Objective:To provide support for efficient aeromedical support to aircrews by preliminarily investigating the current situation of asthenopia in civil aviation aircrews and analyzing its influencing factors.Methods:A cross-sectional study was used. Seventeen items of Asthenopia Survey Questionnaire (ASQ-17), that was developed by the asthenopia research team of Eye Hospital of Wenzhou Medical University, was conducted on aircrews of China Southern Airlines Co., Ltd. from September 23, 2022 to December 29, 2022. The situation and risk factors of asthenopia, as well as the symptoms mentioned in ASQ-17 were evaluated and analyzed in civil aviation aircrews. The risk factors of asthenopia were analyzed by multivariate Logistic regression analysis.Results:A total of 556 questionnaires were collected, and 516 were valid, with an effective recovery rate of 92.8%. The detection rate of asthenopia in civil aviation aircrews was 31.40%. There were significant differences in the detection rate of asthenopia between genders and the groups with and without ametropia and among the job types of aircrews ( χ2=10.07, 8.34, 11.83, P=0.002, 0.004, 0.003), but there was no significant difference in the detection rate of asthenopia between age groups (<40 years and ≥40 years) and whether corneal refractive surgery of aircrews (both P>0.05). There were significant differences in the detection rate of asthenopia among the aircrews with varying durations of close-up eye use, different sleep qualities and severities of anxiety even depression ( χ2=16.33, 36.34, 62.65, P=0.003,<0.001,<0.001), with an increasing trend in the detection rates of asthenopia corresponding to the prolonged durations of close-up eye use, the decreased sleep quality and the aggravated anxiety even depression. Multivariate Logistic regression analysis showed that job types, duration of close-up eye use, sleep quality, anxiety even depression and ametropia were the main risk factors for the occurrence of asthenopia ( OR=1.881-5.824, P=0.007-0.040). The results of ASQ-17 showed that the top 3 eyes symptoms of asthenopia in civil aviation aircrews were dry eyes, eyes soreness and periocular discomfort, with an average score of 18.06 on the ASQ-17. Conclusions:The detection rate of asthenopia in civil aviation aircrews is relatively high. The causes of asthenopia include dry eyes, excessive close-up eye use, ametropia and psychological factors according to the preliminary analysis. Aviation physicians should provide scientific and reasonable advice and intervention on the risk factors of asthenopia, with the aim of providing professional support for the visual health of aircrews.

Objectives:To investigate the morphological characteristics of the lower cervical vertebrae in Chinese Han multilevel cervical spondylotic myelopathy(MCSM)patients and to compare it with European Caucasian MCSM patients.Methods:The MCSM patients who underwent expansive single open-door lamino-plasty(EOLP)between December 2016 and May 2022 at the Affliated Drum Tower Hospital,Medical School of Nanjing University and Clinique Du Parc,France were divided into two groups based on ethnicity.Group A consisted of 80 Chinese Han MCSM patients(42 males and 38 females,mean age 62.3±10.5 years),while group B consisted of 29 European Caucasian MCSM patients(15 males and 14 females,mean age 58.4±12.6 years).The lamina inner width(LIW)at hinge place,lamina outer width(LOW)at hinge place,lamina axis length(LAL)and lamina transverse angle(LTA)of the patients were measured on CT plain scan images before operation.Independent sample t-test was performed to compare the differences in C3-C7 imaging parameters between the two groups.Results:LIW and LOW decreased from C3 to C5,and increased from C5 to C7 in both groups.Group A was significantly smaller in LAL at each level than group B(C3:12.1mm vs 13.4mm;C4:12.5mm vs 13.5mm;C5:12.8mm vs 13.9mm;C6:13.1mm vs 14.4mm;C7:13.5mm vs 14.4mm),while larger in LIW(C3:2.8mm vs 2.4mm;C4:2.4mm vs 1.9mm;C5:2.2mm vs 1.7mm;C6:2.7mm vs 2.3mm;C7:4.1mm vs 3.7mm)with significant differences in C3-C6(P＜0.05).No significant differences were found in LOW and LTA between the two groups at each level(P＞0.05)Conclusions:In Chinese Han and European Caucasian MCSM patients,C5 is the thinnest lamina among the lower cervical vertebrae with the highest risk during grooving in EOLP,and the risk is theoretically higher in Chinese Han MCSM patients than that in Caucasian MCSM patients.

