Low Fatigue Research Articles

Experimental investigation on the effect of forced assembly on fatigue behavior of single-lap, countersunk composite bolted joints

Forced assembly is a common countermeasure for eliminating the interface gap during composite airframe assembly, which modifies the bolt-hole bearing behavior and brings failure risks. In this study, an experimental investigation on the effect of forced assembly on the fatigue behavior of single-lap, countersunk composite bolted joints is presented. The hole elongation and dynamic stiffness are obtained based on ASTM D6873. The S-N curves are fitted according to ASTM E739. The fatigue damage is observed through microscopy, and the residual strength is acquired by static tensile tests. The results indicate that forced assembly significantly shortens the fatigue life of joints. After forced assembly, the hole elongation evolves faster and reaches the fatigue failure threshold earlier. In addition, the initial dynamic stiffness is reduced, and the loss of stiffness is accelerated. Apart from the designed hole bearing failure, another failure mode, i.e., bolt head cracking, is observed under low fatigue load level (70% of 2% offset bearing static strength), leading to faster degradation of fatigue property. Under equal hole elongation (4% of the hole diameter), the joints with forced assembly display severe hole bearing damage, and visible shearing cracks are observed, lowering the residual strength.

Prevalence and Associated Factors of Physical Complaints Among Japanese Esports Players: A Cross-Sectional Study.

Background In the evolving landscape of electronic sports (esports), where economic and social expectations are soaring, a critical concern has emerged in physical complaints among esports players. However, empirical insights into these complaints' prevalence and influencing factors are scarce. This study aimed to determine the prevalence of physical complaints and their association with esports activities among Japanese esports players. Methodology A web-based, cross-sectional survey encompassing 175 esports players from both professional and amateur teams in Japan was conducted. The analysis focused on 79 male participants (average age: 21.6 ± 5.6 years) with complete responses. The survey items included the esports factors about the esports title mainly play (device, career duration, playing time per day on weekdays and holidays, and the distance between the screen and the face) and physical complaints (headache, neck pain, stiff or sore shoulders, wrist pain, finger pain, lower back pain, and eye fatigue). Results A total of 49.4% reported stiff or sore shoulders, 48.1% faced eye fatigue, and 30.4% had headaches. Professionals exhibited a significantly higher likelihood of neck, wrist, and lower back pain and eye fatigue than amateurs. Age-adjusted univariate logistic regression analysis uncovered that using mainly mobile devices and being closer to the screen and face were significantly associated with neck pain, stiff or sore shoulders, lower back pain, and eye fatigue. Conclusions These results suggest that poor posture caused by using mobile devices and being closer to the screen was related to various physical complaints.

Multi-Objective Optimization of the Ultrasonic Scalpel Rod and Tip with Improved Performance: Vibration Frequency, Amplitude, and Service Life

Ultrasonic scalpel design for minimally invasive surgical procedures is mainly focused on optimizing cutting performance. However, an important issue is the low fatigue life of traditional ultrasonic scalpels, which affects their long-term reliability and effectiveness and creates hidden dangers for surgery. In this study, a multi-objective optimal design for the cutting performance and fatigue life of ultrasonic scalpels was proposed using finite element analysis and fatigue simulation. The optimal design parameters of resonance frequency and amplitude were determined. By setting the transition fillet and keeping the gain structure away from the node position to enable the scalpel to have a high service life with excellent cutting performance. The frequency modulation method of setting the vibration node bosses at the node position and setting the vibration antinode grooves at the antinode position was compared. Then, the mechanism of the influence of various design elements, such as tip, shank, node position, and antinode position, on the resonance frequency, amplitude, and fatigue life of the ultrasonic scalpel was analyzed, and the optimal design principles of the ultrasonic scalpel were obtained. The proposed ultrasonic scalpel design was confirmed by simulations, impedance measurements, and liver tissue cutting experiments, demonstrating its feasibility and enhanced performance. This research introduces innovative design strategies to improve the fatigue life and performance of ultrasonic scalpels to address an important issue in minimally invasive surgery.

