Skeletal muscle dysfunction is a common extra-pulmonary complication in patients with chronic ob-structive pulmonary disease(COPD),significantly impacting exercise capacity and quality of life,leading to a poorer prognosis and increased mortality.Oxidative stress closely associates with the development and progression of skeletal muscle dysfunction in COPD.Exercise,a core component of pulmonary rehabilitation,stands as the primary non-pharma-cological treatment for skeletal muscle dysfunction in COPD patients and exerts a positive modulating effect on oxidative stress.This paper reviews the effects of oxidative stress on skeletal muscle dysfunction in COPD and discusses the mecha-nisms by which exercise improves skeletal muscle dysfunction in COPD from an anti-oxidative stress perspective.It has been found that oxidative stress affects the structure and function of muscles in COPD patients by upregulating the protein hydrolysis system,disrupting mitochondrial function,and impairing calcium homeostasis.Mechanisms by which exercise modulates oxidative stress to improve skeletal muscle dysfunction include the activation of antioxidant genes such as silent mating type information regulation 2 homolog 1 and nuclear factor erythroid 2 related factor to enhance the body's antioxi-dant capacity,inhibiting muscle atrophy.Exercise also regulates mitochondrial reactive oxygen species metabolism,im-proving mitochondrial function,and reduces oxidase activity to protect sarcoplasmic reticulum calcium regulation.In con-clusion,the regulation of skeletal muscle oxidative stress by exercise is a crucial target for improving skeletal muscle dys-function in COPD.

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.

Objective:To explore the diagnostic value of ultrasound for retained products of conceptions com-plicated with uterine arteriovenous fistula(UAVF)after early pregnancy miscarriage and the predictive value for massive bleeding by constructing a risk model for bleeding.Methods:A total of 90 patients who were diagnosed by ultrasound in West China Second Hospital of Sichuan University as having retained products of conceptions complicated with UAVF after early pregnancy miscarriage from July 2013 to September 2021 were selected,among which 37 cases underwent digital subtraction angiography(DSA).Clinical and ultrasound data were collected and statistical analysis was conducted on the ultrasound parameters of whether DSA examination was accompanied by UAVF and whether there was major bleeding(spontaneous and intraoperative).We performed multivariate Lo-gistic regression analysis on parameters with statistical differences,plotted receiver operating characteristic(ROC)curve for predicting major bleeding(spontaneous and intraoperative),and calculated the area under the curve(AUC).Results:① After DSA examination,14 out of 37 patients(37.8%)were diagnosed with UAVF based on ultrasound diagnosis of pregnancy residue combined with UAVF.Univariate and multivariate Logistic an-alyses showed that the expanding inner diameter of blood vessels was an independent risk factor for residual pregnancy products combined with UAVF after early pregnancy miscarriage(OR 37.099,P=0.027).ROC curve analysis revealed that dilated vessel diameter had an AUC of 0.78,sensitivity of 64%,specificity of 91%,and an optimal cut-off value of 0.85 cm for the diagnosis of UAVF.②Out of 90 patients,44(48.9%)experienced sponta-neous massive bleeding.Univariate and multivariate Logistic analyses showed that the presence of vascular pools or dilated vessels was an independent risk factor for spontaneous massive bleeding(OR 5.163,P=0.004).③A-mong70 patients undergoing surgical treatment,7 experienced intraoperative bleeding(11.7%).Univariate and multivariate Logistic analyses showed that the enlargement of the maximum diameter of the lesion was an inde-pendent risk factor for intraoperative massive bleeding(OR 7.278,P=0.007).ROC curve analysis revealed that the AUC of the maximum diameter of the lesion for predicting the risk of intraoperative bleeding was 0.92,with a sensitivity of 100%,specificity of 82%,and an optimal threshold of 3.95 cm.Conclusions:Dilated vessel diameter in ultrasound examination parameters has high diagnostic value for residual pregnancy products combined with UAVF after early pregnancy miscarriage.Patients with vascular pools or dilated vessels and large lesions have a higher risk of spontaneous and intraoperative bleeding,and clinical prediction models can be used to assess risk of bleeding.

