Objective:To investigate the relationship between red blood cell distribution width (RDW) and activity of Crohn′s disease (CD), and explore the diagnostic value of RDW for CD activity.Methods:A cross-sectional study was conducted. Clinical data of CD patients treated continuously at the Sixth Affiliated Hospital of Sun Yat-sen University from November 2012 to October 2014 (CD group) were collected, including the first results of routine hematological examinations and C-reactive protein (CRP) levels after admission. Routine hematological examination results were also collected from healthy peoples undergoing regular health check-ups at the same time, who served as the normal control group. CD patients were divided into remission, mild activity, and moderate-severe activity groups based on the Crohn′s disease activity index (CDAI). The levels of routine hematological indicators including RDW and platelet-to-lymphocyte ratio (PLR) were compared between the CD group and the normal control group, as well as among different subgroups of CD patients. The correlations between RDW, PLR and CD activity or CRP were analyzed, and the diagnostic value of RDW for CD activity was evaluated by using ROC curve. Logistic univariate and multivariate regressions were performed to analyze the influencing factors of the activity of CD. Logistic regression equation was constructed to calculate the diagnostic efficacy of the influencing factors.Results:A total of 303 CD patients (216 males, 87 females; mean age 28.6 ± 11.7 years) were assigned to CD group and 293 healthy peoples (190 males, 103 females; mean age 30.1 ± 12.3 years) were assigned to normal control group. There was no significant differences in age and gender between the two groups (both P>0.05), indicating comparability. Among the CD patients, 109 were in remission group, 106 in mild activity group, and 88 in moderate-severe activity group. There was no significant differences in age and gender among the three subgroups (all P>0.05), indicating comparability. Compared with the normal control group, RDW (15.26% ± 2.51% vs. 13.10% ± 1.13%, P<0.001), PLR (245.09 ± 158.69 vs. 119.07 ± 36.52, P<0.001), neutrophil-to-lymphocyte ratio (NLR) [3.22 (2.06, 4.75) vs. 1.76 (1.39, 2.32), P<0.001], white blood cell count [ (7.68 ± 3.30) ×10 9/L vs. (6.52 ± 1.68) × 10 9/L, P<0.001] and platelet count [ (320.69 ± 116.10) × 10 12/L vs. (230.10 ± 51.08) × 10 12/L, P<0.001] were significantly higher in the CD group, while hemoglobin [ (112.8 ± 21.0) g/L vs. (137.1 ± 13.5) g/L, P<0.001] and platelet distribution width (PDW) [ (10.70 ± 1.91) fl vs. (11.89 ± 1.75) fl, P<0.001] were significantly lower. Compared with patients in remission group, the patients in mild activity group had higher RDW and platelet count, and lower hemoglobin (all P<0.05). Compared with the patients in remission and mild activity groups, the patients in moderate-severe activity group had higher RDW, PLR and NLR, and lower hemoglobin (all P<0.05). Correlation analysis showed the positive correlations between RDW, PLR and CD activity ( r = 0.423, P<0.001; r = 0.295, P<0.001), and RDW was positively correlated with CRP ( r = 0.438, P<0.001). The cut-off value of RDW for predicting CD activity was 13.85%, while the area under curve (AUC) was 0.723 (95% CI: 0.664-0.782, P<0.001), sensitivity was 0.784 and specificity was 0.550. Logistic multivariable regression analysis showed that RDW ( OR = 1.532, 95% CI: 1.291-1.818, P<0.001) and PLR ( OR = 1.003, 95% CI: 1.001-1.006, P = 0.013) were independent risk factors. The combination of RDW and PLR in diagnosing CD activity yielded an AUC of 0.730 (95% CI: 0.673-0.787, P<0.001), sensitivity of 0.407, and specificity of 0.927. Conclusions:CD patients with high RDW have more severe activity. RDW is a simple and practical indicator for diagnosing the activity of CD.

