Objective To explore the impact of pilots' visual attention features on combat performance during simulated air-to-air combat, and provide data for simulated air-to-air combat training. Methods A total of 25 pilots were selected as the subjects to complete simulated air to air combat tasks on a computer wearing an eye tracking device that recorded the pilots' eye movement while the computer recorded related combat performance indicators such as the time taken to complete a task and results of attacks. Eye movement indicators related to visual attention were selected before correlations with the time taken to complete a task were analyzed and a correlation regression model was constructed to study the differences in eye movement indicators between pilots with successful attacks and those whose attacks failed. Results There was a significant positive correlation between eleven eye tracking indicators and the time taken to lock in the enemy's aircraft（r=0.399-0.657, all P<0.05）.A linear regression equation was constructed that involved such eye movement indicators as the number of fixations on the radar image area, the entry time of the first complete fixation in the data area of the enemy's aircraft, the latency time of first complete fixation on the area of height data, and the average time taken by complete fixation on the task command area（R2=0.712, F=12.375, P<0.001）. There were four eye movement indicators that were significantly negatively correlated with attack duration（r=－0.459, －0.486, －0.480, －0.420, all P<0.05）. A linear regression equation between eye movement indicators and the time taken by an attack was constructed involving six eye movement indicators, including the total time of gaze at the radar image area, the number of gazes at the radar image area, the number of scans in the radar image area, the number of scans in the locked image area, the entry speed of peak scans in the airspeed data area, and the entry speed of peak scans in the data area of the enemy's aircraft（R2=0.736, F=3.540, P=0.017）. Compared with pilots who failed in an attack, the successful pilots had shorter latency times in the first fixation on the area of height data, the first complete fixation on the area of height data, the first complete fixation on the area of data on enemy's aircraft, and the first departure from the area of data on enemy's aircraft, and the differences were statistically significant（t=－2.206~－2.059, all P<0.05）. Conclusion In simulated air combat scenarios, pilots exhibit distinct visual attention patterns, and their eye tracking indicators can provide important data for simulated air-to-air combat training.
Objective To investigate the sleep quality and perceived stress of military aircrews and the moderating effects of coping styles. Methods The Pittsburgh Sleep Quality Index（PSQI）scale, the Perceived Stress Scale（PSS）, and the Simplified Coping Style Questionnaire（SCSQ）were employed to conduct a questionnaire survey among 102 military aircrews. The results of the survey were subjected to descriptive statistical analysis, correlation analysis, and moderation effect analysis on 98 valid questionnaires. Results The total score of PSQI for military aircrews was（7.95±3.03）points, and 39.80% of these aircrews（39/98）had sleep disorders（PSQI≥8 points）. The total score of PSS was（25.85±8.15）points, with 34.69%（34/98）experiencing high levels of stress and 6.12%（6/98）experiencing extremely high levels of stress. The sleep quality index was positively correlated with perceived stress and negative coping（r/rs=0.909, 0.901, all P<0.001）, while positive coping was negatively correlated with the sleep quality index, perceived stress, and negative coping（r/rs=－0.865, －0.911, －0.898, all P<0.001）. Positive coping styles played a moderating role in the relationships between perceived stress and sleep quality（P<0.001）, while negative coping styles had no moderating effect（P=0.676）. Conclusion Military aircrews have suboptimal sleep quality. The greater the stress, the poorer the sleep quality. Positive coping styles can mitigate the negative impact of stress on sleep quality.
Objective To analyze the relationships between sleep quality, mental state and quality of life of civil aviation aircrews in order to provide a reference for preventing these conditions. Methods The convenient sampling method, a general questionnaire, Pittsburgh Sleep Quality Index（PSQI）, Self-Rating Depression Scale（SDS）, Self-Rating Anxiety Scale（SAS）, and a 12-Item Short-Form Health Survey Scale（SF-12）were used to survey 395 aircrews of an airline, assess their sleep quality, and analyze the causes of sleep disorders and the correlations between sleep quality and depression, anxiety and quality of life. Results The incidence of sleep disorders in these aircrews was 28.6%, and flying over more than 4 time zones for more than 3 times in one month was a risk factor for sleep disorders（OR=2.790, 95%CI: 1.266~6.147, P=0.011）. Among these aircrews, 28.9% suffered from depression（114/395）and 7.8% anxiety（31/395）. Depression and anxiety were more common among aircrews with sleep disorders than among those with normal sleep（t=7.102, 5.044, both P<0.001）. The scores of sleep quality of aircrews were positively correlated with the scores of depression and anxiety（r=0.304, 0.216, both P<0.001）. The scores of general health, role-physical scores, role-emotional scores and those of bodily pain, mental health, vitality and social function of the aircrew with normal sleep were higher than those of the sleep disorder group（t=4.111-8.323, all P<0.001）. Conclusion The body height is a factor leading to sleep disorders in aircrews, and flying over more than 4 time zones three times or more in a month is a risk factor for sleep disorders. Sleep quality, depression and anxiety of aircrews are mutually causal and complicated in their correlations. Airlines should attach importance to sleep and mental health management of aircrews who are different in heights, fly across time zones and remain physically inactive.
