BIOTECHNOLOGY -- Regenerating skin, muscle . . .
Researchers at the Bio-SANS instrument at the High Flux Isotope Reactor used contrast variation and small-angle neutron scattering to get a first insight into how macromolecules form single polyelectrolyte chains in synthetic complexes. The unique properties of polyelectrolyte materials are of intense interest in biotechnology for making a type of membrane -- three-dimensional bio-scaffolds to grow cells for regenerating skin, muscle and even organs. Little is known about how the component chains in polyelectrolyte complexes form themselves, whether as strings or as coils, inside the bulk material. The SANS work will assist researchers in tuning thickness, uniformity, stability, swelling, permeability and other important variables. The results could open the door to multiple future applications.
[Written by Agatha Bardoel; media contact: Ron Walli, (865) 576-0226; wallira@ornl.gov]
HEALTH -- Virus response to pH changes . . .
The Sindbis virus, or SINV, is the prototype for viruses spread by insects, which cause some of the most devastating and widespread diseases among humans. Exposure to low pH (acidic) conditions causes dramatic changes in the three-dimensional structure of SINV that can help the virus membrane fuse with a cell membrane when the pH returns to normal. Small-angle neutron scattering at Oak Ridge National Laboratory's High Flux Isotope Reactor is improving understanding of how SINV delivers its infectious RNA into host cells by revealing details of these structural changes. When the pH is reduced from 7.2 to 6.4, the RNA in the SINV core changes, and much of the protein associated with the interior liquid bi-layer moves to the exterior of the virus particle. The SANS data, the first to show how the RNA and lipid components interact with the virus proteins as the pH changes, improve understanding of the effects of pH on SINV, which is an excellent model for studies of virus structure and function.
[Written by Deborah Counce; media contact: Ron Walli, (865) 576-0226; wallira@ornl.gov]
FUSION -- Supporting ITER systems . . .
U.S. ITER researchers at the Fusion Pellet Fueling Lab at Oak Ridge National Laboratory are developing and testing pellet injector technology for fueling and controlling the hot plasma in the ITER tokamak experimental reactor. Current research is focused on U.S. ITER contributions to fueling, disruption mitigation and vacuum systems. The work includes pellets and injectors to both fuel the plasma and control plasma edge localized instabilities. A novel pellet extruder has been developed to provide a continuous flow of solid hydrogen that can be cut into precisely sized pellets. Finally, a gas injection system to rapidly bring down a turbulent plasma when needed, a diagnostic to measure pellet mass in flight, and a roughing pump system to pump exhaust to the processing plant complete recent tokamak technology.
[Written by Agatha Bardoel; media contact: Ron Walli, (865) 576-0226; wallira@ornl.gov]
NEUTRONS -- Examining nanoporous carbons . . .
Several recent papers describe how Oak Ridge National Laboratory researcher Yuri Melnichenko and his collaborators continue to use neutrons and small-angle neutron scattering to bore through geological materials such as nanoporous carbons to understand their unique properties as storage media for greenhouse gases and for hydrogen in fuel cells used in transportation. The SANS method also shows promise for strategies for extracting a cleaner form of energy -- methane gas -- from hard shales. In other recent work on the behavior of CO2 confined in nanopores, the researchers turned to a silica aerogel model system as a good matrix material. They varied the silica aerogel surface chemistry to see how this influenced the phase behavior of the molecules of stored CO2.
[Written by Agatha Bardoel; media contact: Ron Walli, (865) 576-0226; wallira@ornl.gov]