Browse Articles

Kinetic theory of chiral active disks: Odd transport and torque density

Parity-odd transport is a central signature of chiral fluids, yet analytical predictions are sparse. Here, we introduce a minimal two-dimensional hard-disk gas in which chirality arises solely from a collision-induced transverse impulse. Motivated by granular spinners, collisions are dissipative and inject orbital angular momentum through a fixed tangential “kick” at contact. Starting from a Boltzmann–Enskog description, we derive nonlinear hydrodynamic equations for density, momentum, and temperature and show that chirality generates an antisymmetric homogeneous stress corresponding to a nonzero torque density. In the dilute limit, a Chapman–Enskog expansion yields analytical predictions for transport coefficients, including odd viscosity, odd thermal conductivity, and odd self-diffusivity, in good agreement with numerical simulations. This minimal kinetic model can serve as a foundation for systematic coarse-graining of chiral fluids and as a tractable benchmark for gaining insight into odd transport across a broader class of chiral systems.

Erratum: “Electronic-state-resolved master equation study of energy transfer and electron-impact chemical kinetics in the nitrogen system” [J. Chem. Phys. 164, 134310 (2026)]

Interplay between capillary and dispersion forces in adhesion under ambient conditions

Measurements of adhesion force between hydrophilic rough surfaces performed at controlled humidity generated controversial results at humidity below the critical one. Measurements with adhered cantilever demonstrated roughness but not humidity dependence, while measurements with atomic force microscope (AFM) showed an important role of capillary interaction. In this paper, the controversy is resolved using the contact of a deposited Au surface with Si wafer as an example. No assumption on surface roughness is made. Instead, all necessary information is extracted from large, detailed AFM scans. Using the force balance equation, not only the adhesion force but also a realistic place-to-place variation of the force is determined. Critical new elements of the analysis are the inclusion of the long-distance dispersion force and the nominal area of contact. For small roughness, the short-distance, capillary, and long-distance dispersion forces are all proportional to the nominal area of contact as usually assumed. However, for larger roughness, the short-distance and capillary forces grow with area much slower, making the role of the dispersion force more important. An additional factor that influences the relative contribution of different forces to adhesion is the average distance at contact, which is also determined from the force balance. Very different nominal areas of contact used in the adhered cantilever and AFM measurements explain the seeming contradiction between these experiments.

Sequence-robust MRI asymmetry measures for the detection of anoperineal lesions in Crohn’s disease on axial pelvic MRI scans

Magnetic resonance imaging (MRI) is widely considered the gold standard for evaluating Crohn’s disease anoperineal lesions. However, despite its central role in clinical evaluation, automated methods specifically dedicated to the analysis of these lesions remain rare. This is particularly challenging in the context of anoperineal lesions due to (i) the diversity of MRI sequences, (ii) the small size of cohorts available to train complex models, and (iii) the absence of a standard shape for lesions. In this context, we explore an alternative strategy based on interpretable asymmetry features in axial MRIs, explicitly capturing morphological and intensity differences between the left and right sides of the perineal region. These features were used to either classify images as containing or not anoperineal lesions, or to precisely locate a lesion on an MRI slice. We apply this method on a small cohort of 44 patients affected by Crohn’s disease, including 134 sequences of MRI of various types (38 T1 sequences, 74 T2 sequences, etc). First, a proof-of-concept dataset was constructed, including images either clearly presenting lesions or not (thus excluding symmetrical lesions), to prove that the asymmetry features we compute are sensitive to the presence of asymmetric lesions on MRI images. Importantly, we were able to show that the asymmetry features are not particularly sensitive to MRI sequences’ type, or patients’ effect, even with limited annotated datasets. The classification model demonstrates promising diagnostic performance, achieving an Area Under Curve (AUC) greater than 0.85 on the proof-of-concept dataset. However, when making predictions on the validation and test dataset, the AUCs drop to 0.667 and 0.647 respectively. The model struggles to generalize to all kinds of lesions, particularly to classify lesions slices when symmetrical (horseshoe) lesions are observed. Additionally, the method designed to locate a lesion in an image exhibited good precision, with a median distance of 1 centimeter between the detected area and the actual lesion position on our proof-of-concept dataset and 1.2 centimeter on the complete dataset, indicating its potential usefulness in future studies focused on standardized assessment of anoperineal lesions.

