Objective To establish a HPLC method for determining thimerosal compounds in eye drops. Methods A gradient HPLC system was used in the quantitative analysis of thimerosal compounds on Shiseido MGII C₁₈ column （4.6 mm×250 mm，5 μm）, using 1% triethylamine solution （pH adjusted to 3.0 with phosphate） as mobile phase A, the methanol as mobile phase B, gradient elution, The column temperature was 40 ℃, the detection wavelength was 222 nm, the flow rate was 1 ml/min and the injection volume was 20 µl. Results The established method had good linearity within the concentration range of 4.3-216.7 μg/ml （r>0.999） for thimerosal, with average recoveries was 102.1%, RSD2.7%. Conclusion This method was simple, accurate and highly specific, and could be used for determination of thimerosal compound in eye drops.

Objective:A gas chromatographic method was established for the determination of alcohol and phenolic bacteriostatic agents(chlorobutanol,phenol,benzyl alcohol,phenethyl alcohol,phenoxyethanol,4-chloro-o-cresol and thymol)in eye drops for related quality control.Methods:A capillary column with(5%phenyl)methylsilox-ane as the fixing solution.The initial temperature was 60℃and keep for 10 min.The temperature was rised to 150℃at a rate of 20℃·min-1 and keep for 3 min,Next,the temperature was rised to 230℃at a rate of 50℃·min-1 and keep for 2 min.The detector temperature was 250℃,the inlet temperature was 200℃,and the detector was FID.Direct injection of 1 μL was used for injection.Results:The were a good linear relationship between peak area and concentration in the concentration range of 0.05-1.0 mg·mL-1(chlorobutanol),0.05-1.0 mg·mL-1(phenol),0.1-2.0 mg·mL-1(benzyl alcohol),0.05-1.0 mg·mL-1(phenethyl alco-hol),0.05-1.0 mg·mL-1(phenoxyethanol),0.03-0.6 mg·mL-1(4-chloro-o-cresol)and 0.01-0.20 mg·mL-1(thymol)(r values were 0.999 7,0.999 6,0.999 5,0.999 5,0.999 5,0.999 5,0.999 5 and 0.999 5 respectively).The average recoveries of seven component were 103.4%,95.2%,98.4%,97.2%,97.9%,100.5%and 93.5%respectively.All meet the requirements of methodological research.According to the method,79 batches of samples were tested for alcohol and phenolic bacteriostatic agents.Chlorobutanol was detected in 8 batches of samples,and no other bacteriostatic agents were detected.Conclusion:This method meets the require-ments for specificity and sensitivity,and is suitable for the confirmation and determination of alcohol and phenolic antibacterial agents in eye drops.It can be used for related quality control.

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 observe the association between afterschool physical exercise and sleep quality among preschool children,and to explore the proper afterschool physical exercise model for better sleep quality.Methods A cross-sectional study was conducted.From Apr to Jun 2024,a total of 1 430 children from three public kindergartens in Minhang district were enrolled to participate in the survey.Parents were invited to complete the basic sociodemographic information,afterschool physical exercise information and the Children's Sleep Habits Questionnaire.One-way ANOVA and linear mixed effects models were used to explore the relationship between afterschool exercise and sleep quality.Results A total of 1 430 questionnaires were sent out and 1 384 were recovered with a recovery rate of 96.78%.Among them 1 366 were valid,with an effective rate of 95.52%.The average age of the children was(5.19±0.87)years old with gender ration of 1.07∶1(male:female).The prevalence of poor sleep quality was 80.60%(regarding a CSHQ total score>41 as cutoff).A one-way ANOVA indicated that time on afterschool physical exercise was significantly associated with sleep duration,Night waking,and sleep onset delay(P<0.05).After adjusting for age,gender,the only child or not,main caregiver,and parental education and occupation,linear mixed effects models showed that engaging in afterschool physical activity for at least 180 mins per week has a statistically significant predictive effect on sleep duration scores(β=-0.50,z=-4.52,95%CI:-0.72,-0.28,P<0.001),night waking scores(β=-0.16,z=-2.34,95%CI:-0.29,-0.02,P=0.020),and sleep onset delay scores(β=-0.14,z=-2.35,95%CI:-0.26,-0.02,P=0.019).Conclusion Afterschool exercise was significantly associated with sleep quality among preschool children in Minhang district of Shanghai.The time≥180 min on afterschool exercise per week in preschool children was significantly positively associated with maintaining sleep duration,reducing night wakings and shortening the latency to fall asleep.The habit of afterschool exercise and the time on afterschool exercise should be emphasized by parents and the society to improve sleep quality among preschool children.