Objective To find out about the incidence of thyroid nodules（TN）in naval pilots as well as factors related to lipid metabolism. Methods The results of thyroid ultrasound examination of naval pilots who had recuperated at our sanatorium between June 2019 and December 2021 were retrospectively analyzed to collect data and study the differences in blood lipid indicators between the TN group and the non-TN group. The distribution of TNs across naval pilots of different ages was analyzed while the correlations between blood lipid levels and the classification of TNs and the thyroid imaging reporting and data system（TI-RADS）were investigated. Results A total of 945 naval pilots were included in this study, with a thyroid nodule detection rate of 31.64%. The TN group was older than the non-TN group（t=3.332, P<0.05）, there was a statistically significant difference in detection rates among different age groups（χ2=21.196, P<0.01）. There was no statistically significant difference in blood lipid related indicators between the TN group and the non-TN group（P>0.05）. In groups with different blood lipid levels, the proportion of thyroid nodules classified was mostly TI-RADS 3. Conclusion Clinicians should attach importance to the screening of TNs in military pilots, keep track of malignant high-risk nodules with combined lipid abnormalities, clarify the nature of nodules early, and ensure early detection, diagnosis, and treatment of thyroid cancer.
Objective To study the relationships between postural control ability and cumulative fatigue under stress and to explore rapid methods for assessing fatigue. Methods Fifteen undergraduates from Shanghai University of Science and Technology who participated in the National Undergraduate Electronics Design Competition were enrolled to evaluate their postural control capabilities under fatigue and alertness. Participants were required to complete questionnaires assessing subjective fatigue and sleep duration and undergo dynamic balance tests and static balance tests on a balance testing device under both open-eye and closed-eye conditions. Statistical analysis was conducted using the Wilcoxon Signed-Rank Test. Results Data from subjective questionnaires and on sleep duration revealed a continuous increase in fatigue levels among subjects throughout the competition, indicating the cumulative nature of fatigue. The results of the balance ability assessments revealed statistically significant differences in such key metrics as the spiral trajectory accuracy（Z=2.329, P=0.020）, total length of open-eye trajectory（Z=2.272, P=0.023）, total length of closed-eye trajectory（Z=2.045, P=0.041）, and closed-eye envelope area（Z=2.329, P=0.020）. Conclusion There is a significant correlation between postural control ability and fatigue. The related metrics have demonstrated their utility as effective indicators for rapid assessment of fatigue status.
Objective To investigate the interventional effect of regular far-infrared irradiation on excessive proliferation of red blood cells at high altitudes via changes in red blood cell counts and regular far infrared irradiation. Methods After rigorous screening, the subjects were randomly divided into the far-infrared intervention group and control group. Patients with chronic high-altitude diseases were excluded. The intervention group received 50 days of far-infrared radiation at the intensity of 200 W once a day. Before and after interventions, peripheral blood was collected and biochemical analysis was conducted. Self-control and intra-group comparison methods were used for statistical analysis. Results Far infrared irradiation at a wavelength of 3.5~16.0 μm and an intensity above 200 W had no adverse effects on the subjects. The intervention group showed a significant decrease in systolic blood pressure, but an increase in blood oxygen saturation, diastolic blood pressure, and heart rate（Z=－3.184, －2.919, t=3.200, 3.983; P<0.001, =0.004, 0.007, 0.002）. After interventions, the red blood cell count in the control group was increased（P=0.001）. The results of intra-group comparison showed that there were statistically significant differences in hemoglobin, red blood cell counts, and HCT between the two groups before interventions（U=74.000, 49.000, 79.500, P=0.002, <0.001, =0.004）and after interventions（Hgroup=10.010, 13.370, 9.381, P=0.002, <0.001, 0.002）. Conclusion Whole-body far-infrared irradiation or local irradiation for more than 30 minutes per day for 50 days can effectively curb the increase in red blood cells caused by high-altitude exposure, suggesting that regular far-infrared radiation can effectively alleviate excessive proliferation of red blood cells caused by chronic diseases related to high altitudes.
