Objective:To evaluate the effectiveness of anti-G straining maneuver (AGSM) in pilots by surface electromyography (sEMG), and to explore the relationships between characteristics of sEMG and anti-G endurance in pilots.Methods:Thirty-eight male high-performance fighter pilots who completed the human centrifuge test at the Air Force Medical Center were selected. Among them, 25 completed the 8.0 G for 10 s anti-G endurance test and 13 completed the 9.0 G for 10 s anti-G endurance test. The sEMG tester was used to keep track of the changes of sEMG in rectus abdominis, rectus femoris, anterior tibial and gastrocnemius muscles while pilots were engaged in AGSM. The anti-G endurance was evaluated according to the changes of visual fields and consciousness. The pilots were divided into 3 groups: the good vision and consciousness group, peripheral visual field narrowing group and endurance endpoint group. The differences in the integral electromyogram (iEMG), mean power frequency (MPF) and muscle input rates between the 3 groups were investigated.Results:A total of 25 pilots completed the 8.0 G for 10 s anti-G endurance test. Among them, 8 (32.0%) were in the good vision and consciousness group, 13 (52.0%) in the peripheral visual field narrowing group and 4 (16.0%) reached the endurance endpoint. Among the 13 pilots who completed the 9.0 G for 10 s anti-G endurance test, 3 (23.1%) were in the good vision and consciousness group, 6 (46.1%) in the peripheral visual field narrowing group, and 4 (30.8%) in the endurance endpoint group. The results of sEMG showed that the iEMG values of the anterior tibialis muscle in pilots under the 9.0 G for 10 s load were significantly different across endurance groups ( H=7.54, P=0.023), and that the iEMG values of the tibialis anterior muscle in the good vision and consciousness group were higher than those in the endurance endpoint group ( P=0.036). The negative slopes of MPF for the rectus abdominis, rectus femoris, anterior tibialis, and gastrocnemius muscles were higher in the good vision and consciousness group than in the other 2 groups, but the differences were not statistically significant ( P>0.05). During the 8.0 G for 10 s anti-G endurance test, there were significant differences in lower limb muscle contribution rates between the 3 groups ( F=4.19, P=0.029). The endurance endpoint group exhibited a lower contribution rate than the good vision and consciousness group ( P=0.025). During the 9.0 G for 10 s anti-G endurance test, there were significant differences in tibialis anterior muscle contribution rates between the 3 groups ( F=4.16, P=0.049). The endurance endpoint group demonstrated a lower contribution rate than the good vision and consciousness group ( P=0.049). Conclusions:The full and balanced activation of abdominal muscles and lower limb muscles, especially the effective mobilization of calf muscles, plays a pivotal role in improving pilots′ AGSM efficiency in high G environments.

Objective:To evaluate the effectiveness of anti-G straining maneuver (AGSM) in pilots by surface electromyography (sEMG), and to explore the relationships between characteristics of sEMG and anti-G endurance in pilots.Methods:Thirty-eight male high-performance fighter pilots who completed the human centrifuge test at the Air Force Medical Center were selected. Among them, 25 completed the 8.0 G for 10 s anti-G endurance test and 13 completed the 9.0 G for 10 s anti-G endurance test. The sEMG tester was used to keep track of the changes of sEMG in rectus abdominis, rectus femoris, anterior tibial and gastrocnemius muscles while pilots were engaged in AGSM. The anti-G endurance was evaluated according to the changes of visual fields and consciousness. The pilots were divided into 3 groups: the good vision and consciousness group, peripheral visual field narrowing group and endurance endpoint group. The differences in the integral electromyogram (iEMG), mean power frequency (MPF) and muscle input rates between the 3 groups were investigated.Results:A total of 25 pilots completed the 8.0 G for 10 s anti-G endurance test. Among them, 8 (32.0%) were in the good vision and consciousness group, 13 (52.0%) in the peripheral visual field narrowing group and 4 (16.0%) reached the endurance endpoint. Among the 13 pilots who completed the 9.0 G for 10 s anti-G endurance test, 3 (23.1%) were in the good vision and consciousness group, 6 (46.1%) in the peripheral visual field narrowing group, and 4 (30.8%) in the endurance endpoint group. The results of sEMG showed that the iEMG values of the anterior tibialis muscle in pilots under the 9.0 G for 10 s load were significantly different across endurance groups ( H=7.54, P=0.023), and that the iEMG values of the tibialis anterior muscle in the good vision and consciousness group were higher than those in the endurance endpoint group ( P=0.036). The negative slopes of MPF for the rectus abdominis, rectus femoris, anterior tibialis, and gastrocnemius muscles were higher in the good vision and consciousness group than in the other 2 groups, but the differences were not statistically significant ( P>0.05). During the 8.0 G for 10 s anti-G endurance test, there were significant differences in lower limb muscle contribution rates between the 3 groups ( F=4.19, P=0.029). The endurance endpoint group exhibited a lower contribution rate than the good vision and consciousness group ( P=0.025). During the 9.0 G for 10 s anti-G endurance test, there were significant differences in tibialis anterior muscle contribution rates between the 3 groups ( F=4.16, P=0.049). The endurance endpoint group demonstrated a lower contribution rate than the good vision and consciousness group ( P=0.049). Conclusions:The full and balanced activation of abdominal muscles and lower limb muscles, especially the effective mobilization of calf muscles, plays a pivotal role in improving pilots′ AGSM efficiency in high G environments.

