Objective To understand the current situation of healthcare-associated infection(HAI)in China,pro-vide data support and decision-making basis for formulating scientific and effective strategies for HAI prevention and control.Methods A nationwide cross-sectional survey on HAI was conducted among various types and levels of medical institutions in China according to a unified protocol of bedside surveys and case investigations.Results In 2024,a total of 5 736 medical institutions and 2 751 765 patients were surveyed.Among them,34 889 HAI cases were identified,with a prevalence rate of 1.27％.The number of HAI episodes was 38 032,and case prevalence rate was 1.38％.The prevalence rate of HAI in medical institutions in different regions of China ranged from 0.66％to 2.35％.Among medical institutions of different scales,those with a bed capacity of ≥900 had the high-est incidence of HAI,reaching 1.65％.The most common infection site was the lower respiratory tract(44.66％),followed by the urinary tract(12.94％),surgical site(9.32％),upper respiratory tract(7.02％),and bloodstream infection(5.78％).The top 3 departments with the highest HAI rates were the general intensive care unit(10.02％),department of neurosurgery(5.51％),and department(group)of hematology(5.34％).A total of 23 238 strains of HAI pathogens were detected,with 10 714 strains(46.10％)from lower respiratory tract speci-mens.The top 5 detected strains were Klebsiella pneumoniae(14.76％),Pseudomonas aeruginosa(13.33％),Escherichia coli(12.79％),Acinetobacter baumannii(9.23％),and Staphylococcus aureus(7.88％).231 944 pa-tients underwent class Ⅰ incision surgery were monitored,with 1 647 cases experienced surgical site infection,and the prevalence rate of surgical site infection was 0.71％.The number of patients who should undergo pathogen de-tection(patients receiving therapeutic and therapeutic combined prophylactic antimicrobial agents)was 715 179,while the actual number was 480 492,with a pathogen detection rate of 67.18％.425 225 patients received patho-genic detection before treatment,with a detection rate of 59.46％.Conclusion The overall HAI prevalence in Chi-na is lower,showing disparities among medical institutions of different regions and scales.Therefore,precise imple-mentation of measures is necessary for HAI prevention and control,with a focus on high-risk institutions and high-risk departments,key areas,and critical procedures.All levels of medical institutions should continuously reduce the incidence of HAI by strengthening monitoring,standardizing the use of antimicrobial agents,and reinforcing basic HAI prevention and control measures.

Abnormal deployment of the airbag during a frontal car collision can cause injuries to the upper extremity of drivers with non-standard driving postures.Finite element simulation offers an effective approach for evaluating such injury risks.In this study,a biomechanical finite element model of the upper limb of the 95th percentile human body with detailed anatomical structures was developed.The validity of the upper extremity-airbag collision model was confirmed by reconstructing the cadaveric forearm and airbag impact experiments.Based on the validated model,the influence of factors such as airbag mass rate parameters,upper limb grip angle,and grip force on upper limb injuries in frontal collisions was investigated.The results indicate that variations in these three parameters have a significant influence on upper extremity injury,and these factors should be considered in the assessment of upper extremity injuries during car collision.

