Constraints on the cosmological parameters with three-parameter correlation of Gamma-ray bursts

As one of the most energetic and brightest events, gamma-ray bursts (GRBs) can be treated as a promising probe of the high-redshift universe. Similar to type Ia supernovae (SNe Ia), GRBs with same physical origin could be treated as standard candles. We select GRB samples with the same physical origin, which are divided into two groups. One group is consisted of 31 GRBs with a plateau phase feature of a constant luminosity followed by a decay index of about -2 in the X-ray afterglow light curves, and the other has 50 GRBs with a shallow decay phase in the optical light curves. For the selected GRB samples, we confirm that there is a tight correlation between the plateau luminosity $L_0$, the end time of plateau $t_b$ and the isotropic energy release $E_{\gamma,iso}$. We also find that the $L_0-t_b-E_{\gamma,iso}$ correlation is insensitive to the cosmological parameters and no valid limitations on the cosmological parameters can be obtained using this correlation. We explore a new three-parameter correlation $L_0$, $t_b$, and the spectral peak energy in the rest frame $E_{p,i}$ ($L_0-t_b-E_{p,i}$), and find that this correlation can be used as a standard candle to constrain the cosmological parameters. By employing the optical sample only, we find the constraints of $\Omega_m = 0.697_{-0.278}^{+0.402}(1\sigma)$ for a flat $\Lambda$CDM model. For the non-flat $\Lambda$CDM model, the best-fitting results are $\Omega_m = 0.713_{-0.278}^{+0.346}$, $\Omega_{\Lambda} = 0.981_{-0.580}^{+0.379}(1\sigma)$. For the combination of the X-ray and optical smaples, we find $\Omega_m = 0.313_{-0.125}^{+0.179}(1\sigma)$ for a flat $\Lambda$CDM model, and $\Omega_m = 0.344_{-0.112}^{+0.176}$, $\Omega_{\Lambda} = 0.770_{-0.416}^{+0.366}(1\sigma)$ for a non-flat $\Lambda$CDM model.Comment: Accepted for publication in The Astrophysical Journal, 13 pages, 9 figures and 2 table

A few recent developments in fluidized bed technology applications for fuel conversion

In recent years, the process concepts based on two-stage and dual bed have been widely adopted in developing fuel conversion technologies including pyrolysis, combustion, gasification and catalytic cracking. These provide indeed advantages of, for example, easy operation and control, poly-generation of products, and high efficiency in elimination of undesirable product or pollutants. The so-called micro fluidized bed analyzer (MFBRA) has been newly developed to measure reaction rates at arbitrary temperatures, giving a great support to fundamental research and technology developments for fuel conversion. This report intends to summarize the involved new concepts, major fundamental understandings, pilot test and/or industrial demonstrations of a few newly developed fuel conversion technologies. Concretely, it will report fluidized bed two-stage gasification (FBTSG), dual fluidized bed pyrolysis combustion (DBPC), fluidized bed cracking gasification (FBCG) and MFBRA. The FBTSG technology separates fuel pyrolysis in a FB pyrolyzer and char gasification in a transport bed gasifier. The latter enables high-temperature tar cracking under catalysis of char to enable remarkably low tar content in the produced gas [1]. For fuel with high contents of water and nitrogen, the DBPC technology first removes fuel water and most fuel volatile in a pyrolyzer. This, on the one hand, ensures stable combustion of the fuel, and on the other hand facilitates NOx reduction by char and pyrolysis gas [2]. The FBCG technology separates the catalytic cracking of heavy feedstock for liquid and the gasification of char, the cokes formed on the catalyst surface, to produce syngas and also to regenerate the catalyst. By using micro fluidized bed, the MFBRA is newly developed to enable the on-line pulse feeding and rapid heating of particle reactant. It effectively suppresses the interfacial diffusion limitation and minimizes the intra-particle diffusion [3]. Thus, MFBRA provides isothermal reaction analysis in comparison with that in TGA based on programmed heating. REFERENCES 1. X. Zeng, et al. Pilot verification of a low-tar two-stage coal gasification process with a FB pyrolyzer and fixed bed gasifier. Applied Energy, 115, 9–16, 2014. 2. P. Dagaut, et al. Experiments and kinetic modeling study of NO-reburning by gases from biomass pyrolysis in a JSR. Energy & Fuels, 17(3), 608-613, 2003. 3. J. Yu, et al. Kinetics and mechanism of solid reactions in a micro fluidized bed reactor. AIChE Journal, 56, 2905-2912, 2010

