Objective: To investigate the association between medium to long term PM 2.5 exposure around school areas and overweight/obesity among primary and secondary school students in Guangxi, providing data support and theoretical foundations for scientifically addressing overweight and obesity in primary and secondary school students. Methods: From September to November 2023, a stratified cluster random sampling method was employed to select 251 183 students aged 7-18 years (grade 1 to grade 12) from 14 prefecture level cities (111 districts and counties) in Guangxi. PM 2.5 mass concentration data were obtained from the Tracking Air Pollution in China (TAP) dataset. Preliminary comparative analysis was conducted using the Mann-Whitney U test, while binary Logistic regression models were applied to quantify the relationship between PM 2.5 exposure and overweight/obesity. Restricted cubic spline analysis was further utilized to examine the nonlinear association between PM 2.5 concentration and overweight/obesity risk. Results: The detection rate of overweight/obesity among Guangxi students in 2023 was 19.5%. The median PM 2.5 concentration in the year prior to the study was higher in the overweight/obesity group (23.22 μg/m 3) compared to the non overweight/obesity group (22.63 μg/m 3) ( Z=-15.66, P <0.01), and consistent trends were observed across gender (male/female) and educational stage (primary/junior/senior high school) subgroups (all P <0.01). Binary Logistic regression revealed that for every 10 μg/m 3 increase in the annual average PM 2.5 concentration, the risk of overweight/obesity increased by 12% ( OR=1.12, 95%CI=1.09- 1.15 , P <0.01). Restricted cubic spline analysis indicated a nonlinear relationship between monthly PM 2.5 levels and overweight/obesity risk ( P trend <0.01). Below 22.68 μg/m 3, PM 2.5 exposure showed no significant association with obesity risk; above the threshold, the risk increased with rising PM 2.5 levels. Conclusion Medium to long term PM 2.5 exposure around school environments is significantly associated with overweight/obesity among primary and secondary school students.

Objective To investigate the protective effect of polydatin(PLD)on primary cultured rat cortical neurons induced by β-amyloid protein(Aβ25-35)and its possible mechanism.Methods Cortical neurons were isolated from SD rats and primarily cultured,and then divided into control group,PLD group,Aβ25-35 group and Aβ25-35+PLD group.Cell viability was detected by MTT as-say,intracellular and mitochondrial reactive oxygen species(ROS)levels were detected by dichlo-rofluorescein diacetic acid probe or MitoSOX Red staining,opening of mitochondrial membrane permeability transition pore(MPTP)was detected by MPTP kit,and contents of cytochrome C(Cyt C)and mitochondrial transcription factor A(TFAM)were detected by Western blotting.In addition,the activity of intracellular electron transport chain complexes(including complexes Ⅰ,Ⅱ,Ⅲ and Ⅳ)and the level of adenylate triphosphate(ATP)were determined.High performance liquid chromatography(HPLC)was conducted to determine the content of 8-hydroxydeox-yguanosine(8-OHdG)in the mitochondria.Results Compared with the control group,cell vitali-ty,mitochondrial fluorescence intensity,activities of mitochondrial respiratory chain enzymes(complex Ⅰ,Ⅱ,Ⅲ and Ⅳ),intracellular ATP and mitochondrial TFAM expression were signifi-cantly decreased in the cortical neuron from the Aβ25～35 group(P＜0.05,P＜0.01).Compared with the Aβ25-35 group,mitochondrial fluorescence intensity,mitochondrial respiratory chain enzyme activity(complex Ⅰ,Ⅱ,Ⅲ,Ⅳ),intracellular ATP and mitochondrial TFAM expression were obviously increased in the PLD group,and intracellular and mitochondrial ROS levels were nota-bly decreased after cortical neuron exposure for 3,6,12 and 24 h(P＜0.05,P＜0.01).The ratio of cytoplasmic/mitochondrial Cyt C and mitochondrial level of 8-OHdG were statistically lower in the Aβ25-35+PLD group than the Aβ25-35 group[3.02±0.28 vs 5.73±0.45,P＜0.05;(8.07±1.45)× 106 dG vs(16.07±2.29)X 106 dG,P＜0.05].Conclusion PLD can effectively protect cortical neu-rons against Aβ25-35-induced injury,which may be partially by its inhibiting mitochondrial oxida-tive stress and improving mitochondrial function.