Objective To explore basement membrane markers and potential drugs for treatment in idiopathic pulmona-ry fibrosis(IPF).Methods IPF-related datasets were downloaded from the Gene Expression Omnibus(GEO)database,processed to construct basement membrane gene expression matrices associated with IPF,and screened for differential basement membrane genes(DEBMs);DEBMs were enriched for function and pathways,and machine learning algorithms were used to ob-tain candidate signature genes,receiver operating characteristic(ROC)curves were used to identify signature genes and con-struct a nomogram.We performed ssGSEA analysis to explore the correlation between signature genes and immune cells and their functions and predicted the corresponding miRNAs and therapeutic drugs by signature genes.Results A total of 56 DEBMs were extracted;enrichment analysis showed that DEBMs were mainly enriched in"extracellular matrix tissue","extracellular structural tissue",etc.,and were closely related to"ECM-receptor interaction"and"local adhesion spot"pathways.The ma-chine learning has identified six candidate signature genes(TIMP3,P3H2,ITGA7,ITGA4,ADAMTS2,COL8A2),all of which meet the requirements of the signature genes by the ROC curve test,and the nomogram diagnostic value was outstanding(AUC=0.991 523);B cells and Macrophages in IPF were significantly different from the normal group.Finally,miRNAs were predicted to be dominated by miR-4305,miR-3684,progesterone,and tert-butyl hydroperoxide as therapeutic agents with strong relevance to IPF.Conclusion Signature genes and predictive miRNAs may serve as novel markers for IPF diagnosis,and pre-dictive drugs may be a potential source of drugs for treating IPF.

Objective To establish a scientific training program that takes into account both anaerobic and aerobic training for pilots,and to explore the appropriate ratio of aerobic and anaerobic training.Methods According to the physical examination standards for pilots,a total of 16 healthy subjects aged 18-24 were selected from two batches.The two batches of subjects were trained with different aerobic and anaerobic ratios.Training period was 3 months.The changes in cardiopulmonary function of the subjects before and after training were evaluated using the cardiopulmonary function exercise testing system(CPET),and the changes in anaerobic capacity were evaluated using changes in strength as an indicator.Results After training,the weight load of the subjects in the two training programs,including barbell squats,leg flexion and hard pull,and barbell under 10RM and 3RM,was significantly increased(P<0.001),and there was no statistically significant difference in anaerobic strength growth between the two groups.The results of CPET showed that the maximum load,maximum heart rate,and respiratory quotient in the two groups were significantly increased after than before the training(P<0.01).The maximum load(Experiment group 1:29.12±19.69,Experiment group 2:72.00±46.24)and respiratory quotient(Experiment grouop 1:0.11±0.09,Experiment group 2:0.28±0.16)of the subjects in experiment group 2 before and after training were greater than those in experiment group 1.The difference was statistically significant(P<0.05).Conclusion The anaerobic and aerobic capacities of the subjects in the experiment group 2 are effectively improved,indicating that ratio of aerobic and anaerobic of the training scheme is better.

