Search Results (1,127)

In recent years, alternative recycling approaches such as melt quenching and electrochemical evaluation methods have been investigated to assess the quality and performance of recovered lead materials. In this study, several samples obtained from the recycling process were analyzed electrochemically. The objective was to compare their electrochemical parameters and identify the samples with better electrochemical performance. The main methods used in this paper are X-ray diffraction analysis and voltammetric investigations using cyclic voltammetry (CV), linear sweep voltammetry (LSV), and electrochemical impedance spectroscopy (EIS). Electrochemical characterization provides valuable information about the behavior of recycled lead materials. Parameters such as half-wave potential (E_1/2), anodic current density (I_a), and solution or bulk resistance (R_b) are commonly used to evaluate electrochemical activity and conductivity. The electrochemical analysis reveals noticeable differences among the samples studied. The analysis of CV, LSV, and EIS indicates that the samples P2 (doped with CuO and Sb₂O₃) and P3N (doped with CaO/Fe₂O₃/Fe) exhibit the most favorable electrochemical behavior for lead acid battery applications, with the highest current response and smallest peak separation, suggesting efficient Pb/PbSO₄ redox reactions and minimal polarization. Full article

Background: Intraoperative blood pressure variability (BPV) is associated with adverse perioperative outcomes, although the prognostic meaning of variability itself, once blood pressure level is accounted for, remains uncertain. Preoperative metabolic indicators have not been examined in relation to intraoperative BPV. The triglyceride-glucose (TyG) index, a surrogate marker of insulin resistance, is associated with arterial stiffness in community populations. We examined whether the preoperative TyG index is associated with intraoperative BPV in surgical patients, and whether an estimated pulse wave velocity (ePWV) surrogate statistically accounts for part of this association. Methods: This single-center retrospective cohort study included 7081 adults who underwent elective major abdominal surgery under general anesthesia for at least 120 min at Beijing Tsinghua Changgung Hospital between January 2016 and December 2022. The primary outcome was the coefficient of variation of intraoperative mean arterial pressure (CV-MAP). ePWV was calculated from age and preoperative mean arterial pressure (MAP) and is therefore a surrogate rather than a direct measure of arterial stiffness. Multivariable linear regression assessed the TyG-CV-MAP association; models excluding and including age are reported as co-primary analyses. Exploratory mediation analysis using the Baron-Kenny framework with 5000 bootstrap iterations estimated the proportion of the association statistically accounted for by ePWV. Subgroup analyses tested age as an effect modifier, and a sensitivity model additionally adjusted for antihypertensive and antidiabetic medication use. Results: After adjustment for sex, body mass index, comorbidities, surgical duration, American Society of Anesthesiologists physical status, and surgery type, each unit increase in the TyG index was associated with a 0.0128-unit increase in CV-MAP (95% confidence interval [CI], 0.0097 to 0.0158; p < 0.001); with age additionally included, the estimate was 0.0086 (95% CI, 0.0056 to 0.0117; p < 0.001). In absolute terms, each unit increase in TyG corresponded to a 1.074 mmHg higher standard deviation of intraoperative MAP (MAP-SD; 95% CI, 0.842 to 1.305), against a cohort mean MAP-SD of 12.0 mmHg. ePWV statistically accounted for approximately one quarter to one third of the total effect (indirect effect, 0.0038; bootstrap 95% CI, 0.0030 to 0.0046). The association was present in patients younger than 65 years (β = 0.0132, p < 0.001), with no evidence of an association in those aged 65 years or older (β = 0.0008, 95% CI, −0.0054 to 0.0071; p = 0.79; interaction β = −0.0124, 95% CI, −0.0187 to −0.0061; p < 0.001). Sensitivity analyses supported the robustness of these findings, including a model adjusted for antihypertensive and antidiabetic medication use (β = 0.0128, 95% CI, 0.0098 to 0.0159; p < 0.001). Conclusions: The preoperative TyG index was independently associated with greater intraoperative BPV in major abdominal surgery, with the association present in patients younger than 65 years but not in older patients. An ePWV-based surrogate statistically accounted for approximately one quarter to one third of this association; because ePWV is derived from age and blood pressure rather than measured directly, this proportion may reflect the structure of the surrogate rather than a causal arterial-stiffness pathway. The clinical significance remains uncertain given the modest incremental predictive contribution and the absence of clinically anchored endpoints; prospective validation with directly measured pulse wave velocity is required. Full article

