As MRI contrast agents, more hydrophobic molecules reportedly accumulate in the liver and thus are potentially useful as liver MRI contrast agents. In this study, a generation-4 polypropylenimine diaminobutane dendrimer (DAB-Am64), which is expected to be more hydrophobic than the generation-4 polyamidoamine dendrimer (PAMAM-G4D), was used to synthesize a conjugate with 2-(p-isothiocyanatobenzyl)-6-methyl-diethylenetriaminepentaacetic acid (1B4M) [DAB-Am64-(1B4M-Gd) 64 ] for complexing Gd(III) ions. This DAB conjugate quickly accumulated in the liver and its characteristics were studied and compared with those of a PAMAM conjugate [PAMAM-G4D-(1B4M-Gd) 64 ], which is known to be a useful vascular MRI contrast agent, in regard to its availability as a liver MRI contrast agent. DAB-Am64-(1B4M-Gd) 64 accumulated significantly more in the liver and less in blood than PAMAM-G4D-(1B4M-Gd) 64 (P < 0.001). Contrast-enhanced MRI with DAB-Am64-(1B4M-Gd) 64 was able to homogeneously enhance liver parenchyma and visualize both portal and hepatic veins of 0.5 mm diameter in mice. In conclusion, DAB-Am64-(1B4M-Gd) 64

We studied a high-temperature superconducting synchronous motor assembled with melt-textured Gd-Ba-Cu-O bulk field magnets. The motor is an axial gap-type, brushless synchronous motor with eight rotating bulk field magnet poles. Liquid nitrogen is circulated to cool down the rotor components. Pulsed field magnetization was performed to excite the bulk field magnets by using a pair of the vortex-type armature copper windings under the zero-field cooling. The trapped peak field density on the surface of the bulk was varied from 0.5 T to 0.8 T. The trapped peak magnetic field 0.5 T on the surface of the bulk magnets provided the motor performance of 3.1 kW with 720 rpm. The field density distribution on the pole bulk magnet surface is anisotropic and different from the ideal conical shape. The optimized pulsed current waveform applied to the armature and the employing of a composite of bulk crystal magnets leading to a spatially homogeneous flux trapping are promising methods for reinforcement of the field flux from the rotor and the motor torque.Index Terms-High-temperature super-conducting motor, hightemperature superconductors, melt-processed bulk superconductors, melt-textured Gd123.

No abstract

No abstract

No abstract