Objective:To observe and analyze the risk factors of positive conjunctival capsule microbial culture in patients with intravitreal injection treatment (IVT) before treatment.Methods:A prospective study. A total of 1 092 patients who received IVT at the Vitreous Injection Center of Tianjin Medical University Eye Hospital from February 2021 to February 2024 were included in the study. Among them, 539 were males and 553 were females. The age was (62.29±13.61) years. Hypertension and diabetes were 661 and 576 cases, respectively. There were 742 cases of urban residence and 350 cases of rural residence. Three and one days before IVT, 364 patients received antibiotics and 364 patients did not receive antibiotics. Patients' gender, age, history of hypertension and diabetes, pre-IVT antibiotic eye drops use history, and differences in residence (town/country) were collected in detail. Samples were collected after the conjunctival sac was rinsed, and microbial culture was performed. The differences in conjunctival microbial culture positivity rates was compared between those who did not use antibiotic eye drops before IVT, those who used them 1 day before IVT, and those who used them 3 days before IVT. The positive rate of conjunctival sac microbial culture were compared among individuals of different ages, genders, with/without hypertension, with/without diabetes, with different IVT times, and from different living areas (urban/rural). The clinical baseline of positive conjunctival capsule bacterial culture was compared and observed. χ2 test was used to compare the positive rate of conjunctival capsule microbial culture among different clinical baselines. Logistic binary regression analysis was used to analyze the influencing factors. Results:Among the 1 092 patients, 54 cases (4.95%, 54/1 092) were positive for microbial culture of conjunctival sac. There was no significant difference ( P>0.05) in the positive rate of conjunctival sac microbial culture among patients of different ages ( χ2=5.599), gender ( χ2=0.549), residence ( χ2=0.153), with or without hypertension and diabetes ( χ2=3.545, 0.044), and with or without diabetic macular edema ( χ2=0.180). There was no significant difference ( P>0.05) in the positive rate of conjunctival sac microbial culture between patients with different numbers of IVT ( χ2=0.961) or between those who received antibiotic eye drops before IVT and those who did not ( χ2=5.600). Logistic binary regression analysis showed that none of the above factors were risk factors for positive conjunctival capsule microbial culture ( P>0.05). No infective endophthalmitis occurred in all patients during the observation period. Conclusion:The use of antibiotics before IVT is not the decisive factor for positive microbial culture in conjunctival sac.

Objective:To explore whether Corona Virus Disease 2019 (COVID-19) has any impact on human centrifuge training of flying cadets and to provide references to the human centrifuge training for the recovered flying personnel by comparing the changes of flying cadets′ G-tolerance and physiological indicators in human centrifuge training.Methods:Twelve flying cadets who underwent the current batch of human centrifuge training in 2022 were selected and divided into rehabilitation group and control group according to whether they had been infected with COVID-19, with 6 in each group. The rapid G onset rate (ROR) and gradual G onset rate (GOR) were respectively chosen for human centrifuge test. At the same time, the changes of their heart rate and respiratory rate during the tests were recorded, and the G-tolerance situations of the subjects were collected.Results:The average relaxed G-tolerance under GOR (GOR tolerance 1) was (4.2±0.8) G in rehabilitation group, and their average anti-G straining maneuver aided G-tolerance under GOR (GOR tolerance 2) was (5.7±0.6) G. Compared with that of the control group, there was no significant difference in GOR tolerance 1 and GOR tolerance 2 (both P>0.05). There was no significant changes in heart rate and respiratory rate in ROR and GOR human centrifuge tests between 2 groups (all P>0.05). Conclusions:COVID-19 didn't impact the recovered flying cadets' performance in human centrifuge training, as well as the anti-G straining maneuver effect and cardiovascular regulation.