Effect of Gyrokinesis Exercise on Lower Extremity Edema, Balance Ability, and Fatigue in office Women Workers

OBJECTIVES This study aims to confirm the effect of Gyrokinesis exercise on lower extremity edema, balance ability, and fatigue in office women.METHODS Subjects were allocated to an exercise group (n=14) performing 60-minute Gyrokinesis sessions twice weekly for eight weeks, or a control group (n=13) wearing compression stockings during work hours. Evaluations included measuring calf and ankle circumferences for lower extremity edema, conducting single-leg stands with eyes closed and Y-balance tests for balance improvements, and administering the Fatigue Severity Scale (FSS) questionnaire to assess changes in fatigue.RESULTS First, significant reductions in ankle circumference and extracellular fluid ratio were observed in lower extremity edema. Second, while no interaction effects were found between dynamic and static balance abilities, the exercise group showed notable improvements. Third, the exercise group exhibited significant enhancements in fatigue levels.CONCLUSIONS Gyrokinesis exercise is effective in reducing lower extremity edema, improving balance ability, and reducing fatigue in office working women.

Evaluating the protective effectiveness and risk factors of ursodeoxycholic acid on COVID-19 among outpatients.

Objective: This study aimed to assess the chemopreventive effect of ursodeoxycholic acid (UDCA) against COVID-19 and to analyze infection risk factors, symptoms, and recovery in outpatients with UDCA exposure. Methods: The study enrolled outpatients prescribed UDCA from the Second Affiliated Hospital of Chongqing Medical University, China, between 01 July 2022, and 31 December 2022. Data on demographics, comorbidities, and drug combinations were collected using electronic medical records. COVID-19 infection, symptoms, severity, prognosis, vaccinations, and UDCA administration were surveyed by telephone interviews. UDCA non-users served as controls and were matched in a 1:2 ratio with UDCA users using propensity score matching with the nearest neighbor algorithm. Infection rates, symptomatology, severity, and prognosis were compared between matched and control cohorts, and risk factors and infection and recovery symptoms were analyzed in UDCA-exposed outpatients. Results: UDCA-exposed outpatients (n = 778, 74.8%) and matched UDCA users (n = 95, 74.2%) showed significantly lower SARS-CoV-2 infection rates than control patients (n = 59, 92.2%) (p < 0.05). The matched UDCA group exhibited substantially lower fever, cough, sore throat, and fatigue rates than controls (p < 0.05). Participants with UDCA exposure generally experienced mild symptoms, while those without UDCA had moderate symptoms. The matched UDCA group also had significantly shorter durations of fever and cough (p < 0.05). Risk factors such as age over 60, less than 1month of UDCA administration, diabetes mellitus, and coronary artery disease significantly increased SARS-CoV-2 infection rates (p < 0.05), while smoking led to a decrease (p < 0.05). Hypertension was associated with a prolonged COVID-19 recovery (p < 0.05), while smoking, vaccination, and fatty liver disease were associated with shorter recovery periods (p < 0.05). The main symptoms in the full UDCA cohort were fever, cough, and sore throat, with fatigue, cough, and hyposthenia being the most persistent. Conclusion: UDCA demonstrated chemopreventive effect against SARS-CoV-2 in outpatients by significantly reducing infection incidence and mitigating COVID-19 symptoms, severity, and recovery duration. Old age, short UDCA course, and comorbidities such as diabetes mellitus and CAD increased infection rates, while hypertension prolonged recovery. Smoking, vaccination, and fatty liver disease reduced infection rates and shortened recovery. UDCA had minimal impact on symptom types. Larger and longer-term clinical studies are needed further to assess UDCA's effectiveness in COVID-19 prevention or treatment.

Electromyographic Analysis of Large Muscle Activity in Progressive Collapsing Foot Deformity.

