Military flying labor hygiene is a discipline that focuses on influences of special flight environment and labor condition on human body and related prevent measures, with the core of flight fatigue. Health information and technique training can help flight surgeons to enhance professional competency and improve the prevention and recovery of military flying fatigue. The course construction of teaching system in this study included survey of demand, arrangement of content, identification of strategy, determination of evaluation, and feedback of results. Meanwhile, the textbook compilation, cultivation of teaching team and construction of laboratory were also needed. After a 4-year practice, a formal teaching system has been established and its teaching effectiveness has basically fulfilled the professional requirement for flight surgeons.

Objective To compare the National Aeronautics and Space Administration-task load index (NASA-TLX) scores and the heart rate variability (HRV) of the female pilot cadets under different task conditions and to preliminarily investigate the characteristics of flight mental workload in females . Methods Two factors repeated measurement design was applied in this study .Twenty female pilot cadets of a flight college were chosen as subjects .Their ECG data was collected under the baseline status that they were in theoretical education and the states of preflight , taking off , approaching and landing in simulated and real flying tasks by KF1 physiological parameter recorder . The NASA-TLX scores were used to evaluate the subjective mental workload of the female cadets under baseline status and in all flying stages .The collected data are analyzed by repeated measurement ANOVA and the trends of changes in different flight stages were analyzed by Spearman's non-parameter correlation test . Results Eighteen subjects'NASA-TLX scores and 10 subjects'HR and HRV data were valid .① In analysis of the main effects of task type factors ,18 female pilot cadets'NASA-TLX scores showed significant variance between different tasks (F＝ 8 .294 , P＜0 .01) .The grand average scores both in simulated flight task (49 .47 ± 22 .69) and in real flight task (49 .68 ± 16.85)weresignificantlyhigherthanthatofbaselinestatus [(30.85±13.97);t＝3.506,3.547,P＜0 .05] .The heart rates of 10 female pilot cadets showed statistical significance between different tasks (F＝14 .615 , P＜0 .01) .The average heart rate in simulated flight task [(84 .70 ± 6 .89)beats/min] and in real flight task [(87 .73 ± 8 .79)beats/min] was also significantly higher than that of baseline status [(73 .70 ± 6 .15)beats/min ;t＝4 .029 ,5 .137 ,P＜0 .05] .②At the stage of landing ,NASA-TLX scores of 18 female flight cadets in real flight task (61 .70 ± 13 .15) and in simulated task (60 .54 ± 21.05)weresignificantlyhigherthanthatofbaselinestatus [(30.85±13.97);t＝3.506,3.547,P＜0 .05] .The HRV indexes of 10 female cadets ,including normalized unit low frequency (LFnu) , normalized unit high frequency (HFnu) ,ratio of low and high frequency bands (LF/HF) ,varied significantly in different types of task at the landing stage (F＝9 .015～12 .275 , P＜0 .01) .The LFnu in simulated flight [(90 .88 ± 4 .44)% ] and real flight tasks [(77 .22 ± 12 .04)% ] was higher than that of baseline status [(63 .75 ± 16 .87)% ;] (t＝4 .957 ,2 .462 ,P＜0 .05) ,and the HFnu of the two flight tasks [(9 .11 ± 4 .52)% ,(22 .78 ± 12 .04)% ] was lower than that of baseline status [(36 .25 ± 16 .87)% ;t＝4 .955 ,2 .460 ,P＜0 .05] .The LF/HF in this flight stage showed significant difference between simulated task (13 .51 ± 9 .51) and baseline status [(2 .40 ± 1 .66) ; t＝ 4 .088 , P＜ 0 .05] .③Both in the simulated and real flight tasks ,the NASA-TLX scores of 18 female flight cadets showed rising trend with the flight stage progress (ρ＝0 .328 ,0 .537 ,P＜0 .01) .The rising trends were also found on the LFnu and LF/HF of 10 female flight cadets (ρ＝ 0 .450～0 .631 , P＜ 0 .01) while the descending trends with flight stage progress were found on HFnu in both tasks (ρ＝ - 0 .631 ,-0 .450 ,P＜0 .01) . Conclusions The mental workload of female pilot cadets significantly increases in flight tasks as comparing to the baseline status and is significantly higher in landing stage than before flight .The simulated flight task can provide female pilot cadets basically the same mental workload as the real flight task .It is meaningful to pilot's training and related researches .

