Search Results (55)

Background: Basketball is characterized as a high-intensity, intermittent sport that places considerable demands on the cardiorespiratory, neuromuscular, and mechanical systems. These physiological requirements are modulated by contextual variables and the athlete’s stage of biological maturation, both of which significantly influence physical fitness outcomes. Consequently, it is imperative to employ age- and development-specific assessment protocols. Objectives: This study aimed to evaluate the differences in physical fitness across competitive categories and to explore the interrelationships among the various physical assessment tests. Twenty-four male players (U14 = 12; U16 = 12) participated in this research. Methods: Athletes were monitored using WIMUPRO inertial measurement units and completed the SBAFIT test battery to evaluate physical fitness parameters. Statistical analyses included both inferential and correlational approaches, with effect sizes calculated for all relevant variables. The independent variable was the competitive age category of the players. Results: The results indicated notable differences in physical performance between developmental groups, primarily attributed to biological maturation. Significant disparities were observed in measures of aerobic capacity, linear speed, agility, and centripetal force. Conclusions: The comparative nature of this study across developmental categories offers novel insights and practical implications for talent development and training optimization. Full article

Auxiliary frequency modulation (FM) for coal-fired units has been recognized as a promising approach through multiple batteries, which is due to their rapid charging and discharging characteristics. However, long-period engineering application needs continuous optimization of operational strategies to resist the decay characteristics of the battery, which greatly increases the difficulty of promotion. Hence, two replacement strategies of the battery were first proposed in this work, and they are characterized by simple operation. To test their feasibility, a lead–acid battery was selected as one study example, and the corresponding relationship between the duration day and the replacement scheme was emphatically analyzed, according to the AGC instruction and the self-adjustment capacity of coal-fired units. Results showed that the replacement capacity of the battery is nearly linear in the duration day, while the difference from the discharge depth is negligible in this study. In addition, the capacity ratio of 1.3 to 5 is considered to have the best application potential because of the same duration days between old and new batteries. The commutative replacement can immortally extend the duration day, and obviously, the replacement process of old and new batteries always maintains that two battery groups work. Conclusively, the case analysis for two replacement strategies showed that they deeply lowered the initial capacity of the battery, which can reduce the investment costs. In a word, two replacement strategies for the battery proposed in this study provide a reference for the economic evaluation and optimization of battery use for auxiliary FM. Full article

Background: Sarcopenia is a critical complication in hemodialysis patients, associated with poor clinical outcomes, increased morbidity, and reduced quality of life. Despite this, its significance, prevalence, and risk factor data in developing countries remain limited. Objective: This study aimed to determine the prevalence of sarcopenia and identify its independent risk factors in patients undergoing maintenance hemodialysis, while evaluating its impact on physical performance, nutritional intake, and quality of life. Methods: A multicenter cross-sectional study was conducted across three hemodialysis units in Tunisia. Sarcopenia was diagnosed using EWGSOP2 (European Working Group on Sarcopenia in Older People 2) criteria based on muscle strength, muscle mass, and physical performance. Handgrip dynamometry, mid-arm and calf circumferences, gait speed, Short Physical Performance Battery (SPPB), and Timed Up and Go (TUG) test were employed. Nutritional intake was assessed using a 7-day food history. Quality of life and functional status were evaluated using the SF-36 and Barthel Index, respectively. Logistic regression was used to identify independent predictors of sarcopenia. Results: Among 118 patients (mean age 56.74 ± 14.44 years), the prevalence of sarcopenia was 42.4% (n = 50). Sarcopenic individuals exhibited significantly poorer physical performance than their non-sarcopenic counterparts. Marked reductions were observed in handgrip strength (p < 0.001, d = −1.60, very large), SPPB scores (p < 0.001, d = −1.55, very large), and increased TUG time (p < 0.001, d = 1.46, very large), indicating substantial functional impairment. Limb circumferences were also significantly lower in the sarcopenic group, including calf circumference (p = 0.002, d = −1.39, large) and mid-arm circumference (p = 0.013, d = −0.87, large). Gait speed was slower (p = 0.010, d = −0.40, small to moderate). Health-related quality of life was significantly compromised in sarcopenic individuals, with lower SF-36 total scores (p = 0.001, d = −1.96, very large) and reduced functional independence as measured by the Barthel Index (p = 0.010, d = −0.97, large). Hemoglobin levels were also significantly lower in the sarcopenic group (p = 0.048, d = −0.96, large). Dietary assessment revealed lower fiber intake (p = 0.006, d = 1.80, very large) and reduced magnesium consumption (p = 0.020, d = 0.94, large) among individuals with sarcopenia. In the multivariate logistic regression analysis, diabetes mellitus (OR = 2.14, 95% CI: 1.30–3.67, p < 0.001) and longer duration of hemodialysis (OR = 1.56, 95% CI: 1.20–2.71, p = 0.028) were identified as independent predictors of sarcopenia. A lower SPPB score (OR = 0.48, 95% CI: 0.35–0.65, p < 0.001) was associated with sarcopenia. Conclusion: Sarcopenia is highly common among hemodialysis patients and is independently linked to diabetes, treatment duration, and reduced physical performance. It significantly affects the quality of life and ability to perform daily activities. Routine screening with simple functional tests is crucial, especially in high-risk patients. Early intervention should include physical rehabilitation, nutritional support, and strict blood sugar management to decrease sarcopenia-related complications. Full article

