Quantum Spin Exchange Interactions Trigger O p Band Broadening for Enhanced Aqueous Zinc-Ion Battery Performance.

The pressing demand for large-scale energy storage solutions has propelled the development of advanced battery technologies, among which zinc-ion batteries (ZIBs) are prominent due to their resource abundance, high capacity, and safety in aqueous environments. However, the use of manganese oxide cathodes in ZIBs is challenged by their poor electrical conductivity and structural stability, stemming from the intrinsic properties of MnO2 and the destabilizing effects of ion intercalation. To overcome these limitations, our research delves into atomic-level engineering, emphasizing quantum spin exchange interactions (QSEI). These essential for modifying electronic characteristics, can significantly influence material efficiency and functionality. We demonstrate through density functional theory (DFT) calculations that enhanced QSEI in manganese oxides broadens the O p band, narrows the bandgap, and improves both proton adsorption and electron transport. Empirical evidence is provided through the synthesis of Ru-MnO2 nanosheets, which display a marked increase in energy storage capacity, achieving 314.4 mAh g-1 at 0.2 A g-1 and maintaining high capacity after 2000 cycles. Our findings underscore the potential of QSEI to enhance the performance of TMO cathodes in ZIBs, pointing to new avenues for advancing battery technology.

Inducing weak and negative Jahn-Teller distortions to alleviate structural deformations for stable sodium storage.

In the quest for efficient supercapacitor materials, manganese-based layered oxide cathodes stand out for their cost-effectiveness and high theoretical capacity. However, their progress is hindered by the Jahn-Teller (J-T) distortion due to the unavoidable Mn4+ to Mn3+ reduction during ion storage processes. Our study addresses this challenge by stabilizing the K0.5MnO2 cathode through strategic Mg2+ substitution. This substitution leads to an altered Mn3+ electronic configuration, effectively mitigating the strong J-T distortion during ion storage processes. We provide a comprehensive analysis combining experimental evidence and theoretical insights, highlighting the emergence of the weak and negative J-T effects with reduced structural deformation during electrochemical cycling. Our findings reveal that the K0.5Mn0.85Mg0.15O2 cathode exhibits remarkable durability, retaining 96.0% of initial capacitance after 8000 cycles. This improvement is attributed to the specific electronic configurations of Mn3+ ions, which play a crucial role in minimizing volumetric changes and counteracting structural deformation typically induced by the strong J-T distortion. Our study not only advances the understanding of managing J-T distortion in manganese-based cathodes but also opens new avenues for designing high-stability supercapacitors and other energy storage devices by tailoring electrode materials based on their electronic configurations.

Gray Matter Volumes Mediate the Relationship Between Disease Duration and Balance Control Performance in Chronic Ankle Instability.

The relationship between structural changes in the cerebral gray matter and diminished balance control performance in patients with chronic ankle instability (CAI) has remained unclear. This paper aimed to assess the difference in gray matter volume (GMV) between participants with CAI and healthy controls (HC) and to characterize the role of GMV in the relationship between disease duration and balance performance in CAI. 42 participants with CAI and 33 HC completed the structural brain MRI scans, one-legged standing test, and Y-balance test. Regional GMV was measured by applying voxel-based morphometry methods. The result showed that, compared with HC, participants with CAI exhibited lower GMV in multiple brain regions (familywise error [FWE] corrected p < 0.021). Within CAI only, but not in HC, lower GMV in the thalamus (ß = -0.53, p = 0.003) and hippocampus (ß = -0.57, p = 0.001) was associated with faster sway velocity of the center of pressure (CoP) in eyes closed condition (i.e., worse balance control performance). The GMV in the thalamus (percentage mediated [PM] = 32.02%; indirect effect ß = 0.119, 95% CI = 0.003 to 0.282) and hippocampus (PM = 33.71%; indirect effect ß = 0.122, 95% CI = 0.005 to 0.278) significantly mediated the association between the disease duration and balance performance. These findings suggest that the structural characteristics of the supraspinal elements is critical to the maintenance of balance control performance in individuals suffering from CAI, which deserve careful consideration in the management and rehabilitation programs in this population.

Risk factors of metatarsal stress fracture associated with repetitive sports activities: a systematic review.

