Objective To evaluate the role of distortion product otoacoustic emissions (DPOAE) testing in evaluating early hearing loss among noise-exposed workers. Methods A total of 174 noise-exposed workers in a metal shipbuilding enterprise were selected as the research subjects by the convenience sampling method. Pure tone audiometry (PTA), DPOAE and the level of noise exposure were conducted on the workers. The rank correlation analysis was used to analyze the correlation between DPOAE amplitude and PTA threshold. The multilevel model was used to analyze the effects of gender, age, noise exposure intensity, cumulative noise exposure (CNE), hearing loss classification and PTA threshold on DPOAE results. Results At the frequencies of 0.50, 1.00, 2.00, 3.00, 4.00, 6.00 and 8.00 kHz, the DPOAE amplitude was negatively correlated with the PTA threshold (rank correlation coefficients were -0.12, -0.48, -0.47, -0.18, -0.23, -0.44, -0.19, respectively, all P<0.01). At the most frequencies, DPOAE amplitude was negatively correlated with age and CNE (all P<0.05). The results of multilevel model analysis showed that there were significant differences in DPOAE amplitudes at certain frequencies across gender, age, noise intensity, CNE, and hearing loss classification (all P<0.05). Significant differences in DPOAE responses were found among different CNE and hearing loss groups (all P<0.01). Conclusion DPOAE testing can objectively reflect the hearing status of noise-exposed workers and could be considered for inclusion in routine hearing monitoring to facilitate early detection of noise-induced hearing loss.

Objective: To investigate the distribution of pupil diameter and its association with myopia in school age children, providing ideas into the mechanisms of the role of pupil diameter in the onset and development of myopia. Methods: Adopting a combination of stratified cluster random sampling and convenience sampling method, 3 839 children from six schools in Shandong Province were included in September 2021. Pupil diameters distribution was analyzed by age, sex, and myopic status. Pearson correlation analysis was used to assess the relationship between pupil diameter and cycloplegic spherical equivalent (SE), as well as axial length (AL) and other variables. Propensity score matching (PSM) was applied to match myopic and non myopic children at a 1∶1 ratio based on age and sex. A generalized linear model (GLM) was constructed with pupil diameter as the dependent variable to identify independent factors influencing pupil size and its association with myopia. Results: The mean pupil diameter of school age children was (5.77±0.80)mm. Pupil diameter exhibited a significant increasing trend with age ( F =49.34， P trend ＜ 0.01). Myopic children had a significantly larger mean pupil diameter [(6.10±0.73)mm] compared to non myopic children [(5.62±0.79)mm] with a statistically significant difference( t=18.10, P <0.01). Multivariable GLM analysis, adjusted for age, amplitude of accommodation, and uncorrected visual acuity, revealed a negative correlation between pupil diameter and cycloplegic SE (before PSM: β =-0.089, after PSM: β =-0.063, both P ＜0.01). Conclusions Myopic school age children exhibite larger pupil diameters than their non myopic counterparts. Pupil diameter may serve as a potential indicator for monitoring myopia development in school age children.

ObjectiveTo analyze the spectrum distribution characteristics of high-intensity productive noise in key industries in Guangdong Province. Methods A total of 2 806 enterprises in 21 prefecture-level cities in Guangdong Province were selected as the study subjects using the stratified sampling method. On-site investigations were conducted in workplaces. Noise in workplaces and work-sites, and the noise spectrum of the workplaces with sound pressure level ≥85.0 dB(A) were detected. Results The noise of a total of 23 076 workplaces and 20 969 work sites from 30 key industries were monitored. The median (M) and 25th and 75th percentiles (P₂₅, P₇₅) of workplace sound pressure level were 82.3 (78.6, 86.5) dB(A). The rate of the noise exceeded national standard was 30.4%. The sound pressure level M (P₂₅, P₇₅) of work-site was 78.6 (70.0, 83.5) dB(A). The rate of the noise exceeded national standard was 18.0%. Workplace noise and work site noise were positively correlated (Spearman correlation coefficient=0.86, P<0.01). The rate of the noise exceeded national standard was 46.5% in key work sites where the rate of noise exceeded the national standard was ≥25.0%, and corresponding rate of the workplace noise exceeded national standard was 58.1%. The noise spectrum result of 5 636 workplaces sound pressure level>85.0 dB(A) showed that most of the noise source was from grinding machines (441 cases), and the highest average sound pressure level of noise source was from screening machines [93.0 dB(A)]. Cluster analysis results showed that the main noise sources could be divided into three categories, including wideband noise with levels >80.0 dB in all frequency bands except 8 000.0 Hz, medium-high-frequency noise with the highest sound pressure level at 1 000.0, 2 000.0, and 4 000.0 Hz and low frequencies <75.0 dB, and medium-low-frequency noise below 500.0 Hz with sound pressure level >85.0 dB. Conclusion The rate of the noise exceeded national standard in workplace of key industries in Guangdong Province is high, involving a wide range of industries, with high sound pressure levels and obvious spectrum characteristics of corresponding noise sources. Corresponding noise control strategies can be formulated based on different spectrum characteristics and magnitudes.

