Objective: To explore the relationship between physical activity, screen time, sleep duration and physical health of middle school students, to provide reference for physical health intervention in middle school students. Methods: A total of 1 614 students from 12 middle schools in Tianjin were investigated by stratified random cluster sampling. According to the "Canadian 24 Hour Movement Guidelines for Children and Youth", participants were divided into 4 groups: "full qualified group", "2 item qualified group", "1 item qualified group" and "unqualified group". Binary Logistic regression analysis was used to predict physical health risk. Results: Only 5.2% boys and 4.2% girls met the standard in all three behaviors, and 16.4% boys and 16.3% girls failed to meet the standard in all three behaviors. The excellent and good rates were 77.7% and 71.8% in the 2 item qualified group and the full qualified group, respectively. The physical health risk of middle school students with insufficient physical activity was 1.76 times higher than that of those who achieved the standard, and the physical health risk of students with too much screen time was 1.34 times higher than that of those who achieved the standard. Physical health risk of middle school students with insufficient sleep duration was 2.86 times higher than that of those who achieved the standard, and the risk of overweight and obesity was 1.49 times higher than that of those who achieved the standard ( P <0.05). Compared with the middle school students who achieved all the standards, physical health risk of unqualified group was 3.63 times, and that of the 1 item qualified group was 2.10 times ( P < 0.01 ). Conclusion Middle school students meet two or more recommendations in physical activity, screen time and sleep duration are more likely to have better physical health and lower risk of overweight and obesity. The findings suggest that students should engage in active sports to increase the high intensity of physical activity, reduce screen time, maintain a healthy sleep habits, in order to obtain better health level.

Objective To investigate the effects of sevoflurane exposure on the hypothalamic-pituitary-adrenal (HPA)axis development in neonatal rats.Methods Fifty-four SD rats (P6)were randomly divided into three groups:control group (group C),sevoflurane group (group S)and bu-metanide+sevoflurane group (group BS),n = 18 in each group.In group C,rats were treated with pure oxygen for 6 hours and rats in group S received 2.1% sevoflurane anesthesia for 6 h.Rats in group BS also received 2.1% sevoflurane anesthesia for 6 h,but they were injected with bumetanide before 30 min and at 3 h during the anesthesia.6 rats from each group were randomly selected and the tail blood was collected to measure the corticosterone in the serum using ELISA.Remaining rats in each group were normally housed to P60.A elevated plus maze (EPM)were employed to investigate the anxiety-like behavior,and restraint stress were used to evaluate the function of HPA axis. Results In P6 rats,sevoflurane significantly increased the serum corticosterone level (P < 0.01 ) while bumetanide pretreatment decreased corticosterone level (P <0.01).In P60 rats,neonatal expo-sure to sevoflurane decreased the visits and time spent in the open arms of EPM (P < 0.05 ),in-creased the corticosterone level pre-stress and post-stress (P <0.05 or P < 0.01 ).Pretreatment of bumetanide normalized serum corticosterone level and the anxiety behavior in the EPM. Conclusion Neonatal sevoflurane exposure caused hyperactive HPA axis in rats,which is normalized by bumetanide pretreatment through blocking GABAA receptors.

Objective To compare the diagnostic yield of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) for solid pancreatic masses performed with three different needle types through the cytological results.Methods All patients with solid pancreatic masses larger than 2cm from December 2010 to May 2011 were enrolled,and divided into two groups according to different access of EUS-FNA,trans-gastric approach with 19-,22-and 25-gauge needles (n =42) and trans-duodenal approach with 22-and 25-gauge needles (n =10).In both groups,EUS-FNA was performed with randomization of needle types.During the puncture,the suction,the number of movements,and the depth of insertion were fixed.At the end of the puncture,a liquid-based cytological (LBC) preparation was used to fix the specimen.One cytopathologists was assigned to make the diagnosis and comparison.Results Technical success was 100％ and no procedure related complications occurred.No statistically significant differences were observed in different needles in terms of all cytological parameters between two groups (P ＞ 0.05).However,the 25-gauge needle showed a trend towards a higher sensitivity,specificity,positive predictive value,negative predictive value and accuracy.Conclusion There is no significant difference in yield of cytological results between different needle types,although 25-gauge needle shows a relative superiority.

