Recovery Of Activity Research Articles

Toxic effect of ciprofloxacin on the photosynthesis reactions in microalga Scenedesmus quadricauda (Turp.) Bréb.

Ciprofloxacin (CIP) is widely used broad-spectrum antimicrobial drug of fluoroquinolone family. The widespread use of ciprofloxacin increases its release into the environment. Ciprofloxacin is detected in aquatic ecosystems potentially harming aquatic organisms. The CIP effect on photosynthetic organisms is not fully studied. In this study we examined the CIP effect on green freshwater microalgae Scenedesmus quadricauda (Turp.) Bréb. using chlorophyll fluorescence methods (JIP test parameters and rapid light curves). A significant decrease in the cell number was observed at ≥10 mg/L of сiprofloxacin in comparison with control. Analysis of chlorophyll fluorescence parameters obtained from OJIP transients revealed the changes in photosynthetic reactions in сiprofloxacin treatment. Ciprofloxacin was found to inhibit electron transport rate in photosystem II (PSII). The decrease in the quantum yield of electron transport in photosystem II (φEo) was accompanied by the decrease in performance index (PIABS) and an increase in energy dissipation (DI0/RC). Ciprofloxacin enhanced the photosensitivity of microalgae but did not inhibit the recovery of photosynthetic activity after the photooxidative stress. In this regard the effect of CIP differs from that of the well-known antibiotic chloramphenicol that inhibits the resynthesis of plastid proteins and, accordingly, the recovery of photosynthetic activity associated with the resynthesis of PSII protein D1. Among the fluorescence parameters, PIABS was found to be the most stress-specific; therefore it can be proposed to detect an early toxic CIP effect in microalgae.

Competitive bio-augmentation overcoming unusual direct inhibitor inefficacy in mainstream nitrite-oxidizing bacteria suppression: Unveiling the underpinnings in microbial and nitrogen metabolism aspects

The long-stabilized mainstream partial nitritation/Anammox (PN/A) process continues to encounter significant challenges from nitrite-oxidizing bacteria (NOB). Therefore, this study aimed to determine an efficient, rapid, and easily implementable strategy for inhibiting NOB. A laboratory-scale reactor was operated continuously for 325 days, experiencing NOB outbreak in mainstream and recovery with simulated sidestream support. The results show that direct inhibitory strategies including intermittent aeration and approximately 35 mg/L free ammonia had unusual weak inhibitory effects on NOB activity. Subsequently, the exogenous Anammox from sidestream employed as a competitive bio-augmentation approach rapidly inhibited NOB dynamics. Evidence suggests that the damaged hydroxyapatite granules under low pH conditions might have contributed to NOB dominance by diminishing Anammox bacteria activity, thereby creating a substrate-rich environment favoring NOB survival. In contrast, the introduction of exogenous Candidatus Kuenenia facilitated the nitrogen removal efficiency from 32.5 % to over 80 %. This coincided with a decrease in the relative abundance of Nitrospira from 16.5 % to 2.7 % and NOB activity from 0.34 to 0.07 g N/(g mixed liquor volatile suspended solid)/d. Metagenomic analysis reveals a decrease in the functional potential of most nitrite transport proteins, coupled with a significant increase in eukaryotic-like serine/threonine-protein kinase involved in cellular regulation, during the Anammox activity recovery. This study's findings reveal the feasibility of the bio-augmentation based on substrate competition, wherein sidestream processes support the mainstream PN/A integration, offering significant potential for practical applications.

Abstract 2061: A proven activity-based workflow for the identification and characterization of time-dependent kinase inhibitors using a continuous assay format