Exploration of new ways for the direct preparation of cross-linked structures is a significant problem in terms of materials for biomedical applications, lithium batteries electrolytes, toughening of thermosets (epoxy, benzoxazine, etc.) with interpenetrating polymer network, etc. The possibility to utilize hydrosilylation and Piers–Rubinsztajn reactions to obtain cross-linked model phosphazene compounds containing eugenoxy and guaiacoxy groups has been studied. It was shown that Piers–Rubinsztajn reaction cannot be used to prepare phosphazene-based tailored polymer matrix due to the catalyst deactivation by nitrogen atoms of main chain units. Utilizing the hydrosilylation reaction, a series of cross-linked materials were obtained, and their properties were studied by NMR spectroscopy, FTIR, DSC, and TGA. Rheological characterizations of the prepared tailored matrices were conducted. This work showed a perspective of using eugenoxy functional groups for the preparation of three-dimensional hybrid phosphazene/siloxane-based materials for various applications. Full article

In order to improve energy utilization efficiency and the flexibility of resource transfer in oceanic-island-group microgrids, a water–electricity–hydrogen flexible scheduling strategy based on a multi-rate hydrogen-powered ship is proposed. First, the characteristics of the seawater desalination unit (SDU), proton exchange membrane electrolyzer (PEMEL), and battery system (BS) in consuming surplus renewable energy on resource islands are analyzed. The variable-efficiency operation characteristics of the SDU and PEMEL are established, and the effect of battery life loss is also taken into account. Second, a spatio-temporal model for the multi-rate hydrogen-powered ship is proposed to incorporate speed adjustment into the system optimization framework for flexible resource transfer among islands. Finally, with the goal of minimizing the total cost of the system, a flexible water–electricity–hydrogen hybrid resource transfer model is constructed, and a certain island group in the South China Sea is used as an example for simulation and analysis. The results show that the proposed scheduling strategy can effectively reduce energy loss, promote renewable energy absorption, and improve the flexibility of resource transfer. Full article

Lead contamination in the environment affects both humans and animals. Even with the decrease in manufactured items containing lead, contaminants persist in the landscape and may enter the food supply through animal products. In cattle, lead poisoning is associated with economic losses due to mortality and treatment costs and poses a health risk to consumers. A dairy herd was exposed to lead through feed that was contaminated with a 12-volt battery from a mixer wagon. Lead concentrations in blood and milk samples were examined over 289 days. A 2 ng/mL threshold for lead in milk was utilized to release affected cows back into the milking herd. After 289 days of surveillance, one of the five cows under milk surveillance was yet to meet this threshold. Milk lead concentrations greater than 2 ng/mL can result in lead intakes exceeding 2.2 µg/day limits for young children in the highest milk consumption group. Lead is not routinely assessed in fluid milk as a quality control step prior to processing in the United States, yet interstate commerce justifies a need for harmonized protocols for routine lead surveillance of the general milk supply and enhanced surveillance and quarantine for known food-animal exposures. Full article