Background/Objectives: Gastrointestinal dysmotility (GID) is a frequent non-motor manifestation of Parkinson’s disease (PD). However, its peripheral electrophysiological characteristics, as well as the underlying neural mechanisms within the brain–gut axis, remain insufficiently understood. This study aimed to delineate spatiotemporal abnormalities in gastrointestinal pacing activity in PD and to explore their associations with cerebral functional connectivity (FC). Methods: Multichannel electrogastroenterography (EGEG) recordings, including both preprandial and postprandial states from gastric (leads 1–4) and intestinal (leads 5–8) regions, were obtained from patients with PD and healthy controls (HCs), alongside resting-state functional MRI (rs-fMRI). The striatal–thalamic circuit was selected as the seed region for FC analysis. Between-group differences in EGEG-derived spatiotemporal metrics were assessed using analysis of covariance (ANCOVA), while FC differences were examined using two-sample t-tests. Partial correlation analyses were conducted to evaluate associations among neuroimaging measures, aberrant gastrointestinal electrophysiological indices, and clinical variables. Regional specificity of correlations was further tested by comparing dependent correlation coefficients. In addition, multivariate brain–gut connectivity was assessed using partial canonical correlation analysis (pCCA) with 1000 permutation tests. Results: Relative to HCs, PD patients exhibited a significant reduction in the proportion of normal slow waves in both gastric and intestinal regions during preprandial and postprandial states (pFDR < 0.05). FC analysis revealed increased connectivity between the left thalamus and right insula in PD, whereas interhemispheric connectivity of the caudate nuclei and putamina was significantly reduced. Additionally, FC between the left pallidum and left precentral gyrus was attenuated in the PD group. Partial correlation analysis demonstrated a positive association between postprandial normal slow-wave fraction and interhemispheric caudate connectivity (r = 0.63, pFDR = 0.047). Furthermore, left thalamus–right insula connectivity correlated with both total Non-Motor Symptoms Scale (NMSS) scores (r = 0.57, pFDR = 0.042) and gastrointestinal subscale scores (r = 0.63, pFDR = 0.037). At the multivariate level, pCCA revealed a strong association between lentiform nucleus connectivity and preprandial gastric slow-wave rhythms (canonical r = 0.892, p = 0.004). Conclusions: In PD, caudate nucleus FC shows a preferential association with gastric rather than intestinal electrophysiological activity. Multivariate analyses further demonstrate a significant network-level association between lentiform nucleus connectivity and baseline gastric pacing rhythms, extending regional findings to a broader network interaction. Together, these results provide multimodal correlational evidence reflecting parallel central and peripheral alterations in PD, highlighting synchronized alterations in central networks and peripheral gastrointestinal rhythmicity. Full article

Background: Rural older women in China face intersecting disadvantages including eroded family support, limited pension coverage, and high social isolation that elevate depressive symptoms. Although Long-Term Care Insurance (LTCI) has expanded rapidly since 2016 to provide both financial protection and formal care services for older adults, whether it can compensate for depleted informal support and protect mental health among this vulnerable population remains unknown. Methods: We used five waves of CHARLS (2011–2020) with 2193 rural women aged ≥60. We employed a staggered difference-in-differences design, complemented by moderation analysis, heterogeneity tests, and time-dependent survival analysis. Robustness checks included Callaway-Sant’Anna DID, placebo permutation and baseline exclusion sensitivity. Results: LTCI reduced depression scores by 0.45 points (β = −0.447, p = 0.028) and depression onset hazard by 36.1% (HR = 0.639, p = 0.009). Benefits were compensatory, concentrated among women lacking regular emotional and financial support from children and those with high social isolation. Heterogeneity analyses demonstrated a pronounced age gradient and a significant education gradient, while care-need and disability subgroups showed directionally consistent but underpowered effects. These findings were robust to supplementary sensitivity checks, including Callaway-Sant’Anna DID, placebo permutation, and baseline-depressed exclusion. Conclusions: LTCI confers meaningful mental health protection for rural older women through compensatory pathways that substitute for depleted informal support. However, benefits are concentrated among younger-old and more-educated women, raising equity concerns. Gender-sensitive implementation with mental health screening, targeted outreach for less-educated women, and community-based enrollment assistance is essential to ensure policy equity. Full article