Objective:To explore the diagnostic value of ultrasound for retained products of conceptions com-plicated with uterine arteriovenous fistula(UAVF)after early pregnancy miscarriage and the predictive value for massive bleeding by constructing a risk model for bleeding.Methods:A total of 90 patients who were diagnosed by ultrasound in West China Second Hospital of Sichuan University as having retained products of conceptions complicated with UAVF after early pregnancy miscarriage from July 2013 to September 2021 were selected,among which 37 cases underwent digital subtraction angiography(DSA).Clinical and ultrasound data were collected and statistical analysis was conducted on the ultrasound parameters of whether DSA examination was accompanied by UAVF and whether there was major bleeding(spontaneous and intraoperative).We performed multivariate Lo-gistic regression analysis on parameters with statistical differences,plotted receiver operating characteristic(ROC)curve for predicting major bleeding(spontaneous and intraoperative),and calculated the area under the curve(AUC).Results:① After DSA examination,14 out of 37 patients(37.8%)were diagnosed with UAVF based on ultrasound diagnosis of pregnancy residue combined with UAVF.Univariate and multivariate Logistic an-alyses showed that the expanding inner diameter of blood vessels was an independent risk factor for residual pregnancy products combined with UAVF after early pregnancy miscarriage(OR 37.099,P=0.027).ROC curve analysis revealed that dilated vessel diameter had an AUC of 0.78,sensitivity of 64%,specificity of 91%,and an optimal cut-off value of 0.85 cm for the diagnosis of UAVF.②Out of 90 patients,44(48.9%)experienced sponta-neous massive bleeding.Univariate and multivariate Logistic analyses showed that the presence of vascular pools or dilated vessels was an independent risk factor for spontaneous massive bleeding(OR 5.163,P=0.004).③A-mong70 patients undergoing surgical treatment,7 experienced intraoperative bleeding(11.7%).Univariate and multivariate Logistic analyses showed that the enlargement of the maximum diameter of the lesion was an inde-pendent risk factor for intraoperative massive bleeding(OR 7.278,P=0.007).ROC curve analysis revealed that the AUC of the maximum diameter of the lesion for predicting the risk of intraoperative bleeding was 0.92,with a sensitivity of 100%,specificity of 82%,and an optimal threshold of 3.95 cm.Conclusions:Dilated vessel diameter in ultrasound examination parameters has high diagnostic value for residual pregnancy products combined with UAVF after early pregnancy miscarriage.Patients with vascular pools or dilated vessels and large lesions have a higher risk of spontaneous and intraoperative bleeding,and clinical prediction models can be used to assess risk of bleeding.

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.

Skeletal muscle dysfunction is a common extra-pulmonary complication in patients with chronic ob-structive pulmonary disease(COPD),significantly impacting exercise capacity and quality of life,leading to a poorer prognosis and increased mortality.Oxidative stress closely associates with the development and progression of skeletal muscle dysfunction in COPD.Exercise,a core component of pulmonary rehabilitation,stands as the primary non-pharma-cological treatment for skeletal muscle dysfunction in COPD patients and exerts a positive modulating effect on oxidative stress.This paper reviews the effects of oxidative stress on skeletal muscle dysfunction in COPD and discusses the mecha-nisms by which exercise improves skeletal muscle dysfunction in COPD from an anti-oxidative stress perspective.It has been found that oxidative stress affects the structure and function of muscles in COPD patients by upregulating the protein hydrolysis system,disrupting mitochondrial function,and impairing calcium homeostasis.Mechanisms by which exercise modulates oxidative stress to improve skeletal muscle dysfunction include the activation of antioxidant genes such as silent mating type information regulation 2 homolog 1 and nuclear factor erythroid 2 related factor to enhance the body's antioxi-dant capacity,inhibiting muscle atrophy.Exercise also regulates mitochondrial reactive oxygen species metabolism,im-proving mitochondrial function,and reduces oxidase activity to protect sarcoplasmic reticulum calcium regulation.In con-clusion,the regulation of skeletal muscle oxidative stress by exercise is a crucial target for improving skeletal muscle dys-function in COPD.

This study explores the application effect of the case-based teaching method based on Xuexitong learning platform in the online teaching of Digestive System, and analyzes the learner's emotional experience, learning behavior, and learning effect in the case-based online teaching. The results of the study show that the case-based online teaching model based on Xuexitong learning platform improves students' online learning interest, and the students have good emotional experience, high learning enthusiasm, good classroom interaction, enhanced self-learning ability before and after class, and good learning effect. In addition, precise teaching can be used for individual students who are not enthusiastic about online learning.

Objective:To investigate the effects of a novel retrograde tibial nail (RTN) in the treatment of distal tibial fractures.Methods:A retrospective study was conducted in the 11 patients with distal tibial fracture who had been admitted to Department of Traumatic Orthopedics, The Second Affiliated Hospital, Hengyang Medical School from July 2020 to July 2021. There were 5 male and 6 females, aged from 18 to 70 years (average 54.7 years). By the AO/OTA classification, there were 7 extra-articular distal fractures (3 cases of type 43-A1, 3 cases of type 43-A2 and one type 43-A3) and 4 intra-articular fractures (2 cases of type 43-C1 and 2 cases of type 43-C2); by the Gustilo classification, there were 7 closed fractures and 4 open fractures (2 cases of type I and 2 cases of type Ⅱ). All fractures were fixated with a novel RTN. Deformities like distal tibial varus and valgus as well as fracture-related complications were observed after operation while the curative effects evaluated by the ankle-hindfoot score of the American Orthopaedic Foot and Ankle Society (AOFAS).Results:This cohort was followed up for an average of 7.4 months (from 5 to 12 months). All patients obtained clinical union and recovered daily life and work. Radiographic evaluation showed no distal tibial varus or valgus. There were no such complications as postoperative infection, exposure of bone and internal fixation, compartment syndrome, or neurovascular lesion. According to the ankle-hindfoot score of AOFAS, 7 cases were excellent and 4 cases good.Conclusion:This novel retrograde tibial nail may result in good efficacy in the treatment of distal tibial fracture, but its advantages still need further verification.

