Objective To elucidate the application scope and delineate the criteria of dobutamine stress echocardiography (DSE) in assessing surgical risk associated with valvular heart diseases in patients presenting with reduced left ventricular ejection fraction (LVEF). Methods This retrospective analysis encompassed data from patients with reduced LVEF (LVEF<40%) who underwent DSE prior to valvular heart surgery at the Valvular Surgery Center of Beijing Anzhen Hospital between May 2016 and September 2024. Patients were stratified based on the terminal dose of dobutamine into two cohorts: a limited dose group [receiving a maximum dobutamine dose of <5 µg/(kg·min) due to concomitant conditions such as suspected atrial thrombus, aortic dilation, or previous myocardial infarction] and a non-limited dose group (where dosage was adjusted to either achieve the maximum positive standard or the maximal dose tolerable by the patient). Within the non-limited dose group, patients were further classified into positive and negative response groups. The positive response post DSE was defined based on the following criteria: LVEF≥55% (the maximum positive standard), LVEF<55% but with a 5% improvement (the minimum positive standard) from resting situation, aortic maximum velocity (AVmax)≥400 cm/s, or mean pressure gradient (meanPG)≥40 mm Hg, latter two applicable only to patients with aortic stenosis. Clinical indicators were compared in the three groups. Results A total of 99 patients were enrolled, aged 35 to 87 years, with an average age of (61.7±10.1) years. The number of males was significantly higher than that of females (3:1). There were 61 (61.6%) patients undergoing aortic valve surgery, 25 (25.3%) undergoing mitral valve surgery, and 13 (13.1%) undergoing combined aortic and mitral valve surgery. Nineteen (19.2%) patients experienced adverse symptoms such as palpitations, head and face numbness, dizziness, chest tightness post DSE. Additionally, new-onset or aggravated ventricular premature ventricular contractions were in 40 (40.4%) patients. All above symptoms and signs resolved minutes after cessation of the test. No severe adverse events necessitating oxygen therapy or emergency intervention occurred. Among the 93 patients in the non-limited dose group, 86 were classified in the positive response group and 7 in the negative response group. The left ventricular end diastolic diameter, left ventricular end systolic diameter, and LVEF in the positive group all showed significant improvement compared to preoperative values, and were also significantly better than those in the negative group (P<0.05). All 7 patients with negative DSE results underwent interventional surgery, which was significantly different from the positive group (36 patients, 41.9%). In the limited dose group (n=6), 4 patients with a positive result or a positive trend on DSE underwent median sternotomy, 2 received interventional treatment due to a negative response. No significant differences in mortality were observed among the groups (P>0.05). Conclusion Dobutamine stress echocardiography significantly contributes to risk stratification in surgical interventions for patients with valvular heart disease complicated by reduced LVEF. It aids in determining optimal timing and methods for surgery. With comprehensive patient evaluation and controlled dobutamine dosing, the application of DSE can be safely expanded.

Objective:To investigate the differences in protein profile expression in serum samples from children with corona virus disease 2019（COVID-19）related encephalopathy and to explore the underlying mechanisms.Methods:From December 1,2022 to January 31,2023,28 children with COVID-19 who were admitted to the Department of Pediatric Intensive Medicine at Shandong Provincial Hospital Affiliated to Shandong First Medical University were collected,including 21 patients with encephalopathy(COVID-19 with encephalopathy group) and seven patients without encephalopathy(COVID-19 without encephalopathy group).Three children from each group were selected for serum proteomic analysis using tandem mass spectrometry labeling proteomics technology.Proteins were considered significantly different if the fold change was >1.2 or <0.8，with P<0.05.Bioinformatics analysis，including Gene Ontology and Kyoto Encyclopedia of Genes and Genomes Pathway Enrichment were performed on differentially expressed proteins.Protein-protein interaction networks were analyzed using the STRING database.Selected proteins were further validated by enzyme-linked immunosorbert assay. Results:A total of 41 differentially expressed proteins were identified between the two groups.Among these，14 proteins were upregulated and 27 proteins were downregulated in COVID-19 patients with encephalopathy compared to those without encephalopathy.Bioinformatics analysis revealed that these proteins were primarily enriched in critical signaling pathways，including complement and coagulation regulation，neutrophil degranulation and activation，and platelet degranulation.Enzyme-linked immunosorbert assay validation confirmed significant differences in key coagulation-regulating proteins(von willebrand factor upregulated，serpin family F member 2 downregulated in COVID-19 patients with encephalopatly）between the two groups.Conclusion:Coagulation dysfunction may play a role in the development of COVID-19 associated encephalopathy in children，providing valuable insights for future research.

