Revisit the classical theories of the conductance of unassociated electrolytes. Is there reality in relaxation?

The experimental results of the ionic conductance of the electrolytic solution can be explained without the use of relaxation until almost 2M concentration of the NaCl solution within 97% agreement with two parameters: the hydrated ion radii for cations and anions. No other fitting parameters were introduced, and no ion association was assumed. The theory is based on a newly introduced electrochemical potential that incorporates the interaction between ions and fluctuations in electrolyte concentration in the nanosized region.

Contribution of adenosine to the increase in skeletal muscle blood flow caused by manual acupuncture in rats.

Background And Aim: Adenosine is believed to play an important role in local acupuncture analgesia. The aim of this study was to investigate the contribution of adenosine to the increase in skeletal muscle blood flow (MBF) caused by manual acupuncture (MA).

Methods: Thirty-two male Sprague-Dawley rats (310-360 g) were anaesthetised and divided into four equal groups (n=8 each): Saline, Saline+MA, Theophylline, and Theophylline+MA.

Contributions of nitric oxide and prostaglandins to the local increase in muscle blood flow following manual acupuncture in rats.

Objective: To investigate the contributions of nitric oxide (NO) and prostaglandins (PGs) to the increase in local muscle blood flow (MBF) observed following manual acupuncture (MA).

Methods: Male Sprague-Dawley rats (n=112; 250-310 g) were injected intraperitoneally with a non-selective NO synthase inhibitor (NG-nitro-L-arginine methyl ester hydrochloride: L-NAME; 10, 50 or 500 mg/kg), a non-selective cyclo-oxygenase inhibitor (indomethacin; 10, 50 or 500 mg/kg), a combination of L-NAME and indomethacin (500 mg/kg each) or saline only under urethane anaesthesia (1.2 g/kg).

Measurement of the index of refraction of μm crystals by a confocal laser microscope--potential application for the refractive index mapping of μm scale.

A conventional laser microscope can be used to derive the index of refractivity by the ratio of geometrical height of the transparent platelet to the apparent height of the normal incident light for very small crystals in the wide size range. We demonstrate that the simple method is effective for the samples from 100 μm to 16 μm in size using alkali halide crystals as a model system. The method is also applied for the surface fractured micro-crystals and an inclined crystal with microscopic size regime.

Participation of calcitonin gene related peptide released via axon reflex in the local increase in muscle blood flow following manual acupuncture.

Objective: The purpose of this study was to determine how calcitonin gene related peptide (CGRP) via axon reflex participates in increasing local muscle blood flow (MBF) following manual acupuncture (MA).

Methods: Male Sprague-Dawley rats (N=56, 270-350 g) were used. We examined (1) the effects of MA on MBF in the tibialis anterior (TA) muscle in normal rats; (2) the effects of MA on MBF in the TA injected with saline or hCGRP8-37 (low: 2×10(-4) mol/litre; high: 2×10(-3) mol/litre), a competitive CGRP receptor antagonist, in rats; and (3) the effects of MA on MBF in the TA in capsaicin-treated rats.

Functional noble metal nanoparticle superlattices grown at interfaces.

Nanoparticle crystals or superlattices (SLs) are three dimensional arrangements of nanoparticles in the micrometre regime. In SLs, the particles are periodically arranged in a coherent long range order and hence they show collective properties. Various spectroscopic, scattering and imaging techniques have been used to understand the structure of self-assembled SLs.

Organic mediator-induced structural transformation in superlattices of monolayer-protected gold nanoparticles.

N-acetylglutathione (NAG)-protected gold nanoparticles self-assemble into three-dimensional (3D) face-centered cubic (fcc)-type superlattices at an air/water interface under highly acidic conditions. To prepare the well-defined superlattices, 1month's incubation is at least necessary since the size growth of the as-prepared nanoparticles is essential. Addition of 4-pyridinecarboxyic acid (PyC), a bifunctional hydrogen-bonding mediator, promotes the formation of the superlattices, which are created for about 2weeks' storage.

Temperature dependence on the charge transport behaviour of 3-D superlattice crystals of mercaptosuccinic acid-protected gold nanoparticles.