Synergistic Bioactive Ointment: ZnO Nanoparticles Combined with Carica papaya Latex and Aloe Vera Gel for Broad-Spectrum Biomedical Applications

The development of multifunctional topical formulations that combine natural bioactives with therapeutic nanomaterials offers a promising route to improved wound healing and management. Carica papaya fruit latex powder and Aloe barbadensis Miller gel were incorporated as active ingredients into an ointment base consisting of ZnO nanoparticles, cassava starch, and white petroleum jelly to formulate a novel topical medication with enhanced biological properties. According to the 2,2-diphenyl-1-picrylhydrazyl antioxidant assay, IC 50 values of Carica papaya latex, Aloe gel, and ZnO nanoparticles were 454.54, 312.50, and 490.82 μg/mL, respectively. Carica papaya latex powder showed a protease activity of 58.40 units/mg of the solid. The ointment base exhibited the lowest blood clotting index (3.57 ± 6.09%), suggesting strong coagulation potential, whereas ZnO showed the highest (22.26 ± 1.09%), indicating minimal clotting ability under the current experimental setup. Erythrocyte adsorption was also highest in the ointment base (84.10 ± 1.09%), reinforcing its strong interaction with blood components. Cassava starch and petroleum jelly displayed moderate Red Blood Cell (RBC) attachment percentages. Platelet adhesion with the ointment base (61.55 ± 1.09%) and cassava starch (53.97 ± 2.40%) showed better platelet interaction than ZnO (29.1 ± 4.08%). Hemolysis data indicated that petroleum jelly caused the highest RBC lysis at all concentrations, while the ointment base showed the lowest activity, indicating better hemocompatibility. Clotting time analysis further highlighted the ointment base and petroleum jelly as effective pro-coagulants (13.30 s and 13.34 s, respectively), whereas ZnO (18.34 min) and cassava starch (48.34 s) exhibited delayed clotting. The ointment in which the base: active ingredient ratio is 7:3, and within, Carica papaya latex: Aloe gel ratio 1:4, shows the maximum antibacterial activity against Staphylococcus aureus and Escherichia coli . The MBC/MIC ratios of the above ointment for the two organisms were lower than 4, suggesting a bactericidal effect. The time-kill curves show a gradual reduction in bacterial survival over time, with the most significant reduction observed in the ointment with the highest proportion of Aloe vera.

Anxiety disorder burden inequalities across middle- and high-income countries: 1990–2035 trends and projections

Background Anxiety disorders are among the most common mental health conditions worldwide, but their burden varies substantially across countries with different income levels. Evidence remains limited on how anxiety disorder burden, violence-related risk factors, and future trends differ across middle- and high-income countries (MHICs). This study examined inequalities in the burden of anxiety disorders across MHICs from 1990 to 2023, quantified the burden attributable to major risk factors, and projected prevalence trends to 2035. Methods Data on incidence, prevalence, and disability-adjusted life years (DALYs) for anxiety disorders were obtained from the Global Burden of Disease 2023 database. We estimated counts, age-standardized incidence rates (ASIRs), age-standardized prevalence rates (ASPRs), and age-standardized DALY rates (ASDRs), with 95% uncertainty intervals (UIs), by income group, sex, age, country, and year. Risk-attributable DALYs were assessed for intimate partner violence (IPV), bullying victimization (BV), and sexual violence against children (SVAC). Temporal trends were evaluated using Joinpoint regression, and Bayesian age-period-cohort (BAPC) models were used to project prevalence rates to 2035. Results In 2023, MHICs accounted for 91.3% (95% UI 60.7–137.2) of global prevalent cases, 90.8% (95% UI 50.4–153.7) of incident cases, and 91.2% (95% UI 44.8–177.6) of anxiety disorder DALYs. High-income countries (HICs) had the highest ASIRs, ASPRs, and ASDRs, whereas lower-middle-income countries (LMICs) had lower rates but larger absolute numbers of cases. From 1990 to 2023, the burden increased across MHICs, with the fastest growth observed in LMICs. Females had consistently higher ASIRs, ASPRs, and ASDRs than males, and the highest burden was observed among children and adolescents. IPV, BV, and SVAC were associated with substantial anxiety disorder DALYs, with marked differences by income group, age, and sex. BAPC projections suggested that prevalence rates may continue to increase through 2035, particularly among females and in lower-income settings. Conclusions Anxiety disorder burden remains high and unequally distributed across MHICs. The burden is characterized by persistent differences by income group, sex, and age, and is associated with violence-related risk factors. These findings support the need for income-sensitive, gender-responsive, and age-targeted mental health strategies, with particular attention to prevention of violence-related risks and improved access to mental health services in lower-income settings.