Objective:To investigate the common viral pathogen spectrum of acute respiratory infection (ARI) cases in Changshu city.Methods:Nasopharyngeal swab samples from outpatients and inpatients in five sentinel hospitals in Changshu city from January 2022 to October 2023 were collected. Real-time fluorescent quantitative polymerase chain reaction was used to detect the nucleic acids of influenza virus (Flu) and respiratory syncytial virus (RSV), adenovirus (AdV), human rhinovirus (HRV), human parainfluenza virus (HPIV), enterovirus (EV), human coronavirus (HCoV), human metapneumovirus (HMPV), and human bocavirus (HBoV).Results:Of the 1 936 ARI cases, 18.1% (350/1 936) were tested positive for viral nucleic acid. Flu had the highest detection rate (7.1%), followed by HBoV (3.7%), AdV (1.9%) and RSV (1.6%). The virus detection rate was significantly different among different age groups and seasons. In March 2023, the total virus detection rate was the highest (47.6%), mainly Flu. Flu showed unimodal prevalence in spring and winter. The prevalence trend of HBoV and HCoV was consistent, and the detection rate of HBoV (5.43%) was higher than that of HCoV (2.45%), both of which peaked in summer. RSV prevalence peaks in autumn (4.5%). The detection rate of children aged 0-5 years was the highest, reaching 33.3%.Conclusions:The main ARI pathogens in Changshu city from 2022 to 2023 were Flu, HBoV, AdV and RSV.

The incidence of osteoporotic thoracolumbar vertebral fracture (OTLVF) in the elderly is gradually increasing. The kyphotic deformity caused by various factors has become an important characteristic of OTLVF and has received increasing attention. Its clinical manifestations include pain, delayed nerve damage, sagittal imbalance, etc. Currently, the definition and diagnosis of OTLVF with kyphotic deformity in the elderly are still unclear. Although there are many treatment options, they are controversial. Existing guidelines or consensuses pay little attention to this type of fracture with kyphotic deformity. To this end, the Lumbar Education Working Group of the Spine Branch of the Chinese Medicine Education Association and Editorial Committee of Chinese Journal of Trauma organized the experts in the relevant fields to jointly develop Clinical guidelines for the diagnosis and treatment of osteoporotic thoracolumbar vertebral fractures with kyphotic deformity in the elderly ( version 2024), based on evidence-based medical advancements and the principles of scientificity, practicality, and advanced nature, which provided 18 recommendations to standardize the clinical diagnosis and treatment.