Objective To compare the National Aeronautics and Space Administration-task load index (NASA-TLX) scores and the heart rate variability (HRV) of the female pilot cadets under different task conditions and to preliminarily investigate the characteristics of flight mental workload in females . Methods Two factors repeated measurement design was applied in this study .Twenty female pilot cadets of a flight college were chosen as subjects .Their ECG data was collected under the baseline status that they were in theoretical education and the states of preflight , taking off , approaching and landing in simulated and real flying tasks by KF1 physiological parameter recorder . The NASA-TLX scores were used to evaluate the subjective mental workload of the female cadets under baseline status and in all flying stages .The collected data are analyzed by repeated measurement ANOVA and the trends of changes in different flight stages were analyzed by Spearman's non-parameter correlation test . Results Eighteen subjects'NASA-TLX scores and 10 subjects'HR and HRV data were valid .① In analysis of the main effects of task type factors ,18 female pilot cadets'NASA-TLX scores showed significant variance between different tasks (F＝ 8 .294 , P＜0 .01) .The grand average scores both in simulated flight task (49 .47 ± 22 .69) and in real flight task (49 .68 ± 16.85)weresignificantlyhigherthanthatofbaselinestatus [(30.85±13.97);t＝3.506,3.547,P＜0 .05] .The heart rates of 10 female pilot cadets showed statistical significance between different tasks (F＝14 .615 , P＜0 .01) .The average heart rate in simulated flight task [(84 .70 ± 6 .89)beats/min] and in real flight task [(87 .73 ± 8 .79)beats/min] was also significantly higher than that of baseline status [(73 .70 ± 6 .15)beats/min ;t＝4 .029 ,5 .137 ,P＜0 .05] .②At the stage of landing ,NASA-TLX scores of 18 female flight cadets in real flight task (61 .70 ± 13 .15) and in simulated task (60 .54 ± 21.05)weresignificantlyhigherthanthatofbaselinestatus [(30.85±13.97);t＝3.506,3.547,P＜0 .05] .The HRV indexes of 10 female cadets ,including normalized unit low frequency (LFnu) , normalized unit high frequency (HFnu) ,ratio of low and high frequency bands (LF/HF) ,varied significantly in different types of task at the landing stage (F＝9 .015～12 .275 , P＜0 .01) .The LFnu in simulated flight [(90 .88 ± 4 .44)% ] and real flight tasks [(77 .22 ± 12 .04)% ] was higher than that of baseline status [(63 .75 ± 16 .87)% ;] (t＝4 .957 ,2 .462 ,P＜0 .05) ,and the HFnu of the two flight tasks [(9 .11 ± 4 .52)% ,(22 .78 ± 12 .04)% ] was lower than that of baseline status [(36 .25 ± 16 .87)% ;t＝4 .955 ,2 .460 ,P＜0 .05] .The LF/HF in this flight stage showed significant difference between simulated task (13 .51 ± 9 .51) and baseline status [(2 .40 ± 1 .66) ; t＝ 4 .088 , P＜ 0 .05] .③Both in the simulated and real flight tasks ,the NASA-TLX scores of 18 female flight cadets showed rising trend with the flight stage progress (ρ＝0 .328 ,0 .537 ,P＜0 .01) .The rising trends were also found on the LFnu and LF/HF of 10 female flight cadets (ρ＝ 0 .450～0 .631 , P＜ 0 .01) while the descending trends with flight stage progress were found on HFnu in both tasks (ρ＝ - 0 .631 ,-0 .450 ,P＜0 .01) . Conclusions The mental workload of female pilot cadets significantly increases in flight tasks as comparing to the baseline status and is significantly higher in landing stage than before flight .The simulated flight task can provide female pilot cadets basically the same mental workload as the real flight task .It is meaningful to pilot's training and related researches .

Objective:To investigate the changes of gene or protein expression and activity of matrix metalloprotein9 (MMP9) and tissue inhibitor ofmetalloproteinasel (TIMP1) in the carotid artery (CA) of 4 wk hindlimb unweighted rat.Methods:A 4 weeks(wk) hindlimb unweighted (HU) rat model was used to simulate the effect of weightlessness on the cardiovascular system.Transmission electron microscopy was used to detect the content of ECM.Reverse transcriptase polymerase chain reaction(RT-PCR) was conducted to measure the mRNA content MMP and TIMP1.Immunohistochemistry and Western blot technique were used to measure the protein abundance.Gelatin zymography was carried out to detect the activity of MMP9.Results:Compared to the control group (CON),the area of ECM was enhanced (P＜0.05) and the content of collage fiber was increased (P＜0.05) in the CA of HU rats;moreover,HU did not affect the mRNA expression of MMP9,but significantly reduced the protein content (P＜0.05) or enzymatic activity (P＜0.05).Accordingly,the mRNA or protein expression of TIMP1 in the CA was significantly increased by HU (P＜0.05).Conclusion:Simulated weightlessness caused imbalance between MMP and TIMP1 expression,which might contribute to the ECM aggregation and stiffness of CA.