Objective To comprehensively evaluate the multidimensional impact of the"Tianjin Experience"of Chest Pain Center(CPC)development on in-hospital mortality,optimization of treatment workflows,and regional coordination of care for patients with acute myocardial infarction(AMI),with the aim of providing scientific evidence to further improve the model and enhance AMI treatment outcomes.Methods This study analyzed data from the"Cardiovascular and Cerebrovascular Acute Events Surveillance System"maintained by the Tianjin Center for Disease Control and Prevention from 2013 to 2024.A segmented regression model was applied to assess the long-term trends in in-hospital mortality from acute myocardial infarction(AMI),with a particular focus on evaluating the impact of the chest pain center program on treatment outcomes.Additionally,supplementary analyses were conducted using surveillance data from the Tianjin Chest Pain Center Quality Control Team between 2017 and 2024.To verify the effectiveness of treatment process optimization,temporal trends in key time-based process indicators were assessed,including Door-in-Door-out(DIDO)time at non-PCI hospitals,Door-to-Wire(D-to-W)time,and First Medical Contact to Wire(FMC-to-W)to wire time.Results According to the data from the Tianjin Center for Disease Control and Prevention,the average 28-day AMI mortality rate in the overall patient population was 9.85％.Between 01/2013 and 12/2014,the mortality rate showed a significant upward trend(P＜0.01),followed by a downward trend from 01/2015 to 12/2024,although the latter did not reach statistical significance(P＞0.05).From 2013 to 2024,a total of 27 633 AMI cases with complete clinical records were collected from Tianjin Chest Hospital,with an average 28-day mortality rate of 4.55％.The mortality rate exhibited a decreasing trend from 01/2013 to 12/2016,with an annual percent change(APC)of-7.56(P＜0.05).From 01/2017 to 12/2024,the trend stabilized,with an APC of 0.39(P＞0.05).Conclusions The development of the CPC system in Tianjin significantly reduced key treatment times and improved the overall efficiency of AMI management.While population-level AMI mortality rates began to decline after 2015,the rate of improvement has slowed,indicating a continued need for optimizing the regional coordinated care system to further enhance patient outcomes.