There are various deformities described in the spectrum of Progressive Collapsing Foot Deformity (PCFD) which not only have adverse effects on the foot but also on the entire lower limb. Early lower limb muscular fatigue and pain during exertion is the most common complaint of patients with PCFD. Surface electromyography (sEMG) provides an accurate assessment of muscle activity. In this study, we aim to compare the activities of quadriceps, hamstrings, and gastrosoleus muscle groups of adult patients with PCFD with normal lower limbs and correlate the radiological parameters and functional effects of PCFD with the activities. Thirty patients with bilateral PCFD and 30 controls underwent weight-bearing anteroposterior (AP), lateral, and hindfoot alignment radiographs of the foot. Radiographic parameters of PCFD were assessed. Surface electromyography was used to assess the quadriceps, hamstrings, and gastrosoleus activities, and this was compared between the 2 groups and correlated with radiological measurements of PCFD. Tegner activity questionnaire was used to assess the functional effects of collapsed arch. Electrical activities of all muscle groups were significantly higher in cases than controls. Meary's angle and hindfoot moment arm had significant correlations with hamstring activity (P = .013) and gastrosoleus activity (P = .027), respectively. Tegner scores of cases were significantly lower than those of controls (P = .041). The PCFD causes an increase in activity of large muscles of the affected lower limb which act on joints other than those in the foot. This finding may be due to several compensatory mechanisms that counteract the deforming forces. This may be a cause for the frequent complaint, early fatigue, and hence functional impairment. However, most radiological parameters did not correlate with muscle activities and larger study size may be required for further association. Diagnostic: Level 3.

Effects of laminate stacking sequence on the strength properties of aluminum alloy–carbon fiber-reinforced plastic dissimilar single-lap adhesive joints

Here, two single-lap adhesive joints (SLJs) of dissimilar materials were subjected to static and cyclic loading tests. A2017 aluminum alloy was used as an adherend for one, and carbon fiber reinforced plastic (CFRP) was used as the adherend for the other. Four types of orthogonal laminated CFRPs with different laminate stacking sequences were used as adherends to investigate the effect of adherend stiffness on the strength properties of the joints. Furthermore, the results of the finite element analysis of the dissimilar SLJs revealed that when the tensile load was applied to them, the out-of-plane deformation asymmetry increased with increasing difference in stiffness between both adherends. This asymmetry affected the peel and shear stress distributions. Furthermore, the experiments revealed that the static tensile strength of the SLJs increased with increasing stiffness of the CFRP adherend. Additionally, fracture simulation using cohesive-zone modeling (CZM) revealed that the SLJs with higher CFRP stiffness exhibited higher strength, qualitatively agreeing with the experimental results. CZM analysis and adhesion strain measurements during the tests indicated that failure occurred at the A2017 adherend–adhesive interface. In contrast, no differences were observed between the fatigue strengths of the different types of adherends in the short-life region, with a number of cycles to failure (Nf) being ≤ 2 × 105. However, in the long-life region, beyond Nf = 2 × 105, the SLJ bearing the unidirectional CFRP adherend exhibited lower fatigue strength than the others. The anodizing process on A2017 was found to improve fatigue strength by a factor of two or more.

Side Effects’ Frequency Assessment of Low Dose Oral Minoxidil in Male Androgenetic Alopecia Patients

Introduction: Hair loss is a very common complaint in dermatologists’ offices, requiring the use of proven safe and effective therapies to improve the condition without jeopardizing patients’ health and well-being. Methods: We selected 100 male patients with androgenetic alopecia beginning treatment with low dose oral minoxidil to observe incidence and frequency of side effects. Results: The side-effects/symptoms observed in the assessed patients included body and facial hypertrichosis (most incidents), lower legs edema, periorbital edema, fatigue, tachycardia, and insomnia. Dizziness, hypotension, respiratory changes, and diarrhea were expected although not found in the assessed participants. No life-threatening adverse effects were observed. Conclusion: The doses administered in current research of oral minoxidil presented good safety profile as hair loss treatment, with the most incident side-effect being related to hypertrichosis. Systemic side-effects were infrequent.