Objective:To explore the feasibility and efficacy of left ventricular decompression in pediatric patients supported by extracorporeal membrane oxygenation（ECMO）.Methods:The clinical data of 15 children who underwent left ventricular decompression during ECMO in the cardiac intensive care unit（CICU）of Guangzhou Women and Children's Medical Center from February 2021 to August 2023 were retrospectively analyzed.Results:Among the 15 patients，there were 8 males and 7 females,with a median age of 1.1 years old（20 days to 15 years old）and a median weight of 8.5（3.1 to 38.0）kg. Cardiac pathologies varied，including hypertrophic obstructive cardiomyopathy(1 case),left coronary artery abnormalities originating from the pulmonary artery（3 cases），aortic coarctation with ventricular septal defect（1 case），complete transposition of great arteries with ventricular septal defect（1 case），ventricular septal defect with severe mitral valve insufficiency（1 case），fulminant myocarditis（5 cases），tetralogy of Fallot（1 case），ascending aortic aneurysm with aortic valve insufficiency（1 case），and Kawasaki disease complicated with giant aneurysm（1 case）. The venous-arterial ECMO mode was used in all 15 children,9 cases were intubated centrally and 6 cases were intubated peripherally. The reasons for ECMO：low cardiac output（8 cases），cardiogenic shock（5 cases），and frequent ventricular tachycardia and ventricular fibrillation（2 cases）. Extracorporeal cardiopulmonary resuscitation was performed in 3 cases. The median duration of mechanical ventilation was 248 (142-590) h,the median CICU stay was 18 (7-26) d,and the median hospital stay was 28 (7-37) d. Of the 15 children,7 cases underwent emergency left ventricular decompression through a small sternal incision,with a mean decompression time of ECMO-assisted 12.2(9-22) h，and 8 cases underwent selective left ventricular decompression through a median sternal incision. Left ventricular systolic function improved significantly after decompression in all 15 patients，of whom 12 cases were successfully withdrew off ECMO and 10 cases of them survived.Conclusion:Left ventricular decompression can improve the cardiac dysfunction in children with ECMO，reduce the occurrence of complications，and increase the success rate and survival rate of ECMO.

Objective To investigate the risk of thoracoabdominal injuries in six-year-old child occupants in a reclined seating posture during frontal collisions,and provide a reference for developing child restraint systems(CRS).Methods Three validated biomechanical models of six-year-old child occupants in different seating postures with detailed anatomical structures were used.The acceleration curve from a sport utility vehicle crash test was applied to analyze the effects of seating posture on thoracic motion trajectory,chest acceleration,thoracoabdominal compression,viscous criterion(VC)of the chest and abdomen,internal organ strain,and spinal stress.Results Thoracic motion trajectories varied in the Z-direction under three seating postures.As the upper torso angle increased,thoracoabdominal kinematic injury parameters showed an upward trend.The thoracic and abdominal VC under 120° and 135° posture increased by 67％and 113％,10.7％and 25％compared with that under 105° standard sitting posture.The risk of thoracic internal organ injury was inversely related to the seating angle,while the risk of abdominal internal organ injury was positively related to the seating angle.The primary spinal injury mechanism was compression-flexion.Conclusions CRS protection evaluation should comprehensively consider thoracoabdominal kinematic parameters,internal organ biomechanics,and spinal injury risk.These findings have important implications for CRS development in intelligent driving systems and occupant protection strategy formulation.

Objective To explore the changes in neural activity in patients with type 2 diabetes mellitus(T2DM)and their corre-lation with executive function,and to analyze the neural mechanisms underlying the decline in executive function in T2DM patients.Methods Thirty-one T2DM patients(T2DM group)and thirty-two healthy controls(HC)(HC group)matched for body mass index(BMI)underwent resting-state functional magnetic resonance imaging(rs-fMRI)scans and N-back task tests were included.Differ-ences in the amplitude of low-frequency fluctuation(ALFF),regional homogeneity(ReHo),and seed-based functional connectivity(FC)between the two groups were compared,and partial correlation analyses were performed between the difference results and N-back task performance.Results The T2DM group showed prolonged reaction time(RT)in the 1-back and 2-back tasks.T2DM patients exhibited increased ALFF in the bilateral caudate nucleus,left medial superior frontal gyrus,and right postcentral gyrus,as well as elevated ReHo in the right putamen.FC analysis revealed significant alterations in FC between the caudate nucleus,putamen,and multiple brain regions in T2DM patients,with some of these FC changes significantly correlated with RT and accuracy(ACC)in the N-back task.Conclusion The decline in executive function in T2DM patients may be associated with abnormal neural activity in brain regions such as the striatum,salience network,and frontoparietal control network.FC further decreases under increased cognitive load.These findings provide evidence for the study of the neural mechanisms of executive function impairment in T2DM patients.