Incidence and direct medical costs of child injuries in Lebanon (2012–2016): Evidence from closed insurance claims analysis

Despite the Eastern Mediterranean Region (EMR) reporting 20% of the global burden of child injury and one of the highest death rates for child injury (45.5 per 100,000), there are few studies from the region that analyze the costs of these conditions. This study provides an assessment of incidence and direct costs of child injury at hospitals in Lebanon using insurance closed claims. Historical claims data were compiled from the four largest Third-Party Administrators for health insurance companies (> 50% Lebanese insurance market share) for a period of 5 years from 2012–2016. Descriptive statistics and regression modeling were used to assess direct medical costs from hospital treatment of child injuries and to identify risk factors associated with increased costs. A total of 70,640 pediatric patients (<18 years) were treated for 87,102 unique injuries during 86,731 visits totaling $19,466,556.61 during the 5 year study period. Males accounted for almost 2/3 of injured children. Most children (86%) were treated and released from the emergency department but inpatient treatment accounted for over 50% of costs. The most commonly occurring injuries were minor (superficial soft tissue injuries, lacerations, open wounds). However, upper and lower extremity fractures, which accounted for only 7% of injuries, contributed to 28% of costs. Child injuries represent a significant direct medical cost burden in Lebanon, with inpatient treatment contributing a large proportion of expenes. Further prospective studies of child injury should evaluate cost-effectiveness of injury care and to identify opportunities for cost savings through standard treatment protocols for common conditions and injury prevention programs. Further studies are also needed to investigate the indirect and long-term costs of child injuries in Lebanon.

Bidirectional association between cognitive function and depressive symptoms in UK community elderly based on physical activity as mediator

Introduction Previous studies have shown that physical activity (PA) can improve cognitive function (CF) and depressive symptoms in middle-aged and older adults, and that there is a bidirectional relationship between the two. However, there is a lack of research on the temporal sequence and potential mechanisms of these three factors. This study conducted a large-scale longitudinal study to explore the mediating role of PA in the bidirectional association between CF and depressive symptoms in middle-aged and older adults. Methods A longitudinal study was conducted using data from the English Longitudinal Study of Aging (ELSA) collected in 2014−2015 (T1), 2016−2017 (T2), and 2018−2019 (T3). PA, CF, and depressive symptoms were assessed via questionnaires, with Spearman’s correlation analysis used to examine variable correlations. A Cross-Lagged Panel Model (CLPM) was constructed to test the longitudinal causal relationships among the three variables, and a longitudinal mediation model was developed to analyze the mediating role of PA. Results A total of 6,787 participants aged 50 years or older were included, comprising 3,777 women (55.7%) and 3,010 men (44.3%), with a median baseline age of 66 years. Spearman correlation analysis indicated a significant correlation among the three variables (r s =[−0.225, 0.447], P < 0.001). CLPM results showed that poorer CF predicted more severe depressive symptoms in the future (β T1-T2  = −0.038, P < 0.001; β T2-T3  = −0.040, P < 0.001), and more severe depressive symptoms predicted poorer future CF (β T1-T2  = −0.022, P = 0.005; β T2-T3  = −0.021, P = 0.005). The Wald test indicated that CF was the dominant factor in the bidirectional negative relationship between CF and depressive symptoms (Wald χ² = 7.546, P = 0.006). Longitudinal mediation model results showed that poorer CF at T1 predicted lower PA at T2 (β T1-T2  = 0.043, P < 0.001), and lower PA at T2 predicted more severe depressive symptoms at T3 (β T2-T3  = −0.053, P < 0.001). Bootstrap results further confirmed the significant indirect effect of T1-CF on T3-depressive symptoms through T2-PA (β = −0.002, 95% CI=[−0.004, −0.001]), with the mediation effect accounting for 5.71%. However, the indirect effect of T1-CF on T3 depressive symptoms through T2-PA was not significant (β = −0.001, 95% CI=[−0.002, 0]). Conclusion CF was negatively correlated with depressive symptoms. PA mediated the positive effect of CF on depressive symptoms in middle-aged and older adults, but failed to alleviate the negative effect of depression on CF. This study indicates that active participation in PA contributes to maintaining cognitive and mental health in middle-aged and older adults.