Objective:To explore the role and relationship between oxidative stress and immune infiltration in idiopathic pul-monary fibrosis(IPF),and to predict the relevant therapeutic herbal medicines and active ingredients.Methods:GSE10667 gene expression profiles were downloaded from GEO database to obtain differential expression genes,differential expression of oxidative stress genes(DEOSGs)were identified in combination with oxidative stress genes.GSEA was used to evaluate the pathways and biologi-cal processes in IPF,and GO,KEGG and PPI network analysis were performed on DEOSGs.Candidate central genes were derived from PPI results and CytoHubba,and GSE110147 was validated as an independent group to identify central genes;in addition,the immune microenvironment of samples was evaluated using CIBERSORTF,and correlation between central gene levels and relative proportion of immune cells was explored;finally,therapeutic herbal medicines and components were predicted by central genes,and mole-cular docking verification was carried out.Results:A total of 51 DEOSGs,four central genes(ICAM-1,APOE,MMP-1,TGF-β2)were obtained;DEOSGs were mainly related to oxidative stress,immune response,etc;four central gene levels were closely correlated with 8 relative proportions of immune cells;therapeutic herbal medicines included 4 flavors such as Huangqi and Chuanxiong,and the active ingredients included 8 kinds of β-carotene,etc,the molecular docking results were stable.Conclusion:Oxidative stress and immune firing are exist in IPF,and oxidative stress may be recognized by immune cells or directly activate immune cells.

Objective:To observe the differences in the positive rate of conjunctival sac microbial culture after different methods of preventing infection before intravitreal injection (IVI).Methods:A prospective case-control study. A total of 1 200 participants with fundus diseases who received IVI injection at Tianjin Medical University Eye Hospital from July 2021 to December 2023 were included. Patients were randomly divided into 6 groups according to eye spot with antibiotic solution 3, 1 and 0 days before IVI and local eye disinfection with povidone-iodine (PVI) 3 min and 30 s before IVI: the first 3 days of antibiotics+3 min PVI group, the first 1 day of antibiotics+3 min PVI group, the first 0 days of antibiotics+3 min PVI group, the first 3 days of antibiotics+30 s PVI group, the first 1 day of antibiotics+30 s PVI group, the first 0 days of antibiotics+30 s PVI group, there were 200 cases in each group. Microbial sampling and cultivation of conjunctival sac were conducted before IVI to compare the differences in positive rates among different groups. Multiple group comparisons were conducted using one-way analysis of variance. The comparison of count data is conducted using χ2 test. Results:Among the 1 200 patients, there were 566 males and 634 females. Age (62.59±13.44) years old. There were 397 cases of diabetes and 482 cases of hypertension. IVI frequency (2.35±2.34). 64 cases were positive for conjunctival sac culture before IVI. The age ( F=1.468), sex composition ratio ( χ2=2.876), diabetes ( χ2=10.002), hypertension ( χ2=6.019), times of IVI ( χ2=4.507), and positive rate of conjunctival sac bacterial culture ( χ2 =6.272) of patients in each group had no statistical significance ( P>0.05). Using the duration of antibiotic application before IVI as a stratified factor, there was no statistically significant difference in the positive rate of conjunctival sac culture between groups with different durations of antibiotic application before IVI [ χ2=0.414, P=0.52, combined odds ratio ( OR)=0.819, 95% confidence interval ( CI) 0.493-1.360]. Using the duration of PVI application as a stratified factor, there was no statistically significant difference in the positive rate of conjunctival sac culture between different PVI disinfection times [ χ2=0.000, P=1.000, combined OR=1.00, 95% CI 0.503-1.988]. Conclusions:Pre IVI treatment with 0.5% PVI for 30 s can inhibit the growth of microbial colonies in the conjunctival sac. The application of local antibiotic eye fluid in the anterior eye of IVI cannot reduce the positive rate of conjunctival sac bacteria.

