Radiation-induced emission from golden hamster embryo cells

Emission from high-energy-electron-irradiated golden hamster embryo (GHE) cells has been studied over the temperature range 12–300 K both by a one-shot-single-photon-counting method and by photocurrent measurements with an oscilloscope. Emission from the irradiated phosphate buffered saline (PBS) also has been studied. The emission spectra from PBS at 12 and 77 K show a maximum around 330 and 380 nm, respectively, which are the same spectra as those from irradiated pure H₂O. The emission from irradiated GHE consists of the new band at 480 nm in addition to the emission from H₂O. The 480 nm emission is observed at the temperature range of 12–300 K, though the emission at 300 K is much lower than that at low temperature. The 480 nm emission is ascribed to the transition from excited organic substances in GHE cells. The intensity of 480 nm emission at 300 K increases linearly with increasing irradiation-dose in the range of 11–600 Gy.     

BDH-TTP as a Structural Isomer of BEDT-TTF,and Its Two-Dimensional Hexafluorophosphate Salt

Metallic behavior down to low temperature is shown by charge transfer salts of BDH-TTP ( 1 ), a structural isomer of bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF). In the case of (BDH-TTP)₂PF₆ this behavior is attributed to the structure, which is made up of κ-type sheets of BDH-TTP donor molecules and sheets of PF₆⁻ anions.     

3,3-Dimethoxypropylsulfonyl Group: A new versatile protecting and activating group for amine synthesis

3,3-Dimethoxypropylsulfonyl (Dimps) chloride was prepared and used as a new versatile sulfonating agent for ammonia, primary and secondary amines to afford corresponding Dimps-amides in excellent yields. The resulting N-nonsubstituted and N-monosubstituted Dimps-amides, activated amines, were alkylated satisfactorily under new Mitsunobu conditions. The Dimps group was removed by treatment in aqueous solution under acidic followed by basic conditions. Furthermore, epilachnene, the defensive droplets from the Mexican bean beetle, Epilachna varivestis, was synthesized utilizing this Dimps methodology in short steps.     

A novel technique for detecting single nucleotide polymorphisms by analyzing consumed allele-specific primers

We present a simple and rapid polymerase chain reaction (PCR)-based technique, termed consumed allele-specific primer analysis (CASPA), as a new strategy for single nucleotide polymorphism (SNP) analysis. The method involves the use of labeled allele-specific primers, differing in length, with several noncomplementary nucleotides added in the 5'-terminal region. After PCR amplification, the amounts of the remaining primers not incorporated into the PCR products are determined. Thus, nucleotide substitutions are identified by measuring the consumption of primers. In this study, the CASPA method was successfully applied to ABO genotyping. In the present method, the allele-specific primer only anneals with the target polymorphic site on the DNA, so it is not necessary to analyze the PCR products. Therefore, this method is only little affected by modification of the PCR products. The CASPA method is expected to be a useful tool for typing of SNPs.     

Incorporation of CdS Nanoparticles Formed in Reverse Micelles into Mesoporous Silica

The incorporation of CdS nanoparticles, prepared in reverse micellar systems, into thiol-modified mesoporous silica, such as FM41 (functionalized MCM-41) and FM48 (functionalized MCM-48), has been investigated. The nanoparticles were immobilized in the mesopores via the incorporation of water droplets of the reverse micelles. A particle-sieving effect for FM41 having large (L-FM41, 3.8 nm) and medium (M-FM41, 3.6 nm) pore size was observed, in that the incorporation of the CdS nanoparticles was decreased with increasing particle size and with decreasing pore size of the FM41. Chemical vapor deposition treatment employed to narrow the mesopores of the CdS-FM41 enhanced the stability of CdS nanoparticles against heat treatment. The CdS-FM41 composites demonstrated photocatalytic activity for H(2) generation from 2-propanol aqueous solution, the better photocatalytic activity being obtained with the larger pore size for CdS-L-FM41. Copyright 2001 Academic Press.     

Formal total synthesis of enigmazole A

A stereoselective formal total synthesis of enigmazole A, a marine macrolide isolated from Cinachyrella enigmatica, is described. Lewis acid mediated intramolecular allylation of an α-acetoxy ether, prepared from alcohol and carboxylic acid fragments was carried out to construct the methylene THP ring with high stereoselectivity. The late-stage macrolactonization of the corresponding seco-acid provided a known synthetic intermediate of enigmazole A.     

Complex formation of amphiphilic polymers with azo dyes and their photoviscosity behavior

The hydrophobic interaction of amphiphilic copolymers, which contain 2-hydroxyethyl methacrylate(HEMA) and 1vinyl-2-pyrrolidone (VPy), with Methyl Orange (MO) was compared with that of HEMA-acrylamide (AAm) copolymers to deduce the correlation between their complexation ability in a photochromic azo dye and the photoviscosity effect in aqueous copolymer/dye complex solution. On the basis of the dialysis data and fluorometric analysis it appeared that the complexation dependence on HEMA content in the copolymers was due to the hydrophobic interaction between the polymer and the dye. For a comparable HEMA content AAm copolymers bound less MO than VPy copolymers. It was confiied by photoviscosity measurements that the conformation of the complex composed of photochromic azo dye and HEMA copolymer changed reversibly in response to the photo- and thermal isomerization of the dye. In HEMA-AAm copolymer systems the photoviscosity effect was small compared with that of HEMA-VPy copolymer systems. From these results it was concluded that the complexation ability of polymers due to the hydrophobic interaction was an important factor in producing a large photoinduced conformational change in water.