Based on CT scan data,a bionic model of lumbar spine injuries with high biofidelity is developed and validated through cadaver experiments.Decoupling the constraint system that affects occupants during collisions due to inertial forces and the subsequent pressure exerted by the seat upon returning to position,a simulated fall experiment is designed.The simulated outcomes are trained and predicted using deep learning algorithms,and the accuracy of the trained neural network prediction model is verified.Key parameters are analyzed for correlation using principal component analysis and cross-reverse methods.The results shows that the predicted lumbar spine injury model obtained from training has high reliability(R2>0.9).Comprehensive analysis reveals that after experiencing axial impact,the L4 vertebral body bears the highest impact load and can be used as a representative measure of lumbar spine injury.Among the environmental variables,the axial force on the L4 lumbar spine is mainly affected by torso mass and fall height,both of which have positive correlations.Torso mass,fall height,and posture angle all have positive effects on internal energy.Conversely,torso mass and fall height have negative correlations with stress.These research findings provide a scientific basis for further elucidating lumbar spine injury mechanisms in intelligent cockpit environments,devising corresponding safety protection measures,and evaluating occupant safety in automobiles.

Objective To investigate the risk of thoracoabdominal injuries in six-year-old child occupants in a reclined seating posture during frontal collisions,and provide a reference for developing child restraint systems(CRS).Methods Three validated biomechanical models of six-year-old child occupants in different seating postures with detailed anatomical structures were used.The acceleration curve from a sport utility vehicle crash test was applied to analyze the effects of seating posture on thoracic motion trajectory,chest acceleration,thoracoabdominal compression,viscous criterion(VC)of the chest and abdomen,internal organ strain,and spinal stress.Results Thoracic motion trajectories varied in the Z-direction under three seating postures.As the upper torso angle increased,thoracoabdominal kinematic injury parameters showed an upward trend.The thoracic and abdominal VC under 120° and 135° posture increased by 67％and 113％,10.7％and 25％compared with that under 105° standard sitting posture.The risk of thoracic internal organ injury was inversely related to the seating angle,while the risk of abdominal internal organ injury was positively related to the seating angle.The primary spinal injury mechanism was compression-flexion.Conclusions CRS protection evaluation should comprehensively consider thoracoabdominal kinematic parameters,internal organ biomechanics,and spinal injury risk.These findings have important implications for CRS development in intelligent driving systems and occupant protection strategy formulation.

BACKGROUND:Much of the current research on M2 macrophage-derived exosomes focuses on their effects on wound healing and osteoblast proliferation and differentiation,while few studies have focused on their role in regulating microglia phenotype.OBJECTIVE:To discuss the role and molecular mechanisms of M2 macrophage-derived exosomes in the phenotypic regulation of microglia.MERHODS:(1)Bone marrow primary macrophages were extracted and then stimulated with 50 ng/mL interleukin 4 for 24 hours to promote macrophage M2-type polarization.Flow cytometry and cellular immunofluorescence were used to identify the M2-type macrophage marker CD206.(2)M2 macrophage-derived exosomes were extracted and identified.(3)Microglia BV2 were randomly divided into three groups:control group,lipopolysaccharide group,and treatment group.No treatment was done in the control group.500 ng/mL lipopolysaccharide was added to the intervention for 24 hours in the lipopolysaccharide group.500 ng/mL lipopolysaccharide and 25 μg/mL M2 macrophage-derived exosomes were added simultaneously to the treatment group for 24 hours.ELISA was performed to detect the secretion of tumor necrosis factor α and interleukin 10 in the culture supernatant.qRT-PCR was performed to detect the mRNA expression of inducible nitric oxide synthase,arginase 1,interleukin 1β,and interleukin 10 in the cells.Western blot assay was performed to detect the protein expression of inducible nitric oxide synthase,arginase 1,and nuclear factor-κB signaling pathway related protein expression.RESULTS AND CONCLUSION:(1)ELISA results showed that the secretion of tumor necrosis factor α was significantly increased in the lipopolysaccharide group compared with the control group.The secretion of tumor necrosis factor α was reduced and the secretion of interleukin 10 was increased in the treatment group compared with the lipopolysaccharide group.(2)The qRT-PCR results showed that compared with the control group,the mRNA expression of interleukin 1β and inducible nitric oxide synthase increased in the lipopolysaccharide group.Compared with the lipopolysaccharide group,the mRNA expression of interleukin 1β and inducible nitric oxide synthase decreased,and the mRNA expression of interleukin 10 and arginase 1 increased in the treatment group.(3)Western blot assay results showed that the expression of inducible nitric oxide synthase protein was increased in the lipopolysaccharide group compared with the control group.The expression of inducible nitric oxide synthase protein was decreased and the expression of arginase 1 protein was elevated in the treatment group compared with the lipopolysaccharide group.(4)Compared with the control group,the expression of p65 and p-IκB-α proteins in the nuclear factor-κB signaling pathway was reduced in the lipopolysaccharide group,whereas the expression of p65 and p-IκB-α proteins was elevated in the treatment group compared with the lipopolysaccharide group.The results showed that M2-type macrophage-derived exosomes could significantly inhibit lipopolysaccharide-induced inflammatory responses in microglia,enhance the expression of the anti-inflammatory factor interleukin 10,suppress the expression of the pro-inflammatory factors tumor necrosis factor α and interleukin 1β,and promote microglial cell phenotypes polarized from the M1-type to the M2-type.The mechanism may be related to the inhibition of nuclear factor-κB signaling pathway activation by M2-type macrophage-derived exosomes.

