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排序方式: 共有2047条查询结果,搜索用时 15 毫秒
1.
Yuki Shintani Taku Ohtomi Dr. Aya Shibata Dr. Yoshiaki Kitamura Koichiro M. Hirosawa Prof. Kenichi G. N. Suzuki Prof. Masato Ikeda 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(8):e202104421
Aqueous self-assembly of short peptides has attracted growing attention for the construction of supramolecular materials for various bioapplications. Herein, we describe how the thermolysin-assisted biocatalytic construction of a dipeptide hydrazide from an N-protected amino acid and an amino acid hydrazide leads to the formation of thermally stable supramolecular hydrogels. In addition, we demonstrate the post-assembly modification of the supramolecular architectures constructed in situ tethering hydrazide groups as a chemical handle by means of fluorescence imaging. 相似文献
2.
H. Akimune T. Yamagata S. Nakayama M. Fujiwara K. Fushimi K. Hara K. Y. Hara K. Ichihara K. Kawase K. Matsui K. Nakanishi A. Shiokawa M. Tanaka H. Utsunomiya M. Yosoi 《Physics of Atomic Nuclei》2004,67(9):1721-1725
Trinucleon molecular structures in 6He and 6Be were investigated by using the 6Li(7Li, 7Be)6He reaction at 455 MeV and 6Li(3He, t)6Be reaction at 450 MeV, respectively. Binary decays into t + t from a broad state at E x =18.0±1.0 MeV in 6He and into 3He + 3He from one at E x =18.0±1.2 MeV in 6Be, respectively, were observed by measuring trinucleon cluster decays in coincidence with reaction particles. The branching ratios for binary decay were estimated to be about 0.7 for 6He and 6Be. These large branching ratios show that a trinucleon cluster state exists as an isobaric partner around E x =18 MeV in 6He and 6Be. 相似文献
3.
Yozo Miura Hiroyuki Dote Hiroyuki Kubonishi Kenichi Fukuda Tomoko Saka 《Journal of polymer science. Part A, Polymer chemistry》2007,45(6):1159-1169
A dendritic macroinitiator having 16 TEMPO‐based alkoxyamines, Star‐16 , was prepared by the reaction of a dendritic macroinitiator having eight TEMPO‐based alkoxyamines, [G‐3]‐OH , with 4,4′‐bis(chlorocarbonyl)biphenyl. The nitroxide‐mediated radical polymerization (NMRP) of styrene (St) from Star‐16 gave 16‐arm star polymers with PDI of 1.19–1.47, and NMPR of 4‐vinylpyridine from the 16‐arm star polymer gave 16‐arm star diblock copolymers with PDI of 1.30–1.43. The ring‐opening polymerization of ε‐caprolactone from [G‐3]‐OH and the subsequent NMRP of St gave AB8 9‐miktoarm star copolymers with PDI of 1.30–1.38. The benzyl ether linkages of the 16‐arm star polymers and the AB8 9‐miktoarm star copolymers were cleaved by treating with Me3SiI, and the resultant poly(St) arms were investigated by size exclusion chromatography (SEC). The SEC results showed PDIs of 1.23–1.28 and 1.18–1.22 for the star polymers and miktoarm stars copolymers, respectively, showing that they have well‐controlled poly(St) arms. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1159–1169, 2007. 相似文献
4.
Heat transfer in a resist-coated silicon wafer using a bake process is theoretically evaluated by modeling the three-dimensional diffusion process, focusing on the controllability of the lithographic performance of chemically amplified resists. Six models of various ambient conditions are used. The proximity gap between the hotplate and the wafer is found to have a dominant influence on the heat transfer process for the whole system. Because the atmosphere near the wafer acts as a thermal diffusion buffer layer, no temperature gradient occurs in the resist, even when it is subjected to convective heat transfer from the resist surface. Experimental results obtained by X-ray lithography confirm the calculation results. 相似文献
5.
T. Nakayama T. Tanaka Y. Tsumoto H. Katayama M. Katto 《Applied Physics A: Materials Science & Processing》2004,79(4-6):833-836
A new method for high-quality hydroxyapatite (HAp) coating is developed, the laser-assisted laser ablation method. In this method, two lasers are used. One is used for ablation of a HAp target. The other, the assist laser, is used to irradiate a Ti substrate surface. The effects of the assist laser irradiation are to anneal the HAp coating and to improve its adhesive strength to the Ti substrate. The quality of the HAp coating depends on the delay time of the assist-laser irradiation. HAp coatings obtained at a delay time of 10 microseconds or more are more amorphous. It was confirmed that the amorphous part of a coating dissolves in simulated body fluid, while the crystalline part does not. The value of the Ca/P ratio in a coating obtained at a delay time of a few microseconds is close to the stoichiometric value. PACS 81.16.Mk 相似文献
6.