Objective:To investigate the predictive value of pre-infarction angina(PIA)combined with serum lipo-protein-associated phospholipase A2(Lp-PLA2)for no-reflow during primary percutaneous coronary interven-tion(PCI)in elderly patients with new-onset acute ST-segment elevation myocardial infarction(STEMI).Meth-ods:A total of 189 patients who hospitalized because of acute STEMI and underwent primary PCI within 12h in De-partment of Cardiology,Cangzhou People's Hospital between January 2018 and December 2022 were enrolled.Ac-cording to their TIMI blood flow during PCI,the patients were divided into no reflow group(n=42)and normal re-flow group(n=147).The baseline data were compared between two groups.Multivariate Logistic regression analy-sis was used to analyze the risk factors of no-reflow during PCI.The receiver operating characteristic(ROC)curve was plotted to evaluate the predictive value of PIA and Lp-PLA2 for no-reflow.Results:PI A occurred in 73 cases(38.6％),and no reflow occurred in 42 cases(22.2％)during primary PCI.Compared with patients in normal re-flow group,those in no reflow group had significant higher Lp-PLA2[(341.33±98.32)ng/ml vs.(261.95±75.21)ng/ml]and onset to reperfusion time[(7.02±1.28)h vs.(5.14±1.48)h],and significant lower incidence of PIA(23.8％ vs.42.9％)(P＜0.05 or＜0.01).Multivariate Logistic regression analysis showed that Lp-PLA2(OR=1.528,95％CI 1.028～2.030,P＜0.001),onset to reperfusion time(OR=2.602,95％CI 1.848～3.665,P＜0.001)were independent risk factors for no reflow during PCI in elderly STEMI patients,while PIA was an inde-pendent protective factor(OR=0.261,95％CI 0.101～0.671,P=0.005).The area under ROC curve of Lp-PLA2 combined PIA was 0.863(95％CI 0.806～0.909),which was significantly higher than those of Lp-PLA2[0.733(95％CI 0.664～0.794),Z=2.690,P=0.007]and PIA alone[0.609(95％CI 0.535～0.679),Z=5.657,P＜0.001].Conclusion:Pre-infarction angina has an important protective effect on no-reflow in STEMI patients.High Lp-PLA2 and absence of pre-infarction angina at admission may be good predictors of no-reflow during primary PCI in elderly patients with newly-onset acute STEMI,and it contributes to risk stratification of high risk patients.

Artificial intelligence(AI)has emerged as a cutting-edge technology leading the future and is a key engine for China's development.In the innovation and research of medical devices,AI has provided critical support in the areas of intelligent diagnostic assistance,intelligent therapeutic assis-tance,intelligent monitoring,life support,et al.Ma-chine learning-enabled device software functions(ML-DSFs)have become an essential component of many medical devices.Recently,the United States Food and Drug Administration(FDA)released a draft guidance titled"Marketing Submission Rec-ommendations for a Predetermined Change Con-trol Plan for Artificial Intelligence/Machine Learn-ing(AI/ML)-Enabled Device Software Functions(Draft)."that aimed to provide a forward-looking approach to foster the development of ML medical devices.By supporting iterative updates through modifications,this approach ensures the continu-ous safety and effectiveness of the devices.This guidance represents the latest in regulatory direc-tion and is especially beneficial for enhancing the quality and efficiency of clinical trials for AI prod-ucts.Therefore,we plan to provide a detailed intro-duction and interpretation of the guidance,with the aim of learning from international advanced regulatory concepts and experiences to promote the development of ML-DSFs with more profound international influence.

Objective:To investigate the association of systemic immune-inflammation index(SII)and serum cysta-tin C(CysC)with the severity of acute pulmonary embolism(APE),and their predictive value for prognosis.Meth-ods:A total of 181 patients who were first diagnosed with APE in Cangzhou People's Hospital between January 2018 and January 2023 were retrospectively selected.The severity of APE was determined according to risk stratification criteria for pulmonary embolism,and the patients were divided into low-risk group(n=67),middle-risk group(n=81)and high-risk group(n=33).General clinical data and venous blood neutrophils,platelet and lymphocyte counts,CysC and other indicators were collected,and SII was calculated according to the formula.The relevant in-dicators were compared among three groups,and their correlation with the severity of APE was analyzed by Spearman correlation analysis.According to the prognosis,all APE patients were divided into favorable outcome group(n=129)and unfavorable outcome group(n=52).The general clinical data were compared and multivariate Cox regression analysis was used to study the influencing factors of unfavorable outcome in APE patients.The re-ceiver operating characteristic curve(ROC)was drawn to evaluate the predictive value of SII,CysC and their com-bination for the prognosis of APE patients.Nomogram model for prognosis was constructed.Results:Compared with patients in low-risk group,those in the middle-risk group and the high-risk group had significantly higher levels of serum creatinine,CysC and uric acid(P＜0.05 or＜0.01).The SII in the high-risk group was significant-ly higher than those of middle-risk group and low-risk group(P＜0.001 all).Spearman correlation analysis showed that serum creatinine,CysC,uric acid and SII were significant positively correlated with the severity of APE(r=0.356,0.358,0.233,0.353,P＜0.01 all).Compared with patients in the favorable outcome group,those in the unfavorable outcome group had significantly higher levels of D-dimer,serum creatinine,CysC,uric acid and SII(P＜0.01 all).There was a statistically significant difference in the severity of APE between the two groups(P=0.001).Multivariate Cox regression analysis showed that CysC,SII,and middle or high risk of disease severity were independent risk factors for unfavorable outcome in APE patients(HR=1.001～14.453,P＜0.05 or＜0.01).ROC curve indicated that the AUC of SII,CysC and their combination in predicting unfavorable outcome of APE patients were 0.815(95％CI 0.749～0.881),0.747(95％CI 0.661～0.832)and 0.878(95％CI,0.821～0.936),respectively.The combined AUC of the two was significantly higher than those of SII and CysC alone(Z=-2.234,-3.500,P＜0.05 or＜0.01).Based on the above independent risk factors,the AUC values of the 1-year and 3-year unfavorable outcome nomogram models were 92.9 and 88.2,respectively.The calibration prediction curve and the ideal curve fitted well.The decision curve showed that the model had a good net benefit.Conclusion:SII and CysC are significant positively correlated with the severity of APE and they are independent risk factors for unfavor-able outcome of APE,and the combination of the two indicators has a good predictive value for the prognosis of APE.The nomogram constructed has good accuracy and practicability.

