Background Bacteria are the most diverse and widely sourced microorganisms in the indoor air of subway stations, where pathogenic bacteria can spread through the air, leading to increased health risks. Objective To understand the status and distribution characteristics of indoor air bacterial pollution in subway stations and compartments in a city of Central South China, and to provide a scientific basis for formulating intervention measures to address indoor air bacteria pollution in subways. Methods Three subway stations and the compartments of trains parking there in a city in Central South China were selected according to passenger flow for synchronous air sampling and monitoring. Temperature, humidity, wind speed, carbon dioxide (CO₂), fine particulate matter (PM_2.5), and inhalable particulate matter (PM₁₀) were measured by direct reading method. In accordance with the requirements of Examination methods for public places-Part 3: Airborne microorganisms (GB/T 18204.3-2013), air samples were collected at a flow rate of 28.3 L·min⁻¹, and total bacterial count was estimated. Bacterial microbial species were identified with a mass spectrometer and pathogenic bacteria were distinguished from non-pathogenic bacteria according to the Catalogue of pathogenic microorganisms transmitted to human beings issued by National Health Commission. Kruskal-Wallis H test was used to compare the subway hygiene indicators in different regions and time periods, and Bonferroni test was used for pairwise comparison. Spearman correlation test was used to evaluate the correlation between CO₂ concentration and total bacterial count. Results The pass rates were 100.0% for airborne total bacteria count, PM_2.5, and PM₁₀ in the subway stations and train compartments, 94.4% for temperature and wind speed, 98.6% for CO₂, but 0% for humidity. The overall median (P₂₅, P₇₅) total bacteria count was 177 (138,262) CFU·m⁻³. Specifically, the total bacteria count was higher in station halls than in platforms, and higher during morning peak hours than during evening peak hours (P<0.05). A total of 874 strains and 82 species were identified by automatic microbial mass spectrometry. The results of identification were all over 9 points, and the predominant bacteria in the air were Micrococcus luteus (52.2%) and Staphylococcus hominis (9.8%). Three pathogens, Acinetobacter baumannii (0.3%), Corynebacterium striatum (0.1%), and Staphylococcus epidermidis bacilli (2.2%) were detected in 23 samples (2.6%), and the associated locations were mainly distributed in train compartments during evening rush hours. Conclusion The total bacteria count in indoor air varies by monitoring sites of subway stations and time periods, and there is a risk of opportunistic bacterial infection. Attention should be paid to cleaning and disinfection during peak passenger flow hours in all areas.

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 investigate the role and prognostic value of matrix metalloproteinase-7(MMP7)in the migration and immune cell infiltration of hepatocellular carcinoma.Methods MMP7_siRNA for downregulating the target gene MMP7 and pMMP7 for upregulating MMP7 were constructed and were used to transfect hepatocellular carcinoma cell line(MHCC97H).RT-qPCR and Western Blot were used to measure the mRNA and protein expression levels of the target gene in cells.Scanning electron microscopy and Transwell assay were used to observe the changes in cell pseudopodia and migration ability,and bioinformatics methods were used to investigate the correlation of MMP7 with immune cells and immune infiltration score in TCGA and TIMER databases in patients with hepatocellular carcinoma,as well as the association between MMP7 and the prognosis of patients with hepatocellular carcinoma.The Spearman method was used for correlation analysis.Sanger Box online tool was used to assess the value of MMP7 in the overall survival curve and disease-specific survival of hepatocellular carcinoma.The Kaplan-Meier method was used to plot survival curves,and the Log-rank test was used for comparison of prognosis between different samples.Results After MHCC97H cells were transfected with MMP7_siRNA or pMMP7,there was a significant reduction or increase in the expression of the target gene MMP7;after downregulation of MMP7,there were significant reductions in the number and length of the pseudopodia,while after MMP7 overexpression,there were significant increases in the number and length of filopodia with radial arrangement.The Transwell chamber assay showed that MMP7_siRNA2 significantly reduced the migration ability of cells(P<0.05),and there was a significant increase in migration ability after pMMP7 transfection.The expression of MMP7 was significantly correlated with B lymphocytes(r=0.37,P<0.05),CD4+T lymphocytes(r=0.40,P<0.05),neutrophils(r=0.49,P<0.05),macrophages(r=0.49,P<0.05),and dendritic cells(r=0.47,P<0.05).In the TCGA database,the patients with hepatocellular carcinoma were divided into MMP7 high expression group with 267 patients and MMP7 low expression group with 146 patients based on overall survival,and the results showed that the MMP7 high expression group had a significantly shorter overall survival time than the MMP7 low expression group(P<0.05);based on the disease-specific survival time,the patients were divided into MMP7 high expression group with 257 patients and MMP7 low expression group with 145 patients,and the analysis showed that the MMP7 high expression group also had a significantly shorter disease-specific survival time than the MMP7 low expression group(P<0.05).Conclusion MMP7 promotes the migration of hepatocellular carcinoma cells and plays a major role in immune cell infiltration,and the expression of MMP7 is also significantly associated with the prognosis of hepatocellular carcinoma.

