Assembly and charge transfer in hybrid TiO(2) architectures using biotin-avidin as a connector

Exploiting the presence of undercoordinated surface Ti atoms at the tips of TiO2 nanorods and the dopamine selectivity for these Ti surface states, biotin was conjugated to TiO2 nanocrystallites using dopamine as a bridging linker. Using abiotin-avidin complex as a connector the "tip-to-tip" assembly of 400 nm elongated TiO2 rods was obtained. The photoexcitation of avidin-TiO2 hybrids resulted in the transfer of holes from nanocrystallites to protein and consequent oxidation of avidin, most probably at tyrosine 33.     

The discretized flow on domains of attraction: a structural stability result

It is well known that, for stepsize sufficiently small, compactattractors of ordinary differential equations persist underdiscretization. The present paper describes the structure ofthe discrete-time dynamical system obtained via discretizationon A(M_h)\M_h where M_h is the approximate attractor and A(M_h)is its domain of attraction. The existence of a smooth embeddinginto a continuous-time parallelizable flow is proved. The constructioncan be used to define sections for discretizations and can beinterpreted as a justification of the method of modified equations.     

Aqueous self-assembly of unsymmetric Peptide bolaamphiphiles into nanofibers with hydrophilic cores and surfaces

Unsymmetric peptide bolaamphiphiles that incorporate (l-glutamyl)3glycine at one terminus and either tetraethylene glycol or aspartic acid at the other were found to form hydrogels at low wt %, presumably by self-assembling into nanofibers presenting (l-glutamyl)3glycine at their surfaces and burying the second headgroup at their cores. Transmission electron microscopy measurements on 1 wt % gels negatively stained with phosphotungstic acid and positively stained with uranyl acetate show one-dimensional objects with diameters of 5 nm and lengths in excess of 1 mum. Circular dichroism and solid-state FTIR spectra indicate the adoption of beta-sheet structure within the nanofibers.