Objective To investigate the mechanism of influence of different oxygen concentrations on the composting process of solid biomass waste to determine the optimal oxygen parameters for future controlled ecological life support system(CELSS)solid waste treatment on extraterrestrial planet bases and enhance oxygen utilization efficiency.Methods Using the self-developed solid waste bioreactor test system,aerobic composting experiments were conducted on wheat straw and simulated manure with three different oxygen concentrations of 10%,15%,and 21%.Gas components(O2,NH3,CH4,and N2O)and material maturity indicators(moisture content,dissolved organic carbon,NH4+-N,and seed germination index)were regularly analyzed throughout the treatment process.Results The 15%O2 treatment group had the highest oxygen consumption,the lowest emissions of NH3 and N2O,the best degradation effect of dissolved organic carbon content and the higher NH4+-N content.CH4 emissions in the three treatment groups were all at a low level.At the end of composting,the moisture content of the products in the 10%O2 and 15%O2 treatment groups was all higher than 74%,and the water-holding capacity was the best.The seed germination indexes in the 3 treatment group were 86.64%,123.81%,and 97.98%,respectively.Conclusion Com pared to oxygen concentrations of 10%and 21%,the 15%oxygen concentration can effectively reduce the emission of NH3 and N2O.It also improves nitrogen and water retention,enhances dissolved organic carbon degradation effects,and results in higher maturity levels.

Objective To develop a Traditional Chinese Medicine(TCM)syndrome diagnosis scale suitable for evaluating the overall health status of participants in long-term simulated weightlessness experiments,and preliminarily evaluate its reliability and validity.Methods Based on the understanding of the pathogenesis of TCM in different stages of long-term manned spaceflight,a scale was developed through literature research and expert consultation.Test-retest reliability and internal consistency coefficient were used to test the reliability of the scale.Item analysis and factor principal component analysis were used to evaluate the validity of the scale,and a rotating component matrix was used to analyze the correlation between each item and dimension using 36 volunteers in a 90 days head down bed rest experiment as the research subjects.Results The scale contains eight dimensions and 57 items.The reliability analysis showed that the correlation coefficient of the total score of the scale for the first and second tests of 30 participants was 0.889,indicating high stability of the scale.The Cronbach coefficient of the scale was 0.934,indicating very good internal consistency.The split half reliability after correction was 0.858,indicating a high reliability of the scale.The validity analysis showed that the difference between the high score group and the low score one for each of the 57 items was statistically significant(P<0.01),and the Pearson correlation coefficient between each item and the total score of the scale was greater than 0.4(P<0.001).The cumulative contribution rate of 8 common factors extracted using principal component factor analysis was 55.293%,and the results of rotating component matrix analysis,after applying TCM theory and expert feedback,had a coincidence of up to 87.5%with the initial 8 dimensions,indicating good structural validity of the scale.Conclusion The scale has good reliability and validity,and can diagnose TCM syndromes.It is suitable for long-term simulated weightlessness experiment and provides an objective and quantitative new method for evaluating the subjective feelings of participants.

Objective To develop a mental fatigue detection method for spaceflight environments in response to the mental fatigue problem that may arise during the on-orbit period of astronauts.Methods In the ground-based research,we used a 36-hour sleep deprivation experiment to induce mental fatigue state.Then the electroencephalogram(EEG)data and questionnaire scores were collected from 45 subjects.Finally,a series of EEG features relevant to mental fatigue were calculated and a mental fatigue detection method constructed with Random Forest Classifier to differentiate the mental fatigue level.Results The average accuracy over 85%was achieved in both ground-based and space-based experimental data and each evaluation index had consistent trend.Conclusion The mental fatigue detection method based on EEG signals is suited to the differences in environment and tasks,and shows precise and stable performance in both ground-based experiment and space-based one,which is feasible to be applied in spaceflight environments in the future.

Objective To investigate the protective effect of Qianggukangwei Recipe(QG)on myotube cell atrophy induced by simulated microgravity effect(SMG).Methods The induced differentiation mouse myotube cells(C2C12 cells)were divided into six groups.Then the 48h simulated microgravity effect(SMG)model of mouse myotube cells was established by three-dimensional gyrotron(48h-SMG group).The cells in 3 groups were treated with 2.50,1.25,0.625 mg/mL QG.The cells in the left group were treated with 2.70 μg/mL alendronate sodium as positive control group.The levels of oxidative and inflammatory factors in myotube cells were detected by kits.The protein expression levels of NF-κB/IκB protein decomposition pathway and IGF-1/PI3K/Akt protein synthesis pathway were detected by Western blotting.The IGF-1/PI3K/Akt pathway was verified by 7 μmol/L of IGF-1 inhibitor.Results As compared with the control group,oxidation and inflammation levels in myotube cells increased significantly(P<0.05).The protein expression levels of IKK,NF-κB,and MURF-1 were significantly increased by 19.9%±6.1%,189.3%±15.9%,445.0%±46.1%,and IκB was significantly decreased by 26.5%±0.1%(P<0.05).The levels of IGF-1,PI3K,p-Akt/Akt and mTOR in the IGF-1/PI3K/Akt pathway were decreased by 23.6%±0.5%,30.7%±2.7%,13.3%±1.1%,21.0%±1.6%(P<0.05).The three doses of QG could and reduce the level of cellular oxidative stress and inflammation(P<0.05).QG could also activate the IGF-1/PI3K/Akt pathway and inhibit the NF-κB/IκB pathway.Among them,the high dose of QG(2.50 mg/mL)significantly decreased the protein expression levels of IKK,NF-κB and MURF-1 by 39.9%±2.4%,48.6%±0.1%,70.0%±2.1%(P<0.05),and significantly increased the expression levels of IGF-1,PI3K,mTOR and Akt phosphorylation by 43.1%±1.1%,100.0%±7.7%,71.8%±2.5%,95.2%±12.8%(P<0.05).Conclusion QG can significantly alleviate myotube cell atrophy induced by SMG effect by regulating relevant protein synthesis and degradation pathways.

