Search

Microtubules are among bio-polymers providing vital functions in dynamic cellular processes. Artificial organization of these bio-polymers is a requirement for transferring their native functions into device applications. Using electrophoresis, we achieve an accumulation of microtubules along a metallic glass (Pd42.5Cu30Ni7.5P20) microwire in solution. According to an estimate based on migration velocities of microtubules approaching the wire, the electrophoretic mobility of microtubules is around 10-12 m2/Vs. This value is four orders of magnitude smaller than the typical mobility reported previously. Fluorescence microscopy at the individual-microtubule level shows microtubules aligning along the wire axis during the electric field-induced migration. Caseintreated electrodes are effective to reversibly release trapped microtubules upon removal of the external field. An additional result is the condensation of secondary filamentous structures from oriented microtubules. [ABSTRACT FROM AUTHOR]

The phase relation between supercooled liquid silicon (l-Si) and amorphous silicon (a-Si) is discussed based on experimental results. Electrostatically levitated l-Si samples were supercooled down to low temperatures, 300 K below the melting temperature (Tcl: 1683 K), and solidified accompanied by the release of latent heat. It was found that solidified Si samples melted again at 1480 K caused by the latent heat. Also, it was found that the Si samples that rapidly quenched near the solidification temperature contained a large amount of a-Si with tetrahedral coordination. These two findings show that the supercooled l-Si samples solidified into a-Si and a-Si melted, confirming the idea of a first-order phase transition between two metastable phases proposed by Turnbull et al. [Metall. Mater. Trans. A 29, 1825 (1998)]. [ABSTRACT FROM AUTHOR]

Atomic force microscope (AFM) makes it possible to image the surface morphological evolutions of the Zr50Cu40Al10 bulk metallic glass (BMG). The heating in vacuum leads to the creation of nanoclusters and the significant structural changes driven by viscous flow. Auger electron spectroscopy confirms that the nanoclusters correspond to zirconium oxide. Furthermore, the nanoclusters do not influence the crystallization process of the BMG but the viscous flow is crucial to surface modification. The temperature dependent AFM observation combined with chemical analysis is a new protocol to study fundamental properties of BMG surfaces. [ABSTRACT FROM AUTHOR]