Adsorption behavior of cytochrome c, myoglobin and hemoglobin in a quartz surface probed using slab optical waveguide (SOWG) spectroscopy.

Slab optical waveguide (SOWG) spectroscopy was used to observe the adsorption behavior of three important heme proteins, namely cytochrome c, myoglobin and hemoglobin, in a quartz surface. Using prism-coupled polychromatic visible light propagated into a quartz waveguide by internal total reflection, the real-time monitoring of evanescent wave absorption revealed a strong dependence of the protein-surface interaction on the protein concentration, the solution pH and the ionic strength. For the three proteins studied, the absorbance-bulk concentration ratio was higher at low bulk concentrations, and decreased at higher concentrations. For cytochrome c and myoglobin, the absorbance approached a limiting value, but buffered hemoglobin surprisingly did not show any indication of forming a signal plateau. Moreover, the slow introduction of protein into the solution lessened the total adsorbed amount per unit area. These observations suggested a possible conformational transition of the protein molecules at the quartz surface after adsorption. For a bulkier protein, hemoglobin, adsorption onto the quartz surface was enhanced in the presence of a phosphate buffer, while the opposite effect was observed for the smaller cytochrome c and myoglobin molecules. The results of pH studies concurred with the electrostatic interactions predicted from the isoelectric data of proteins and the quartz surface.     

Low-Driving-Voltage Optical Modulation Utilizing FWM for High-Speed Transmission Systems

We propose an optical transmitter with reduced modulator driving voltage. This reduction is achieved through an on-off ratio improvement technique based on FWM. We confirmed the feasibility of the method in a 43-Gbit/s experiment.     

High-spin states and signature inversion in odd-odd182Au

High-spin states in¹⁸²Au have been produced and studied via the¹⁵²Sm(³⁵Cl,5nγ)¹⁸²Au reaction. The level scheme consisting of the πh _9/2⊗νi _13/2 and πi _13/2⊗νi _13/2 bands has been established for the first time. The low spin signature inversion in both bands has been found. The observed signature inversion phenomena can be interpreted qualitatively using the pairing and deformation self-consistent cranked Wood-Saxon calculations.     

Encapsulation of atomic hydrogen into silsesquioxane cages and ESR of encapsulated hydrogen atoms

Hydrogen atoms are encapsulated in octasilsesquioxane, R(SiO_1.5)₈, by irradiation with γ-rays at room temperature. In deca- and dodecasilsesquioxane, hydrogen atoms are encapsulated by irradiation at 77 K. The thermal decay of the encapsulated hydrogen is well described by a single-exponential function. The excitation energies of the decay are 110–117, 50.4, and 55.6 kJ/mol for the hydrogen atoms in Q₈M₈, Q₁₀M₁₀, and Q₁₂M₁₂, respectively. Theg-values and hyperfine splitting (hfs) constants of the hydrogen atoms in R(SiO_1.5)₈ are dependent on the substituents in the corners of the polyhedra, R. Theg-values are independent of the temperatures, while the hfs constants increase as the temperature decreases. Theg-values of the hydrogen atoms in a large encapsulating cavity decrease with increasing cavity size and approach 2.0023. The temperature dependence of the hfs constants for the hydrogen atoms in Q₁₀M₁₀ or Q₁₂M₁₂ suggests that the hydrogen atoms are localized within the encapsulating cages at low temperatures.     

Improvement in reliability of probabilistic test of significant differences in GeneChip experiments.

A probabilistic test (FUMI theory) for GeneChip experiments has been proposed for selecting the genes which show significant differences in the gene expression levels between a single pair of treatment and control. This paper describes that the reliability of the judgment by the FUMI theory can be enhanced, when the selected genes are referred to biomolecular-functional networks of a commercial database. The genes judged as being differently expressed are grouped into a cluster in the biomolecular networks. It is also demonstrated that false positive genes have a trend in the networks to be isolated from each other, and also away from the clustered genes, since the false positive genes are randomly selected.     

