Objective:To investigate the effect of laparoscopic splenectomy and azygoportal disconnection (LSD) on liver synthesis and development of liver cirrhosis.Methods:This is a prospective case series study.The clinical data of liver cirrhotic patients with portal hypertension who received LSD at the Department of Hepatobiliary Surgery of Northern Jiangsu People′s Hospital Affiliated to Yangzhou University from September 2014 to January 2016 were included. This study analyzed the diameter of the portal vein, the velocity of portal blood flow, the routine blood parameters, the liver function, the synthetic proteins of liver (antithrombin Ⅲ (AT-Ⅲ), protein S, protein C), and the serum content of liver fibrotic markers(collagen type Ⅳ, procollagen type Ⅲ, laminin, hyaluronidase). Repeated measures ANOVA was used for comparison between multiple groups, and least significance difference was used for post-hoc multiple comparison.Results:A total of 106 patients were included in the study, including 70 males and 36 females, aged (51.8±9.8) years(range: 28 to 75 years).Compared with the preoperative results, the diameter of portal vein and the velocity of portal vein decreased after surgery ( F=14.03, 12.15, respectively, both P<0.01). Compared with the preoperative results, the total bilirubin, albumin, prothrombin time, international normalized ratio, Child-Pugh score and classification were improved ( F=17.96, 56.01, 66.63, 35.83, 33.49, and 27.50, respectively, all P<0.01), and the AT-Ⅲ, protein S, protein C,collagen type Ⅳ, procollagen type Ⅲ, laminin and hyaluronidase levels were also improved ( F=47.87, 36.26, 18.02, 2.79, 14.58, 44.35, and 14.38, respectively, all P<0.01). Compared with the preoperative period, the diameter of portal vein was reduced from the first week to the 24 th month after surgery ( t=5.45 to 9.39, all P<0.01). Compared with the preoperative period, the velocity of portal vein blood from the first week after surgery to the 24 th month after surgery was decreased ( t=4.02 to 8.43, all P<0.01). Compared with the preoperative period, routine blood parameters (white blood count, hemoglobin, platelet count), liver function (total bilirubin, albumin, prothrombin time, international normalized ratio, Child-Pugh score), liver synthetic protein (AT-Ⅲ, protein S, protein C) and liver fibrotic markers (collagen type Ⅳ, procollagen type Ⅲ, laminin, hyaluronidase) were improved to varying degrees at the 24th month after surgery ( t=-20.46 to 11.93, all P<0.01). Conclusion:Preliminary findings show that LSD can reduce portal vein pressure, restore blood cell number, and improve liver synthesis function and the degree of liver fibrosis in patients with portal hypertension in liver cirrhosis.

Objective:To investigate the effect of laparoscopic splenectomy and azygoportal disconnection (LSD) on liver synthesis and development of liver cirrhosis.Methods:This is a prospective case series study.The clinical data of liver cirrhotic patients with portal hypertension who received LSD at the Department of Hepatobiliary Surgery of Northern Jiangsu People′s Hospital Affiliated to Yangzhou University from September 2014 to January 2016 were included. This study analyzed the diameter of the portal vein, the velocity of portal blood flow, the routine blood parameters, the liver function, the synthetic proteins of liver (antithrombin Ⅲ (AT-Ⅲ), protein S, protein C), and the serum content of liver fibrotic markers(collagen type Ⅳ, procollagen type Ⅲ, laminin, hyaluronidase). Repeated measures ANOVA was used for comparison between multiple groups, and least significance difference was used for post-hoc multiple comparison.Results:A total of 106 patients were included in the study, including 70 males and 36 females, aged (51.8±9.8) years(range: 28 to 75 years).Compared with the preoperative results, the diameter of portal vein and the velocity of portal vein decreased after surgery ( F=14.03, 12.15, respectively, both P<0.01). Compared with the preoperative results, the total bilirubin, albumin, prothrombin time, international normalized ratio, Child-Pugh score and classification were improved ( F=17.96, 56.01, 66.63, 35.83, 33.49, and 27.50, respectively, all P<0.01), and the AT-Ⅲ, protein S, protein C,collagen type Ⅳ, procollagen type Ⅲ, laminin and hyaluronidase levels were also improved ( F=47.87, 36.26, 18.02, 2.79, 14.58, 44.35, and 14.38, respectively, all P<0.01). Compared with the preoperative period, the diameter of portal vein was reduced from the first week to the 24 th month after surgery ( t=5.45 to 9.39, all P<0.01). Compared with the preoperative period, the velocity of portal vein blood from the first week after surgery to the 24 th month after surgery was decreased ( t=4.02 to 8.43, all P<0.01). Compared with the preoperative period, routine blood parameters (white blood count, hemoglobin, platelet count), liver function (total bilirubin, albumin, prothrombin time, international normalized ratio, Child-Pugh score), liver synthetic protein (AT-Ⅲ, protein S, protein C) and liver fibrotic markers (collagen type Ⅳ, procollagen type Ⅲ, laminin, hyaluronidase) were improved to varying degrees at the 24th month after surgery ( t=-20.46 to 11.93, all P<0.01). Conclusion:Preliminary findings show that LSD can reduce portal vein pressure, restore blood cell number, and improve liver synthesis function and the degree of liver fibrosis in patients with portal hypertension in liver cirrhosis.