Abstract Time-dependent inhibitors (TDIs) of enzyme targets offer distinct advantages for the development of potent and selective compounds with favorable pharmacokinetic and pharmacodynamic properties. Such inhibitors are characterized by non-linear progress curves: after an initial inhibited velocity, a rate constant governs the transition to a final steady-state reaction rate of the inhibited enzyme. A final rate of zero indicates irreversible inhibition, whereas a non-zero final rate indicates slow-binding inhibition. Characterizing these inhibitory modes of action is enabled with a continuous assay format that avoids the common pitfalls and misleading results seen with end-point assays. A continuous assay format enables efficient and robust determination of the kinetic parameters required to drive structure-activity relationship optimization to streamline the development of more effective drugs. It is important to note that simple IC50s for TDIs will not suffice, and can, indeed, also be misleading. We have developed a robust three-step workflow based on kinetic catalytic activity measurements to quickly identify and characterize TDIs. First, dose-response experiments are conducted with and without an enzyme-inhibitor preincubation step. The curvature of the reaction progress curve in the non-preincubated experiment and a shift in IC50 from the preincubated experiment are indicative of TDI. In the absence of TDI, simple IC50s are reported with, if possible, Ki values. If TDI is present, a second experiment is conducted to assess compound reversibility using either a jump-dilution protocol or a novel free-compound clearance method that uses gel filtration spin columns or spin plates. In either protocol, forward progress curve analysis is used to monitor the recovery of enzymatic activity after dilution of inhibitor in solution. Lastly, the potency of the inhibitor is evaluated using kinetic experiments tailored to the nature of the inhibition – either reversible or irreversible. If reversible, then the rate constant from the reversibility experiment is used to determine the residence time of the molecule. If irreversible, then a 24-point dose-response experiment with serial 1.5-fold dilutions is performed, and all the progress curves are globally fit to determine kinact/KI, and, if possible, kinact and KI separately. The method will be fully described through the characterization of known EGFR inhibitors of three inhibition types: fast-off (Gefitinib), slow binding (Lapatinib), and irreversible (Osimertinib). Citation Format: Earl May, Daniel Urul, Khanh Huynh, Susan Cornell-Kennon, Venkatesh Nemmara, Zhibing Lu, Samuel Hoare, Michelle Lyles, Erik Schaefer. A proven activity-based workflow for the identification and characterization of time-dependent kinase inhibitors using a continuous assay format [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2061.

Abstract 7177: Development and validation of clinical pharmacodynamic biomarkers to assess treatment response to HPK1 inhibition and guide dosing decisions

Abstract Checkpoint inhibitors represent promising cancer therapeutics as they have the potential to reignite T cell activity and reverse T cell exhaustion, which is a critical mechanism of immune evasion by tumors. Hematopoietic progenitor kinase 1 (HPK1) is a negative regulator of T-cell signaling that has recently emerged as a novel target for cancer immunotherapy. Inhibition of HPK1 can restore T cell function and anti-tumor immune responses, and several HPK1 inhibitors are currently under pre-clinical development, or clinical evaluation. Identifying clinically useful pharmacodynamic (PD) biomarkers in response to HPK1 inhibition is critical to characterize exposure-response relationship in early-phase trials and inform dose selection for later-phase studies. However, development and implementation of clinical PD assays are challenging because high sensitivity and specificity are required. Here, we developed a multi-biomarker strategy that combines a proximal biomarker (SLP-76 (Ser376) phosphorylation, a specific substrate of HPK1) and distal biomarkers (cytokine production) to evaluate target engagement (TE) and establish proof of mechanism (POM) of HPK1 inhibitors to determine their comprehensive PD profile. These PD biomarker assays were developed using peripheral blood as a surrogate tissue to assess HPK1 inhibition-induced pSLP-76 level decrease and cytokine levels increase, thus reflecting drug inhibitory effects and T-cell activity recovery. However, the lack of basal levels of these biomarkers presented a challenge for clinical workflow, as ex-vivo T-cell receptor stimulation of the clinical specimen is required after collection. Phosphoflow cytometry was prioritized over several technology platforms evaluated for quantifying blood pSLP-76 levels because of superior assay performance and signal stability under the developed clinical workflow. Blood cytokines upregulated upon HPK1 inhibition were first identified using targeted proteomics. IFNγ, IL2, TNFα, and IL17A were next confirmed and validated using quantitative immunoassays. Both pSLP-76 and whole blood cytokine workflows were thoroughly optimized for every step of sample handling from specimen processing at clinical sites to sample analysis at testing lab to ensure standardized, precise, and robust assay performance for clinical application. In addition, consistent HPK1 inhibition potency values were achieved using blood from cancer patients, demonstrating that the established PD biomarker assays apply to the clinical target population. In conclusion, robust peripheral TE and POM biomarkers were successfully developed to support future phase I/II studies with HPK1 inhibitors. These are expected to enable characterization of the exposure-response relationships and help define the therapeutic window and optimal dose. Citation Format: Lin Jia, Yasmin Marikar-Coplin, Jeff Chen, Kevin Xu, Deanna A. Mele, Nadia Luheshi, Sonia Iyer, Anton I. Rosenbaum, Sonia Terrillon. Development and validation of clinical pharmacodynamic biomarkers to assess treatment response to HPK1 inhibition and guide dosing decisions [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7177.

