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401.
Keiichi Motoyama Hidetoshi Arima Fumitoshi Hirayama Kaneto Uekama 《Journal of inclusion phenomena and macrocyclic chemistry》2006,56(1-2):75-79
The effects of 2,6-di-O-methyl-3-O-acetyl-β-cyclodextrins (DMA-β-CyD) with various degrees of substitution (DS) of an acetyl group of 1.5, 3.8, 6.3 and 7, which are abbreviated to DMA2-β-CyD, DMA4-β-CyD, DMA6-β-CyD and DMA7-β-CyD, respectively, on murine macrophage activation and endotoxin shock induced by lipopolysaccharide (LPS) were examined. Of four DMA-β-CyDs used in the present study, cytotoxicity of DMA-β-CyDs in RAW264.7 cells, a murine macrophage-like cell line, decreased with an increase in the DS values of DMA-β-CyD, and DMA7-β-CyD had no cytotoxicity on RAW264.7 cells up to 100 mM. DMA2-β-CyD and DMA7-β-CyD at the concentration of 5 mM had greater inhibitory effects on nitric oxide (NO) production in RAW264.7 cells stimulated with LPS than DMA4-β-CyD and DMA6-β-CyD. In addition, these inhibitory effects of DMA2-β-CyD and DMA7-β-CyD were concentration-dependent. In the in vivo study, all of the mice died within 12 h after intraperitoneal administration of the solution containing LPS and d-galactosamine. When 100 mM DMA7-β-CyD was concomitantly administered with both LPS and d-galactosamine intraperitoneally in mice, the survival rate significantly increased, but DMA4-β-CyD and DMA6-β-CyD did not. In conclusion, we revealed that DS values of DMA-β-CyDs strikingly affect not only the cytotoxic activity but also the inhibitory effects of LPS-induced NO production in RAW264.7 cells and fatality of endotoxin shock mice induced by LPS and d-galactosamine. These results suggest the potential use of DMA7-β-CyD as an antagonist of LPS-induced endotoxin shock. 相似文献
402.
We consider a partially hyperbolic diffeomorphism of a compact smooth manifold preserving a smooth measure. Assuming that
the central distribution is integrable to a foliation with compact smooth leaves we show that this foliation fails to have
the absolute continuity property provided that the sum of Lyapunov exponents in the central direction is not zero on a set
of positive measure. We also establish a more general version of this result for general foliations with compact leaves.
Partially supported by JSPS.
Partially supported by National Science Foundation grant #DMS-0088971 and U.S.-Mexico Collaborative Research grant 0104675. 相似文献
403.
We show that electron-nuclear spin coupling in semiconductor heterostructures is strongly modified by their potential inversion asymmetry. This is demonstrated in a GaAs quantum well, where we observe that the current-induced nuclear spin polarization at Landau-level filling factor nu=2/3 is completely suppressed when the quantum well is made largely asymmetric with gate voltages. Furthermore, we find that the nuclear spin relaxation rate is also modified by the potential asymmetry. These findings strongly suggest that even a very weak Rashba spin-orbit interaction can play a dominant role in determining the electron-nuclear spin coupling. 相似文献
404.
K. Saito Y. Hiratsuka A. Omata H. Makino S. Kishimoto T. Yamamoto N. Horiuchi H. Hirayama 《Superlattices and Microstructures》2007,42(1-6):172
Low-resistivity n-type ZnO thin films were grown by atomic layer deposition (ALD) using diethylzinc (DEZ) and H2O as Zn and O precursors. ZnO thin films were grown on c-plane sapphire (c- Al2O3) substrates at 300 C. For undoped ZnO thin films, it was found that the intensity of ZnO () reflection peak increased and the electron concentration increased from 6.8×1018 to 1.1×1020 cm−3 with the increase of DEZ flow rate, which indicates the increase of O vacancies () and/or Zn interstitials (Zni). Ga-doping was performed under Zn-rich growth conditions using triethylgallium (TEG) as Ga precursor. The resistivity of 8.0×10−4 Ω cm was achieved at the TEG flow rate of 0.24 μmol/min. 相似文献
405.
The Ru(bpy)32+*-MV2+ sensitization system formed within a Nafion film was linked with in vitro bacterial luciferase reaction in the presence of a blue fluorescent protein. The electron released from the excited triplet Ru(bpy)32+* was transferred to the luciferase catalytic cycle with the fluorescent protein via electron relay, resulting in sensitization of the fluorescence protein. 相似文献