Objective:Diabetic retinopathy (DR) has been reported as the leading cause of blindness among diabetic adults, which is closely related to poor quality of life and increased burden of disability. This study aimed to aggregate the optimally available evidence on modifiable risks of DR.Methods:Until June 2023, PubMed, Cochrane Library, CNKI, and Wanfang databases were used to retrieve Meta-analysis about various risk factors for DR, and Meta-analysis were analyzed and summarized. R 4.3.2 software was used for each Meta-analytic association to calculate the effect size, 95% CI, heterogeneity, small-study effects, excess significance bias, and 95% prediction intervals. The credibility of significant evidence was graded. Results:We captured 23 eligible papers (72 associations) covering a wide range of medication use, concomitant diseases, daily intervention, biomarkers, lifestyle, and physical measurement index. Among them, higher HbA1c variability ( RR=1.45, 95% CI: 1.26-1.66) and urine microalbumin positive ( OR=2.44, 95% CI: 1.99-2.97) were convincing (grade Ⅰ) evidence, and insulin use ( RR=3.48, 95% CI: 2.14-5.67) was highly suggestive (grade Ⅱ) evidence. Moreover, hypertension ( OR=2.03, 95% CI: 1.06-3.97), poor glycemic control ( OR=4.35, 95% CI: 1.47-12.85), positive macroalbuminuria ( OR=8.42, 95% CI: 3.52-20.15), long sleep duration ( OR=2.05, 95% CI: 1.37-3.05), vitamin D deficiency ( OR=2.02, 95% CI: 1.17-3.50), periodontitis ( OR=4.51, 95% CI: 1.76-11.55) were the main risk factors for DR. Intensive blood pressure intervention ( RR=0.78, 95% CI: 0.65-0.94), dietary control ( OR=0.64, 95% CI: 0.47-0.89) and moderate intensity physical activity ( RR=0.76, 95% CI: 0.59-0.97) yielded significant protective associations with DR. Conclusions:Intensive blood pressure glycemic control, and a healthy lifestyle pattern could reduce the risk of DR. This study provides the evidence to identify high-risk populations and recommends rational treatment options and healthy living interventions.

Objective:This study aims to compare the antiviral treatment similarities and differences in the population covered by the 2024 version of the World Health Organization's (WHO) hepatitis B prevention and treatment guidelines and the current Chinese hepatitis B prevention and treatment guidelines, so as to explore their impact on the indications for antiviral therapy in Chinese patients with chronic hepatitis B (CHB).Methods:The information of patients with chronic hepatitis B virus infection who did not receive antiviral treatment was collected through the registration database of the China Clinical Research Platform for Hepatitis B Elimination. Descriptive statistics were conducted on the demographic, blood, biochemical, and virological levels of patients according to the treatment recommendations of the two versions of the guidelines. The Mann-Whitney U test and χ2 test were used to compare the differences and proportional distribution of the treatment populations covered by the two guidelines. The χ2 test was used to analyze the coverage rate of different antiviral treatment indications.Results:A total of 21,134 CHB patients without antiviral treatment were enrolled. 69.4% of patients met the 2024 versions of the WHO guidelines' recommendations. 85.0% of patients met the current Chinese hepatitis B prevention and treatment guidelines. The WHO guidelines for antiviral therapy indications were met in younger patients with higher levels of ALT, AST, and APRI scores, as well as greater proportion of patients with higher viral loads (P<0.001). The WHO guidelines recommended a cut-off value of APRI>0.5, which raised the proportion of patients on antiviral therapy from 6.6% to 30.9%. 45.7% of patients met the antiviral indications for HBV DNA >2000 IU/ml with abnormal transaminase (ALT>30 U/L for males and ALT>19 U/L for females). The reduced APRI diagnostic cut-off value and ALT treatment threshold had further increased the treatment coverage rate by 91.6% in patients with chronic HBV infection in line with the 2024 versions of WHO guidelines.Conclusion:The reduction of the APRI diagnostic cut-off value and the ALT treatment threshold, based on the current hepatitis B guidelines of China, will further improve the treatment coverage of CHB patients.

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.

Background/Aims: Existing hepatocellular carcinoma (HCC) prediction models are derived mainly from pretreatment or early on-treatment parameters. We reassessed the dynamic changes in the performance of 17 HCC models in patients with chronic hepatitis B (CHB) during long-term antiviral therapy (AVT). Methods: Among 987 CHB patients administered long-term entecavir therapy, 660 patients had 8 years of follow-up data. Model scores were calculated using on-treatment values at 2.5, 3, 3.5, 4, 4.5, and 5 years of AVT to predict threeyear HCC occurrence. Model performance was assessed with the area under the receiver operating curve (AUROC). The original model cutoffs to distinguish different levels of HCC risk were evaluated by the log-rank test. Results: The AUROCs of the 17 HCC models varied from 0.51 to 0.78 when using on-treatment scores from years 2.5 to 5. Models with a cirrhosis variable showed numerically higher AUROCs (pooled at 0.65–0.73 for treated, untreated, or mixed treatment models) than models without (treated or mixed models: 0.61–0.68; untreated models: 0.51–0.59). Stratification into low, intermediate, and high-risk levels using the original cutoff values could no longer reflect the true HCC incidence using scores after 3.5 years of AVT for models without cirrhosis and after 4 years of AVT for models with cirrhosis. Conclusions The performance of existing HCC prediction models, especially models without the cirrhosis variable, decreased in CHB patients on long-term AVT. The optimization of existing models or the development of novel models for better HCC prediction during long-term AVT is warranted.

