Publications by authors named "Masaaki Kanahara"

Composite particles with varying morphologies composed of gold nanoparticles (Au NPs) and polymers were fabricated based on a combination of electrostatic interactions between the polymer particles and Au NPs and diffusion processes. The positively charged polymer particles were prepared from amino-terminated polystyrene (PS-NH2) and amino-terminated 1,2-polybutadiene (PB-NH2). Adsorption of citrate-stabilized Au NPs resulted in three different distribution states of Au NPs in the polymer particles, depending on the glass transition temperature (Tg) and molecular weight of the polymer.

View Article and Find Full Text PDF

Background: Measurement of flow-mediated dilation (FMD) is well known as a noninvasive method for an assessment of vascular endothelial function. However, the reproducibility is a major issue of FMD measurement. The purpose of this study is to examine the reproducibility of the new FMD measurement with medial epicondyle method.

View Article and Find Full Text PDF

In this report, we show a simple route to fabricate Janus particles having magnetic nanoparticles inside them, which can respond and rotate along to magnetic fields. By solvent evaporation from the tetrahydrofran solution of polymer stabilized γ-Fe2O3 nanoparticles, polystyrene (PS), and polyisoprene containing water, aqueous dispersion of Janus microparticles were successfully prepared, and the γ-Fe2O3 nanoparticles were selectively introduced into the PS phase. We demonstrate rotation and accumulation of Janus particles by using a neodymium magnet.

View Article and Find Full Text PDF

Introduction: Pseudoprolongation of activated partial thromboplastin time (APTT) is a serious problem in anticoagulation therapy for patients with high hematocrit, such as cyanotic congenital heart diseases. APTT pseudoprolongation occurs when APTT assay is performed using routinely used vacuum sampling tubes containing citrate. Because the plasma fraction is small in high-hematocrit blood, the prescribed volume of citrate would be excessive for APTT assay, resulting in prolongation of clotting or APTT pseudoprolongation.

View Article and Find Full Text PDF

Background: The characteristic features of QRST integral mapping in the Brugada-type resting ECG of patients at a high risk for life-threatening ventricular arrhythmias were examined.

Methods And Results: QRST integral mapping was performed in 11 Brugada-type ECG patients with histories of aborted sudden death, spontaneous ventricular tachycardia and fibrillation (VT/VF) or programmed electric stimulation-inducible VT/VF (high risk group); 13 Brugada-type ECG patients without a history of such events (low risk group); and 21 age-matched healthy controls. Individual QRST isointegral maps revealed the minimum integral in the mid-to-right upper chest in 100% and 85% of the control and low risk groups, respectively, whereas this integral was 64% in the upper right back of the high risk group (p<0.

View Article and Find Full Text PDF