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To investigate the axial compression behavior of composite columns with high-strength concrete-filled steel tube flanges and honeycombed steel web (STHHC) under load during freeze–thaw cycles, 48 full-scale composite column specimens were designed with different parameters: the restraint effect coefficient (ξ), concrete strength (fcu), number of freeze–thaw cycles (nd), slenderness ratio (λ), space–height ratio (s/hw), and hole–height ratio (d/hw). The finite element models of STHHC composite columns were simulated using ABAQUS finite element software (Version: 2021). The modeling method's rationality was verified by comparing simulation results with experimental outcomes. Based on the finite element model, a parametric analysis of the composite columns under freeze–thaw cycles was conducted, analyzing their failure modes and load-bearing processes. The results indicate that the bearing capacity of the STHHC increased with increases in ξ and fcu, and decreased with a rise in λ. In contrast, the influence of s/hw and d/hw on the ultimate bearing capacity of the composite columns was relatively minor. An equation for calculating the axial bearing capacity of the STHHC composite columns under freeze–thaw cycles was derived using statistical regression methods and considering the impact of different parameters on the axial compressive performance of the composite columns, laying the foundation for the promotion and application of this type of composite column in practical engineering projects. [ABSTRACT FROM AUTHOR]

To study the eccentric compression mechanical properties of ECC and UHPC filled-in double steel tubular (EUFDST) composite columns, 35 full-scale EUCFDST composite column specimens were designed by ABAQUS software with the slenderness ratio (λ), UHPC cylinder compressive strength (fcu), inner and outer steel tubular strength (fy1, fy2), inner and outer steel tubular thickness (t1, t2), inner and outer steel tubular diameter ratio (Ω), eccentricity (e), and fiber content (γ) as the main parameters. By comparison with the simulation of the existing test, the correctness of the finite element modeling is verified. The parameter analysis of 35 full-scale EUFDST composite columns was carried out to obtain the eccentric load-mid-span deflection curve of the specimens. The failure mechanism, ductility coefficient, and stiffness degradation of the composite columns under different parameters were analyzed, and the section of the composite column was verified to satisfy the plane section assumption. The variation trend of maximum load-bearing capacity and the ductility of composite columns under different parameter conditions was obtained. By introducing the eccentricity correction coefficient and slenderness ratio correction coefficient, the calculation equation of the eccentric maximum load-bearing capacity of EUCFDST composite columns is statistically regressed, which provides a basis for the practical use of these columns. [ABSTRACT FROM AUTHOR]

Abnormal fetal growth increases risks of childhood health complications. Vitamin A supplementation (VAS) is highly accessible, but literature inconsistency regarding effects of maternal VAS on fetal and childhood growth outcomes exists, deterring pregnant women from VAS during pregnancy. This meta-analysis aimed to analyze effects of vitamin A only or vitamin A + co-intervention during pregnancy in healthy mothers (MH) or with complications (MC, night blindness and HIV positive) on perinatal growth outcomes, also assess VAS dose impacts. The Cochrane Library, PubMed, ScienceDirect, Scopus, Embase and Web of Science databases were searched from inception to July 15, 2021. We covered subgroup analyses, including VAS in MH or MC within randomized controlled trial (RCT) or observational studies (OS). Fifty-five studies were included in this meta-analysis (426,098 pregnancies). Vitamin A decreased risk of preterm birth by 9% in MH-RCT (P < 0.001), by 62% in MH-OS (P = 0.029), by 10% in MC-RCT (P = 0.089); decreased LBW by 24% in MC-RCT (P = 0.032); increased neonatal weight in MC-RCT (SMD 0.96; P = 0.051). Besides, vitamin A + co-intervention decreased risks of preterm by 18% in MH-OS (P = 0.021); LBW by 25% in MH-OS (P < 0.001); by 32% in MC-RCT (P = 0.006); decreased neonatal defects by 33% in MH-OS (P = 0.064); decreased anemia by 25% in MH-OS (P = 0.0003); increased neonatal weight in MH-OS (SMD 0.51; P = 0.014); and increased neonatal length in MH-OS (SMD 1.83; P = 0.013). Meta-regression of VAS dose with individual outcomes was not significant, and no side effects were observed for VAS doses up to 4000 mcg (RAE/d). Regardless of maternal health conditions, VAS during pregnancy can safely and effectively improve fetal development and neonatal health even in mothers without VAD. [ABSTRACT FROM AUTHOR]

