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High-speed photonic and electronic devices at present rely on radiofrequency electric fields to control the physical properties of a semiconductor, which limits their operating speed to terahertz frequencies (1012Hz; ref. ). Using the electric field from intense light pulses, however, could extend the operating frequency into the petahertz regime (1015Hz; ref. ). Here we demonstrate optical driving at a petahertz frequency in the wide-bandgap semiconductor gallium nitride. Few-cycle near-infrared pulses are shown to induce electric interband polarization though a multiphoton process. Dipole oscillations with a periodicity of 860 as are revealed in the gallium nitride electron and hole system by using the quantum interference between the two transitions from the valence and conduction band states, which are probed by an extremely short isolated attosecond pulse with a coherent broadband spectrum. In principle, this shows that the conductivity of the semiconductor can be manipulated on attosecond timescales, which corresponds to instantaneous light-induced switching from insulator to conductor. The resultant dipole frequency reaches 1.16 PHz, showing the potential for future high-speed signal processing technologies based on wide-bandgap semiconductors.

The standard diagnostic method for echinoderm microtubule-associated protein-like 4-anaplastic lymphoma receptor tyrosine kinase translocation is fluorescence in situ hybridization (FISH). Recently, immunohistochemistry (IHC) has been reported as a potential method in screening for anaplastic lymphoma kinase (ALK)-positive non–small-cell lung carcinomas (NSCLC), whereas several authors have reported a discordance between FISH and IHC results. We investigated the heterogeneity of ALKgene rearrangement in excision specimens by FISH and also examined whether the FISH score of ALKgene rearrangement corresponded in excision and biopsy samples from the same patient.

We demonstrate the spontaneous formation of spherical complex M12L24, which is composed of 12 palladium ions and 24 bidentate ligands, by molecular dynamics simulations. In contrast to our previous study on the smaller M6L8cage, we found that the larger M12L24self-assembly process involves noticeable kinetic trapping at lower nuclearity complexes, e.g., M6L12, M8L16, and M9L18. We also found that the kinetic trapping behaviors sensitively depend on the bend angle of ligands and the metal–ligand binding strength. Our results show that these kinetic effects, that have generally been neglected, are important factor in self-assembly structure determination of larger complexes as M12L24in this study.

The film boiling heat transfer around a vertical silver cylinder with a convex hemispherical bottom was investigated experimentally in quiescent water at atmospheric pressure. The experiments have been carried out using a quenching method. The diameter and length of the test cylinder are 32 mm and 48 mm, respectively. The test cylinder was heated to about 600 °C in an electric furnace and then cooled in saturated or subcooled water with an immersion depth of about 100 mm. The degree of liquid subcooling was varied from 0 K to 30 K. The analytical solutions for saturated and subcooled boiling are obtained by applying a two‐phase boundary layer theory for vapor film with a smooth interface. The experimental data correlates within ±15% based on the proposed prediction method. Also, the lower limit of film boiling was examined in terms of wall heat flux and degree of superheating. © 2010 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley InterScience (). DOI 10.1002/htj.20289

In an artificial biomineralization system, a polymer complex consisting of poly(vinyl alcohol) (PVA) and poly(acrylic acid) (PAA) was utilized as a mineralization field. The polymer complex was immersed in salt solution containing x mM CaCl2, 0.6x mM KH2PO4, and PAA at pH=7.4. After equilibrium was reached, the weight uptake in the polymer complex was determined in the dry state. When x was less than the transition concentration (xT), the polymer complex was transformed into a hydrogel, and the dry weight uptake gradually increased with increasing x. On the other hand, at x greater than xT, the polymer complex was transformed into an organic/inorganic solid composite, and the dry weight uptake was almost independent of x. The hydrogel formed was a hypercomplex gel composed of Ca2+and HPO42-ions and the polymer complex held together by hydrogen bonds and electrostatic interactions. The organic/inorganic solid composite appeared to be a solid solution of the polymer complex and hydroxyapatite, as indicated by experiments on the saturation state of the salt solutions. Our results indicate that the hypercomplex gel changed discontinuously to the organic/inorganic solid solution at x=xT; this discontinuity represents a phase transition of hypercomplex gel to organic/inorganic solid solution that is an open system whose border is permeable to both energy and mass. The hypercomplex gel and the organic/inorganic solid solution can serve as models for the fundamental structures of cartilaginous and skeletal material respectively.

Asymmetric amplification is a phenomenon in which the enantiomeric excess (ee) of a product is higher than that of a chiral auxiliary for a catalyst. We analyzed the mechanism of asymmetric amplification observed in the addition of diethylzinc (Et2Zn) to benzaldehyde (PhCHO) to synthesize 1‐phenyl‐1‐propanol in the presence of trans‐1,2‐diaminocyclohexane bistriflamide (DCBF) and titanium tetraisopropoxide (TIOP). In a manner similar to the reaction in which 1‐piperidino‐3,3‐dimethyl‐2‐butanol is a chiral auxiliary for the catalyst, when asymmetric amplification was observed, the ee of the product varied as the reaction progressed. The mechanisms of variation in ee in the two reactions, however, were different. No asymmetric amplification was observed when TIOP and PhCHO were added to a mixture of DCBF and Et2Zn, while the ee of the product was always higher than that of DCBF when PhCHO and Et2Zn were added to a mixture of DCBF and TIOP. In the latter case, the product ee decreased as the reaction progressed. The results indicate that DCBF forms inactive heterochiral complex causing an increase in the ee of DCBF in the solution, which is the chiral auxiliary for the catalyst. But the complex is not very stable and gradually dissociates due to the reaction with Et2Zn. As a result, the asymmetric amplification decreases as the reaction progresses. Chirality, 2008. © 2008 Wiley‐Liss, Inc.