Background: Metatarsal stress fracture is common in people engaged in repetitive weight-bearing activities, especially athletes and recruits. Identifying risk factors in these contexts is crucial for effective prevention. Methods: A systematic search on Web of Science, PubMed, EBSCO, SPORTDiscus, MEDLINE, and Cochrane Library was conducted and the date range for the retrieval was set from January 1984 to April 2024. Results: 32 eligible studies were selected from 1,728 related research. Anatomical and biomechanical factors, such as higher foot arch, abnormal inversion/eversion of foot, and longer metatarsal length or larger angles, relatively influence stress fracture risk. However, given that there is no standardized measurement, the results remain to be examined. Soccer is associated with fifth metatarsal fractures, while long-distance running and recruit training often lead to fractures of the second or third metatarsals. High exercise intensity, non-adaptive training, and inadequate equipment heighten fracture risk. Conclusion: This review highlights the complex interplay of anatomical, biomechanical, and sports-related factors in the risk of metatarsal stress fractures. Relatively, high arches, specific metatarsal morphologies, and foot inversion/eversion patterns are significant risk factors, particularly among athletes. Sports type also correlates with metatarsal stress fracture locations. Despite extensive research, study heterogeneity and inherent biases necessitate cautious interpretation. Comprehensive, multifactorial approaches and personalized injury prevention strategies are essential for reducing the incidence of these injuries and improving the health and performance of athletes.

Metadielectrics for high-temperature energy storage capacitors.

Dielectric capacitors are highly desired for electronic systems owing to their high-power density and ultrafast charge/discharge capability. However, the current dielectric capacitors suffer severely from the thermal instabilities, with sharp deterioration of energy storage performance at elevated temperatures. Here, guided by phase-field simulations, we conceived and fabricated the self-assembled metadielectric nanostructure with HfO2 as second-phase in BaHf0.17Ti0.83O3 relaxor ferroelectric matrix. The metadielectric structure can not only effectively increase breakdown strength, but also broaden the working temperature to 400 oC due to the enhanced relaxation behavior and substantially reduced conduction loss. The energy storage density of the metadielectric film capacitors can achieve to 85 joules per cubic centimeter with energy efficiency exceeding 81% in the temperature range from 25 °C to 400 °C. This work shows the fabrication of capacitors with potential applications in high-temperature electric power systems and provides a strategy for designing advanced electrostatic capacitors through a metadielectric strategy.

Macrophage Migration Inhibitory Factor (MIF) Upregulates CXCR7 and Contributes to Chemotherapy Resistance in Colorectal Cancer.

Colorectal cancer is one of the most common malignant tumors worldwide, with high incidence and mortality rates making it a focus of research. Chemotherapy is a primary treatment modality for colon cancer, but chemotherapy resistance severely impacts treatment efficacy. MIF has been found to promote tumor progression and resistance in various cancers. This study aims to investigate the role of MIF in chemotherapy resistance in colon cancer and its potential mechanisms, particularly through the upregulation of CXCR7 expression, affecting the metabolism and drug sensitivity of colon cancer cells. The expression levels of MIF in colon cancer tissues and its association with patient prognosis were evaluated by analyzing TCGA and HPA data. Subsequently, the expression levels of MIF in colon cancer cell lines and resistant cell lines were detected by qRT-PCR and immunohistochemistry, and the effect of MIF on oxaliplatin sensitivity was assessed. The impact of MIF on the metabolic activity of colon cancer cells was measured using a cellular energy metabolism analyzer. Further experiments explored the mechanism by which MIF affects the metabolic activity of colon cancer cells through the upregulation of CXCR7 expression, and the role of CTCF in regulating CXCR7 transcription was validated by silencing CTCF. Finally, the effect of MIF on drug sensitivity of colon cancer cells was verified in a mouse xenograft tumor model. In this study, we found that the expression of MIF in colon cancer tissues was significantly higher than in normal tissues, and high MIF expression was associated with poor prognosis in patients. The expression levels of MIF in resistant colon cancer cell lines were significantly higher than in parental cell lines, and MIF overexpression significantly increased the resistance of colon cancer cells to oxaliplatin. Conversely, silencing MIF significantly reduced the IC50 value of resistant cells and increased apoptosis. MIF overexpression significantly increased the ECAR and OCR levels of colon cancer cells, while MIF knockdown significantly reduced these metabolic indicators. Further studies indicated that MIF affects the metabolic activity of colon cancer cells by upregulating CXCR7 expression. CTCF binding peaks at the CXCR7 promoter region and luciferase activity assays indicated that CTCF regulates CXCR7 transcription, and silencing CTCF significantly enhanced the sensitivity of colon cancer cells to oxaliplatin. In vivo experiments in mice showed that MIF silencing combined with oxaliplatin treatment significantly inhibited tumor growth and increased the necrotic area of tumor tissues. In conclusion, this study reveals the crucial role of MIF in chemotherapy resistance in colon cancer through the upregulation of CXCR7 expression, with CTCF playing an important regulatory role in this process. Our findings provide new theoretical insights and potential therapeutic targets for overcoming chemotherapy resistance in colon cancer. Future research should further explore the roles of MIF and CXCR7 in other types of cancers and the potential of MIF and CXCR7 as therapeutic targets.

