Background When live working line operators engage in upper limb operations, working for a long time with raising arms and the exposure to adverse ergonomic factors tend to increase muscle load, cause fatigue accumulation, and increase the risk of work-related musculoskeletal disorders (WMSDs). Objective To analyze work posture and associated muscle fatigue during executing breaking/connecting contact terminal, and identify adverse ergonomic factors of the work process. Methods This study recruited 10 volunteers to perform breaking/connecting contact terminal simulation. At a distance of 4.5, 3.5, and 2.5 m from the body to the wire, each performed the task 5 times. Visual 3D was used to analyze the kinematic data from motion capture. The surface electromyography (sEMG) signals of the deltoid, biceps, triceps, and brachioradialis were recorded during the simulation and analyzed for muscle fatigue using root mean square (RMS), median frequency (MF), and jointed EMG amplitude and spectrum analysis (JASA). After completion of each task, Borg scale was used to query the volunteers of their subjective fatigue. A 2-min rest was required between each distance. Results The kinematic data from motion capture showed that in the entire process of the task, the right upper limb was higher when lifting, with the right shoulder joint maintaining flexion and fluctuating periodically between abduction and adduction, external and internal rotation, the right elbow joint maintaining flexion and supination. The frequency of task cycle showed a significant effect on the Borg scale scores (P<0.001, partial \begin{document}$ {\eta }^{2} $\end{document}=0.464); the distance showed no significant effect on the Borg scale scores (P>0.05, partial \begin{document}$ {\eta }^{2} $\end{document}=0.002); their interaction effect was not significant (P>0.05, partial \begin{document}$ {\eta }^{2} $\end{document}=0.020). The results of the sEMG signals showed that at a distance of 4.5 m, the volunteers had the highest percentages of maximal voluntary electrical activation (MVE%) in the deltoid and right brachioradialis and the lowest MF values in the deltoid and left brachioradialis after completing 5 task cycles. The results of JASA showed that fatigue was observed in brachioradialis and deltoid after completing 5 task cycles at a distance of 4.5 m, the right deltoid and right brachioradialis at a distance of 3.5 m, in the brachioradialis, deltoid, and left bicep at a distance of 2.5 m. Conclusion The subjective fatigue of workers who engaged in breaking/connecting contact terminal elevates with more repetitive operations. Based on the sEMG and motion capture analysis, it can be found that improper distance between the workers and the target work area can increase the burden from poor posture and improper use of work equipment, and lead to muscle fatigue; the deltoid and brachioradialis are the key muscles of fatigue in this type of operation; changing the angle of the elbow joint and the shoulder joint during the process of the operation can affect the deltoid and brachioradialis exertion and loading.

Background Power grid is an important component of the national infrastructure. The occupational health issues among the workers in this industry are attracting great concern nationwide. Objective To investigate the prevalence of work-related musculoskeletal disorders (WMSDs) in neck and shoulder among the power distribution workers of power supply enterprises, and analyze the related influencing factors. Method In April 2023, a total of 1244 workers in 50 municipal power supply bureaus were randomly selected from the three provinces under China Southern Power Grid using cluster sampling method. The questionnaire used in the study was based on a revised Musculoskeletal Disorders Questionnaire and added ergonomic load of upper limb work. \begin{document}$ {\chi }^{2} $\end{document} test and logistic regression model were used to explore the influencing factors of neck pain and shoulder pain among the subjects. Results A total of 1244 valid questionnaires were recovered and the effective recovery rate was 90.87%(1244/1369). The positive rates of neck pain and shoulder pain were 45.5% (566 cases) and 36.3% (452 cases) respectively. The logistic regression analysis results showed that more than 20 years working age (OR=2.27, 95%CI: 1.39, 3.96; OR=2.56, 95%CI: 1.53, 4.26), often (OR=2.08, 95%CI: 1.35, 3.20; OR=2.40, 95%CI: 1.50, 3.58)/quite often (OR=2.96, 95%CI: 1.73, 5.04; OR=2.72, 95%CI: 1.49, 4.94) maintaining a forced posture, and working immediately after break (OR=1.72, 95%CI: 1.04, 2.85; OR=2.14, 95%CI: 1.19, 3.88) were associated with a higher positive rate of neck pain and shoulder pain respectively. Feeling sufficient rest (OR=0.61, 95%CI: 0.47, 0.80; OR=0.63, 95%CI: 0.50, 0.83) and opportunity to decide when to take breaks (OR=0.72, 95%CI: 0.53, 0.98; OR=0.62, 95%CI: 0.41, 0.93) were associated with a lower positive rate of neck pain and shoulder pain respectively. Conclusion The positive rates of neck pain and shoulder pain are high among power distribution workers. The main influencing factors included long working age, quite often maintaining a forced posture, and working immediately after break.

