Stratum Corneum Structure of Psoriasis Vulgaris Investigated by EPR Spin-Probe Method

Electron paramagnetic resonance (EPR) spin-probe method was used to investigate structural aspects of psoriasis vulgaris SC (pv-SC). EPR spectra of the SC samples were analyzed using order parameter (S ₀) and rotational diffusion rates. A little, broad three-line pattern of 5-doxylstearic acid (spin probe) in pv-SC was observed. The spectral pattern of pv-SC is quite different from those of control SC reported. The S ₀ values obtained for the pv-SC and the control were approximately 0.20 and 0.49, respectively. The statistical analysis suggests that the 0.20 value of pv-SC is significantly smaller than the 0.49 value of the control (p < 0.01). The rotational diffusion rates for the probe motion in the SC were faster than those of the control. Moreover, there was no spectral difference of the glass plate with the SC against the static magnetic field, except for the signal intensity. Therefore, the pv-SC is less rigid of the structure than that of the control SC, indicating irregular architecture of pv-SC. The present results suggest that the EPR assay is of great use for evaluating various SC function and can be extended to other skin diseases with abnormal keratinization.     

New triterpenoid saponins from leaves of Panax japonicus (3). Saponins of the specimens collected in Miyazaki prefecture

Two new dammarane-type triterpenoid saponins, chikusetsusaponin LM1 (1), chikusetsusaponin LM2 (2), and three known triterpenoid saponins, ginsenoside Re (3), ginsenoside Rg1 (4), ginsenoside F3 (5), were isolated from the leaves of P. japonicus C. A. Meyer collected in Miyazaki prefecture, Japan. The structures of new chikusetsusaponins were elucidated on the basis of spectroscopic and physicochemical evidences.     

Experimental evidence and theoretical analysis for the chiral symmetry breaking in the growth front of conglomerate crystal phase of 1,1'-binaphthyl

Chirally asymmetric states, chemical oscillations, propagating chemical waves, and spatial patterns, are examples of far-from-equilibrium self-organization. We have found that the crystal growth front of 1,1(')-binaphthyl shows many of the characteristics of an open system in which chiral symmetry breaking has occurred. From its supercooled molten phase, 1,1(')-binaphthyl crystallizes as a conglomerate of R and S crystals when the temperature is above 145 degrees C. In addition, 1,1(')-binaphthyl in its molten phase is always racemic due to its high racemization rate. Under appropriate conditions, bimodal probability distribution of enantiomeric excess (ee) with maxima around 60% was observed. The ee was mass independent, indicating that the growth front maintains a constant ee. A kinetic model that theoretically analyzes the chiral symmetry breaking transition in the growth front of a conglomerate crystal phase was formulated. Computer simulation of the model reproduced not only the average but also the large variation of the ee observed in crystallization experiments.     

Intelligent feedback release systems and the application to neuron network model research

Intelligent feedback release systems, consisting of radiation-prepared porous polycarbonate film or silicone chip and radiation crosslinked stimuli-sensitive hydrogels with immobilized enzymes as a sensor–actuator gate were constructed. Those systems showed various signal responsive substance release functions, and selective signal transfer functions. The application of those integrated intelligent systems as neural network model was investigated.     

Stretching of slow positron pulses generated with an electron linac

A facility for generating a high intensity slow positron beam using an electron linear accelerator has been constructed. A conversion efficiency of 6×10^–7 slow positrons per incident electron has been obtained for 75 MeV electrons. Storage and stretching of pulsed slow positrons have been successfully carried out with a Penning trap.     

Extended fine structure in characteristic X-ray fluorescence: A novel structural analysis method of condensed systems

An oscillation similar to that in extended X-ray absorption fine structure (EXAFS) is found in characteristic X-ray fluorescence spectra, originating from a quantum interference effect during the X-ray emission process in a solid. We observe the oscillating fine structure in the radiative Auger X-ray fluorescence spectra of aluminum metal. The Al-Al interatomic distances are successfully reproduced by the Fourier transform of the fine structure. Thus, the present method has the potential to become a convenient alternative to EXAFS measurement for light elements.     

Colorimetric detection of fluoride ion in an aqueous solution using a thioglucose-capped gold nanoparticle

The thioglucose-capped gold nanoparticles have been prepared by the chemical reduction of HAuCl₄ using thioglucose as the reducing and capping agent, which displays selective colorimetric detection of fluoride ion in 10 mM HEPES buffer at physiological pH.     

Determination of the As(III)/As(V) ratio in soil by X-ray absorption near-edge structure (XANES) and its application to the arsenic distribution between soil and water.

The details of a method used to determine the As(III)/As(V) ratio in soil by arsenic K-edge XANES spectroscopy are described. The spectra of mixtures of NaAs(III)O2 and NaH2As(V)O4, conducted for an As(III)/As(V) calibration, were well-fitted by combining normalized spectra of NaAsO2 and Na2HAsO4, where the coefficients multiplied by the normalized spectra were identical to the molar ratio of As(III) and As(V) in the mixtures. XANES spectra of arsenic in soil samples could also be fitted by a linear combination of the spectra of NaAsO2 and Na2HAsO4, which enabled us to estimate the As(III)/As(V) in a soil containing 10.2 mg/kg arsenic. The As(III)/As(V) ratio in the soil was compared with that of a soil solution contacted with the soil determined by HPLC-ICP-MS, showing that As(III) is distributed to water more readily than As(V). The application of the XANES method is important for a better understanding of the behavior of As(III) and As(V) independently in a natural aquifer.     

Catalytic cyclopropanation of alkenes via (2-furyl)carbene complexes from 1-benzoyl-cis-1-buten-3-yne with transition metal compounds

The reaction of alkenes with conjugated ene-yne-ketones, such as 1-benzoyl-2-ethynylcycloalkenes, with a catalytic amount of Cr(CO)(5)(THF) gave 5-phenyl-2-furylcyclopropane derivatives in good yields. The key intermediate of this cyclopropanation is a (2-furyl)carbene complex generated by a nucleophilic attack of carbonyl oxygen to an internal alkyne carbon in pi-alkyne complex or sigma-vinyl cationic complex. A wide range of late transition metal compounds, such as [RuCl(2)(CO)(3)](2), [RhCl(cod)](2), [Rh(OAc)(2)](2), PdCl(2), and PtCl(2), also catalyzes the cyclopropanation of alkenes with ene-yne-ketones effectively. When the reactions were carried out with dienes as a carbene acceptor, the more substituted or more electron-rich alkene moiety was selectively cyclopropanated with the (2-furyl)carbenoid intermediate.