Phase rotation scheme of laser-produced ions for reduction of the energy spread

In order to widely spread out particle beams utilized in cancer therapy, laser-produced ions are developed as the injection beam for an ion synchrotron dedicated for cancer therapy. Such a laser ion source is expected to contribute largely to the realization of compactness of the size and low cost of the cancer therapy accelerator. The energy spectrum of the laser-produced ions, however, has no peak, but their intensities decrease exponentially according to the increase of the energy. For the purpose of modifying such a situation, we have proposed a scheme to rotate the beam in the longitudinal phase space with the use of the RF electric field, which is phase-adjusted with the pulse laser. We aim for a reduction of the energy spread of ± 5% selected by an energy analyzer and slits to ±1% by such phase rotation. For this purpose, a quarter wavelength resonator with two gaps with the same resonant frequency as the source laser has already been fabricated, together with its RF power source. The above phase rotation system and its recent experimental realization are presented.     

Palladium-Catalyzed Buchwald-Hartwig Type Amination of Fluorous Arylsulfonates

Palladium-catalyzed cross-coupling reactions of aryl perfluorooctanesulfonates with amines are introduced. Application of the fluorous tag in multistep synthesis of triaryl-substituted pyrimidine is also described.     

Development of a Millimeter Wave Compact Equipment for NDT of Materials

We developed a compact equipment working at 94 GHz to replace the commonly used network analyzer for nondestructive testing of materials. The compact equipment was designed to measure the variations in the amplitude and phase of the reflected signal from the material relative to a reference signal. A good accuracy of the amplitude and phase measurement of the equipment was obtained in the confirmative experiments. The distribution of a drop of water in a wood plate is clearly visible in the millimeter wave images obtained by the amplitude and phase measurement.     

Semiempirical calculation of electronic spectra of organic compounds by using the improved method of new-γ electron repulsion integral. Part 2. Polycyclic aromatic hydrocarbons (PAHs)

Excitation energies of 123 polycyclic aromatic hydrocarbons were calculated by incorporating the improved method of new-γ for the two-center electron repulsion integral into two semiempirical molecular orbital methods (CNDO/S and INDO/S). This variable method well reproduced experimental excitation energies of them. The average error of the improvement is about 0.162 (CNDO/S) or 0.237 eV (INDO/S) though the average error without the improvement is about 0.541 (CNDO/S) or 0.536 eV (INDO/S). The improvement was useful for the calculations of other organic compounds including hetero atoms, such as organic dye.     

Crystal structures of n-alkanes with branches of different size in the middle

We synthesized four branched n-alkane samples C35-C1, C35-C4, C35-C6, and C35-C4Ph with the same number of carbons as the main chain, n = 35, to which the methyl, butyl, hexyl, and butyl phenyl groups were respectively attached at the middle, and also the corresponding linear homologue of C35, and studied their crystalline structures from DSC, IR, and Raman spectroscopy, X-ray diffraction measurement, and computer simulation. Solid-solid phase transitions characteristic of linear alkane C35 are not observed for any branched alkanes, and their melting temperatures Tm are lowered to 325.2, 318.5, 314.3, and 314.1K, respectively. Main chains of branched alkane molecules are not folded, irrespective of length and chemical structure of branches, but are extended to take the planar zigzag form in the solid state. The branches of C35-C4 and C35-C6 are also aligned inside the crystal in the extended form. Data analyses on solution-grown crystallized samples reveal that, with increasing the branch length, their crystal structures transform from polymorphic forms of the orthorhombic (P2(1)2(1)2(1)) and the triclinic (P) for C35-C1 and C35-C4 to the unique triclinic form for C35-C6 and C35-C4Ph, so as to minimize extra surface energy invoked by introduction of long branches.     