Balance Control Deficits are Associated With Diminished Ankle Force Sense, Not Position Sense, in Athletes with Chronic Ankle Instability.

OBJECTIVES: To compare balance control and ankle proprioception between athletes with and without chronic ankle instability (CAI). A further objective was to explore the relationship between balance control performance and ankle proprioception in athletes with CAI. DESIGN: Cross-sectional study. SETTINGS: Sports Rehabilitation Laboratory. PARTICIPANTS: Eighty-eight recreational athletes (47 CAI and 41 healthy control) were recruited. INTERVENTIONS: No applicable. MAIN OUTCOME MEASURES: Balance control performance was assessed using the sway velocity of the center of the pressure during the one-leg standing tasks. Ankle proprioception, including joint position sense and force sense, were tested using absolute error (AE) associated with joint position reproduction and force reproduction tasks in 4 directions, that is, plantarflexion, dorsiflexion, inversion, and eversion. RESULTS: Athletes with CAI performed significantly worse than those without CAI in balance control tasks. In addition, CAI athletes showed significantly worse joint position sense and force sense in all 3 movement directions tested (plantarflexion, inversion, and eversion). Correlation analysis showed that the AE of the plantarflexion force sense was significantly moderately correlated with medial-lateral sway velocity in the one-leg standing with eyes open and closed conditions (r=.372-.403, P=.006-.012), and the AE of inversion force sense was significantly moderately correlated with medial-lateral sway velocity in the one-leg standing with eyes open (r=.345, P=.018) in athletes with CAI, but the joint position sense measures were not (all P>0.05). CONCLUSIONS: Athletes with CAI showed significantly impaired balance control performance and diminished ankle proprioception. Deficit in force sense was deemed as a moderate predictor of one-leg standing balance control deficits in athletes with dominant-side injury CAI, whereas ankle position sense may be a small predictor.

Spin Symmetry Breaking-Induced Hubbard Gap Near-Closure in N-Coordinated MnO2 for Enhanced Aqueous Zinc-Ion Battery Performance.

Transition metal oxides (TMOs) are promising cathode materials for aqueous zinc ion batteries (ZIBs), however, their performance is hindered by a substantial Hubbard gap, which limits electron transfer and battery cyclability. Addressing this, we introduce a heteroatom coordination approach, using triethanolamine to induce axial N coordination on Mn centers in MnO2, yielding N-coordinated MnO2 (TEAMO). This approach leverages the change of electronegativity disparity between Mn and ligands (O and N) to disrupt spin symmetry and augment spin polarization. This enhancement leads to the closure of the Hubbard gap, primarily driven by the intensified occupancy of the Mn eg orbitals. The resultant TEAMO exhibit a significant increase in storage capacity, reaching 351 mAh g-1 at 0.1 A g-1. Our findings suggest a viable strategy for optimizing the electronic structure of TMO cathodes, enhancing the potential of ZIBs in energy storage technology.

Cerebral hemodynamics underlying ankle force sense modulated by high-definition transcranial direct current stimulation.