Objective To summarize the changing prevalence of carbapenem resistance in Enterobacterales based on the data of CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021 for improving antimicrobial treatment in clinical practice.Methods Antimicrobial susceptibility testing was performed using a commercial automated susceptibility testing system according to the unified CHINET protocol.The results were interpreted according to the breakpoints of the Clinical & Laboratory Standards Institute(CLSI)M100 31st ed in 2021.Results Over the seven-year period(2015-2021),the overall prevalence of carbapenem-resistant Enterobacterales(CRE)was 9.43％(62 342/661 235).The prevalence of CRE strains in Klebsiella pneumoniae,Citrobacter freundii,and Enterobacter cloacae was 22.38％,9.73％,and 8.47％,respectively.The prevalence of CRE strains in Escherichia coli was 1.99％.A few CRE strains were also identified in Salmonella and Shigella.The CRE strains were mainly isolated from respiratory specimens(44.23±2.80)％,followed by blood(20.88±3.40)％and urine(18.40±3.45)％.Intensive care units(ICUs)were the major source of the CRE strains(27.43±5.20)％.CRE strains were resistant to all the β-lactam antibiotics tested and most non-β-lactam antimicrobial agents.The CRE strains were relatively susceptible to tigecycline and polymyxins with low resistance rates.Conclusions The prevalence of CRE strains was increasing from 2015 to 2021.CRE strains were highly resistant to most of the antibacterial drugs used in clinical practice.Clinicians should prescribe antimicrobial agents rationally.Hospitals should strengthen antibiotic stewardship in key clinical settings such as ICUs,and take effective infection control measures to curb CRE outbreak and epidemic in hospitals.