Abstract Cardiopulmonary endurance is an important indicator of the physical health of children and adolescents. The 6 Minute Walk Test(6MWT) is an emerging method used to assess the cardiorespiratory endurance of children and adolescents, and has been applied in many countries and regions. This study aims to review the application of 6MWT in the assessment of cardiopulmonary endurance in children and adolescents, analyze the application prospects and precautions of 6MWT, and provide references for the application and promotion of 6MWT in the assessment of cardiopulmonary endurance in children and adolescents, as well as the formulation of related evaluation standards.

Objective: An isochronous substitution model was established to explore the association and substitution effect between college students 24 hour activity behavior and physical health, so as to provide specific activity behavior suggestions for college students to improve their physical health. Methods: A stratified random cluster sampling method was used to conduct physical fitness tests and 24 hour activity behavior surveys among 2 794 college students in 12 colleges and universities in Tianjin.Time spent on sedentary behavior(SB), light intensity physical activity(LPA), moderate to vigorous physical activity(MVPA) and sleep(SLP) time. The isochronous method of components was used to explore the relationship between 24 h activity behavior and physical health. Results: Except for 50 m running, MVPA was negatively correlated with BMI Z ( β =-0.62, P <0.05), but positively correlated with other physical fitness indexes ( β =0.34~274.23, P <0.05). LPA was not associated with lung capacity, sitting forward flexion and 50 m running, and negatively correlated with other physical fitness indexes ( β =-14.30- -0.19, P <0.05). SB was negatively correlated with most physical fitness indexes ( β =-11.57- -0.33, P <0.05), but positively correlated with BMI Z ( β =0.45, P < 0.05 ). In addition to lung capacity, SLP was positively correlated with BMI Z , total physical fitness score,1 minute sit-ups, pull ups, 800/1 000 m running, sitting forward flexion, and 50 m running ( β =0.27-11.21, P <0.05), but negatively correlated with long jump ( β =-0.10, P <0.05）. Isochronous substitution showed that the adverse effects of 30 min/d SB and LPA substitution of MVPA were much greater than the beneficial effects of MVPA substitution for corresponding behaviors (total physical score: SB, -0.58 vs 0.47 points; LPA, -0.50 vs 0.38 points). Conclusion MVPA and SLP have been found to have a positive effect on physical fitness among college students. Therefore, in the process of improving the physical health of college students, ensuring adequate sleep, improving MVPA and reducing SB as much as possible may be one of the effective methods.

Objective: To explore the relationship between isochronous substitution and BMI, waist circumference (WC), and body fat rate (FAT) among physical activity (PA), sedentary (SB), and sleep (SLP), so as to provide effective measures for obesity control in adolescents. Methods: A total of 193 adolescents aged 12-15 (90 males and 103 females) was randomly selected, and their height, weight, and BMI were measured using routine testing methods from May to August 2022. The PA, SB and SLP of the participants were measured using a 3D accelerometer (ActiGraph GT3X+). Results: The arithmetic mean value overestimated SLP (40.8%) and SB (39.6%) to some extent, and underestimated LPA (16.1%) and MVPA (3.5%) to some extent. Based on the ISM at 15 min, MVPA was substituted for other activity, BMI Z decreased by 0.17-0.22 units, WC Z decreased by 0.16-0.20 units, and FAT Z decreased by 0.17-0.22 units. The substitution between MVPA and for other activity exhibited significant asymmetry. The effects of MVPA substitutions for SB was the largest, followed by the effects of MVPA substitutions for SLP, and the effects of MVPA substitutions for LPA was the lowest. As MVPA substitutions for other behaviors, it reached its maximum (0.06-0.08 units ) when the MVPA time increased by 5 minutes. Conclusions MVPA plays an irreplaceable role in the control of adolescent obesity . While reducing SB time, MVPA duration should be increased to ensure that the daily MVPA duration is not less than 55 minutes in order to effectively control obesity.