Bone formation and deposition are initiated by sensory nerve infiltration in adaptive bone remodeling. Here, we focused on the role of Semaphorin 3A (Sema3A), expressed by sensory nerves, in mechanical loads-induced bone formation and nerve withdrawal using orthodontic tooth movement (OTM) model. Firstly, bone formation was activated after the 3rd day of OTM, coinciding with a decrease in sensory nerves and an increase in pain threshold. Sema3A, rather than nerve growth factor (NGF), highly expressed in both trigeminal ganglion and the axons of periodontal ligament following the 3rd day of OTM. Moreover, in vitro mechanical loads upregulated Sema3A in neurons instead of in human periodontal ligament cells (hPDLCs) within 24 hours. Furthermore, exogenous Sema3A restored the suppressed alveolar bone formation and the osteogenic differentiation of hPDLCs induced by mechanical overload. Mechanistically, Sema3A prevented overstretching of F-actin induced by mechanical overload through ROCK2 pathway, maintaining mitochondrial dynamics as mitochondrial fusion. Therefore, Sema3A exhibits dual therapeutic effects in mechanical loads-induced bone formation, both as a pain-sensitive analgesic and a positive regulator for bone formation.
Humans ; Bone Remodeling ; Cell Differentiation ; Osteogenesis ; Semaphorin-3A/pharmacology* ; Trigeminal Ganglion/metabolism*

Bone formation and deposition are initiated by sensory nerve infiltration in adaptive bone remodeling.Here,we focused on the role of Semaphorin 3A(Sema3A),expressed by sensory nerves,in mechanical loads-induced bone formation and nerve withdrawal using orthodontic tooth movement(OTM)model.Firstly,bone formation was activated after the 3rd day of OTM,coinciding with a decrease in sensory nerves and an increase in pain threshold.Sema3A,rather than nerve growth factor(NGF),highly expressed in both trigeminal ganglion and the axons of periodontal ligament following the 3rd day of OTM.Moreover,in vitro mechanical loads upregulated Sema3A in neurons instead of in human periodontal ligament cells(hPDLCs)within 24 hours.Furthermore,exogenous Sema3A restored the suppressed alveolar bone formation and the osteogenic differentiation of hPDLCs induced by mechanical overload.Mechanistically,Sema3A prevented overstretching of F-actin induced by mechanical overload through ROCK2 pathway,maintaining mitochondrial dynamics as mitochondrial fusion.Therefore,Sema3A exhibits dual therapeutic effects in mechanical loads-induced bone formation,both as a pain-sensitive analgesic and a positive regulator for bone formation.

Bone formation and deposition are initiated by sensory nerve infiltration in adaptive bone remodeling.Here,we focused on the role of Semaphorin 3A(Sema3A),expressed by sensory nerves,in mechanical loads-induced bone formation and nerve withdrawal using orthodontic tooth movement(OTM)model.Firstly,bone formation was activated after the 3rd day of OTM,coinciding with a decrease in sensory nerves and an increase in pain threshold.Sema3A,rather than nerve growth factor(NGF),highly expressed in both trigeminal ganglion and the axons of periodontal ligament following the 3rd day of OTM.Moreover,in vitro mechanical loads upregulated Sema3A in neurons instead of in human periodontal ligament cells(hPDLCs)within 24 hours.Furthermore,exogenous Sema3A restored the suppressed alveolar bone formation and the osteogenic differentiation of hPDLCs induced by mechanical overload.Mechanistically,Sema3A prevented overstretching of F-actin induced by mechanical overload through ROCK2 pathway,maintaining mitochondrial dynamics as mitochondrial fusion.Therefore,Sema3A exhibits dual therapeutic effects in mechanical loads-induced bone formation,both as a pain-sensitive analgesic and a positive regulator for bone formation.

Bone formation and deposition are initiated by sensory nerve infiltration in adaptive bone remodeling.Here,we focused on the role of Semaphorin 3A(Sema3A),expressed by sensory nerves,in mechanical loads-induced bone formation and nerve withdrawal using orthodontic tooth movement(OTM)model.Firstly,bone formation was activated after the 3rd day of OTM,coinciding with a decrease in sensory nerves and an increase in pain threshold.Sema3A,rather than nerve growth factor(NGF),highly expressed in both trigeminal ganglion and the axons of periodontal ligament following the 3rd day of OTM.Moreover,in vitro mechanical loads upregulated Sema3A in neurons instead of in human periodontal ligament cells(hPDLCs)within 24 hours.Furthermore,exogenous Sema3A restored the suppressed alveolar bone formation and the osteogenic differentiation of hPDLCs induced by mechanical overload.Mechanistically,Sema3A prevented overstretching of F-actin induced by mechanical overload through ROCK2 pathway,maintaining mitochondrial dynamics as mitochondrial fusion.Therefore,Sema3A exhibits dual therapeutic effects in mechanical loads-induced bone formation,both as a pain-sensitive analgesic and a positive regulator for bone formation.