Background::B-cell maturation antigen (BCMA)-directed chimeric antigen receptor T (CAR-T) therapy yield remarkable responses in patients with relapsed/refractory multiple myeloma (R/RMM). Circulating tumor DNA (ctDNA) reportedly exhibits distinct advantages in addressing the challenges posed by tumor heterogeneity in the distribution and genetic variations in R/RMM.Methods::Herein, the ctDNA of 108 peripheral blood plasma samples from patients with R/RMM at the First Affiliated Hospital, School of Medicine, Zhejiang University was thoroughly investigated before administration of anti-BCMA CAR-T therapy to establish its predictive potential. Flow cytometry is used primarily to detect subgroups of T cells or CAR-T cells.Results::In this study, several tumor and T cell effector-mediated factors were considered to be related to treatment failure by an integrat analysis, including higher percentages of multiple myeloma (MM) cells in the bone marrow ( P = 0.0125), lower percentages of CAR-T cells in the peripheral blood at peak ( P = 0.0375), and higher percentages of CD8 + T cells ( P = 0.0340). Furthermore, there is a substantial correlation between high ctDNA level (>143 ng/mL) and shorter progression-free survival (PFS) ( P = 0.007). Multivariate Cox regression analysis showed that high levels of ctDNA (>143 ng/mL), MM-driven high-risk mutations (including IGLL5 [ P = 0.004], IRF4 [ P = 0.024], and CREBBP [ P = 0.041]), number of multisite mutations, and resistance-related mutation ( ERBB4, P = 0.040) were independent risk factors for PFS. Conclusion::Finally, a ctDNA-based risk model was built based on the above independent risk factors, which serves as an adjunct non-invasive measure of substantial tumor burden and a prognostic genetic feature that can assist in predicting the response to anti-BCMA CAR-T therapy.

Objective To compare the stress magnitude and distribution of the restorations,remaining tooth tissues,and bonding interfaces of endodontically mandibular first molar with different buccolingual residual tooth tissue thicknesses in two different restorations.Methods The finite element method was used to model the restorations of mandibular first molars with different buccolingual residual tissue thicknesses after root canal treatment.The vertical and oblique loads were applied to record the stress magnitude and distribution of restorations,residual tissues,and bonding interfaces of the different restorations.Results Three different models of mandibular first molar were designed based on the amount of buccal and glossal side dental tissue.Based on this simulation of the dental preparation of FO and EC and the preparation of the prosthesis,generating 6 different groups:FO repair in A1 group,thickness of the buccal tooth tissue is 2mm;A2 group was repaired by FO,thickness of the buccal tooth tissue is 3mm;A3 Group was performed with FO repair,thickness of the buccal and lingual remaining tooth tissue is 4mm;In B1 group,with EC repair,thickness of buccal tooth tissue is 2mm;In B2 group with EC repair,thickness of buccal tooth tissue is 3mm;In B3 group,using EC repair,thickness of remaining dental tissue on buccal and lingual side was 4mm.Results Two loading modes,the restoration such as effect force distribution are concentrated around the loading point,dentin effect force are concentrated in the tooth neck,the full coverage of high embedded group restoration-dental resin interface maximum main stress(MPS)is concentrated in the hole wall and shaft wall Angle,the pulp cavity setting crown group restoration-dental resin interface MPS focus in the bottom wall angle of the pulp cavity setting hole type.In the model of tooth tissue thickness in the same buccal-lingual side,except that the peak effect force of the restoration was greater than the peak of the full coverage crown,the peak of the observed index of the full coverage crown was greater than that of the whole cavity.Conclusion Endocrown can better protect the tooth tissue after root canal treatment,and it is recommended to choose endocrown for restoration after root canal treatment.

