Thermally Controlled Construction of Fe-N Active Sites on the Edge of a Graphene Nanoribbon for an Electrocatalytic Oxygen Reduction Reaction.

Pyrolytically prepared iron and nitrogen codoped carbon (Fe/N/C) catalysts are promising nonprecious metal electrocatalysts for the oxygen reduction reaction (ORR) in fuel cell applications. Fabrication of the Fe/N/C catalysts with Fe-N active sites having precise structures is now required. We developed a strategy for thermally controlled construction of the Fe-N structure in Fe/N/C catalysts by applying a bottom-up synthetic methodology based on a N-doped graphene nanoribbon (N-GNR).

Bimetallic M/N/C catalysts prepared from π-expanded metal salen precursors toward an efficient oxygen reduction reaction.

Nonprecious metal electrocatalysts are being explored as alternatives to platinum-group metal electrocatalysts for the oxygen reduction reaction (ORR) which is required for cathode materials in fuel cells. Herein, we describe a new method for preparing bimetallic nitrogen-containing carbon catalysts with high ORR activity using π-expanded M(salen) precursors. The M/N/C and bimetallic FeM/N/C ORR catalysts were obtained by pyrolysis of a mixture of a carbon support (Vulcan XC-72R) and the metal complex as a precursor.

The Impact of the Polymer Chain Length on the Catalytic Activity of Poly(N-vinyl-2-pyrrolidone)-supported Gold Nanoclusters.

Poly(N-vinyl-2-pyrrolidone) (PVP) of varying molecular weight (M  = 40-360 kDa) were employed to stabilize gold nanoclusters of varying size. The resulting Au:PVP clusters were subsequently used as catalysts for a kinetic study on the sized-dependent aerobic oxidation of 1-indanol, which was monitored by time-resolved in situ infrared spectroscopy. The obtained results suggest that the catalytic behaviour is intimately correlated to the size of the clusters, which in turn depends on the molecular weight of the PVPs.

Immunoglobulin binding (B1) domain mediated antibody conjugation to quantum dots for in vitro and in vivo molecular imaging.

A facile method for the preparation of antibody-quantum dot (QD) conjugates using the immunoglobulin binding (B1) domain of protein G is presented. The utility of antibody-QD conjugates using the B1 domain is demonstrated for fluorescence imaging of breast tumor cells in vitro and in vivo.

Decreased Defibrillation Threshold and Minimized Myocardial Damage With Left Axilla Implantable Cardioverter Defibrillator Implantation.

Background: To reduce myocardial damage caused by implantable cardioverter defibrillator (ICD) shock, the left axilla was studied as an alternative pulse generator implantation site, and compared with the traditional implantation site, the left anterior chest.

Methods and results: Computer simulation was used to study the defibrillation conduction pattern and estimate the simulated defibrillation threshold (DFT) and myocardial damage when pulse generators were placed in the left axilla and left anterior chest, respectively; pulse generators were also newly implanted in the left axilla (n=30) and anterior chest (n=40) to compare the corresponding DFT. On simulation, when ICD generators were implanted in the left axilla, compared with the left anterior chest, the whole heart may be defibrillated with a lower defibrillation energy (left axilla 6.

Efficacy and Myocardial Injury With Subcutaneous Implantable Cardioverter Defibrillators - Computer Simulation of Defibrillation Shock Conduction.

Background: Subcutaneous implantable cardiac defibrillator (S-ICD) systems have a lower invasiveness than traditional ICD systems, and expand the indications of ICD implantations. The S-ICD standard defibrillation shock output energy, however, is approximately 4 times that of the traditional ICD system. This raises concern about the efficacy of the defibrillation and myocardial injury.

Evaluation of defibrillation safety and shock reduction in implantable cardioverter-defibrillator patients with increased time to detection: A randomized SANKS study.