Cyanide Insensitive Oxidase Confers Hydrogen Sulfide and Nitric Oxide Tolerance to Pseudomonas aeruginosa Aerobic Respiration.

Hydrogen sulfide (H2S) and nitric oxide (NO) are long-known inhibitors of terminal oxidases in the respiratory chain. Yet, they exert pivotal signaling roles in physiological processes, and in several bacterial pathogens have been reported to confer resistance against oxidative stress, host immune responses, and antibiotics. Pseudomonas aeruginosa, an opportunistic pathogen causing life-threatening infections that are difficult to eradicate, has a highly branched respiratory chain including four terminal oxidases of the haem-copper type (aa3, cbb3-1, cbb3-2, and bo3) and one oxidase of the bd-type (cyanide-insensitive oxidase, CIO). As Escherichia coli bd-type oxidases have been shown to be H2S-insensitive and to readily recover their activity from NO inhibition, here we tested the effect of H2S and NO on CIO by performing oxygraphic measurements on membrane preparations from P. aeruginosa PAO1 and isogenic mutants depleted of CIO only or all other terminal oxidases except CIO. We show that O2 consumption by CIO is unaltered even in the presence of high levels of H2S, and that CIO expression is enhanced and supports bacterial growth under such stressful conditions. In addition, we report that CIO is reversibly inhibited by NO, while activity recovery after NO exhaustion is full and fast, suggesting a protective role of CIO under NO stress conditions. As P. aeruginosa is exposed to H2S and NO during infection, the tolerance of CIO towards these stressors agrees with the proposed role of CIO in P. aeruginosa virulence.

6-Hydroxy-2,2,4-trimethyl-1,2,3,4-tetrahydroquinoline Demonstrates Neuroprotective Properties in Experimental Parkinson's Disease by Enhancing the Antioxidant System, Normalising Chaperone Activity and Suppressing Apoptosis.

Parkinson's disease (PD) is a neurodegenerative disease, whereby disturbances within the antioxidant defence system, increased aggregation of proteins, and activation of neuronal apoptosis all have a crucial role in the pathogenesis. In this context, exploring the neuroprotective capabilities of compounds that sustain the effectiveness of cellular defence systems in neurodegenerative disorders is worthwhile. During this study, we assessed how 6-hydroxy-2,2,4-trimethyl-1,2,3,4-tetrahydroquinoline (HTHQ), which has antioxidant properties, affects the functioning of the antioxidant system, the activity of NADPH-generating enzymes and chaperones, and the level of apoptotic processes in rats with rotenone-induced PD. Six groups of animals were formed for our experiment, each with 12 animals. These were: a control group, animals with rotenone-induced PD, rats with PD given HTHQ at a dose of 50mg/kg, rats with PD given HTHQ at a dose of 25mg/kg, animals with pathology who were administered a comparison drug rasagiline, and control animals who were administered HTHQ at a dose of 50mg/kg. The study results indicate that administering HTHQ led to a significant decrease in oxidative stress in PD rats. The enhanced redox status in animal tissues was linked with the recovery of antioxidant enzyme activities and NADPH-generating enzyme function, as well as an upsurge in the mRNA expression levels of antioxidant genes and factors Nrf2 and Foxo1. Administering HTHQ to rats with PD normalized the chaperone-like activity and mRNA levels of heat shock protein 70. Rats treated with the compound displayed lower apoptosis intensity when compared to animals with pathology. Therefore, owing to its antioxidant properties, HTHQ demonstrated a beneficial impact on the antioxidant system, resulting in decreased requirements for chaperone activation and the inhibition of apoptosis processes triggered in PD. HTHQ at a dose of 50mg/kg had a greater impact on the majority of the examined variables compared to rasagiline.