Effect of equimolar salt to decyltrimethylammonium decyl sulfate on vesicle formation and surface adsorption

The aqueous solution of mixture of sodium decyl sulfate (SDeS) and decyltrimethylammonium bromide (DeTAB) has been found to form equilibrium multilamellar vesicles (MLV) spontaneously. We measured the surface tension of the aqueous solution of 1:1 mixture of SDeS and DeTAB as a function of temperature T at various molalities m under atmospheric pressure. The surface density, the entropy of adsorption and the entropy of vesicle formation are evaluated and compared with those of the decyltrimethylammonium decyl sulfate (DeTADeS) aqueous solution system to investigate the role of small counterions in the mechanism of equilibrium vesicle formation. The saturated surface density Gamma (H,C ) vs T curve of the SDeS/DeTAB system sits below that of the DeTADeS system. Therefore, sodium and bromide ions are negatively adsorbed and nevertheless, they neutralize the electric charge of the decyl sulfate ion DeS(-) and the decyltrimethylammonium ion DeTA(+) to some extent to weaken the electrostatic attraction between the polar head groups in the adsorbed film. The net surfactant concentration required for vesicle formation was larger in the SDeS/DeTAB system. Hence, the electrostatic attraction between the polar head groups of the surfactant ions which is one of the major driving forces for vesicle formation is weakened by the presence of the counterions Na(+) and Br(-). Small but distinct changes in the surface density and the entropies of MLV formation of the SDeS/DeTAB system from those of the DeTADeS system were also found.     

Evaluation of thallium-201 myocardial emission computed tomography based on a comparison with postmortem findings

The correlative study of myocardial perfusion assessed by 201Tl myocardial ECT with the pathological finding of the heart was performed in 10 autopsied cases with mean age of 77 years old (range: 60-90 y). In 6 cases with myocardial infarction (MI) 7 perfusion defects were observed, that was, 3 in anteroseptal wall, 1 in anterolateral wall and 3 in posterior wall on the images of SPECT. Seven MIs were also found in postmortem examination. Six MIs were observed at autopsy corresponding to perfusion defect on SPECT images. In one myocardial perfusion defect at inferoposterior portion on SPECT, a non-transmural MI was found at anteroseptum. In one case with valvular disease a false positive result was obtained at posterior wall where neither myocardial necrosis nor fibrosis was observed at autopsy. This case had aortic stenosis due to bicuspid aortic valve by autopsy. The ventricle was divided into 16 segments in each of 4 short axial images to evaluate extent of MI. SPECT for extent of MI showed sensitivity of 81.9%, specificity of 96.0% and diagnostic accuracy of 92.5%. False negative segment was apt to be observed at the surrounding of non-transmural MI or basal half of left ventricle (LV) with transmural MI, while false positive segment was at posterior portion of basal half of LV. It was concluded that myocardial ECT was useful for evaluation of the site and extent of MI.     

Hexanuclear Pt complexes composed of two cyclic triplatinum units connected with 1,4-diphenylene and 1,1′-ferrocenylene spacer

1,4-Bis(dimethylsilyl)benzene reacted with [Pt₃H(PEt₃)₃(μ-PPh₂)₃] at room temperature to yield trinuclear Pt complex [Pt₃(SiMe₂C₆H₄SiMe₂H)(PEt₃)₂(μ-PPh₂)₃] (1a). Heating a solution containing an equimolar mixture of [Pt₃H(PEt₃)₃(μ-PPh₂)₃] and 1a at 60 °C produced a hexanuclear Pt complex [(PEt₃)₂(μ-PPh₂)₃Pt₃(SiMe₂C₆H₄SiMe₂)Pt₃(PEt₃)₂(μ-PPh₂)₃] (2a). Complex 1a was characterized by X-ray crystallography and NMR spectroscopy, while the structure of 2a was determined by X-ray crystallography of single crystals containing 2a and [Pt₃H₂(PEt₃)₂(μ-PPh₂)₄] in 1:1 ratio. [Pt₃(SiMe₂fcSiMe₂H)(PEt₃)₂(μ-PPh₂)₃] (fc = Fe(η⁵-C₅H₄)₂) (1b) and [(PEt₃)₂(μ-PPh₂)₃Pt₃(SiMe₂fcSiMe₂)Pt₃(PEt₃)₂(μ-PPh₂)₃] (2b) were obtained similarly from the reactions of 1,1′-bis(dimethylsilyl)ferrocene with [Pt₃H(PEt₃)₃(μ-PPh₂)₃] and characterized by NMR spectroscopy and elemental analyses.