The declining trend of battery aging has strong nonlinearity and volatility, which poses great challenges to the prediction of battery’s state of health (SOH). In this research, an innovative framework is initially put forward for SOH prediction. First, partial incremental capacity analysis (PICA) is carried out to analyze the performance degradation within a specific voltage range. Subsequently, the height of the peak, the position of the peak, and the area beneath the peak of the IC curves are retrieved and used as health features (HFs). Moreover, improved ensemble empirical mode decomposition based on fractal dimension (FEEMD) is first proposed and utilized to decompose HFs to reduce the nonlinearity and fluctuations. Additionally, a bidirectional gated recurrent unit with an attention mechanism (BiGRU-AM) is constructed for the prognosis of these sub-layers. Finally, the effectiveness and robustness of the proposed prognosis framework are validated using two battery datasets. The results of three groups of comparative experiments demonstrate that the maximum root mean squared error (RMSE) and mean absolute error (MAE) values reach merely 0.55% and 0.59%, respectively. This further demonstrates that the proposed FEEMD outperforms other benchmark models and can offer a reliable foundation for the health prognosis of lithium-ion batteries. Full article

Background/Objectives: The existing literature has described the common symptoms and long-term effects of coronavirus disease (COVID-19). However, there is a lack of detailed information on how different degrees of disease severity affect survivors differently. This study aims to fill that gap by evaluating the symptoms, physical activity, and functionality of COVID-19 survivors across a spectrum of severity levels, comparing them with those of healthy individuals. Methods: An observational study was carried out following the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) criteria and checklist. Participants were divided into 5 groups based on COVID-19 severity according to the World Health Organization classification: healthy (COVID-19-negative), mild (symptomatic without pneumonia or dyspnoea), moderate (pneumonia and dyspnoea without hospitalisation), severe (severe pneumonia requiring hospitalisation), and critical (severe pneumonia with admission to the intensive care unit). Descriptive variables, symptoms (Fatigue Borg Scale, Fatigue Impact Scale, Fatigue Severity Scale, Dyspnoea Borg Scale, Visual Analogue Scale, Hospital Anxiety and Depression Scale, and European Quality of Life-5 Dimensions), physical activity (the International Physical Activity Questionnaire) and functionality (Patient-Specific Functional Scale, Short Physical Performance Battery, Arm Curl test, and 2 min step test) were measured. Results: A total of 304 participants were included: healthy (n = 42), mild (n = 143), moderate (n = 49), severe (n = 52), and critical (n = 18) COVID-19 patients. The impact of COVID-19 on surviving patients varies significantly with the severity of the disease. The results show that the hospitalisation time, age, and comorbidities of the patients are greater in those with a greater severity of the disease. Patients with more severe COVID-19 also experience greater frailty, dysphagia, fatigue, dyspnoea, and pain. Additionally, those with severe cases have poorer overall health, reduced physical activity, and diminished functionality. No evidence of post-COVID-19 anxiety or depression is found in the sample, even considering the timeframe between the negative test and the assessment. Conclusions: Patients with higher COVID-19 severity (severe or critical) experience more symptoms than those with lower COVID-19 severity (mild or moderate). Additionally, those with severe cases have poorer overall health, reduced physical activity and diminished functionality. Register: Clinicaltrials.gov: NCT05731817. Full article

Hydrogen-bonded organic framework (HOF) materials are typically formed by the self-assembly of small organic units (synthons) with specific functional groups through hydrogen bonding or other interactions. HOF is commonly used as an electrolyte for batteries. Well-designed HOF materials can enhance the proton exchange rate, thereby boosting battery performance. This paper reviews recent advancements in the continuous synthesis of HOF synthons, in the continuous synthesis of HOF’s unit small molecules enabling the multi-step, rapid, and in situ synthesis of synthons, such as carboxylic acid, diaminotriazine (DAT), urea, guanidine, imidazole, pyrazole, pyridine, thiazole, triazole, and tetrazole, with online monitoring. Continuous flow reactors facilitate fast chemical reactions and precise microfluidic control, offering superior reaction speed, product yield, and selectivity compared to batch processes. Integrating the continuous synthesis of synthons with the construction of HOF materials on a single platform is essential for achieving low-cost, safe, and efficient processing, especially for reactions involving toxic, flammable, or explosive substances. Full article