CaCO3 was mineralized from solutions supersaturated only by poly(acrylic acid) (PAA), without bubbling any CO2 gas in the solution. For example, a layer of CaCO3 was built up on the surface of a chitosan membrane from a supersaturated aqueous solution containing CaCl2, Na2CO3, and PAA. In this newly developed method, the PAA alone suppresses the precipitation of CaCO3 from the bulk solution, and therefore, increases the supersaturated concentration. This concentration is estimated to be the same order as that attained in the method in which both CO2 gas and PAA were used. At the same time, PAA supplies nucleation fields by forming a polymer complex with chitosan. The crystal system obtained was different from those obtained when using CO2 gas. Self-organization of aragonite crystallites led to the formation of uniform, concentric, or branching patterns in the surface-domain structure. These patterns had morphologies similar to those discovered by other researchers, typically in the crystallization of ascorbic acid. Thicker layers of CaCO3 could be formed on chitosan membranes, the surfaces of which had been converted to a polyelectrolyte complex (PEC) by exposure to PAA solution before the onset of mineralization. Under certain conditions, the CaCO3 layer had a small spherical curvature, similar to a half-lens, and generated Newton's ring pattern from the interference fringes of visible light. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91:3627–3634, 2004

AbstractThe multilayers structures of silver nanoparticles passivated with a fatty acid are investigated by means of X-ray reflectivity (XR) measurement. A distinct “quasi-Bragg reflection” peak appears at the position corresponding to the layer distance. From the calculation, it is found that the layer distance is slightly smaller than the diameter of the nanoparticle.

Deuteranomaly, and to a lesser extent deuteranopia, are associated with a 5′ green‐red 3′ (G‐R) visual pigment hybrid gene. Such G‐R hybrid genes may also exist in males with normal color vision. This discrepancy can be explained if the position of the G‐R hybrid gene in the array determines the probability of its expression in the retina. In accord with our previous findings, we confirm that when a G‐R hybrid gene occupies the second position in the array, a deutan defect results (N= 2); whereas when a normal green pigment gene does, normal color vision ensues (N= 3). Regarding gene expression as a function of position in the array, in 5 postmortem retinae from individuals whose arrays contained one red and two green pigment genes that differed at a polymorphic site in exon 5, only the green pigment gene that occupied the second position in the array was expressed into retinal mRNA. In conclusion, our data suggest that only the first two genes in the X‐chromosome linked visual gene array are expressed in the retina and, therefore, influence the color vision phenotype. Green‐red hybrid genes cause deuteranomaly only if they occupy the second position in the array. © 2000 John Wiley & Sons, Inc. Col Res Appl, 26, S79–S83, 2001

Deuteranomaly, and to a lesser extent deuteranopia, are associated with a 5' green-red 3' (G-R) visual pigment hybrid gene. Such G-R hybrid genes may also exist in males with normal color vision. This discrepancy can be explained if the position of the G-R hybrid gene in the array determines the probability of its expression in the retina. In accord with our previous findings, we confirm that when a G-R hybrid gene occupies the second position in the array, a deutan defect results (N = 2); whereas when a normal green pigment gene does, normal color vision ensues (N = 3). Regarding gene expression as a function of position in the array, in 5 postmortem retinae from individuals whose arrays contained one red and two green pigment genes that differed at a polymorphic site in exon 5, only the green pigment gene that occupied the second position in the array was expressed into retinal mRNA. In conclusion, our data suggest that only the first two genes in the X-chromosome linked visual gene array are expressed in the retina and, therefore, influence the color vision phenotype. Green-red hybrid genes cause deuteranomaly only if they occupy the second position in the array. © 2000 John Wiley & Sons, Inc. Col Res Appl, 26, S79–S83, 2001

We report a novel "intelligent" gel that undergoes an autonomous swellingdeswelling oscillation without reliance on an alteration in external conditions. The mechanical oscillation in our gel system was produced via oscillating chemical reaction similar to metabolic reaction, called the Belousov-Zhabotinsky (BZ) reaction. We prepared gels composed of crosslinked Nisopropylacrylamide (NIPAAm) networks to which ruthenium tris(2,2'-bipyridine) (Ru(bpy)3), a catalyst for the BZ reaction, was covalently bonded. The BZ reaction occurring within the gel matrix generates periodic redox changes of the catalyst moiety: Ru(bpy)32+T Ru(bpy)33+. As a result, the gel exhibits a periodical swelling-deswelling change. When the gel size is smaller than the chemical wavelength, the redox change occurs homogeneously in the gel. In this case, the swelling-deswelling oscillation is isotropic and the chemical and mechanical oscillations are synchronized without a phase difference. In the case of a large rectangular gel, the total length of the gel periodically changes with the propagation of chemical waves. However, an "anti-phase mode" between the chemical and mechanical oscillations was observed. This phenomenon was explained by a theoretical model simulation. It has become apparent that a change in the overall gel length is equivalent to that in the last stationary wave at the free end. The dynamic behavior that locally shrunken (or swollen) parts propagate is similar to the peristaltic motion observed in worms.