Objective To explore the feasibility of team-based learning (TBL) for practice teaching of the aerospace nutrition and food hygiene.Methods A total of 90 students were investigated,and were divided into the TBL group (n=46) and the TL group (n=44) by simple random sampling.After the experiment teaching,a test and questionnaire were used to compare the teaching effect of TBL group and TL group.SPSS 18.0 was used for date and the data was analyzed by Independent-Samples t test and Chi-square test.Results Students in TBL group achieved higher mean test scores (85.70 ± 3.47) compared with students (74.10±2.41) in TL group and the difference was statistically significant (t=8.703,P=0.000).The results of the questionnaire showed that,compared with the TL group,TBL group students more agreed with the positive impact of the teaching methods on their team work ability,interpersonal skills,communication ability,problem-solving and self-learning and other aspects,and the differences between two groups were statistically significant (P＜0.05).In addition,the majority of the respondents in TBL group [93.5％ (43/46)] were satisfied with TBL.Conclusions TBL teaching is better than the TL teaching,and it can significantly improve students' comprehension of knowledge and enhance their learning effect.

Hyperbaric oxygen (HBO) medicine is an applied interdiscipline concerning basic me-dicine,clinical medicine,physics and psychology.Indications of HBO treatment involve multiple systems of the body.Based on the practice of almost 30 years,we explore how to adopt heuristic and experiencing style to strengthen the combination of theory and clinical application fortifying practical operation in the teaching. Meanwhile,discussing obstacles in HBO treatment and learning frontiers and progress through literatures or animal experiments can cultivate students' solid theoretical foundation and basic analysis and operation skills,and improve their interest in clinical and scientific research work of hyperbaric oxygen.

Objective To investigate the risk factors contributing to hyperlipidemia and fatty liver in pilots.Methods Two hundred and forty-six pilots received the physical examination and were asked to fill out a questionnaire.Physical examination information included height,weight,abdominal ultrasonography result and blood lipid.The questionnaire included the pilots' age,flying hours time,physical exercise amount,working pressure,sleep condition,optimistic mood status,dietary habits,nutrition knowledge awareness,smoking and drinking habit.According to the results of physical examination,the pilots with hyperlipidemia and(or) fatty liver were selected as case group,and the pilots without hyperlipidemia or fatty liver were in control group.The scores of two groups were compared.According to the caculated BMI,pilots were also divided into normal(BMI 18.5-23.9 kg/m2)overweight(BMI 24 27.9 kg/m2) obesity(BMI＞27.9 kg/m2) groups.The differences on prevalence of hyperlipidemia and fatty liver were compared among different BMI groups.Results ①There were 225 valid questionnaires out of 246 pilots and the valid rate was 91.5％.There were 60 pilots had fatty liver and the prevalence of fatty liver was 26.7％(60/225).There were 42 pilots had hyperlipidemia and the prevalence of hyperlipidemia was 18.7％ (42/225).According to the physical examination,there were 138 pilots in control group and 87 pilots in case group.②In case group,pilots' age,daily cigarette consumption and daily alcohol consumption were higher than those in control group (Z=2.008,2.934,2.153,P＜0.05).The pilots' BMI of case group were higher than that of control group (t=35.793,P＜0.05).The scores of exercise and sleep of case group were lower than those of control group (t=19.518,5.701,P＜0.05).③The detection rates of overweight and obesity in case group were higher than those in control group (x2 =16.327,13.157,P＜0.05).The prevalence differences of hyperlipidemia and fatty liver were statistically significant among different BMI groups (x2 =37.505,P＜0.05).④The smoking and drinking rates of case group were higher than those of control group (x2 =8.636,4.497,P＜0.05).Conclusions The main risk factors of hyperlipidemia and fatty liver in pilots are obesity and lack of exercise.Other factors like age,sleepquality,smoking or drinking habit have certain extent impacts on the diseases.Pilots should strengthen the physical exercise and control BMI to effectively reduce the incidence of hyperlipidemia and fatty liver in order to prolong the pilot's flying career.