Crystal clear: How leaders and coworkers together shape role clarity and well‐being for employees in social care

AbstractWorking in social care is fraught with challenges fueled by changing policies, funding structures, societal expectations, and high relational demands, leaving employees in this sector particularly vulnerable to poor well‐being. In this study, we focus on the importance of a supportive work context—specifically coworker instrumental support and leaders' role clarity—in enabling employee role clarity, and how this can foster better mental health and reduce fatigue from ongoing changes in the sector. We ran a multilevel moderated mediation model on a sample of 270 social care employees matched with 47 leaders across two disability care organizations in Australia. Results showed that coworker instrumental support promotes role clarity, which in turn is associated with lower psychological distress and change fatigue, and higher job satisfaction. The positive relationship between coworker instrumental support and role clarity, and the subsequent relationships with well‐being, were stronger when employees had leaders who themselves had role clarity. Our findings highlight the importance of a supportive work context and role clarity as malleable levers in enabling a sustainable social care workforce and provide new theoretical and practical insights for human resource management in the social care sector.

Ultra-broad sensing range, high sensitivity textile pressure sensors with heterogeneous fibre architecture and molecular interconnection strategy

Textile-based pressure sensors have garnered extensive attentions owing to their potentials in health monitoring, human–machine interactions, wearable human–machine interfaces (HMIs) and soft robotics. High sensitivity over a broad sensing range are highly desired yet challenging for textile pressure sensors due to the incompressibility of matrix materials and the stiffening of microstructures. Herein, we developed a high performance pressure sensor based on the silk/3-Aminopropyltriethoxy-silane/titanium carbide (Silk/APTES/MXene) film. The silk is designed with heterogeneous fiber architecture, which enables rich and multi-level contact pattern and could compensate for the effect of structural stiffening. Furthermore, APTES molecules are used to enhance the interface bonding between MXene and silk, promoting the mechanical stability of the sensor. Benefiting from these advantages, the Silk/APTES/MXene sensor device is achieved with high sensitivity of 17.1 KPa−1 over an ultra-broad sensing range up to 3.3 MPa (R2 = 0.997), ultra-low detection limit (0.25 Pa), and low fatigue toughness after 5000 cycles loading and unloading. With these merits, we have demonstrated its capability for a series of human motion detection (such as foot movement detection, arm/wrist/finger bending, etc) and an overall accuracy of 95 % is obtained with the help of CNN-based convolution neural architecture. More significantly, we have built an entire intelligent human–machine dialogue system and a patient-audience dialogue system, from lip/sign language recognition to real-time screen display and final voice output.

Orientation dependence of nickel-based single crystal superalloys in VHCF regime

Aimed at research the deformation orientation in VHCF regime under different temperatures, fatigue behavior of [111]-oriented DD6 single crystal superalloy at 1000 °C and 760 °C was studied. Using the stress range criterion, the [111] orientation shows higher fatigue resistance. This difference decreases with lower stress ranges and almost vanishes near 109 cycles. In contrast, the [111] orientation has lower fatigue resistance than the [001] orientation by using the total strain range criterion. Dislocations are restricted from shearing the γ’ phase due to the lower octahedral resolved shear stress in the [111]-oriented, decreasing the deformation in γ’ phase. Combined with distinctive cross-slip behavior, this further increased the deformation along the γ-channel, significantly enhancing deformation inhomogeneity between the γ’ phase and γ-channels. At elevated temperatures, thermally activated dislocation climb and higher climb stress factor lead to a greater reduction in fatigue performance for [111] orientation at lower stress level.

Effect of peak stress and dwell time on the fatigue damage behavior of Ti-22Al-23Nb-2(Mo, Zr) alloy with lamellar microstructure

Ti2AlNb alloy is one of the candidate high strength titanium alloy materials under consideration for compressor disc, which will endure dwell loading at high peak stress level during service. In this work, low cycle fatigue (LCF) and low cycle dwell fatigue (LCDF) deformation behaviors and damage mechanism of Ti2AlNb alloy with lamellar microstructure under high loading level were investigated. The results show that fatigue life is highly dependent on the peak stress (σpeak) and dwell time (tdwell). With increasing the σpeak, the LCF life decreases gradually since higher loading stress can accelerate plastic strain accumulation and lead to faster crack propagation. When at the same σpeak, the LCDF life is lower than the LCF life due to greater plastic strain accumulation caused by dwell effect, indicating a dwell life debit of the Ti2AlNb alloy. Moreover, dwell fatigue sensitivity exhibits an increasing trend as the tdwell increases. Under different loading waveforms, the fractography shows remarkably different features. Crack source of LCF appears on sample surface, while crack source of LCDF appears on surface and sub-surface of sample. The research of LCDF behavior is relevant to aviation industry to prevent premature failure of rotating components made of Ti2AlNb alloys.

