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21.
Toshifumi Yui Kiego Miyawaki Yoshinobu Kawano Kozo Ogawa 《Journal of carbohydrate chemistry》2013,32(8):905-914
ABSTRACT Miniature crystal models of six small carbohydrates were examined using the PM3 semiempirical quantum mechanics method. The minicrystal structures, consisting of 27 sugar residues, were optimized by the combined procedure of partial optimization and reconstruction of the model, while maintaining the original crystal symmetries. All of the minicrystals were successfully optimized without exhibiting a great increase in an energy at any reconstruction step. Some minicrystals showed a prolonged behavior of optimization cycles. A major source of structure change appeared to arise from hydroxyl group rotations wherein the largest movements mostly occurred in an early optimization stage. No significant deformations in geometry of either residues or hydrogen bonds were observed in the final minicrystal structures. The thermodynamic values calculated for the optimized minicrystals were in reasonably good agreement with the literature data. The present study indicated that the PM3 semiempirical method successfully predicted the basic features of intermolecular hydrogen bonding involved in a condensed system. 相似文献
22.
Supramolecular Polyelectrolyte Complexes of Bone Morphogenetic Protein‐2 with Sulfonated Polyrotaxanes to Induce Enhanced Osteogenic Differentiation 下载免费PDF全文
23.
Bin Dong Di Qin Hong L. Shi Yui R. Fang Wen Z. Wang Yang Y. He Bao S. Cao Yan X. Liu Yong Ding 《Mikrochimica acta》2014,181(7-8):791-795
We report on the synthesis and optical spectra of silver nanorice particles. Two strong absorption bands are resolved in the near UV and near-IR region, and the dark field scattering spectra are consistent with the absorption spectra. Finite-difference time-domain simulations reveal that the peak in the IR region can be attributed to the E field that is parallel to the long axis, while the peak in the UV can be attributed to the E field perpendicular to the short axis of the silver nanorice particles. Figure
This paper reports on the synthesis of Ag nanorices, and their characterization by optical absorption, TEM, dark field scattering microscopy of single Ag nanorice and theoretical simulations using time domain finite-difference time-domain method. Electric field distribution of Ag nanorice dimer excited by polarization along long axis. 相似文献
24.
1,2,3-Benzotriazin-4(3H)-ones and 1,2,3,4-benzothiatriazine 1,1(2H)-dioxide reacted with isocyanides in the presence of a palladium catalyst to give 3-(imino)isoindolin-1-ones and 3-(imino)thiaisoindoline 1,1-dioxides, respectively, in high yield. An intermediate azapalladacycle was generated through denitrogenation of the triazine moiety, and an isocyanide was incorporated therein. 相似文献
25.
We synthesized new porous coordination polymers (PCPs) {Ln(III)[Co(III)(dcbpy)(3)]·nH(2)O} (Ln = La(3+), Nd(3+), Gd(3+); H(2)dcbpy = 4,4'-dicarboxy-2,2'-bipyridine) and characterized them by X-ray diffraction and vapor-adsorption measurements. These three Ln-Co-based PCPs have similar rock-salt types and highly symmetrical porous structure and show a reversible structural collapse-regeneration accompanied by water-vapor desorption-adsorption. Similar structural regeneration was also observed for the Gd-Co PCP upon exposure to MeOH and CH(3)CN vapors, whereas the remaining two PCPs barely responded to organic vapors. 相似文献
26.
We give a parametric family of quintic polynomials of the form x5 + ax + b (a, b ∈ ) with dihedral Galois group D5. Some properties of the fields defined by these polynomials are also described. 相似文献
27.
Itoh T Shichi T Yui T Takagi K 《Langmuir : the ACS journal of surfaces and colloids》2005,21(8):3217-3220
The present investigation reports on the significant differences observed in the efficiency of the polymerization depending on the odd- or even-numbered methylene chains of diacetylenecarboxylates, CH3(CH2)(m-1)C[triple bond]C-C[triple bond]C(CH2)(n-1)CO2- (mono-[m,n]), incorporated in layered double hydroxide (LDH) clay. Upon gamma-ray irradiation of the diacetylenecarboxylates, or mono-[m,n], in LDH clay, polymer hybrids or poly-[m,n]/LDH, which exhibited coloring from light orange to violet, were obtained. The color of the poly-[m,n]/LDH hybrids was strongly dependent on the extent of the polymerization degrees. Moreover, the polymerization degrees were controlled by the number of methylene spacers n between the carboxyl and diacetylene groups. An odd-numbered n for the methylene chain of mono-[m,n] was found to be the determining factor in the efficient polymerization of these self-assembling aggregates within the interlayers of LDH clay. 相似文献
28.
Guo Y Yui H Minamikawa H Masuda M Kamiya S Sawada jT Ito K Shimizu T 《Langmuir : the ACS journal of surfaces and colloids》2005,21(10):4610-4614
The local hydrogen-bonding environment of water confined in glycolipid nanotubes (LNTs) was investigated by Fourier transform infrared (FT-IR) spectroscopy. Using X-ray diffraction (XRD), we estimated the thickness of an interlamellar water layer, which was confined between the bilayer membranes constructing the walls of the LNTs, to be 1.3 +/- 0.3 nm. FT-IR spectroscopic measurement of the confined water showed an obvious reduction in IR absorption in both the low-energy (around 3000 cm(-1)) and high-energy regions (around 3600 cm(-1)) of the OH stretching band as compared to bulk water. The reduction around 3000 cm(-1) indicated a decrease in the relative proportion of the water molecules with a long-range network structure due to a geometrical restriction. This agrees with the results obtained for other multilamellar systems. On the other hand, the remarkable reduction around 3600 cm(-1), which was not observed in the other systems, indicated the absence of weakly hydrogen-bonded water aggregates due to the effect of sugar headgroups. 相似文献
29.
Positivity - For a compact convex subset K of a locally convex Hausdorff space, a measurement on A(K) is a finite family of positive elements in A(K) normalized to the unit constant $$1_K , $$... 相似文献
30.
Ooya T Inoue D Choi HS Kobayashi Y Loethen S Thompson DH Ko YH Kim K Yui N 《Organic letters》2006,8(15):3159-3162
[Structure: see text] A polypseudorotaxane consisting of cucurbit[7]uril (CB[7])/N,N'-(3-phenylenebis(methylene)dipropargylamine (PMPA), [2]pseudorotaxane, and 2,6-O-dimethyl beta-cyclodextrin (DM-beta-CD)/alpha,omega-bisazidopropylene glycol 400 [2]pseudorotaxane was synthesized using the "click" reaction. The polypseudorotaxane structure was maintained in aqueous solution over a wide range of pH values with the DM-beta-CD units contributing to increased solubilization of the polypseudorotaxane without dethreading. The pH-responsive movement of the CB[7] units in the polypseudorotaxane was also observed. 相似文献