The influence of sports games as a means of recreation and health activity on the physical fitness of students of 1-2 courses of vocational education

The article examines the content of students' recreational and health activities. An analysis of specialized literature on the selected problem was carried out. The relevance of this topic is substantiated. The importance and place of health and recreation technologies in ensuring the quality of life of student youth has been established. Recreational health activities are the restoration of a person's physical and psychological state. It has been proven by many specialists that sports games as a means of physical activity have a number of advantages due to their emotionality, accessibility and health-recreational effect, which is due to the impact on the physical and psycho-emotional sphere of students of higher education institutions. Sports games, in addition to the health-improving effect, change the activity environment, which is accompanied by various situations and movements, bring pleasure, provide active recovery, develop physical qualities. The purpose of the study is to determine the influence of sports games as a means of recreational and health-improving activities on the physical fitness of students of the 1st-2nd years of higher education. Methodology. 60 students from 1-2 courses took part in the study. We assessed the determination of students' physical fitness based on the results of 4 tests. The experiment lasted 1 semester, and the frequency of classes was 2 times a week. To ensure the objectivity of the research, several general scientific and pedagogical methods were used: analysis and synthesis of scientific literature on the selected problem; pedagogical methods and methods of statistical data processing. Conclusions. A pedagogical experiment was conducted, which made it possible to determine the effectiveness of the use of modern technologies of physical recreation, and especially sports games as a means of improving the physical fitness of students of 1-2 courses who attended physical education classes.

Immobilization of Urease from Psophocarpus tetragonolobus L. DC. using Natrium Alginate Supporting Matrix

Urease is an enzyme that has the role to hydrolyzes urea into ammonia and carbon dioxide. Immobilization is one of the most efficient strategies to improve its activity recovery and properties of urease. This research started with the germination of winged beans for 8 days. The winged bean was extracted by grinding using a mortar and pestle and then added with phosphate buffer at pH 7. The solution was homogenized using a stirrer and then centrifuged in cold conditions so that an extract of urease was obtained. Urease extracts were immobilized using a chitosan-supporting matrix. Optimization of the immobilization process of urease extract includes the concentration of chitosan and sodium tripolyphosphate (TPP) and contact time. The obtained was free and immobilized urease activities then tested using the Nessler method and measured using a UV-Vis spectrophotometer with a wavelength of 500 nm. The obtained data were then statistically tested using ANOVA. Urease-chitosan beads were further tested in repeated use and analyzed with SEM-EDX (Scanning Electron Microscopy-Energy Dispersive X-ray). The results showed that the optimum conditions for making urease-chitosan beads were a concentration of 4% (w/v), 2.5% (w/v) TPP, and 60 minutes of contact time, resulting in an activity value of 15.076 U/mL, which can be used 5 times with 46% activity from the initial activity. The EDX analysis results after the addition of the enzyme showed atom composition changes leading to increasing carbon and nitrogen contents. The existence of phosphor showed that TPP was a chitosan cross-link compound.
 
 Keywords: Chitosan, immobilization, TPP, urease, winged bean

Endocardial repolarization dispersion in BrS: A novel automatic algorithm for mapping activation recovery interval.