The predictive role of resilience and the ethical climate of hospital in the fatigue of surgical technologists working in operating rooms

BackgroundFatigue in surgical technologists is of paramount importance and is known as a priority because it can be regarded as a threat to the nurse’s health and patient’s safety. The fatigue level of healthcare workers can be affected by some factors, while the role of part of these factors is less known. This study aimed to determine the predictive role of resilience and the hospital ethical climate in the fatigue of surgical technologists working in operating rooms (ORs).MethodsThis is a cross-sectional study conducted on 217 surgical technologists working in ORs of hospitals affiliated with Shiraz University of Medical Sciences. Data were collected using Connor-Davidson’s Resilience scale, Olson’s Hospital Ethical Climate Survey, and the Multidimensional Fatigue Inventory, and then analyzed using Pearson’s correlation coefficient and multiple regression analysis.Results87.1% and 12.9% of surgical technologists reported low and high fatigue, respectively. All fatigue subscales had significant and negative relationships with resilience (p < 0.05). Moreover, the relationship between fatigue and ethical climate was significant (p = 0.02). The multiple linear regression model showed the predictive role of resilience in fatigue (β=-0.29, P < 0.001). According to the model, 10% of the change of fatigue was related to resilience and ethical climate.ConclusionThe present study demonstrated the relationship between resilience and ethical climate with fatigue. Moreover, resilience was a predictor of the surgical technologists’ fatigue, so that their fatigue decreased with increasing resilience. However, future studies are recommended to determine other factors influencing fatigue in surgical technologists.

Development and Evaluation of a mHealth app - (ReMiT-MS app) for Rehabilitation of Individuals with Relapsing-remitting Multiple Sclerosis - A Mixed Methods, Pragmatic Randomized Controlled Trial - Study Protocol

Background: Delaying or slowing functional loss is a valuable goal of Multiple Sclerosis (MS) rehabilitation. The mHealth app-based exercise rehabilitation intervention is expected to overcome barriers related to routine care of MS. Due to the ubiquitous presence of smartphones, they offer an excellent opportunity for remote monitoring, scheduled interaction with experts, and instruction for exercise in a home environment. Challenges in MS routine care include forgotten rehabilitation steps, limited access to local MS experts, and internal barriers such as low health literacy, mobility limitations, and fatigue, alongside external obstacles like service availability and transport costs. Objectives: To develop a mHealth app that is user-centered and context-specific for rehabilitation of MS symptoms, and to evaluate its clinical and cost effectiveness in individuals with RRMS. Methods: The proposed research will be conducted in two phases; the first phase (Phase 1a) will be focused on the development of mHealth app content (ReMiT-MS app trial I). The pilot phase (Phase 1b), where a prototype of the application will be designed, and its usability will be evaluated. Finally, in the second phase (Phase 2), the clinical and cost-effectiveness of the ReMiT-MS app for the rehabilitation of individuals with RRMS will be evaluated (ReMiT-MS app trial II). Conclusion: The findings of this proposed trial may provide a telerehabilitation platform for individuals with RRMS in a resource-limited setting and establish a low-cost healthcare delivery model. In addition, the results of this research work might open a new window in healthcare delivery in India and similar settings. Trial registration: CTRI/2022/09/045266 [Registered on 06/09/2022]

Effect of Physical Parameters on Fatigue Life of Materials and Alloys: A Critical Review