Objective To investigate the value of polar residual network(PResNet)model for assisting evaluation on rat myocardial infarction(MI)segment in myocardial contrast echocardiography(MCE).Methods Twenty-five male SD rats were randomly divided into MI group(n=15)and sham operation group(n=10).MI models were established in MI group through ligation of the left anterior descending coronary artery using atraumatic suture,while no intervention was given to those in sham operation group after thoracotomy.MCE images of both basal and papillary muscle levels on the short axis section of left ventricles were acquired after 1 week,which were assessed independently by 2 junior and 2 senior ultrasound physicians.The evaluating efficacy of MI segment,the mean interpretation time and the consistency were compared whether under the assistance of PResNet model or not.Results No significant difference of efficacy of evaluation on MI segment was found for senior physicians with or without assistance of PResNet model(both P＞0.05).Under the assistance of PResNet model,the efficacy of junior physicians for diagnosing MI segment was significantly improved compared with that without the assistance of PResNet model(both P＜0.01),and was comparable to that of senior physicians.Under the assistance of PResNet model,the mean interpretation time of each physician was significantly shorter than that without assistance(all P＜0.001),and the consistency between junior physicians and among junior and senior physicians were both moderate(Kappa=0.692,0.542),which became better under the assistance(Kappa=0.763,0.749).Conclusion PResNet could improve the efficacy of junior physicians for evaluation on rat MI segment in MCE images,shorten interpretation time with different aptitudes,also improve the consistency to some extent.

Masquelet technique has become a safe and effective treatment for chronic osteomyelitis of the long limb shaft. The vast majority of osteomyelitis can be ultimately controlled, segmental bone defects repaired and limb functions restored. Accumulation of clinical applications and development of imaging technology have led to rapid progress in determining the infection scope of chronic limb osteomyelitis, precise preoperative design for repair of soft tissue defects, evaluation of bone structure stability, and use of bone grafting materials. This article reviews the progress of Masquelet technique in the treatment of chronic limb osteomyelitis from the aspects of its theoretical foundation, key operations, and selection of fixation methods, hoping to deepen the understanding of current Masquelet technique.

Objective:To compare the failure risks between restricted and unrestricted cephalomedullary nail sliding during InterTAN intramedullary nail fixation for intertrochanteric fractures in the elderly patients.Methods:A retrospective study was conducted to analyze the data of 192 elderly patients with intertrochanteric fracture who had been admitted to Department of Orthopaedics, The Seventh Medical Center, General Hospital of the People's Liberation Army from January 2021 to December 2022. The patients were divided into 2 groups based on whether the set screws were tightened or not during surgery. In the observation group of 78 cases, there were 31 males and 47 females with an age of (80.2±7.7) years, and 23 cases of type 31-A1 and 55 cases of type 31-A2 by the AO classification. Their set screws were not tightened during surgery to allow the cephalomedullary nail sliding. In the control group of 114 cases, there were 40 males and 74 females with an age of (81.6±7.8) years, and 42 cases of type 31-A1 and 72 cases of type 31-A2. Their set screws were tightened during surgery to restrict the cephalomedullary nail sliding. The incidence of postoperative fixation complications and sliding distances of the cephalomedullary nail within 1 year after surgery were compared between the 2 groups in the total fractures and in the stable and unstable fractures as well.Results:There was no statistically significant difference in the preoperative general data between the 2 groups of patients, indicating comparability ( P>0.05). The incidence of fixation complications within 1 year after surgery was 5.1% (4/78) for the observation group and 12.3% (14/114) for the control group, showing no statistically significant difference between the 2 groups ( P>0.05). The sliding distance of the cephalomedullary nail in the observation group [7.05 (6.00, 8.25) mm] was significantly larger than that in the control group [5.65 (3.55, 7.00) mm] ( P<0.05). For stable fractures, the incidence of fixation complications within 1 year after surgery was 7.1% (2/28) for the observation group and 7.0% (3/43) for the control group, showing no statistically significant difference ( P>0.05), and the sliding distance of the cephalomedullary nail in the observation group [6.00 (5.25, 7.00) mm] was significantly greater than that in the control group [3.05 (2.00, 5.00) mm] ( P<0.05). For unstable fractures, the incidence of fixation complications within 1 year after surgery for the observation group patients [4.0% (2/50)] was significantly lower than that for the control group patients [15.5% (11/71)], and the sliding distance of the cephalomedullary nail in the observation group [8.00 (6.70, 10.00) mm] was significantly greater than that in the control group [6.00 (4.87, 7.57) mm] ( P<0.05). Conclusions:In the InterTAN intramedullary nail fixation for intertrochanteric fractures in the elderly patients, tightening of set screws is crucial because it not only increases the stability but also limits compression at the fracture site. It is recommended not to tighten the set screws for unstable fractures, but further observation is needed before it can be determined whether the set screws should be tightened or not for stable fractures.