Repolarization dispersion in the right ventricular outflow tract (RVOT) contributes to the type-1 electrocardiographic (ECG) phenotype of Brugada syndrome (BrS), while data on the significance and feasibility of mapping repolarization dispersion in BrS patients are scarce. Moreover, the role of endocardial repolarization dispersion in BrS is poorly investigated. We aimed to assess endocardial repolarization patterns through an automated calculation of activation recovery interval (ARI) estimated on unipolar electrograms (UEGs) in spontaneous type-1 BrS patients and controls; we also investigated the relation between ARI and right ventricle activation time (RVAT), and T-wave peak-to-end interval (Tpe) in BrS patients. Patients underwent endocardial high-density electroanatomical mapping (HDEAM); BrS showing an overt type-1 ECG were defined asOType1, while those without (latent type-1 ECGandLType1) received ajmaline infusion. BrS patients only underwent programmed ventricular stimulation (PVS). Data were elaborated to obtain ARI corrected with the Bazett formula (ARIc), while RVAT was derived from activation maps. 39 BrS subjects (24 OType1 and 15 LTtype1) and 4 controls were enrolled. OType1 and post-ajmaline LType1 showed longer mean ARIc than controls (306 ± 27.3 ms and 333.3 ± 16.3 ms vs. 281.7 ± 10.3 ms, p = .05 and p < .001, respectively). Ajmaline induced a significant prolongation of ARIc compared to pre-ajmaline LTtype1 (333.3 ± 16.3 vs. 303.4 ± 20.7 ms, p < .001) and OType1 (306 ± 27.3 ms, p < .001). In patients with type-1 ECG (OTtype1 and post-ajmaline LType1) ARIc correlated with RVAT (r = .34, p = .04) and Tpec (r = .60, p < .001), especially in OType1 subjects (r = .55, p = .008 and r = .65 p < .001, respectively). ARIc mapping demonstrates increased endocardial repolarization dispersion in RVOT in BrS. Endocardial ARIc positively correlates with RVAT and Tpec, especially in OType1.

Synergies of Mn modified Fe-based MOF enhanced catalytic ozonation: charge transfer and multiple sites mechanism

The conjoint improvement of catalytic ozonation activity and stability for MOFs materials has always been an urgent challenge. Metal doping offers a viable approach to inspire the interaction between active components and O3 due to the optimization of electronic structure and introduction of surface-active sites. In this work, 88A-Mn catalyst derived from MIL-88A was prepared by loading Mn to MIL-88A with a simple pyrolysis method. The structure and physical characterizations confirmed the coexistence of Fe and Mn in the catalyst. The 88A1-Mn1-350 exhibited the efficient degradation of ibuprofen in catalytic ozonation system, with its degradation rate showing 3.6 times and 2.6 times higher than those of the O3 system and the 88A-T/O3 system, respectively. Mechanism analysis indicated the synergistic effect among Fe/Mn interaction, surface hydroxyl group, and O-C=O group promoted the continuous generation of ROS, including ·OH and ·O2-. Specifically, the regeneration of Fe2+ derived from the Mn doping contributed to the recovery of catalytic activity and played an indispensable role in maintaining high efficiency. In addition, 88A1-Mn1-350 possessed outstanding stability in a wide range of pH (3-11) and the coexistence of anions. It also exhibited the superiority compared with traditional catalysts. This finding provides a feasible modification approach to enhance the property of MOFs materials, and achieves the efficient remove of refractory organics in catalytic ozonation system.

Calcium-based MOFs as scaffolds for shielding immobilized lipase and enhancing its stability

The enzyme immobilization technology has become a key tool in the field of enzyme applications; however, improving the activity recovery and stability of the immobilized enzymes is still challenging. Herein, we employed a magnetic carboxymethyl cellulose (MCMC) nanocomposite modified with ionic liquids (ILs) for covalent immobilization of lipase, and used Ca-based metal–organic frameworks (MOFs) as the support skeleton and protective layer for immobilized enzymes. The ILs contained long side chains (eight CH2 units), which not only enhanced the hydrophobicity of the carrier and its hydrophobic interaction with the enzymes, but also provided a certain buffering effect when the enzyme molecules were subjected to compression. Compared to free lipase, the obtained CaBPDC@PPL–IL–MCMC exhibited higher specific activity and enhanced stability. In addition, the biocatalyst could be easily separated using a magnetic field, which is beneficial for its reusability. After 10 cycles, the residual activity of CaBPDC@PPL–IL–MCMC could reach up to 86.9%. These features highlight the good application prospects of the present immobilization method.