Fatigue refers to the progressive and localized structural damage that occurs when a material is subjected to repeated loading and unloading, typically at levels below its ultimate strength. Several failure mechanisms have been observed in practical scenarios, encompassing high-cycle, low-cycle, thermal, surface, corrosion, and fretting fatigue. Fatigue, connected to the failure of numerous engineered products, stands out as a prevalent cause of structural failure in service. Conducting research on the advancement and application of fatigue analysis technologies is crucial because fatigue analysis plays a critical role in determining the service life of components and mitigating the risk of failure. This study compiles data from a wide range of sources and offers a thorough summary of the state of fatigue analysis. It focuses on the effects of different parameters, including hardness, temperature, residual stresses, and hardfacing, on the fatigue life of different materials and their alloys. The fatigue life of alloys is typically high at low temperatures, but it is significantly reduced at high temperatures or under high-stress conditions. One of the main causes of lower fatigue life is residual stress. High-temperature conditions and hardfacing processes cause the development of tensile residual stresses, which in turn decreases fatigue life. But, if the hardness of the material significantly increases due to hardfacing, then the fatigue life also increases. This manuscript focuses on reviewing the research on fatigue-life prediction methods, shortcomings, and recommendations.

Laboratory investigations on influence of thermoplastic polyurethane and its hard segment content on pavement performance of asphalt mixture

ABSTRACT Thermoplastic polyurethane (TPU) is an excellent asphalt modifier, which is consisted of hard and soft segments in the TPU molecular chain. In this paper, The conventional road performances (high and low temperature performance, water stability, fatigue performance and aging resistance) of TPU modified asphalt mixture (TPU-AM) with different hard segment content were evaluated. The results proved that the hard segment of TPU can effectively improve the high temperature performance of asphalt. Compared with TPU-AM with high hard segment content, using TPU with low hard segment content as modifier, the low temperature flexibility and fatigue resistance of TPU-AM are significantly improved. TPU-AM with hard segment content of 40% has excellent high temperature performance, while the TPU-AM with hard segment content of 10% has the best fatigue ability and low temperature performance. The water stability of TPU-AM is obviously stronger than that of base asphalt mixture, although the content of TPU hard segment has little influence on the water stability of TPU-AM. The aging results show that TPU-AM has the best aging resistance when the hard segment content is 30%. Based on the above analysis, the high performance of TPU-AM can be designed by changing the hard segment content.

Socioeconomic Differences in Patient Reported Outcome Measures 3 Months After Stroke: A Nationwide Swedish Register-Based Study.

There is a well-known association between low socioeconomic status (SES), poor survival, and clinician-reported outcomes after stroke. We aimed to assess socioeconomic differences in Patient Reported Outcome Measures 3 months after stroke. This nationwide cohort study included patients registered with acute stroke in the Swedish Stroke Register 2015-2017. Patient Reported Outcome Measures included activities of daily living (mobility, toileting, and dressing), and poststroke symptoms (low mood, fatigue, pain, and poor general health). Information on SES prestroke was retrieved from Statistics Sweden and defined by a composite measure based on education and income tertiles. Associations between SES and Patient Reported Outcome Measures were analyzed using logistic regression adjusting for confounders (sex and age) and additionally for potential mediators (stroke type, severity, cardiovascular disease risk factors, and living alone). Subgroup analyses were performed for stroke type, men and women, and younger and older patients. The study included 44 511 patients. Of these, 31.1% required assistance with mobility, 18% with toileting, and 22.2% with dressing 3 months after stroke. For poststroke symptoms, 12.3% reported low mood, 39.1% fatigue, and 22.7% pain often/constantly, while 21.4% rated their general health as poor/very poor. Adjusted for confounders, the odds of needing assistance with activities of daily living were highest for patients with low income and primary school education, for example, for mobility, odds ratio was 2.06 (95% CI, 1.89-2.24) compared with patients with high income and university education. For poststroke symptoms, odds of poor outcome were highest for patients with low income and university education (eg, odds ratio, 1.79 [95% CI, 1.49-2.15] for low mood). Adjustments for potential mediators attenuated but did not remove associations. The associations were similar in ischemic and hemorrhagic strokes and more pronounced in men and patients <65 years old. There are substantial SES-related differences in Patient Reported Outcome Measures poststroke. The more severe outcome associated with low SES is more pronounced in men and in patients of working age.

Jumping with control: the interplay between psychological constructs and run-up variability in elite jumpers.

