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Yutaka Nagata

Publications and source records attributed to Yutaka Nagata.

5 recordsLinked to original sources
PubMed2006

Nanophase-separated synchronizing structure with parallel double periodicity from an undecablock terpolymer.

A new nanophase-separated structure with parallel double periodicity has been identified for an undecablock terpolymer in bulk. The polymer includes two long poly(2-vinypyridine) (P) chains on each end, with five short polyisoprene (I) and four short polystyrene (S) chains at the center. This polymer exhibits a hierarchical lamellar structure with two crystallographic periods: 88 nm and 16 nm. The 88 nm period includes one thick P lamella and five thin I-S-I-S-I lamellae, of extremely high orientation.

Butadienes↗
PubMed2006

Development of high-throughput, high-damage-threshold beam separator for 13 nm high-order harmonics.

We demonstrate a high-throughput, high-damage-threshold beam separator for wavelengths shorter than 30 nm, which uses a 10 nm thick niobium nitrogen film prepared on a Si substrate, set at the Brewster angle relative to the pump wavelength. The film was deposited by rf reactive magnetron sputtering on a Si substrate. The beam separator has an attenuation ratio of 0.01 and a damage-threshold intensity of at least 0.8 TW/cm2 for a 26 fs pump pulse. The measured reflectivity of the beam separator exceeded 70% in a wavelength range of 13-18 nm. This broadband beam separator may be used to eliminate energetic laser pulses from longitudinally pumped x ray lasers as well as from high-order harmonics.

Journal Article↗
PubMed2006

Diblock-type supramacromolecule via biocomplementary hydrogen bonding.

Control of nanostructure formation by a diblock-type supramacromolecule via biocomplementary hydrogen bonding has been achieved. Two different homopolymers, poly(4-trimethylsilylstyrene) and poly(styrene-d8), that are end-decorated with complementary oligonucleotides, i.e., thymidine phosphates and deoxyadenosine phosphates, were prepared by using the phosphoramidite method and blended successively. Association behavior in a blend solution was examined with NMR, and a cast bulk film obtained from the solution has been confirmed to show a nanophase-separated structure by transmission electron microscopy and X-ray scattering. Suppression of this nanostructure formation of a block-type supramacromolecule was also attained by adding a smaller agent as an inhibitor.

Deoxyadenine Nucleotides↗
PubMedDate not supplied

Novel synthesis and characterization of bioconjugate block copolymers having oligonucleotides.

Novel and efficient synthesis of polymers terminated with nucleotides via the phosphoramidite method has been developed. A hydroxyl-terminated polymer was converted into a polymer capped with a nucleotide in three steps, where the conversion of the reactions was very high, almost 100%. By repetition of this synthetic method, a block copolymer composed of a synthetic polymer, polystyrene, and biological oligonucleotides with thymidine units has been successfully synthesized. A microphase-separated structure of this block copolymer was observed by both transmission electron microscopy and small-angle X-ray scattering, and a cylindrical structure was confirmed.

Biopolymers↗