Background: The need for ways to minimize the number of implantable cardioverter-defibrillator (ICD) shocks is increasing owing to the risk of its adverse effects on life expectancy. Studies have shown that a longer detection time for ventricular tachyarrhythmia reduces the safety of therapies, in terms of syncope and mortality, but not substantially in terms of the success rate. We aimed to evaluate the effects of increased number of intervals to detect (NID) VF on the safety of ICD shock therapy and on the reduction of inappropriate shocks.

Simple observation of biofilm by scanning electron microscopy using ionic liquids.

Scanning electron microscopy (SEM) has been successfully used to image biofilms because of its high resolution and magnification. However, conventional SEM requires dehydration and metal coating of biological samples before observation, and because biofilms consist mainly of water, sample dehydration may influence the biofilm structure. When coated with an ionic liquid, which is a kind of salt that exists in the liquid state at room temperature, biological samples for SEM observation do not require dehydration or metal coating because ionic liquids do not evaporate under vacuum conditions and are electrically conductive.

Recombinant protein (EGFP-Protein G)-coated PbS quantum dots for in vitro and in vivo dual fluorescence (visible and second-NIR) imaging of breast tumors.

We report a one-step synthetic strategy for the preparation of recombinant protein (EGFP-Protein G)-coated PbS quantum dots for dual (visible and second-NIR) fluorescence imaging of breast tumors at the cellular and whole-body level.

Left axillary pacemaker generator implantation with a direct puncture of the left axillary vein.

Background: Pacemaker generators are routinely implanted in the anterior chest. However, where to place the generator may need to be considered from the mental, functional, and cosmetic standpoints.

Methods: In this study, we performed the left axillary pacemaker generator implantation with a direct puncture of the left axillary vein in 40 consecutive patients, and evaluated the late safety and efficacy of this implantation.

Ratiometric MRI sensors based on core-shell nanoparticles for quantitative pH imaging.

Ratiometric MRI sensors consist of paramagnetic cores and pH-sensitive polymer shells. The core-shell nanostructure enables the coexistence of two incompatible NMR relaxation properties in one particle. The sensors show pH sensitivity in transverse relaxivity (r2 ), but not in longitudinal relaxivity (r1 ).

Aqueous synthesis of glutathione-coated PbS quantum dots with tunable emission for non-invasive fluorescence imaging in the second near-infrared biological window (1000-1400 nm).

Glutathione-coated PbS quantum dots with tunable emission were synthesized in the aqueous phase and used for non-invasive tissue imaging in the second near-infrared biological window.

Lorentzian-like image blur of gold nanoparticles on thick amorphous silicon films in ultra-high-voltage transmission electron microscopy.

We quantitatively analyzed the contrast degradation and blur of 20-nm gold nanoparticles adsorbed on the top of amorphous silicon films of thicknesses of 0.54, 1.09, 1.

Structural modifications of dentinal microcracks with human aging.

Several studies have reported the mechanism of crack propagation with aging. Although structural modifications of dentinal microcracks with aging have been evaluated by observing the cracked surface using scanning electron microscope (SEM), very few attempts have been made at sectional observation of the microcracks inside dentine using transmission electron microscopy (TEM). The objectives of this study were to: (1) examine the process of dentinal microcrack formation using TEM and (2) to morphologically evaluate the relation between dentinal microcrack propagation and human aging.

Cost effectiveness of radiofrequency catheter ablation vs. medical treatment for atrial fibrillation in Japan. -Cost performance for atrial fibrillation-.

Background: Radiofrequency catheter ablation (RF) has recently become widely available for the treatment of atrial fibrillation (AF) and has broadened treatment options while confusing the selection of medication therapy or RF.

Methods And Results: Two drugs for the maintenance of sinus rhythm (Ry) and 2 drugs for control of the pulse rate (Ra) were selected and the costs of medication therapy were calculated. RF procedures were grouped into 2 groups each for persistent or paroxysmal AF (RF) and for chronic AF (RFChr), according to the cost of the devices used.