This study aimed to investigate the effects of high-definition transcranial direct current stimulation on ankle force sense and underlying cerebral hemodynamics. Sixteen healthy adults (8 males and 8 females) were recruited in the study. Each participant received either real or sham high-definition transcranial direct current stimulation interventions in a randomly assigned order on 2 visits. An isokinetic dynamometer was used to assess the force sense of the dominant ankle; while the functional near-infrared spectroscopy was employed to monitor the hemodynamics of the sensorimotor cortex. Two-way analyses of variance with repeated measures and Pearson correlation analyses were performed. The results showed that the absolute error and root mean square error of ankle force sense dropped more after real stimulation than after sham stimulation (dropped by 23.4% vs. 14.9% for absolute error, and 20.0% vs. 10.2% for root mean square error). The supplementary motor area activation significantly increased after real high-definition transcranial direct current stimulation. The decrease in interhemispheric functional connectivity within the Brodmann's areas 6 was significantly correlated with ankle force sense improvement after real high-definition transcranial direct current stimulation. In conclusion, high-definition transcranial direct current stimulation can be used as a potential intervention for improving ankle force sense. Changes in cerebral hemodynamics could be one of the explanations for the energetic effect of high-definition transcranial direct current stimulation.

Unlocking Spin Gates of Transition Metal Oxides via Strain Stimuli to Augment Potassium Ion Storage.

Transition metal oxides (TMOs) are key in electrochemical energy storage, offering cost-effectiveness and a broad potential window. However, their full potential is limited by poor understanding of their slow reaction kinetics and stability issues. This study diverges from conventional complex nano-structuring, concentrating instead on spin-related charge transfer and orbital interactions to enhance the reaction dynamics and stability of TMOs during energy storage processes. We successfully reconfigured the orbital degeneracy and spin-dependent electronic occupancy by disrupting the symmetry of magnetic cobalt (Co) sites through straightforward strain stimuli. The key to this approach lies in the unfilled Co 3d shell, which serves as a spin-dependent regulator for carrier transfer and orbital interactions within the reaction. We observed that the opening of these 'spin gates' occurs during a transition from a symmetric low-spin state to an asymmetric high-spin state, resulting in enhanced reaction kinetics and maintained structural stability. Specifically, the spin-rearranged Al-Co3O4 exhibited a specific capacitance of 1371 F g-1, which is 38 % higher than that of unaltered Co3O4. These results not only shed light on the spin effects in magnetic TMOs but also establish a new paradigm for designing electrochemical energy storage materials with improved efficiency.

Effects of 12-week gait retraining on plantar flexion torque, architecture, and behavior of the medial gastrocnemius in vivo.

Objective: This study aims to explore the effects of 12-week gait retraining (GR) on plantar flexion torque, architecture, and behavior of the medial gastrocnemius (MG) during maximal voluntary isometric contraction (MVIC). Methods: Thirty healthy male rearfoot strikers were randomly assigned to the GR group (n = 15) and the control (CON) group (n = 15). The GR group was instructed to wear minimalist shoes and run with a forefoot strike pattern for the 12-week GR (3 times per week), whereas the CON group wore their own running shoes and ran with their original foot strike pattern. Participants were required to share screenshots of running tracks each time to ensure training supervision. The architecture and behavior of MG, as well as ankle torque data, were collected before and after the intervention. The architecture of MG, including fascicle length (FL), pennation angle, and muscle thickness, was obtained by measuring muscle morphology at rest using an ultrasound device. Ankle torque data during plantar flexion MVIC were obtained using a dynamometer, from which peak torque and early rate of torque development (RTD50) were calculated. The fascicle behavior of MG was simultaneously captured using an ultrasound device to calculate fascicle shortening, fascicle rotation, and maximal fascicle shortening velocity (Vmax). Results: After 12-week GR, 1) the RTD50 increased significantly in the GR group (p = 0.038), 2) normalized FL increased significantly in the GR group (p = 0.003), and 3) Vmax increased significantly in the GR group (p = 0.018). Conclusion: Compared to running training, GR significantly enhanced the rapid strength development capacity and contraction velocity of the MG. This indicates the potential of GR as a strategy to improve muscle function and mechanical efficiency, particularly in enhancing the ability of MG to generate and transmit force as well as the rapid contraction capability. Further research is necessary to explore the effects of GR on MG behavior during running in vivo.

Effects of gait retraining using minimalist shoes on the medial gastrocnemius muscle-tendon unit behavior and dynamics during running.

