Objective: To analyze the relationship of gross motor skills and perceptual motor abilities with physical activity levels in preschool children in a Beijing kindergarten, so as to provide a reference for promoting the development of motor competence. Methods: From September 2018 to March 2021, preschoolers aged 4-5 years were selected using convenience sampling method from an urban kindergarten in Beijing. The Test of Gross Motor Development-Third Version(TGMD-3) was used to assess basic preschoolers s gross motor skills ( n =152). The Pictorial Scale of Perceived Movement Skill Competence(PMSC) was used to evaluate perceptual motor skills ( n =151). Accelerometers (Actigraph GT3X) were used to record physical activity levels ( n =52). Data were analyzed using one way analysis of variance (ANOVA) and Pearson correlation coefficients. Results: The mean scores for gross motor skills and perceptual motor abilities were (38.76±13.48) and (35.49±6.50), respectively. The moderate to vigorous physical activity(MVPA) level was(52.60±27.44) minutes per day. No statistically significant correlations were found between gross motor skills, perceptual motor abilities MVPA among boys, girls or the overall group ( r =-0.20 to 0.25, all P >0.05). However, Boys locomotor skills, overall children s locomotor skills, and boys gross motor skills were all positively correlated with MVPA( r =0.34-0.45, all P <0.05). Conclusion There is a correlation between locomotor skills and physical activity levels in 4 to 5-year-old children.

Objective:To study the effect of different doses of 60Co γ-ray ionizing radiation on mitochondrial function in mouse hematopoietic stem and progenitor cells (HSPCs). Methods:C57BL/6 mice were divided into control group, 1 Gy irradiation group and 4.5 Gy irradiation group. The mitochondrial functions were detected at 12 h and 24 h after irradiation, including ROS level, membrane potential, mitochondrial structure, and mitochondrial stress. Bone marrow c-Kit + cells received a single 15 Gy irradiation in vitro, after 24 h, mitochondrial function was detected. Results:It was found that mice leukocytes ( t=12.41, 18.31, 16.48, 14.16, 19.08, 20.25, P<0.05), red blood cells ( t=4.81, 6.62, P<0.05) and platelets ( t=4.33, 6.68, P<0.05) were significantly reduced. The numbers of bone marrow colony formation unit ( t=16.27, 55.66, 17.06, 43.75, P<0.05), and HSPCs ( t=5.16, 11.55, P<0.05) were decreased dose-dependently post-irradiation. Under 1 Gy irradiation, the mitochondrial function and mitochondrial basal metabolic index of HSPCs ( t= 7.36, 3.68, 4.58, 3.15, 3.15, P<0.05) were enhanced at 24 h post-irradiation. Under 4.5 Gy irradiation, mitochondrial number, mitochondrial membrane potential ( t=12.29, 10.46, P<0.05), maximal respiration and spare respiratory capacity were decreased ( t=7.81, 5.78, 6.70, 5.83, P<0.05), ROS level was increased ( t=4.63, 4.12, P<0.05). The basal respiration and oxidative phosphorylated ATP production were reduced at 12 h after irradiation ( t=8.48, 3.80, P<0.05); and the proton leakage was increased ( t=6.57, P<0.05) and coupling efficiency was reduced ( t=11.43, P<0.05) at 24 h after irradiation. In cultured c-Kit + cells, the level of ROS ( t=11.30, P<0.05) and the maximum respiration and spare respiratory capacity were increased ( t=4.25, 3.44, P<0.05) while the mitochondrial membrane potential was decreased ( t=34.92, P<0.05) significantly. Conclusions:A method for systematically assessing mitochondrial function in HSPCs was established, and the effect of ionizing radiation on mitochondrial function of HSPCs was clarified, laying a foundation for further revealing the mechanism of ionizing radiation-induced mitochondrial damage in HSPCs.

Objective:To evaluate the effect of pomegranate peel polyphenols on sebum secretion in golden hamsters, and to explore its possible mechanisms.Methods:Thirty golden hamsters were randomly and equally divided into 5 groups: (ointment) vehicle group, 0.48%-, 0.96%-, 1.92%-pomegranate peel polyphenol ointment groups, and retinoic acid cream group. Corresponding cream or ointments were applied to bilateral sebaceous gland spots of the golden hamsters at a dose of 1 gram twice a day for 4 consecutive weeks. The area of bilateral sebaceous gland spots was measured on days 0, 7, 14, 21 and 28 after the start of treatment, which was calculated by the maximum longitudinal diameter multiplied by the maximum transverse diameter. Twenty-four hours after the last treatment, immunohistochemical study was conducted to determine the expression of AKT/Sox9 signaling pathway in sebaceous gland spots resected from the golden hamsters. The area of sebaceous gland spots in these groups at different time points was compared by repeated measures analysis of variance, and other data were analyzed by one-way analysis of variance or Kruskal-Wallis H test. Results:The area of sebaceous gland spots was significantly smaller in the 0.96%-, 1.92%-pomegranate peel polyphenol ointment groups (50.48±2.41 mm 2, 48.24±2.56 mm 2, respectively) and retinoic acid cream group (48.31±2.76 mm 2) than in the vehicle group (57.99±3.29 mm 2; t=2.69, 3.98, 3.65, P=0.012, 0.001, 0.001, respectively) . Sox9 expression was significantly lower in the 1.92%-pomegranate peel polyphenol ointment group (0.39±0.04) and retinoic acid cream group (0.38±0.03) than in the vehicle group (0.44±0.02, P=0.040) . However, there was no significant difference in AKT expression among the 5 groups ( F=1.645, P=0.199) . Conclusion:Pomegranate peel polyphenols can reduce the sebaceous gland spot area and inhibit sebum secretion in golden hamsters, which may be related to the inhibition of Sox9 expression.

Objective To investigate the cumulative effective dose (CED) of ionizing radiation received by patients with Crohn's disease(CD) and to identify the risk factors associated with high levels of radiation in patients with Crohn's disease. Methods A total of 230 patients were enrolled. The classification of CD was according to the Montreal standards, and the CED of each patient was calculated retrospectively based on standards tables. High levels of radiation was defined as no less than 50 mSv CED. Patients who accepted no less than 50 mSv CED were assigned to high level of the radiation group, and those who accepted simultaneously less than 50 mSv CED were assigned to the control group. The risk factors for patients associating with high levels of radiation were analyzed by Logistic regression. Results CT enterography and abdominopelvic CT accounted for 52. 1％ and 39. 6％, respectively, and add up to 91. 7％ of total CED. The mean CED received per patient was 34. 07 mSv (95％ CI:30. 845～37. 304), and 51 patients (22. 2％ of total patients) with CD were exposed to no less than 50 mSv CED. Patients with long disease duration, surgical intervention, ileal location, stricturing or penetrating pattern received a higher dose of radiation. In a Logistic regression, stricturing or penetrating pattern(OR =3. 711, 95％ CI:2. 239 ～ 6. 151, P ＜0. 001) and the requirement for azathioprine (OR =4. 218, 95％ CI: 1. 221 ～14. 579,P=0. 023) were independent risk factors for the high levels of radiation in CD. Conclusion More than one in five of patients with CD are exposed to high levels of ionizing radiation, mainly caused by CT examination. Stricturing or penetrating pattern and the usage of azathioprine are independent risk factors for the high levels exposure of radiation in CD patients. During the clinical management and follow-up, it is important to either monitor the effective dose received per patient, minimizing unnecessary CT examination, or to transform to use no radiation imaging examination, such as MR enterography.