Recovery After High-Intensity Interval Training in Professional Soccer Players: Passive-Active Combination Recovery Technique

Objective: The aim of this study is to investigate which of the passive recovery (PR), active recovery (AR) and passive-active combination recovery (PAR) techniques applied after the end of high-intensity interval training (HIIT) was more effective in professional super league soccer players. Method: 28 trained professional male soccer players (age: 24.79±2.75 years, height: 180.50±5.81 cm, weight: 74.18±5.47 kg) from the Türkiye Super League team participated in this study voluntarily. Before the study, participants were assigned to 3 groups according to heart rate (HR) and lactic acid (La) levels. Each HIIT load intensity was determined according to the Karvonen method. HIIT sessions were performed for 5 repetitions of 2 minutes (1 set = 5x2 minutes) and a 30-second rest was given between repetitions. At the end of the set, a 2-minute recovery period was applied. Three different recovery techniques, PR, AR and PAR, were applied alternately to each group at the end of the HIIT programs. Participants' HR and La values were taken at the end of HIIT and recovery techniques. Differences between the obtained data were determined by repeated measures one-way ANOVA and multiple comparison tests. P&lt;0.05 level was considered significant in all tests. Results: Although there was no significant difference in La levels between groups (p&gt;0.05), significant differences were observed between HR and loading intensities (p&lt;0.05). According to the results of multiple comparisons, the recoveries in HR and La levels were found to be significant in favor of the PAT group (p&lt;0.05). Discussion: It can be thought that football players increase the mitochondrial biogenesis, oxidative and lipid oxidation capacities of skeletal muscles due to adaptations to HIIT and similar heavy workouts. Depending on these developments in the athletes' condition, it can be said that all three recovery techniques affect the decrease of HR and La in the two-minute period. Conclusion: PR and PAR techniques were effective in reducing HR levels. AR and PAR techniques were effective in reducing La levels. Therefore, it can be said that the PAR technique is more effective in reducing both HR and La levels together.

Unveiling the urban resilience in cities of China, a study on NO2 concentrations and COVID-19 pandemic

COVID-19 can be considered as the largest public health incident since 2019, posing disturbances to the medical, economic, and social systems. Understanding different levels of city resilience to the impact of COVID-19 on sustainable urban development is therefore essential. In this paper, we analyzed the evolution of the pandemic, the recovery of urban activities and major drivers of urban resilience to COVID-19 based on urban activity patterns derived from NO2 monitoring stations from 217 cities in China. It is observed that nearly all urban activities have been affected by the epidemic with a reduced NO2 emission, indicating a significant decline in the intensity of urban activity. The recovery patterns of human activity among different cities show that: (1) northern cities where low-resilience cities agglomerated have been severely affected. As of April 31, 2020, 12 northern cities have not recovered to pre-epidemic levels; (2) about three-quarters of the cities went through multiple stages to return to the pre-pandemic level, which related to both pandemic stress and prevention measures; (3) about 46.04% of the cities experienced increasing activity patterns that exceeded the pre-epidemic activity level. It is also observed that urban resilience can behave quite differently driven by variations in green coverage, economic aggregate, employment security, and medical system. Our study highlights the potential of an elevated urban resilience by optimizing the urban layout, improving the quantity and quality of green space, and enhancing the medical system.

Telehealth Movement-to-Music With Arm-Based Sprint-Intensity Interval Training to Improve Cardiometabolic Health and Cardiorespiratory Fitness in Children With Cerebral Palsy: Protocol for a Pilot Randomized Controlled Trial.