A novel mineral-like phosphate hydrate Na_6.9Ni²⁺_0.9V³⁺_4.3Al_0.8(PO₄)₈(H₂O)₂ (Z = 2) was obtained under high-temperature hydrothermal conditions by modeling the chemistry of geothermal brines in natural geological solutions. The compound, characterized by scanning electron microscopy and microprobe analysis, possesses an orthorhombic symmetry with the Cccm space group; the unit cell parameters are a = 6.4082(8), b = 19.6813(19), c = 10.5035(11) Å. Here we report its crystal structure studied by low-temperature single crystal X-ray diffraction and discussed as derived from the α-CrPO₄ archetype, known for a large range of compounds with promising properties. Three-dimensional continuous migration pathways for Na⁺ within the structure were found and confirmed by a bond valence energy landscape analysis. The migration barriers turned out to be ~0.44 eV along the a and b directions and ~0.42 eV along the c axis. These values suggest that the compound may be a potential electrode material for sodium-ion batteries. Full article

In this paper, a novel mixed Tutton salt (K_0.86Na_0.14)₂Ni(SO₄)₂(H₂O)₆ was successfully synthesized as a single crystal and evaluated as a thermochemical heat storage material. Its thermal and thermochemical properties were correlated with the structure, which was determined by powder X-ray diffraction using the Le Bail and Rietveld methods. The elemental ratio between the K⁺ and Na⁺ monovalent cations was established by energy-dispersive X-ray spectroscopy. Similar compounds such as Na₂Ni(SO₄)₂(H₂O)₄ and K₂Ni(SO₄)₂(H₂O)₆ were also synthesized and used for structural comparisons. The (K_0.86Na_0.14)₂Ni(SO₄)₂(H₂O)₆ salt crystallizes in monoclinic symmetry with the P2₁/c-space group, typical of hexahydrate crystals from the Tutton salt family. The lattice parameters closely resemble those of K₂Ni(SO₄)₂(H₂O)₆. A comprehensive analysis of the intermolecular contacts, based on Hirshfeld surfaces and 2D fingerprint mappings, revealed that the primary interactions are hydrogen bonds (H···O/O···H) and ion-dipole interactions (K/Na···O/O···Na/K). The unit cell exhibits minimal void space, accounting for only 0.2%, indicative of strong atomic packing. The intermolecular molecular and atomic packing are important factors influencing crystal lattice stabilization and thermal energy supplied to release crystallographic H₂O. The thermal stability of mixed Tutton salt ranges from 300 K to 365 K. Under the dehydration of its six H₂O molecules, the dehydration reaction enthalpy reaches 349.8 kJ/mol, yielding a thermochemical energy storage density of 1.79 GJ/m³. With an H₂O desorption temperature ≤393 K and a high energy storage density ≥1.3 GJ/m³ (criteria established for applications at the domestic level), the (K_0.86Na_0.14)₂Ni(SO₄)₂(H₂O)₆ shows potential as a thermochemical material for small-sized heat batteries. Full article

This study examines the effect of the investment portfolio structure on insurers’ solvency, as measured by the Solvency Capital Requirement ratio. An empirical sample of 88 EU-based insurance groups was analyzed to provide robust evidence of the portfolio’s impact on the Solvency Capital Requirement ratio from 2016 to 2022. Linear regression and supervised machine learning models, particularly extra trees regression, were used to predict the solvency ratios, with the latter outperforming the former. The investigation was supplemented with panel data analysis. Firm-specific factors, including, unit-linked and index-linked liabilities, firm size, investments in property, collective undertakings, bonds and equities, and the ratio of government bonds to corporate bonds and country-specific factors, such as life and non-life market concentration, domestic bond market development, private debt development, household spending, banking concentration, non-performing loans, and CO₂ emissions, were found to have an important effect on insurers’ solvency ratios. The novelty of this research lies in the investigation of the connection of solvency ratios with variables that prior studies have not yet explored, such as portfolio asset allocation, the life and non-life insurance market concentration, and unit-linked and index-linked products, via the employment of a battery of traditional and machine enhanced methods. Furthermore, it identifies the relation of solvency ratios with bond market development and investments in collective undertakings. Finally, it addresses the substantial solvency risks posed by the high banking sector concentration to insurers under Solvency II. Full article

