Objective To estimate the biological dose in a patient who developed radiation dermatitis after a local X-ray exposure incident. Methods Peripheral blood samples, which were used to performed lymphocyte chromosome aberration analysis, were collected from the patient at 54 and 102 days after the last exposure. Biological dose in the patient was estimated using four published X-ray dose-effect calibration curves for chromosomal aberrations. The absorbed dose in the patient was reconstructed using Dolphin′s model and time correction factors. Results The abnormal rates of chromosome aberration at 54 and 102 days after exposure were 1.00% and 0.40%, respectively. Based on the four calibration curves, the estimated local exposure dose at 54 day ranged from 3.59 to 10.51 Gy, and the time-corrected whole-body equivalent dose ranged from 0.27 to 0.87 Gy. The local dose estimated at 102 days ranged from 2.24 to 6.64 Gy, with a time-corrected whole-body equivalent dose of 0.12 to 0.60 Gy, which differed from the day-54 estimates. The biological doses estimated by both methods were lower than the physical dose (29.43 Gy). Conclusion The estimation of local biological dose of patient various in four dose-effect curves selected in this study. Delayed blood sampling will lead to underestimate biological dose. Early blood collection after radiation incidents is critical to ensure accuracy and reliability. Moreover, biological dose reconstruction methods for complex exposure scenarios require further research to improve the accracy of emergency response in radiation accidents.

Objective To explore the feasibility of applying artificial intelligence (AI) technology in chromosomal aberration (CA) analysis for occupational health surveillance of radiation workers and in biological dose estimation during nuclear emergency responses. Methods Peripheral blood samples from healthy volunteers were irradiated in vitro with X-rays and cobalt-60 (⁶⁰Co) γ rays. Chromosome slides were prepared using an automated harvesting and dropping device. The data training and outcome evaluation of CA analysis was performed on the AI software using chromosome images from occupational medical examination of radiation workers from the current lab or chromosome slides from blood samples irradiated with X-rays. The trained AI software was then used to assist in CA analysis and biological dose estimation among occupational medical examination of radiation workers, with results compared with manual reading and actual exposure doses. Results The trained AI software achieved a CA recognition accuracy of 95.11%. In the occupational health examination of radiation workers, the positive CA detection rate using AI + manual review was 2.25% higher than that in manual reviewing alone. The errors in biological dose estimation for ⁶⁰Co γ rays and X-rays using AI + manual review analysis were 11.86% and 7.33%, respectively, both within the acceptable 20.00% error margin. Conclusion AI + manual review can be effectively applied in CA analysis for occupational health examination and biological dose estimation during nuclear emergencies, significantly improving analysis efficiency.

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 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 investigate the significance of auditory brainstem response(ABR)combined with auditory steady-state response(ASSR)for the assessment of mild sensorineural hearing loss in infants.Methods Data from 114 infants with mild sensorineural hearing loss were retrospectively analyzed,and their ABR and ASSR results were collected for rank sum test and correlation analysis.Results In the rank sum test,the difference in thresholds between tone-burst ABR(Tb-ABR)and ASSR at 0.5,1,2,4 kHz was statistically significant(P＜0.05),and they were also correlated at 0.5,1,2,4 kHz(P＜0.05),r=0.613,0.569,0.616,0.71.After grouping by gender and ear,there was a correlation between ABR and ASSR at 0.5,1,2,and 4 kHz,male:r=0.61,0.56,0.671,0.774;female:r=0.581,0.558,0.546,0.608;left ear:r=0.61,0.558,0.576,0.715;right ear:r=0.631,0.581,0.662,0.71.And after grouping by age at diagnosis,only infants diagnosed from 7～12 months of age did not correlate at 0.5 kHz and 1 kHz(P＞0.05),while the rest of the groups had a good correlation(P＜0.05),0～3 months:r=0.686,0.643,0.671,0.742;4～6 months:r=0.671,0.626,0.616,0.693;7～12 months at 2 kHz and 4 kHz:r=0.571,0.706.Conclusion In infants with mild sensorineural hearing loss,ABR and ASSR correlate in assessing hearing thresholds at all frequencies,and the combination of the two tests could provide a more accurate assessment of the subject's true hearing.

