Self-assembled DNA-conjugated polymer for novel DNA chip.

We developed DNA-conjugated polymer for DNA chip fabrication. A 30 mer probe DNA and disulfide bridges were covalently attached to the polymer side chain. The DNA-conjugated polymer can be specifically adsorbed on a gold substrate surface by a self-assembly technique. The interaction between fully matched DNA and DNA-conjugated polymer was investigated by surface plasmon resonance (SPR) technique. The DNA-conjugated polymer-modified gold surface highly recognized fully matched DNA, rather than unmatched DNA. Therefore, DNA-conjugated polymer can be used for novel DNA chip fabrication.     

Alternating copolymerization of carbon dioxide and epoxide by manganese porphyrin: The first example of polycarbonate synthesis from 1-atm carbon dioxide

The first successful example of the formation of polycarbonate from 1-atm carbon dioxide and epoxide was demonstrated by the alternating copolymerization of carbon dioxide and epoxide with manganese porphyrin as a catalyst. The copolymerization of carbon dioxide and cyclohexene oxide with (porphinato)manganese acetate proceeded under the 1-atm pressure of carbon dioxide to give a copolymer with an alternating sequence. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3549–3555, 2003     

A fully linear-time approximation algorithm for grammar-based compression

A linear-time approximation algorithm for the grammar-based compression is presented. This is an optimization problem to minimize the size of a context-free grammar deriving a given string. For each string of length n, the algorithm guarantees approximation ratio without suffix tree construction.     

Development of measuring magnetic Compton profiles by grazing incidence geometry

A novel technique of measuring a magnetic Compton profile using the grazing angle geometry against a sample surface (Grazing Incidence Magnetic Compton Profile) has been successively developed. Measurements of a magnetic moment and a magnetic Compton profile are possible for a Fe 200 nm film on a thick glass substrate. The estimated thinnest limit for measurements is 100 nm for a Fe film.     

P-Chirogenic phosphonium salts: preparation and use in Rh-catalyzed asymmetric hydrogenation of enamides

P-Chirogenic trialkylphosphonium salts were prepared from the corresponding free phosphines by treatment with a strong acid (HBF₄ or HOTf). No racemization of the phosphonium salts occurred in methanol or water even at considerably high temperature. The salts were conveniently used in rhodium-catalyzed asymmetric hydrogenation of enamides.     

Dihydroboronium derivatives of (S,S)-1,2-bis(t-butylmethylphosphino)ethane as convenient chiral ligand precursors

Dihydroboronium derivatives of (S,S)-1,2-bis(t-butylmethylphosphino)ethane (t-Bu-BisP*) were prepared and used as chiral diphosphine ligand precursors in Rh-catalyzed asymmetric hydrogenation of methyl (Z)-acetamidocinnamate to afford the hydrogenation product in up to 94% enantioselectivity.     

Note on induced subgraphs of the unit distance graphE n

The unit distance graphE ⁿ is the graph whose vertices are the points in Euclideann-space, and two vertices are adjacent if and only if the distance between them is 1. We prove that for anyn there is a finite bipartite graph which cannot be embedded inE ⁿ as an induced subgraph and that every finite graph with maximum degreed can be embedded inE ^N ,N=(d ³ –d)/2, as an induced subgraph.     

A construction of lattices on certain solvable Lie groups

The purpose in this paper is to prove that there exists a lattice on certain solvable Lie groups and to construct a symplectic solvmanifold with the Hard Lefschetz property, and a locally conformal Kähler solvmanifold. We see that minimal models for these solvmanifolds are formal.     

Synthesis of 5-heteroarylazulenes: first selective electrophilic substitution at the 5-position of azulene

1,3-Di-tert-butylazulene reacted with highly electrophilic trifluoromethanesulfonate of N-containing heterocycles to give 5-(dihydroheteroaryl)azulene derivatives in good yield and treatment of the 5-(dihydroheteroaryl)azulene derivatives with KOH afforded 5-(heteroaryl)azulenes in excellent yield.