The effects of a 12-week gait retraining program on the adaptation of the medial gastrocnemius (MG) and muscle-tendon unit (MTU) were investigated. 26 runners with a rearfoot strike pattern (RFS) were randomly assigned to one of two groups: gait retraining (GR) or control group (CON). MG ultrasound images, marker positions, and ground reaction forces (GRF) were collected twice during 9 km/h of treadmill running before and after the intervention. Ankle kinetics and the MG and MTU behavior and dynamics were quantified. Runners in the GR performed gradual 12-week gait retraining transitioning to a forefoot strike pattern. After 12-week, (1) ten participants in each group completed the training; eight participants in GR transitioned to non-RFS with reduced foot strike angles; (2) MG fascicle contraction length and velocity significantly decreased after the intervention for both groups, whereas MG forces increased after intervention for both groups; (3) significant increases in MTU stretching length for GR and peak MTU recoiling velocity for both groups were observed after the intervention, respectively; (4) no significant difference was found for all parameters of the series elastic element. Gait retraining might potentially influence the MG to operate at lower fascicle contraction lengths and velocities and produce greater peak forces. The gait retraining had no effect on SEE behavior and dynamics but did impact MTU, suggesting that the training was insufficient to induce mechanical loading changes on SEE behavior and dynamics.

Whole leg compression garments influence lower limb kinematics and associated muscle synergies during running.

The utilization of compression garments (CGs) has demonstrated the potential to improve athletic performance; however, the specific mechanisms underlying this enhancement remain a subject of further investigation. This study aimed to examine the impact of CGs on running mechanics and muscle synergies from a neuromuscular control perspective. Twelve adult males ran on a treadmill at 12 km/h, while data pertaining to lower limb kinematics, kinetics, and electromyography were collected under two clothing conditions: whole leg compression garments and control. The Non-negative matrix factorization algorithm was employed to extract muscle synergy during running, subsequently followed by cluster analysis and correlation analysis. The findings revealed that the CGs increased knee extension and reduced hip flexion at foot strike compared with the control condition. Moreover, CGs were found to enhance stance-phase peak knee extension, while diminishing hip flexion and maximal hip extension during the stance-phase, and the ankle kinematics remained unaltered. We extracted and classified six synergies (SYN1-6) during running and found that only five SYNs were observed after wearing CGs. CGs altered the structure of the synergies and changed muscle activation weights and durations. The current study is the first to apply muscle synergy to discuss the effect of CGs on running biomechanics. Our findings provide neuromuscular evidence for the idea of previous studies that CGs alter the coordination of muscle groups, thereby affecting kinematic characteristics during running.

Activation of MnO6 Units via an Interfacial Electric Field: Electron Injection into Mn t2g for Rapid and Stable Sodium Ion Storage in CeO2/MnOx.

Manganese-based oxides (MnOx) suffer from sluggish charge diffusion kinetics and poor cycling stability in sodium ion storage. Herein, an interfacial electric field (IEF) in CeO2/MnOx is constructed to obtain high electronic/ionic conductivity and structural stability of MnOx. The as-designed CeO2/MnOx exhibits a remarkable capacity of 397 F g-1 and favorable cyclic stability with 92.13% capacity retention after 10,000 cycles. Soft X-ray absorption spectroscopy and partial density of states results reveal that the electrons are substantially injected into the Mn t2g orbitals driven by the formed IEF. Correspondingly, the MnO6 units in MnOx are effectively activated, endowing the CeO2/MnOx with fast charge transfer kinetics and high sodium ion storage capacity. Moreover, In situRaman verifies a remarkably increased structural stability of CeO2/MnOx, which is attributed to the enhanced Mn─O bond strength and efficiently stabilized MnO6 units. Mechanism studies show that the downshift of Mn 3d-band center dramatically increases the Mn 3d-O 2p orbitals overlap, thus inhibiting the Jahn-Teller (J-T) distortion of MnOx during sodium ion insertion/extraction. This work develops an advanced strategy to achieve both fast and sustainable sodium ion storage in metal oxides-based energy materials.

Impact of tourniquet use on severity of snakebite envenoming in Chongqing, China: a single-center retrospective study.