Objective To investigate the risk factors contributing to hyperlipidemia and fatty liver in pilots.Methods Two hundred and forty-six pilots received the physical examination and were asked to fill out a questionnaire.Physical examination information included height,weight,abdominal ultrasonography result and blood lipid.The questionnaire included the pilots' age,flying hours time,physical exercise amount,working pressure,sleep condition,optimistic mood status,dietary habits,nutrition knowledge awareness,smoking and drinking habit.According to the results of physical examination,the pilots with hyperlipidemia and(or) fatty liver were selected as case group,and the pilots without hyperlipidemia or fatty liver were in control group.The scores of two groups were compared.According to the caculated BMI,pilots were also divided into normal(BMI 18.5-23.9 kg/m2)overweight(BMI 24 27.9 kg/m2) obesity(BMI＞27.9 kg/m2) groups.The differences on prevalence of hyperlipidemia and fatty liver were compared among different BMI groups.Results ①There were 225 valid questionnaires out of 246 pilots and the valid rate was 91.5％.There were 60 pilots had fatty liver and the prevalence of fatty liver was 26.7％(60/225).There were 42 pilots had hyperlipidemia and the prevalence of hyperlipidemia was 18.7％ (42/225).According to the physical examination,there were 138 pilots in control group and 87 pilots in case group.②In case group,pilots' age,daily cigarette consumption and daily alcohol consumption were higher than those in control group (Z=2.008,2.934,2.153,P＜0.05).The pilots' BMI of case group were higher than that of control group (t=35.793,P＜0.05).The scores of exercise and sleep of case group were lower than those of control group (t=19.518,5.701,P＜0.05).③The detection rates of overweight and obesity in case group were higher than those in control group (x2 =16.327,13.157,P＜0.05).The prevalence differences of hyperlipidemia and fatty liver were statistically significant among different BMI groups (x2 =37.505,P＜0.05).④The smoking and drinking rates of case group were higher than those of control group (x2 =8.636,4.497,P＜0.05).Conclusions The main risk factors of hyperlipidemia and fatty liver in pilots are obesity and lack of exercise.Other factors like age,sleepquality,smoking or drinking habit have certain extent impacts on the diseases.Pilots should strengthen the physical exercise and control BMI to effectively reduce the incidence of hyperlipidemia and fatty liver in order to prolong the pilot's flying career.

Aerospace nutrition and food hygiene is a subject elucidating the effect of aerospace envi-ronment on nutrition and food hygiene which is closely related to health of flight personnel. The teaching work should be in the aim of raising battle effectiveness and enforcing the primary professional capability of students. The most required theory and techniques in both peacetime and wartime was the priority of teach-ing fulfilling mainly through practical or in-site learning. The examination was composed of test paper, ex-periments and health propaganda. The teaching evaluation relied on feed-back of the army on which the teaching plan was revised. Survey in three straight years indicated the exploration enhanced teaching quality significantly.

Objective To compare the subjects' scores of National Aeronautics and Space Administration-task load index (NASA-TLX),the indexes of ECG and performance between the reverse target tracking task and the ordinary target tracking task which simply simulate " reverse operation" of carrier aircraft landing,and to preliminarily investigate the effect of "reverse operation" on pilot's mental workload and its influence factors.Methods Twenty-five young male subjects accomplished the reverse and the ordinary target tracking tasks with two degrees of difficulty.ECG signals were recorded during the resting period before the task,periods of each task and the resting period after the task.Each subjects filled in NASA-TLX scale after the completion of each task and had a score feedback for each task.The scores of NASA-TLX and the indexes of performance were analyzed by analysis of variance (ANOVA) in 2 × 2 factorial design.The indexes of ECG were analyzed by Friedman M test and the multiple comparisons were carried out by LSD-t test.Results The scores of NASA-TLX and the average tracking distance of the reverse target tracking task were higher than those of the ordinary target tracking task (F=21.70,16.14,P＜0.05) and the highest appeared in the reverse dual task (F=6.67,P＜0.05).HR also had the corresponding change (χ2=34.87,P＜0.05),but the indexes of HRV had no significant differences.Conclusions Mental workload of the reverse operation task is higher than that of the ordinary operation task if the other conditions are the same.The reverse operation impacts mental workload severer when more information processing is required.Mental demand,physical demand and frustration level are the major influence factors of causing high mental workload in reverse operations.