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.

This study investigated the therapeutic effects and mechanisms of medical ozone on sepsis- associated kidney injury (S-AKI) induced by lipopolysaccharide in mice. Using enzyme-linked immunosorbent assay, renal histopathological evaluation, detection of renal function biochemical indicators, immunofluorescence staining, and Western blot analysis, the effects of intraperitoneal injection of ozone on inflammation, coagulation, and renal tissue in mice were systematically detected.The results demonstrated that ozone treatment significantly reduced circulating levels of the specific markers (citrullinated histone H3 and myeloperoxidase-DNA complexes) from neutrophil extracellular traps (NETs) in S-AKI mice, with a suppression on inflammatory and tissue factor expression in renal tissue. Furthermore, ozone effectively improved microcirculation dysfunction, reduced tubular damage and interstitial inflammatory infiltration, thereby alleviating pathological changes of kidneys of S-AKI mice. Mechanistic studies revealed that ozone enhances phagocytic clearance of tissue factor-rich microparticles (TF-MPs) by activating the 5'-monophosphate-activated protein kinase (AMPK) / scavenger receptor (SR)-A1 signaling pathway in macrophages. In Sr-a1-/- mice, renoprotective effect of ozone was completely abolished, confirming the critical role of SR-A1 in this mechanism. In summary, this study demonstrates that medical ozone promotes macrophage clearance of TF-NETs complexes through the AMPK/SR-A1 signaling axis, exerting dual protective effects on mice through anti-inflammatory action and microcirculation improvement, which provides novel intervention targets and therapeutic strategies for S-AKI treatment.

Objective:Conventional myeloid cell staining methodologies were employed to stain splenocytes and peripheral blood cells by fixation and permeabilization and non-fixation and permeabilization methods,respectively,and effects of staining were compared following flow cytometry detection.Methods:Peripheral blood and spleen of three 8-week-old C57 male mice were divided into fixation and permeabilization group and non-fixation and permeabilization group for staining,and flow cytometry was used to detect mean fluorescence intensity(MFI)of each fluorescent antibody and proportion of positive cells.Results:In mouse peripheral blood samples,MFI of 7-AAD-PerCP-Cyanine5.5 and CD147-PE were lower in fixation and permeabilization group than non-fixation and permeabilization group,MFI of F4/80-FITC,MHC Class Ⅱ(I-A/I-E)-APC-R700,Ly-6c-APC-Cy7,CD206-BV421,CD45-BV510,CD11b-BV605,CD11c-BV650 and CD86-BV786 were higher than non-fixation and permeabilization group.Proportions of each immune cell in fixation and permeabilization group and non-fixation and permeabilization group were highly similar.In mouse spleen samples,MFI of antibodies in fixation and permeabilization group were higher than those in non-fixation and permeabilization group,with exception of CD147-PE,which had a lower MFI than non-fixation and permeabilization group;proportions of dendritic cells and Mon/Ly-6clow cells were lower than non-fixation and permeabilization group,whereas proportions of rest myeloid subpopula-tions were higher than non-fixation and permeabilization group.Conclusion:Fixation and permeabilization in peripheral blood cells can improve antibody MFI,but it has little effect on proportion of positive cells.Fixation and permeabilization can enhance antibody MFI in splenocytes,while effect on proportion of each positive cell is more significant.It is advised that when designing staining strate-gies,researchers attempt to choose alternative cell surface antigens for assay or optimize protocols through required pre-experiments in order to acquire stable and dependable results.

