Welcome to the internet hub of the Materials Research Science and Engineering Centers (MRSEC). This website provides organized information and resources at the various MRSECs for the international scientific, industrial, and educational materials research and development communities.
Rodlike fd viruses in an aqueous
solution, along with polymers that produce an attractive force between the
virus particles, have been observed in laboratory experiments to self-assemble
into a variety of geometric structures including twisted ribbons (see the schematic
illustration and microscope picture to the right). We have developed a
theoretical model which explains the properties of these ribbons on the basis
of very general features of the fd rods. The theory yields
predictions in good agreement with experiment, namely, (a) a phase diagram with a first-order transition
from flat membranes to twisted ribbons, (b) the ratio of the ribbon's
pitch to width, (c) the tilt angle of the rods at the edge of the
ribbon. The theory has also demonstrated
the importance of molecular chirality ("twisting-handedness") in the formation of
the ribbons, as well as the tendency of fd rods to assemble into
structures with negative Gaussian curvature (as in a saddle shape).
Cilia
and flagella are tiny waving filaments with important functions in humans, such
as clearing our airways. A 3D electron microscopy study of the normal (WT) and
mutant varieties of flagella has revealed new details of the structure, protein
composition, and connections between neighboring components formed by a crucial
structural complex of this biological nanomachine,
the "nexin-dynein
regulatory complex" (N-DRC), which is shown in color on the left. In the poorly
moving mutants, this structure is damaged or almost missing. This opens the way
for building a new mechanical model of this device, and how it functions, along
with mechanical testing of individual cilia and flagella, normal and mutant, in
the Brandeis multi-mode optical microscopy laboratory.
Centers
of Excellence for Materials Research and Innovation (CEMRIs) provide
sustained support of interdisciplinary materials research and education
of the highest quality while addressing fundamental problems in science
and engineering. CEMRIs address research of a scope and complexity
requiring the advantages of scale and interdisciplinarity provided by a
campus-based research center.
Xavier University of Louisiana
and New York University have received a $3 million grant from the
National Science Foundation to bolster diversity among materials
scientists through collaborative research and curriculum development.
The award was one of eight awarded this year under NSF’s Partnerships
for Research and Education in Materials (PREM) program and funded
through the American Recovery and Reinvestment Act (ARRA).
Rodlike fd viruses in an aqueous
solution, along with polymers that produce an attractive force between the
virus particles, have been observed in laboratory experiments to self-assemble
into a variety of geometric structures including twisted ribbons (see the schematic
illustration and microscope picture to the right). We have developed a
theoretical model which explains the properties of these ribbons on the basis
of very general features of the fd rods. The theory yields
predictions in good agreement with experiment, namely, (a) a phase diagram with a first-order transition
from flat membranes to twisted ribbons, (b) the ratio of the ribbon's
pitch to width, (c) the tilt angle of the rods at the edge of the
ribbon. The theory has also demonstrated
the importance of molecular chirality ("twisting-handedness") in the formation of
the ribbons, as well as the tendency of fd rods to assemble into
structures with negative Gaussian curvature (as in a saddle shape).
Cilia
and flagella are tiny waving filaments with important functions in humans, such
as clearing our airways. A 3D electron microscopy study of the normal (WT) and
mutant varieties of flagella has revealed new details of the structure, protein
composition, and connections between neighboring components formed by a crucial
structural complex of this biological nanomachine,
the "nexin-dynein
regulatory complex" (N-DRC), which is shown in color on the left. In the poorly
moving mutants, this structure is damaged or almost missing. This opens the way
for building a new mechanical model of this device, and how it functions, along
with mechanical testing of individual cilia and flagella, normal and mutant, in
the Brandeis multi-mode optical microscopy laboratory. 