Objective: To investigate the abnormal fluctuation of coagulation function indicators in pediatric Burkitt lymphoma patients, and to analyze its correlation with disease progression and prognosis. Methods: The data of 172 children with Burkitt lymphoma in Children's Medical Center, Shanghai Jiao Tong University School of Medicine from January 2020 to December 2023 were retrospectively analyzed, and 120 healthy children were used as control group. Plasma prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT), fibrinogen (Fib), International standardized ratio (INR), D-dimer (D-D), fibrinogen degradation products (FDP), and antithrombin (AT) were measured. Appropriate statistical methods were used to compare the data between two groups, and the Cox regression model was employed to analyze the influencing factors. A P-value <0.05 was considered statistically significant. Results: Levels of D-D, FDP, INR, and PT were significantly higher in children with Burkitt lymphoma than in the healthy controls [median (P25, P75) for the case group: 0.35 (0.13, 1.22), 3.10 (1.30, 10.20), 1.16 (1.06, 1.24), 12.60 (11.43, 13.50); median (P25, P75) for the healthy control group: 0.10 (0.07, 0.15), 0.60 (0.20, 1.08), 1.06 (1.02, 1.13), 11.50 (11.00, 12.30)](P<0.05). Levels of D-D, FDP, INR, PT, and TT were significantly elevated in children with recurrence compared to those without recurrence [median (P25, P75) for the recurrent group: 0.44 (0.16, 1.42), 3.85 (1.50, 12.25), 1.17 (1.08, 1.24), 12.70 (11.73, 13.50), 16.20 (14.80, 17.80); median (P25, P75) for the non-recurrent group: 0.21 (0.11, 0.69), 2.00 (1.00, 6.85), 1.11 (1.03, 1.24), 11.90 (11.10, 13.43), 15.20 (14.50, 16.40)](P<0.05). Levels of D-D, FDP in children with metastasis were significantly higher than those without metastasis [median (P25, P75) for the metastatic group: 0.51 (0.17, 1.84), 4.38 (1.70, 13.45); median (P25, P75) for the non-metastatic group: 0.20 (0.11, 0.39), 1.50 (1.00, 3.10)] (P<0.05). Levels of D-D and FDP were significantly higher in children with advanced stage than in those with early stage [median (P25, P75) for the high-stage group: 0.33 (0.14, 1.20), 3.10 (1.40, 10.23); median (P25, P75) for the low-stage group: 0.12 (0.08, 0.24), 0.90 (0.50, 2.50)] (P<0.05). Levels of D-D and FDP in high-risk children were significantly higher than those of low-risk [median (P25, P75) for the high-risk group: 0.28 (0.13, 1.01), 2.90 (1.15, 9.65); median (P25, P75) for the low-risk group: 0.12 (0.08, 0.17), 0.80 (0.43, 1.98)] (P<0.05). Levels of D-D, FDP, INR, and PT were significantly higher in children with poor prognosis than in those with favorable prognosis [median (P25, P75) for the poor prognosis group: 1.76 (0.80, 2.72), 13.45 (7.20, 25.30), 1.19 (1.12, 1.32), 12.85 (12.10, 14.35); median (P25, P75) for the favorable prognosis group: 0.23 (0.12, 0.52), 2.00 (1.00, 4.80), 1.14 (1.05, 1.23), 12.30 (11.40, 13.40)] (P<0.05). INR levels significantly increased with accumulating chemotherapy cycles [median (P25, P75) for one session: 1.09 (1.02, 1.20); two sessions: 1.31 (1.23, 1.38); three sessions: 1.79 (1.52, 2.41)] (P<0.05). Age, APTT, D-D, FDP, INR, PT, recurrence and metastasis had a significant effect on the survival of children with Burkitt lymphoma (P<0.05). Conclusion: Patients with Burkitt lymphoma exhibit coagulation disorders, which are influenced by recurrence, metastasis, clinical stage, risk stratification, and prognosis. In clinical practice, it is crucial to prioritize the monitoring of coagulation indicators to facilitate timely detection of coagulation dysfunction.