Objective: To explore the prospective association between multidimensional sleep indicators and the risk of newlyonset dental caries, providing a reference for childrens oral healthrelated sleep intervention. Methods: In October 2021, 1 417 students in grades 1 to 4 (aged 6 to 11) from two elementary schools in Bengbu, Anhui Province, were selected by cluster sampling method. Surveys and followup visits were conducted at baseline (T1), November 2022 (T2), May 2023 (T3), and November 2023 (T4), respectively, including parental questionnaires, oral health and physical examination. Bedtime, sleep duration, sleep midpoint, social jet lag, weekend catchup sleep, and sleep habits were collected and calculated. A multifactorial Cox proportional risk regression model was used to analyze the association between multidimensional sleep indicators and newlyonset caries in schoolaged children after 2 years. Results: The prevalence of dental caries in children was 65.1% at baseline, and the prevalence was 59.0% at the end of the 2year followup. Cox proportional risk regression model showed that for every 1point increase in the childrens bedtime resistance, nocturnal awakenings, parasomnias, and daytime sleepiness scores, the risk of newlyonset caries increased by 12% (HR=1.12, 95%CI=1.08-1.15), 22% (HR=1.22, 95%CI=1.15-1.29), 12% (HR=1.12, 95%CI=1.08-1.17), and 15% (HR=1.15, 95%CI=1.12-1.19), respectively; the risk of newlyonset caries increased by 23% for each 1 h increase in the length of weekend catchup sleep (HR=1.23, 95%CI=1.14 -1.33); compared with children who went to bed before 21:00 on school days, those who went to bed later than 22:00 had a 57% higher risk of newlyonset caries (HR=1.57, 95%CI=1.22-2.03). Compared to children who slept adequately (≥9 h/d), those with insufficient sleep had a 67% higher risk of new caries (HR=1.67, 95%CI=1.43-1.95) (P<0.01). Conclusions These findings suggest a significant association between sleep patterns/sleep disorders and the development of childhood dental caries. Incorporating sleep behavior optimization and sleep quality improvement into comprehensive caries prevention and oral health management protocols may represent a promising intervention strategy to enhance childrens oral health outcomes.

Urticarial vasculitis is a skin disease with urticaria-like lesions and a histopathological pattern of leukocytoclastic vasculitis. It is considered a "hidden rash" in traditional Chinese medicine. Xuanfu is the portal that regulates qi, blood, fluid, and the ascending, descending, exiting, and entering of nutrition qi and defensive qi. Collaterals are the pathways for the circulation of qi and blood. The two accompany each other, connecting zang-fu organs, reaching the surfaces of the skin, hair, and external body, circulating qi and fluid, and moistening and protecting the skin. Based on the theory of Xuanfu-collateral, this study aimed to clarify the etiology, pathogenesis, and treatment method of urticarial vasculitis. External assault by wind and Xuanfu blockage are believed to be the initiating factors of this disease. The malnutrition of Xuanfu and collaterals and accumulated dampness-heat are important links in the occurrence and development of urticarial vasculitis. It spreads from Xuanfu to the collaterals, and blockage of the collaterals is the immanent trend of this disease. Clinically, by closely adhering to the core pathogenesis of blockage of Xuanfu-collateral, treatment method such as using wind medicinals to open Xuanfu with pungent and dispersing properties, using the method of supplement deficiency and removing the blockage, and using medicinals to promote blood circulation and remove blood stasis to unblock the blocked collaterals. The herbs are flexibly added or subtracted to unblock Xuanfu and collaterals, harmonize qi and blood, thus all symptoms can be relieved. We hope that this study will provide new ideas for the treatment of urticarial vasculitis with traditional Chinese medicine.

