Endoscopic Observation of Tissue by Narrowband Illumination

We propose a new illumination method for a medical endoscope: narrow band imaging (NBI), in which the spectral bandwidth of the filtered light is narrowed. To confirm how the spectral specifications of the filtered light influence a reproduced image, an experiment was conducted observing the endoscopic images of the back mucosa of a human tongue. In addition, the effect of NBI on endoscopic images was investigated through preliminary clinical tests in colonoscopy and upper gastrointestinal endoscopy. It has been shown that NBI can enhance the capillary pattern and the crypt pattern on the mucosa. These patterns are useful features for diagnosing an early cancer.     

A New Method for Rotation and Brightness Invariant Pattern Recognition Based on Modified Multiple Circular Harmonic Expansions

A new method for rotation and brightness invariant pattern recognition was proposed by applying multiple circular harmonic expansions to the joint transform correlator. The amplitudes of the multiple orders of circular harmonic expansions made from a detecting image were synthetically modified to respond to the same auto-correlation peaks. These modified circular harmonic expansions were arranged in the input plane as reference patterns together with an arbitrary target pattern, and the correlation signals between them were calculated in the subtracted joint transform correlator. The fraction of the correlation-peak intensities between the target and the references were extracted as a new discrimination parameter. This new parameter performs pattern recognition under rotation and brightness invariance with good discriminability. Its high discriminability has been proved in computer simulations using the face image patterns of many individuals.     

Synthesis and properties of polydiene and polypentenamer having formyl or hydroxymethyl groups and their photosensitive derivatives

cis-1,4-Polybutadiene and polypentenamer having pendant functional groups such as formyl, aldoxime, hydroxymethyl, or cinnamoyloxymethyl groups have been prepared, and some of their properties were investigated in terms of structural effect on physical properties of these polymers. cis-1, 4-Polybutadiene and polypentenamer having a different content of formyl group were prepared by the hydroformylation reaction with rhodium catalyst under mild conditions. The pendant formyl group was reduced to a hydroxymethyl group by using various reducing agents such as sodium borohydride or sodium trimethoxyborohydride which were effective to avoid a crosslinking reaction among the formyl groups. Glass transition temperature of polypentenamer having hydroxymethyl groups increased with increasing the content of the hydroxymethyl groups in the polymer. Cinnamoyl group was introduced into the polypentenamer having hydroxymethyl groups by reacting with cinnamoyl chloride so as to prepare a photosensitive rubber. The relationships between the photosensitivity of the cinnamoylated polypentenamer and the mobility of polymer main chains have been elucidated. A linear relationship between the photodimerization rate constant and the difference between ultraviolet (UV) irradiation temperature and the glass transition temperature of the polymer was found. It has become apparent that the photosensitivity of cinnamoylated polypentenamer can be estimated by the glass transition temperature of the original polymer, UV irradiation temperature, activation energy of the dimerization, and γ, which is a coefficient of the relationship between the photosensitive group concentration and the glass transition temperature of the polymer.     