The idea of stochastic resonance (SR) is extended to two-parameter dynamical systems based on the Oregonator model of the Belousov-Zhabotinsky (BZ) reaction. The first case presents the photosensitivity of the reaction, and light flux and a flow rate are the two control parameters. The second case presents the effect of temperature on the oscillatory behaviors, and temperature and a flow rate are the control parameters. Stochastic resonance is demonstrated in the first case in which a signal and noise are applied to the different inputs, respectively. The scenario and novel aspects of SR in two-parameter systems are discussed, and the possibility of the analogous SR in biological systems is also pointed out.

AbstractDispersion of silver nanoparticles was prepared from silver n-tetradecanoate via thermal decomposition. The absorption spectrum of the dispersion showed a broad band at ca. 420 nm, characteristic of plasmon in the silver nanoparticles. On the other hand, the nanoparticle monolayers both on water and on quartz had an absorption band at 470 nm, which coincided with the position of the reflection bands. Surface reflectance of the dispersion in toluene also had a broad band with a peak wavelength of 470 nm.

Oscillation of membrane potential across a tri-block copolypeptide membrane composed of (Glu)x-(Leu)y-(Glu)x(x = 0.18 and y = 0.64) was observed under an electrical current, when the membrane was placed between equimolar aqueous salt solutions. The amplitude of the oscillation was influenced by the type of cation and anion in the external salt solution, and the amplitude was in the sequence: K+>Na+>Cs+>Ca2+and Cl−>Br−. The frequencies of the oscillations were in the range 0.1 to 5 Hz, and were also slightly influenced by the type of cation and anion.

Differential transport of amino acids was examined through a polymer-supported liquid membrane containing a chiral crown ether, 2,3:4,5-bis[1,2-(3-phenylnaphtho)]-1,6,9,12,15,18-hexaoxacycloeicosa-2,4-diene. Enantiomer resolution ratio of 22.7 was obtained for Dl-phenylglycine. Differential uphill-transport was also achieved.

The rate of transport of L-leucine and L-tryptophan methyl esters through supported liquid membranes containing dibenzo-18-crown-6 and its acyl derivatives was measured. The amino ester competed with the coexisting sodium ion in membrane transport. In the case of lipophilic amino ester such as tryptophan methyl ester, the flux of sodium ion decreased. For the C3 to C8 acyl derivatives, no appreciable difference in flux of the amino ester was observed, whereas that of sodium ion revealed a minimum at the C4 derivative. In a high concentration region of the C8 derivative, the flux of leucine methyl ester remained constant.

AbstractSilver coating was examined on metal, glass and heatproof resins by using silver metallo-organic nanoparticles. An excellent silver-coated film was obtained by the low-temperature sintering at 300 °C or below. Utilization of the nanoparticle pastes for patterning in microelectronics is proposed.

AbstractSilver nanoparticles passivated with alkylate were formed via thermal decomposition of silver alkylates. The nanoparticles prepared from silver n-tetradecanoate were spread on the water surface, where they may move easily and thus expected to be arranged regular two-dimensional array. The properties and preparation conditions of the nanoparticle film were investigated by surface pressure - area isotherm and Brewster microscopic observation. The transmission electron micrographs of transferred film of the nanoparticles suggested that the nanoparticles distribute in the film regularly. Control of surface pressure enable us to form the C14-AgNP film with less defects on water surface.

The silver salts of fatty acids were thermally decomposed at 250°C in an atmosphere of nitrogen to form silver nanoparticles with a size of 5 nm. The particles suspended in toluene put on a hydrophilic surface of the plasma-polymerized film of osmium tetraoxide and on a water surface to form a two-dimensional array. The nanoparticles repelled each other with a distance of 2.8-3.5 nm depending on the length of the alkyl chain. The surface pressure-area isotherms were measured to confirm the condensation mechanism of two-dimensional arrangement of nano-particles surrounded by alkyl moieties.

A novel wave form of interfacial engine (a set of self-organized waves between two immiscible liquids) was observed by use of an aqueous solution of mixed surfactants (HTAB and dioctylsulfosuccinate).

Dynamic behavior of initially sessile droplets of oleic acid with sodium oleate was investigated in an aqueous buffer solution. The interface of droplet highly fluctuated at pH 9.0 and concomitantly grew a multilayered structure inside of the droplet. Volume change of the droplet suggested the existence of three independent mass-transport processes. This phenomenon was observed under specific conditions of pH and oil composition.