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 investigate the effects of long noncoding RNA(lncRNA)-NRON on apoptosis following myocardial infarc-tion(MI)in mice.Methods The C57BL/6 mice were randomly divided into four groups:sham operation(Sham)group,MI group,MI combined with lncRNA-NRON interference lentivirus(MI+shNRON)group,and MI combined with the negative control(NC)lentivirus(MI+NC)group.The expression of lncRNA-NRON was detected using real-time PCR.In addition,the pathology of the myocardial tissue injury was analyzed using HE staining,the myocardial infarction size was examined using TTC staining,and the extent of apoptosis was assessed using the TUNEL assay,respectively.The RPISeq database was used to predict the probability of interaction between lncR-NA-NRON and the voltage-dependent anionic channel protein(VDAC).The effect of lncRNA-NRON on the expression of VDAC protein was detected using Western blotting.Results The lncRNA-NRON expression was significantly increased in the MI group,and the tar-geted knockdown of lncRNA-NRON resulted in alleviation of the pathological myocardial tissue injury,reduction in the myocardial infarc-tion area,and inhibition of apoptosis.The probability of interaction between lncRNA-NRON and VDAC reached 0.9,indicating a high probability of their association.Additionally,lncRNA-NRON could regulate the protein expression of VDAC.Conclusion Knockdown of lncRNA-NRON could reduce the occurrence of myocardial injury following myocardial infarction.This effect may be attributable to a spe-cific mechanism wherein lncRNA-NRON affects the process of apoptosis by binding to VDAC,consequently suppressing its expression.

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 relationship between intramuscular adipose tissue index (IATI) calculated from computed tomography images at transverse process of the first lumbar and all-cause mortality in maintenance dialysis patients, and to provide a reference for improving the prognosis in these patients.Methods:It was a multicenter retrospective cohort study. The clinical data of patients who received maintenance hemodialysis or peritoneal dialysis treatment from January 1, 2017 to December 31, 2019 in 4 grade Ⅲ hospitals including Zhongda Hospital Affiliated to Southeast University, Taizhou People's Hospital Affiliated to Nanjing Medical University, Affiliated Hospital of Yangzhou University, and the Third Affiliated Hospital of Soochow University were retrospectively collected. IATI was calculated by low attenuation muscle (LAM) density/skeletal muscle density. The receiver-operating characteristic curve was used to determine the optimal cut-off value of IATI, and the patients were divided into high IATI group and low IATI group according to the optimal cut-off value. The differences of baseline clinical data and measurement parameters of the first lumbar level between the two groups were compared. The follow-up ended on December 23, 2022. The endpoint event was defined as all-cause mortality within 3 years. Kaplan-Meier survival curve and log-rank test were used to analyze the survival rates and the differences between the two groups. Multivariate Cox regression analysis models were used to analyze the association between IATI and the risk of all-cause mortality in maintenance dialysis patients. Multivariate logistic regression analysis model was used to analyze the influencing factors of high IATI.Results:A total of 478 patients were eligibly recruited in this study, with age of (53.55±13.19) years old and 319 (66.7%) males, including 365 (76.4%) hemodialysis patients and 113 (23.6%) peritoneal dialysis patients. There were 376 (78.7%) patients in low IATI (<0.42) group and 102 (21.3%) patients in high IATI (≥0.42) group. The proportion of age ≥ 60 years old ( χ2=24.746, P<0.001), proportion of diabetes mellitus ( χ2=5.570, P=0.018), fasting blood glucose ( t=-2.145, P=0.032), LAM density ( t=-3.735, P<0.001), LAM index ( t=-7.072, P<0.001), and LAM area/skeletal muscle area ratio ( Z=-9.630, P<0.001) in high IATI group were all higher than those in low IATI group, while proportion of males ( χ2=11.116, P<0.001), serum albumin ( Z=2.708, P=0.007) and skeletal muscle density ( t=12.380, P<0.001) were lower than those in low IATI group. Kaplan-Meier survival analysis showed that the 3-years overall survival rate of low IATI group was significantly higher than that in high IATI group (Log-rank χ2=19.188, P<0.001). Multivariate Cox regression analysis showed that IATI<0.42 [<0.42/≥0.42, HR(95% CI): 0.50 (0.31-0.83), P=0.007] was an independent protective factor of all-cause mortality, and age ≥60 years old [ HR (95% CI): 2.61 (1.60-4.23), P<0.001], diabetes mellitus [ HR (95% CI): 1.71 (1.06-2.78), P=0.029] and high blood neutrophil/lymphocyte ratio [ HR (95% CI): 1.04 (1.00-1.07), P=0.049] were the independent risk factors of all-cause mortality in maintenance dialysis patients. Stepwise Cox regression analysis showed that IATI<0.42 was still an independent protective factor of all-cause mortality in maintenance dialysis patients [<0.42/≥0.42, HR (95% CI): 0.45 (0.27-0.76), P=0.003]. Multivariate logistic regression analysis showed that low skeletal muscle density [ OR (95% CI): 0.84 (0.81-0.88), P<0.001] and high serum triglyceride [ OR (95% CI): 1.39 (1.07-1.82), P=0.015] were the independent influencing factors of IATI≥0.42. Conclusion:IATI<0.42 of the first lumbar level is an independent protective factor of all-cause mortality in maintenance dialysis patients. Localized myosteatosis within high-quality skeletal muscle may reduce the risk of all-cause mortality in these patients.