BACKGROUND:Sarcopenia refers to age-related progressive,systemic muscle mass reduction and/or muscle strength decline or muscle physiological function decline,which is related to the occurrence of a variety of adverse outcomes in older adults.Exercise is considered to be one of the main strategies for combating sarcopenia in older adults,but there is a lack of specific intervention methods of different exercise patterns to intervene in sarcopenia. OBJECTIVE:To elaborate the main influencing factors of sarcopenia and the research progress of different exercise methods to improve sarcopenia in older adults,providing reference and basis for combating sarcopenia in older adults. METHODS:Web of Science,PubMed,CNKI,VIP,WanFang databases were retrieved for relevant literature published from January 2000 to October 2023 using the keywords of"sarcopenia,sport,exercise intervention,resistant training,aerobic exercise,whole body vibration training,mixed training,physical performance,muscle strength,muscle mass"in Chinese and English,respectively.A total of 126 articles were included for review. RESULTS AND CONCLUSION:Resistance exercise is still the most effective way to prevent and treat senile sarcopenia,and the effect of high-intensity resistance exercise is more significant.However,in practical application,we should pay attention to the gradual increase of training load intensity.Aerobic exercise combined with resistance exercise is more effective to improve muscle mass and function in the elderly than a single exercise mode.It is suggested that older adults can carry out the transition of low-intensity aerobic exercise in the early stage and increase resistance exercise individually in the late stage.Whole body vibration training is a new treatment method for the prevention and treatment of senile sarcopenia,but particular attention should be paid to the effects of frequency,amplitude,and duration on patients during practical application.Multicomponent exercise combines different exercise modes,which can give full play to their respective advantages,so as to personalize exercise interventions.

Objective:To measure the anatomical parameters of the simulated low tibial tunnel of posterior cruciate ligament (PCL) based on knee CT images so as to provide clinical reference for accurate location of the tunnel.Methods:The CT images of 201 healthy knee joints collected at Department of Orthopedics, The Second Hospital of Lanzhou University from June 2016 to September 2021 were used for simulation of the PCL low tibial tunnel. The anatomical parameters of the tibial tunnel were measured using the RadiAnt DICOM Viewer. The primary measures included the angle between tibial plateau and tibial tunnel (ATPT) and the perpendicular distances from the tibial tunnel entrance and exit point to the tibial plateau (L1 and L2). The secondary measures included the angle between tibial plateau and posterior slope (PSA), the angle between tibial anatomical axis and central line of tibial tunnel (ATAA), the angle between posterior tibial slope line and the central line of tibial tunnel (APST), the anterior and posterior diameter of tibial plateau (APD), the length of posterior tibial slope (LPTS), and the length of tibial tunnel (LTT). The measurement results were analyzed according to the body height (divided into 3 groups: a 1.00 to 1.60 m group, a 1.61 to 1.70 m group, and a ≥1.71 m group) and gender using the software IBM SPSS 26.Results:The primary measures: ATPT was 37.0°±4.5°, and L1 and L2 were respectively (57.8±7.4) mm and (34.5±3.3) mm. The secondary measures: PSA 128.1°±5.4°, ATAA 52.7°±4.1°, APST 89.1°±5.9°, APD was (32.9±2.6) mm, LPTS (20.5±2.4) mm, and LTT (40.9±5.7) mm. After grouping by gender, there was no significant difference in PSA between men and women ( P>0.05) while there were significant differences in the other indexes between men and women ( P<0.05). After grouping by body height, there was no significant difference in ATPT, PSA, APST or ATAA between the 3 groups (1.00 to 1.60 m group, 1.61 to 1.70 m group and ≥1.71 m group) ( P>0.05) while there were significant differences in L1, L2, APD, LPTS and LTT between the 3 groups ( P<0.05). Conclusions:Based on the knee CT images, the primary measures of PCL low tibial tunnel are as follows: the angle between tibial plateau and tibial tunnel is 37.0°±4.5°, and the perpendicular distances from the tibial tunnel entrance and exit point to the tibial plateau are (57.8±7.4) mm and (34.5±3.3) mm, respectively. Gender and body height are the important factors influencing the above measurement outcomes.