Surfactant-mediated morphology evolution and self-assembly of cerium oxide nanocrystals for catalytic and supercapacitor applications.

Surfactant plays a remarkable role in determining the growth process (facet exposition) of colloidal nanocrystals (NCs) and the formation of self-assembled NC superstructures, the underlying mechanism of which, however, still requires elucidation. In this work, the mechanism of surfactant-mediated morphology evolution and self-assembly of CeO2 nanocrystals is elucidated by exploring the effect that surfactant modification has on the shape, size, exposed facets, and arrangement of the CeO2 NCs. It is directly proved that surfactant molecules determine the morphologies of the CeO2 NCs by preferentially bonding onto Ce-terminated {100} facets, changing from large truncated octahedra (mostly {111} and {100} exposed), to cubes (mostly {100} exposed) and small cuboctahedra (mostly {100} and {111} exposed) by increasing the amount of surfactant. The exposure degree of the {100} facets largely affects the concentration of Ce3+ in the CeO2 NCs, thus the cubic CeO2 NCs exhibit superior oxygen storage capacity and excellent supercapacitor performance due to a high fraction of exposed active {100} facets with great superstructure stability.

Long-term follow-up in patients with Brugada Syndrome in South China.

OBJECTIVE: To evaluate the presence of Brugada electrocardiogram (ECG) pattern, clinical characteristics, treatment, and long-term prognosis of Brugada syndrome in southern Chinese population. METHODS: This prospective study consisted of a consecutive series of patients with diagnostic coved type I Brugada ECG pattern at baseline between January 2007 and February 2020. Histories of symptoms including ventricular tachycardia (VT)/ventricular fibrillation (VF) episode, syncope, and family history of Brugada Syndrome (BrS) or unexplained sudden cardiac death were collected. Electrophysiological study and implantable cardioverter-defibrillator (ICD) were performed. All patients included in this study were followed up in the outpatient department every 6 months after baseline evaluation. Occurrences of syncope, VF, and sudden death were independently analyzed by two cardiologists. RESULTS: 45 (56.3%) patients were diagnosed with BrS. During a mean follow-up of 7.9 ± 3.6 years, six patients had experienced documented VF/sudden cardiac death (SCD) or recurrent syncope. Two patients experienced episodes of syncope more than once. Two patients experienced onset of electrical storm with a total of 11 episodes of VF. There were 50% of these events occurring in fever status. One of patient with BrS died of SCD. CONCLUSION: There was a very low prevalence of Brugada syndrome in southern Chinese population. The risk of arrhythmic events was low in asymptomatic patients. ICD was high effective in preventing SCD without adverse device outcome in long-term follow-up. Fever can lead to predispose to malignant arrhythmia, and aggressive treatment of febrile state in Brugada syndrome was recommended.

Tp-e and (Tp-e)/QT ratio as a non-invasive risk factors for malignant ventricular arrhythmia in patients with idiopathic ventricular premature complexes.

BACKGROUND: To evaluate the role of Tp-e and (Tp-e)/QT ratio in differentiating benign ventricular premature complex (VPC) and malignant polymorphic ventricular tachycardia (PVT). METHODS: From January 2017 to December 2017, patients with documented polymorphic ventricular tachycardia (PVT) or ventricular fibrillation (VF) were consecutive included and classified as PVT/VF group. Sixty age- and sex-matched healthy individuals were recruited as comparative control and subdivided into non-VPC and VPC group. Clinical characteristics and Tp-e and Tp-e/QT ratio between the three groups were compared. RESULTS: Tp-e and (Tp-e)/QT ratio were significantly higher in patients of PVT/VF group compared with the other two groups (P < .001). Episodes of syncope were more frequent in patients with PVT/VF (P < .05). The sensitivity and specificity of a Tp-e interval ≥86 ms for malignant arrhythmias triggered by VPCs were 88% and 66%, respectively, while the sensitivity and specificity of the Tp-e/QT ratio ≥0.24 were 82% and 70%, respectively. Five patients complained recurrence of syncope in the PVT/VF group and 1 patient died with mean follow-up of 18 months. CONCLUSION: Tp-e interval and the Tp-Te/QT ratio is significantly increased in patients with PVT/VF and may be used as a novel non-invasive marker of differentiating malignant and benign VPC.