Objective:To report the nationwide surveillance results of pathogenic profiles and antimicrobial resistance patterns of Gram-positive bloodstream infections in China in 2023.Methods:The clinical isolates of Gram-posttive bacteria from blood cultures were collected in member hospitals of National Bloodstream Infection Bacterial Resistant Investigation Collaborative System（BRICS）during January to December 2023. Antimicrobial susceptibility testing was performed using the dilution method recommended by the Clinical and Laboratory Standards Institute（CLSI）. Statistical analyses were conducted using WHONET 5.6 and SPSS 25.0 software.Results:A total of 4 385 Gram-positive bacterial isolates were obtained from 60 participating center. The top five pathogens were Staphylococcus aureus（ n=1 544，35.2%），coagulase-negative Staphylococci（ n=1 441，32.9%）， Enterococcus faecium（ n=574，13.1%）， Enterococcus faecalis（ n=385，8.8%），and α-hemolytic Streptococci（ n=187，4.3%）. The prevalence of methicillin-resistant Staphylococcus aureus（MRSA）and methicillin-resistant coagulase-negative Staphylococci（MRCNS）was 26.2%（405/1 544）and 69.8%（1 006/1 441），respectively. Notably，all Staphylococci remained susceptible to glycopeptide or daptomycin. Staphylococcus aureus demonstrated excellent susceptibility（>97.0%）to cephalobiol，rifampicin，trimethoprim-sulfamethoxazole，linezolid，minocycline，tigecycline，and eravacycline. No Enterococcus exhibiting resistance to linezolid were detected. Glycopeptide resistance was uncommon but more frequent in Enterococcus faecium（resistance to vancomycin and teicoplanin：both 1.7%）compared to Enterococcus faecalis（both 0.3%）. The detection rates of MRSA and MRCNS exhibited significant regional variations across the country（ χ2=17.674 and 148.650，respectively，both P<0.001）. No vancomycin-resistant Enterococci were detected in central China. Institutional comparison demonstrated higher prevalence of MRSA（ χ2=14.111， P<0.001）and MRCNS（ χ2=4.828， P=0.028）in provincial hospitals than that in municipal hospitals. Socioeconomic analysis identified elevated detection rates of both MRSA（ χ2=18.986， P<0.001）and MRCNS（ χ2=4.477， P=0.034）in less developed regions（per capita GDP

Objective:To report the results of bacterial resistant investigation collaborative system（BRICS）on the distribution and antimicrobial resistance profile of clinical Gram-negative bacteria isolates from bloodstream infections in China in 2023，and provide reference for clinical tretment of bloodstream infections and prevention and control of bacterial resistance.Methods:The clinical isolates of Gram-negative bacteria from blood cultures in member hospitals of BRICS were collected during January 2023 to December 2023. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute（CLSI）. WHONET 5.6 and SPSS 25.0 were used to analyze the data.Results:During the study period，11 492 strains of Gram-negative bacteria were collected from 60 hospitals，of which 10 098（87.9%）were Enterobacterales and 1 394（12.1%）were non-fermentative bacteria. The top 5 bacterial species were Escherichia coli（50.0%）， Klebsiella pneumoniae（26.1%）， Pseudomonas aeruginosa（5.1%）， Acinetobacter baumannii complex（5.0%）and Enterobacter cloacae complex（4.1%）. The ESBL-producing rates in Escherichia coli， Klebsiella pneumoniae and Proteus mirablilis were 46.8%（2 685/5 741），18.3%（549/2 999）and 44.0%（77/175），respectively. The prevalence of carbapenem-resistant Escherichia coli（CREC）and carbapenem-resistant Klebsiella pneumoniae（CRKP）were 1.3%（76/5 741）and 15.0%（450/2 999）；32.9%（25/76）and 78.0%（351/450）of CREC and CRKP were sensitive to ceftazidime/avibactam combination，respectively. 