Accurate prediction of lithium-ion batteries’ (LIBs) state-of-health (SOH) is crucial for the safety and maintenance of LIB-powered systems. This study addresses the variability in degradation trajectories by applying gated recurrent unit (GRU) networks alongside principal component analysis (PCA), Granger causality, and K-means clustering to analyze the relationships between operating conditions—such as temperature and load profiles—and battery performance degradation. This paper uses a publicly accessible dataset derived by aging three prismatic LIB cells under a realistic forklift operation profile. First, we identify the features that are relevant to driving variance, then we employ the winning algorithm of K-means clustering for the classification of operational states. Granger causality later investigates the inter-group relationships. Our GRU-BPP model achieves an RMSE value of 0.167 and an MAE of 0.129 for the reference performance testing (RPT) dataset and an RMSE of 0.032 with an MAE of 0.025 for the aging dataset, thus outperformed benchmark methods such as GRU, LME, and XGBoost. These results further enhance the predictiveness and robustness of this approach and yield a holistic solution to the conventional challenges in battery management and their remaining useful life (RUL) predictions. Full article

Background/Objectives: Multiple sclerosis (MS) is a chronic neurological disorder characterized by various clinical presentations and manifestations that include biopsychosocial impediments. This study has three interrelated goals relevant to biopsychosocial functioning: (i) compare reasoning ability, neuropsychological functioning, affective range, and quality of life (QoL) between people with multiple sclerosis (PwMS) and healthy controls; (ii) explore gender differences in reasoning ability and neuropsychological functioning, affective symptoms, and QoL among PwMS; and (iii) examine the relationship between QoL and cognitive performance in PwMS, focusing on those with inadequate vs. adequate QoL. Methods: This multicenter study was carried out among clinically stable PwMS (no relapse in the last two months) at follow-up in two tertiary care units in urban Oman. Healthy controls, matched for age and sex, were also recruited as a comparison group. Data were collected using cognitive batteries sensitive to current reasoning ability and conventional neuropsychological batteries designed to measure verbal learning, visual-spatial ability, and processing speed. The affective range (anxiety and depressive symptoms) and quality of life (QoL) were also evaluated. Results: The PwMS group scored lower on current reasoning ability, verbal learning, visual-spatial ability, and processing speed compared to the control group. The incidence of anxiety was higher in the PwMS group, but there were no statistically significant differences in depressive symptoms. No significant differences were found in cognitive variables between the two sexes, except in visual-spatial ability, where women outperformed men. PwMS with low QoL scored lower on attention and concentration indices than those with adequate QoL. According to QoL, no significant differences were observed in reasoning, verbal learning, or visual-spatial ability. Conclusions: The present sentinel study suggests that the Omani cohort with MS tends to have lower indices of current reasoning ability, visual and spatial memory, and cognitive speed compared to control subjects. Gender differences are minimal, except for visual-spatial abilities, where women outperform men. Quality of life significantly affects cognitive functioning. In general, the biopsychosocial impediment appears to be significant, indicating the need for comprehensive evaluation and care in the management of MS. Full article

Most researchers have assessed cognitive functions in post-COVID-19 patients by means of screening tools and found cognitive sequelae in addition to anxiety, stress, depression, and a reduced quality of life (QoL). This study was aimed at investigating cognitive and psychological sequelae in patients admitted to the intensive care unit (ICU) six months (t6) and one year (t12) after discharge from the hospital, the impact of critical illness on well-being and QoL, and the protective role of cognitive reserve (CR). Twenty-three ICU patients underwent an extensive neuropsychological test battery at t6 and t12; a healthy control group underwent the same evaluation. Patient scores were compared with control scores: patients reported significantly lower scores in visual–spatial functions, both at t6 (U = 122; p = 0.033) and at t12 (U = 70; p = 0.003), and higher levels of anxiety (U = 126; p = 0.043) and depression (U = 97; p = 0.005) at t6; the levels of anxiety decreased at t12, while only depression symptoms persisted (U = 99.5; p = 0.025). Regarding the QoL, patients obtained lower scores in the physical component of QoL, both at t6 (U = 72; p = 0.008) and at t12 (U = 56.5; p = 0.005). Few and moderate correlations emerged between isolated cognitive functions and CR and the length of hospital stay. The results suggest a prevalent visual–spatial involvement, the medium- and long-term persistence of psychological sequelae, and a reduced QoL in ICU patients. Full article