Objective To analyze the main causes and risk factors of unplanned reoperation after liver transplantation. Methods The clinical data of 242 liver transplant recipients in the First Affiliated Hospital of Anhui Medical University from January 2015 to December 2024 were retrospectively analyzed. According to whether unplanned reoperation was performed during the same hospitalization after surgery, the recipients were divided into the reoperation group (n=36) and the non-reoperation group (n=206). The preoperative, intraoperative and postoperative data of the two groups, as well as donor and graft-related data, were compared to analyze the risk factors of unplanned reoperation after liver transplantation and the survival status of the two groups. Results Among the 242 liver transplant recipients, 36 underwent unplanned reoperations, with a total of 54 procedures including various laparotomies, endoscopic and interventional surgeries, among which there were 20 laparotomies, 18 endoscopic surgeries and 16 interventional surgeries. The most common cause of unplanned reoperation was biliary complications (20 times), followed by vascular complications (17 times). Compared with the non-reoperation group, the reoperation group had longer graft cold ischemia time, higher postoperative fatality rate of recipients, longer length of stay in the intensive care unit and postoperative hospital stay, and higher total hospitalization costs (all P<0.05). The incidence of unplanned reoperation was higher in recipients who underwent split liver transplantation (P<0.05). Multivariate analysis showed that intraoperative blood loss ≥1 000 mL, positive culture of graft perfusate and split liver transplantation were independent risk factors for unplanned reoperation (all P<0.05). The postoperative 7-day, 1-month, 3-month and 6-month survival rates of recipients in the reoperation group and the non-reoperation group were 100% vs. 98.1%, 88.9% vs. 94.2%, 69.4% vs. 90.8% and 66.7% vs. 90.8%, respectively, and the postoperative survival rate of recipients in the reoperation group was lower than that in the non-reoperation group (P<0.05). Conclusions The main causes of unplanned reoperation after liver transplantation are biliary complications, vascular complications, abdominal incision infection and intra-abdominal hemorrhage. Intraoperative massive blood loss, positive culture of graft perfusate and split liver transplantation are the risk factors associated with unplanned reoperation after liver transplantation.

To address the issue of reduced signal quality of photoplethysmography caused by local fluctuation,an approach called locally orthogonal weighted polynomial fitting(LOWPF)is proposed for signal smoothing.After determining the positions of the fluctuation sequences using the forward-backward difference XOR method,weighted polynomial fitting is applied to these sequences,and the fitted values are used to replace the fluctuation sequences to achieve signal smoothing.By constructing orthogonal basis functions,the condition number of the coefficient matrix is reduced,and the stability of the equation system solution for higher-order fitting is improved.Simulation results demonstrate that the smoothed signal's XOR smoothness of the proposed method surpasses that of the moving average algorithm and the empirical mode decomposition reconstruction algorithm.The smoothing results on 241 sets of measured PPG signals show that LOWPF achieves an efficiency of smoothness of 89.10%,significantly higher than the 78.05%of empirical mode decomposition and the 59.13%of the 5-point moving average algorithm.LOWPF has promising application prospects for smoothing signals with significant local fluctuations.

Objective:To evaluate the clinical efficacy of methylation sensitive-high resolution melting curve (MS-HRM) detection of IFN-induced protein 44-like (IFI44L) gene methylation in the diagnosis of systemic lupus erythematosus (SLE), as well as the relationship between IFI44L gene markers and the early onset of SLE.Methods:From February 2020 to September 2022, the MS-HRM was used to detect the methylation level of the IFI44L gene in peripheral blood mononuclear cells of 602 SLE patients and 524 other autoimmune disease patients (excluding SLE) from Beijing Peking Union Medical College Hospital, Guangdong Provincial People′s Hospital, and Shenzhen People′s Hospital, totaling 1 126 patients. Compared with the 2012 SLICC criteria, the suspected cases were followed up for 6 months until the onset and clinical diagnosis of SLE were confirmed. The measurement data of normal distribution were expressed as mean±SD, and the consistency analysis was performed using the Kappa consistency test. The clinical diagnostic efficacy indicators were calculated using the receiver operating characteristic (ROC) curve. Results:RR (95% CI) of early suspected cases was 17.06 (9.43, 30.82). The results of IFI44L gene methylation level were in good agreement with the 2012 SLICC criteria, and the sensitivity, specificity and total coincidence rate were 90.53%, 92.56% and 91.47%, respectively. The Kappa value (95% CI) was 0.829(0.796, 0.862) ( P<0.001). The diagnostic efficiency of IFI44L gene methylation level ( Kappa value 0.817) was superior to anti-nuclear antibody, anti-SM antibody and anti-dsDNA antibody ( Kappa value 0.418, 0.216 and 0.440, respectively). The Kappa values (95% CI) of methylation between MS-HRM and pyrosequencing was 0.861(0.806, 0.916), P<0.001. Conclusion:The hypomethylation of IFI44L gene methylation level detected by MS-HRM is closely related to the occurrence and development of SLE, and its diagnostic performance is better than that of three autoantibodies in SLE diagnosis, which can be used for the early diagnosis of SLE.