Supporters of Germany’s far-right AfD party are concerned about immigration rather than feeling deprived

Is concern about immigration sufficient to account for the increasing success of Germany’s right-wing populist party Alternative für Deutschland (AfD)? Or does socio-economic deprivation also matter? Using German Socio-Economic Panel (SOEP) data from 2014 to 2024, we find that concern about immigration alone accounts for about 75 percent of explicable variation in AfD support and even for 90 percent of explicable variation in voting behaviour. Therefore, variables that measure deprivation explain comparatively little additional variation in AfD support and even less variation in voting for the AfD. Previous research has shown that immigration-concern predicts AfD support. Our results extend this by arguing that the direct relationship between immigration-concern and AfD support is so strong that deprivation variables neither seem to have much additional explanatory power, nor strongly confound the direct relationship between immigration-concern and AfD support. These results undermine the much-cited “losers of modernisation hypothesis”, not only in the sense that socio-economic conditions may be a weaker explanation than cultural ones, but even by questioning whether socio-economic explanations of AfD support have much additional value over cultural explanations at all.

Identification and validation of novel reference genes for bovine respiratory and lymphoid tissues using public transcriptomes and BRSV challenge model

RT-qPCR can be employed to quantify target gene expression normalized to reference genes that are expected to remain stable across experimental conditions. However, previously reported reference genes may not be stably expressed across all experimental conditions and individuals. This research identified novel candidate reference genes from publicly available healthy bovine tissue transcriptomes and subsequently developed and validated primers for five candidate reference genes. Forty-one transcriptomes were obtained from the NCBI Gene Expression Omnibus (GEO) from apparently healthy Bos taurus samples: bone marrow, bronchial lymph nodes (LN), mesenteric LN, kidney, liver, lung, nasal epithelium, unspecified LN, spleen, thymus, and trachea. Bioinformatic analysis of each dataset was performed using FastQC, Trimmomatic, STAR, and R, with library normalization carried out using the Relative Log Expression (RLE) method and normalized gene counts converted to log2-CPM values. The values for each gene across the transcriptomes were ranked by coefficient of variation (CV). The top 200 genes ranked by CV were analyzed using RefFinder for inter-tissue stability. Five candidates were selected: DDX23, NMT1, CRNKL1, TMEM183A, and UBE2Q1. To validate stability, RT-qPCR was used to assess the stability of these genes in tissues from seven bovine respiratory syncytial virus-infected calves and two healthy calves, including lung, bronchus, trachea, nasal epithelium, tracheobronchial LN, mediastinal LN, thymus, spleen, and bone marrow. The averaged CT values were analyzed with RefFinder. Comprehensive stability values identified CRNKL1 as the most or second most stable gene in 8/10 tissues, with variation in ranking of each reference gene across all tissues. This study identified a bioinformatic workflow and candidate reference genes, with primers validated for five genes which demonstrated stability across various bovine tissues.