OBJECTIVE: To identify risk factors associated with snakebite severity and determine whether tourniquet use can affect the severity and outcome of snakebites. METHODS: The clinical data of patients who sustained limb snakebites from 1 March 2021 to 31 October 2022 were reviewed. The patients were divided into three groups according to snakebite severity: mild (517 cases), moderate (112 cases), and severe (8 cases). We compared the clinical data of mild versus moderate to severe snakebites. Multivariate logistic regression was used to determine the independent risk factors for moderate to severe snakebites. RESULTS: The study involved 637 patients. There were statistically significant differences in age, tourniquet use, onset time, white blood cell increase, platelet decrease, creatine kinase (CK) increase, activated partial thromboplastin time shortening, and length of stay between patients with mild snakebites and those with moderate to severe snakebites. Multivariate logistic regression analysis showed that age, tourniquet use, and CK increase were independent risk factors for moderate to severe snakebites. CONCLUSION: The overall severity of snakebites in Chongqing is mild, and the prognosis is good. Age, tourniquet use, and CK increase are independent risk factors for the severity of snakebites. We do not recommend tourniquet use after snakebites in Chongqing.

Research insights into the chemokine-like factor (CKLF)-like MARVEL transmembrane domain-containing family (CMTM): their roles in various tumors.

The chemokine-like factor (CKLF)-like MARVEL transmembrane domain-containing (CMTM) family includes CMTM1-8 and CKLF, and they play key roles in the hematopoietic, immune, cardiovascular, and male reproductive systems, participating in the physiological functions, cancer, and other diseases associated with these systems. CMTM family members activate and chemoattract immune cells to affect the proliferation and invasion of tumor cells through a similar mechanism, the structural characteristics typical of chemokines and transmembrane 4 superfamily (TM4SF). In this review, we discuss each CMTM family member's chromosomal location, involved signaling pathways, expression patterns, and potential roles, and mechanisms of action in pancreatic, breast, gastric and liver cancers. Furthermore, we discuss several clinically applied tumor therapies targeted at the CMTM family, indicating that CMTM family members could be novel immune checkpoints and potential targets effective in tumor treatment.

Effects of a 12-week gait retraining program on the Achilles tendon adaptation of habitually shod runners.

PURPOSE: This study investigated the effects of a 12-week gait retraining program on the morphological and mechanical properties of the Achilles tendon (AT) during running on the basis of real-time dynamic ultrasound imaging. METHODS: A total of 30 male recreational runners who were used to wearing cushioned shoes with a rearfoot strike (RFS) pattern were recruited. They were randomized into a retraining group (RG, n = 15) and a control group (CG, n = 15). The RG group was asked to run in five-fingered minimalist shoes with a forefoot strike (FFS) pattern, and the CG group was asked to keep their strike pattern. Three training sessions were performed per week. All the participants in RG uploaded running tracks obtained through a mobile application (.jpg) after each session for training supervision. The ground reaction force, kinematics, and kinetics of the ankle joint at 10 km/h were collected using an instrumented split-belt treadmill and a motion capture system. The morphological (length and cross-sectional area) and mechanical characteristics (force, stress, strain, etc.) of AT in vivo were recorded and calculated with a synchronous ultrasonic imaging instrument before and after the intervention. Repeated two-way ANOVA was used to compare the aforementioned parameters. RESULTS: A total of 28 participants completed the training. The strike angle of RG after training was significantly smaller than that before training and significantly smaller than that of CG after training (F (1, 13) = 23.068, p < 0.001, partial η2 = 0.640). The length (F (1, 13) = 10.086, p = 0.007, partial η2 = 0.437) and CSA (F (1, 13) = 7.475, p = 0.017, partial η2 = 0.365) of AT in RG increased after training. A significant main effect for time was observed for the time-to-peak AT force (F (1, 13) = 5.225, p = 0.040, partial η2 = 0.287), average (F (1, 13) = 7.228, p = 0.019, partial η2 = 0.357), and peak AT loading rate (F (1, 13) = 11.687, p = 0.005, partial η2 = 0.473). CONCLUSION: Preliminary evidence indicated that a 12-week gait retraining program could exert a beneficial effect on AT. 57% (8/14) runners in RG shifted from RFS to FFS pattern. Although not all runners were categorized as FFS pattern after the intervention, their foot strike angle was reduced. Retraining primarily positively promoted AT morphological properties (i.e., CSA and length) to strengthen AT capability for mechanical loading.

Acute effect of foot strike patterns on in vivo tibiotalar and subtalar joint kinematics during barefoot running.

