To understand current state of physical health levels of first-year students in different body mass index (BMI) categories in Ningxia universities, and to explore the correlation between BMI and physical fitness index (PFI), so as to provide a reference for enhancing physical health levels of university students.

In November 2024, physical fitness test data from 16 631 first-year students across four universities in Yinchuan City, Ningxia from 2019 to 2023 were collected by adopting convenience and stratified cluster random sampling methods. The PFI was calculated using the Z-score of the physical fitness test results, and a nonlinear quadratic model was established via least squares regression to examine the relationship between BMI and PFI among university students.

The BMI for males was (21.69±3.53)kg/m², while for females was (20.78±2.94)kg/m². The composite score for males physical fitness (69.86±9.25) was lower than that for females (72.24±8.15), with a statistically significant difference (t=-17.54, P < 0.01). Moreover, the failure rates of various physical fitness indicators (vital capacity, sit-and-reach, standing long jump, pull-ups/1-minute sit-ups, 1 000 m/800 m run) were higher among males than females (χ²=103.48, 72.45, 14.38, 5 134.85, 188.89, all P < 0.01). Comparisons across BMI categories revealed that among males, the normal weight group outperformed other groups in the 50 m sprint, standing long jump, 1 000 m sprint, composite score, and PFI (F=89.17, 113.90, 179.02, 573.35, 593.08); among female students, the normal weight group outperformed other groups in the 50 m sprint, sit-and-reach, 800 m run, composite score, and PFI (F=10.67, 19.58, 96.45, 294.05, 183.45) (all P < 0.01). The relationship between BMI and PFI among first-year students exhibited a parabolic change trend, students with a moderate BMI demonstrated higher PFI, and as BMI increased, PFI decreased (all P < 0.01).

The physical health level of male students in Ningxia universities is lower than that of female students. There is a correlation between BMI classification and PFI. Tailored intervention measures should be implemented according to the physical characteristics of students across different genders and BMI classifications to enhance university students' physical health.

To investigate the association between 24-hour activity behavior and body composition among primary and secondary school students using compositional data analysis method, so as to provide scientific guidance for optimizing daily activity allocation and improving physical health.

In June 2021, following the principle of random cluster sampling, 349 primary and middle school students were selected by lottery method from Taiyuan City, Shanxi Province. Compositional multiple regression analysis was conducted to examine the relationship between different 24-hour activity behaviors and body composition indicators. The isotemporal substitution model was adopted to examine the quantitative effects of substituting 10 or 20 minutes among activity behaviors on body composition.

In girls, sedentary behavior (SB) time was negatively correlated with fat-free mass (FFM) (β=-4.81); in boys, moderate-to-vigorous physical activity (MVPA) time was positively correlated with FFM (β=7.01), while light physical activity (LPA) time was negatively correlated with FFM (β=-9.26) and positively correlated with body fat percentage (FAT%) (β=0.09) (all P < 0.01). Isocaloric substitution analysis revealed that replacing the same duration of MVPA with SB, sleep (SL), or LPA for 10 or 20 minutes produced significantly greater adverse effects compared to the beneficial effects of MVPA substitution. Replacing MVPA with LPA for 10 minutes resulted in 1.01% increase in FAT% and 0.91% decrease in reverse substitution for boys; replacing MVPA with SB or SL for 10 minutes resulted in a decrease of 1.10 kg and 1.16 kg in FFM for boys, 0.81 kg and 0.74 kg for girls, and reverse substitution increased by 0.92 and 0.97 kg, 0.65 and 0.58 kg, respectively (all P < 0.05). When LPA, SB or SL were replaced with MVPA for 20 minutes, the trend of change were basically consistent (all P < 0.05).

Activity behaviors of 24-hour are associated with body composition among primary and secondary school students. MVPA is the primary influential component.

To understand the epidemiological and etiological characteristics of food poisoning event occurred in a school in Hangzhou, Zhejiang, so as to provide reference for the scientific management of related emergencies.

By determining the nature of the event through epidemiological investigation, a case-control study was carried out to spot suspicious food in May 2024. The hygienic investigation was conducted to find out possible pollution links and factors, patients and canteen practitioners' anal swab, canteen retention samples, catering link daub and other specimens were collected, for rapid pathogen screening. And the suspected pathogen Clostridium perfringens (CP) were isolated and identified according to the screening results, and toxin gene detection and whole genome sequencing and cluster analysis of CP isolated strains were carried out.

The incident resulted in 45 people experiencing gastrointestinal symptoms, such as diarrhea and abdominal pain. The suspicious food was tomato scrambled eggs and corn ribs provided by the student canteen for lunch on May 29. A hygiene investigation found that there was a risk of contamination in the food processing, preparation and storage. A total of 46 anal swabs and 10 canteen retention samples were positive for CP 16 S, 59 strains of CP were isolated from 27 samples, 10 cases and 1 practitioner isolate were positive for CPE (cpe) (F mode), and their whole genome evolution analysis was conducted based on the same source.