Accurate and scalable estimation of rock shear strength parameters is essential for remote-sensing-supported geological hazard assessment, slope stability evaluation, and engineering geological mapping. However, determining cohesion and internal friction angle requires multiple triaxial tests under different confining pressures, which are time-consuming, costly, and difficult to apply widely. To support remote-sensing-oriented geoscience and civil engineering applications, this study develops a hybrid machine learning framework for estimating cohesion and internal friction angle from geophysical and mechanical indicators. A cross-source database was compiled from published rock records collected from the Jinchuan mining area in China and the Luhri area in India. After completeness screening and unit harmonization, 213 mixed-lithology cases were retained for modeling, with P-wave velocity, density, uniaxial compressive strength, and tensile strength used as input variables. An Equilibrium Optimizer was coupled with a multilayer perceptron to optimize the network weights and biases, and model performance was evaluated using five-fold cross-validation, independent testing, repeated runs, and comparisons with conventional MLP and several typical machine learning models. The proposed EO–MLP model achieved high prediction accuracy, with test-set coefficient of determination values of 0.946 for internal friction angle and 0.983 for cohesion and corresponding RMSE values of 1.072 and 0.671, respectively. Robust scaler normalization produced the best performance among the three tested normalization strategies. SHapley Additive exPlanations analysis indicated that density was the dominant predictor of cohesion, whereas uniaxial compressive strength and P-wave velocity made the largest contributions to internal friction angle prediction. The proposed framework provides an indirect data-driven tool for estimating shear strength parameters and can complement engineering-geological investigation and rock engineering design. Full article

In the field of long-distance partial discharge (PD) detection for submarine cables, there is an urgent need for a remote demodulation distributed detection technology deployable at multiple critical locations to overcome the limitations of single-point measurement. Factory joints of high-voltage submarine cables are high-risk components for PD, and long-distance fiber optic acoustic sensing technology holds the greatest potential for online monitoring. However, due to the viscoelasticity of the joint’s polymer insulation structure, sound propagation distance is severely limited, and non-multi-point measurement cannot achieve effective coverage of the measurement area. This paper proposes a quasi-distributed remote demodulation sensing system, in which both the fiber optic interferometer and the distributed feedback fiber laser (DFB-FL) serve as sensors, enabling highly sensitive quasi-distributed PD detection. The DFB-FL itself is highly sensitive to strain, and the multiple fiber coils formed by the interferometer arms are also highly sensitive to strain. Both can be modulated by the micro-strain induced by the acoustic field generated from PD in the polymer solid, producing phase shifts of the optical waves, which are then intrinsically demodulated by the interferometer system to extract the vibration signals caused by the discharge. Theoretical analysis shows that the sensitivity increases with the length of the unbalanced arm, with the upper limit constrained by laser coherence and optical attenuation; for the PD frequency band, the optimal unbalanced length is below 200 m—this design rule is applicable to on-chip interferometric sensors. The interferometer coils employ bend-insensitive fibers to suppress optical loss and improve fringe visibility. Meanwhile, three fiber coil configuration schemes are constructed to enhance the detection sensitivity to acoustic signals. Simulation results generate frequency response contour maps based on Young’s modulus, indicating that the solid-wound coil achieves the highest amplitude and the broadest bandwidth, with an optimal response frequency of approximately 50 kHz. Experimental results demonstrate that among the three structure types, the solid-wound coil also achieves the largest response ratio. Finally, in tests performed on a 220 kV submarine cable intermediate joint (with the system installed inside the metallic sheath), the minimum detectable discharge level in the DFB-FL region reached 6.75 pC, while that for the fiber coil reached 12.66 pC; when installed outside the metallic sheath, the minimum detectable discharge levels were 53.2 pC for the grating region and 89.6 pC for the fiber coil. Full article