Objective To observe the association between afterschool physical exercise and sleep quality among preschool children,and to explore the proper afterschool physical exercise model for better sleep quality.Methods A cross-sectional study was conducted.From Apr to Jun 2024,a total of 1 430 children from three public kindergartens in Minhang district were enrolled to participate in the survey.Parents were invited to complete the basic sociodemographic information,afterschool physical exercise information and the Children's Sleep Habits Questionnaire.One-way ANOVA and linear mixed effects models were used to explore the relationship between afterschool exercise and sleep quality.Results A total of 1 430 questionnaires were sent out and 1 384 were recovered with a recovery rate of 96.78%.Among them 1 366 were valid,with an effective rate of 95.52%.The average age of the children was(5.19±0.87)years old with gender ration of 1.07∶1(male:female).The prevalence of poor sleep quality was 80.60%(regarding a CSHQ total score>41 as cutoff).A one-way ANOVA indicated that time on afterschool physical exercise was significantly associated with sleep duration,Night waking,and sleep onset delay(P<0.05).After adjusting for age,gender,the only child or not,main caregiver,and parental education and occupation,linear mixed effects models showed that engaging in afterschool physical activity for at least 180 mins per week has a statistically significant predictive effect on sleep duration scores(β=-0.50,z=-4.52,95%CI:-0.72,-0.28,P<0.001),night waking scores(β=-0.16,z=-2.34,95%CI:-0.29,-0.02,P=0.020),and sleep onset delay scores(β=-0.14,z=-2.35,95%CI:-0.26,-0.02,P=0.019).Conclusion Afterschool exercise was significantly associated with sleep quality among preschool children in Minhang district of Shanghai.The time≥180 min on afterschool exercise per week in preschool children was significantly positively associated with maintaining sleep duration,reducing night wakings and shortening the latency to fall asleep.The habit of afterschool exercise and the time on afterschool exercise should be emphasized by parents and the society to improve sleep quality among preschool children.

Objective:A gas chromatographic method was established for the determination of alcohol and phenolic bacteriostatic agents(chlorobutanol,phenol,benzyl alcohol,phenethyl alcohol,phenoxyethanol,4-chloro-o-cresol and thymol)in eye drops for related quality control.Methods:A capillary column with(5%phenyl)methylsilox-ane as the fixing solution.The initial temperature was 60℃and keep for 10 min.The temperature was rised to 150℃at a rate of 20℃·min-1 and keep for 3 min,Next,the temperature was rised to 230℃at a rate of 50℃·min-1 and keep for 2 min.The detector temperature was 250℃,the inlet temperature was 200℃,and the detector was FID.Direct injection of 1 μL was used for injection.Results:The were a good linear relationship between peak area and concentration in the concentration range of 0.05-1.0 mg·mL-1(chlorobutanol),0.05-1.0 mg·mL-1(phenol),0.1-2.0 mg·mL-1(benzyl alcohol),0.05-1.0 mg·mL-1(phenethyl alco-hol),0.05-1.0 mg·mL-1(phenoxyethanol),0.03-0.6 mg·mL-1(4-chloro-o-cresol)and 0.01-0.20 mg·mL-1(thymol)(r values were 0.999 7,0.999 6,0.999 5,0.999 5,0.999 5,0.999 5,0.999 5 and 0.999 5 respectively).The average recoveries of seven component were 103.4%,95.2%,98.4%,97.2%,97.9%,100.5%and 93.5%respectively.All meet the requirements of methodological research.According to the method,79 batches of samples were tested for alcohol and phenolic bacteriostatic agents.Chlorobutanol was detected in 8 batches of samples,and no other bacteriostatic agents were detected.Conclusion:This method meets the require-ments for specificity and sensitivity,and is suitable for the confirmation and determination of alcohol and phenolic antibacterial agents in eye drops.It can be used for related quality control.

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.

Background/Aims: The histological characteristics and natural history of precirrhotic primary biliary cholangitis (PBC) with portal hypertension (PH) are unclear. Our aim was to clarify the prevalence, risk factors, and histological characteristics of precirrhotic PBC patients with PH. Methods: This retrospective study compared the clinical features, histological characteristics, and response to ursodeoxycholic acid (UDCA) between the PH and non-PH groups of precirrhotic PBC patients. Results: Out of 165 precirrhotic PBC patients, 40 (24.2%) also had PH. According to histological stage 1, 2 and 3 disease, 5.3% (1/19), 17.3% (17/98), and 45.8% (22/48) of patients also had PH, respectively. Precirrhotic PBC with PH was significantly positively correlated with bile duct loss, degree of cytokeratin 7 positivity, and degree of fibrosis in the portal area, but significantly negatively correlated with lymphoid follicular aggregation. Compared to the non-PH group, patients in the PH group showed a higher prevalence of obliterative portal venopathy, incomplete septal fibrosis, portal tract abnormalities and non-zonal sinusoidal dilatation (p<0.05). In addition, patients with PH were more likely to present with symptoms of jaundice, ascites, epigastric discomfort, a poorer response to UDCA, and more decompensation events (p<0.05). High alkaline phosphatase levels, low white blood cell counts, high Mayo scores, and high FIB-4 index values were risk factors for precirrhotic PBC with PH. Conclusions Approximately 24.2% of precirrhotic PBC patients have PH, which is histologically related to the injury of bile ducts. High alkaline phosphatase levels, low white blood cell counts, high Mayo scores, and high FIB-4 index values are associated with increased risk of precirrhotic PBC with PH.