T Kai T Isami K Kobata Y Kurosaki T Nakayama T Kimura 《Chemical & pharmaceutical bulletin》1992,40(9):2498-2504
The maximum fluxes (Jmax) of beta-blockers through keratinized membranes were determined in vitro and compared with their physiochemical parameters such as lipophilicity (log k'0) and melting point (mp). Rat abdominal skin and hamster cheek pouch mucosa were used as the model membranes. Propranolol, metoprolol, timolol, pindolol, nadolol and agenolol were used as beta-blockers with a variety of physicochemical characters. Linear relations of Jmax with either log k'0 or mp were observed both in intact rat skin and in intact hamster cheek pouch, suggesting that the lipophilicity and thermodynamic activity of a drug in the crystal state primarily affect the drug's permeation through these membranes. However, the slope, dJmax/d(log k'0), for cheek pouch mucosa was greater than that for rat skin, corresponding to the lack of appendigeal shunt pathways in cheek pouch. Penetration studies using the delipidized membranes and the isolated stratum corneum sheet of hamster cheek pouch mucosa clarified that the primary rate-limiting barrier function might exist in the lipid layer of the stratum corneum. Jmax values for the tape-stripped and delipidized skins correlated with both the solubilities of drugs in the vehicle and with the mp, suggesting the polar porous characteristics of both model membranes. However, a theoretical approach confirmed that the contribution of an intracellular or aqueous pore route in the intact membrane to the permeation of drugs with positive lipophilic indexes is negligible. 相似文献
7.
Ryohei Hanayama Kenichi Hibino Shin’ichi Warisawa Mamoru Mitsuishi 《Optical Review》2004,11(5):337-343
Wavelength scanned interferometry allows the simultaneous measurement of top surface shape and optical thickness variation of a transparent object consisting of several parallel surfaces. Interference signals from these surfaces can be separated in frequency space, and their phases are detected by discrete Fourier analysis. However, these signal frequencies are shifted from the detection frequency by the refractive index dispersion of the object and a nonlinearity of the wavelength scanning. The Fourier analysis is sensitive to the detuning of the signal frequency and suffers from the multiple-beam interference noise. Conventional error-compensating algorithms cannot be applied to an object consisting of more than three reflecting surfaces. We derive a new 2N-1 sample error-compensating algorithm, which allows the phase detection of any order of harmonic frequency among the interference signals. The new algorithm suppresses the effect of signal frequency detuning as well as the multiple-beam interference noise and can be applied to the measurement of complex objects consisting of more than three reflecting surfaces. 相似文献
8.
Huricha Baigude Kaname Katsuraya Kohsaku Okuyama Kenichi Hatanaka Emi Ikeda Naokazu Shibata Toshiyuki Uryu 《Journal of polymer science. Part A, Polymer chemistry》2004,42(6):1400-1414
A novel sugar‐containing poly(ornithine) dendrimer is synthesized for possible antigen delivery and related applications. The dendrimer contains an ornithine dendron as interior scaffolding and oligosaccharides on the periphery, which provide an attachment site for a peptide antigen. Maltose or lactose is bound to both hemispherical and spherical poly(ornithine) dendrimer generation 3 (G3) by reductive amination between its reducing end and the peripheral amino group of the dendrimer using a borane‐pyridine complex in a buffer solution at 50 °C. The degree of substitution of sugar is changed by varying the molar ratio of sugar to dendrimer. When the surface of spherical poly(ornithine) dendrimer G3 is modified by binding β‐alanine to the 16 amino groups, highly substituted maltose‐ or lactose‐β‐alanine‐poly(ornithine) dendrimer G3 is obtained in high yield after 7 days of reaction. The structures of these sugar‐containing dendrimers are characterized by NMR and matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry analyses. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 1400–1414, 2004 相似文献
9.
Takanari Yasui Takeshi Ohtsuka Tetsu Suzuki Shigeki Okajima Kazuya Nakayama Mitsuru Tomioka Katsuhiro Kamimura Takeo Namekata Hiroaki Minamide Hiromasa Ito 《International Journal of Infrared and Millimeter Waves》2006,27(2):199-210
A new, wide-band, high-speed and high-sensitivity THz detector has been developed. The prototype detector consists of a parabolic
cylindrical mirror, a long wire antenna and a Schottky barrier diode. Direct detection measurements have shown a stable sensitivity
of 150 ± 50 V/W for 1–2 THz without any adjustments. The long wire antenna was fixed at the focus of parabolic cylindrical
mirror then it has been realized less operation steps, easy coupling to the external THz signals and a dramatic enhancement
in the practicality of this system. The optically polished mirror and frosted surface one showed comparable sensitivities,
thus easy polishing and less cost mirror fabrication can be applied for this system. The radiation pattern showed a maximum
radiation angle of approximately 23° with its dominant main lobe, which was attributed to the wire antenna character and confirmed
good agreements with classical antenna theory. 相似文献
10.
Tetsuya Okuyama Masaru Nakayama Yoshitsugu Tomokiyo Omer Van Der Biest 《Microscopy and microanalysis》2002,8(1):11-15
Lattice strains around a platelet oxygen precipitate in Si wafer is studied by energy filtering convergent-beam electron diffraction (CBED) and calculations based on the finite element method (FEM). Local lattice strains are measured from CBD patterns obtained with a probe size less than 2 nm in a specimen thicker than 450 nm. Strains measured are compressive along a direction normal to a plate of the precipitation and tensile along a direction parallel to the plate. Two-dimensional stress fields near the precipitate are obtained with FEM computer analyses by fitting the measured strains. It appears that shear stresses are concentrated at the end of the precipitate edge and the maximum shear stress at an interface between the precipitate and the Si-matrix is 1.9 GPa. It is demonstrated that a combination of the energy filtering CBED and FEM is very useful for the study of local strains near interfaces in semiconductor devices, in particular for the study of stress fields that are too steep for application of the conventional CBED technique. 相似文献