Xia Spectrum for Some Class of Operators

In this paper, we introduce Xia spectra of n-tuples of operators satisfying |T ²| ≥ U|T ²|U* for the polar decomposition of T = U|T| and we extend Putnam’s inequality to these tuples [7]. This research is partially supported by Grant-in-Aid Research No.17540176.     

Isolation and structure of four new ceramides from the starfish Luidia maculata

A new sphingosine-type ceramide LMCer-1-1 (1) and three new phytosphingosine-type ceramides, LMCer-2-1 (2), LMCer-2-6 (3), and LMCer-2-7 (4), were isolated from the anti-hyperglycemic active ceramide molecular species LMCer-1 and LMCer-2, obtained from the less polar fraction of the chloroform-methanol extract of the whole bodies of Luidia maculata. The structures of these ceramides were determined on the basis of chemical and spectroscopic evidence as: (2S,3R,4E,2'R)-2-(2-hydroxyhexadecanoylamino)-16-methyl-4-octadecene-1,3-diol (1), (2S,3S,4R,2'R)-2-(2-hydroxyhexadecanoylamino)-16-methyl-octadecane-1,3,4-triol (2), (2S,3S,4R,2'R)-2-(2-hydroxydocosanoylamino)-hexadecane-1,3,4-triol (3), and (2S,3S,4R,2'R)-2-(2-hydroxydocosanoylamino)-14-methyl-hexadecane-1,3,4-triol (4).     

Synthesis and optical properties of new conjugated polymers composed of 1,3,4‐thiadiazole and 2,5‐dialkoxybenzene rings

Intramolecular cyclization of precursor polyhydrazides derived from hydrazine and four 2,5‐dialkoxyterephthalic acids by direct polycondensation with Lawesson's reagent afforded new conjugated polymers constituted of 1,3,4‐thiadiazole and 2,5‐dialkoxybenzene units. The polymers emitted bluish green light in solution and green light in solid state in spite of the coexistence of non‐cyclized hydrazide linkage in the backbones, the Stokes shifts being 91–138 nm in the solid state. It was suggested that these polymers have appropriate lengths of conjugation backbones based on the 1,3,4‐thiadiazole moiety.