Objective To analyze the data on the video head impulse test（vHIT）in patients diagnosed with bilateral vestibular weakness（BVW）via the caloric test in order to explore the alternative role of vHIT in diagnosis of BVW. Methods Data on vestibular examination of 106 vertigo patients was retrospectively collected. The patients were divided into the BVW group and normal vestibular function group（control group）according to the caloric test results. Results of vHIT were compared between the two groups. Results Once either unilateral or bilateral anomalies in the horizontal semicircular canals were deemed positive in a vHIT, statistically significant differences could be observed between vHIT and the caloric test for detecting BVW（P=0.002）. Furthermore, when only bilateral anomalies in the horizontal semicircular canals were considered positive, but negative in normal canals, vHIT still remained significantly different from the caloric test in identifying BVW（P=0.019）. The area under the ROC curve for saccade frequency was 0.748, the sensitivity 60.3% and specificity 87.3%. As for the semicircular canal gain loss, the area under curve was 0.841, sensitivity 87.2% and specificity 76.1%, compared with 0.706, 87.2% and 43.3% for asymmetrical gain. Conclusion vHIT should be prioritized as an initial screening tool for diagnosing BVW. When vHIT results show no abnormalities, a caloric test should be conducted to confirm the diagnosis, thereby ensuring that no potential BVW cases are missed.
Objective To investigate the effect of miRNA hsa-let-7b-5p on factor-related apoptosis（Fas）expressions and apoptosis of human umbilical vein endothelial cells（HUVECs）in high glucose state. Methods HUVECs were cultured and divided into the control group（at the medium glucose concentration of 5.5 mmol/L）, high glucose group（at the medium glucose concentration of 33.0 mmol/L）, high glucose+miRNA hsa-let-7b-5p mimic group（at the medium glucose concentration of 33.0 mmol/L+miRNA hsa-let-7b-5p mimic transfected cells）, and high glucose+miRNA hsa-let-7b-5p inhibitor group（at the medium glucose concentration of 33.0 mmol/L+miRNA hsa-let-7b-5p inhibitor transfected cells）. The proliferation viability of the four groups was detected by CCK8 assay, the protein level of Fas in each group of cells by Western blotting, and the mRNA levels of miRNA hsa-let-7b-5p and Fas in HUVECs by RT-PCR. TUNEL staining was performed to detect the apoptosis of cells in each group. Results The miRNA hsa-let-7b-5p mimic transfection increased the proliferative activity（P<0.001）but decreased the apoptotic rate（P<0.001）of the cells. The expression levels of Fas mRNA（P<0.001）and Fas protein（P<0.001）were decreased while the expression level of hsa-let-7b-5p mRNA was increased（P<0.001）. The miRNA hsa-let-7b-5p inhibitor transfection decreased the proliferative activity（P<0.001）but increased the apoptotic rate（P<0.001）of the cells. The expression levels of Fas mRNA（P<0.001）and Fas protein（P<0.001）were increased while that of hsa-let-7b-5p mRNA was decreased（P=0.001）. Conclusion In high glucose state, miRNA hsa-let-7b-5p may inhibit apoptosis of HUVECs and protect vascular endothelial cells against atherosclerosis.