Objective To rapidly visualize and detect the extracellular vesicles of glial cells in a simulated space environment.Methods By using 2,5 Gy irradiation and 12,24 h microgravity treatment,a damage model of glial cells was established in a simulated space environment.Exosomes extracted from conditioned media with reagent kits were transferred to neurons to elucidate the impact of glial cells on neurons.By performing live-cell fluorescence labeling of exosomes,a visualization monitoring scheme based on fluorescence intensity analysis was developed to characterize the release patterns of extracellular vesicles.The release patterns of exosomes were represented by the fluorescence intensity of the conditioned media.The effects of different storage conditions and duration on the quantity and size of exosomes were investigated.Results The exosomes released from damaged glial cells in the simulated space environment could to some extent protect neurons,with exosomes playing a decisive role in this process,and the neurosystem exosome visualization detection scheme was consistent with the traditional exosome validation scheme.An empirical curve for exosome quantity and size was established for semi-quantitative analysis,providing a new approach for rapid detection of exosomes in cell culture media.Furthermore,the optimal storage conditions for culture medium samples were clarified,laying the foundation for ground/space-based online analysis of culture medium samples after spaceflight.Conclusion Exosome rapid detection and analysis can be achieved through fluorescence labeling and utilized to investigate glial cell injury in a simulated space environment.

Objective Motortherapy and neck muscle resistance training are used to study the effects of resistance training on neck pain level and surface myoelectric activity of student pilots of carrier aircraft.Methods We conducted an intervention experiment on the neck pain of the carrier-based aircraft student pilots.The experiment period was 3 months.The experimental subjects were male carrier-based aircraft student pilots aged from 23 to 35.Questionnaires,including the Cervical Dysfunction Index and the Chinese Physical Activity Questionnaire,were issued,followed by cervical muscle function tests,including cervical maximum muscle strength,cervical range of motion,and surface electromyography tests.The experimental subjects were randomly divided into the control group and the resistance training group,with 8 in each.The subjects in the control group recieved usual military training.Those in the resistance training group recieved targeted training programs developed by using the self-developed cervical spondylosis prevention training device in addition to usual military training.The programs were carried out for resistance training three times a week for 20 minutes in each.Cervical maximum muscle strength,cervical range of motion,and surface electromyography were tested again before the end of the intervention experiment.The data were analyzed by SPSS 22.0.The results were expressed by mean±standard deviation((-x)±s).P<0.05 was considered statistically significant.Results(1)After 12-week intervention,resistance training had a significant effect on visual pain analog scale(VAS).(2)After the intervention,the comparison results of the subjects'cervical spine dysfunction index(NDI)before and after their own tests showed that the level of cervical spine dysfunction was significantly improved.(3)After the intervention,the results of inter-group comparison of the subjects'own joint motion showed that the self-variation difference of the subjects in the resistance training group was significantly different in forward flexion,backward extension,left flexion,right flexion,right rotation and left rotation.(4)After the intervention,the comparison results between the two groups of subjects'own neck muscle strength showed that there was no significant difference in the self-change of the six movements of subjects in the resistance training group.(5)The root mean square(RMS)values in the four movement tests of flexion,extension,flexion and flexion before and after the intervention in the resistance training group showed no significant difference between the left and right sternocleidomastoid muscle and the right and right trapezius muscle.(6)The integrated electromyography(iEMG)in the four movement tests of flexion,extension,flexion and flexion before and after the intervention in the resistance training group showed no significant difference between the left and right sternocleidomastoid muscle and the right and right trapezius muscle superior bundle.Conclusion After 12 weeks of resistance training,VAS scores and NDI scores of resistance training subjects are significantly reduced,indicating that resistance training can alleviate neck pain and improve cervical spine dysfunction.12-week resistance training can enhance the strength of neck muscles of carrier-based aircraft student pilots and improve the anti-fatigue ability of neck muscles.Meanwhile,it can enhance the range of motion of neck joints,improve the load of the deep and shallow muscle fibers of the four tested muscles in the neck and optimize the activation mode of the deep and shallow muscles in the neck.