Abstract Background Increasing evidences have suggested that autoantibodies against muscarinic-2 acetylcholine receptor (anti-M2-R) may play an important role in the development of atrial fibrillation (AF). Predictive value of pre-procedural anti-M2-R for the recurrence of AF after radiofrequency catheter ablation is still unclear. Methods Totally 76 AF patients with preserved left ventricular systolic function were prospectively enrolled and subjected to ablation after the detection of serum anti-M2-R by enzyme linked immunosorbent assay. These patients were given follow-up examination for one year after ablation. Risk estimation for the recurrence of AF was performed using the univariate and multivariate logistic regression. Results In AF group, serum anti-M2-R was significantly higher than that in the control group in terms of frequency (40.8% versus 11.7%; p < 0.001) and titer (1:116 versus 1:29; p < 0.001). Compared with paroxysmal AF patients, persistent AF patients had higher frequency (57.6% versus 27.9%; p = 0.009) and titer (1:132 versus 1:94; p = 0.012) for autoantibodies. During one-year follow-up examination after ablation, the recurrence of AF was observed in 25 (32.9%) patients. Multivariate analysis showed that pre-procedural serum anti-M2-R was an independent predictor for the recurrence of AF at the time point of 12 months after ablation (odds ratio: 4.701; 95% confidence interval: 1.590-13.894; p = 0.005). Conclusions In AF patients, the frequency and titer of serum anti-M2-R were significantly higher than those in the control group with sinus rhythm. Pre-procedural serum anti-M2-R was an independent predictor for the recurrence of AF one year after radiofrequency catheter ablation.

Background: Autoantibody against M2-muscarinic acetylcholine receptor (anti-M2AChR) has a biological effect similar to a vagus agonist. Digoxin has a function of vagus nervous system stimulation. We hypothesized that anti-M2AChR is highly correlated with digoxin in patients with chronic heart failure (CHF). Methods: Synthetic M2AChR peptides served as the target antigen in an ELISA were used to screen the sera of 80 CHF patients, who were separated into a negative (–) or positive (+) anti-M2AChR group according to their anti-M2AChR reactivity. Echocardiography and serum digoxin concentration (SDC) were performed at baseline and after 1 year of digoxin in combination with the standard treatment regime. The end-point events were compared over 1 year of follow-up. Results: Seventy-two CHF patients completed the final data analysis, including 32 (+)anti-M2AChR and 40 (–)anti-M2AChR patients. The resting heart rate of the positive group was higher than that of the negative group at baseline (p < 0.05; 89.0 ± 1.6 vs. 83.8 ± 1.1 bpm). Both groups showed improvement in the left ventricular end-diastolic and end-systolic dimensions and ejection fraction with digoxin in combination with the standard treatment regime for 1 year (all p < 0.01). However, the 32 patients with (–)anti-M2AChR had greater improvements than the 40 patients with (+)anti-M2AChR, and this was accompanied by a marked decrease of rehospitalization (all p < 0.01) but not of cardiovascular mortality after 1 year. The SDC of patients with (–)anti-M2AChR was significantly lower than that of patients with (+)anti-M2AChR (p< 0.05; 0.63 ± 0.05 vs.1.16 ± 0.06 ng/mL) and had a positive correlation with anti-M2AChR (r = 0.81, p < 0.001). Conclusion: These results suggested that anti-M2AChR could be a useful biomarker of vagus nerve overactivation and is associated with a poor response to digoxin treatment in CHF patients. [ABSTRACT FROM AUTHOR]

Introduction: The purpose of this study was to investigate the predictive factors of atrial fibrillation (AF) recurrence in patients after first-time radiofrequency catheter ablation (RFCA) and to develop a nomogram predictive model that can provide valuable information for determining the ablation strategy., Methods: In total, 500 patients who had received first-time RFCA for AF were retrospectively enrolled in the study. The patients were divided into a training cohort ( n  = 300) and a validation cohort ( n  = 200) randomly at a 6:4 ratio. Lasso and multivariate logistic regression analyses were used to screen the predictors for AF recurrence during a 2-year follow-up. The C-index and a calibration plot were used to detect the discriminative ability and calibration of the nomogram. The performance of the nomogram was assessed compared with the APPLE score, CAAP-AF score, and MB-LATER score using the receiver operating characteristic (ROC) curve, decision curve analysis (DCA), integrated discrimination index (IDI), and net reclassification index (NRI)., Results: A total of 78 patients experienced the recurrence of AF after first-time RFCA in the training cohort. The six strongest predictors for AF recurrence in the training cohort were persistent AF, duration of AF, left atrial diameter (LAD), estimated glomerular filtration rate (eGFR), N-terminal pro-brain natriuretic peptide (NT-proBNP), and autoantibody against M2-muscarinic receptor (anti-M2-R). Based on the above six variables, a nomogram prediction model was constructed with a C-index of 0.862 (95% CI, 0.815-0.909), while the C-index was 0.831 (95% CI, 0.771-0.890) in the validation cohort. DCA showed that this nomogram had greater net benefits compared with other models. Furthermore, the nomogram showed a noticeable improvement in predictive performance, sensitivity, and reclassification for AF recurrence compared with the APPLE score, CAAP-AF score, or MB-LATER score., Conclusion: We established a novel predictive tool for AF recurrence after the first-time RFCA during a 2-year follow-up period that could accurately predict individual AF recurrence., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The reviewer C-XJ declared a shared affiliation with the authors to the handling editor at the time of review., (© 2024 Ma, Zou, Zhang, Zhang and Zhang.)