Background: Patients with type 2 diabetes (T2D) frequently exhibit impaired erythrocyte deformability, which contributes to microvascular dysfunction. We previously reported that imeglimin, a mitochondrial-targeted antidiabetic agent, prolongs erythrocyte lifespan. This study investigated the effects of imeglimin on whole-blood fluidity and its clinical implications in patients with T2D. Methods: This post hoc analysis of the INFINITY study included 25 patients with T2D who completed 6 months of imeglimin treatment (2000 mg/day) followed by a 3-month follow-up. Whole-blood fluidity was assessed by measuring whole-blood passage time using a microchannel array flow analyzer (MC-FAN). Hematological parameters, glycemic markers, and vascular indices, including brachial-ankle pulse wave velocity (baPWV) and toe-brachial index (TBI), were also assessed. Results: Whole-blood fluidity, assessed by 3-month averages of whole-blood passage time, showed an improvement trend at Months 1–3 (p = 0.058) and a significant improvement at Months 4–6 (p = 0.016) compared with baseline; this effect was reversed after discontinuation. Erythrocyte lifespan significantly increased by 10–20% during treatment and remained prolonged after discontinuation. Conversely, red blood cell count, hemoglobin, and hematocrit decreased during treatment and returned toward baseline post-discontinuation. At Month 6, baPWV increased, and TBI decreased, both showing reversibility after treatment cessation. Conclusions: In this exploratory post hoc analysis, imeglimin treatment was associated with reduced whole-blood passage time measured using the MC-FAN system, suggesting improved whole-blood fluidity in patients with T2D. The clinical and mechanistic significance of this observation requires confirmation in future controlled prospective studies incorporating direct assessments of erythrocyte rheology and microvascular function. Full article

Background: Shear wave elastography (SWE) and myotonometry are commonly used to assess muscle stiffness, but they reflect different aspects of tissue mechanics. SWE allows layer-specific evaluation, whereas myotonometry captures the response of a broader tissue complex. The contribution of individual layers to MyotonPRO-derived stiffness remains unclear. This study examined the relationship between MyotonPRO stiffness and layer-specific SWE measurements in the tibialis anterior muscle. Methods: In this cross-sectional study, 56 healthy adults were evaluated. Muscle stiffness was assessed using MyotonPRO and SWE across three regions of interest: superficial tissues including skin, subcutaneous tissue, and deep fascia (ROI 1); muscle tissue excluding fascia (ROI 2); and a composite region including all tissues from the skin surface to a depth of 2 cm (ROI 3). Relationships were analyzed using Spearman correlation, multiple linear regression, and Bland–Altman analysis. Results: Moderate but consistent correlations were observed between MyotonPRO stiffness and SWE values in ROI 2 (ρ = 0.516, p < 0.001) and ROI 3 (ρ = 0.550, p < 0.001), whereas no significant association was found in ROI 1. SWE values in ROI 2 and ROI 3 were significant predictors of MyotonPRO stiffness, explaining 38% of the variance. Bland–Altman analysis demonstrated moderate agreement with a systematic bias toward higher MyotonPRO values. Conclusions: MyotonPRO-derived stiffness reflects a composite mechanical response of muscle and surrounding tissues, with the strongest associations observed in regions encompassing both muscle and fascia. These findings highlight the importance of tissue composition and ROI selection in stiffness assessment and may facilitate more accurate interpretation of MyotonPRO measurements in musculoskeletal diagnostics and rehabilitation. Full article

