Palladium nanoparticles loaded on nitrogen and boron dual-doped single-wall carbon nanohorns with high electrocatalytic activity in the oxygen reduction reaction

Palladium nanoparticles with a diameter of 2–4 nm supported on nitrogen and boron dual-doped single-wall carbon nanohorns (Pd-NBCNHs) are synthesized via a one-step method and their electrocatalytic activities are investigated for the oxygen reduction reaction (ORR) in alkaline media. The electrochemical results demonstrate that the oxygen reduction peak potential of Pd-NBCNHs is similar to that of commercial 20% Pt–C. Furthermore, Pd-NBCNHs show a more positive half-wave potential than 20% Pt–C and display better long-term stability and resistance to methanol than 20% Pt–C, which is attributed to the synergetic effect of the Pd nanoparticles and NBCNHs. As NBCNHs have abundant pyrrolic nitrogen, charged sites and defective structures, they not only act as a carrier, but also provide the active sites for oxygen adsorption during the oxygen reduction reaction process. The outstanding electrochemical performance makes Pd-NBCNHs promising to be applied in fuel cells.

Palladium nanoparticles with a diameter of 2–4 nm loaded on nitrogen and boron dual-doped single-wall carbon nanohorns (Pd-NBCNHs) are prepared via one-step method and their electrocatalytic activities are studied for the oxygen reduction reaction.     

Responses of the electron transfer capacity of soil humic substances to agricultural land-use types

Humic substances (HS) are redox-active organic compounds that constitute a major fraction of natural organic matter in soils. The electron transfer capacity (ETC) of soil HS is mainly dependent on the type and abundance of redox-active functional groups in their structure. It is unclear whether or not agricultural land-use types can affect the ETC of HS in soils. In the present study, we evaluate the responses of ETCs of soil humic acids (HA) and fulvic acids (FA) to different agricultural land-use types. Our results show that both HA and FA of paddy soil showed the highest ETCs, followed by tomato soil, celery cabbage soil, grapevine soil, and myrica rubra soil, respectively. Agricultural land-use types could affect the transformation and decomposition of HS in soils, and thus further change the intrinsic chemical structures associated with ETC. Consequently, the ETC of soil HS exerts a significant difference among different agricultural land-use types. The results of this study could give insight into the roles of HS redox properties on the transport, fate, and redox conversion of organic and inorganic pollutants in different agricultural soils.

Agricultural land-use types could affect the transformation and decomposition of HS in soils, and thus further change the intrinsic chemical structures associated with ETC.     

Long-term safety and effectiveness of paroxysmal atrial fibrillation ablation using a porous tip contact force-sensing catheter from the SMART SF trial

Journal of Interventional Cardiac Electrophysiology - The prospective, multicenter SMART SF trial demonstrated the acute safety and effectiveness of the 56-hole porous tip irrigated contact force...     

Interface Strength,Damage and Fracture between Ceramic Films and Metallic Substrates

Interface strength, damage and fracture properties between ceramic films and metallic substrates affect the service reliability of related parts. The films’ thickness, grain size and residual stress affect the interface properties and fracture behavior, thus related studies attract great attention. In this paper, the interface damage evolution and fracture behavior between ceramic films and metallic substrates were simulated by developing a three dimensional finite element model of alumina films on Ni substrates with cohesive elements in the interfaces. The interface fracture energy as a key parameter in the simulation was firstly determined based on its thermodynamic definition. The simulation results show the Mises stress distribution and damage evolution of the film/substrate structures during uniaxial tensile loading. Specially, when grain size of the films is in nanoscale, the interface strength increases obviously, agreeing with the previous experimental results. The effects of residual stress on interface properties was further simulated. The interface strength was found to decrease with increasing radial residual force and the axial residual pressure increases the interface strength. When the thickness of the films increases, the interface strength keeps a constant but the speed of interface damage becomes faster, that is, the thicker films show catastrophic fracture. The underlying mechanism of damage speed was analyzed. Understanding these size effects and the effects of residual stress is helpful to guide the design of related parts.     

Stereotactic body radiation therapy for refractory ventricular tachycardia secondary to cardiac lipoma: A case report

We present the case of a 29‐year‐old man who developed ventricular tachycardia (VT) secondary to a cardiac lipoma located adjacent to the interventricular groove, which could not be fully resected. Antiarrhythmic drugs and endocardial and epicardial ablation failed to prevent VT recurrence. Finally, noninvasive stereotactic body radiation therapy (SBRT) targeting the lipoma was performed, with a total dose of 24 Gy delivered in three fractions. The number of VT episodes was reduced from 189/24 h before SBRT to 0 after the procedure. At 4‐month follow‐up, there were no signs of therapy‐related complications. Our experience suggests that SBRT could emerge as a viable treatment option for patients with cardiac tumors who develop refractory ventricular arrhythmias.     

Successful Treatment of Idiopathic Hypereosinophilic Syndrome with Imatinib Mesylate: A Case Report

Patients with idiopathic hypereosinophilic syndrome (HES) show persistent hypereosinophilia of unknown etiology that is associated with end-organ damage. Different treatments, including the use of corticosteroids and cytotoxics, have been investigated for HES with modest success. We describe a patient with HES who had significant end-organ damage from hypereosinophilia and remained refractory to conventional therapy. Therapy with imatinib mesylate, a selective tyrosine kinase inhibitor that is highly effective in treating patients with BCR-ABL-positive chronic myeloid leukemia, was tried with the patient. The result was impressive, with hematologic remission achieved after 12 days of administration. Our finding concurs with recent reports that imatinib mesylate may be a promising agent in the treatment of some cases of HES.