Preparation of [23]cyclophane-1,2-diones by the reaction of 3,6;12,15-Di-1,4-benzo[6.6](3,4)-1,2,5-thiadiazolocyclophanes with grignard reagents

3,6;12,15-Di-1,4-benzo[6.6](3,4)-1,2,5-thiadiazolocyclophanes 1a-c were prepared starting from 3,4-di-p-tolyl-1,2,5-thiadiazole 3 and converted into [2³]cyclophane-1,2-diones 2a-c by the reaction with Grignard reagents.     

Coherent oscillations in ultrafast fluorescence of photoactive yellow protein

The ultrafast photoinduced dynamics of photoactive yellow protein in aqueous solution were studied at room temperature by femtosecond fluorescence spectroscopy using an optical Kerr-gate technique. Coherent oscillations of the wave packet were directly observed in the two-dimensional time-energy map of ultrafast fluorescence with 180 fs time resolution and 5 nm spectral resolution. The two-dimensional map revealed that four or more oscillatory components exist within the broad bandwidth of the fluorescence spectrum, each of which is restricted in the respective narrow spectral region. Typical frequencies of the oscillatory modes are 50 and 120 cm(-1). In the landscape on the map, the oscillatory components were recognized as the ridges which were winding and descending with time. The amplitude of the oscillatory and winding behaviors is a few hundred cm(-1), which is the same order as the frequencies of the oscillations. The mean spectral positions of the oscillatory components in the two-dimensional map are well explained by considering the vibrational energies of intramolecular modes in the electronic ground state of the chromophore. The entire view of the wave packet oscillations and broadening in the electronic excited state, accompanied by fluorescence transitions to the vibrational sublevels belonging to the electronic ground state, was obtained.     

Ultrafast dynamics of photoactive yellow protein via the photoexcitation and emission processes

Pump-dump fluorescence spectroscopy was performed for photoactive yellow protein (PYP) at room temperature. The effect of the dump pulse on the population of the potential energy surface of the electronic excited state was examined as depletion in the stationary fluorescence intensity. The dynamic behavior of the population in the electronic excited state was successfully probed in the various combinations of the pump-dump delay, the dump-pulse wavelength, the dump-pulse energy and the observation wavelength. The experimental results were compared with the results obtained by the femtosecond time-resolved fluorescence spectroscopy.     

Novel combination of hydrophilic/hydrophobic surface for large wettability difference and its application to liquid manipulation

This paper reports a novel combination of hydrophilic/hydrophobic materials for the evolution of liquid manipulation. Droplet generation based on a hydrophilic/hydrophobic mechanism is a promising method for highly accurate liquid manipulations. Although several droplet manipulation devices utilizing hydrophilic/hydrophobic patterns have been reported, it has been difficult to split fluid into droplets solely through hydrophilic/hydrophobic patterns in a microchannel. In this study, a material combination for fabricating hydrophilic/hydrophobic patterns was investigated and their wettability difference was enhanced for droplet generation. To improve hydrophilicity, we attempted to increase the surface area of silicon oxide through pulsed plasma chemical vapor deposition (PPCVD). To improve hydrophobicity, the damage to the hydrophobic patterns in the fabrication process was reduced. We successfully enhanced the difference in contact angles from 54.3° to 86.6° by combining the developed hydrophilic material and hydrophobic material. The developed material combination could successfully split fluid into a quantitative droplet of 14.1 nL in a microfluidic chip. Because the developed hydrophilic/hydrophobic combination enables the formation of a droplet with desirable shape in microchannels, the developed hydrophilic/hydrophobic combination is a promising component for lab-on-a-chip applications.     

Simultaneous determination of serine enantiomers in plasma using Mosher's reagent and stable isotope dilution gas chromatography-mass spectrometry

D-Serine is a co-agonist of the N-methyl-D-aspartate receptor in glutamate neurotransmission and has been proposed as a potential therapeutic agent for schizophrenia. However, D-serine also acts as a nephrotoxic substance in rats at high doses. To investigate the pharmacokinetics and toxicokinetics of D-serine, a method for the stereoselective determination of serine enantiomers in rat plasma was developed using GC-MS with selected ion monitoring (GC-MS-SIM). DL-[(2)H(3)]Serine was used as an internal standard to account for losses associated with the extraction, derivatization and chromatography. Serine enantiomers were purified by cation-exchange chromatography using BondElut SCX cartridge and derivatized with HCl in methanol to form methyl ester followed by subsequent N,O-diacylation with optically active (+)-α-methoxy-α-trifluoromethylphenylacetyl chloride to form epimeric amide. Quantitation was performed by SIM of the molecular-related ions of the epimers in the chemical ionization mode. The intra- and inter-day reproducibility of the assay was less than 5% for D-serine and 3% for L-serine. The method was successively applied to study the pharmacokinetics of D-serine in rats.     

Compositeness Criteria of Particles in Quantum Field Theory and S-Matrix Theory

A review is given of recent developments in compositeness arguments of particles in the framework of Lagrangian field theory and S-matrix theory.