Acute and chronic arterial stiffness responses to stretching, aerobic, and resistance exercise: a systematic review and meta-analysis of randomized controlled trials

Global patterns and trends in heart failure burden under chronic respiratory disease cause categories among adults aged 55 years and older: A systematic analysis based on the GBD 2021 Study

Background Chronic respiratory diseases (CRDs) and heart failure (HF) impose substantial global burdens. However, the long-term population-level burden of HF impairment under CRD cause categories remains insufficiently characterized within the GBD framework. Methods Using GBD 2021 data, we estimated the prevalence and years lived with disability (YLDs) of HF impairment under CRD cause categories among adults aged ≥55 years from 1990 to 2021. CRD cause categories included chronic obstructive pulmonary disease (COPD), interstitial lung disease and pulmonary sarcoidosis (ILD&PS), and pneumoconiosis (PC). Cases, rates, relative changes, and EAPCs were used as primary descriptive measures. Joinpoint regression, age–period–cohort analysis, inequality indices, and BAPC-based projections were used as secondary analyses to describe trend timing, age–cohort patterns, socioeconomic distribution, and historical-trend extensions through 2032. Results From 1990 to 2021, the global prevalent cases and YLDs of HF impairment under CRD cause categories increased markedly, while prevalence and YLD rates changed only modestly overall. The burden rose sharply with age, especially after age 75, and was generally higher in males. Temporal trends differed across periods. Patterns varied across SDI strata and differed by CRD subtype. Model-based extensions of historical patterns suggested that this burden pattern may remain substantial through 2032. Conclusion The burden of HF impairment under CRD cause categories showed marked population-level variation across age, sex, SDI strata, and CRD subtypes. These findings may help inform burden monitoring, public health planning, resource allocation, and long-term service planning for older adults.

Introducing a recycling method for iron oxide from cold forming mild scale and its application in alkyd resin-based primer paint

Abstract Millions of tons of iron oxide-rich sludge waste are generated yearly by the steelmaking industry, posing significant environmental disposal challenges. This study aimed to develop a sustainable and economical technology by recycling this secondary material, specifically cold-forming oxide sludge, into a high-performance iron oxide pigment for use in corrosion-resistant coatings. The methodology involved a multi-stage purification process applied to the raw sludge: initial drying, separation of organic contaminants using a methanol solvent, magnetic separation to remove residual iron, and subsequent fine mechanical milling using a jet mill. The resulting powder was subjected to a crucial heat treatment at 400 ℃ to homogenize the microstructure. Finally, the refined iron oxide powder was mixed with an alkyd resin base and additives to successfully formulate a dark brown, liquid anti-rust and corrosion primer paint. The structural and chemical purity of the recovered pigment were characterized using XRD and XRF, while particle size and morphology were determined via DLS and SEM analysis, which indicated a particle size of approximately 50 to 100 nm. The performance of the final paint was rigorously validated against the ISIRI 4817 standard, employing tests such as salt spray (ASTM B117), pull-off adhesion (ASTM D4541), scratch resistance, humidity exposure, and resistance to petroleum solvents. The material characterization confirmed the successful recovery of the desired iron oxide phases (Fe 3 O 4 , Fe 2 O 3 , and Fe). The final primer paint demonstrated excellent barrier and mechanical properties, achieving a high adhesion rating (5B per ISO 2409), a satisfactory viscosity of 103.5 KU, and passing the 240-hour salt spray test with minimal defect rating. These results conclusively validate the feasibility of using waste steel sludge to produce a high-performance, anti-corrosion primer paint.

hLMR1, a hepatocyte-specific long noncoding RNA that represses amino acid catabolism through pre-mRNA interaction in human liver