Paraplegia caused by spinal cord injury is a serious neurological complication, for which surgery is currently the main treatment method. Due to different surgical approaches, patients are usually expected to maintain a passive prone position for a long time or switch between the supine and prone positions. Affected by multiple factors such as neurogenic sensory disorders, pathological changes in muscle tone and operative duration, the risk of intraoperative acquired pressure injury (IAPI) is significantly increased. Current clinical prevention strategies for IAPI in these patients predominantly focus on localized pressure relief during positioning, lacking systematic, standardized comprehensive prevention protocols or evidence-based guidelines. To address it, Department of Nursing, Orthopedics Branch, China International Exchange and Promotive Association for Medical and Health Care, Spinal Trauma Professional Committee, Orthopedics Branch, Chinese Medical Doctor Association, Nursing Group of Spine and Spinal Cord Professional Committee of Chinese Association of Rehabilitation Medicine organized experts in relevant fields to formulate Guideline for the prevention of intraoperative acquired pressure injury in paraplegic patients with spinal cord injury ( version 2025), based on evidence-based medical evidence and latest research results and clinical practice at home and abroad. Eleven recommendations were put forward from the aspects of preoperative risk assessment, intraoperative prevention strategies, postoperative handover and monitoring, and supportive mechanisms for IAPI prevention, aiming to standardize the prevention measures and management strategies of IAPI in paraplegic patients with spinal cord injury and accelerate the recovery of patients and improve the therapeutic effect.

Objective:To understand the pathogen distribution characteristics of acute lower respiratory tract infections (ALRTI) in hospitalized children in the Department of Respiratory Medicine, Capital Center for Chlidren's Health, Capital Medical University from 2019 to 2023, and to analyze their epidemiological features.Methods:A retrospective analysis was conducted, including 5 558 children aged 0-18 years who were hospitalized and diagnosed with ALRTI in the respiratory department of Capital Center for Chlidren's Health, Capital Medical University from December 8, 2019, to December 31, 2023. Nasopharyngeal swabs, sputum, and bronchoalveolar lavage fluid specimens were collected for pathogen detection.Results:Among the 5 558 ALRTI hospitalized children, the positive detection rate of pathogens was 81.81% (4 547/5 558). In bronchoalveolar lavage fluid specimens, Mycoplasma pneumoniae had the highest detection rate (33.52%), while Streptococcus pneumoniae had the highest detection rate (24.38%) in upper respiratory tract specimens. Mycoplasma pneumoniae (54.21%, χ2=1 034.58, P<0.001) and adenovirus (5.09%, χ2=10.84, P=0.013) were most common in school-age children, human rhinovirus was more common in toddlers (26.42%, χ2=122.36, P<0.001), and respiratory syncytial virus had the highest infection rate in infants (28.61%, χ2=326.47, P<0.001). A total of 52.06% of the children had mixed infections (2 367/4 547), with the highest proportion of mixed infections in infants (62.54%). During the post- non-pharmaceutical interventions (NPIs) period, the proportions of Mycoplasma pneumoniae (69.88% vs. 58.16%), human rhinovirus (30.37% vs. 14.02%), adenovirus (51.16% vs. 6.45%), influenza A virus (36.46% vs. 16.67%), and mixed infections (33.33% vs. 19.04%) in school-age children were significantly higher than during the NPIs period. In contrast, the proportions of respiratory syncytial virus (33.19% vs. 19.42%), adenovirus (11.29% vs. 4.65%), and mixed infections (17.75% vs. 10.89%) in infants were significantly lower than during the NPIs period. Conclusion:NPIs have changed the detection rate and epidemiology of respiratory pathogens in hospitalized children. After the end of NPIs, outbreaks of some pathogens may occur, so it is necessary to strengthen rapid pathogen detection, population surveillance, and health education.