Liquid crystal (LC) is a key enabling technology for continuously phase-reconfigurable microwave devices, offering analogue-tuning capabilities distinct from discrete alternatives such as MEMS and p-i-n diodes. However, the insertion loss of LC-based phase shifters is inevitably influenced by conductor surface roughness—a factor often neglected in idealised simulations. This paper presents, for the first time, a rigorous numerical quantification of how metal surface roughness affects the insertion loss and phase shift of a 60 GHz LC-filled coaxial delay line (0–180° phase shifter) with radial conductor surfaces instead of conventional planar ones. Using full-wave finite-element simulations incorporating Groisse’s phenomenological model and Huray’s snowball model, four surface configurations are analysed at 54–66 GHz: perfectly smooth conductors, roughness on both inner and outer conductors simultaneously, and roughness applied to each conductor individually. Results show that roughness induces a measurable increase in insertion loss—worst when both conductors are rough—but its impact on differential phase shift remains minimal (<0.32°). Huray’s model predicts conductor losses 1.77 times higher than Groisse’s model, yielding more conservative metrics. For the insertion loss evaluation in Case 2 at 60 GHz under the reference isotropic LC state, Groisse’s model predicts 1.90921 dB, while Huray’s model predicts 2.16319 dB, a 0.25 dB discrepancy (12% uncertainty relative to the mean). The inner conductor dominates roughness-induced losses due to concentrated current density, suggesting prioritised surface finishing of the core line. This study isolates loss mechanisms in a coaxial LC structure, providing insights into low-loss reconfigurable devices. Practical PCB copper foil fabrication methods are also evaluated with quantitative analysis of non-ideal cylindrical geometries. Full article

Bacterial fluorescence generated by endogenous fluorophores may provide an optical approach for monitoring microbial fluorescence responses. The aim of this study was to analyse temporal changes in the Hue parameter, defined as an image-derived component of the HSB colour space representing the dominant colour tone, and to characterize strain-associated fluorescence response profiles under 405 nm violet-light excitation. A total of 28 reference bacterial strains were examined. Each strain was inoculated at eight distinct locations on a separate BHI agar plate, yielding eight colonies per strain. At 24, 48, 72, 96, and 168 h of incubation, the same colonies were repeatedly exposed for 45 s to a 405 nm continuous-wave diode laser operating at 200 mW and imaged in a completely darkened room using an iPhone 14, a yellow emission filter, and fixed acquisition geometry. The JPEG images were converted to the HSB colour space in ImageJ software (version 1.54), and background-corrected Hue values were calculated for each colony as ΔHue = Hmean − Hmean_BG using the corresponding colony and agar-background regions of interest. A complementary qualitative visual assessment was performed, and aligned rank transform ANOVA was used to evaluate the effects of bacterial strain, incubation time, and their interaction. ΔHue values differed significantly between strains and across incubation time points, with significant strain × time interactions observed in both rod-shaped and coccal bacteria (all p < 0.001). Exploratory planned contrasts also showed differences between the predefined Gram-staining groups (p = 0.0002) and between rod-shaped and coccal bacteria (p < 0.0001); however, these comparisons do not establish independent effects of Gram status or cellular morphology. The recorded fluorescence signal was generally weak, although visible temporal changes occurred in selected strains, including Staphylococcus aureus ATCC 6538P and Proteus mirabilis PCM 543. Overlap between ΔHue distributions limited separation of some strains. Background-corrected Hue analysis enabled exploratory within-dataset monitoring of temporal fluorescence colour changes under the applied in vitro imaging protocol. However, the overlap between ΔHue distributions and the technical limitations of the imaging system preclude the use of ΔHue as a standalone bacterial identification or diagnostic parameter. Full article