Objective: To analyze the status of noise hazard in workplace of key industries in Guangdong Province. Methods: A total of 1 061 enterprises from 14 key industries in 21 prefecture-level cities in Guangdong Province were selected as the research subjects using stratified sampling method. The occupational health survey was carried out, and the noise intensity in the workplace was detected. Results: There were 12 606 workplaces and 5 570 work sites involved among 1 061 enterprises. The median and the 0-100th percentile value ［M (P₀-P₁₀₀)］ of noise intensity in workplace were 82.6 (46.5-112.6) dB(A), and 35.03% of the workplace exceeded the national noise intensity standard. The regions and industry with the highest rate of noise exceeded the national noise intensity standard in workplace were in the northern part of Guangdong and the stone processing industry respectively. The M (P₀-P₁₀₀) of noise intensity in the work sites was 83.7 (47.5-106.2) dB(A), and 36.00% of the work sites exceeded the national noise intensity standard. The regions and industry with the highest rate of noise exceeded the national noise intensity standard in work sites were in the Pearl River Delta region and the ferrous metal mining and dressing industry respectively. The rate of noise protection facilities setting was 66.45%, and the validity of personal protection was 61.73%. The occupational medical examination was performed in 73.24% of the research subjects, and 3.25% of the result was abnormal. The industry with the highest occupational medical examination rate was nonferrous metal smelting and rolling processing, and the industry with the highest abnormal rate of occupational medical examination was stone processing industry. Conclusion: Noise hazards in workplaces of key industries in Guangdong Province are relatively severe, necessitating strengthened supervision and management, noise control measures, and efforts to reduce noise exposure levels in workplaces and work sites.

{L-End}Objective To analyze the characteristics of hearing loss and the influencing factors of high-frequency hearing loss (HFHL) among noise-exposed workers in an urban rail transit enterprise over five consecutive years. {L-End}Methods A total of 1 268 noise-exposed workers, who exposed to the average noise intensity of <85.0 dB(A), in an urban rail transit enterprise was selected as the research subjects using a judgment sampling method. The pure-tone audiometry results from 2019 to 2023 were collected to analyze the result of hearing loss. The influencing factors of HFHL (average hearing threshold ≥40.0 dB at high frequencies in both ears) were analyzed using the generalized estimating equations (GEE). {L-End}Results The detection rates of threshold elevations at frequencies of 0.5-6.0 kHz increased with increasing frequency from 2019 to 2023 (all P<0.01), with the highest detection rate at 6.0 kHz. The detection rate of speech frequency hearing loss (hearing threshold weighted value≥26.0 dB in the better ear) was 0.1%, 0.0%, 0.4%, 0.2%, and 0.2%, respectively. The detection rate of HFHL from 2019 to 2023 was 2.4%, 2.8%, 2.8%, 2.1%, and 2.8%, respectively. The GEE analysis results showed that the risk of HFHL of the workers in 2022 and 2023 was lower than that in 2019 (all P<0.01), with the odds ratios and 95% confidence intervals ［OR (95%CI)］ of 0.57 (0.41-0.81) and 0.65 (0.48-0.87), respectively. The risk of HFHL was higher among vehicle maintenance worker than train drivers (P<0.05), with OR (95%CI) of 2.37 (1.18-4.77). The risk of HFHL increased with age and length of service among the workers (all P<0.05), with the OR (95%CI) of 2.05 (1.22-3.46) and 1.69 (1.12-2.54), respectively. No interaction was found between type of job and age, type of job and length of service, or age and length of service in the risk of HFHL among the research subjects(all P<0.05). {L-End}Conclusion Noise exposure below the national occupational exposure limits can lead to hearing loss in noise-exposed workers of urban rail transit enterprises, possibly affecting the hearing threshold at 6.0 kHz first. The influencing factors for HFHL in workers of rail transit are age, length of service, and type of job. There is a dose-effect relationship with age and length of service.

Bone defects caused by different causes such as trauma, severe bone infection and other factors are common in clinic and difficult to treat. Usually, bone substitutes are required for repair. Current bone grafting materials used clinically include autologous bones, allogeneic bones, xenografts, and synthetic materials, etc. Other than autologous bones, the major hurdles of rest bone grafts have various degrees of poor biological activity and lack of active ingredients to provide osteogenic impetus. Bone marrow contains various components such as stem cells and bioactive factors, which are contributive to osteogenesis. In response, the technique of bone marrow enrichment, based on the efficient utilization of components within bone marrow, has been risen, aiming to extract osteogenic cells and factors from bone marrow of patients and incorporate them into 3D scaffolds for fabricating bone grafts with high osteoinductivity. However, the scientific guidance and application specification are lacked with regard to the clinical scope, approach, safety and effectiveness. In this context, under the organization of Chinese Orthopedic Association, the Expert consensus for the clinical application of autologous bone marrow enrichment technique for bone repair ( version 2023) is formulated based on the evidence-based medicine. The consensus covers the topics of the characteristics, range of application, safety and application notes of the technique of autologous bone marrow enrichment and proposes corresponding recommendations, hoping to provide better guidance for clinical practice of the technique.