BACKGROUND: Foot kinematics, such as excessive eversion and malalignment of the hindfoot, are believed to be associated with running-related injuries. The majority of studies to date show that different foot strike patterns influence these specific foot and ankle kinematics. However, technical deficiencies in traditional motion capture approaches limit knowledge of in vivo joint kinematics with respect to rearfoot and forefoot strike patterns (RFS and FFS, respectively). This study uses a high-speed dual fluoroscopic imaging system (DFIS) to determine the effects of different foot strike patterns on 3D in vivo tibiotalar and subtalar joints kinematics. METHODS: Fifteen healthy male recreational runners underwent foot computed tomography scanning for the construction of 3-dimensional models. A high-speed DFIS (100 Hz) was used to collect 6 degrees of freedom kinematics for participants' tibiotalar and subtalar joints when they adopted RFS and FFS in barefoot condition. RESULTS: Compared with RFS, FFS exhibited greater internal rotation at 0%-20% of the stance phase in the tibiotalar joint. The peak internal rotation angle of the tibiotalar joint under FFS was greater than under RFS (p < 0.001, Cohen's d = 0.92). RFS showed more dorsiflexion at 0%-20% of the stance phase in the tibiotalar joint than FFS. RFS also presented a larger anterior translation (p < 0.001, Cohen's d = 1.28) in the subtalar joint at initial contact than FFS. CONCLUSION: Running with acute barefoot FFS increases the internal rotation of the tibiotalar joint in the early stance. The use of high-speed DFIS to quantify the movement of the tibiotalar and subtalar joint was critical to revealing the effects of RFS and FFS during running.

High Flux and Stability of Cationic Intercalation in Transition-Metal Oxides: Unleashing the Potential of Mn t2g Orbital via Enhanced π-Donation.

Transition-metal oxides (TMOs) often struggle with challenges related to low electronic conductivity and unsatisfactory cyclic stability toward cationic intercalation. In this work, we tackle these issues by exploring an innovative strategy: leveraging heightened π-donation to activate the t2g orbital, thereby enhancing both electron/ion conductivity and structural stability of TMOs. We engineered Ni-doped layered manganese dioxide (Ni-MnO2), which is characterized by a distinctive Ni-O-Mn bridging configuration. Remarkably, Ni-MnO2 presents an impressive capacitance of 317 F g-1 and exhibits a robust cyclic stability, maintaining 81.58% of its original capacity even after 20,000 cycles. Mechanism investigations reveal that the incorporation of Ni-O-Mn configurations stimulates a heightened π-donation effect, which is beneficial to the π-type orbital hybridization involving the O 2p and the t2g orbital of Mn, thereby accelerating charge-transfer kinetics and activating the redox capacity of the t2g orbital. Additionally, the charge redistribution from Ni to the t2g orbital of Mn effectively elevates the low-energy orbital level of Mn, thus mitigating the undesirable Jahn-Teller distortion. This results in a subsequent decrease in the electron occupancy of the π*-antibonding orbital, which promotes an overall enhancement in structural stability. Our findings pave the way for an innovative paradigm in the development of fast and stable electrode materials for intercalation energy storage by activating the low orbitals of the TM center from a molecular orbital perspective.

Effects of Barefoot and Shod Conditions on the Kinematics and Kinetics of the Lower Extremities in Alternating Jump Rope Skipping-A One-Dimensional Statistical Parameter Mapping Study.

PURPOSE: To explore the difference in the biomechanics of the lower extremity during alternating jump rope skipping (AJRS) under barefoot and shod conditions. METHODS: Fourteen experienced AJRS participants were randomly assigned to wear jump rope shoes or be barefoot (BF) during the AJRS at a self-selected speed. The Qualisys motion capture system and Kistler force platform were used to synchronously collect the ground reaction forces and trajectory data of the hip, knee, ankle, and metatarsophalangeal (MTP) joints. One-dimensional statistical parameter mapping was used to analyze the kinematics and kinetics of the lower extremity under both conditions using paired t-tests. RESULTS: Wearing shoes resulted in a significant decrease in the ROM (p < 0.001) and peak angular velocity (p < 0.001) of the MTP joint during the landing phase. In addition, the MTP joint power (p < 0.001) was significantly larger under shod condition at 92-100% of the landing phase. Moreover, wearing shoes reduced the peak loading rate (p = 0.002). CONCLUSION: The findings suggest that wearing shoes during AJRS could provide better propulsion during push-off by increasing the MTP plantarflexion joint power. In addition, our results emphasize the significance of the ankle and MTP joint by controlling the ankle and MTP joint angle.