We introduce a notion of depth three tower of three rings C ⊆ B ⊆ A with depth two ring extension A |B recovered when B = C. If A = EndBC and B |C is a Frobenius extension, this captures the notion of depth three for a Frobenius extension in [12, 13] such that if B |C is depth three, then A |C is depth two (a phenomenon of finite depth subfactors, see [20]). We provide a similar definition of f...

The mechanism of the cycloaddition reaction between singlet state dichlorosilylene germylidene (Cl2Si=Ge:) and acetone has been investigated with B3LYP/6-31G* and B3LYP/6-31G** method, from the potential energy profile, we predict that the reaction has one dominant reaction pathway. The presented rule of the reaction is that the two reactants firstly form a Si-heterocyclic four-membered ring ge...

The present paper describes a new media access control protocol, called the multiple token protocol, for high-speed ring networks. The purpose of this protocol is to increase the throughput under a heavy load and to decrease the access delay under a light load ofthe token-ring protocol. The protocol maintains several logical token-rings in the single physical ring. The number of logical rings c...

The aminomethyl cyclopalladated complex is identified as a key intermediate for promoting the C–N bond activation of tertiary amines via reductive elimination and oxidative addition sequence. This strategy has enabled palladium-catalyzed ring-closing reaction enynols with aminals methylene transfer activation, which provides rapid access to densely functionalized O-heterocycle containing alleni...

The mechanism of protein synthesis is still unknown due to inability to detect the so-called enzyme "peptidyl transferase" even after elucidation of high-resolution crystal structure of ribosome. We have recently shown by model building and semi-empirical energy calculation that the tRNA molecule at P-site of ribosome may act as peptidyl transferase (Das et al. (1999) J. Theor. Biol. 200, 193-2...

in this note we introduce the notion of weak mccoy rings as a generalization of mccoy rings, and investigate their properties. also we show that, if is a semi-commutative ring, then is weak mccoy if and only if is weak mccoy.

Tricyclic lactam model compounds of the left half (ABC ring) of renieramycin and saframycin anticancer natural products were prepared from common intermediate 6a. Readily available alcohol 6a was converted into enamide 8, and this was followed by transformation into 6b through a hydrobromination reaction in a stereoselective manner. Some diastereomers at C-6 to C-11a of the tricyclic lactam mod...

substituted 2, 4- diphenyl quinolines were synthesized by a multicomponent domino reaction of anilines, aldehydes and terminal aryl alkynes. the synthetic pathway involves the formation of an imine, followed by the intermolecular addition of an alkyne to the imine. this intermediate immediately undergoes ring closure and oxidative aromatization. the reaction is catalyzed by natural kaolin, a st...