94.7%（72/76）and 90.2%（406/450）of CREC and CRKP were sensitive to aztreonam/avibactam combination. Furthermore，57.9%（44/76）and 79.1%（356/450）were sensitive to imipenem/relebactam combination. The prevalence of carbapenem-resistant Acinetobacter baumannii（CRAB）complex was 64.6%（370/573），while more than 80.0% of CRAB complex was sensitive to tigecycline，eravacycline and polymyxin B. The prevalence of carbapenem-resistant Pseudomonas aeruginosa（CRPA）was 17.0%（99/581）. There were differences in the composition ratio of Gram-negative bacteria in bloodstream infections and the prevalence of important Gram-negative bacteria resistance among different regions in China，with statistically significant differences in the prevalence of CREC，CRKP，CRPA and CRAB complex（ χ2=10.6，28.6，10.8 and 19.3， P<0.05）. The prevalence of ESBL-producing Escherichia coli， CREC，CRAB complex and CRKP were higher in provincial hospitals than those in municipal hospitals（ χ2=12.5，9.8，12.7 and 57.8，all P<0.01）. Conclusions:Gram-negative bacteria are the main pathogens causing bloodstream infections in China，and Escherichia coli is ranked in the top，while the trend of Klebsiella pneumoniae increases continuously with time. CRKP infection shows a slow upward trend，CREC infecton maintains a low prevalence level，and CRAB complex infection continues to exhibit a high prevalence rate. The composition and resistance patterns of pathogens causing bloodstream infections vary to some extent across different regions and levels of hospitals in China.

Objective:To explore the value of quantitative parameters of diffusion weighted imaging (DWI) combined with dynamic enhanced magnetic resonance imaging (DCE-MRI) in predicting the efficacy of neoadjuvant chemotherapy for locally advanced breast cancer (LABC) .Methods:A total of 97 patients with LABC admitted to the hospital from Mar. 2020 to Mar. 2023 were studied and received neoadjuvant chemotherapy to evaluate the therapeutic effect, and DWI and DCE-MRI scans were performed before and after treatment. The difference of DWI and DCE-MRI quantitative parameters before treatment in patients with different therapeutic effects was compared, and the correlation between the difference of DWI and DCE-MRI quantitative parameters and therapeutic effect was analyzed. The predictive value of quantitative parameters of DWI and DCE-MRI before treatment was analyzed. The quantitative parameters of DWI and DCE-MRI in patients with different pathological reactions were compared before treatment, and the quantitative parameters of DWI and DCE-MRI were compared before and after treatment.Results:The apparent diffusion coefficient (ADC) of patients with effective chemotherapy before treatment was higher, but transport constant (Ktrans) , extracellular space volume percentage (Ve) and rate constant (Kep) were lower ( t=5.0, 3.27, 3.55, 3.89, P < 0.05) ; Spearman correlation analysis showed that ADC was positively correlated with chemotherapy efficacy before treatment (r=0.66; P < 0.05) , while Kep, Ve, Ktrans were negatively correlated with it (r=-0.58, -0.47, -0.60; P < 0.05) ; ROC curves showed that the area under the curve (AUC) values of ADC, Kep, Ve and Ktrans in predicting chemotherapy efficacy before treatment were 0.771, 0.797, 0.664 and 0.715, respectively, while the combined AUC value of each indicator was 0.832; Compared with patients with non-significant pathological response, ADC before treatment was higher in patients with significant pathological response, Kep, Ve and Ktrans were lower ( t=4.46, 3.32, 3.60, 3.95, P < 0.05) ; Compared with before treatment, ADC value increased after treatment, while Kep, Ve and Ktrans decreased ( t=8.77, 6.22, 9.34, 10.26, P < 0.05) . Conclusion:Quantitative parameters of DWI and DCE-MRI can reflect the changes in the condition of patients with locally advanced neoadjuvant chemotherapy, and the combination of the two can help to improve the predictive value of chemotherapy efficacy in patients.