Alzheimer’s disease (AD) is a neurodegenerative disorder characterized by progressive cognitive decline, functional impairment, and neuropsychiatric symptoms. It represents the most prevalent form of dementia among the elderly population. Accumulating evidence indicates that oxidative stress plays a pivotal role in the pathogenesis of AD. Notably, elevated levels of oxidative stress have been observed in the brains of AD patients, where excessive reactive oxygen species (ROS) can cause extensive damage to lipids, proteins, and DNA, ultimately compromising neuronal structure and function. Amyloid β‑protein (Aβ) has been shown to induce mitochondrial dysfunction and calcium overload, thereby promoting the generation of ROS. This, in turn, exacerbates Aβ aggregation and enhances tau phosphorylation, leading to the formation of two pathological features of AD: extracellular Aβ plaque deposition and intracellular neurofibrillary tangles (NFTs). These events ultimately culminate in neuronal death, forming a vicious cycle. The interplay between oxidative stress and these pathological processes constitutes a core link in the pathogenesis of AD. The signaling pathways mediating oxidative stress in AD include Nrf2, RCAN1, PP2A, CREB, Notch1, NF‑κB, ApoE, and ferroptosis. Nrf2 signaling pathway serves as a key regulator of cellular redox homeostasis, exerts important antioxidant capacity and protective effects in AD. RCAN1 signaling pathway, as a calcineurin inhibitor, and modulates AD progression through multiple mechanisms. PP2A signaling pathway is involved in regulating tau phosphorylation and neuroinflammation processes. CREB signaling pathway contributes to neuroplasticity and memory formation; activation of CREB improves cognitive function and reduce oxidative stress. Notch1 signaling pathway regulates neuronal development and memory, participates in modulation of Aβ production, and interacts with Nrf2 toco-regulate antioxidant activity. NF‑κB signaling pathway governs immune and inflammatory responses; sustained activation of this pathway forms “inflammatory memory”, thereby exacerbating AD pathology. ApoE signaling pathway is associated with lipid metabolism; among its isoforms, ApoE-ε4 significantly increases the risk of AD, leading to elevated oxidative stress, abnormal lipid metabolism, and neuroinflammation. The ferroptosis signaling pathway is driven by iron-dependent lipid peroxidation, and the subsequent release of lipid peroxidation products and ROS exacerbate oxidative stress and neuronal damage. These interconnected pathways form a complex regulatory network that regulates the progression of AD through oxidative stress and related pathological cascades. In terms of therapeutic strategies targeting oxidative stress, among the drugs currently used in clinical practice for AD treatment, memantine and donepezil demonstrate significant therapeutic efficacy and can improve the level of oxidative stress in AD patients. Some compounds with antioxidant effects (such asα-lipoic acid and melatonin) have shown certain potential in AD treatment research and can be used as dietary supplements to ameliorate AD symptoms. In addition, non-drug interventions such as calorie restriction and exercise have been proven to exerted neuroprotective effects and have a positive effect on the treatment of AD. By comprehensively utilizing the therapeutic characteristics of different signaling pathways, it is expected that more comprehensive multi-target combination therapy regimens and combined nanomolecular delivery systems will be developed in the future to bypass the blood-brain barrier, providing more effective therapeutic strategies for AD.

Objective: To investigate the influencing factors for cognitive function among aluminum workers, so as to provide the basis for intervention and prevention of cognitive function among aluminum-exposed populations. Methods: From July to August 2019, male aluminum workers in the electrolytic aluminum workshop of an aluminum factory in Shanxi Province were selected using the cluster sampling method. Demographic information, prevalence of chronic diseases, lifestyle behaviors, night shifts, and sleep quality were collected through questionnaire surveys. Blood aluminum levels were measured using inductively coupled plasma-mass spectrometry. Cognitive function was investigated using the Montreal Cognitive Assessment. Factors affecting cognitive function among aluminum workers were analyzed by a quantile regression model. Results: A total of 142 aluminum workers were surveyed, including 57 workers aged 20 to <40 years (40.14%) and 85 workers aged 40 to 60 years (59.86%). The median blood aluminum level was 38.23 (interquartile range, 21.82) μg/L. The median cognitive function score was 24.00 (interquartile range, 3.00) points. Quantile regression analysis revealed that older age (βQ5=-0.186, 95%CI: -0.269 to -0.102), lower educational level (βQ5=1.933, 95%CI: 1.029 to 2.838; βQ10=1.743, 95%CI: 0.480 to 3.006; βQ50=1.038, 95%CI: 0.141 to 1.935; βQ75=1.006, 95%CI: 0.437 to 1.575; βQ90=1.111, 95%CI: 0.291 to 1.930), smoking (βQ5=-2.056, 95%CI: -3.264 to -0.849), alcohol consumption (βQ5=-1.821, 95%CI: -3.247 to -0.396) and higher blood aluminum level (βQ5=-0.075, 95%CI: -0.110 to -0.040; βQ10=-0.078, 95%CI: -0.127 to -0.029; βQ50=-0.075, 95%CI: -0.110 to -0.040; βQ75=-0.057, 95%CI: -0.079 to -0.035; βQ90=-0.067, 95%CI: -0.099 to -0.035) were associated with cognitive function decline among aluminum workers. Conclusions Educational level and blood aluminum level are the main factors affecting the cognitive function among aluminum workers. Among those with lower cognitive function scores, age, smoking and alcohol consumption are also associated with cognitive function.