Amino acid (AA) catabolism and ureagenesis in the liver are essential for maintaining systemic nitrogen homeostasis. Patients with Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD) exhibit impaired hepatic AA catabolism and urea production, accompanied by repression of genes governing these pathways. The molecular basis of this repression remains unknown. Here, we identify the hepatocyte-specific long noncoding RNA hLMR1 as a key suppressor of hepatic AA catabolism. Using a humanized liver mouse model, we show that hLMR1 knockdown broadly upregulates genes involved in AA degradation and ureagenesis. Chromatin isolation by RNA purification (ChIRP) coupled with RNA-seq reveals extensive interactions between hLMR1 and the pre-mRNAs of AA catabolism genes, mediated by a complementary motif within hLMR1 (nucleotides 587–598). In primary human hepatocytes, hLMR1 overexpression inhibits glucagon-induced activation of AA catabolic genes, whereas deletion of the 587–598 region abrogates this effect. Analysis of human liver RNA-seq datasets demonstrates a negative correlation between hLMR1 expression and AA catabolic gene programs in MASLD. Together, these findings uncover hLMR1 as a previously unrecognized regulator of hepatic nitrogen metabolism, linking lncRNA dysregulation to metabolic dysfunction in MASLD.

Machine learning-based analysis of risk factors and construction of a predictive model for hyperuricemia in Chinese health examination population

Comparing token-based and trajectory-based vowel space metrics for assessing speech in Parkinson’s disease

This study assessed the ability of three acoustic measures of vowel space, two token-based and one trajectory-based, to quantify speech differences in people with Parkinson’s disease compared to controls and correlations with speech intelligibility. Fifty-six speakers (28 people with Parkinson’s and 28 controls) read a custom reading passage containing corner vowels. For token-based measures, the triangular vowel space area (tVSA) in kHz 2 and the unitless ratio of vowel articulation index (VAI) were calculated. For the trajectory-based measure, the articulatory-acoustic vowel space (AAVS) in kHz 2 was calculated. Speakers also read five unique sentences varying in word length, which were used to collect speech intelligibility ratings. Analyses of Variance revealed that all vowel space measures yielded group differences. Binary logistic regression revealed that only the token-based measures were able to statistically discriminate PwPD from controls, however all models performed poorly (R 2  < 0.113). Linear regressions showed that token-based metrics were statistically related to intelligibility and that the VAI yielded the best model for the current sample. The results support that token-based measures are well-suited for quantifying changes in acoustic vowel space and perceived speech intelligibility in people with Parkinson’s. Future work should examine the generalizability of these findings to other motor speech disorders as well as across different speech stimuli.

d-dopachrome tautomerase promotes astrocytic cholesterol 25-hydroxylase expression through the ERK/NF-κB pathway following rat spinal cord injury

Comparative genome-wide analysis of CAD (Cinnamyl Alcohol Dehydrogenase) gene family in Medicago truncatula and Lotus japonicus and their expression profiles in response to various abiotic abiotic stresses

The CAD (Cinnamyl Alcohol Dehydrogenase) gene family is a key determinant for lignin biosynthesis in plants. In legumes, CAD enzymes are involved in the development of vascular tissues such as xylem and Casparian strip and they contribute to the production of antimicrobial and antifungal compounds. Thereby, it offers defense against pathogens and pests. Despite their biological significance, a comparative genome-wide analysis of the CAD gene family in Medicago truncatula and Lotus japonicus has not been explored. Therefore, we conducted a comparative genome-wide study to investigate the characteristics and potential role of CAD genes in these two model legume species. A total of 51 CAD genes were identified in M. truncatula ( MtCAD ) and 35 in L. japonicus ( LjCAD ). The CAD proteins are prominently characterized by ADH_N and ADH_zinc_N domains that were distributed in 8 and 6 chromosomes of MtCAD and LjCAD , respectively. Structural organization and conserved motif analysis indicated notable similarities between MtCAD and LjCAD proteins. However, considering the ancestry and functionality and based on the evolutionary analysis, LjCAD showed more similarities with Arabidopsis than MjCAD . Gene duplication analysis identified twelve duplicated gene pairs in MtCAD and eight in LjCAD, including both tandem and segmental duplication events . Most MtCAD and LjCAD were found in the cytoplasm with some of the cis -acting regulatory elements associated with stress responses. Gene Ontology annotation suggested that most MtCAD genes were associated with biological processes whereas LjCAD genes are mainly enriched in molecular functions. Both MtCAD and LjCAD showed potential roles in secondary metabolite production. Three substantial transcription factor families such as bZIP, C2H2, and ERF and several unique microRNAs were predicted to target MtCAD and LjCAD in regulating their gene expression against certain abiotic stressors for instance cold, freezing, drought, and heat. The MtCAD and LjCAD expressed highly in stress-responsive tissues such as nodule, root, immature flower, seed, and leaf. Meanwhile, RNA-sequencing data further highlighted several potential stress-responsive genes. In M. truncatula , The MtCAD1 , MtCAD3 , MtCAD9 , MtCAD15 , MtCAD23 , MtCAD27 , and MtCAD47 exhibited higher expression under cold, drought, and freezing stress compared with control conditions. Whereas in L. japonicus , LjCAD6 , LjCAD8 , and LjCAD11 showed higher expression under cold, drought, and heat stress. Thus, these genes may serve as promising candidates for improving abiotic stress tolerance and provide molecular insights into their functional roles for future crop improvement programs and experimental validation.

