Preparation of palladium film by coating photolysis process using KrF or ArF excimer laser

The preparation of palladium (Pd) films has been investigated using KrF or ArF laser irradiation on a Pd acetate (PdAc) coated substrate. A crystalline Pd film could be obtained by KrF laser irradiation (fluence = 15-40 mJ/cm²) but PdAc was found to remain in the film. An increase in the substrate temperature to 423 K decreased the inclusion of the unreacted precursor and produced a better crystallinity. An amorphous and uniform Pd film composed of very fine particles was found to be formed by this process under reduced pressure, which is probably due to the preferential ablation of the crystalline nuclei. ArF laser irradiation is more effective for decomposing the PdAc and for producing a Pd film with a better crystallinity and no (or smaller) organic inclusion.     

Gonyol: Methionine-induced sulfonium accumulation in a dinoflagellate Gonyaulax polyedra

Gonyol, 3S-5-dimethylsulfonio-3-hydroxylpentanoate, was isolated from a dinoflagellate Gonyaulax polyedra cultured in a medium containing methionine and the structure was elucidated by spectroscopic method and confirmed by chemical synthesis. Gonyol was shown to be biogenetically derived from methionine and acetic acid.     

Determination of cysteine concentration by fluorescence increase: reaction of cysteine with a fluorogenic aldehyde

A fluorogenic method for the determination of cysteine concentration has been developed.     

Development of Fiber Optic Sensing System for Analyzing Isozymes Reaction of Cytochrome P450-1A Doubted as Carcinogen Activator

This paper presents a high performance fiber-optic sensing system for analyzing the isozymes reaction of cytochrome P450 (CYP). In the inherent biological system of lifeguard against chemical toxicants, the enzymes metabolize such chemical species to safer formulae. As is well known, some particular types of CYP, such as CYP-1A, however, often trigger the cancer development process by selective activation of carcinogen. A new technique for medical diagnosis of cancer development at very early or even predictive stage may be achievable based on the evaluation of the activity of the enzymes related to the cancer development by using the present system. In order to demonstrate the potential of the system, CYP-1A induced in liver of living rats by medication using 2,3,7,8-tetrachloro-dibenzofuran (2,3,7,8-TCDF) is measured and curves revealing the fluorescent power transition for each concentration of toxicants are successfully observed with good sensitivity.     

Stereospecific cycloaddition of heterocumulenes to oxiranes catalyzed by organotin halide complexes

Stereospecific cycloaddition of 2,3-disubstituted oxiranes to heterocumulenes, including carbodiimides, isocyanates and carbon dioxide, is catalytically promoted by dialkyltin diiodide-hexamethylphosphoric triamide (HMPA) system, producing various five-membered heterocycles, where the configuration of the carbons in the oxirane ring is retained. In particular, the addition of isocyanates to oxiranes gave stereo-specifically two types of products, dioxolan-2-imines and oxazolidin-2-ones independently, while the rearrangement of the former to the latter product has been already proposed.