Objective:To prepare and preliminarily identify the monoclonal antibodies(mAbs) specifically against 3D protein of Enterovirus 71(EV71),using bioinformatics to predict the epitopes of 3D,with HBc protein as a carrier.Methods: Artificial screening of 3D protein epitope sequences by bioinformatic method,inserted into the major immunodominant region(MIR) area of Hepatitis B virus core protein(HBc),to construct the recombinant protein.BALB/c mice were immunized with the recombinant virus like particles(VLPs),to prepare the mAbs against 3D protein of EV71.Affinity chromatography technology was used to purify the mAb.The indirect ELISA,ELISPOT,immunofluorescence and immunohistochemistry staining methods were used to identify the characteristic of the mAb.Results: We displayed 3D(aa34-43),3D(aa61-76) and 3D(aa151-164) epitopes by constructing fusion protein using HBc VLPs as a vector,after hybridization,one positive hybridoma cell line(3E1) was selected by ELISA.The isotype of 3E1 was IgG2a.The results of immunofluorescence and immunohistochemistry staining assay showed that the mAb 3E1 could specifically recognize EV71.Conclusion: The prepared mAb 3E1 can specifically recognizes the EV71,which laid the foundation for the detection of virus and further study on 3D protein,and verified the bioinformatics technology combined with HBc carrier displaying peptides could prepare mAb quickly and efficiently.

Objective:To investigate the impact of body mass index (BMI) on delayed extubation of patients with acute Stanford type A aortic dissection (ATAAD).Methods:A total of 400 ATAAD patients who were admitted to our hospital from October 2021 to October 2023 and underwent surgical treatment were selected as the research objects. According to BMI, they were divided into obese group (BMI≥28 kg/m 2, 119 cases) and non-obese group (BMI<28 kg/m 2, 281 cases). The differences of preoperative clinical characteristics, intraoperative and postoperative data between the two groups were compared. Starting from transferring to the ICU and ending with the first successful extubation, The risk factors of postoperative invasive mechanical ventilation time ≥ 48 h in ATAAD patients were analyzed, and the predictive efficacy of related factors for postoperative invasive mechanical ventilation time ≥ 48 h in ATAAD patients was evaluated. Results:Compared with the non-obese group, the proportion of hypertension, diabetes, admission heart rate, admission systolic blood pressure, admission diastolic blood pressure and preoperative white blood cell count in the obese group were significantly increased, and the differences were statistically significant ( P<0.05). The cardiopulmonary bypass time, aortic cross-clamp time, operation time, red blood cell transfusion volume, invasive mechanical ventilation time, secondary operation rate and total hospitalization cost in the obese group were significantly higher than those in the non-obese group, and the differences were statistically significant ( P<0.05). Univariate logistic regression analysis showed that BMI, cardiopulmonary bypass time, ascending aortic cross-clamp time, operation time, age, hypertension, and red blood cell transfusion were related factors for postoperative invasive mechanical ventilation time ≥48 h in ATAAD patients ( P<0.05). Logistic multivariate regression analysis showed that increased BMI ( OR=1.213, P<0.05) and increased age ( OR=1.020, P<0.05) were independent risk predictors of postoperative invasive mechanical ventilation time≥48 h in ATAAD patients. Receiver operating characteristic curve ( ROC) analysis showed that the area under the ROC curve ( AUC) of BMI for predicting the duration of postoperative invasive mechanical ventilation in ATAAD patients≥48 h was 0.682 ( P<0.05), and the best predictive cut-off value was 25.64 kg/m 2. Conclusion:BMI≥28kg/m 2 increases the difficulty of surgery and the duration of invasive mechanical ventilation in ATAAD patients. BMI has a high predictive value for the duration of invasive mechanical ventilation in ATAAD patients after surgery ≥48 h, and effective intervention measures can be formulated to improve the treatment effect of patients.