Catalytic activity and regeneration property of a Pd nanoparticle encapsulated in a hollow porous carbon sphere for aerobic alcohol oxidation.

A core-shell composite consisting of a palladium (Pd) nanoparticle and a hollow carbon shell (Pd@hmC) was employed as a catalyst for aerobic oxidation of various alcohols. The core-shell structure was synthesized by consecutive coatings of Pd nanoparticles with siliceous and carbon layers followed by removal of the intermediate siliceous layer. Structural characterizations using TEM and N(2) adsorption-desorption measurements revealed that Pd@hmC thus-obtained was composed of a Pd nanoparticle core of 3-6 nm in diameter and a hollow carbon shell with well-developed mesopore (ca.

Magnetic Cu-Ni (core-shell) nanoparticles in a one-pot reaction under microwave irradiation.

We successfully prepared face-centered cubic (fcc) Cu-Ni (core-shell) nanoparticles by intramolecular reduction of formate complexes of Cu(2+) and Ni(2+) with long-chain amine ligands in a one-pot reaction within an extremely short time realized only under microwave irradiation. Observation by an HAADF-STEM technique showed that the nanostructure in one particle consisted of a Ni-rich shell and a Cu-rich core. Cu(4)Ni(6) nanoparticles with an average size of 11.

Gender differences in patients referred for atrial fibrillation management to a tertiary center.

Background: Atrial fibrillation (AF) ablation is less frequently performed in women than in men. Although the prevalence of AF is slightly higher in men, this does not fully account for the lower number of AF ablations performed in women. This study sought to examine the effect of gender on referral for AF and subsequent AF management.

Behavior of fluorescent molecules bound to the interior of silica nanocapsules in various solvents.

Porous silica nanocapsules with 20% 3-aminopropyltrimethoxysilane (APS)-bound 6-carboxy-fluorescein (APS-fluorescein) and 80% APS molecules adsorbed on the surface of a 50-nm-diameter Au core were prepared by a modified core-shell method. Silica mesoporous nanocapsules were obtained after the Au cores were dissolved in sodium cyanide. The size of the pores in the silica shells corresponded to the area of the fluorescein (approximately 1.

High sintering resistance of platinum nanoparticles embedded in a microporous hollow carbon shell fabricated through a photocatalytic reaction.

Platinum (Pt) nanoparticles encapsulated in microporous carbon with a hollow structure (nPt@hC) were fabricated on the basis of a titanium(IV) oxide (TiO2) photocatalytic reaction. From the tomogram of a sample studied by using a transmission electron microscope (TEM), the Pt nanoparticles were found to be embedded in the carbon shell and were physically separated from each other by the carbon matrix. Owing to this unique structure, the Pt particles showed high resistance to sintering when subjected to thermal treatment at temperatures up to 800 degrees C.

Atrial fibrillation following device closure of patent foramen ovale.

Objectives: Recurrent embolic events after device closure of patent foramen ovale (PFO) have been related to incomplete closure. Another cause could be atrial fibrillation (AF). The aim of this study was to determine the incidence of AF in stroke patients after PFO closure.

His-Purkinje system re-entry in patients with clustering ventricular tachycardia episodes.

Aims: Multiple arrhythmia re-inductions were recently shown in His-Purkinje system (HPS) ventricular tachycardia (VT). We hypothesized that HPS VT was a frequent mechanism of repetitive or incessant VT and assessed diagnostic criteria to select patients likely to have HPS VT.

Methods And Results: Consecutive patients with clustering VT episodes (>3 sustained monomorphic VT within 2 weeks) were included in the analysis.

Wide QRS-complex tachycardia with variable VA-conduction: what is the mechanism?

We describe the case of a 16-year-old woman with a surgically corrected tetralogy of Fallot presenting with recurrent wide-QRS-complex tachycardia. The tachycardia could be induced and terminated with ventricular stimulation only. QRS morphology during sinus rhythm and tachycardia was identical and variable VA-conduction was observed.