Objective:To compare and analyze the differences of exercise cardiopulmonary function and the correlation of different cardiopulmonary function indexes among different aircraft types in pilots.Methods:Retrospective study was used. The exercise cardiopulmonary function of 68 Air Force pilots who were qualified for flight in aeromedical identification were tested with the Italian Cosmed exercise cardiopulmonary function tester at a power increasing rate of 25 W/min. The subjects were divided into fighter group and other aircraft group according to aircraft types. The differences of exercise cardiopulmonary function between 2 groups were compared. The correlation between maximal oxygen uptake and age, body mass index, and the correlation between heart rate recovery and exercise endurance were analyzed.Results:There were significant differences in maximal heart rate, respiratory quotient and heart rate recovery value at 1 min after exercise between fighter group (32 cases) and other aircraft group (36 cases) ( t=2.28, 2.50, 2.37, P=0.026, 0.049, 0.021). There was no significant difference in other indexes. The maximal oxygen uptake was negatively correlated with age and body mass index ( r=-0.329, -0.339, both P<0.001). The values of heart rate recovery at 2 min and 3 min after exercise were positively correlated with maximal oxygen uptake and maximal exercise power ( r=0.284, 0.290, 0.306, 0.268, P=0.001, 0.026, 0.002, 0.002). Conclusions:The indexes of exercise cardiopulmonary function have significant differences among pilots in different aircraft types, and there are significant changes with age and weight gain. The heart rate after exercise can monitor the changes of cardiopulmonary function under different training conditions.

Objective:To investigate the relationship between red blood cell distribution width (RDW) and activity of Crohn′s disease (CD), and explore the diagnostic value of RDW for CD activity.Methods:A cross-sectional study was conducted. Clinical data of CD patients treated continuously at the Sixth Affiliated Hospital of Sun Yat-sen University from November 2012 to October 2014 (CD group) were collected, including the first results of routine hematological examinations and C-reactive protein (CRP) levels after admission. Routine hematological examination results were also collected from healthy peoples undergoing regular health check-ups at the same time, who served as the normal control group. CD patients were divided into remission, mild activity, and moderate-severe activity groups based on the Crohn′s disease activity index (CDAI). The levels of routine hematological indicators including RDW and platelet-to-lymphocyte ratio (PLR) were compared between the CD group and the normal control group, as well as among different subgroups of CD patients. The correlations between RDW, PLR and CD activity or CRP were analyzed, and the diagnostic value of RDW for CD activity was evaluated by using ROC curve. Logistic univariate and multivariate regressions were performed to analyze the influencing factors of the activity of CD. Logistic regression equation was constructed to calculate the diagnostic efficacy of the influencing factors.Results:A total of 303 CD patients (216 males, 87 females; mean age 28.6 ± 11.7 years) were assigned to CD group and 293 healthy peoples (190 males, 103 females; mean age 30.1 ± 12.3 years) were assigned to normal control group. There was no significant differences in age and gender between the two groups (both P>0.05), indicating comparability. Among the CD patients, 109 were in remission group, 106 in mild activity group, and 88 in moderate-severe activity group. There was no significant differences in age and gender among the three subgroups (all P>0.05), indicating comparability. Compared with the normal control group, RDW (15.26% ± 2.51% vs. 13.10% ± 1.13%, P<0.001), PLR (245.09 ± 158.69 vs. 119.07 ± 36.52, P<0.001), neutrophil-to-lymphocyte ratio (NLR) [3.22 (2.06, 4.75) vs. 1.76 (1.39, 2.32), P<0.001], white blood cell count [ (7.68 ± 3.30) ×10 9/L vs. (6.52 ± 1.68) × 10 9/L, P<0.001] and platelet count [ (320.69 ± 116.10) × 10 12/L vs. (230.10 ± 51.08) × 10 12/L, P<0.001] were significantly higher in the CD group, while hemoglobin [ (112.8 ± 21.0) g/L vs. (137.1 ± 13.5) g/L, P<0.001] and platelet distribution width (PDW) [ (10.70 ± 1.91) fl vs. (11.89 ± 1.75) fl, P<0.001] were significantly lower. Compared with patients in remission group, the patients in mild activity group had higher RDW and platelet count, and lower hemoglobin (all P<0.05). Compared with the patients in remission and mild activity groups, the patients in moderate-severe activity group had higher RDW, PLR and NLR, and lower hemoglobin (all P<0.05). Correlation analysis showed the positive correlations between RDW, PLR and CD activity ( r = 0.423, P<0.001; r = 0.295, P<0.001), and RDW was positively correlated with CRP ( r = 0.438, P<0.001). The cut-off value of RDW for predicting CD activity was 13.85%, while the area under curve (AUC) was 0.723 (95% CI: 0.664-0.782, P<0.001), sensitivity was 0.784 and specificity was 0.550. Logistic multivariable regression analysis showed that RDW ( OR = 1.532, 95% CI: 1.291-1.818, P<0.001) and PLR ( OR = 1.003, 95% CI: 1.001-1.006, P = 0.013) were independent risk factors. The combination of RDW and PLR in diagnosing CD activity yielded an AUC of 0.730 (95% CI: 0.673-0.787, P<0.001), sensitivity of 0.407, and specificity of 0.927. Conclusions:CD patients with high RDW have more severe activity. RDW is a simple and practical indicator for diagnosing the activity of CD.