Objective:To establish a nomogram model for predicting the risk of coronary artery disease in elderly patients with acute myocardial infarction (AMI).Methods:The clinical data of elderly patients with AMI who underwent coronary angiography in the department of cardiology of Cangzhou Central Hospital from July 2015 to March 2020 were analyzed, including age, gender, smoking history, underlying diseases, family history, blood pressure, left ventricular ejection fraction (LVEF), and several biochemical indicators at admission, such as total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), lipoprotein [Lp(a)], apolipoproteins (ApoA, ApoB), ApoA/B ratio, total bilirubin (TBil), direct bilirubin (DBil), indirect bilirubin (IBil), fasting blood glucose (FBG) and uric acid (UA). Patients were divided into model group (2 484 cases) and validation group (683 cases) according to the ratio of 8∶2. According to Gensini score, the model group and validation group were divided into mild lesion group (0-20 points) and severe lesion group (≥81 points). The differences of each index between different coronary lesion degree groups were compared. Lasso regression and Logistic regression were used to analyze the risk factors of aggravating coronary lesion risk in elderly patients with AMI, and then the nomogram prediction model was established for evaluation and external validation.Results:① In the model group, there were significant differences in the family history of coronary heart disease, FBG and HDL-C between the mild lesion group (411 cases) and the severe lesion group (417 cases) [family history of coronary heart disease: 3.6% vs. 7.7%, FBG (mmol/L): 5.88±1.74 vs. 6.43±2.06, HDL-C (mmol/L): 1.48±0.69 vs. 1.28±0.28, all P < 0.05]. In the validation group, there were significant differences between the mild lesion group (153 cases) and the severe lesion group [132 cases; FBG (mmol/L): 5.58±0.88 vs. 6.85±0.79, HDL-C (mmol/L): 1.59±0.32 vs. 1.16±0.21, both P < 0.05]. ② Lasso regression analysis showed that family history of coronary heart disease, FBG, and HDL-C were risk factors of coronary artery disease in elderly patients with AMI, with coefficients 0.118, 0.767, and -0.558, respectively. Logistic regression analysis showed that FBG [odds ratio ( OR) = 1.479, 95% confidence interval (95% CI) was 1.051-2.082, P = 0.025] and HDL-C ( OR = 0.386, 95% CI was 0.270-0.553, P < 0.001] were independent risk factors of coronary artery disease in elderly patients with AMI. ③ According to the rank score of FBG and HDL-C, the nomogram prediction risk model of aggravating coronary artery disease degree was established for each patient. It was concluded that the risk of coronary artery disease in elderly people with higher FBG level and (or) lower HDL-C level was significantly increased. ④ The nomogram model constructed with the model group data predicted the risk concordance index (C-index) was 0.689, and the C-index of the external validation group was 0.709. Conclusions:FBG and HDL-C are independent risk factors for aggravating coronary artery disease in elderly patients with AMI. The nomogram model of aggravating coronary artery disease in elderly patients with AMI has good predictive ability, which can provide more intuitive research methods and clinical value for preventing the aggravation of coronary artery disease in elderly patients.

Objective To develop a observation table with influencing factors for catheter-associated urinary tract infections in critical patients and verify its reliability and validity. Methods Literature review, brainstorming method, expert interview and group discussion were performed to identify items of the form. By convenience sampling method, totally 130 severe patients with urinary catheter were investigated by this scale. This form was evaluated by item analysis, exploratory factor analysis and reliability and validity test. Results The observation table with influencing factors for Catheter-associated Urinary Tract Infections in critical patients consisted of five dimensions and 26 items. The cumulative contribution of variance was 73.752%, the Cronbach′s alpha coefficient was 0.869 and the Spearman-Brown split-half coefficient was 0.828. Regarding to the construct validity, the correlation coefficient between the each factor and total observation table was 0.652~0.873, the correlation coefficient between the factors was 0.311~0.823. All the difference of correlation coefficients were statistically significant (P<0.01). Conclusions The observation table with influencing factors for Catheter-associated Urinary Tract Infections in critical patients has been proved to be reliable and valid. It can be used as a valid tool to assess influencing factors for Catheter-associated Urinary Tract Infections in critical patients.