Objective:Conventional myeloid cell staining methodologies were employed to stain splenocytes and peripheral blood cells by fixation and permeabilization and non-fixation and permeabilization methods,respectively,and effects of staining were compared following flow cytometry detection.Methods:Peripheral blood and spleen of three 8-week-old C57 male mice were divided into fixation and permeabilization group and non-fixation and permeabilization group for staining,and flow cytometry was used to detect mean fluorescence intensity(MFI)of each fluorescent antibody and proportion of positive cells.Results:In mouse peripheral blood samples,MFI of 7-AAD-PerCP-Cyanine5.5 and CD147-PE were lower in fixation and permeabilization group than non-fixation and permeabilization group,MFI of F4/80-FITC,MHC Class Ⅱ(I-A/I-E)-APC-R700,Ly-6c-APC-Cy7,CD206-BV421,CD45-BV510,CD11b-BV605,CD11c-BV650 and CD86-BV786 were higher than non-fixation and permeabilization group.Proportions of each immune cell in fixation and permeabilization group and non-fixation and permeabilization group were highly similar.In mouse spleen samples,MFI of antibodies in fixation and permeabilization group were higher than those in non-fixation and permeabilization group,with exception of CD147-PE,which had a lower MFI than non-fixation and permeabilization group;proportions of dendritic cells and Mon/Ly-6clow cells were lower than non-fixation and permeabilization group,whereas proportions of rest myeloid subpopula-tions were higher than non-fixation and permeabilization group.Conclusion:Fixation and permeabilization in peripheral blood cells can improve antibody MFI,but it has little effect on proportion of positive cells.Fixation and permeabilization can enhance antibody MFI in splenocytes,while effect on proportion of each positive cell is more significant.It is advised that when designing staining strate-gies,researchers attempt to choose alternative cell surface antigens for assay or optimize protocols through required pre-experiments in order to acquire stable and dependable results.

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.

ObjectiveTo establish an analytical method for the determination of resorcinol, ferulic acid, phenethylresorcinol and benzoyl peroxide in freckle whitening cosmetics by high performance liquid chromatography (HPLC), to provide data support for the establishment of cosmetics inspection methods and technical support for the supervision of the cosmetics industry. MethodsThe analytes in samples were extracted by ultrasonic acetonitrile after methanol vortex, and then filtered by centrifugation and microporous filter membrane. Finally, the analytes were separated with a SVEA C4 column (250 mm×4.6 mm, 5 μm). The mobile phase was composed of 0.1% phosphoric acid solution -acetonitrile, and the gradient elution was applied, with a flow rate of 1.0 mL·min^-1. The samples were detected by an ultra-violet detector and quantified by external standard method. ResultsResorcinol, ferulic acid, phenylethylresorcinol and benzoyl peroxide showed good linearity in the experimental range with r>0.999. HPLC was used to investigate the positive spiked recoveries of ferulic acid or phenylethylresorcinol with different matrices. The results showed that the recoveries were all in the range of 87.48% to 101.00%, and the relative standard deviations were all in the range of 3.4% to 4.1%. Furthermore, HPLC also examined the blank matrix spiked with the recoveries ranged from 93.26% to 107.66%, with the relative standard deviation of 0.90% to 2.90%. The limits of detection ranged from 0.000 8% to 0.002%. Among the30 batches of standard freckle whitening cosmetics determined, 6 batches of which were detected with phenethylresorcinol and 1 batch with ferulic acid. ConclusionHPLC is a method with rapidity, simplicity, and high sensitivity, which is suitable for the simultaneous determination of resorcinol, ferulic acid, phenethylresorcinol and benzoyl peroxide in commercially available cosmetics.

Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical Gram-negative bacteria isolates from bloodstream infections in China in 2022.Methods:The clinical isolates of Gram-negative 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:During the study period，9 035 strains of Gram-negative bacteria were collected from 51 hospitals，of which 7 895（87.4%）were Enterobacteriaceae and 1 140（12.6%）were non-fermenting bacteria. The top 5 bacterial species were Escherichia coli（ n=4 510，49.9%）， Klebsiella pneumoniae（ n=2 340，25.9%）， Pseudomonas aeruginosa（ n=534，5.9%）， Acinetobacter baumannii complex（ n=405，4.5%）and Enterobacter cloacae（ n=327，3.6%）. The ESBLs-producing rates in Escherichia coli， Klebsiella pneumoniae and Proteus spp. were 47.1%（2 095/4 452），21.0%（427/2 033）and 41.1%（58/141），respectively. The prevalence of carbapenem-resistant Escherichia coli（CREC）and carbapenem-resistant Klebsiella pneumoniae（CRKP）were 1.3%（58/4 510）and 13.1%（307/2 340）；62.1%（36/58）and 9.8%（30/307）of CREC and CRKP were resistant to ceftazidime/avibactam combination，respectively. The prevalence of carbapenem-resistant Acinetobacter baumannii（CRAB）complex was 59.5%（241/405），while less than 5% of Acinetobacter baumannii complex was resistant to tigecycline and polymyxin B. The prevalence of carbapenem-resistant Pseudomonas aeruginosa（CRPA）was 18.4%（98/534）. There were differences in the composition ratio of Gram-negative bacteria in bloodstream infections and the prevalence of main Gram-negative bacteria resistance among different regions，with statistically significant differences in the prevalence of CRKP and CRPA（ χ2=20.489 and 20.252， P<0.001）. The prevalence of CREC，CRKP，CRPA，CRAB，ESBLs-producing Escherichia coli and Klebsiella pneumoniae were higher in provinicial hospitals than those in municipal hospitals（ χ2=11.953，81.183，10.404，5.915，12.415 and 6.459， P<0.01 or <0.05），while the prevalence of CRPA was higher in economically developed regions（per capita GDP ≥ 92 059 Yuan）than that in economically less-developed regions（per capita GDP <92 059 Yuan）（ χ2=6.240， P=0.012）. Conclusions:The proportion of Gram-negative bacteria in bloodstream infections shows an increasing trend，and Escherichia coli is ranked in the top，while the trend of CRKP decreases continuously with time. Decreasing trends are noted in ESBLs-producing Escherichia coli and Klebsiella pneumoniae. Low prevalence of carbapenem resistance in Escherichia coli and high prevalence in CRAB complex have been observed. The composition ratio and antibacterial spectrum of bloodstream infections in different regions of China are slightly different，and the proportion of main drug resistant bacteria in provincial hospitals is higher than those in municipal hospitals.

Objective To explore the public's cognition and attitude towards general medicine,general practitioners,and pre-hospital first-aid knowledge in Ludian County,Yunnan Province,to find out the training and learning methods that are more acceptable to the public for this kind of related knowledge,and to propose targeted solutions.Methods A complete random sampling survey was conducted among the nucleic acid collection office at the gate of the vegetable market from October 15,2022,to December 30,2022,and the outpatient clinic of Wenping Street Health Center from January 1,2023,to February 28,2023,by using electronic questionnaire and paper questionnaire.Results Nearly 50%of the people in Ludian County of Yunnan Province lack the knowledge of general medicine and pre-hospital emergency care,especially the knowledge of electrical defibrillation.People with higher education and the medical profession have a higher understanding of general medicine,and people with a higher understanding of general medicine are more willing to participate in pre-hospital emergency care.The average Ridit value is:very familiar with general medicine(0.774)>Knowledge of some general practices(0.565)>Never heard of general practice(0.400).The higher education level and the more comprehensive understanding of general medicine had a positive impact on participation in pre-hospital emergency care,with B values of 0.624 and 0.619,OR 95%CI of 1.867(1.544～2.257)and 1.857(1.298～2.657),respectively.Taking medical staff as a reference,the B value of medical students was = 0.942,P = 0.234,the difference was not significant,and the B value of non-medical professional population was all less than 0,the effect is negative.In addition,most people have a positive attitude towards learning pre-hospital first aid,and more than 70%of people are willing to learn and train related knowledge of pre-hospital first aid.Conclusions People in urban areas of Ludian County,Yunnan Province have poor understanding of general practice,low recognition of general practitioners,low demand for general practitioners,and lack of awareness of the importance of pre-hospital emergency treatment.Because of the cognitive differences among different groups,it is necessary to conduct specific training for different groups.