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 Neuromuscular electrical stimulation(NMES)-evoked kinesthetic information in muscle spindle can be purely extracted from the mixed motor and sensory afferents using Ischemic nerve block(INB).This study aims to investigate the somatosensory cortical response evoked by NMES activating muscle spindle afferents in forearm.Methods All subjects performed four experimental tasks designed according to a 2×2 factors,including one factor of the INB state(without INB and within INB)and the other of the stimulation intensity(above and below motor threshold).During the experiment,we recorded EEG data with 64 channels and then beta event-related desynchronization(Beta ERD)were utilized quantize somatosensory cortical excitability evoked by the tasks.The subjective perception about the sensation and movement of the right hand were evaluated by a psychophysical test after the right wrist was performed by INB.Results INB significantly reduced beta ERD on the contralateral somatosensory cortex evoked by NMES above the motor threshold,and there was significant difference of NMES-evoked beta ERD values on the contralateral somatosensory cortex between above and below motor threshold.Meanwhile,contralateral dominance of NMES-evoked beta ERD on the somatosensory cortex was transferred to ipsilateral hemisphere under INB.Conclusion INB can significantly reduce NMES-evoked somatosensory cortical response above motor threshold and decrease cortical perception on the stimulus intensity,which may be due to INB resulting in rapid functional reorganization of somatosensory cortex.

Objective This study uses whole-genome methylation capture sequencing technology to screen differential sites and regions of gene methylation in mouse liver and colon under simulated weightlessness conditions to reveal the specific impact of weightlessness on gene methylation.Methods Six 8-week-old male C57BL/6J mice were randomized into the tail suspension group and the control group,with 3 in each.The 3 mice in the tail suspension group recieved tail suspension for simulated weightlessness for 42 days.After the experiment,DNA was extracted from liver and colon tissue and analyzed using genome-wide methylation capture sequencing technology.Results DNA analysis of liver tissue showed that a total of 7 517 differentially methylated sites and 997 differentially methylated regions were found,involving 4 892 genes.DNA analysis of colon tissue revealed 70 340 differentially methylated sites and 12 004 differentially methylated regions,affecting 12 877 genes.GO and KEGG path analysis revealed that these differentially methylated genes were mainly involved in protein binding,cell adhesion,cell activation,and various metabolic pathways.Conclusion This study successfully identified differential methylation sites and regions in mouse liver and colon under simulated weightlessness conditions through high-throughput sequencing technology.These findings help to further understand the impact of long-term space residence on biological gene methylation.It provides new research ideas for the prevention and early treatment of space flight-related diseases.

Objective To explore the intervention effect of badminton exercise on neck pain in naval carrier-based aircraft flight trainees,and provide data support for the prevention and relief of neck pain in these trainees.Methods A total of 16 naval carrier-based aircraft flight trainees were selected as subjects based on inclusion and exclusion criteria,and randomly divided into the sports rehabilitation group and the control group,with eight participants in each group.The sports rehabilitation group engaged in badminton exercise three times a week for one hour each time,in addition to their regular military training.The control group received no other interventions apart from their regular military training.Neck Disability Index(NDI),Visual Analog Scale(VAS)for pain simulation,Cervical Range of Motion(CROM),maximum neck strength,Root Mean Square(RMS)value of surface electromyographic signals,and integrated electromyography(iEMG)values were used as evaluation indexes for the intervention effect of neck pain.Results There was a significant difference in NDI scores among members of the sports rehabilitation group before and after intervention(P<0.05).However,there was no significant difference observed in NDI scores among members of the control group before and after intervention(P>0.05).Furthermore,there was a significant difference in VAS scores among members of the sports rehabilitation group before and after intervention(P<0.01).The VAS scores of the control group members showed no significant difference compared to pre-intervention testing(P>0.05).The maximum range of motion in all directions increased for the exercise rehabilitation group,with significant differences observed in left and right flexion(P<0.05),but no significant differences were found in other directions(P>0.05)compared to pre-intervention levels.There was no significant change in maximum range of motion within the control group before and after intervention(P>0.05).The exercise rehabilitation group demonstrated a significant increase in neck muscle strength during forward flexion,backward extension,left flexion(P<0.01),and right flexion as well as left and right rotation values(P<0.05)compared to pre-intervention levels.There was no significant difference observed between RMS values on both sides of the sternocleidomastoid muscles during movement in four different directions for the exercise rehabilitation group(P>0.05).However,there was a significant difference observed on the left side of the upper trapezius muscle during forward and rightward movements(P<0.05),but not during backward or leftward movements(P>0.05).No statistically significant differences were found among any direction's iEMG values before or after intervention for four muscles tested except that iEMG value increased slightly without significance after intervention when performing forward bending,backward extension and rightward bending exercises within exercise rehabilitation groups(P>0.05).Conclusion After badminton training,neck pain among carrier-based fighter pilots is allivated while cervical dysfunction recovers somewhat.Furthermore,their neck flexibility increases along with their neck muscle strength while deep muscles are activated to maintain stability to effectively enhance fatigue resistance capacity within these muscle groups around their necks.