Ferroelectric Properties of (001)- and (106)-Oriented SrBi2Ta2O9 Epitaxial Thin Films

Epitaxially grown SrBi₂Ta₂O₉ (SBT) thin films with (001) and (106) orientations were prepared on La-doped SrTiO₃ (001) and (110) substrates, respectively, by coating-pyrolysis process. When the films were annealed in air, their epitaxy was poor and no significant difference was observed in the P-E characteristics for the films that have different orientations. By contrast, the crystallinity and epitaxy of the films increased with decreasing oxygen partial pressure, p(O₂), of annealing atmosphere. Using these high quality epitaxial films, we observed a distinct difference in P-E hysteresis curves, which reflects the orientation of the films. After postannealing of these films in O₂ to compensate for possible oxygen deficiency, which might have been introduced into the SBT films owing to low p(O₂) annealing, the anisotropy of the ferroelectric response was maintained and almost the same P-E loops were obtained.     

Bishordeninyl Terpene Alkaloids from Zanthoxylum Integrifoliolum

Examination of the leaves of Zanthoxylum integrifoliolum led to the isolation of a new bishordeninyl alkaloid, integramine, along with alfileramine, α‐allocryptopine, pseudoprotopine and (+)‐sesamin from the tertiary non‐phenolic base fraction. The structures of these compounds were elucidated by spectral evidence.     

Visible light induced oxygenation of cyclohexene with activation of water sensitized by dihydroxy coordinated tetraphenyloprphyrinatotin(IV)

Visible light irradiation of a reaction mixture containing dihydroxy coordinated tetraphenylporphyrinatotin(IV), cyclohexene and potassium hexachloroplatinate induced oxygenation of the cyclohexene under degassed conditions. In the reaction system, a water molecule served as the oxygen donor. Cyclohex-2-enol, 1,2-dichlorocyclohexane and 2-chlorocyclohexanol were the major oxidation products and the quantum yield was around 0.1. An experiment using H₂ ¹⁸O revealed that an ¹⁸O atom was quantitatively incorporated into the oxygenated products. The reaction was initially induced by an electron transfer from an excited triplet porphyrin to potassium hexachloroplatinate producing a cation radical of the porphyrin. Metal-oxo type complexes formed through deprotonation of the hydroxy group of the porphyrin cation radical were key reactive intermediates reacting with cyclohexene. Two kinds of the metal-oxo type complex reactive intermediate were kinetically demonstrated to be involved in the reaction system, producing different oxidation products from cyclohexene.     

Visualized single cell dynamics and analysis of molecular tricks

The dynamic behaviours of various cells were analysed by video-microscopes and mass spectrometers at the single-cell level. By the video image analysis of a single cell, real dynamic moments of cell behaviour, which were previously accessible only to the imagination, can be visualized — such as the popping of micro-granules, and the exocytosis of neutrophils; a mast cell model cell line, RBL-2H3 cells, and pancreatic beta cell model cell line, MIN-6. In combination with the observations of behaviour, more direct molecular analyses become much more important for showing the molecular interplay in a cell. The combination of mass spectrometries was applied to analysis at the single cellular level. Based on the current progress in these analyses, the future trends in analyses of single cellular dynamism are predicted.     

Synthesis and anti-tumor activity of a fluorinated analog of medroxyprogesterone acetate (MPA), 9alpha-fluoromedroxyprogesterone acetate (FMPA)

We synthesized 9alpha-fluoromedroxyprogesterone acetate (FMPA) in order to test whether it is a more potent anti-angiogenic agent than medroxyprogesterone acetate (MPA), which has been widely used as a therapeutic agent for breast and endometrium cancers. FMPA was previously synthesized in 10 steps (total yield: 1%). An efficient synthesis of FMPA has been achieved in 6 steps (total yield: 12%). We examined the anti-tumor effect of FMPA, complexed with dimethyl-beta-cyclodextrin (DM-beta-CyD), on rat mammary carcinomas induced by 7,12-dimethylbenz[a]anthracene (DMBA). FMPA showed great anti-tumor effect on DMBA-induced rat mammary carcinomas.     

One-step preparation of positively-charged gold nanoraspberry

Self-assembling particles were prepared by a new synthetic strategy for a raspberry-like aggregate, based on three-dimensional particle-aniline oligomer-particle repeated sequences; this one-step process, without the need for extra control, organic solvents, or ligand exchange, could further help in the realization of nanoscale electronics and molecular devices.     

Photochemical asymmetric synthesis of phenyl-bearing quaternary chiral carbons using chiral-memory effect on beta-hydrogen abstraction by thiocarbonyl group

Quaternary chiral carbons were effectively generated from tertiary chiral carbons via photochemical intramolecular beta-hydrogen abstraction reaction of thioimides involving the highly-controlled chiral-memory effect.     

Palladium-catalyzed sonogashira and hiyama reactions using phosphine-free hydrazone ligands

Palladium/copper-catalyzed Sonogashira cross-coupling reaction of aryl halides with a variety of terminal alkynes under amine-free conditions in dimethylformamide (DMF) at 80 degrees C gave internal arylated alkynes using PdCl2(MeCN)2 with phosphine-free hydrazone 2a as a ligand and CuI as the cocatalyst in good yields. We also found PdCl2/hydrazone ligand 1d in PhMe at 80 degrees C was a phosphine-free efficient catalyst system for a Hiyama cross-coupling reaction of aryl bromides with aryl(trialkoxy)silanes in good yields.     

Highly stereoselective TiCl4-Catalyzed Evans-aldol and Et3Al-mediated Reformatsky reactions. Efficient accesses to optically active syn- or anti-alpha-trifluoromethyl-beta-hydroxy carboxylic acid derivatives

[reaction: see text] The TiCl(4)-catalyzed Evans-aldol reaction of optically active 3,3,3-trifluoropropanoic imide gave the non-Evans syn product stereoselectively, whereas the Reformatsky reaction of 2-bromo-3,3,3-trifluoropropanoic imide in the presence of Et(3)Al led to the Evans anti product. These new approaches enabled us to synthesize all stereoisomers of trifluoromethylated aldol products for the first time.     

Self-assembling of n-type semiconductor tri(phenanthrolino)hexaazatriphenylenes with a large aromatic core

[reaction: see text] Large disk-shaped aromatic tri(phenanthrolino)hexaazatriphenylenes 5a, 5b, and 5c with six butyl, dodecyl, and 4-octylphenyl groups, respectively, were self-assembled both in solution and film state to form one-dimensional aggregates. Their n-type semiconducting nature was indicated from CV measurement, in which the first reduction potentials were evaluated at around -1.7 V (vs Fc/Fc(+)) in dichloromethane.