David Butterfield | PubMed Health

PubMed2005

Controlled placement of CdSe nanoparticles in diblock copolymer templates by electrophoretic deposition.

An electrophoretic deposition process is shown to be an effective means of placing CdSe nanoparticles into nanopores and nanotrenches in templates prepared from polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA) diblock copolymers. CdSe nanoparticles covered with alpha,omega-thiocarboxylic acid ligands were used in these studies, and an electric field was used to drive the nanoparticle deposition. Photoluminescence of the quantum dots was maintained within the nanostructures.

Adsorption↗

PubMed2003

Fluids from aging ocean crust that support microbial life.

Little is known about the potential for life in the vast, low-temperature (<100 degrees C) reservoir of fluids within mid-ocean ridge flank and ocean basin crust. Recently, an overpressured 300-meter-deep borehole was fitted with an experimental seal (CORK) delivering crustal fluids to the sea floor for discrete and large-volume sampling and characterization. Results demonstrate that the 65 degrees C fluids from 3.5-million-year-old ocean crust support microbial growth. Ribosomal RNA gene sequence data indicate the presence of diverse Bacteria and Archaea, including gene clones of varying degrees of relatedness to known nitrate reducers (with ammonia production), thermophilic sulfate reducers, and thermophilic fermentative heterotrophs, all consistent with fluid chemistry.

Ammonia↗