Objective:To develop and validate a risk model of postoperative 3-year all-cause mortality for the elderly patients with hip fracture.Methods:A retrospective study was conducted to analyze the clinical data of 325 elderly patients with hip fracture who had been treated at The Fourth Medical Center, The General Hospital of PLA from January 2020 to December 2021. There were 90 men and 235 women with an age of (80.9±8.9) years, and 191 intertrochanteric fractures and 134 femoral neck fractures. The patients with hip fractures admitted from January 2020 to June 2021 were assigned to a modeling group (244 cases), and those admitted from July to December 2021 to a validation group (81 cases). Recorded were age, gender, fracture type, pre-injury disease, hematological indicators, time from injury to surgery, previous use of anticoagulant drugs, bone density, American Society of Anesthesiologists (ASA) grading, body mass index, and blood transfusion volume in the 2 groups of patients. The data in the modeling group were used to screen the independent risk factors for the postoperative 3-year all-cause mortality in the elderly patients with hip fracture through logistic regression analysis and receiver operating characteristic (ROC) curve analysis and consequently to construct a prediction model. The data in the validation group were used to analyze the predictive performance of the model through the ROC curve, and the fitting degree of the model was evaluated using the Hosmer-Lemeshow goodness-of-fit test.Results:Respectively, 75 cases in the modeling group and 29 cases in the validation group died 3 years after surgery. There was no statistically significant difference in the baseline data between the 2 groups, indicating comparability ( P>0.05). Logistic univariate analysis showed that gender, age, coronary atherosclerotic heart disease before injury, stroke before injury, pulmonary infection before injury, hemoglobin, albumin, high-density lipoprotein, body mass index, time from injury to surgery and ASA grade were related to the mortality of patients 3 years after surgery ( P<0.05). The ROC curve analysis showed that the variables with predictive ability included age, hemoglobin, albumin, body mass index, and time from injury to surgery. Logistic multivariate analysis showed male, age ≥ 83 years, pre-injury stroke, time from injury to surgery ≥ 4.5 days, ASA grade Ⅲ, and ASA grade Ⅳ were significantly related to the postoperative 3-year all-cause mortality in the elderly patients with hip fracture ( P<0.05). In the prediction model based on the above indicators, the area under the ROC curve was 0.792 (95% CI: 0.730 to 0.855, P<0.001), the cutoff value 0.459, sensitivity 56%, and specificity 90.5%, showing a good fit of the model ( χ2=5.818, P=0.668). Conclusions:Male, age ≥ 83 years, pre-injury stroke, time from injury to surgery ≥ 4.5 days, and ASA grades Ⅲ and Ⅳ are risk factors for postoperative 3-year all-cause mortality in the elderly patients with hip fracture. The risk prediction model based on these indicators demonstrates good predictive efficacy.

