Objective: To understand the association between weight-adjusted-waist index (WWI) and cardiopulmonary endurance among middle school students, so as to provide references for the improvement of cardiopulmonary endurance levels in adolescents. Methods: From June 2015 to December 2018 by using the method of purposive sampling, height, weight, waist circumference, and 20 m shuttle-run tests were measured among 44 870 adolescents aged 13-18 from Northeast, North, East, South, Southwest and Northwest of China. The WWI of the adolescents and the maximum oxygen uptake (VO 2max ) were calculated indirectly. The t-test and one way analysis of variance were used for comparison, and the curve regression analysis method was adopted to analyze the relationship between WWI and VO 2max . Results: For Chinese middle school students aged 13-18, the WWI was (9.35±1.02), the number of 20 m shuttle-run was (38.89±18.14) times, and VO 2max was (39.96±5.88) mL/(kg ·min -1 ). The differences of VO 2max between WWI quartile arrays of boys aged 13-18 were statistically significant ( F=15.19, 9.00, 14.97, 20.48, 28.13, 10.13 , P <0.01), girls had the same trend ( F=23.36, 16.61, 33.45, 32.96, 18.23, 19.36, P <0.01). There was an inverted U shaped curve relationship between WWI and cardiopulmonary endurance. When WWI was 8.5, the VO 2max level reached the highest, which was 40.07 mL/(kg ·min -1 ). Compared with girls, WWI in boys had a more significant impact on cardiopulmonary endurance. Conclusion Maintaining optimal WWI levels may enhance adolescents cardiopulmonary endurance.

Objective:To analyze the causal relationship between gut microbiota and gestational diabetes,and to clarify its mechanism.Methods:Two-sample Mendelian randomization(MR)analysis was conducted by using summary data from genome-wide association study(GWAS)for gut microbiota and gestational diabetes.The GWAS data of gut microbiota were obtained from a GWAS study from the MiBioGen consortium;the GWAS data on gestational diabetes were sourced from the FinnGen consortium's publicly available R8 dataset;inverse variance weighted(IVW)method was used as the primary method to detect the causal association between the gut microbiota and the gestational diabetes.Sensitivity analysis was performed by Weighted Median and MR Egger methods;heterogeneity and pleiotropy were detected by Cochran's Q,MR-PRESSO,Egger intercept tests and Leave-One-Out analysis;multivariable MR was used to adjust for the effect of body mass index(BMI);reverse MR was used to explore the presence of reverse causal associations;Gene Ontology(GO)fuctional and Kyoto Encyclopedia of Genes and Genomes(KEGG)signaling enrichment analyses were used to explore the potential pathways through which gut microbiota may have impact on gestational diabetes.Results:Four gut microbes were found to be causally associated with gestational diabetes:the genus Methanobrevibacter and the phylum Euryarchaeota displayed negative causal relationships with the risk of gestational diabetes,while the genus Olsenella and genus Lachnoclostridium exhibited positive causal associations.No significant heterogeneity or horizontal pleiotropy was detected in the analysis.The reverse MR analysis did not reveal any causal relationship.After adjusting for BMI,the multivariable MR analysis results showed there were the causal associations between the genus Olsenella and the phylum Euryarchaeota with the risk of gestational diabetes.The GO fuctional and KEGG signaling pathway enrichment analyses results showed that axon development,axon production,insulin secretion and other pathways were significantly enriched.Conclusion:There are causal associations between four gut microbes and gestational diabetes.Among them,the significant correlations with gestational diabetes are still observed in phylum Euryarchaeota and genus Olsenella after adjusting for BMI.

Objective:To compile the "Quick Psychological Assessment Scale for Military Training Injuries", analyze the psychological status and influencing factors of the wounded during military training, and propose intervention measures.Methods:Totally 105 wounded patients during military training who were treated in the Orthopedic Center at the Eighth Medical Center of Chinese PLA General Hospital from December 2018 to October 2019 were selected. The self-designed "Quick Psychological Assessment Scale for Military Training Injuries" was used to assess the anxiety and depression of the wounded 1-10 d post injury. The age, rank, injured part, injury type, interval from injury to surgical treatment, nature of the task performed, Barthel index, and the effects of Perceived Social Support Scale (PSSS) on the anxiety and depression of the wounded were observed, and CHISS2011 was used for statistical analysis.Results:The expert validity of the "Quick Psychological Assessment Scale for Military Training Injuries" was 0.893. The Cronbach's α coefficient, validity and norm of the rapid anxiety assessment scale was 0.754, 0.997 and (10.54±2.80) , respectively; the Cronbach's α coefficient, validity and norm of the rapid depression scale was 0.749, 0.997 and (11.60±3.22) , respectively. On the seventh day after injury, the rapid anxiety score of the wounded was (13.70±3.12) , which was statistically significantly different from the norm ( t=-10.588, P< 0.01) ; the rapid depression score was (11.83±2.99) , which was not statistically significantly different from the norm ( t=0.687, P> 0.05) . Cox regression analysis revealed that the interval from injury to surgical treatment, PSSS score and Barthel index were correlated with the anxiety of the wounded during military training ( P< 0.05) ; the nature of the tasks performed and the time of receiving surgical treatment were correlated with the depression after injury during military training ( P< 0.05) . Conclusions:The "Quick Psychological Assessment Scale for Military Training Injuries" has good performance. Mild and moderate anxiety is the focus of psychological intervention for the wounded during military training. Early implementation of effective treatment, recovery of self-care ability as soon as possible and effective social support can improve the mental state of the wounded during military training.