Objective:To compare and analyze the differences of exercise cardiopulmonary function and the correlation of different cardiopulmonary function indexes among different aircraft types in pilots.Methods:Retrospective study was used. The exercise cardiopulmonary function of 68 Air Force pilots who were qualified for flight in aeromedical identification were tested with the Italian Cosmed exercise cardiopulmonary function tester at a power increasing rate of 25 W/min. The subjects were divided into fighter group and other aircraft group according to aircraft types. The differences of exercise cardiopulmonary function between 2 groups were compared. The correlation between maximal oxygen uptake and age, body mass index, and the correlation between heart rate recovery and exercise endurance were analyzed.Results:There were significant differences in maximal heart rate, respiratory quotient and heart rate recovery value at 1 min after exercise between fighter group (32 cases) and other aircraft group (36 cases) ( t=2.28, 2.50, 2.37, P=0.026, 0.049, 0.021). There was no significant difference in other indexes. The maximal oxygen uptake was negatively correlated with age and body mass index ( r=-0.329, -0.339, both P<0.001). The values of heart rate recovery at 2 min and 3 min after exercise were positively correlated with maximal oxygen uptake and maximal exercise power ( r=0.284, 0.290, 0.306, 0.268, P=0.001, 0.026, 0.002, 0.002). Conclusions:The indexes of exercise cardiopulmonary function have significant differences among pilots in different aircraft types, and there are significant changes with age and weight gain. The heart rate after exercise can monitor the changes of cardiopulmonary function under different training conditions.

Objective:To explore the quantitative effect of smoking on pilots′ physical fitness.Methods:According to smoking index, 215 fighter pilots were chosen as subjects and divided into non-smoking group (143 cases), low smoking-index group (23 cases), moderate smoking-index group (20 cases) and high smoking-index group (29 cases). Subjects were asked to rest on the power bicycle for 3 min, then start warm up at a speed of 60 r/min (no-load, low-level exercise at 60 r/min) for 3 min, and then execute continuously exercise at a constant speed with a power increase of 25 W/min. The load exercise was stopped immediately when the maximum exercise level was reached. Age and body mass index (BMI) were recorded, and cardiopulmonary function indexes such as exercise time, exercise power and respiratory exchange rate (RER) were measured.Results:There was no significant difference on age, BMI and RER among the 4 groups ( P>0.05), but there were significant differences in exercise time and exercise power ( F=6.02, 6.25, P=0.001, P<0.001). Under the condition of the same RER, the exercise time and exercise power of the moderate and high smoking-index group (472.1±54.6 s, 456.9±60.4 s and 197.2±23.1 W, 190.2±24.4 W) were significantly less than those of the non-smoking group (506.3±65.5 s and 211.1±26.9 W) ( P<0.05). Conclusions:This study showed that the exercise time and exercise power of moderate and high smoking-index pilots in increasing power bicycles were significantly lower than those of non-smoking pilots. If the pilots were with moderate-high smoking index their cardiopulmonary function would be affected.