The purpose of this study was to examine the relationship between psychological aspects (emotional regulation, self-control, mood states, and perceived stress) and components of run-up variability in horizontal jumps and to conduct comparisons based on sex, events (long jump and triple jump), and contextual situations (training versus competition). A total of 10 elite-level athletes (five males and five females) with a mean age of 27.14 (±4.25) years were recruited for the study. All participants had competed nationally or internationally and had 13.10 (±3.48) years of athletic experience. Data were collected during competitions and training sessions for 5 weeks. The participants completed the Brunel Mood Scale, Emotional Regulation Questionnaire, Brief Self-Control Scale, and Visual Analogical Scale of Perceived Stress before each session. The components of run-up variability of successful and failed attempts were measured using video analysis. Data were analyzed using a t-test, Pearson's correlation, and Cohen's d. Athletes specializing in long jump and triple jump displayed similar psychological and run-up variability characteristics. However, females showed higher values for tension and depression, whereas males had higher run-up speeds and vigor. In competitions, athletes tended to have higher vigor, lower fatigue and confusion, an earlier beginning of the adjustment phase, fewer failed attempts, and higher run-up speed than during training. Emotional regulation is inversely related to depression in women during competitions, whereas higher self-control is associated with fewer failed jumps. Athletes competing in the long jump and the triple jump do not differ in psychological traits and run-up characteristics, which suggests that similar training strategies can be used in both events. However, different solutions should be used considering the sex of athletes, with a particular focus on utilizing emotion regulation tools to modulate depression in female jumpers. It is recommended to include training sessions that simulate competition demands, primarily to ensure the early onset of the run-up adjustment phase.

Low-fatigue large elastocaloric effect in NiTi shape memory alloy enabled by two-step transition

NiTi shape memory alloys are promising elastocaloric materials owing to their substantial adiabatic temperature change (ΔTad). However, the simultaneous attainment of large ΔTad and low fatigue poses challenges due to the significant hysteresis and severe functional fatigue associated with the autocatalytic avalanche-like martensitic transformation. This study demonstrates a continuous two-step transition in Ni50.8Ti49.2 (at.%), showcasing cyclic-stable superelasticity with large recoverable strain (5.9 %), substantial ΔTad (19.1 K) and high coefficient of performance. In-situ loading analysis indicates a stress-induced continuous transition from the B2 to R and subsequently to B19′. Nanoscale lattice analysis exposes heterogeneous strain network, harboring metastable R phase preceding the B19′ phase. By exploiting differences in critical stress and transformation potential between R and B19′ phases, this study demonstrates the possibilities to synergistically integrate functional performances of different martensitic phases in NiTi into a sequential and continuous two-step transition to provide controlled strain release with unprecedented properties.

Chronic venous disease of lower limbs in young men at high-altitude: A cross-sectional survey.

The aim of this study was to understand the prevalence of chronic venous disease (CVD) of lower limbs in young men at high-altitude in Xizang, and to provide prevention measures. The convenient sampling method was used to conduct a questionnaire survey among males aged 18 to 40 above an altitude of 3000meters in Xizang in April 2023. The contents of the questionnaire included basic information, symptoms of CVD of lower limbs, protection status and training needs. Multivariate logistic regression model was calculated to evaluate the risk factors for CVD. A total of 350 survey questionnaires were received, and 326 valid samples were collected. The prevalence of CVD of lower limbs (C1-C6) was 37.42% (95%CI: 32.17%-42.68%), the ratio of C0 to C5 were 62.58%, 27.30%, 3.07%, 4.60%, 2.15% and 0.31%, respectively, no one reached C6. The top three symptoms of CVD were lower limb fatigue (18.10%), heaviness (15.34%) and pain (13.19%). 46.01% of respondents were unaware of CVD, and 12.88% of respondents did not have any protective measures of CVD. Multivariate logistic regression showed that age (OR = 1.076, 95%CI: 1.018-1.137, p = .009), preference for spicy food (OR = 1.747, 95%CI: 1.083-2.818, p = .022), unbalanced diet (OR = 1.877, 95%CI: 1.049-3.358, p = .034) and physical exercise (OR 0.610, 95%CI: 0.377-0.986, p = .044) were the independent risk factors for CVD. This study provided data on the prevalence of CVD in young men at high-altitude and the risk factors for CVD. The findings of this study may facilitate the development of individualized clinical assessments and targeted prevention programs.