Objective:To analyze the molecular characteristics of prevalent Bordetella pertussis (Bp) isolates in Liaocheng City, Shandong Province in 2024. Methods:From March to August 2024, oropharyngeal swabs were collected from suspected pertussis cases at Liaocheng People′s Hospital in Shandong Province for Bp isolation. A total of 99 Bp isolates were obtained. Whole-genome sequencing was performed on all isolates, followed by Multilocus Sequence Typing (MLST), vaccine antigen-related gene typing (including ptxP, ptxA, ptxB, ptxC, ptxD, ptxE, fhaB, fim2, fim3, and prn), 23S rRNA gene typing, and phylogenetic analysis. To capture the differences between Bp isolates and vaccine strains in Liaocheng City, the international vaccine strain Tohama I and the Chinese vaccine strain CS were included in the analysis. Antimicrobial resistance testing against 11 agents was performed on 52 isolates. Results:The throat swabs of 99 Bp isolates were collected from patients aged 44 days to 42 years, and the median age of the patients was 7 (5, 8) years. All isolates ptxP were ptxP3 type. 74 isolates (74.75%) carried the prn150, while 21 isolates (21.21%) were prn-deficient. The predominant antigenic profile was ptxP3/ ptxA1/ ptxB1/ ptxC4/ ptxD1/ ptxE4/ fhaB1/ fim2-1/ fim3-1/ prn150, found in 72 isolates (72.73%). All 99 isolates carried the A2047G mutation in the 23S rRNA gene. Antimicrobial susceptibility testing showed that the MICs of macrolides and clindamycin for all 52 Bp isolates were all >256 mg/L. However, the isolates showed low MIC for seven other antimicrobials tested, including trimethoprim-sulfamethoxazole, amoxicillin, and levofloxacin. MLST typing revealed that 94 isolates (94.95%) were identified as ST-2, while 5 isolates (5.05%) belonged to a novel sequence type (ST-118). Phylogenetic analysis demonstrated that all 99 Bp isolates were highly homologous but clustered in evolutionary branches distinct from vaccine strains. Conclusion:In 2024, Bordetella pertussis isolates in Liaocheng City exhibit distinct clonal epidemic characteristics, with the predominant antigenic genotype being ptxP3/ ptxA1/ ptxB1/ ptxC4/ ptxD1/ ptxE4/ fhaB1/ fim2-1/ fim3-1/ prn150. All isolates are resistant to macrolide antibiotics.

Objective:To evaluate the effect of arctigenin (ARG) on cognitive dysfunction induced by sevoflurane anesthesia in aged rats and the role of autophagy-mediated pyroptosis.Methods:Fifty SPF male Sprague-Dawley rats, aged 18-20 months, weighing 550-600 g, were divided into 5 groups ( n=10 each) using a random number table method: control group (C group), sevoflurane anesthesia group (Sev group), sevoflurane anesthesia+ ARG group (Sev+ ARG group), sevoflurane anesthesia+ autophagy inducer rapamycin group (Sev+ RAPA group), and sevoflurane anesthesia+ ARG+ autophagy inhibitor 3-methyladenine (3-MA) group (Sev+ ARG+ 3-MA group). Except for group C, the rats in the other groups inhaled 6% sevoflurane for 3 h to establish the cognitive impairment model. At 30 min before anesthesia, ARG 20 mg/kg was intraperitoneally injected in Sev+ ARG group, rapamycin 7.5 mg/kg was intraperitoneally injected in Sev+ RAPA group, and ARG 20 mg/kg (dissolved in dimethyl sulfoxide) was intraperitoneally injected, followed by immediate intraperitoneal injection of 3-MA 1.5 mg/kg in Sev+ ARG+ 3-MA group. The equal volume of dimethyl sulfoxide was intraperitoneally injected in C group and Sev group. The Morris water maze test was conducted to assess the cognitive function at 48 h after the end of administration. After completion of the Morris water maze test, the hippocampal tissue was taken under deep anesthesia for observation of the pathological changes (after HE staining) which were scored and for determination of neuronal pyroptosis (after propidium iodide staining) and expression of neuronal autophagy-related proteins (microtubule-associated protein 1 light chain 3 [LC3], Beclin-1, p62), pyroptosis-related proteins (NOD-like receptor protein 3 [NLRP3], apoptosis-associated speck-like protein containing a CARD [ASC], pro-cysteine aspartate-specific protease 1 [pro-caspase-1], cleaved-caspase-1, gasdermin D [GSDMD], and N-terminal fragment of gasdermin D [GSDMD-N], interleukin-1β [IL-1β] and IL-18). Results:Compared with C group, the escape latency was significantly prolonged, the time of staying at the original platform quadrant was shortened, the number of crossing the original platform was reduced, the hippocampal injury score and neuronal pyroptosis rate were increased, LC3Ⅱ/LC3Ⅰ ratio was decreased, the expression of Beclin-1 was down-regulated, the expression of p62, NLRP3, ASC, IL-1β and IL-18 was up-regulated, and the cleaved-caspase-1/pro-caspase-1 ratio and GSDMD-N/GSDMD ratio were increased in Sev group ( P<0.05). Compared with Sev group, the escape latency was significantly shortened, the time of staying at the original platform quadrant was prolonged, the number of crossing the original platform was increased, the hippocampal injury score and neuronal pyroptosis rate were decreased, LC3Ⅱ/LC3Ⅰ ratio was increased, the expression of Beclin-1 was up-regulated, the expression of p62, NLRP3, ASC, IL-1β and IL-18 was down-regulated, and the cleaved-caspase-1/pro-caspase-1 ratio and GSDMD-N/GSDMD ratio were decreased in Sev+ ARG group and Sev+ RAPA group ( P<0.05). Compared with Sev+ ARG group, the escape latency was significantly prolonged, the time of staying at the original platform quadrant was shortened, the number of crossing the original platform was reduced, the hippocampal injury score and neuronal pyroptosis rate were increased, LC3Ⅱ/LC3Ⅰ ratio was decreased, the expression of Beclin-1 was down-regulated, the expression of p62, NLRP3, ASC, IL-1β and IL-18 was up-regulated, and the cleaved-caspase-1/pro-caspase-1 ratio and GSDMD-N/GSDMD ratio were increased in Sev+ ARG+ 3-MA group ( P<0.05). Conclusions:AGR can alleviate sevoflurane anesthesia-induced cognitive dysfunction in aged rats, and the mechanism is related to reduction of autophagy-mediated cell pyroptosis.

Objective:To explore the molecular epidemiological characteristics of human metapneumovirus (HMPV) in children with acute respiratory infection (ARI) in Beijing from 2023 to 2024.Methods:In the longitudinal study, 9 834 children with ARI were enrolled from August 2023 to December 2024, including the influenza-like illness (ILI) group from emergency and outpatient department receiving influenza virus (Flu) and HMPV test and the ARI inpatient group for 13 common respiratory pathogen screening test including HMPV, Flu, respiratory syncytial virus, and so on. All respiratory samples positive with HMPV were genotyped by amplifying and sequencing of G gene and further phylogenetic analysis. The χ2 test and Wilcoxon rank-sum test were used to compare the positive rate and basic clinical data of the 2 groups. Results:Among 9 834 enrolled patient, there were 5 276 male and 4 558 female children, with age 5.4 (1.9, 8.2) years. In ILI group of 1 460 patients, there were 83 cases (5.7%) positive for HMPV, with the age 4.9 (3.6, 6.6) years and children under 6.0 years old 59 cases (71.1%). Among 8 374 ARI inpatients, there were 256 cases (3.1%) positive for HMPV, with age 3.5 (1.3, 6.4) years and children under 6.0 years old 188 cases (73.4%). The HMPV positive rate and the age of children positive for HMPV in ARI inpatient group were significantly lower than that in ILI group (both P<0.001). In December, 2024, the HMPV positive rates of ILI and ARI inpatient group (21.3% (17/80), 15.0% (47/314)) were significantly higher than the total positive rates of each group (both P<0.001). Among 279 subtyped specimens, there were 155 cases (55.6%) belonging to genotype A and 124 cases (44.4%) belonging to genotype B. Sub-lineage A2.2.2 containing 111nt-insertions was predominate one in 2023 with positive ratio 89.2% (91/102), and B2 was predominate in 2024 with positive ratio 64.4% (114/177). Conclusions:From 2023 to 2024, the positive rate of HMPV in the ILI group was higher than that in the ARI inpatient group, suggesting a common epidemic of HMPV infection. Children positive for HMPV in the ARI inpatient group were younger than that in the ILI group. A severe epidemic of HMPV was observed in the winter of 2024, which requires attention. Sub-lineage A2.2.2 with 111nt-duplicate insertions and B2 were the predominant epidemic strains in 2023 and 2024, respectively.