Under the trend of increasing aging， integrated elderly care and medical services is an important measure to optimize the supply of elderly care services and promote the good death of the elderly. Using the cooperative production theory and the classical grounded theory， a qualitative analysis was conducted on 38 cases of elderly palliative care and 25 cases of hospital-based palliative care under the integrated elderly care and medical services model from a hospital in Nanning City using Nvivo 20.0 software. This paper found that the integrated elderly care and medical services mode emphasized the deep integration of medical and elderly care services by integrating resources and improving service efficiency， to achieve the basic experience of comprehensive health care for the elderly. The promotion of these experiences has a positive significance for building a multi-agent cooperative production system， strengthening personnel training， perfecting the performance distribution mechanism， and further promoting the development of the national palliative care pilot.

Objective: To understand classroom environmental conditions and their association with spinal curvature abnormalities among students of primary and secondary schools in Guizhou Province, so as to provide a basis for formulating school health policies and scientific prevention and control measures for abnormal spinal curvature in students. Methods: Using a stratified random sampling method, 471 schools (2 811 classrooms) were selected annually across the province from 2022 to 2024 in order to monitor and evaluate classroom environment according to national standards. Spinal examinations were conducted for 196 606 (2022), 194 876 (2023), and 195 048 (2024) students, and χ 2 test was used to analyze the correlation of desk and chair compliance with student spinal curvature abnormalities. Results: The qualified rates of classroom blackboard illuminance uniformity ( 85.41 %) and the blackboard size (82.24%) were the highest in primary and secondary schools in Guizhou Province, while the average blackboard surface illumination qualified rate (20.10%) was the lowest. The average desk illumination (50.11%-58.63%), desk illumination uniformity (61.92%-72.27%) and qualified noise rate (50.04%-51.94%) increased significantly in 3 years; in addition, the compliance rate of desks and chairs decreased from 25.00% to 13.52%, and the differences were all statistically significant ( χ 2=42.48, 80.93, 46.09, 129.72, all P <0.05). Middle school classrooms outperformed primary schools in terms of per capita area, average blackboard illuminance, blackboard illuminance uniformity, average desktop illuminance, desktop illuminance uniformity, and noise compliance ( χ 2=311.55, 12.41, 20.64, 40.76, 10.25, 52.47), but had lower compliance for blackboard size and reflectance ( χ 2=537.29, 7.59) (all P <0.01). Urban schools had higher compliance than suburban schools for per capita area, average blackboard illuminance, average desktop illuminance, and desktop illuminance uniformity ( χ 2=73.71, 17.68, 29.30 , 36.03), but lower compliance for desk-chair suitability, blackboard size, and blackboard reflectance ( χ 2=4.72, 26.02, 5.43 ) (all P <0.05). The spinal curvature abnormality detection rate was 0.83%. A significant association was found between abnormality detection and desk-chair non compliance ( χ 2=223.85, P <0.01). Conclusions Classroom environment hygiene in Guizhou schools is suboptimal. Strengthening school environmental hygiene infrastructure and greater attention to its impact on student s health are essential.