Radio Plateaus in Gamma-Ray Burst Afterglows and Their Application in Cosmology

The plateau phase in the radio afterglows has been observed in very few gamma-ray bursts (GRBs), and 27 radio light curves with plateau phase were acquired from the published literature in this article. We obtain the related parameters of the radio plateau, such as temporal indexes during the plateau phase ($\alpha_1$ and $\alpha_2$), break time (\Tbz) and the corresponding radio flux ($F_{\rm b}$). The two parameter Dainotti relation between the break time of the plateau and the corresponding break luminosity (\Lbz) in radio band is \Lbz \propto \Tbz^{-1.20\pm0.24}. Including the isotropic energy \Eiso and the peak energy \Epi, the three parameter correlations for the radio plateaus are written as \Lbz \propto \Tbz^{-1.01 \pm 0.24} \Eiso^{0.18 \pm 0.09} and \Lbz \propto \Tbz^{-1.18 \pm 0.27} \Epi^{0.05 \pm 0.28}, respectively. The correlations are less consistent with that of X-ray and optical plateaus, implying that radio plateaus may have a different physical mechanism. The typical frequencies crossing the observational band may be a reasonable hypothesis that causes the breaks of the radio afterglows. We calibrate GRBs empirical luminosity correlations as standard candle for constraining cosmological parameters, and find that our samples can constrain the flat $\Lambda$CDM model well, while are not sensitive to non-flat ${\Lambda}$CDM model. By combining GRBs with other probes, such as SN and CMB, the constraints on cosmological parameters are \om = 0.297\pm0.006 for the flat ${\Lambda}$CDM model and \om = 0.283\pm0.008, \oL = 0.711\pm0.006 for the non-flat ${\Lambda}$CDM model, respectively.Comment: 16 pages, 6 figures and 6 tables, accepted for publication in Ap

Percutaneous closure of a post-traumatic ventricular septal defect with a patent ductus arteriosus occluder

OBJECTIVE: Ventricular septal defects resulting from post-traumatic cardiac injury are very rare. Percutaneous closure has emerged as a method for treating this disorder. We wish to report our experience in three patients who underwent percutaneous closure of a post-traumatic ventricular septal defect with a patent ductus arteriosus occluder. METHODS: We treated three patients with post-traumatic ventricular septal defects caused by stab wounds with knives. After the heart wound was repaired, patient examinations revealed ventricular septal defects with pulmonary/systemic flow ratios (Qp/Qs) of over 1.7. The post-traumatic ventricular septal defects were closed percutaneously with a patent ductus arteriosus occluder (Lifetech Scientific (Shenzhen) Co., LTD, Guangdong, China) utilizing standard techniques. RESULTS: Post-operative transthoracic echocardiography revealed no residual left-to-right shunt and indicated normal ventricular function. In addition, 320-slice computerized tomography showed that the occluder was well placed and exhibited normal morphology. CONCLUSION: Our experiences indicate that closure of a post-traumatic ventricular septal defect using a patent ductus arteriosus occluder is feasible, safe, and effective

The role of EGFR mutation as a prognostic factor in survival after diagnosis of brain metastasis in non-small cell lung cancer: A systematic review and meta-analysis

Abstract Background The brain is a common site for metastasis in non-small-cell lung cancer (NSCLC). This study was designed to evaluate the relationship between the mutational of the epidermal growth factor receptor (EGFR) and overall survival (OS) in NSCLC patients with brain metastases. Methods Searches were performed in PubMed, EmBase, and the Cochrane Library to identify studies evaluating the association of EGFR mutation with OS in NSCLC patients through September 2017. Results 4373 NSCLC patients with brain metastases in 18 studies were involved. Mutated EGFR associated with significantly improved OS compared with wild type. Subgroup analyses suggested that this relationship persisted in studies conducted in Eastern, with retrospective design, with sample size ≥500, mean age of patients ≥65.0 years, percentage male < 50.0%, percentage of patients receiving tyrosine kinase inhibitor ≥30.0%. Finally, although significant publication bias was observed using the Egger test, the results were not changed after adjustment using the trim and fill method. Conclusions This meta-analysis suggests that EGFR mutation is an important predictive factor linked to improved OS for NSCLC patients with brain metastases. It can serve as a useful index in the prognostic assessment of NSCLC patients with brain metastases

Erratum to: Geometrical feature analysis and disaster assessment of the Xinmo landslide based on remote sensing data

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Survival after alcohol septal ablation versus conservative therapy in obstructive hypertrophic cardiomyopathy

Background: The impact of alcohol septal ablation (ASA) on the survival of patients with drug-refractory obstructive hypertrophic cardiomyopathy (HCM) remains unresolved. The aim of this study was to compare survival after ASA vs. conservative therapy. Methods: We studied a consecutive cohort of 274 patients with severe drug-refractory obstructive HCM, 229 in ASA group and 45 in conservative group. The primary endpoint was a composite of all-cause mortality and aborted cardiac arrest. Results: With a median follow-up of 4.3 years, primary endpoint occurred in 13 (5.7%) patients in the ASA group, and 8 (17.8%) patients in the conservative group. The 5- and 10-year survival free from primary endpoint of the ASA group (94.5% and 93.0%, respectively) was significantly better than that of the conservative group (78.3% and 72.2%, respectively, log-rank p = 0.009). Independent determinants of primary endpoint were ASA therapy (hazard ratio [HR] 0.22; 95% confidence interval [CI] 0.08–0.60; p = 0.003) and maximal septal thickness (HR 1.14; 95% CI 1.03–1.27; p = 0.011). Conclusions: In patients with severe drug-refractory obstructive HCM, survival after ASA is favorable and better than that of conservative therapy. ASA seems to improve survival