Objective:To prepare rabbit polyclonal antibodies against respiratory syncytial virus (RSV) N protein and use them as the detection antibodies to establish a N-ELISA-based method for rapid detection of neutralizing antibodies.Methods:A plasmid of pET30a-N for the expression of RSV N protein was constructed. After purification, the protein was immunized into New Zealand rabbits to prepare polyclonal antibodies, which were used as the detection antibodies. Positive serum samples were diluted and used to neutralize RSV (100 TCID 50/well). Hep-2 cells were inoculated and cultured, and then the cells were fixed with 80% acetone. ELISA was performed to detect RSV N protein in infected cells. When the absorbance value of a well was below the cut-off value, it was regarded as the positive well in the neutralization test. The highest dilution of a positive well serum was the neutralizing antibody titer. After optimizting the antibody dilution, detection time, cell density and the duration of neutralization, the method for neutralizing antibody detection was established based on N-ELISA. The established method was verified by analyzing the influences of different cell generations and edge effects, and calculating the accuracy, repeatability and precision. The correlation between the established method and microneutralization method was analyzed by detecting human RSV IgG-positive serum. Results:The plasmid pET30a-N was successfully constructed, and the expressed N protein showed high purity and good specificity. After the third immunization, the antibody titer in rabbit serum was 1∶51 200, and the antibodies could specifically bind to RSV. The prepared rabbit anti-RSV N polyclonal antibodies had a titer of 1∶51 200, and showed good specificity. The neutralizing antibodies could be detected on day 4 with the established method, and the duration of neutralization was shortened to 30 min. Cell generations and the position of wells in the 96-well plate (edge well and non-edge well) had no significant effect on the method, and the repeatability, precision and accuracy of the method were good. In the detection of 64 RSV IgG-positive human serum samples by the established method and microneutralization method, the correlation coefficient was 0.929 6, indicating a good positive correlation between the two methods.Conclusions:A N-ELISA-based method for rapid neutralizing antibody detection is successfully established, which can be used to evaluate the serum antibody level after RSV vaccination.

Respiratory syncytial virus (RSV) is one of the major pathogens of acute respiratory infections, becoming a huge global burden. Virus-receptor interactions play a key role in the pathogenesis of RSV infection. The distribution of receptors influences the cellular and the tissue tropism of RSV as well as the viral replication and proliferation in the host. However, the RSV receptors are currently unknown, which is one of the reasons that hinders the development of RSV vaccines and therapeutic drugs. In this study, the existing RSV receptors are reviewed with the hope to provide ideas for the research of RSV vaccines and therapeutic drugs.

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.

Lung cancer is the top cause of cancer deaths globally.Advances in immune checkpoint inhibitors(ICIs)have transformed cancer treatment,but their use in lung cancer has led to more side effects.This study examined if past pulmonary tuberculosis(TB)affects ICIs'effectiveness and safety in lung cancer treatment.We reviewed lung cancer patients treated with ICIs at Beijing Chest Hospital from January 2019 to August 2022.We compared outcomes and side effects between patients with and without prior TB.Of 116 patients(40 with TB history,76 without),prior TB didn't reduce treatment effectiveness but did increase severe side effects.Notably,older patients(≥65 years)faced a higher risk of severe side effects.Detailed cases of two patients with severe side effects underscored TB as a risk factor in lung cancer patients receiving ICIs,stressing the need for careful monitoring and personalized care.

Objective:To investigate the study on the diagnostic value of multimodal ultrasound technique for the lesion of extensor carpi ulnaris(ECU)tendon in patients with rheumatoid arthritis(RA).Methods:A total of 175 RA patients who were confirmed by the department of rheumatology of Yantaishan Hospital of Yantai city from December 2021 to January 2023 were selected,and them were included into the RA group.Other 50 patients without RA but with clinical symptoms of wrist were included into the non-RA group,and 50 healthy volunteers were included into the healthy control group.All subjects underwent routine ultrasound and shear wave elastography(SWE)examination on wrist,and then,the characteristics of ultrasound images of wrists and the blood flow distribution of ECU power Doppler ultrasonography(PDUS)were recorded.SWE was used to measure ECU to obtain elastic modulus index(EI)and velocity modulus index(VI).The differences between three groups were compared,and the receiver operating characteristic(ROC)value of RA patients were drawn,so as to confirm the area under curve(AUC)value and optimize cutoff value.Results:There were significant differences in EI and VI of the ECU tendon among three groups(F=61.15,61.28,P<0.05),respectively.The optimal cut-off values of EI and VI were respectively 319.35 kPa and 10.55 m/s in RA patients.In RA patients,age and disease course had significant influences on EI(r=0.19,0.21,P<0.05),and age,disease course,ultrasound score of wrist joint,and grade of power Doppler ultrasonography PDUS of the ECU tendon(ECUPDUS)had significant influences on VI(r=0.19,0.15,-0.16,-0.17,P<0.05).Conclusion:SWE is able to quantitatively and non-invasively assess the stiffness information of the ECU tendon in RA patients.After the supplement of gray-scale ultrasound and PDUS,multimodal ultrasound technique can clearly judge the correlation of the lesions of ECU tendon of RA 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.