Association between lempel ziv complexity of moderate to vigorous intensity physical activity time series and physical fitness among adolescents / 中国学校卫生

Objective@#To investigate the variability of the time and frequency of Moderate to Vigorous Physical Activity (MVPA) during the school days and weekends of junior high school students, and to explore the correlation between MVPA and physical fitness.@*Methods@#A cluster sampling method was used to investigate 79 students of grade 1 and grade 2 in Beijing Huilongguan Middle School. Adapted one day physical activity recording tool was implemented to investigate students’ physical activity from 8:00 to 23:00 a week, activity records were classified into daily MVPA parts and non MVPA parts based on MET values. Physical activity time series for 5 consecutive days and 2 weekends, as well as MVPA total time and the lempel ziv complexity of the sequence was calculated. Investigated the correlation between the MVPA situation and the results of national students’ physical fitness standard test.@*Results@#There was no statistical difference in MVPA time between males and females during school days( t =-0.90, P >0.05). Females had greater variability in MVPA than males(58.9%, 53.5%). There was also no statistical difference in MVPA complexity between genders( t =-0.55, P >0.05). During weekends, there was no significant difference in the total MVPA time between men and women( t =-0.13, P >0.05). The CV of male MVPA time was lower than that of female(141.5%, 152.8%). There was also no significant difference( t =-0.63, P >0.05), and male MVPA complex CV was slightly higher than that of female ( 55.1% , 48.1%). The MVPA time CV of adolescents during weekdays was slightly lower for males (weekdays vs weekends: 53.5%, 141.5%) than females(58.9%, 152.8%). The MVPA complexity in weekdays among males was moderately correlated with BMI( r =0.41), and the MVPA time and weight of females ( r =-0.30) and BMI ( r =-0.31) were low. The complexity was related to body weight ( r =-0.31) and BMI ( r =-0.33) to a low degree( P <0.05).@*Conclusion@#Junior middle school students are more active on school days than weekend, but the MVPA time series are limited. Schools can effectively improve physical fitness by spreading out the activity period of MVPA in one day. MVPA complexity, as a more comprehensive indicator, may be more sensitive to BMI of junior middle school students.

A meta-analysis of diffusion tensor imaging for diagnosis of early radiation-induced brain injury / 中华放射肿瘤学杂志

Objective To analyze the diagnostic value of diffusion tensor imaging (DTI) for early radiation-induced brain injury.Methods We searched CNKI and PubMed and included articles according to the PRISMA statement.FA value, λ||, and λ丄 were pooled, and Forest plot generation, cumulative analysis, sensitivity analysis, and regression analysis were performed.We also used the funnel plot to analyze publication bias.Results A total 11 studies were included for meta-analysis.The results of FA value heterogeneity test were as follows:P=0.000, I2=93.6% in China;P=0.004, I2=82.2% in other countries and regions;P=0.000, I2=91.5% in all regions.The regression analysis of time-dose dependence and study design showed significant and non-significant associations, respectively, with the heterogeneity of these studies (adjusted P=0.026, P=0.005;adjusted P=0.859, P=0.908).The results of λ||and λ丄 heterogeneity tests were as follows:P=0.908, I2=0.0%;P=0.100, I2=56.6%.There was a sign of publication bias by Egger's test (coefficient:-6.26, 95%CI:-9.31 to-3.20, P=0.001) and Begg's test (P=0.004).Conclusions DTI-derived metrics are sensitive and reliable in the diagnosis of early radiation-induced brain injury.

Evaluation of the value of resting state BOLD-fMRI in radiation-induced brain injury after nasopharyngeal carcinoma radiotherapy / 实用放射学杂志

Objective To analyze the value of resting state BOLD-fMRI in the early diagnosis of brain injury after nasopharyngeal carcinoma radiotherapy.Methods Four groups of nasopharyngeal carcinoma patients,including before radiotherapy group (G0),0-3 months after radiotherapy group (G1), 3-6 months after radiotherapy group (G2) and 6-9 months after radiotherapy group (G3),were underwent a resting state BOLD-fMRI scan, and Matlab software DPARSF tool was used to analyze and postprocess the data based on G1-G0,G2-G0,G3-G0,G2-G1,G3-G2 and G3-G1.Results Compared with the G0 group,the activity of bilateral hippocampus and temporal lobes was decreased in G1 and G2 groups,and the decreased degree in G2 group was smaller than that in G1 group.Compared with G1 group,brain metabolic activity increased in G2 and G3 group,but did not return to the initial level before radiotherapy.Conclusion Abnormal changes of resting state BOLD-fMRI have an important clinical significance in early diagnosis of radiation-induced brain injury after nasopharyngeal carcinoma radiotherapy.

Research progress of functional magnetic resonance imaging in radiation-induced brain injury after head and neck carcinoma radiotherapy / 中华放射肿瘤学杂志

Radiation?induced brain injury is a common adverse reaction to radiotherapy for head and neck carcinoma, and may develop into radiation?induced brain necrosis in some patients. The disease has a substantial impact on the quality of life and 5?year survival in patients. Early diagnosis and prevention are important for the clinical treatment of radiation?induced brain injury. On the other hand, recurrence and pseudoprogression as complications of malignant tumor radiotherapy are also key problems for clinical diagnosis and identification of radiation?induced brain injury. Magnetic resonance imaging ( MRI) , especially functional MRI, provides an important approach for basic and clinical studies of radiation?induced brain injury.