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991.
992.
Yamauchi M Abe R Tsukuda T Kato K Takata M 《Journal of the American Chemical Society》2011,133(5):1150-1152
Body-centered-cubic type CuPd nanoalloys were synthesized by a chemical reduction method. Photocatalytic hydrogen evolution and nitrate reduction were simultaneously examined over CuPd nanoalloys deposited on TiO(2) (CuPd/TiO(2)). The efficiency of hydrogen evolution over CuPd/TiO(2) was better than that over Pd/TiO(2). As for nitrate reduction, ammonia was selectively (78%) produced with hydrogen generated photocatalytically over CuPd/TiO(2). The continuous generation of nascent hydrogen atoms on the surface of the CuPd nanoalloy, where Cu and Pd are homogeneously mixed, led to the high selectivity for ammonia. 相似文献
993.
Han SH Song YK Cho FH Ryu S Cho G Song YQ Cho H 《Journal of magnetic resonance (San Diego, Calif. : 1997)》2011,212(2):386-393
Non-invasive measurements of structural orientation provide unique information regarding the connectivity and functionality of fiber materials. In the present study, we use a capillary model to demonstrate that the direction of fiber structure can be obtained from susceptibility-induced magnetic field anisotropy. The interference pattern between internal and external magnetic field gradients carries the signature of the underlying anisotropic structure and can be measured by MRI-based water diffusion measurements. Through both numerical simulation and experiments, we found that this technique can determine the capillary orientation within 3°. Therefore, susceptibility-induced magnetic field anisotropy may be useful for an alternative tractography method when diffusion anisotropy is small at higher magnetic field strength without the need to rotate the subject inside the scanner. 相似文献
994.
Won-Hee Ryu Dong-Wook Han Won-Keun Kim Hyuk-Sang Kwon 《Journal of nanoparticle research》2011,13(10):4777-4784
In this article, a catalytic-ion assisted hydrothermal method has recently been developed for synthesis of hierarchical manganese
dioxide nanostructures. In this study, various shapes of hierarchical MnO2 (nanorod, nanothorn sphere, sphere) were successfully synthesized using the hydrothermal method with quantitative control
of Al3+ in solution. The aspect ratio of aligned nanorods on the nanothorn sphere was easily controlled by the amount of Al3+ in the MnSO4 and (NH4)2S2O8 aqueous solution. Furthermore, we found that Al3+ species in the solution acted as a functional doping species into 2 × 2 tunnels of α-MnO2 and also as a catalyst. The formation mechanism of hierarchical MnO2 structures as a function of Al3+ concentration during hydrothermal reaction was sufficiently investigated, and the role of Al3+ as catalyst and doping species in the solution was discussed. 相似文献
995.
Ill Ryu Jang Wook Choi William D. Nix 《Journal of the mechanics and physics of solids》2011,59(9):1717-4025
We use a unique transmission electron microscope (TEM) technique to show that Si nanowires (NWs) with diameters in the range of a few hundred nanometers can be fully lithiated and delithiated without fracture, in spite of the large volume changes that occur in this process. By analyzing the stresses associated with lithiation and delithiation we conclude that the process does not occur by the growth of discrete crystalline phases; rather it occurs by amorphization of the Si NWs followed by diffusion of Li into the structure. By accounting for the large deformation associated with this process and by including the effects of pressure gradients on the diffusion of Li, we show that Si NWs with diameters less than about 300 nm could not fracture even if pre-existing cracks were present in the NW. These predictions appear to be in good agreement with the experiment. 相似文献
996.
A solvatochromic and non-fluorescent acid-base indicator, methyl orange (MO) was applied to colorimetric discrimination between adenosine triphosphate (ATP) and the corresponding diphosphate (ADP) at pH 2.0 in the presence of L-glutamic acid-derived cationic peptide amphiphile 1. This method is based on the fact that the amphiphile 1 can prevent MO from protonation even at pH 2.0. No similar colour change was observed when ADP was added instead of ATP under the same conditions. The effect of the molecular structure of several peptide amphiphiles and dyes was also investigated. 相似文献
997.
We establish optimal gradient estimates in Orlicz space for a nonhomogeneous elliptic equation of higher order with discontinuous coefficients on a nonsmooth domain. Our assumption is that for each point and for each sufficiently small scale the coefficients have small mean oscillation and the boundary of the domain is sufficiently close to a hyperplane. As a consequence we prove the classical Wm,p, m=1,2,…, 1<p<∞, estimates for such a higher order equation. Our results easily extend to higher order elliptic and parabolic systems. 相似文献
998.
999.
Lee JH Lee Y Ryu H Kang DW Lee J Lazar J Pearce LV Pavlyukovets VA Blumberg PM Choi S 《Journal of computer-aided molecular design》2011,25(4):317-327
The transient receptor potential vanilloid subtype 1 (TRPV1) is a non-selective cation channel composed of four monomers with
six transmembrane helices (TM1–TM6). TRPV1 is found in the central and peripheral nervous system, and it is an important therapeutic
target for pain relief. We describe here the construction of a tetrameric homology model of rat TRPV1 (rTRPV1). We experimentally
evaluated by mutational analysis the contribution of residues of rTRPV1 contributing to ligand binding by the prototypical
TRPV1 agonists, capsaicin and resiniferatoxin (RTX). We then performed docking analysis using our homology model. The docking
results with capsaicin and RTX showed that our homology model was reliable, affording good agreement with our mutation data.
Additionally, the binding mode of a simplified RTX (sRTX) ligand as predicted by the modeling agreed well with those of capsaicin
and RTX, accounting for the high binding affinity of the sRTX ligand for TRPV1. Through the homology modeling, docking and
mutational studies, we obtained important insights into the ligand-receptor interactions at the molecular level which should
prove of value in the design of novel TRPV1 ligands. 相似文献
1000.
Lateral force microscopy (LFM) is an application of atomic force microscopy (AFM) to sense lateral forces applied to the AFM probe tip. Recent advances in tissue engineering and functional biomaterials have shown a need for the surface characterization of their material and biochemical properties under the application of lateral forces. LFM equipped with colloidal probes of well-defined tip geometries has been a natural fit to address these needs but has remained limited to provide primarily qualitative results. For quantitative measurements, LFM requires the successful determination of the lateral force or torque conversion factor of the probe. Usually, force calibration results obtained in air are used for force measurements in liquids, but refractive index differences between air and liquids induce changes in the conversion factor. Furthermore, in the case of biochemically functionalized tips, damage can occur during calibration because tip-surface contact is inevitable in most calibration methods. Therefore, a nondestructive in situ lateral force calibration is desirable for LFM applications in liquids. Here we present an in situ hydrodynamic lateral force calibration method for AFM colloidal probes. In this method, the laterally scanned substrate surface generated a creeping Couette flow, which deformed the probe under torsion. The spherical geometry of the tip enabled the calculation of tip drag forces, and the lateral torque conversion factor was calibrated from the lateral voltage change and estimated torque. Comparisons with lateral force calibrations performed in air show that the hydrodynamic lateral force calibration method enables quantitative lateral force measurements in liquid using colloidal probes. 相似文献