Perfect crystals andq-deformed Fock spaces

In [S], [KMS] the semi-infinite wedge construction of level 1U _q (A _n ⁽¹⁾ ) Fock spaces and their decomposition into the tensor product of an irreducibleU _q (A _n ⁽¹⁾ )-module and a bosonic Fock space were given. Here a general scheme for the wedge construction ofq-deformed Fock spaces using the theory of perfect crystals is presented.LetU _q (g) be a quantum affine algebra. LetV be a finite-dimensionalU _q (g)-module with a perfect crystal base of levell. LetV _aff V [z,z ^–1] be the affinization ofV, with crystal base (L _aff,B _aff). The wedge spaceV _aff V _aff is defined as the quotient ofV _aff V _aff by the subspace generated by the action ofU _q (g) [z ^a z ^b +z ^b z ^a ]_a,b onv v (v an extremal vector). The wedge space ^r V _aff (r ) is defined similarly. Normally ordered wedges are defined by using the energy functionH :B _aff B _aff . Under certain assumptions, it is proved that normally ordered wedges form a base of ^r V _aff.Aq-deformed Fock space is defined as the inductive limit of ^r V _aff asr , taken along the semi-infinite wedge associated to a ground state sequence. It is proved that normally ordered wedges form a base of the Fock space and that the Fock space has the structure of an integrableU _q (g)-module. An action of the bosons, which commute with theU _q (g)-action, is given on the Fock space. It induces the decomposition of theq-deformed Fock space into the tensor product of an irreducibleU _q (g)-module and a bosonic Fock space.As examples, Fock spaces for typesA _2n ⁽²⁾ ,B _n ⁽¹⁾ ,A _2n ^–1/(2) ,D _n ⁽¹⁾ andD _n ^+1/(2) at level 1 andA ₁ ⁽¹⁾ at levelk are constructed. The commutation relations of the bosons in each of these cases are calculated, using two point functions of vertex operators.     

Polymerization of methyl methacrylate under ultrasonic irradiation. Part IV. Effect of ultrasonic irradiation on Grignard catalyst and stereoregularity of the polymers produced in dioxane–tetrahydrofuran mixed solvent

Two series of polymerization of methyl methacrylate with Grignard reagent in dioxane—tetrahydrofuran mixed solvent was carried out under ultrasonic irradiation. In series A, catalyst was added to the mixture of monomer and solvent, and in series B, catalyst was previously mixed with solvent. The effect of ultrasonic irradiation on Grignard catalyst and the microstructure in reacting sites were discussed on the basis of the stereoregularity of the polymers produced. The stereoregularity of the polymers in series A was higher than that in series B. The effect of ultrasonic irradiation on the stereoregularity was completely reversed in series A and B and it increased in the former and decreased in the latter. It was, therefore, assumed that ultrasonic irradiation affected the microstructure in the reacting sites in series A, while it increased the relative amount of R₂Mg which gave polymers with poor stereoregularity in series B.     

The cosmological term and a modified Brans-Dicke cosmology

Adding the cosmological term , which is assumed to be variable in this paper, to the Brans-Dicke Lagrangian, we try to understand the meaning of the term and to relate it to the mass of the universe. We also touch upon the Dirac large-number hypothesis, applying the results obtained from the application of our theory to a uniform cosmological model.     

Reactivity ratios for copolymerization of vinyl chloride with 2-methylpentyl vinyl brassylate by computerized linearization

A computerized version of the Fineman-Ross linearization procedure was used to determine reactivity ratios for copolymerization of vinyl chloride (monomer 1) and 2-methylpentyl vinyl brassylate (monomer 2). From differential refractometry data for the products of low-conversion copolymerization, the procedure gave r₁ = 1.06 and r₂ = 0.234. The ratios computed from chlorine contents of the same products were r₁ = 1.10 and r₂ = 0.239. The polarity factor (e₂) and general monomer reactivity (Q₂) calculated for monomer 2 from these ratios were, respectively, ?0.95 to ?0.98 and 0.032–0.033. The interquartile range for the copolymerization of a mixture of 60% monomer 1 and 40% monomer 2 was 1.4%. These values suggest that from suitable proportions of reactants, sufficiently homogeneous distribution of monomers can be achieved in copolymers of vinyl chloride and 2-methylpentyl vinyl brassylate to offer the possibility of effective internal plasticization.     

Synthesis of New Polyphosphazenes. The Reactions of Poly(dichlorophosphazene) with Aminotetraalkoxycyclotriphosphazene and Sodium Phenoxide

Abstract

A new poly(organophosphazenes) copolymer was formed from the reaction of aminopentafluoroethoxycyclotriphosphazene, sodium phenoxide, and poly(dichlorophosphazene). The polymer was thermoplastic and the T_g increased with an increasing amount of the phenol group. The T_g of the polymer with aminopentafluoroethoxycyclotriphosphazene attached as a pendant group was similar to the T_g of polyfluoroethoxyphosphazene.