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Whether the oilfield sewage index can reach the reinjection specification is a crucial issue that is urgently need to be solved in polymer flooding systems. Thus the coagulability and floc morphology development of dual coagulants was systematically studied in different pH oily wastewaters. Acidification improved the deprotonation ability of coagulant. Hydrophobic associative polyaluminum silicate-poly dimethyl diallyl ammonium chloride (PASSC-PD) resolved the problem of excessive acid addition. The dual coagulants prepared not only preserved the high charge density of polyaluminum silicate (PASS) itself but also made it have the hydrophobic association and strong bridging ability. Besides, PASSC-PD was compared with hydrophobic associative polyaluminum silicate (PASS-C), PASS, and poly dimethyl diallyl ammonium chloride (PDMDAAC) pertaining to the polymer flooding oily sewage of Daqing Oilfield. The coagulation result demonstrated that PASSC-PD exhibited more advantageous turbidity and oil removal efficiencies than PASS-C, PASS, and PDMDAAC. The floc morphology result showed that adding dual coagulant made the petal-like floc of oily sewage larger at the pH value of 6. Furthermore relevant results evidenced that the coagulant had more successful fruits of turbidity removal of 96.5% and oil removal of 96.3% under weak acid conditions. These can satisfy the reinjection condition of oily sewage. [ABSTRACT FROM AUTHOR]

Aims The aim of this study was to investigate the outcomes of catheter ablation (CA) in preventing arrhythmic events among patients with symptomatic Brugada syndrome (BrS) who declined implantable cardioverter defibrillator (ICD) implantation. Methods and results A total of 40 patients with symptomatic BrS were included in the study, of which 18 refused ICD implantation and underwent CA, while 22 patients received ICD implantation. The study employed substrate modification (including endocardial and epicardial approaches) and ventricular fibrillation (VF)-triggering pre-mature ventricular contraction (PVC) ablation strategies. The primary outcomes were a composite endpoint consisting of episodes of VF and sudden cardiac death during the follow-up period. The study population had a mean age of 43.8 ± 9.6 years, with 36 (90.0%) of them being male. All patients exhibited the typical Type 1 BrS electrocardiogram pattern, and 16 (40.0%) were carriers of an SCN5A mutation. The Shanghai risk scores were comparable between the CA and the ICD groups (7.05 ± 0.80 vs. 6.71 ± 0.86, P = 0.351). Ventricular fibrillation–triggering PVCs were ablated in 3 patients (16.7%), while VF substrates were ablated in 15 patients (83.3%). Epicardial ablation was performed in 12 patients (66.7%). During a median follow-up of 46.2 (17.5–73.7) months, the primary outcomes occurred more frequently in the ICD group than in the CA group (5.6 vs. 54.5%, Log-rank P = 0.012). Conclusion Catheter ablation is an effective alternative therapy for improving arrhythmic outcomes in patients with symptomatic BrS who decline ICD implantation. Our findings support the consideration of CA as an alternative treatment option in this population. [ABSTRACT FROM AUTHOR]

Background. Limited randomized controlled studies showed that thoracoscopic surgical left atrial ablation was not superior to catheter ablation (CA) in patients with persistent atrial fibrillation (PerAF). Right atrium might play an important role in triggering and maintaining atrial fibrillation (AF) in patients with PerAF. This study aimed to compare the efficacy of thoracoscopic surgical biatrial ablation versus CA in patients with PerAF. Methods. Patients with PerAF underwent thoracoscopic surgical biatrial ablation or CA were included in this study. Propensity score matching (1 : 2) was applied to select patients in CA group and surgical ablation (SA) group. The primary endpoint was to compare the probability of freedom from atrial tachyarrhythmias between SA and CA. Atrial tachyarrhythmia recurrence was defined as any atrial tachyarrhythmias longer than 30 s documented by 24-hour Holter monitoring after the 3-month blanking period. Results. After propensity score matching, 51 patients in surgical biatrial ablation group and 102 patients in CA group were enrolled (mean left atrial diameter: 45.8 mm). The probability of freedom from atrial tachyarrhythmias on antiarrhythmia drugs was 62.7%, 60.6%, and 60.6% in SA group and 42.0%, 39.6%, and 36.7% in CA group at 12, 24, and 36 months, respectively (p = 0.011), and off antiarrhythmia drugs were 56.9%, 52.5%, and 52.5% in SA group and 36.0%, 31.4%, and 27.5% in CA group at 12, 24, and 36 months, respectively (p = 0.007). After adjustment of age, sex, left atrial diameter, and AF duration history, multivariable Cox regression analysis suggested that SA procedure was an independent factor to reduce the risk of atrial tachyarrhythmia recurrence (HR: 0.589, 95% CI 0.370–0.937, p = 0.025). Conclusion. Compared with CA, thoracoscopic surgical biatrial ablation might achieve superior effectiveness for patients with PerAF. [ABSTRACT FROM AUTHOR]