Objective:To explore the relationship between neck muscle strength and elastic strain of flying personnel by comparing the changes of neck muscle elastic strain values and neck muscle strength before and after neck muscle training in flying personnel with neck pain.Methods:By using CME-1 neck muscle strength trainer, 56 flying personnel were trained under isometric and changeable velocity and resistant (CVR) training mode for 2 weeks. The neck muscle strength and neck muscle elastic strain values before and after training were compared.Results:The elastic strain values of longus colli, splenius capitis and levator scapula were significantly increased by neck muscle training ( t=4.154, 2.348, 2.745, P<0.001, P=0.040, 0.006). The relative growth rate of the average elastic strain values of longus colli, splenius capitis and levator scapula after training was 13.75%, 4.18% and 2.8%, respectively. After neck muscle training, the average maximum neck muscle strength and average 10 s maximum impulse in the directions of forward flexion, backward extension, left flexion and right flexion were higher than those before training, and the difference was statistically significant ( t=3.364-8.284, all P<0.01); The relative growth rate of the average maximum neck muscle strength in each direction was 39.3%, 34.6%, 35.2% and 28.4%, respectively, and the relative growth rate of the average 10 s maximum impulse was 51.4%, 33.6%, 42.7% and 34.5%, respectively. The elastic strain values of levator scapula and longus colli were negatively correlated with the average maximum muscle strength of anterior flexor ( r=-0.281, -0.387, P=0.036, 0.004). Conclusions:Neck muscle training can effectively improve the strength of neck muscle groups and the elastic strain of some muscle groups. The elastic strain values of levator scapula and longus colli are negatively correlated with the average maximum muscle strength of anterior flexor, those suggesting that neck muscle training has a certain effect on enhancing the activity of anterior flexor muscle groups and maintaining the physiological lordosis of cervical spine.

Objective:To explore the quantitative effect of smoking on pilots′ physical fitness.Methods:According to smoking index, 215 fighter pilots were chosen as subjects and divided into non-smoking group (143 cases), low smoking-index group (23 cases), moderate smoking-index group (20 cases) and high smoking-index group (29 cases). Subjects were asked to rest on the power bicycle for 3 min, then start warm up at a speed of 60 r/min (no-load, low-level exercise at 60 r/min) for 3 min, and then execute continuously exercise at a constant speed with a power increase of 25 W/min. The load exercise was stopped immediately when the maximum exercise level was reached. Age and body mass index (BMI) were recorded, and cardiopulmonary function indexes such as exercise time, exercise power and respiratory exchange rate (RER) were measured.Results:There was no significant difference on age, BMI and RER among the 4 groups ( P>0.05), but there were significant differences in exercise time and exercise power ( F=6.02, 6.25, P=0.001, P<0.001). Under the condition of the same RER, the exercise time and exercise power of the moderate and high smoking-index group (472.1±54.6 s, 456.9±60.4 s and 197.2±23.1 W, 190.2±24.4 W) were significantly less than those of the non-smoking group (506.3±65.5 s and 211.1±26.9 W) ( P<0.05). Conclusions:This study showed that the exercise time and exercise power of moderate and high smoking-index pilots in increasing power bicycles were significantly lower than those of non-smoking pilots. If the pilots were with moderate-high smoking index their cardiopulmonary function would be affected.