Objective: To understand the epidemiological characteristics of abnormalities spinal curvature among children and adolescents in Karst landform in Guizhou Province, so as to provide a scientific basis for targeted comprehensive intervention. Methods: From September to December 2023, 194 875 children and adolescents aged 6-18 were selected from all countieldistricts of 9 cities (prefectures) in Guizhou Province by stratified random cluster sampling method according to the proportion of Karst landform area in Guizhou Province for carrying out spinal curvature abnormality screening, and a questionnaire survey was conducted on 139 449 students in the fourth grade and above of primary school. Binary Logistic regression was used for multivariate analysis. Results: The detection rate of abnormal spinal curvature among children and adolescents aged 6-18 in Guizhou Province was 1.13%. The detection rates of abnormal spinal curvature in areas with a high proportion of Karst landform, areas with a low proportion of Karst landform, intercalation areas, and nonKarst landform areas were 1.10%, 2.00%, 0.90%, and 0.60%, respectively. Among them, the detection rates of abnormal spinal curvature in female students (2.40%, 1.60%, 0.90%) in areas with a low proportion of Karst landform, intercalation areas and nonKarst landform were higher than those in male students (1.60%, 0.10%, 0.30) (χ2=12.66, 112.69, 30.22, all P<0.05). The detection rates of abnormal spinal curvature among senior high school students (2.00%, 4.30%, 1.40%, 1.30%) in different Karst landform distributions were successively higher than those among junior high school students (1.40%, 3.20%, 1.00%, 0.60%) and primary school students (0.70%, 0.80%, 0.60%, 0.30%) (χ2=306.11, 175.80, 14.24, 39.57, all P<0.05). The results of multivariate Logistic regression analysis showed that the detection rates of abnormal spinal curvature in both highproportion and lowproportion Karst landform areas were higher than those in nonKarst landform areas [OR(95%CI)=1.84(1.05-2.25), 1.60(1.23-2.09), both P<0.05]. Conclusion The detection rate of abnormal spinal curvature in children and adolescents aged 6-18 in Guizhou Province is related to the distribution of Karst landform, so it is necessary to strengthen screening and appropriate comprehensive interventions.

ObjectiveTo systematically investigate the identification characteristics of medicinal amber， elucidate its microscopic features， crystal structural properties， and elemental composition， and thereby provide a scientific foundation for quality control and authenticity verification. MethodsThirty-nine batches of amber samples were collected and analyzed through integrated techniques including morphological analysis， microscopic identification， powder X-ray diffraction （XRD）， Raman spectroscopy， Fourier-transform infrared （FTIR） spectroscopy， and inductively coupled plasma mass spectrometry （ICP-MS） to evaluate their morphological attributes， phase composition， molecular vibrational modes， and trace element profiles. Among them， the XRD experiment used Cu Kα radiation （λ=1.540 6 Å）， with a scanning angle range of 10° to 70° （2θ） and a step size of 0.02°， the Raman spectroscopy experiment employed a 785 nm laser， with a spectral measurement range of 3 400 to 50 cm^-1， a laser power of 300 mW， a laser intensity of 30%， and a scanning time of 100 to 1 000 ms， the infrared spectroscopy experiment used a carbon-sulfur lamp， with a scanning range of 4 000 to 500 cm^-1， a resolution of 4 cm^-1， and 3 scans， the ICP-MS experiment utilized frequency power of 1.2 kW， a double-pass cyclonic spray chamber， a sample introduction system flow rate of 0.7-1.0 L·min^-1， and an auxiliary gas flow of 0.2 L·min^-1. ResultsUnder orthogonal polarized light microscopy， medicinal amber exhibited an isotropic homogeneous structure， with partial samples containing inorganic impurities such as AsS and SiO₂. FTIR spectra revealed characteristic absorption peaks at 2 932-2 939 cm^-1 （C-H stretching vibrations）， 1 705-1 728 cm^-1 （C=O stretching vibrations）， and 880-887 cm^-1 （C=C deformation vibrations）， confirming the oxidative polymerization of terpenoid resin. Raman spectroscopy further identified distinctive peaks at 2 925 cm^-1， 2 870 cm^-1 （saturated C-H stretching）， and 1 648 cm^-1 （C=C stretching）， consistent with the structural features of oxidized-polymerized resin. ICP-MS analysis demonstrated that S， Al， Si， Fe， Na， and Ca were the predominant trace elements in medicinal amber. ConclusionThis study comprehensively evaluated medicinal amber's morphological attributes， phase composition， molecular vibrational modes， and trace elements through multimodal analytical techniques. The findings establish data support for establishing quality standards for medicinal amber and distinguishing it from synthetic resin imitations.