Objective The finite element pelvis model with detailed anatomical structures which meets the Chinese human 95th percentile characteristics is developed,and the influence of cortical bone modeling method on the biomechanical response of the real pelvis is explored.Methods Based on the pelvic medical images of a 95th percentile male volunteer,two finite element pelvis models with real hip bone cortical bone thickness(REA-M)and 2 mm uniform cortical bone thickness(CON-M)dominated by hexahedral elements were constructed.Using the simulation method to reconstruct the loading conditions of cadaver experiments,the validation of models was verified by comparing the cadaver experimental results and simulation results,and biomechanical response differences of two models under different working conditions were discussed.Results The simulation data showed that there was a strong correlation between the overall biomechanical responses of two pelvic models and the cadaver experiment,and the mechanical response difference between two models was mostly within 8％,and the correlation score difference between two models was smaller than 2％.Conclusions The validation of two pelvic models established in this study is verified by rebuilding multiple simulation experiments.Although the biomechanical responses of CON-M and REA-M models were different,the difference was small.From the perspective of model simplification,the CON-M model can be used to study the biomechanical response of the pelvis.

Background and Aims:Obstructive jaundice(OJ)caused by common bile duct stones(CBDS)is a major risk factor for acute cholangitis(AC).Early identification of high-risk patients is essential for improving prognosis.Soluble CD163(sCD163)and milk fat globule epidermal growth factor 8(MFG-E8)are associated with inflammatory diseases,but their predictive value for AC in CBDS-related OJ remains unclear.This study aimed to evaluate the predictive significance of serum sCD163 and MFG-E8 levels for AC in patients with CBDS-OJ.Methods:A total of 142 patients with CBDS-OJ admitted from January 2022 to June 2024 were included as the observation group,and 145 healthy individuals undergoing physical examination served as controls.Serum sCD163 and MFG-E8 levels were measured using ELISA.Based on the occurrence of AC within 24 hours after admission,patients with CBDS-OJ were divided into an AC group(n=48)and a non-AC group(n=94).Clinical variables and serological indicators were compared between groups.Multivariate logistic regression was used to identify independent factors associated with AC.Receiver operating characteristic(ROC)curves were generated to assess the predictive performance of sCD163,MFG-E8,and their combination.Results:Compared with the control group,patients with CBDS-OJ showed significantly elevated serum sCD163 levels and decreased MFG-E8 levels(both P<0.05).Within the observation group,the AC group had higher AST,ALT and sCD163 levels and lower MFG-E8 levels than the non-AC group(all P<0.05).Logistic regression identified elevated sCD163 as an independent risk factor(OR=3.478,P<0.001)and reduced MFG-E8 as a protective factor(OR=0.526,P=0.020)for AC.ROC analysis showed AUC values of 0.759 for sCD163,0.787 for MFG-E8,and 0.920 for their combined detection,with the combined model outperforming either marker alone(P<0.001).Conclusion:Serum sCD163 elevation and MFG-E8 reduction are closely associated with the development of AC in patients with CBDS-OJ.Combined detection of sCD163 and MFG-E8 provides superior predictive value and may serve as a useful tool for early risk stratification in clinical practice.