Washout of 10C and 11C implanted by radioactive beams in brain and thigh muscle of rabbits was studied. The biological washout effect in a living body is important in the range verification system or three-dimensional volume imaging in heavy ion therapy. Positron emitter beams were implanted in the rabbit and the annihilation gamma-rays were measured by an in situ positron camera which consisted of a pair of scintillation cameras set on either side of the target. The ROI (region of interest) was set as a two-dimensional position distribution and the time-activity curve of the ROI was measured. Experiments were done under two conditions: live and dead. By comparing the two sets of measurement data, it was deduced that there are at least three components in the washout process. Time-activity curves of both brain and thigh muscle were clearly explained by the three-component model analysis. The three components ratios (and washout half-lives) were 35% (2.0 s), 30% (140 s) and 35% (10 191 s) for brain and 30% (10 s), 19% (195 s) and 52% (3175 s) for thigh muscle. The washout effect must be taken into account for the verification of treatment plans by means of positron camera measurements.

The authors produced the transparent color conversion thick film which is composed of a high concentration of YAG:Ce3+ nanoparticles prepared by glycothermal method, and characterized its optical properties. The transmittance of the 200μm thick film with the nanoparticle content 70.7wt% was 82% at 525nm corresponding to the emission peak of YAG:Ce3+. The intensity of photoluminescence due to the 5d→4f transition of Ce3+ in YAG:Ce3+ nanoparticles was doubled by placing a reflection mirror at the back of the transparent film. Judging from this result, the transparent film of YAG:Ce3+ nanoparticles has markedly low scattering loss.

Disulfide-bridged binuclear ruthenium complexes, [{RuCl(P(OMe) 3 ) 2 } 2 (µ-Cl) 2 (µ-S 2 )] ( 1), [{RuCl-(P(OMe) 3 ) 2 }(µ-Cl) 2 (µ-S 2 ){Ru(CH 3 CN)(P(OMe) 3 ) 2 ] + ([2] + ), [{Ru(CH 3 CN) , and [{Ru(CH 3 CN) 3 (P(OMe) 3 ) 2 } 2 (µ-S 2 )] 4+ ([5] 4+ ), have been synthesized, and their crystal structures have been solved. Compounds 1, [2] + , and [4] 2+ have a triply bridged Ru III (µ-Cl) 2 (µ-S 2 )Ru III core, in which the S 2 2ligand bridges the two Ru atoms in a cis configuration. Compounds [3] 3+ and [5] 4+ have a singly bridged trans-RuSSRu core, whereby [3] 3+ corresponds to a one-electron reduced form of [5] 4+ . Compound [3] 3+ is the first example of a well-characterized mixed-valent compound with a trans-MSSM core, where M is any metal. All the compounds have intense absorption bands at around 700 nm, which can be explained for [3] 3+ and [5] 4+ as a π-π* transition of the distinct trans-RuSSRu core. Resonance Raman spectroscopy of 1, [2] + , and [3] 3+ and comparison with several literature values for cis-RuSSRu compounds show that only [3] 3+ exhibits a strong ν(S-S) Raman band, when excited by λ e ) 647.1 nm, whereas all the others show strong to medium ν-(Ru-S) and very weak ν(S-S) bands. The ESR spectrum of [3] 3+ shows a rhombic signal with g 1 ) 2.12, g 2 ) 2.05, and g 3 ) 1.995. This anisotropy is unusually small, compared to most mononuclear and binuclear Ru(III) compounds with various ligands. Analysis of the g values by use of the matrix of spin-orbit coupling Hamiltonian has revealed a very small spin-orbit coupling constant of 100 cm -1 , which is a result of the extensive covalency of the metal-disulfide bond. The X-ray photoelectron spectrum of [3] 3+ did not give any of the expected double peaks of the Ru(II) and Ru(III) components; the observed peaks are Ru 3d 5/2 281.0 eV, 3P 3/2 462.4 eV, S(S 2 2-) 2P 3/2 162.7 eV. Compound [3] 3+ does not give any intervalence-transition band in the longer-wavelength visible to near-IR region, other than the UV-vis band similarly observed in the one-electron oxidized compound [5] 4+ . These characteristics are reasonably understood, if [3] 3+ is regarded as a mixed-valent complex with valence-averaged ground state (class III of the Robin and Day classification).