Background: This study aimed to evaluate the clinical utility of shear wave elastography (SWE) in assessing abscess wall stiffness and its potential contribution to predicting the need for surgical intervention in patients with tubo-ovarian abscess (TOA). Materials and methods: This prospective cross-sectional study included 34 women diagnosed with TOA who underwent SWE evaluation upon admission. Demographic characteristics, laboratory parameters, abscess size, abscess wall elasticity, and abscess content elasticity were recorded. These patients were categorized as either medically managed or surgically treated. Group comparisons, receiver operating characteristic (ROC) curve analysis, and multivariable binary logistic regression were performed to identify independent predictors of surgical intervention. Results: There were no significant differences between the operated and non-operated groups regarding age, body mass index, and laboratory parameters (p > 0.05). The median length of hospital stay was significantly longer in the operated group (15 vs. 12 days, p = 0.017). Abscess diameter was significantly larger in the operated group (6.75 ± 1.17 cm vs. 4.65 ± 1.20 cm; p = 0.001). Likewise, the median abscess wall SWE value was significantly higher in the operated group (3.12 vs. 1.47 kPa; p = 0.027). The optimal cut-off value for abscess wall SWE was 2.04 kPa (AUC: 0.721, 95% CI: 0.551–0.892, sensitivity: 64.7%, specificity: 70.6%). Abscess size demonstrated a higher predictive performance (AUC: 0.905, 95% CI: 0.796–1.000). However, in the multivariable logistic regression analysis, only abscess size remained an independent predictor of surgical intervention (OR: 4.14, 95% CI: 1.50–11.39, p = 0.006), whereas abscess wall SWE and baseline C-reactive protein were not independently associated with treatment failure. Conclusions: Increased abscess wall stiffness measured by SWE was associated with the need for surgical intervention in patients with TOA. Although SWE was not an independent predictor after adjustment for abscess size and baseline C-reactive protein, it may serve as a complementary imaging biomarker when interpreted together with established clinical, laboratory, and conventional ultrasonographic findings. Full article

Background: The preservation of intrinsic capacity (IC) is a global public health priority, and digital health technologies offer promising avenues for managing functional decline. However, the longitudinal impact of specific smart monitoring devices on IC trajectories remains underexplored, and theoretical debates persist regarding whether digital interventions exacerbate health inequalities (the “digital divide”) or mitigate them (the “compensatory effect”). Methods: Using a balanced panel of 2432 older adults from the China Longitudinal Aging Social Survey (CLASS 2020–2023), we conducted wave-specific latent profile analyses based on five standardized WHO intrinsic-capacity domains. Modal class assignment and cross-wave profile matching were subsequently used to describe profile stability and transitions. The longitudinal protective association of baseline smart blood pressure (BP) monitor use with IC trajectories was evaluated using multinomial logistic regression with Inverse Probability Weighting (IPW). Exploratory structural path analysis was conducted to examine a potential mediating pathway. Results: The baseline latent profile analysis identified three profiles: Robust Capacity (80.2%), Cognitively Impaired (10.9%), and Sensory Impaired (8.8%). The Sensory Impaired class exhibited strong path dependence, with 62.79% of participants remaining in the same state over three years. Baseline estimates revealed that smart BP monitor usage was significantly associated with a reduced relative risk of transitioning into or remaining in the Sensory Impaired profile (RRR = 0.557, 95% CI: 0.325–0.955). The IPW analysis yielded a directionally consistent estimate (RRR = 0.696), although the association was attenuated and was not statistically significant (p = 0.162). Subgroup and pathway analyses yielded non-significant but suggestive findings, indicating that protective associations might be concentrated among vulnerable groups, particularly women and individuals with lower educational attainment. Conclusions: Smart physiological monitoring interventions demonstrate a longitudinal protective association against the persistence of physical frailty. Rather than definitively bridging the digital divide, targeted medical-grade digital tools may serve as compensatory resources for specific vulnerable subpopulations. These observational associations highlight the need for further quasi-experimental testing before integrating specific digital interventions into community-based chronic care ecosystems. Full article

Single-electron capture in the collisions of carbon ions, ${\mathrm{C}}^{q+}$ (q = 1–6), with water molecules is theoretically investigated using the continuum distorted wave-eikonal initial state (CDW-EIS) formalism. The projectile–electron interaction is modeled using three different approaches to account for screening effects: (i) the Green–Sellin–Zachor (GSZ) potential, which combines long-range Coulomb and short-range screening terms; (ii) a modified GSZ-$Z_P^r$ variant employing an effective radius-dependent nuclear charge; and (iii) the binding energy screening (BES) approximation, which treats the projectile as a rigid Coulomb core. Total cross-sections for single-electron capture are computed over the energy range of 40 keV/u to 10 MeV/u. A detailed analysis is presented as a function of the initial molecular orbital, the final bound state of the captured electron, and the projectile charge state q. The results reveal strong dependencies on orbital binding energies and the degree of projectile ionization. Additionally, of radiobiological interest, the average binding energy for the different projectiles are computed using the presented cross-sections and reported. Full article