Optical Differentiation Phase Measurement Using the Bias Shifting Method

A new optical phase measurement method using a differentiation filter is proposed. The new method uses two images obtained by shifting the filter. This method has an advantage in that non-uniformity of the wavefront intensity does not produce errors. We present herein the theory of the newly proposed method and verify the theory by computer simulation. The effects of non-uniformity of the wavefront intensity, noise, and bias shifting length for errors are discussed. The system has been demonstrated for a plane wave and a spherical wave. For the proposed method, although the number of errors due to noise increases, the number of errors due to non-uniformity decreases. Therefore, the proposed method is useful for the phase measurement of a wavefront for which the intensity is not uniform. In addition, it improves the accuracy of the phase measurement system using a differentiation filter.     

Formation of Anatase Nanocrystals-Precipitated Silica Coatings on Plastic Substrates by the Sol-Gel Process with Hot Water Treatment

Anatase nanocrystals-precipitated silica coatings were formed on plastic substrates such as poly(ethylene terephtalate) (PET), acrylic resin (AC) and polycarbonate (PC) from silica-titania gel coatings with and without addition of poly(ethylene glycol) (PEG) by hot water treatment. The maximum thickness of the coatings which can be formed without cracking or peeling-off was 100 to 200 nm for PET and PC substrates, whereas it was less than 50 nm for AC substrates. After a hot water treatment at 90°C for 120 min, the size of the anatase nanocrystals increased to be 30 and 50 nm for the coatings obtained with and without PEG, respectively. Anatase nanocrystals were formed throughout the whole of the coatings obtained with PEG and were formed only on the surface of the coatings obtained without PEG. Both coatings obtained with and without PEG were highly transparent. The plastic substrates with coatings obtained without PEG showed good weathering resistance owing to the protective effects of the residual silica under-layer. The coatings obtained with PEG showed higher photocatalytic activities than those obtained without PEG due to smaller size and higher dispersion of anatase nanocrystals in the coatings.     

Synthesis and lyotropic liquid crystal properties of chiral helical polycarbodiimides

Chiral helical polymers have been expected to exhibit optical activity with a significantly large optical rotation power. In this paper polymethylphenylethylcarbodiimides (Poly-PhEMCDI) with helical structure were synthesized by the insertion polymerization of a corresponding chiral monomeric carbodiimide initiated by a copper complex. The circular dichroism spectra and optical rotation power induced by the ordered rigid main chain helical structure of polycarbodiimides, in solution and as cast films, were studied. Polycarbodiimides have a rigid rod helical structure and form lyotropic liquid crystal (LLC) in organic solvents such as dichloromethane (DCM), chloroform and THF. The LLC phase was studied using polarizing optical microscopy and X-ray diffraction. A chiral nematic phase was formed in DCM and chloroform in the concentration range 20-36%. Spherulites were formed in more concentrated solution. The formation of a LLC phase in polycarbodiimides organic solutions makes it possible to align the polymer helical chain to form an ordered film for electro-optical applications.     

Sensing phenothiazine drugs at a gold electrode co-modified with DNA and gold nanoparticles.

DNA and gold nanoparticles are co-immobilized at a gold electrode through elaborate self-assembly processes. This configuration has proven to be useful as a sensor for phenothiazine drugs, taking advantage of the well-known, relatively large surface area of gold nanoparticles and the strong intercalation between dsDNA and phenothiazine drugs. This modified electrode has demonstrated good sensitivity and stability towards the oxidation of two model phenothiazine drugs: promethazine and chlorpromazine. A linear dependence between the concentration of phenothiazine drugs and the peak current is observed, with a concentration range of 2.0 x 10(-5)-1.6 x 10(-4) M and 1.0 x 10(-5)-1.2 x 10(-4) M, and a detection limit of 1.0 x 10(-5) M and 7.0 x 10(-6) M, for promethazine and chlorpromazine, respectively.     

High-spin states in 61Cu

The study of high spin states in ¹⁰⁰Pd has indicated the presence of both single particle and collective states. More than twenty new transitions have been observed. A substantial modification and extension of the existing level scheme is proposed. The negative parity states can be understood in terms of collective excitations of the core coupled to the 9^? and 5^? bandheads, which are probably based upon two quasineutron ν(h_11/2,g_7/2) and two quasiproton π(g_9/2,p_1/2) configurations respectively.