The electric charge transport behavior of a random assembly of three-dimensional superlattice crystals (having different core sizes) of mercaptosuccinic acid-protected gold nanoparticles showed a unique behavior of metallic-like nature at low temperatures and semiconductor nature at high temperatures in addition to a reversible transition feature in the hopping region.

Charge transport behavior of N-(2-Mercaptopropionyl glycine)-protected gold clusters with temperature.

N-(2-Mercaptopropionyl glycine)-passivated gold clusters (Au-MPG) represent a unique networked system of monolayer-protected clusters (MPCs) due to inter- and/or intramolecular hydrogen bonding between the MPC units thanks to the terminal carboxylic acid groups of the monolayers. We have investigated the size-dependent electric charge transport in well-dried thin films of Au-MPG MPCs by a four-probe methodology as a function of temperature. The MPCs display a novel behavior of metallic-like-to-semiconductor crossover with increase of temperature.

Organic styryl dye nanoparticles: synthesis and unique spectroscopic properties.

We report the synthesis and unique spectroscopic properties of organic styryl dye nanoparticles. Aqueous-phase ion association between a cationic styryl dye 2-(4-(dimethylamino)styryl)-1-ethylpyridinium (DASPE), possessing both electron donor and acceptor groups in its molecule, and tetraphenylborate (TPB) or tetrakis(4-fluorophenyl)borate (TFPB) anion, in the presence of poly(vinylpyrrolidone), produces the ion-based dye (DASPE) nanoparticles of approximately 30-100 nm in diameter. Absorption spectra of the DASPE nanoparticles show a large bathochromic shift in comparison with that of the dye monomer in water.

Investigation of charge transport in mercaptosuccinic acid-passivated gold clusters.

Investigation of electric charge transport in well-dried thin films of mercaptosuccinic acid-protected gold clusters having different cluster core sizes by a four-probe methodology revealed a novel behavior of metalliclike to semiconductor crossover with an increase in temperature. The systems were found comprising of minor metallic and major insulating networks. At low temperatures, the monolayer-protected clusters (MPCs) were found to show a metalliclike nature with a linear increase in resistivity with an increase in temperature.

Chiral functionalization of optically inactive monolayer-protected silver nanoclusters by chiral ligand-exchange reactions.

We report the ligand-exchange reaction between the optically inactive racemic penicillamine monolayer on a silver nanocluster surface and enantiopure D- or L-penicillamine dissolved in solution. Emergence of the identical band positions in the gel electrophoresis separation assures the presence of size-invariant silver nanoclusters (1.05 and 1.

Quantitative analysis of the relation between soft tissue stiffness palpated from the body surface and tissue hemodynamics in the human forearm.

We investigated the quantitative relation between soft tissue stiffness palpated from the body surface and hemodynamics in the human forearm. We examined the relation between pressures and blood flow in both the main artery and vein measured by magnetic resonance imaging (MRI), the cross-sectional area of forearm measured by MRI and soft tissue stiffness. Six male volunteers participated.

Surface charge driven size evolution during the formation of self-assembled nanostructures from discrete hydrophilic silver nanoparticles.

We investigate the spontaneous evolution of mercaptosuccinic acid-capped silver nanoparticles (MSA-Ag) of size 2.5 ± 1.0 nm during the formation of assembled nanostructures at the air/water interface.

Chemometric and microscopic analyses for the size growth of monolayer-protected gold nanoparticles during their superlattice formation.

Superlattices of gold nanoparticles have been produced at an air/solution interface under a highly acidic condition. The nanoparticle surface is protected by N-acetylglutathione (NAG). During the course of the superlattice formation, size growth of nanoparticles was observed: The superlattices were composed of nanoparticles of 6.

Effect of organic solvents on J aggregation of pseudoisocyanine dye at mica/water interfaces: morphological transition from three-dimension to two-dimension.

Morphological and spectroscopic properties of pseudoisocyanine (PIC) J aggregates produced at mica/solution interfaces have been characterized by absorption/fluorescence spectroscopy, fluorescence microscopy, and atomic force microscopy. Addition of organic solvents (1-propanol (PrOH) or 1,4-dioxane (Dox)) into aqueous solutions of the PIC dye induced a transition of the morphology of the interfacial J aggregates. The characteristic feature of this transition is the thickness (or height) change of the aggregate domain layers from three-dimensions to two-dimensions: The domain area of the J aggregates was dependent on the amount of the organic cosolvent, while the domain thickness was dependent on the type of the cosolvent.