Objective:To explore the predictive potential of dual-energy CT (DECT) quantitative parameters in identifying breast cancer molecular subtypes and the expression of the epidermal growth factor receptor (EGFR) .Methods:A cohort of 97 breast cancer patients, treated between Jun. 2022 and Jun. 2024 were selected. The study compared DECT parameters-such as iodine concentration (IC) , normalized iodine concentration (NIC) , spectral curve slope (λ HU) , and effective atomic number (Z eff) in both arterial and venous phases across different molecular subtypes. A multiclass logistic regression model was employed to assess the parameters' value in predicting molecular subtypes, while a binary logistic regression model was used to evaluate their predictive value for EGFR expression. Results:Multiple Logistic regression analysis showed that after adjusting for confounder age and family history, IC ( OR=1.72, 2.78, 3.05) , NIC ( OR=2.52, 1.94, 2.93) , λ HU ( OR=2.08, 2.54, 3.17) and Z eff ( OR=2.03, 2.30, 2.37) at arterial stage were independently correlated with the molecular subtypes of breast cancer ( P<0.05) . Binary logistic regression analysis, adjusted for tumor size and lymph node metastasis, identified arterial phase IC ( OR=3.45) , NIC ( OR=2.73) , λ HU ( OR=2.59) , and Z eff ( OR=1.76) as independent risk factors for EGFR-positive breast cancer ( P<0.05) . Conclusion:DECT quantitative parameters, particularly arterial phase IC, NIC, λ HU, and Zeff, offer valuable insights into the molecular subtyping of breast cancer and EGFR expression, thereby assisting in the development of personalized treatment strategies.

Objective:To explore the value of quantitative parameters of diffusion weighted imaging (DWI) combined with dynamic enhanced magnetic resonance imaging (DCE-MRI) in predicting the efficacy of neoadjuvant chemotherapy for locally advanced breast cancer (LABC) .Methods:A total of 97 patients with LABC admitted to the hospital from Mar. 2020 to Mar. 2023 were studied and received neoadjuvant chemotherapy to evaluate the therapeutic effect, and DWI and DCE-MRI scans were performed before and after treatment. The difference of DWI and DCE-MRI quantitative parameters before treatment in patients with different therapeutic effects was compared, and the correlation between the difference of DWI and DCE-MRI quantitative parameters and therapeutic effect was analyzed. The predictive value of quantitative parameters of DWI and DCE-MRI before treatment was analyzed. The quantitative parameters of DWI and DCE-MRI in patients with different pathological reactions were compared before treatment, and the quantitative parameters of DWI and DCE-MRI were compared before and after treatment.Results:The apparent diffusion coefficient (ADC) of patients with effective chemotherapy before treatment was higher, but transport constant (Ktrans) , extracellular space volume percentage (Ve) and rate constant (Kep) were lower ( t=5.0, 3.27, 3.55, 3.89, P < 0.05) ; Spearman correlation analysis showed that ADC was positively correlated with chemotherapy efficacy before treatment (r=0.66; P < 0.05) , while Kep, Ve, Ktrans were negatively correlated with it (r=-0.58, -0.47, -0.60; P < 0.05) ; ROC curves showed that the area under the curve (AUC) values of ADC, Kep, Ve and Ktrans in predicting chemotherapy efficacy before treatment were 0.771, 0.797, 0.664 and 0.715, respectively, while the combined AUC value of each indicator was 0.832; Compared with patients with non-significant pathological response, ADC before treatment was higher in patients with significant pathological response, Kep, Ve and Ktrans were lower ( t=4.46, 3.32, 3.60, 3.95, P < 0.05) ; Compared with before treatment, ADC value increased after treatment, while Kep, Ve and Ktrans decreased ( t=8.77, 6.22, 9.34, 10.26, P < 0.05) . Conclusion:Quantitative parameters of DWI and DCE-MRI can reflect the changes in the condition of patients with locally advanced neoadjuvant chemotherapy, and the combination of the two can help to improve the predictive value of chemotherapy efficacy in patients.