Objective:To discuss the application of gradual-onset rate run (GOR) of human centrifuge on G-tolerance evaluation and training by analyzing the training results of (student) pilots in GOR centrifuge run.Methods:The G-tolerance and anti-G straining maneuver effect of 440 student pilots and 368 pilots participated centrifuge training in recent years were analyzed. The (student) pilots were grouped by age (20-25 years,26-30 years,31-35 years,36-40 years, >40 years). The 392 student pilots and 335 pilots who completed rapid onset rate run (ROR) were divided into 8 G 10 s training high G tolerance group (group A), 8 G 10 s training low G tolerance group (group B), 9 G 10 s training high G tolerance group (group C) and 9 G 10 s training low G tolerance group (group D) according to pass the 8 G 10 s or 9 G 10 s run one-time or not. The relation of G-tolerance and anti-G straining maneuver effect of GOR to ROR was discussed.Results:The average distribution range of relaxed G-tolerance under GOR (GOR tolerance 1) was (4.1±0.7) G, and the average distribution range of anti-G straining maneuver aided G-tolerance under GOR (GOR tolerance 2) was (6.2±0.8) G. The average HP anti-G straining maneuver effect was (2.1±0.6) G. There was a significant difference in GOR tolerance 1 ( H=11.94, P=0.018), no significant difference in GOR tolerance 2 ( H=4.80, P=0.308), and a significant difference in the effect of HP anti-G straining maneuver among pilots in different age groups ( F=3.01, P=0.018). The effect of HP anti-G straining maneuver in the age group over 40 years old was greater than that in other age groups ( P=0.027, 0.034, 0.009, 0.006). There was no significant difference in GOR tolerance 1, GOR tolerance 2 and HP anti-G straining maneuver effect between pilots and student pilots (all P>0.05). There were significant differences in GOR tolerance 2 ( H=15.38, P=0.002) and the effect of HP anti-G straining maneuver ( H=8.22, P=0.041) among group A, group B, group C and group D. The GOR tolerance 2 of group B was lower than that of other anti-G tolerance groups ( P=0.003, 0.001, 0.040). Conclusions:The centrifuge GOR training could reflect the G-tolerance and anti-G straining maneuver effect of (student) pilots and provide references for predicting the human centrifuge training result and improving accelerate training and tolerance evaluating.

Objective:To observe and analyze the risk factors of positive conjunctival capsule microbial culture in patients with intravitreal injection treatment (IVT) before treatment.Methods:A prospective study. A total of 1 092 patients who received IVT at the Vitreous Injection Center of Tianjin Medical University Eye Hospital from February 2021 to February 2024 were included in the study. Among them, 539 were males and 553 were females. The age was (62.29±13.61) years. Hypertension and diabetes were 661 and 576 cases, respectively. There were 742 cases of urban residence and 350 cases of rural residence. Three and one days before IVT, 364 patients received antibiotics and 364 patients did not receive antibiotics. Patients' gender, age, history of hypertension and diabetes, pre-IVT antibiotic eye drops use history, and differences in residence (town/country) were collected in detail. Samples were collected after the conjunctival sac was rinsed, and microbial culture was performed. The differences in conjunctival microbial culture positivity rates was compared between those who did not use antibiotic eye drops before IVT, those who used them 1 day before IVT, and those who used them 3 days before IVT. The positive rate of conjunctival sac microbial culture were compared among individuals of different ages, genders, with/without hypertension, with/without diabetes, with different IVT times, and from different living areas (urban/rural). The clinical baseline of positive conjunctival capsule bacterial culture was compared and observed. χ2 test was used to compare the positive rate of conjunctival capsule microbial culture among different clinical baselines. Logistic binary regression analysis was used to analyze the influencing factors. Results:Among the 1 092 patients, 54 cases (4.95%, 54/1 092) were positive for microbial culture of conjunctival sac. There was no significant difference ( P>0.05) in the positive rate of conjunctival sac microbial culture among patients of different ages ( χ2=5.599), gender ( χ2=0.549), residence ( χ2=0.153), with or without hypertension and diabetes ( χ2=3.545, 0.044), and with or without diabetic macular edema ( χ2=0.180). There was no significant difference ( P>0.05) in the positive rate of conjunctival sac microbial culture between patients with different numbers of IVT ( χ2=0.961) or between those who received antibiotic eye drops before IVT and those who did not ( χ2=5.600). Logistic binary regression analysis showed that none of the above factors were risk factors for positive conjunctival capsule microbial culture ( P>0.05). No infective endophthalmitis occurred in all patients during the observation period. Conclusion:The use of antibiotics before IVT is not the decisive factor for positive microbial culture in conjunctival sac.