Novel ferromagnetic materials of SmCo5 nanoparticles in single-nanometer size: chemical syntheses and characterizations.

We first succeeded in preparing ferromagnetic materials of SmCo(5) nanoparticles in sizes of single nanometers by a chemical route using a polyol process. In order to produce ferromagnetic SmCo(5) nanoparticles with a CaCu(5)-type structure, the chemical preparation was conducted under a molar ratio of 1:1.3 of Sm:Co as compositions of metallic precursors when tetraethylene glycol (TEG), and oleic acid and oleylamine were used as a reductant and protectant, respectively. However, XRD profiles of the products showed the presence of oxides and other by-products besides the CaCu(5)-type structured nanoparticles. The best metallic precursors and protective reagent to prevent oxidization under reaction were SmCl(3) and Co(acac)(3), and 1-adamantanecarboxylic acid (ACA) and poly(N-vinyl-2-pyrrolidone) (PVP), respectively when TEG was used as the reducing reagent. We found that oxides and other by-products were not detected and pure SmCo(5) nanoparticles with the CaCu(5)-type structure were prepared under the chemical condition. The SmCo(5) nanoparticles coated by ACA and PVP were 6.2 nm in diameter and showed a coercivity of 1500 Oe at 300 K.

Resolution of pulmonary arteriovenous fistula by redirection of hepatic venous blood.

We report an 8-year-old girl whose unilateral pulmonary arteriovenous fistula (PAVF) disappeared after we redirected hepatic venous blood to the affected lung. This case provides strong evidence that formation of a PAVF depends only on the presence or absence of hepatic venous blood in the pulmonary circulation.

Direct synthesis and characterizations of fct-structured FePt nanoparticles using poly(N-vinyl-2-pyrrolidone) as a protecting agent.

FePt alloy in a bulk state is well known as a magnetic material. FePt nanoparticles, which are protected by poly(N-vinyl-2-pyrrolidone) (PVP) and have a face-centered tetragonal (fct) structure at a size of a few nanometers in diameter, have been directly synthesized by a polyol process in high-boiling point tetraethylene glycol used as a reducing reagent for the reduction of Fe(III) acetylacetonate and Pt(II) acetylacetonate. Their magnetic properties (coercivity and saturation magnetization) were dependent on the size and made progress as their diameters increased. The size in diameter was easily controlled by altering the content of PVP, the time for refluxing, and reaction temperature. FePt nanoparticles showed diameter-dependent coercivities at room temperature and they abruptly increased at over 4 nm in diameter. Ferromagnetic FePt nanoparticles with an fct structure were also synthesized at relatively low reaction temperature without refluxing. Likewise, as-synthesized FePt nanoparticles prepared by refluxing at 251 degrees C for 3 h displayed the fct structure and clearly indicated the ferromagnetism at room temperature. Reaction kinetics such as long refluxing time and slow temperature elevation rate were found to be important key factors to synthesize the ferromagnetic FePt nanoparticles although the reaction temperature was very critical as well.

Living-related lobar transplantation and simultaneous atrial septal defect closure in a young patient with irreversible pulmonary hypertension: a case report.

A 6-year-old boy was diagnosed as having atrial septal defect with oversystemic pulmonary hypertension, and gradually developed hypoxia and heart failure. At the age of 11, living-related bilateral lobar lung transplantation from his parents was indicated, because of his critical condition. The estimated forced vital capacity calculated by the donors' lower lobes was 104% of his age. The operation was carried out with simultaneous closure of the atrial septal defect under full cardiopulmonary bypass. The postoperative course was complicated with pulmonary edema and phrenic nerve palsy, which were eventually resolved. Six months after surgery he was free from heart failure and rehabilitating at home without oxygen. The final diagnosis was primary pulmonary hypertension with atrial septal defect. Living-related bilateral lobar lung transplantation with simultaneous intracardiac repair may be an optional strategy for children with Eisenmenger syndrome or primary pulmonary hypertension with intracardiac defect when cadaveric transplantation is not possible.