Objective To characterize the changing species distribution and antibiotic resistance profiles of respiratory isolates in hospitals participating in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Methods Commercial automated antimicrobial susceptibility testing systems and disk diffusion method were used to test the susceptibility of respiratory bacterial isolates to antimicrobial agents following the standardized technical protocol established by the CHINET program.Results A total of 589 746 respiratory isolates were collected from 2015 to 2021.Overall,82.6％of the isolates were Gram-negative bacteria and 17.4％were Gram-positive bacteria.The bacterial isolates from outpatients and inpatients accounted for(6.0±0.9)％and(94.0±0.1)％,respectively.The top microorganisms were Klebsiella spp.,Acinetobacter spp.,Pseudomonas aeruginosa,Staphylococcus aureus,Haemophilus spp.,Stenotrophomonas maltophilia,Escherichia coli,and Streptococcus pneumoniae.Each microorganism was isolated from significantly more males than from females(P＜0.05).The overall prevalence of methicillin-resistant S.aureus(MRSA)was 39.9％.The prevalence of penicillin-resistant S.pneumoniae was 1.4％.The prevalence of extended-spectrum β-lactamase(ESBL)-producing E.coli and K.pneumoniae was 67.8％and 41.3％,respectively.The overall prevalence of carbapenem-resistant E.coli,K.pneumoniae,Enterobacter cloacae,Pseudomonas aeruginosa,and Acinetobacter baumannii was 3.7％,20.8％,9.4％,29.8％,and 73.3％,respectively.The prevalence of β-lactamase was 96.1％in Moraxella catarrhalis and 60.0％in Haemophilus influenzae.The H.influenzae isolates from children(＜18 years)showed significantly higher resistance rates to β-lactam antibiotics than the isolates from adults(P＜0.05).Conclusions Gram-negative bacteria are still predominant in respiratory isolates associated with serious antibiotic resistance.Antimicrobial resistance surveillance should be strengthened in clinical practice to support accurate etiological diagnosis and appropriate antimicrobial therapy based on antimicrobial susceptibility testing results.

Objective:To study the transmission pathways among empirical policy guidance,innovation diffusion,and health demands,providing theoretical references and policy recommendations for local governments to accelerate the establishment of hierarchical medical system.Methods:Based on the public value theory,and employed policy intensity quantification model and mediation effect validation model to elucidate the specific impact mechanisms of policy guidance and innovation diffusion on health demand.Results:The regression coefficient of local government policy guidance on residents'emergency care demand was 0.677,the regression coefficient of local government policy guidance on treatment model innovation diffusion in hospitals was 0.374,and the regression coefficient of treatment model innovation diffusion in hospitals on residents'emergency care demand was 0.689.The mediating effect of treatment model innovation diffusion in hospitals accounted for 38.1%of the total effect.The mediating effect of treatment model innovation diffusion in municipal administrative divisions accounted for 68.6%of the total effect.Conclusions and Suggestions:Local government policy guidance had a significant positive impact on residents'emergency care demand,innovation diffusion played a mediating role between policy guidance and health demand.It is recommended that local governments should pay attention to the guiding role of public policies and improve the intensity of chest pain center policies,should play the role of innovation diffusion intermediaries and to promote treatment model innovation diffusion in hospitals and administrative divisions two paths.

Aim To study the mechanism of adipose mesenchymal stem cell exosomes(ASC-exo)inhibition of fluorescein isothiocyanate(FITC)-induced atopic dermatitis(AD).Methods The mouse age,extrac-tion method,and the concentration of a solution of typeⅠ collagen enzyme and other conditions were compared to study the effects on the morphology and quantity of adipose mesenchymal stem cells(ASCs)after extrac-ted.FITC-induced mouse model in vivo was estab-lished and different doses of ASC-exo were given to measure ear thickness,ear weight and ear scratching times of mice.HE staining was used to observe the pathological changes of ear tissue of mice.The non-toxicity of ASC-exo was detected.IgE,IL-5,IL-13 and other cytokines were detected by ELISA.The gene ex-pressions of TSLP,IL-33,occludin,Claudin-1(CLDN-1)and E-cadherin were detected by RT-qPCR.The protein expression was detected by immunohistochemis-try.Results An efficient method for extracting ASCs was established.Compared with the blank group,mice in the model group showed obvious AD symptoms.Compared with the model group,ASC-exo administra-tion group significantly reduced the number of ear scratches,epidermal thickening,inflammatory cell infil-tration and the secretion of Th2 cytokines IL-5 and IL-13.Meanwhile,ASC-exo administration group signifi-cantly increased the expression of structural proteins CLDN-1 and occludin in epithelial cells and decreased the expression of TSLP and IL-33.Conclusions ASC-exo can significantly improve Th2 skin inflamma-tion in AD mice,and its mechanism may be through in-creasing the expression of tight junction proteins and adhesion link protein in epithelial cells,repairing the skin barrier,and inhibiting the key promoters of allergy TSLP and IL-33.