Objective:To explore the predictive potential of dual-energy CT (DECT) quantitative parameters in identifying breast cancer molecular subtypes and the expression of the epidermal growth factor receptor (EGFR) .Methods:A cohort of 97 breast cancer patients, treated between Jun. 2022 and Jun. 2024 were selected. The study compared DECT parameters-such as iodine concentration (IC) , normalized iodine concentration (NIC) , spectral curve slope (λ HU) , and effective atomic number (Z eff) in both arterial and venous phases across different molecular subtypes. A multiclass logistic regression model was employed to assess the parameters' value in predicting molecular subtypes, while a binary logistic regression model was used to evaluate their predictive value for EGFR expression. Results:Multiple Logistic regression analysis showed that after adjusting for confounder age and family history, IC ( OR=1.72, 2.78, 3.05) , NIC ( OR=2.52, 1.94, 2.93) , λ HU ( OR=2.08, 2.54, 3.17) and Z eff ( OR=2.03, 2.30, 2.37) at arterial stage were independently correlated with the molecular subtypes of breast cancer ( P<0.05) . Binary logistic regression analysis, adjusted for tumor size and lymph node metastasis, identified arterial phase IC ( OR=3.45) , NIC ( OR=2.73) , λ HU ( OR=2.59) , and Z eff ( OR=1.76) as independent risk factors for EGFR-positive breast cancer ( P<0.05) . Conclusion:DECT quantitative parameters, particularly arterial phase IC, NIC, λ HU, and Zeff, offer valuable insights into the molecular subtyping of breast cancer and EGFR expression, thereby assisting in the development of personalized treatment strategies.

Objective:To report the nationwide surveillance results of pathogenic profiles and antimicrobial resistance patterns of Gram-positive bloodstream infections in China in 2023.Methods:The clinical isolates of Gram-posttive bacteria from blood cultures were collected in member hospitals of National Bloodstream Infection Bacterial Resistant Investigation Collaborative System（BRICS）during January to December 2023. Antimicrobial susceptibility testing was performed using the dilution method recommended by the Clinical and Laboratory Standards Institute（CLSI）. Statistical analyses were conducted using WHONET 5.6 and SPSS 25.0 software.Results:A total of 4 385 Gram-positive bacterial isolates were obtained from 60 participating center. The top five pathogens were Staphylococcus aureus（ n=1 544，35.2%），coagulase-negative Staphylococci（ n=1 441，32.9%）， Enterococcus faecium（ n=574，13.1%）， Enterococcus faecalis（ n=385，8.8%），and α-hemolytic Streptococci（ n=187，4.3%）. The prevalence of methicillin-resistant Staphylococcus aureus（MRSA）and methicillin-resistant coagulase-negative Staphylococci（MRCNS）was 26.2%（405/1 544）and 69.8%（1 006/1 441），respectively. Notably，all Staphylococci remained susceptible to glycopeptide or daptomycin. Staphylococcus aureus demonstrated excellent susceptibility（>97.0%）to cephalobiol，rifampicin，trimethoprim-sulfamethoxazole，linezolid，minocycline，tigecycline，and eravacycline. No Enterococcus exhibiting resistance to linezolid were detected. Glycopeptide resistance was uncommon but more frequent in Enterococcus faecium（resistance to vancomycin and teicoplanin：both 1.7%）compared to Enterococcus faecalis（both 0.3%）. The detection rates of MRSA and MRCNS exhibited significant regional variations across the country（ χ2=17.674 and 148.650，respectively，both P<0.001）. No vancomycin-resistant Enterococci were detected in central China. Institutional comparison demonstrated higher prevalence of MRSA（ χ2=14.111， P<0.001）and MRCNS（ χ2=4.828， P=0.028）in provincial hospitals than that in municipal hospitals. Socioeconomic analysis identified elevated detection rates of both MRSA（ χ2=18.986， P<0.001）and MRCNS（ χ2=4.477， P=0.034）in less developed regions（per capita GDP