Electrolyte-induced mesoscopic aggregation of thiacarbocyanine dye in aqueous solution: counterion size specificity.

Countercation size specificity is presented for the electrolyte-induced aggregation of 3,3'-disulfopropyl-5,5'-dichloro-9-methyl thiacarbocyanine (TCC) dye in aqueous solution. Addition of electrolytes having a small monovalent cation (Na+, NH4+, or Cs+) induced pure H aggregates of TCC, whereas J aggregates were preferentially promoted by electrolytes with a large monovalent cation ([N(CH3)4]+ or [N(C2H5)4]+). The electrolyte-induced H aggregate (HS aggregate) differed spectroscopically from that spontaneously self-assembled in aqueous solution.

Self-assembly of acridine orange dye at a mica/solution interface: formation of nanostripe supramolecular architectures.

Optical waveguide spectroscopy and atomic force microscopy (AFM) have been used to characterize the supramolecular architectures of acridine orange (AO) dye self-assembled at a mica/aqueous solution interface. Under the saturated adsorption conditions, optical waveguide spectroscopy revealed that the dye formed H-type aggregates at the interface. In situ AFM visualized interesting morphology of the dye aggregates showing nanosized meandering stripes with the width of approximately 1.

Highly ordered superlattices from polydisperse Ag nanoparticles: a comparative study of fractionation and self-correction.

We have examined two different routes to construct highly ordered two- or three-dimensional (2D or 3D) superlattice structures from hydrophilic polydisperse mercaptosuccinic acid (MSA)-modified Ag nanoparticles of the average size of 2.5 nm. First, polydisperse particles were fractionized by the polyacrylamide gel electrophoresis (PAGE) method.

Fivefold symmetry in superlattices of monolayer-protected gold nanoparticles.

Three-dimensional (3D) superlattices of gold nanoparticles were prepared at an air/solution interface. The surface of the gold nanoparticles used is protected by N-acetylglutathione (NAG). Morphological studies revealed that the superlattices formed fivefold symmetric structures such as pentagonal rod, decahedron, and icosahedron, which were probably developed by multiple twinning.

Kinetic stabilization of growing gold clusters by passivation with thiolates.

Small gold clusters (<1 nm), protected by monolayers of glutathione, N-(2-mercaptopropionyl)glycine, or mercaptosuccinic acid, were prepared by reducing the corresponding Au(I)-thiolate polymers and were fractionated by size using polyacrylamide gel electrophoresis (PAGE). Mass analysis of the fractionated clusters revealed that their core sizes varied with the molecular structures of the thiolates. This finding indicates that the reduction of the Au(I)-thiolate polymers yields small clusters whose growth is kinetically hindered by passivation with thiolates.

Large optical activity of gold nanocluster enantiomers induced by a pair of optically active penicillamines.

We have succeeded for the first time in preparing a pair of gold nanocluster enantiomers protected by optically active thiols: D- and L-penicillamine (D-Pen and L-Pen). Circular dichroism (CD) spectroscopy confirmed the mirror image relationship between the D-Pen-capped and the L-Pen-capped gold nanoclusters, suggesting that the surface modifier acts as a chiral selector, and that the nanoclusters have well-defined stereostructures as common chiral molecules do. No CD signals could be obtained when the gold nanoclusters were synthesized by using a racemic mixture (rac-Pen).

Synthesis of silicon nanowires and nanoparticles by arc-discharge in water.

Si nanowires of diameters 5-20 nm and nanoparticles of approximately 4 nm were synthesized by a simple arc-discharge method in water. The TEM analysis reveals that the growth direction of the observed Si nanowires is parallel to the {111} crystal planes.

Synthesis of luminescent silicon nanopowders redispersible to various solvents.

Silicon nanopowder with a narrow size distribution was synthesized by a simple method, in which amorphous SiO(x) (x < 2) powder as starting material was annealed at high temperature and then etched by hydrofluoric acid (HF). Si nanoparticles thus obtained exhibited emission in the ultraviolet and visible regions under excitation at an energy corresponding to the direct band-gap transition. At the same time, they could be redispersed in various organic solvents such as octanol, toluene, etc.