The Financial Risk Measurement EVaR Based on DTARCH Models.

The value at risk based on expectile (EVaR) is a very useful method to measure financial risk, especially in measuring extreme financial risk. The double-threshold autoregressive conditional heteroscedastic (DTARCH) model is a valuable tool in assessing the volatility of a financial asset's return. A significant characteristic of DTARCH models is that their conditional mean and conditional variance functions are both piecewise linear, involving double thresholds. This paper proposes the weighted composite expectile regression (WCER) estimation of the DTARCH model based on expectile regression theory. Therefore, we can use EVaR to predict extreme financial risk, especially when the conditional mean and the conditional variance of asset returns are nonlinear. Unlike the existing papers on DTARCH models, we do not assume that the threshold and delay parameters are known. Using simulation studies, it has been demonstrated that the proposed WCER estimation exhibits adequate and promising performance in finite samples. Finally, the proposed approach is used to analyze the daily Hang Seng Index (HSI) and the Standard & Poor's 500 Index (SPI).

Comparative effects of intensive ganglionated plexus ablation in treating paroxysmal atrial fibrillation and vasovagal syncope.

BACKGROUND: Ganglionated plexus (GP) ablation is used to treat atrial fibrillation (AF) and vasovagal syncope (VVS). However, the comparative effects of GP ablation in treating paroxysmal atrial fibrillation (PAF) and VVS have not been well studied. OBJECTIVE: The purpose of this study was to investigate the effects of intensive GP ablation on PAF and VVS. METHODS: PAF and VVS patients were enrolled in this study. Pulmonary vein isolation (PVI) was performed in the PAF group, and additional ablation was performed at GP sites. Anatomic ablation of left atrial GPs was performed in the VVS group. The primary endpoint was freedom from AF or other sustained atrial tachycardia and syncope recurrence. RESULTS: A total of 195 patients were enrolled: 146 patients with PAF, including eight patients with combined VVS (PAF group), and 49 patients with VVS (VVS group). Vasovagal response (VR) was achieved in 78 (53.4%) patients in the PAF group and 48 patients (98.0%) in the VVS group (P < .05). During the 17.8 ± 10.5 (range, 3-42) month follow-up, 126 (86.3%) patients were free of AF in the PAF group, and 45 (91.8%) patients in the VVS group had no syncope recurrence and significantly improved symptoms. CONCLUSIONS: Anatomically guided intensive GP ablation showed efficient clinical outcomes for both groups of patients. Compared with PAF patients, VVS patients had more VR during ablation in the left atrium. Furthermore, VR during ablation indicated a better prognosis in PAF patients.

Facile fabrication of Ce-decorated composition-tunable Ce@ZnCo2O4 core-shell microspheres for enhanced catalytic propane combustion.

The design of heterogeneous catalysts of high efficiency for complete oxidation of volatile organic compounds (VOCs) is a challenge. In the present study, propane is adopted as a VOC representative, and core-shell structured ZnCo2O4@CeO2 catalysts with Ce decoration were synthesized and tested for propane combustion. Through SEM, STEM, and EDX analyses, the structure of the ZnCo2O4@CeO2 catalysts was characterized. The results of activity evaluation demonstrate that the presence of Ce can significantly promote catalytic performance, and the most suitable Ce content has been verified. Furthermore, the optimized ZnCo2O4@CeO2 catalyst exhibits excellent thermal stability and strong resistance toward water. The superior catalytic performance over the optimized ZnCo2O4@CeO2 catalyst is attributed to the high concentration of surface lattice oxygen (O2-) and the presence of strong interactions between Ce and Co.

[Association of T393C single nucleotide polymorphism of GNAS1 gene with non-valvular atrial fibrillation].

OBJECTIVE: To analyze the association between T393C single nucleotide polymorphism (SNP) of GNAS1 gene and non-valvular atrial fibrillation (AF) in Chinese Han patients. METHODS: Ninety patients with non-valvular AF and 90 healthy subjects were examined for T393C SNP of GNAS1 gene using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The allele genotypes and the distribution of allele frequencies were analyzed and compared between the two groups. The relationship between allele frequency distribution characteristics and the heart rate variability (HRV) were also studied for analysis of the association between T393C SNP of GNAS1 gene and the autonomic nervous activation in non-valvular AF. RESULTS: The two groups showed a significant difference in the frequencies of genotypes of T393C SNP of GNAS1 gene and allele frequencies (P<0.01). CC genotype and T393C allele frequency were significantly increased in the case group. pNN50, LF, or LF/HF showed no significant difference between different genotypes (P<0.05). CONCLUTIONS: The T393C SNP of GNAS1 gene is closely associated with non-valvular AF in Chinese Han patients.

[Early repolarization syndrome and recurrent syncope in two Chinese pedigrees].

OBJECTIVE: to investigate the clinical characteristics in two families with early repolarization syndrome (ERS) and recurrent syncope. METHOD: all family members including the probands were screened with routine clinical examination, electrocardiography, echocardiography, Holter recording, chest x-ray, head-up tilt test and blood biochemistry. RESULTS: there was no clinical evidence of organic heart disease in all members from the two families. Proband 1 showed recurrent syncope, ERS and repeated torsade de pointes ventricular tachycardia and ventricular fibrillation were documented with resting ECG. ERS was detected in one brother, one nephew and one son from him and all were free of cardiac events including syncope, cardiac arrest and sudden cardiac death. Proband 2 showed recurrent syncope, ERS and ST segment arched upward elevation in V(1)-V(3) were documented by ECG. His father suffered sudden cardiac death at the age of 65 and asymptomatic ERS was detected in one of his nephew. CONCLUSIONS: ERS is not always linked with benign clinical course and can sometimes lead to repeated syncope, torsade de pointes ventricular tachycardia and ventricular fibrillation. Pedigree research is of importance for ERS.

[Association of ATP-binding cassette transporter A1 R219K polymorphism with atrial fibrillation].

OBJECTIVE: To investigate the association of ATP binding cassette transporter A1 (ABCA1) gene R219K polymorphisms with atrial fibrillation (AF) in Chinese population. METHODS: A total of 250 patients with AF and 250 control subjects were selected. Polymerase chain reaction-restricted fragments length polymorphism (PCR-RFLP) was used to determine the ABCA1 genotype, and the serum concentration of C-reactive protein (CRP) and high-density lipoprotein cholesterol (HDL-C) were measured in all the subjects. RESULTS: The frequency of the RR , RK , KK , allele R , allele K genotype of ABCA1 in AF group and control group was 42.0%, 42.8%, 15.2%, 34.0%, 43.2% and 22.8%, 63.4%, 36.6%, 55.6%, 44.4%, respectively. The frequency of the KK genotype was significantly higher in the control group than in the case group (P=0.03), and the frequency of the allele K genotype was significantly different between the two groups (P=0.012). The serum CRP concentrations was significantly higher in AF group than in the control group (P=0.004), but serum HDL-C level showed no difference between the two groups. The serum CRP concentrations were significantly higher in patients with RR genotype than in those with KK genotype (P=0.013), and patients with RR genotype had significantly lower HDL-C level than those with RK and KK genotypes (P=0.009 and 0.027, respectively). CONCLUSION: Patients with AF have elevated serum CRP level in comparison with healthy individuals, and the K allele of R219K polymorphism is an independent protective factor against AF.