Children with mobility disabilities, including those with cerebral palsy, have limited options and limited time to exercise to manage their cardiometabolic health and cardiorespiratory fitness. Regular cardiovascular exercise during childhood is a critical health behavior for preventing health decline in adulthood. Thus, there is an urgent need for accessible, age-appropriate, convenient exercise modalities in this group. Sprint-intensity interval training (SIT), combined with telehealth procedures, may be ideal for children with disabilities. SIT includes repetitive bouts of maximal exercise effort combined with rest periods, which can be effective in eliciting comparable results to moderate-exercise training with very short training durations. This phase 1 pilot feasibility randomized controlled trial aims to investigate the potential effects of a 12-week SIT program on indicators of cardiorespiratory fitness and cardiometabolic health among children with cerebral palsy. An ancillary aim is to evaluate the feasibility of the program through several process feasibility metrics. This study uses a 2-armed parallel group design. A total of 50 physically inactive children with cerebral palsy (aged 6-17 years) will be randomly allocated into 1 of 2 groups: a 12-week SIT or a waitlist control group that continues habitual activity for 12 weeks. The SIT prescription includes 3 tele-supervised sessions per week with 30 repeated sequences of 4 seconds of maximal arm exercise, with active recovery, warm-up, and cooldown periods (for an approximately 20-minute total session). SIT includes guided videos with child-themed arm routines and music. The exercise sessions will be remotely supervised through a web-based videoconference application and include safety monitoring equipment. Outcomes are measured at pre- and postintervention (weeks 0 and 13, respectively). Health outcome measures include peak oxygen consumption (VO2 peak), measured by a graded exercise test; high-sensitivity C-reactive protein and blood insulin, hemoglobin A1c, triglycerides, and cholesterol using a finger stick dried blood spot test; blood pressure, using a sphygmomanometer; and body composition (total mass, total lean mass, tissue % lean, and tissue % fat) using dual x-ray absorptiometry. Feasibility will be evaluated by the following metrics: adverse events or problems experienced throughout the intervention related to participant safety; perceived enjoyment; and recruitment, enrollment, and attrition rates. Recruitment procedures started in November 2023. All data are anticipated to be collected by February 2025. Full trial results are anticipated to be analyzed and submitted for publication by March 2025. Secondary analyses of data will be subsequently published. This trial tests an accessible and low-cost exercise program that leverages principles of high-intensity exercise to provide a convenient program for children with physical disabilities. Knowledge obtained from this study will inform the development of a larger trial for improving the cardiometabolic health, cardiorespiratory fitness, and well-being of children with physical disabilities. ClinicalTrials.gov NCT05619211; https://clinicaltrials.gov/study/NCT05619211. DERR1-10.2196/56499.

Easy interval method, an alternative approach to improve anaerobic threshold speed

This paper presents the specific training method in distance running developed by the Dutch running coach Herman Verheul and successfully applied in the 1970s, its historical background, its afterlife, and its possible applications. The Verheul method can be traced back to the Stampfl interval method used in the 1960s. It involves the use of shorter (200 and 400 meters) and longer (1000 and later 2000 meters) interval training sessions on a daily basis. The method is characterised by a low intensity of partial distances compared to traditional interval training and a relatively long active recovery period equal to the interval distance. For these reasons, the workouts remain predominantly aerobic, without significant lactic acid accumulation, allowing interval training to be used daily and avoiding over-exertion. The method allows runners to achieve high weekly volumes at high running speeds, crucial for establishing anaerobic threshold speed (vLT2) and economical running movement (RE), essential for successful distance running performance. The easy interval method offers an alternative means of improving anaerobic threshold speed. It may provide a new tool to the recently used sustained tempo runs and the anaerobic threshold intervals that are prevalent today.

Constitutive model and activation recovery performance of Fe-SMA: Experimental and theoretical study

In this study, the static tensile properties, activation recovery properties, and post-activation static tensile properties of the China-made iron-based shape memory alloys (Fe-SMA) were experimentally studied and theoretically analyzed. The material parameters of the Ramberg-Osgood curve are modified based on the static tensile tests of Fe-SMA plates, leading to the proposal of a static tensile constitutive model suitable for Fe-SMA. The applicability analysis of the theoretical model indicates that the calculated curve achieves an accuracy of R2 ≥ 0.9. Subsequent activation tests revealed a locally optimal combination of pre-strain and activation temperature, which is concluded to be associated with the martensite content. Hot-rolled Fe-SMA plates demonstrate local maximum utilization when subjected to a 4% pre-strain and an activation temperature of 300 °C, resulting in a recovery stress of 314 MPa. Moreover, it has been determined that the two activation modes, namely single heating and multiple-cyclic heating, do not significantly impact the final recovery stress of hot-rolled Fe-SMA plates. Therefore, the multiple-cyclic activation of Fe-SMA can be utilized to compensate for prestress loss in practical applications. Furthermore, a comprehensive constitutive model for Fe-SMA is proposed based on the results of the post-activation static tensile tests. This model provides an accurate description of the static-tensile stress-strain relationship of Fe-SMA during pre-straining and after activation. This study focuses on investigating the constitutive relationship and activation recovery performance of Fe-SMA, providing an experimental basis, data support, and theoretical analysis for the practical application and further analysis of Fe-SMA in structural reinforcements.