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.

To address the issue of reduced signal quality of photoplethysmography caused by local fluctuation,an approach called locally orthogonal weighted polynomial fitting(LOWPF)is proposed for signal smoothing.After determining the positions of the fluctuation sequences using the forward-backward difference XOR method,weighted polynomial fitting is applied to these sequences,and the fitted values are used to replace the fluctuation sequences to achieve signal smoothing.By constructing orthogonal basis functions,the condition number of the coefficient matrix is reduced,and the stability of the equation system solution for higher-order fitting is improved.Simulation results demonstrate that the smoothed signal's XOR smoothness of the proposed method surpasses that of the moving average algorithm and the empirical mode decomposition reconstruction algorithm.The smoothing results on 241 sets of measured PPG signals show that LOWPF achieves an efficiency of smoothness of 89.10%,significantly higher than the 78.05%of empirical mode decomposition and the 59.13%of the 5-point moving average algorithm.LOWPF has promising application prospects for smoothing signals with significant local fluctuations.

Objective:To evaluate the clinical efficacy of methylation sensitive-high resolution melting curve (MS-HRM) detection of IFN-induced protein 44-like (IFI44L) gene methylation in the diagnosis of systemic lupus erythematosus (SLE), as well as the relationship between IFI44L gene markers and the early onset of SLE.Methods:From February 2020 to September 2022, the MS-HRM was used to detect the methylation level of the IFI44L gene in peripheral blood mononuclear cells of 602 SLE patients and 524 other autoimmune disease patients (excluding SLE) from Beijing Peking Union Medical College Hospital, Guangdong Provincial People′s Hospital, and Shenzhen People′s Hospital, totaling 1 126 patients. Compared with the 2012 SLICC criteria, the suspected cases were followed up for 6 months until the onset and clinical diagnosis of SLE were confirmed. The measurement data of normal distribution were expressed as mean±SD, and the consistency analysis was performed using the Kappa consistency test. The clinical diagnostic efficacy indicators were calculated using the receiver operating characteristic (ROC) curve. Results:RR (95% CI) of early suspected cases was 17.06 (9.43, 30.82). The results of IFI44L gene methylation level were in good agreement with the 2012 SLICC criteria, and the sensitivity, specificity and total coincidence rate were 90.53%, 92.56% and 91.47%, respectively. The Kappa value (95% CI) was 0.829(0.796, 0.862) ( P<0.001). The diagnostic efficiency of IFI44L gene methylation level ( Kappa value 0.817) was superior to anti-nuclear antibody, anti-SM antibody and anti-dsDNA antibody ( Kappa value 0.418, 0.216 and 0.440, respectively). The Kappa values (95% CI) of methylation between MS-HRM and pyrosequencing was 0.861(0.806, 0.916), P<0.001. Conclusion:The hypomethylation of IFI44L gene methylation level detected by MS-HRM is closely related to the occurrence and development of SLE, and its diagnostic performance is better than that of three autoantibodies in SLE diagnosis, which can be used for the early diagnosis of SLE.

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.

Liquid chromatography-tandem mass spectrometry (LC-MS/MS) technology has the characteristics of high specificity and high throughput, making it rapidly applied and developed in the field of clinical testing. Its application in the monitoring of therapeutic drugs can effectively improve the quantitative accuracy and sensitivity, and formulate a personalized and optimal dosing plan for patients. However, this technology still faces some challenges, and automation, quality control, and quantitative traceability will be the future development direction.