On {sigma}-Normal C*-Algebras

A C*-algebra A is said to be monotone (respectively monotone-) complete if every increasing net (respectively increasingsequence) of elements in the ordered space A_h of all hermitianelements of A has a supremum in A_h. It is straightforward toverify that every monotone complete C*-algebra is an AW*-algebra.For type I AW*-algebras, the converse is known to be true. However,for general AW*-algebras, this question is still open, althoughan impressive attack on the problem was made by E. Christensenand G. K. Pedersen, who showed that properly infinite AW*-algebrasare monotone -complete [4]. 1991 Mathematics Subject Classification46L05, 46L06.     

Upper bounds for the number of facets of a simplicial complex

Here we study the maximal dimension of the annihilator ideals
of artinian graded rings with a given Hilbert function, where is the polynomial ring in the variables over a field with each , is a graded ideal of , and is the graded maximal ideal of . As an application to combinatorics, we introduce the notion of -facets and obtain some informations on the number of -facets of simplicial complexes with a given -vector.

     

Local conformation of poly(1-adamantyl methacrylate) evaluated from intrinsic viscosity

The dilute-solution properties of poly(1-adamantyl methacrylate), which was prepared by radical polymerization in benzene at 60 °C and fractionated with benzene and ethanol as solvent and nonsolvent, respectively, were examined by the measurement of intrinsic viscosities in benzene, tetrahydrofuran, and cyclohexanone at 30°C. The Mark-Houwink-Sakurada equations were established for each solvent-polymer system. From the viscosity data in these three solvents by means of the Burchard-Stockmayer-Fixman plot, the characteristic ratio and steric factor of the chain were determined to be 16.7 and 2.9, respectively, which are higher than the values reported for other methacrylate polymers bearing cycloalkyl esters.     

Triplet state formation of aromatic hydrocarbons quenched with silver ion in ethanol

Fluorescence quenching rate constants of aromatic hydrocarbons by silver ions are determined. The values obtained are not well interpreted with thermodynamical considerations based on an electron transfer mechanism, but related to the intersystem crossing rate constant of the fluorescer. Triplet state formation in the course of quenching has been confirmed by laser photolysis studies.     

The first A2B2-heterometal ferrimagnetic chain. Structures and magnetic properties of polymeric [Gd2Cu2]n and the corresponding monomer

One-dimensional polymeric complexes consisting of alternating dicopper(II) and digadolinium(III) units exhibited ferrimagnetic behavior which was ascribable to antiferromagnetic coupling across the oximate N-O bridges between the high-spin homodinuclear units.     

Effect of UV-absorbing agents on photodegradation of tranilast in oily gels

Tranilast (TL) oily gels containing UV-absorbing agents (UV absorber) were prepared, and the effect of the agents against photodegradation of TL was investigated. When 0.1% TL oily gel without UV absorber was exposed to light, TL was photochemically decomposed to the extent of 74.1% of its initial content at the end of the first hour. Although there were differences in the preventive effect on photodegradation of TL depending on the UV absorbers employed, 2-(2-benzotriazolyl)-p-cresol (BTPC) was the most effective absorber. The addition of UV absorbers to the oily gel did not affect the release of TL from the gel, the skin permeation, or the skin concentration of TL following topical application. UV absorbers added to TL oily gel penetrated into skin; however, their concentration in skin was similar to that following application of commercial sunscreen. These results suggest that the addition of UV absorbers to the oily gel of TL may be useful in preventing photodegradation of TL in the gel.     

Synthetic approaches toward ecteinascidins. Part 2. Preparation of the ABCDE ring system of ecteinascidins having characteristic substituents in both benzene rings

A synthesis of an advanced ABCDE ring system (24c) having characteristic substituents in both benzene rings of ecteinascidin marine natural products is described based on our model studies.     

Intramolecular [3+2] cycloaddition reaction of α,β-enoate derivatives having allylsilane parts: 1,1′-biphenyl-2,2′-di(triflyl)amide (BIPAM)+2Me2AlCl as a novel Lewis acid

The bidentate Lewis acid generated by mixing 1,1′-biphenyl-2,2′-di(triflyl)amide (BIPAM) and 2 M equiv of Me₂AlCl can efficiently promote the intramolecular [3+2] cycloaddition reaction of α,β-enoate derivatives having ester tether linking α,β-unsaturated ester and allylsilane parts.