Enrichment of electrogenic microbes on surface-modified stainless steel 304L for rapid start-up of microbial electrochemical sensors

Stainless steel (SS) 304L, a cost-effective and mechanically robust material, is widely used in microbial electrochemical systems as an anode due to its versatility. However, poor biocompatibility and low corrosion resistance limit its potential. This study explores rapid SS surface modification techniques to enhance the sensitivity of microbial electrochemical sensors. Four coatings, namely electroreduction, carbon-coated, flame oxidised, and graphene-coated, were applied to SS electrodes. Surface morphology and characteristics were examined through FESEM-EDX and Raman profiling. The biosensor start-up and microbial enrichment demonstrated an exponential increase in current density, with carbon-based electrodes outperforming iron-based ones. The modified electrodes exhibited enhanced microbial-electrode interactions, evident in altered electrode potential. Starvation and recovery tests revealed distinct patterns, with carbon-coated electrodes showcasing rapid recovery. The air-in-chamber test indicated immediate loss and subsequent recovery of microbial activities upon water circulation. Surface modification significantly influenced the microbial response, with carbon-based coatings demonstrating superior performance. This study provides valuable insights into SS surface modification for improving microbial electrochemical sensor sensitivity, holding promise for diverse applications in environmental monitoring and biosensing.

An Active Power Recovery Control Method for Post-Fault of Photovoltaic DC Access System Considering Communication Availability

An Active Power Recovery Control Method for Post-Fault of Photovoltaic DC Access System Considering Communication Availability

A Dynamic Equivalent Method for PMSG-WTG Based Wind Farms Considering Wind Speeds and Fault Severities

The dynamic security assessment of power systems needs to scan contingencies in a preselected set through time-domain simulations. With more and more wind power generation integrated into power systems, the complexity of simulation will increase greatly if wind farms are modeled in detail. Thus, it is critical to develop dynamic equivalent methods for wind farms. The dynamic response characteristics of permanent magnet synchronous generator-wind turbine generators (PMSG-WTGs) are not only influenced by their control strategies, but also by the operating wind speeds and the fault severities. Thus, this paper proposes a dynamic equivalent method for a PMSG-WTG based wind farm considering the wind speeds and the fault severities. Firstly, we propose a clustering method based on the operating wind speed and the terminal voltage of each PMSG-WTG at the end of the fault. Then, a single-machine equivalent method is introduced for each cluster of PMSG-WTGs. For the cluster of PMSG-WTGs with active power ramp recovery process, an equivalent model with segmented ramp rate limitation for active current is designed. In order to obtain the clustering indicators, a simulation-based iterative method is put forward. Eventually, the efficiency and accuracy of the proposed method are verified by the simulation results.

역할 과부하와 과업 수행의 관계

This study aimed to examine the in-depth mechanisms of the relationship between role overload and task performance by investigating whether different types of recovery experiences would explain or modify the relationship. Specifically, we tested moderated mediation models where active recovery experiences (i.e., mastery and control) would moderate the indirect path from role overload to task performance via passive recovery experiences (i.e., psychological detachment and relaxation). Participants were 277 employees in South Korea who did not take a day off on the first survey day who completed a two-wave online survey before and after the weekend. These results showed that role overload during a week was negatively correlated with passive recovery experiences during the weekend. There was a significant moderating effect of control between relaxation and task performance, but the exact nature of interaction differed from our hypothesis, such that relaxation rather hindered task performance in low control, while there was no significant relationship in high control. Based on these findings, we discussed implications of this study and suggested directions for future research.