Anthropometric, reach jump, medicine-ball throw and lateral movement differences among elite female volleyball players: a field-based assessment

Abstract Position-specific physical and physiological characteristics differ considerably among elite female volleyball players. This study aimed to compare anthropometric, explosive power, and movement ability differences across playing positions using field-based tests. Eighty professional female players from the Chinese Volleyball League were divided into four positional groups: outside hitter/opposite (OH/OPP), middle blocker (MB), setter (S), and libero (L). Assessments included height, arm span, medicine ball throw (OH/OPP and MB only), running vertical jump reach, and lateral movement test. Data were analyzed using one‑way ANOVA or Kruskal–Wallis test with post hoc comparisons; significance was set at P  < 0.05. Significant inter‑positional differences were observed in anthropometry, jump reach, and lateral movement (all P  < 0.05). MBs were tallest with the longest arm span and fastest lateral movement. OH/OPPs showed greater upper‑body explosive power than MBs in the medicine ball throw. Discriminant analysis further supported the position‑specific nature of the physical profiles with an overall classification accuracy of 80.0%. These findings describe group‑level differences in selected field‑based measures, which may assist in position‑specific training design for Chinese elite female volleyball players.

Immediate effects of sitting position on cervical and trunk posture, perceived discomfort, and RULA-based ergonomic risk during smartphone gaming: A randomized within-subject study

Objective This study investigated the immediate effects of three sitting positions, including chair sitting with and without a backrest and cross-legged sitting on the floor, on cervical and trunk postures, musculoskeletal discomfort, and ergonomic risk during smartphone gaming among young adults. Methods A randomized within-subject study was conducted in 41 healthy participants (mean age 20.4 ± 1.1 years). Each participant played Realm of Valor (ROV) on their personal smartphone for 20 minutes in three randomly assigned sitting positions. Cervical and trunk angles were measured using two-dimensional photogrammetry at baseline and at 5, 10, 15, and 20 minutes. Ergonomic risk was assessed using the Rapid Upper Limb Assessment (RULA), with the maximum score used for analysis. After each session, participants reported perceived musculoskeletal discomfort using a visual analog scale. Results A significant interaction between time and sitting position was found for both neck flexion (F(3.87, 232.27) = 5.31, p < 0.001, partial η² = 0.081) and trunk angles (F(8,480) = 2.73, p = 0.006, partial η² = 0.044). Perceived neck discomfort was the most common symptom, with the cross-legged position showing the highest prevalence (51.2%, Cochran’s Q = 8.67, p = 0.013, Kendall’s W = 0.106). However, symptom intensity did not differ significantly among positions. RULA scores also differed across sitting positions (χ²(2) = 27.0, p < 0.001, Kendall’s W = 0.329), with the cross-legged position showing the highest score. Conclusion Sitting posture significantly affected cervical and trunk alignment, perceived discomfort, and ergonomic risk during smartphone gaming. Cross-legged sitting induced the greatest neck and trunk flexion, which may contribute to increased musculoskeletal strain over time. These findings emphasize the importance of promoting ergonomic awareness and healthy digital habits to maintain spinal alignment and reduce posture-related musculoskeletal strain; however, longitudinal studies are needed to confirm long-term effects.