Anomalous oxidation of Fe-Si alloys under a low oxygen pressure at 800 °C

The authors acknowledge financial support by NSFC of China under the research projects (Nos. 50971129 and 51371183).Abstract The oxidation of three Fe-xSi alloys (x = 5, 9, 13 at.%) under 10−20 atm O2 at 800 °C formed in all cases SiO2 layers. For Fe-5Si this layer broke down and healed up periodically forming an anomalous internal oxidation zone with spherical and net-shaped SiO2 particles. The SiO2 layer formed on the other two alloys spalled off due to the growth and thermal stress accumulated. The critical silicon content needed for its external oxidation on Fe-Si alloys calculated according to an extension of Wagner's theory under the present experimental conditions is significantly smaller than the experimental results.PostprintPeer reviewe

Anomaly analysis of Hawking radiation from Kaluza-Klein black hole with squashed horizon

Considering gravitational and gauge anomalies at the horizon, a new method that to derive Hawking radiations from black holes has been developed by Wilczek et al. In this paper, we apply this method to non-rotating and rotating Kaluza-Klein black holes with squashed horizon, respectively. For the rotating case, we found that, after the dimensional reduction, an effective U(1) gauge field is generated by an angular isometry. The results show that the gauge current and energy-momentum tensor fluxes are exactly equivalent to Hawking radiation from the event horizon.Comment: 15 pages, no figures, the improved version, accepted by Eur. Phys. J.

Strategy and Long-term Outcomes of Endovascular Treatment for Budd–Chiari Syndrome Complicated by Inferior Vena Caval Thrombosis

ObjectivesThe aim of this study was to evaluate the strategy and long-term outcomes of endovascular treatment of Budd–Chiari syndrome (BCS) complicated by inferior vena cava (IVC) thrombosis.MethodsThe treatment strategy and outcomes of BCS complicated by IVC thrombosis were retrospectively evaluated in a single-center study. The treatment was aimed at the IVC thrombus, not hepatic vein occlusion. All 133 patients with BCS complicated by IVC thrombosis from February 2003 to March 2013 underwent endovascular treatment. For the fresh thrombus group (n = 75) recanalization was performed after transcatheter thrombolysis with urokinase. For the mixed thrombus group (n = 19) a small balloon pre-dilation of the IVC was performed first, followed by transcatheter thrombolysis using urokinase and a large balloon dilation of the IVC. For the old thrombus group (n = 39) a large balloon dilation or/and stent placement was performed directly. Pre- and post-treatment follow-ups were recorded.ResultsThe endovascular treatment was successful in 131 out of 133 patients (98.5%). Thirty seven patients had synchronous hepatic vein occlusion. The incidence of serious complications was 4.5% (6/133). Symptomatic pulmonary embolism occurred in three cases, cerebral hemorrhage in two, and cardiac tamponade in one. The cumulative 1-, 5-, and 10-year primary patency rate was 96.3%, 84.0%, and 64.6%, respectively. The cumulative 1-, 5-, and 10-year secondary patency rate was 99.0%, 96.1% and 91.3%, respectively. Segmental occlusion of the IVC and duration of anticoagulant therapy less than 6 months were independent risk factors for reocclusion.ConclusionsFor patients with BCS complicated by IVC thrombosis, an individualized treatment strategy based on the property of the thrombus can result in excellent long-term patency

Construction and functional analysis of nattokinase-producing cucumber obtained by the CRISPR-Cas9 system

Nattokinase (NK) is effective in the prevention and treatment of cardiovascular disease. Cucumber is rich in nutrients with low sugar content and is safe for consumption. The aim of this study was to construct a therapeutic cucumber that can express NK, which can prevent and alleviate cardiovascular diseases by consumption. Because the Bitter fruit ( Bt ) gene contributes to bitter taste but has no obvious effect on the growth and development of cucumber, so the NK-producing cucumber was constructed by replacing the Bt gene with NK by using CRISPR/Cas9. The pZHY988-Cas9-sgRNA and pX6-LHA-U6-NK-T-RHA vectors were constructed and transformed into Agrobacterium tumefaciens EHA105, which was transformed into cucumber by floral dip method. The crude extract of NK-producing cucumber had significant thrombolytic activity in vitro . In addition, treatment with the crude extract significantly delayed thrombus tail appearance, and the thrombin time of mice was much longer than that of normal mice. The degrees of coagulation and blood viscosity as well as hemorheological properties improved significantly after crude extract treatment. These findings show that NK-producing cucumber can effectively alleviate thrombosis and improve blood biochemical parameters, providing a new direction for diet therapy against cardiovascular diseases

Remarks on Hawking radiation as tunneling from the BTZ black holes

Hawking radiation viewed as a semiclassical tunneling process from the event horizon of the (2 + 1)-dimensional rotating BTZ black hole is carefully reexamined by taking into account not only the energy conservation but also the conservation of angular momentum when the effect of the emitted particle's self-gravitation is incorporated. In contrast to previous analysis of this issue in the literature, our result obtained here fits well to the Kraus-Parikh-Wilczek's universal conclusion without any modification to the Bekenstein-Hawking area-entropy formulae of the BTZ black hole.Comment: 12pages, no figure, use JHEP3.cls. Version better than published one in JHE

Multiple superconducting gap and anisotropic spin fluctuations in iron arsenides: Comparison with nickel analog

We present extensive 75As NMR and NQR data on the superconducting arsenides PrFeAs0.89F0.11 (Tc=45 K), LaFeAsO0.92F0.08 (Tc=27 K), LiFeAs (Tc = 17 K) and Ba0.72K0.28Fe2As2 (Tc = 31.5 K) single crystal, and compare with the nickel analog LaNiAsO0.9F0.1 (Tc=4.0 K) . In contrast to LaNiAsO0.9F0.1 where the superconducting gap is shown to be isotropic, the spin lattice relaxation rate 1/T1 in the Fe-arsenides decreases below Tc with no coherence peak and shows a step-wise variation at low temperatures. The Knight shift decreases below Tc and shows a step-wise T variation as well. These results indicate spinsinglet superconductivity with multiple gaps in the Fe-arsenides. The Fe antiferromagnetic spin fluctuations are anisotropic and weaker compared to underdoped copper-oxides or cobalt-oxide superconductors, while there is no significant electron correlations in LaNiAsO0.9F0.1. We will discuss the implications of these results and highlight the importance of the Fermi surface topology.Comment: 6 pages, 11 figure

The superconductivity at 18 K in LiFeAs system

A new iron arsenide superconducting system LiFeAs was found that crystallizes into a tetragonal structure with space group P4/nmm. The superconductivity with Tc up to 18 K was observed in the compounds. This simple 111 type layered iron arsenide superconductor can be viewed as an analogue of the infinite layer structure of copper oxides.Comment: 11 pages 3 Figure

High pressure synthesis of a new superconductor Sr2CuO2+xCl2-y induced by apical oxygen doping

Using the apical oxygen doping mechanism, i.e. a partial substitution of divalence O for the monovalence Cl, a p-type oxychloride cuprate superconductor, Sr2CuO2+xCl2-y, was synthesized at high pressure high temperature. The x-ray diffraction refinement suggests the superconductor crystallizes into a 0201 structure with space group I4/mmm and lattice parameters being a=3.92A, c=15.6 A. The magnetic susceptibility as well as resistance measurements indicated that the bulk superconductivity with transition temperature 30K was achieved in the sample.Comment: accepted by physica