ObjectiveSerum metabolomics of acute lung injury（ALI） in rats was conducted using ultra-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry（UPLC-Q-TOF-MS） to explore the similarities and differences in the mechanism of Qingqiao（harvested when the fruits of Forsythiae Fructus were initially ripe and still green in color） and Laoqiao（harvested when the fruits of Forsythiae Fructus were ripe） in the treatment of ALI. MethodA total of 24 SD male rats were acclimatized and fed for 1 week， 6 of them were randomly selected for the blank group and 18 for the experimental group. The ALI model was induced in the experimental group by tracheal intubation with lipopolysaccharide（LPS）. After successfully constructing the ALI model， these rats was randomly divided into model group， Qingqiao group and Laoqiao group， with 6 rats in each group. The Qingqiao and Laoqiao groups were administered orally once a day at a dose of 1.5 g·kg^-1， while the blank and model groups received an equivalent volume of saline for 3 consecutive days. The pathological conditions of rat lung tissues were comprehensively assessed by hematoxylin-eosin（HE） staining， wet-to-dry mass ratio（W/D） of lung tissues， and protein concentration in rat bronchoalveolar lavage fluid（BALF）. The levels of interleukin（IL）-6， IL-1β and tumor necrosis factor（TNF）-α in BALF were quantified using enzyme-linked immunosorbent assay（ELISA）. UPLC-Q-TOF-MS was used to identify and analyze the chemical compositions of Qingqiao and Laoqiao， and serum metabolomics of rats in each group was analyzed， combined with multivariate statistical analysis with variable importance in the projection（VIP） value>1， P<0.05 from t-test， and fold change（FC）≥1.5 or FC≤0.5 to screen the differential metabolites Qingqiao and Laoqiao for the treatment of ALI. The Kyoto Encyclopedia of Genes and Genomes（KEGG） database was used in combination with MetaboAnalyst for the metabolic pathway analysis of the screened differential metabolites. ResultCompared with the blank group， rats in the model group exhibited enlarged alveolar lumen， ruptured alveoli， interstitial hemorrhage， bronchial exudation of a large number of neutrophils and erythrocytes， and a significant increase in the protein concentration in the BALF and the W/D value of the lung tissues（P<0.01）. In contrast， compared with the model group， rats in the Qingqiao group and the Laoqiao group showed reduced bronchial hemorrhage in the lungs， and the protein concentration in the BALF and the W/D value of the lung tissues were significantly decreased（P<0.01）， the lung injury was significantly alleviated， but more obvious in the Qingqiao group. Compared with the blank group， the expression levels of IL-6， IL-1β and TNF-α in the BALF of the model group were significantly higher（P<0.01）. Additionally， compared with the model group， the expression levels of IL-6， IL-1β and TNF-α in the Qingqiao and Laoqiao groups were significantly lower（P<0.01）. The chemical composition analysis of Qingqiao and Laoqiao revealed that 63 components were detected in Qingqiao and 55 components were detected in Laoqiao， with 47 common components， 16 components unique to Qingqiao and 8 components unique to Laoqiao. Characterizing the differences in serum metabolomics in rats， 19 and 12 metabolites were called back by Qingqiao and Laoqiao， respectively. The metabolic pathway enrichment analysis showed that Qingqiao exerted its therapeutic effects by affecting 6 key metabolic pathways， including linoleic acid metabolism， phenylalanine metabolism， phenylalanine， tyrosine and tryptophan biosynthesis， glycerophospholipid metabolism， α-linolenic acid metabolism， and arachidonic acid metabolism， and Laoqiao exerted therapeutic effects by affecting 6 key metabolic pathways， including linoleic acid metabolism， arachidonic acid metabolism， sphingolipid metabolism， phenylalanine metabolism， ascorbate and aldarate metabolism， and glycerophospholipid metabolism. ConclusionQingqiao and Laoqiao have therapeutic effects on ALI， and Qingqiao is more effective. Both of them can play a therapeutic role in ALI by regulating amino acid metabolism and lipid metabolism， but the metabolic pathways affected by them are different.