Bone formation and deposition are initiated by sensory nerve infiltration in adaptive bone remodeling.Here,we focused on the role of Semaphorin 3A(Sema3A),expressed by sensory nerves,in mechanical loads-induced bone formation and nerve withdrawal using orthodontic tooth movement(OTM)model.Firstly,bone formation was activated after the 3rd day of OTM,coinciding with a decrease in sensory nerves and an increase in pain threshold.Sema3A,rather than nerve growth factor(NGF),highly expressed in both trigeminal ganglion and the axons of periodontal ligament following the 3rd day of OTM.Moreover,in vitro mechanical loads upregulated Sema3A in neurons instead of in human periodontal ligament cells(hPDLCs)within 24 hours.Furthermore,exogenous Sema3A restored the suppressed alveolar bone formation and the osteogenic differentiation of hPDLCs induced by mechanical overload.Mechanistically,Sema3A prevented overstretching of F-actin induced by mechanical overload through ROCK2 pathway,maintaining mitochondrial dynamics as mitochondrial fusion.Therefore,Sema3A exhibits dual therapeutic effects in mechanical loads-induced bone formation,both as a pain-sensitive analgesic and a positive regulator for bone formation.

Bone formation and deposition are initiated by sensory nerve infiltration in adaptive bone remodeling.Here,we focused on the role of Semaphorin 3A(Sema3A),expressed by sensory nerves,in mechanical loads-induced bone formation and nerve withdrawal using orthodontic tooth movement(OTM)model.Firstly,bone formation was activated after the 3rd day of OTM,coinciding with a decrease in sensory nerves and an increase in pain threshold.Sema3A,rather than nerve growth factor(NGF),highly expressed in both trigeminal ganglion and the axons of periodontal ligament following the 3rd day of OTM.Moreover,in vitro mechanical loads upregulated Sema3A in neurons instead of in human periodontal ligament cells(hPDLCs)within 24 hours.Furthermore,exogenous Sema3A restored the suppressed alveolar bone formation and the osteogenic differentiation of hPDLCs induced by mechanical overload.Mechanistically,Sema3A prevented overstretching of F-actin induced by mechanical overload through ROCK2 pathway,maintaining mitochondrial dynamics as mitochondrial fusion.Therefore,Sema3A exhibits dual therapeutic effects in mechanical loads-induced bone formation,both as a pain-sensitive analgesic and a positive regulator for bone formation.

Bone formation and deposition are initiated by sensory nerve infiltration in adaptive bone remodeling.Here,we focused on the role of Semaphorin 3A(Sema3A),expressed by sensory nerves,in mechanical loads-induced bone formation and nerve withdrawal using orthodontic tooth movement(OTM)model.Firstly,bone formation was activated after the 3rd day of OTM,coinciding with a decrease in sensory nerves and an increase in pain threshold.Sema3A,rather than nerve growth factor(NGF),highly expressed in both trigeminal ganglion and the axons of periodontal ligament following the 3rd day of OTM.Moreover,in vitro mechanical loads upregulated Sema3A in neurons instead of in human periodontal ligament cells(hPDLCs)within 24 hours.Furthermore,exogenous Sema3A restored the suppressed alveolar bone formation and the osteogenic differentiation of hPDLCs induced by mechanical overload.Mechanistically,Sema3A prevented overstretching of F-actin induced by mechanical overload through ROCK2 pathway,maintaining mitochondrial dynamics as mitochondrial fusion.Therefore,Sema3A exhibits dual therapeutic effects in mechanical loads-induced bone formation,both as a pain-sensitive analgesic and a positive regulator for bone formation.

Bone formation and deposition are initiated by sensory nerve infiltration in adaptive bone remodeling.Here,we focused on the role of Semaphorin 3A(Sema3A),expressed by sensory nerves,in mechanical loads-induced bone formation and nerve withdrawal using orthodontic tooth movement(OTM)model.Firstly,bone formation was activated after the 3rd day of OTM,coinciding with a decrease in sensory nerves and an increase in pain threshold.Sema3A,rather than nerve growth factor(NGF),highly expressed in both trigeminal ganglion and the axons of periodontal ligament following the 3rd day of OTM.Moreover,in vitro mechanical loads upregulated Sema3A in neurons instead of in human periodontal ligament cells(hPDLCs)within 24 hours.Furthermore,exogenous Sema3A restored the suppressed alveolar bone formation and the osteogenic differentiation of hPDLCs induced by mechanical overload.Mechanistically,Sema3A prevented overstretching of F-actin induced by mechanical overload through ROCK2 pathway,maintaining mitochondrial dynamics as mitochondrial fusion.Therefore,Sema3A exhibits dual therapeutic effects in mechanical loads-induced bone formation,both as a pain-sensitive analgesic and a positive regulator for bone formation.