Operational marine buoys provide essential in situ wind observations, but platform attitude variations induced by wind–wave forcing can affect wind-speed measurement quality. Existing high-frequency motion-correction methods are difficult to apply to routine buoy archives that contain only averaged outputs. This study analyzed 6964 quality-screened half-hourly observations from an operational 10 m buoy in the Changjiang Estuary (7 July–1 December 2025) and developed a Motion Impact Index (MII)-based quality classification framework for buoy wind-speed measurements under attitude and sea-state variations. The composite tilt angle was right-skewed (mean 10.68°, 95th percentile 23.09°) and significantly correlated with significant wave height ($r$ = 0.388, $p$ < 0.001). Theoretical cosine-response analysis indicated a geometric projection effect of −1.7% at the mean tilt and about −8% at the 95th percentile, whereas wind-direction dispersion showed no significant attitude dependence under $U$ ≥ 5 m/s. The MII was defined as $MII={\theta }_{tilt}\times (1+k·{\displaystyle \frac{H_s}{H_{ref}}})$, with $k$ = 1.0 adopted as an engineering default, and four quality classes were established using the 50th, 80th, and 95th percentiles. Time-split testing, parameter-sensitivity analysis, and bootstrap resampling indicated that the thresholds were statistically stable. When stratified by ERA5 wind speed, the buoy–ERA5 bias increased systematically across the four classes, supporting their interpretation as progressively different measurement conditions. The numerical MII thresholds reported here are specific to the platform type and deployment site; when applied to other buoy designs or sea areas, the thresholds should be recalibrated from local data. Full article

Background: With accelerated population aging, depressive symptoms in later life have become a major public health issue. The Chinese version of the MIND (cMIND) diet is a neuroprotective dietary pattern adapted to Chinese dietary habits. Previous studies have found that adherence to the cMIND diet is associated with lower levels of depressive symptoms, but the underlying statistical association patterns remain unclear. This study adopted a statistical moderated mediation framework to characterize cross-sectional associations, to examine the direct association between cMIND diet adherence and depressive symptoms, the statistical associational mediating pattern of social participation, and the exploratory moderating effect of exercise on the first segment of the statistical mediation chain. Methods: Data were drawn from the 2018 wave of the Chinese Longitudinal Healthy Longevity Survey (CLHLS), including 8578 adults aged 65 years and older. Cross-sectional mediation and moderated mediation analyses were conducted using Model 4 and Model 7 of the PROCESS macro, with 5000 bootstrap resamples to test the significance of cross-sectional statistical indirect effects. Results: cMIND diet adherence was negatively associated with depressive symptoms (B = −0.414, p < 0.01). Social participation showed a statistical partial mediation pattern in this association, with the statistical indirect effect accounting for 14.02% of the total effect. Exploratory moderated mediation analysis showed that exercise moderated the first segment of the statistical mediation chain (B = 0.283, p < 0.01). The positive association between cMIND diet adherence and social participation was stronger among exercisers (simple slope = 0.635, p < 0.01) than among non-exercisers (simple slope = 0.352, p < 0.01). Correspondingly, the indirect association between cMIND diet adherence and depressive symptoms through social participation was stronger in the exercise group (indirect effect = −0.064, 95% CI [−0.079, −0.050]) than in the non-exercise group (indirect effect = −0.036, 95% CI [−0.045, −0.026]). Conclusions: Among Chinese older adults, higher adherence to the cMIND diet is significantly associated with lower levels of depressive symptoms, and this association shows a partial statistical mediation pattern linked to higher social participation. The positive association between cMIND diet adherence and social participation is more pronounced among adults who engage in regular exercise, which corresponds to a more pronounced statistical indirect association with depressive symptoms through social participation. As these findings are based on cross-sectional data and reflect only associational patterns, and given the limited effect magnitude, they provide only preliminary theoretical reference for the development of intervention strategies integrating dietary improvement and social participation promotion for late-life depressive symptoms. Full article