Objective To investigate the expression and clinical significance of chemokine CXC subfamily receptor 4（CXCR4）in esophageal squamous cell carcinoma（ESCC）and its impact on biological characteristics of ESCC cell lines. Methods Bioinformatics methods were used to analyze the expression of CXCR4 in ESCC（82 cases）and normal tissues（1 456 cases）from the TCGA+GTEx dataset. Nine fresh ESCC tissues and their paired paracancerous tissues, 110 paraffin-embedded ESCC specimens, and 35 paired paracancerous tissues were collected. The mRNA levels of CXCR4 in 9 ESCC tissues and their paired paracancerous tissues were analyzed by qRT-PCR. The expression of CXCR4 in 110 ESCC and 35 paired paracancerous tissues was detected by immunohistochemistry. These tissues were divided into the CXCR4 low-expression group（46 cases）and the CXCR4 high-expression group（64 cases）. The differences in age, gender, TNM stage and lymph node metastasis between the two groups were studied. The proliferation, migration, and invasion abilities of cells with knocked down expressions of CXCR4 were detected using the cell counting kit-8（CCK-8 reagent）, scratch assay, and Transwell assay. The effect of knocking down CXCR4 expression on epithelial-mesenchymal transition（EMT）was examined by Western blot（WB）, immunofluorescence, and Transwell assay. Results The results of bioinformatics analysis showed that the expression of CXCR4 mRNA in ESCC tissues was higher than in normal esophageal tissues in the TCGA + GTEx dataset（t=9.524, P<0.001）. qRT-PCR analysis suggested that the mRNA level of CXCR4 in ESCC tissues was higher than in paracancerous tissues（t=9.967, P<0.001）. The CXCR4 protein expression level in ESCC tissues was higher than in paracancerous tissues（t=5.742, P=0.007）. There were statistically significant differences in TNM stage, N stage, and survival time between the CXCR4 low-expression group（46 cases）and the CXCR4 high-expression group（χ2=15.325, 13.628, both P<0.001; χ2=5.673, P=0.021）. The results of the CCK-8 assay indicated that the OD values of cells in the si-CXCR4 transfection group were lower than in the si-NC transfection group at 48 h and 72 h（P=0.019, 0.013）. Transwell assay showed that the numbers of migrating and invading cells in the si-CXCR4 transfection group were smaller than in the si-NC transfection group（t=5.790, 4.075, P=0.005, 0.008）. After knocking down CXCR4, the fluorescence intensity of E-cadherin expression increased, the fluorescence intensity of Vimentin decreased, and the EMT process induced by stromal cell-derived factor-1（SDF-1）was blocked. The numbers of migrating and invading cells in the si-CXCR4 transfection combined with SDF-1 treatment group were smaller than in the si-NC transfection combined with SDF-1 treatment group（F=14.290, 6.944, P=0.008, 0.044）. Conclusion Knocking down CXCR4 can inhibit the migration, invasion, and EMT process of ESCC cells. CXCR4 is highly expressed in ESCC tissues and is associated with poor prognosis, which can be used as a prognostic factor and a potential therapeutic target for ESCC.
Objective To investigate the influencing factors of sarcopenia in patients with type 2 diabetes mellitus and the correlations with axial bone mineral density and blood lipids. Methods A total of 181 patients with type 2 diabetes admitted to the Second People's Hospital of Hefei between January 2020 to June 2022 were selected as the subjects and were divided into the sarcopenia group（n=63）and non-sarcopenia group（n=118）. Spearman correlation analysis was conducted to analyze the correlations of the axial bone mineral density (BMD) and blood lipids with sarcopenia in type 2 diabetes patients while Logistic regression analysis was used to screen the risk factors for type 2 diabetes patients with sarcopenia. Results The results of correlation analysis showed that L1-L4 BMD, BMD of the left femoral neck and of the right femoral neck, triglyceride and high density lipoprotein were negatively correlated with type 2 diabetes patients with sarcopenia（r=－0.368-－0.227, all P<0.05）, while total cholesterol, low density lipoprotein and type 2 diabetes patients with sarcopenia were positively correlated（r=0.250, 0.226; P=0.001, 0.002）. Logistic regression analysis showed the results of osteoporosis（OR=40.906, 95%CI=6.246-267.914）, glycated hemoglobin A1c, HbA1c（OR=2.583, 95%CI=1.619~4.121）, total cholesterol（OR=3.555, 95%CI=1.852~6.823）, low density lipoprotein（OR=3.371, 95%CI=1.561~7.276 ）were risk factors for type 2 diabetes patients with sarcopenia. L1 BMD（OR=0.005, 95%CI=0.000~0.938）, BMD of the left femoral neck（OR=0.001, 95%CI=0.000~0.167）, and of the right femoral neck（OR=0.016, 95%CI=0.000~0.998）, parathyroid hormone, PTH）（OR=0.749, 95%CI=0.622~0.901）, triglyceride（OR=0.003, 95%CI=0.000~0.129）, high-density lipoprotein（OR=0.015, 95%CI=0.001~0.314）, skeletal muscle indexes（OR=0.199, 95%CI=0.081~0.489）were protective factors for type 2 diabetes patients with sarcopenia. Conclusion Axial bone mineral density and blood lipids are closely related to sarcopenia in patients with type 2 diabetes, suggesting that the axial bone mineral density and blood lipids in patients with type 2 diabetes should be monitored to prevent sarcopenia.