Objective:To explore the relationship between neck muscle strength and elastic strain of flying personnel by comparing the changes of neck muscle elastic strain values and neck muscle strength before and after neck muscle training in flying personnel with neck pain.Methods:By using CME-1 neck muscle strength trainer, 56 flying personnel were trained under isometric and changeable velocity and resistant (CVR) training mode for 2 weeks. The neck muscle strength and neck muscle elastic strain values before and after training were compared.Results:The elastic strain values of longus colli, splenius capitis and levator scapula were significantly increased by neck muscle training ( t=4.154, 2.348, 2.745, P<0.001, P=0.040, 0.006). The relative growth rate of the average elastic strain values of longus colli, splenius capitis and levator scapula after training was 13.75%, 4.18% and 2.8%, respectively. After neck muscle training, the average maximum neck muscle strength and average 10 s maximum impulse in the directions of forward flexion, backward extension, left flexion and right flexion were higher than those before training, and the difference was statistically significant ( t=3.364-8.284, all P<0.01); The relative growth rate of the average maximum neck muscle strength in each direction was 39.3%, 34.6%, 35.2% and 28.4%, respectively, and the relative growth rate of the average 10 s maximum impulse was 51.4%, 33.6%, 42.7% and 34.5%, respectively. The elastic strain values of levator scapula and longus colli were negatively correlated with the average maximum muscle strength of anterior flexor ( r=-0.281, -0.387, P=0.036, 0.004). Conclusions:Neck muscle training can effectively improve the strength of neck muscle groups and the elastic strain of some muscle groups. The elastic strain values of levator scapula and longus colli are negatively correlated with the average maximum muscle strength of anterior flexor, those suggesting that neck muscle training has a certain effect on enhancing the activity of anterior flexor muscle groups and maintaining the physiological lordosis of cervical spine.

Objective:To introduce the formulation and implementation of exercise prescription for military flying personnel.Literature resource and selection:The related literature on exercise prescription of military flying personnel published at home and abroad.Literature quotation:Fifty-eight references were cited, including 46 articles, 6 reviews, 5 dissertations and 1 conference paper.Literature synthesis:Exercise prescription plays an important role in improving the physical function, physical quality, psychological stress and flight ability of flying personnel. The formulation of exercise prescription for flying personnel needs to focus on such aspects as anti-acceleration endurance, muscle strength, exercise ability and cardiopulmonary exercise function. This paper analyzes the elements of exercise prescription for flying personnel, including the selection of exercise type, the control of exercise intensity, the arrangement of exercise time and the setting of exercise frequency.Conclusions:Under the mode of flying personnel′s robust promotion and support, the formulation of individualized moderate intensity exercise prescription according to different types of aircraft, models of aircraft, types of personnel, ages and physical and mental conditions can help flying personnel to improve the physical and mental health and military operation ability.

Objective:To introduce the formulation and implementation of exercise prescription for military flying personnel.Literature resource and selection:The related literature on exercise prescription of military flying personnel published at home and abroad.Literature quotation:Fifty-eight references were cited, including 46 articles, 6 reviews, 5 dissertations and 1 conference paper.Literature synthesis:Exercise prescription plays an important role in improving the physical function, physical quality, psychological stress and flight ability of flying personnel. The formulation of exercise prescription for flying personnel needs to focus on such aspects as anti-acceleration endurance, muscle strength, exercise ability and cardiopulmonary exercise function. This paper analyzes the elements of exercise prescription for flying personnel, including the selection of exercise type, the control of exercise intensity, the arrangement of exercise time and the setting of exercise frequency.Conclusions:Under the mode of flying personnel′s robust promotion and support, the formulation of individualized moderate intensity exercise prescription according to different types of aircraft, models of aircraft, types of personnel, ages and physical and mental conditions can help flying personnel to improve the physical and mental health and military operation ability.