Lipid Droplets/metabolism* ; Bacteria ; Lipid Metabolism

Objective:To investigate the application effect of the blended teaching model of "pre-class synchronous small private online course (SPOC)+ flipped classroom+post-class knowledge expansion" in the theoretical teaching of biochemistry and molecular biology. Methods:A total of 951 students majoring in clinical medicine, preventive medicine, and pharmacy in the class of 2020 in Qiqihar Medical College were selected as teaching reform research group (experimental group), and their curriculum relied on the self-built massive open online course (MOOC) curriculum and the MOOC resources of Chinese universities to construct a blended teaching model; the reform methods such as small class grouping, case-based learning, and diversified examination were adopted to carry out theoretical flipped teaching activities with cross integration of cases and knowledge points as the main line. A total of 847 students majoring in clinical medicine, preventive medicine, and pharmacy in the class of 2019 were selected as control group, and the traditional teaching method was used for theoretical courses. The courses were evaluated by offline assessment and online assessment, and feedback information was collected through examination scores, questionnaire survey, and online voting. SPSS 20.0 was used for statistical analysis, and the t-test was used for comparison between groups. Results:The experimental group had a significantly higher total score of final examination than the control group [(92.12±3.88) vs. (86.73±5.27), P<0.05]. The questionnaire survey showed that the students in the experimental group showed a relatively high degree of satisfaction with the blended teaching reform, which increased their participation, experiencing, and sharing activities. The students majoring in clinical medicine in the class of 2020 believed that they had established clinical thinking ability (263, 92.61%) and become familiar with the clinical manifestations and pathogenesis of common diseases (262, 92.25%); the students majoring in preventive medicine in the class of 2020 believed that they had increased their awareness of serving the public (151, 93.21%) and developed the ability to teach and guide healthy living (148, 91.36%); the students majoring in pharmacy in the class of 2020 believed that they had mastered the mechanism of action of drugs for disease treatment (138, 93.24%) and understood the importance of rational drug use in clinical practice (135, 91.22%). Conclusion:The blended teaching model realizes student-centered teaching, stimulates the interest and initiative in learning, and improves learning outcome, thereby improving teaching quality to a certain extent.

Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical bacterial isolates from bloodstream infections in China in 2021.Methods:The clinical bacterial strains isolated from blood culture from member hospitals of Blood Bacterial Resistant Investigation Collaborative System (BRICS) were collected during January 2021 to December 2021. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical Laboratory Standards Institute (CLSI). WHONET 5.6 was used to analyze data.Results:During the study period, 11 013 bacterial strains were collected from 51 hospitals, of which 2 782 (25.3%) were Gram-positive bacteria and 8 231 (74.7%) were Gram-negative bacteria. The top 10 bacterial species were Escherichia coli (37.6%), Klebsiella pneumoniae (18.9%), Staphylococcus aureus (9.8%), coagulase-negative Staphylococci (6.3%), Pseudomonas aeruginosa (3.6%), Enterococcus faecium (3.6%), Acinetobacter baumannii (2.8%), Enterococcus faecalis (2.7%), Enterobacter cloacae (2.5%) and Klebsiella spp (2.1%). The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase-negative Staphylococcus aureus were 25.3% and 76.8%, respectively. No glycopeptide- and daptomycin-resistant Staphylococci was detected; more than 95.0% of Staphylococcus aureus were sensitive to ceftobiprole. No vancomycin-resistant Enterococci strains were detected. The rates of extended spectrum B-lactamase (ESBL)-producing isolated in Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis were 49.6%, 25.5% and 39.0%, respectively. The prevalence rates of carbapenem-resistance in Escherichia coli and Klebsiella pneumoniae were 2.2% and 15.8%, respectively; 7.9% of carbapenem-resistant Klebsiella pneumoniae was resistant to ceftazidime/avibactam combination. Ceftobiprole demonstrated excellent activity against non-ESBL-producing Escherichia coli and Klebsiella pneumoniae. Aztreonam/avibactam was highly active against carbapenem-resistant Escherichia coli and Klebsiella pneumoniae. The prevalence rate of carbapenem-resistance in Acinetobacter baumannii was 60.0%, while polymyxin and tigecycline showed good activity against Acinetobacter baumannii (5.5% and 4.5%). The prevalence of carbapenem-resistance in Pseudomonas aeruginosa was 18.9%. Conclusions:The BRICS surveillance results in 2021 shows that the main pathogens of blood stream infection in China are gram-negative bacteria, in which Escherichia coli is the most common. The MRSA incidence shows a further decreasing trend in China and the overall prevalence of vancomycin-resistant Enterococci is low. The prevalence of Carbapenem-resistant Klebsiella pneumoniae is still on a high level, but the trend is downwards.