The food poisoning event is caused by CP infection carrying CPE (cpe) (F mode), and the possible sources of outbreak are the carriers of the CP by employees. It is recommended that cafeteria staff strengthen training on common foodborne diseases and conduct regular monitoring of pathogens.

To investigate the relationship of metabolic score for insulin resistance (METS-IR) with bone mineral content (BMC) and bone metabolic markers levels among adolescents, so as to provide a scientific foundation for the early identification and prevention of bone-related diseases.

From 2017 to 2019 and 2023, a total of 1 414 adolescents aged 12-18 years from Yinchuan were selected using a method combining convenient sampling with stratified cluster random sampling. The data of basic information, body mass index, BMC, serum osteocalcin (OC), type Ⅰ collagen cross-linked C-terminal peptide (CTX) and calcium (Ca), METS-IR among adolescents were obtained by questionnaire survey, physical measurement and laboratory examination, and METS-IR was divided into four groups Q1-Q4 according to P₂₅, P₅₀ and P₇₅. Logistic regression models combined with restricted cubic splines were employed to analyze the relationship between METS-IR and low BMC as well as low bone metabolic markers. The receiver operating characteristic (ROC) curve was used to evaluate METS-IR effectiveness in diagnosing low BMC.

The levels of BMC, OC, CTX, Ca and METS-IR in the surveyed adolescents were (2.66±0.52)kg, (20.49±13.77)ng/mL, (2 460.89±1 818.96)pg/mL, (2.47±0.67)mmol/L, 30.63±7.58. After adjusting for gender, age and physical activity level, METS-IR in Q4 group had a reduced risk of low BMC and low CTX [OR (95%CI)=0.03(0.01-0.07), 0.45(0.32-0.65)] and an elevated risk of low OC [OR (95%CI)=1.85(1.28-2.67)], compared with the Q1 group (all P < 0.05). Gender-stratified analyses revealed similar trends for both males and females (all P < 0.05). Non-linear dose-response relationships were observed between METS-IR and low BMC (P_{total trend} < 0.01, P_{non-linearity}=0.01), as well as low OC (P_{total trend} < 0.01, P_{non-linearity}=0.01), while a linear relationship was detected with low CTX (P_{total trend} < 0.01, P_{non-linearity}=0.72). ROC curves revealed that METS-IR had the best diagnostic performance for low BMC (AUC=0.85, 95%CI=0.82-0.88, P < 0.01).

Higher METS-IR score is linked to reduced risk of low BMC and CTX but increase risk of low OC among adolescents. These findings suggest METS-IR is a reliable indicator for assessing BMC and early predicting bone health risk among adolescents.

To explore the association between light at night (LAN) of different intensities and ocular biometric parameters among preschool children, so as to provide a reference for optimizing strategies for myopia prevention and control.

From November 2024 to January 2025, a cross-sectional study was conducted among 369 preschool children from one kindergarten in Quanzhou City, Fujian Province. Questionnaire survey and eye examination were performed, and portable light sensors were used to collect LAN exposure data. Spearman correlation analysis was used to examine the associations between the duration of LAN exposure at different intensities and ocular biometric parameters. Generalized linear model was employed to explore the relationships between LAN duration at various intensities and ocular biometric parameters, while restricted cubic spline was used to investigate potential nonlinear associations.

The spherical equivalent (SE), axial length (AL), and axial length/corneal radius of curvature (AL/CR) for preschool children were 0.38 (-0.13, 0.63) diopters, 22.35 (21.86, 22.88) mm, and 2.86 (2.82, 2.90), respectively. The median daily duration (interquartile ranges) of LAN exposure at intensities of 0, >0-100, >100-300, and >300 lx were 6.09(5.31, 6.74), 1.74(1.13, 2.42), 0.06(0.00, 0.26), 0.00(0.00, 0.00)h/d, respectively. The generalized linear model showed that for every additional hour of LAN at >100-300 lx, the AL/CR increased by 0.26 (95%CI=0.01-0.52); for every additional hour of LAN at >300 lx, AL/CR increased by 0.32 (95%CI=0.05-0.59) (both P < 0.05). No statistically significant associations were observed between SE or AL and LAN exposure at any of the intensity levels (0, >0-100, >100-300, and >300 lx) (all P>0.05). The restricted cubic spline model revealed that, except for the nonlinear relationship between LAN duration and AL at >100-300 lx (P=0.02), all other light intensity levels showed linear correlations between LAN duration and preschool children's SE, AL, and AL/CR (both P>0.05). Time-of-day subgroup analysis revealed that during school days, for every additional hour of LAN at >100-300 lx and over 300 lx, AL/CR increased by 0.18 (95%CI=0.01-0.35) and 0.22 (95%CI=0.03-0.41), respectively (both P < 0.05). However, weekend exposure showed no statistically significant association (all P>0.05).

Higher intensity of LAN is associated with increased AL/CR, and reducing exposure to LAN may have a potential protective effect on the visual health of preschool children.