underscore that synthesis conditions are a critical determinant of electrochemical performance in lithium-rich antiperovskites, especially with regard to the amount of electrochemical secondary phases, while the particle size has not been found to be a crucial parameter. Overall, separating and understanding the effects of the cationic from the anionic redox activity in lithium-rich antiperovskites provides the route to further improve their performance in electrochemical energy storage.

Firing rate adaptation affords place cell theta sweeps, phase precession, and procession

Hippocampal place cells in freely moving rodents display both theta phase precession and procession, which is thought to play important roles in cognition, but the neural mechanism for producing theta phase shift remains largely unknown. Here, we show that firing rate adaptation within a continuous attractor neural network causes the neural activity bump to oscillate around the external input, resembling theta sweeps of decoded position during locomotion. These forward and backward sweeps naturally account for theta phase precession and procession of individual neurons, respectively. By tuning the adaptation strength, our model explains the difference between ‘bimodal cells’ showing interleaved phase precession and procession, and ‘unimodal cells’ in which phase precession predominates. Our model also explains the constant cycling of theta sweeps along different arms in a T-maze environment, the speed modulation of place cells’ firing frequency, and the continued phase shift after transient silencing of the hippocampus. We hope that this study will aid an understanding of the neural mechanism supporting theta phase coding in the brain.

Firing rate adaptation affords place cell theta sweeps, phase precession, and procession.

Hippocampal place cells in freely moving rodents display both theta phase precession and procession, which is thought to play important roles in cognition, but the neural mechanism for producing theta phase shift remains largely unknown. Here, we show that firing rate adaptation within a continuous attractor neural network causes the neural activity bump to oscillate around the external input, resembling theta sweeps of decoded position during locomotion. These forward and backward sweeps naturally account for theta phase precession and procession of individual neurons, respectively. By tuning the adaptation strength, our model explains the difference between 'bimodal cells' showing interleaved phase precession and procession, and 'unimodal cells' in which phase precession predominates. Our model also explains the constant cycling of theta sweeps along different arms in a T-maze environment, the speed modulation of place cells' firing frequency, and the continued phase shift after transient silencing of the hippocampus. We hope that this study will aid an understanding of the neural mechanism supporting theta phase coding in the brain.