Embedding of a Banach algebra

Given a Banach space , we have shown in 1994 that a product can be defined on it in such a way that the resulting Banach algebra is isomorphic to a compact subalgebra of the algebra of all bounded linear operators on the topological dual of . Our purpose here is to prove that, more generally, any Banach algebra admitting a left approximate identity, is isomorphic to a subalgebra of , the isomorphism being isometric, provided the approximate identity is bounded by 1. As a consequence, we get a factorization through , of the elements in .

     

Facile synthesis of alpha,alpha-diisobutylglycine and anchoring its derivatives onto PAL-PEG-PS resin

alpha,alpha-Diisobutylglycine has been synthesized using a Pd-mediated dialkylation of ethyl nitroacetate as a key first step. The free alphaalphaAA is N(alpha)-protected and has been applied to the assembly of conformationally constrained peptide analogues. Mixed anhydrides from BOP-Cl and Fmoc-alphaalphaAA-OH are used for anchoring alphaalphaAAs onto a trialkoxybenzyl linker on PEG-PS grafted support, upon which a beta-strand mimic with difficult sequence is assembled in a superior quality.     

Co-tunneling of the charge through a 2-D electron island

A double barrier Single Electron Transistor is realized in two dimensions by confining the 2-D electron gas of a GaAs/GaAlAs heterojunction to a small island by means of Schottky gates. Two gates provide adjustable tunnel barriers and a central gate controls the electron number in the island. The island has small single-particle energy level spacing and forms a metallic island. Periodic conductance oscillations characteristic of Coulomb blockade are observed when the central gate voltage is varied. The ability to vary the tunnel conductance allows us to study the basic physics of the Coulomb blockade: our results show that the quantum charge fluctuation mechanism which limits the tunneling blockade at low temperature is of second order in tunnel barrier transparencies in agreement with the charge Macroscopic Quantum Tunneling (q-MQT) or co-tunneling model.     

Esters phosphoriques cycliques ou non cycliques de quelques O-isopropylidène-1,2-α-D-pentofurannoses. Communication préliminaire

Cyclic and acyclic phosphate esters of some 1,2-O-isopropylidene-α-D -pentofuranoses When treated with monophenyl phosphorodichloridate, 1,2-O-isopropylidene-α-D -xylofuranose gave the two possible, isolable isomers of the corresponding 3,5-cylic phenylphosphate. Upon phosphorylation of the same sugar derivative using bis (2,2,2-trichloroethyl) phosphorochloridate only one isomer was formed. The same situation obtained when preparing 1,2-O-isopropylidene-α-D -ribofuranose-3,5-cyclic phenylphosphate. The synthesis of a new kind of sugar phosphate with a branched-chain unsaturated sugar moiety namely the trans-3-deoxy-3-C-cyanomethylene-1,2-O-isopropylidene-D -erytho-pentofuranose 5-bis(2,2,2-trichloroethyl) phosphate is also described.     

ChemInform Abstract: Structural Study of the NaCdVO4—Cd3V2O8 and CdO—V2O5 Sections of the Ternary System Na2O—CdO—V2O5.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.     

ChemInform Abstract: Infrared Spectroscopy of Hydrated Bicarbonate Anion Clusters: HCO3‐(H2O)1‐10.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.