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 analyze immune reconstitution and influencing factors in HIV infected men who have sex with men (MSM) with access to antiviral therapy (ART) in Guangxi Zhuang Autonomous Region (Guangxi) during 2005-2021.Methods:The data were collected from Chinese Disease Prevention and Control Information System. The study subjects were HIV infected MSM with access to the initial ART for ≥24 weeks in Guangxi from 2005 to 2021 and HIV RNA lower than the detection limit within 24 months. The proportion of infected MSM who had immune reconstitution after ART was calculated. Cox proportional hazard regression model was used to analyze the influencing factors of immune reconstitution. Software SPSS 24.0 was used for statistical analysis.Results:A total of 3 200 HIV infected MSM were enrolled, in whom 15.56 % (498/3 200) had no immune reconstitution, 14.78% (473/3 200) had moderate immune reconstitution, and the rate of complete immune reconstitution was 69.66% (2 229/3 200). The M ( Q1, Q3) of ART time for immune reconstitution was 12 (5, 27) months. Multivariate Cox proportional risk regression model analysis results showed that compared with those with initial ART at age ≥30 years, WHO clinical stage Ⅲ/Ⅳ illness, baseline BMI <18.50 kg/m 2 and baseline CD4 +T lymphocyte (CD4) counts <200 cells/μl, HIV infected MSM with initial ART at age <30 years, WHO clinical stageⅠ/Ⅱ illness, baseline BMI≥24.00 kg/m 2 and baseline CD4 counts ≥200 cells/μl were more likely to have complete immune reconstitution. Conclusions:In the HIV infected MSM in Guangxi, failures to achieve moderate and complete immune reconstitution were observed. Surveillance and ART regimen should be improved for key populations, such as those with older age and low baseline CD4 counts.

Objective　To understand the impact of early and timely treatment and initial antiviral treatment regimen on mortality and attrition of antiretroviral therapy. Methods A retrospective cohort study was conducted using download data on antiretroviral therapy for HIV-infected patients in Liuzhou City, Guangxi Province, from the database of the Basic Information System for AIDS Control and Prevention (BISAC) from 2010 to 2020. The Cox proportional risk regression model was used to analyze the influencing factors of mortality and attrition. Results A total of 15 713 infected patients were included, including 53.4% aged 18-<50 years, 69.4% male, 61.0% farmer, 75.1% CD4 count <350 cells /μL before initial antiviral treatment, the overall mortality rate was 4.30/100 person-years, and the overall attrition was 2.42/100 person-years. The results of Cox regression analysis showed that the influencing factors of mortality were pretreatment CD4 counts of 350-<500 cells/μL(AHR=0.72, 95%CI: 0.63-0.81) and ≥500 cells/μL (AHR= 0.64, 95%CI: 0.55-0.76); duration from diagnosis to initial antiviral treatment 91-180 days (AHR=1.25, 95%CI: 1.08-1.45), 181-365 days (AHR=1.26, 95%CI: 1.08-1.47), and ≥365 days (AHR=1.26, 95%CI: 1.11-1.44); initial antiviral treatment regimens of D4T+3TC+EFV/NVP (AHR=1.47, 95%CI: 1.32-1.63) and AZT/D4T/TDF+3TC+LPV/r (AHR=1.73, 95%CI: 1.50-1.99). Factors affecting attrition were pretreatment CD4 counts of 350-499 cells/μL (AHR=1.32, 95%CI: 1.16-1.50) and ≥500 cells/μL (AHR=1.28, 95%CI: 1.10-1.50); interval from HIV positivity confirmation to initial dosing ≥365 days (AHR=1.21, 95%CI: 1.04-1.40), initial antiviral treatment regimens of TDF+3TC+NVP (AHR=1.32, 95%CI: 1.13-1.55), AZT+3TC+EFV/NVP (AHR=1.43, 95%CI: 1.26-1.62) and AZT/D4T/TDF+3TC+LPV/r (AHR=1.33, 95CI%: 1.06-1.67). Conclusions　Early and timely treatment and the initial antiviral treatment regimen of TDF+3TC+EFV have good efficacy, but attention should be paid to the high risk of attrition of HIV-infected people with high CD4 count before treatment.