Objective: To investigate the prevalence of Internet addiction and depression of students, and to analyze the co-occurrence and trend, so as to provide a theoretical basis for prevention and controlling measures of Internet addiction and depression. Methods: A total of 6 317,7 152,81 808,71 180 and 89 932 students aged 10 to 24 years from 12 leagues (103 banners) in Inner Mongolia Autonomous Region were selected by stratified random cluster sampling in September each year from 2017 to 2021. The Internet Addiction Scale and the Central for Epidemiologic Studies Depression Scale(CES-D) was used to measure Internet addiction and depression. And the annual inspection rate, group difference and annual change trend in students were calculated. Multivariate linear regression and restricted cubic spline analysis were used to estimate the linear and non linear associations between Internet addiction and depression in students. Results: The Internet addiction proportion in students gradually decreased from 4.1% in 2017 to 2.1% in 2020, but increased to 3.9% in 2021. And the depressive symptoms proportion increased from 20.9% in 2017 to 28.0% in 2020 and 27.0% in 2021. The detection rate of Internet addiction and depression comorbidities remained at 1.8% to 2.5 %. The Internet addiction proportion in boys was higher than that in girls( χ 2=42.82， P <0.05). The depressive symptoms prevalence in girls was higher than that in boys( χ 2= 553.90， P <0.05). Taking reversal in prevalence of Internet addiction in urban and rural areas was observed in 2019. The detection rates of depressive symptoms and comorbidity were higher in urban areas than these in suburban counties on the whole, and the difference showed a trend of decreasing or even equalizing year by year. Internet addiction was positively correlated with depressive symptoms score ( B=1.67, 95%CI =1.64-1.71), the proportion of depressive symptoms ( OR=1.39, 95%CI =1.38-1.41) and the proportion of major depressive symptoms ( OR=1.35, 95%CI =1.33-1.36) among students in 2021 ( P <0.05). An N-shaped curve was found in the significant nonlinear associations between internet addiction and depression across sex, region and school stage. Conclusion Internet addiction and depression in students show significant linear and non-linear associations, which are consistent in different sexes, regions and school stages. Therefore, relevant measures should be made and implemented in each region, especially in suburb areas, so as to prevent the increasingly development of adolescents and children s Internet addiction and depression.

Objective:To analyze the relationship between dietary composition of residents in endemic fluorosis areas and skeletal fluorosis.Methods:A case-control study was used to analyze the difference of dietary composition between patients with skeletal fluorosis (case group) and residents without skeletal fluorosis (control group). In August 2019, taking the drinking water-borne endemic fluorosis area in Wenshui County, Lvliang City, Shanxi Province as the survey site, a cluster sampling method was adopted to select local residents aged over 18 years old, and a questionnaire survey was conducted by face-to-face interview. The survey contents included gender, age and consumption frequency of various foods. Binary logistic regression was used to analyze the relationship between food consumption frequency and skeletal fluorosis. The diagnosis of skeletal fluorosis was made by using portable digital radiography (DR) to take X-ray films of forearm and lower leg, combining with clinical signs, and according to the Diagnostic Standard for Endemic Skeletal Fluorosis (WS/T 192-2008) to determine.Results:A total of 1 061 subjects were included in this study, including 376 in the case group and 685 in the control group. The age composition of patients in the case group (≤60, > 60 years old: 162, 214 cases) was significantly different from that in the control group (≤60, > 60 years old: 423, 261 cases, χ 2 = 34.52, P < 0.001). There was no statistically significant difference in gender ratio (χ 2 = 1.37, P = 0.251). The proportion of patients in the case group who ate meat and eggs > 1 time/week was lower than that in the control group (χ 2 = 8.06, 5.46, P < 0.05), the proportion of patients who ate milk > 1 time/week was higher than that in the control group (χ 2 = 4.01, P = 0.046), and the proportion of patients who ate seafood ≥1 time/week was lower than that in the control group (χ 2 = 4.16, P = 0.046). The results of binary logistic regression analysis showed that after adjusting for age, sex, and urinary fluoride, the frequency of eating meat, eggs or milk > 1 time/week and the frequency of eating seafood ≥1 time/week were not related to the risk of skeletal fluorosis ( P > 0.05); however, in the group ≤60 years old, the frequency of eating eggs > 1 time/week was associated with the risk of skeletal fluorosis [odds ratio ( OR) = 0.59, 95% confidence interval ( CI): 0.39, 0.88]. Conclusions:The consumption frequency of meat, milk, eggs and seafood is significantly different between the skeletal fluorosis patients and the control people. In the population ≤60 years old, consumption frequency of eggs > 1 time/week may reduce the risk of skeletal fluorosis.