Objective:To report the results of bacterial resistant investigation collaborative system（BRICS）on the distribution and antimicrobial resistance profile of clinical Gram-negative bacteria isolates from bloodstream infections in China in 2023，and provide reference for clinical tretment of bloodstream infections and prevention and control of bacterial resistance.Methods:The clinical isolates of Gram-negative bacteria from blood cultures in member hospitals of BRICS were collected during January 2023 to December 2023. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute（CLSI）. WHONET 5.6 and SPSS 25.0 were used to analyze the data.Results:During the study period，11 492 strains of Gram-negative bacteria were collected from 60 hospitals，of which 10 098（87.9%）were Enterobacterales and 1 394（12.1%）were non-fermentative bacteria. The top 5 bacterial species were Escherichia coli（50.0%）， Klebsiella pneumoniae（26.1%）， Pseudomonas aeruginosa（5.1%）， Acinetobacter baumannii complex（5.0%）and Enterobacter cloacae complex（4.1%）. The ESBL-producing rates in Escherichia coli， Klebsiella pneumoniae and Proteus mirablilis were 46.8%（2 685/5 741），18.3%（549/2 999）and 44.0%（77/175），respectively. The prevalence of carbapenem-resistant Escherichia coli（CREC）and carbapenem-resistant Klebsiella pneumoniae（CRKP）were 1.3%（76/5 741）and 15.0%（450/2 999）；32.9%（25/76）and 78.0%（351/450）of CREC and CRKP were sensitive to ceftazidime/avibactam combination，respectively. 94.7%（72/76）and 90.2%（406/450）of CREC and CRKP were sensitive to aztreonam/avibactam combination. Furthermore，57.9%（44/76）and 79.1%（356/450）were sensitive to imipenem/relebactam combination. The prevalence of carbapenem-resistant Acinetobacter baumannii（CRAB）complex was 64.6%（370/573），while more than 80.0% of CRAB complex was sensitive to tigecycline，eravacycline and polymyxin B. The prevalence of carbapenem-resistant Pseudomonas aeruginosa（CRPA）was 17.0%（99/581）. There were differences in the composition ratio of Gram-negative bacteria in bloodstream infections and the prevalence of important Gram-negative bacteria resistance among different regions in China，with statistically significant differences in the prevalence of CREC，CRKP，CRPA and CRAB complex（ χ2=10.6，28.6，10.8 and 19.3， P<0.05）. The prevalence of ESBL-producing Escherichia coli， CREC，CRAB complex and CRKP were higher in provincial hospitals than those in municipal hospitals（ χ2=12.5，9.8，12.7 and 57.8，all P<0.01）. Conclusions:Gram-negative bacteria are the main pathogens causing bloodstream infections in China，and Escherichia coli is ranked in the top，while the trend of Klebsiella pneumoniae increases continuously with time. CRKP infection shows a slow upward trend，CREC infecton maintains a low prevalence level，and CRAB complex infection continues to exhibit a high prevalence rate. The composition and resistance patterns of pathogens causing bloodstream infections vary to some extent across different regions and levels of hospitals in China.

Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical Gram-positive bacteria isolates from bloodstream infections in China in 2022.Methods:The clinical isolates of Gram-positive bacteria from blood cultures in member hospitals of National Bloodstream Infection Bacterial Resistant Investigation Collaborative System（BRICS）were collected during January 2022 to December 2022. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute（CLSI）. WHONET 5.6 and SPSS 25.0 software were used to analyze the data.Results:A total of 3 163 strains of Gram-positive pathogens were collected from 51 member units，and the top five bacteria were Staphylococcus aureus（ n=1 147，36.3%），coagulase-negative Staphylococci（ n=928，29.3%）， Enterococcus faecalis（ n=369，11.7%）， Enterococcus faecium（ n=296，9.4%）and alpha-hemolyticus Streptococci（ n=192，6.1%）. The detection rates of methicillin-resistant Staphylococcus aureus（MRSA）and methicillin-resistant coagulase-negative Staphylococci（MRCNS）were 26.4%（303/1 147）and 66.7%（619/928），respectively. No glycopeptide and daptomycin-resistant Staphylococci were detected. The sensitivity rates of Staphylococcus aureus to cefpirome，rifampin，compound sulfamethoxazole，linezolid，minocycline and tigecycline were all >95.0%. Enterococcus faecium was more prevalent than Enterococcus faecalis. The resistance rates of Enterococcus faecium to vancomycin and teicoplanin were both 0.5%（2/369），and no vancomycin-resistant Enterococcus faecium was detected. The detection rate of MRSA in southern China was significantly lower than that in other regions（ χ2=14.578， P=0.002），while the detection rate of MRCNS in northern China was significantly higher than that in other regions（ χ2=15.195， P=0.002）. The detection rates of MRSA and MRCNS in provincial hospitals were higher than those in municipal hospitals（ χ2=13.519 and 12.136， P<0.001）. The detection rates of MRSA and MRCNS in economically more advanced regions（per capita GDP≥92 059 Yuan in 2022）were higher than those in economically less advanced regions（per capita GDP<92 059 Yuan）（ χ2=9.969 and 7.606， P=0.002和0.006）. Conclusions:Among the Gram-positive pathogens causing bloodstream infections in China， Staphylococci is the most common while the MRSA incidence decreases continuously with time；the detection rate of Enterococcus faecium exceeds that of Enterococcus faecalis. The overall prevalence of vancomycin-resistant Enterococci is still at a low level. The composition ratio of Gram-positive pathogens and resistant profiles varies slightly across regions of China，with the prevalence of MRSA and MRCNS being more pronounced in provincial hospitals and areas with a per capita GDP≥92 059 yuan.

Objective To observe and evaluate the protective effect of desflurane post-conditioning on myocardial injury during cardiopulmonary bypass and its influence on patients'postoperative recovery.Methods A total of 200 patients in need of cardiac surgery were selected as the experimental subjects,who were aged from 20 to 65 years old,and divided into ASA Ⅱ-Ⅲ and NYHA Ⅱ-Ⅲ by endotracheal intubation and extracorporeal circulation method under general anesthesia.The patients were randomly divided into desflurane post-treatment group(experi-mental group,group D)and control group(group C)after selection.With the successive opening of the aorta and superior vena cava,group D were given 5%desflurane by inhalation with mechanical ventilation.While group C inhaled pure oxygen without inhaling desflurane.The depth of intraoperative anesthesia was maintained between 40～50 during the operation.Radial artery blood was collected from patients in 24 h before surgery(T0),immediately after intubation(T1),and 1 h(T2),6 h(T3),12 h(T4)and 24 h(T5)after aortic opening to achieve the determi-nation of troponin I(cTnI)and creatine kinase isoenzyme MB(CK-MB).On the premise of obtaining the informed consent of the patient,about 50 mg of right atrial appendage tissue was collected before aortic intubation(T1.5)and 1 hour after aortic opening(T2)to determine the apoptosis rate.Results(1)cTnI in group C at the time of T2,T3,T4 and T5 was apparently higher than group D(P<0.05).(2)CK-MB in group C at the time of T3 was apparently higher than group D(P<0.05).(3)The myocardial tissue results showed that there was a lower apoptosis rate in experimental group at the time of T2(P<0.05).Conclusion Desflurane post-conditioning has a myocardial protec-tive effect during cardiac surgery under cardiopulmonary bypass.