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991.
Mihoko Maruyama Noriko Shimizu Shigeru Sugiyama Yoshinori Takahashi Hiroaki Adachi Kazufumi Takano Satoshi Murakami Tsuyoshi Inoue Hiroyoshi Matsumura Yusuke Mori 《Journal of Crystal Growth》2010,312(19):2771-2774
Silicone glue (modified silicone polymer) is widely used for both experiments involving inorganic crystal growth and those involving organic materials like proteins. This material is very useful for building a hand-made experiment setup or for fixing protein crystals to specific locations. Though silicone glue is regarded as harmful to proteins, no systematic verification was performed to investigate its impurity effects on protein crystal growth. We focused on and estimated the impurity effects of silicone glue on protein crystal growth. 相似文献
992.
We report an original solventless thermal crystallisation method to grow large needle‐like salicylic acid (SA) crystals of 10‐12 mm in length. The method is based on the utilization of nitrogen gaz flow on salicylic acid powder during heating just below melting point temperature for 24 h. Salicylic acid provides one of the best examples of a pharmaceutical substance used for cosmetics whose physical and chemical properties indicate hydrogen‐bond formation between the hydroxyl group and an adjacent oxygen atom of the same molecule. The structure of the crystals is confirmed by single crystal X‐ray diffraction; it is monoclinic, a = 4.93(2) Å, b = 11.23(5) Å, c = 11.56(6) Å, β = 90.77(4)° with the space group P 21/c. The macrocrystals formation using this method is new and represents an interesting finding for a wide range of applications to be developed in the fields of biotechnology and photonics (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
993.
Ito T Masuda Y Abe N Oyama M Sawa R Takahashi Y Chelladurai V Iinuma M 《Chemical & pharmaceutical bulletin》2010,58(10):1369-1378
Comprehensive re-investigation of the chemical constituents in the leaves of Vateria indica (Dipterocarpaceae) resulted in the isolation of a novel resveratrol dimeric dimer having a C(2)-symmetric structure, vateriaphenol F (1), and two new O-glucosides of resveratrol oligomers, vateriosides A (2) (resveratrol dimer) and B (4) (resveratrol tetramer), along with a new natural compound (3) and 33 known compounds including 26 resveratrol derivatives. The absolute structures were elucidated by spectroscopic analysis, including two dimensional NMR and circular dichroism (CD) spectra. 相似文献
994.
Kunieda M Nakaoka K Liang Y Miranda CR Ueda A Takahashi S Okabe H Matsuoka T 《Journal of the American Chemical Society》2010,132(51):18281-18286
It is well-known that the amphiphilic solutes are surface-active and can accumulate at the oil-water interface. Here, we have investigated the water and a light-oil model interface by using molecular dynamic simulations. It was found that aromatics concentrated in the interfacial region, whereas the other hydrocarbons were uniformly distributed throughout the oil phase. Similar to previous studies, such concentrations were not observed at pure aromatics-water interfaces. We show that the self-accumulation of aromatics at the oil-water interface is driven by differences in the interfacial tension, which is lower for aromatics-water than between the others. The weak hydrogen bonding between the aromatic rings and the water protons provides the mechanism for lowering the interfacial tension. 相似文献
995.
Toya H Okano K Takasu K Ihara M Takahashi A Tanaka H Tokuyama H 《Organic letters》2010,12(22):5196-5199
The enantioselective total synthesis of (-)- and (+)-petrosin is described. The union of two key segments was executed by Suzuki-Miyaura coupling. The quinolizidine rings were stereoselectively constructed via a diastereoselective Mannich reaction and an aza-Michael reaction. The 16-membered ring was constructed by ring-closing metathesis with the second-generation Grubbs catalyst. 相似文献
996.
Stepwise application of the Pd-catalyzed S(N)2' reaction and the desilylative S(E)2' reaction to the ambivalent 2-bromo-1-silyl-1,3-dienes provides a novel route to the highly enantioselective construction of tertiary and quaternary propargylic stereogenic centers via axially chiral allenylsilanes. 相似文献
997.
Takashi Komine Kota Takahashi Hiroshi Murakami Ryuji Sugita 《Journal of magnetism and magnetic materials》2010,322(19):2969-2972
In this study, the effect of exchange stiffness constant on current-driven domain wall motion in nanowires with in-plane magnetic anisotropy (IMA) and perpendicular magnetic anisotropy (PMA) has been investigated using micromagnetic simulation. The critical current density in a nanowire with IMA decreases as the exchange stiffness constant decreases because the domain wall width at the upper edge of the nanowire narrows according to the decrease of the exchange stiffness constant. On the other hand, the critical current density in a nanowire with PMA slightly decreases contrary to that of IMA although the domain wall width reasonably decreases as the exchange stiffness constant decreases. The slight reduction rate of the critical current density is due to the increase of the effective hard-axis anisotropy of PMA nanowire. 相似文献
998.
Yoji Imai Yasuhiko Takahashi Toshiya Kumagai 《Journal of magnetism and magnetic materials》2010,322(18):2665-43
Geometrical optimization of tetra-3d metal nitrides (Mn4N, Fe4N, Co4N, and Ni4N) has been performed and the relations of their energies (E) and their total magnetic moments (M) are obtained by plane-wave-basis density-functional calculations without any assumption of specific spin arrangement. The E vs. M relations obtained for Fe4N and Mn4N have a bimodal character. The ground state of Fe4N is a high-spin state, which would correspond to the ferromagnetic character, while that of Mn4N is a low-spin state, which would correspond to the observed ferrimagnetic character. Lattice constants and total magnetic moments of these tetra-3d metal nitrides are almost accurately predicted. From the spin-polarized densities of states curves, Co4N would have the largest spin polarization ratio of 0.88, which suggests Co4N can be a candidate material for ferromagnetic electrodes for spin-injection. 相似文献
999.
Y. Imai T. Akiike R. Tanaka H. Takahashi M. Hanawa I. Tsukada A. Maeda 《Physica C: Superconductivity and its Applications》2010,470(20):1038-1041
FeSe0.5Te0.5 thin films with PbO-type structure are successfully grown on MgO(1 0 0) and LaSrAlO4(0 0 1) substrates from FeSe0.5Te0.5 or FeSe0.5Te0.75 polycrystalline targets by pulsed-laser deposition. The film deposited on the MgO substrate (film thickness ∼ 55 nm) shows superconductivity at 10.6 K (onset) and 9.2 K (zero resistivity). On the other hand, the film deposited on the LaSrAlO4 substrate (film thickness ∼ 250 nm) exhibits superconductivity at 5.4 K (onset) and 2.7 K (zero resistivity). This suggests the strong influence of substrate materials and/or the c-axis length to superconducting properties of FeSe0.5Te0.5 thin films. 相似文献
1000.