BACKGROUND: Legg-Calvé-Perthes disease (LCPD) is still a refractory disease in children’s orthopedics. With the introduction of the concept of ‘‘osteoimmunology’’, the immune-inflammatory mechanisms between bone and immune system have become a research focus of LCPD. However, few studies have reported on the pathological role of inflammation-related receptors such as toll-like receptors (TLRs) as well as immune cells such as macrophages in LCPD. This study was for investigating the mechanism of TLR4 signaling pathway on the direction of macrophage polarization and the repair of avascular necrosis of femoral epiphysis in LCPD. METHODS: With GSE57614 and GSE74089, differentially expressed genes were screened. Through enrichment analysis and protein–protein interaction network, the functions of TLR4 were explored. Furthermore, immunohistochemistry, enzyme-linked immunosorbent assay (ELISA), hematoxylin & eosin (H&E) staining, micro-CT, tartrate-resistant acid phosphatase (TRAP) dyeing and western blotting were performed for determining the influences of TAK-242 (a TLR4 inhibitor) on the repair of avascular necrosis of femoral epiphysis in rat models. RESULTS: Totally 40 co-expression genes were screened as well as enriched in TLR4 signaling pathway. Immunohistochemistry and ELISA analyses certified that TLR4 facilitated macrophage polarization toward the M1 phenotype and prevented macrophage polarization toward the M2 phenotype. Besides, the results of H&E and TRAP staining, micro-CT, and western blotting showed that TAK-242 can inhibit osteoclastogenesis and promote osteogenesis. CONCLUSION Inhibition of TLR4 signaling pathway accelerated the repair of avascular necrosis of femoral epiphysis by regulating macrophage polarization in LCPD.

Background The converter stations of high-voltage direct current (HVDC) transmission lines generate special total electric fields. At present, few investigations have been conducted on total electric fields in the workplace of converter stations from an perspective of occupational health. Objective To understand the current situation of total electric field strength in the workplace of converter stations. Methods Using purposive sampling, a calibrated HDEM-1 direct current (DC) total electric field strength measurement system was used to measure the total electric fields of 12 converter stations serving 6 DC lines in Southeast and Southwest China according to the Measurement method for total electric field strength and ion current density of the converter stations and DC transmission lines (DL/T 1089—2008). The results were evaluated according to occupational exposure limits recommended by The limits of electromagnetic environment at ±800 kV UHV DC converter station (DL/T 275—2012), the American Conference of Governmental Industrial Hygienists (ACGIH), and the International Commission on Non-Ionizing Radiation Protection (ICNIRP). Results A total of 615 check points were planned, the total electric field strength was 0.05-37.05 kV·m⁻¹, and the median was 10.45 kV·m⁻¹. The total electric field strength of 39 check points (6.3%) exceeded 25 kV·m⁻¹ (the limits of ACGIH and ICNIRP), and the total electric field strength of 12 check points (2.0%) exceeded 30 kV·m⁻¹ (the limit of DL/T 275—2012). There were statistically significant differences in the total electric field strength values and the proportions of exceeding 25 kV·m⁻¹ between the neutral regions and the positive regions and between the neutral regions and the negative regions (P < 0.01). The proportion of total electric field strength exceeding 30 kV·m⁻¹ in the negative regions was higher than that in the positive regions (P < 0.01). There were no significant differences in the total electric field strength of converter stations at different voltage levels and different altitudes (P > 0.05). There were no significant differences in the proportions of total electric field exceeding 25 kV·m⁻¹ and exceeding 30 kV·m⁻¹ in converter stations at different voltage levels and different altitudes (P > 0.05). Conclusion The total electric field in some workplace of converter stations exceeds selected limits. Converter station operators may be exposed to high-strength total electric field for a short time.