Fuming method for micropatterning structures on Langmuir-Blodgett films.

Lipid monolayers of L-alpha-dipalmitoylphosphatidylcholine (DPPC) are used to pattern substrates using the Langmuir-Blodgett (LB) technique. Lipid monolayers are deposited onto freshly cleaved mica surfaces or glass capillaries under conditions that lead to distinct patterns in the film. Exposure of the supported monolayer to ethyl 2-cyanoacrylate fumes leads to preferential polymerization in the more hydrated regions of the patterned monolayer.

Characterization of power induced heating and damage in fiber optic probes for near-field scanning optical microscopy.

Tip-induced sample heating in near-field scanning optical microscopy (NSOM) is studied for fiber optic probes fabricated using the chemical etching technique. To characterize sample heating from etched NSOM probes, the spectra of a thermochromic polymer sample are measured as a function of probe output power, as was previously reported for pulled NSOM probes. The results reveal that sample heating increases rapidly to approximately 55-60 degrees C as output powers reach approximately 50 nW.

The role of nuclear envelope calcium in modifying nuclear pore complex structure.

Some of the most important trafficking processes in cells involve transport across the nuclear envelope. Whether it is the import of transcription factors or the export of RNA, the only known portal across the double lipid bilayer that forms the nuclear envelope are the macromolecular pores known as nuclear pore complexes (NPCs). Understanding how signals influence the conformation of the NPC is important for testing models of, and perhaps modifying, transport across the nuclear envelope.

Nuclear side conformational changes in the nuclear pore complex following calcium release from the nuclear membrane.

Changes in nuclear pore complex (NPC) structure are studied following treatments modifying the cisternal calcium levels located between the two lipid bilayers that together form the nuclear envelope. Since the NPC forms the only known passageway across the nuclear envelope, it plays a central role in nucleocytoplasmic transport. Understanding the origin of conformational changes that may affect this trafficking or modify cargo interactions with the NPC is, therefore, necessary to completely understand the function of these complex molecules.

Activation of ryanodine receptors in the nuclear envelope alters the conformation of the nuclear pore complex.

Nuclear pore complexes (NPCs) are supramolecular protein pores that traverse the nuclear envelope and form the only known direct route of transport between the cytoplasmic and nuclear spaces. Detailed studies have identified both active and passive mechanisms of transport through the NPC and structural studies have revealed its three-dimensional architecture. Under certain conditions, structural studies have found evidence for a mass in the central pore of the NPC whose identity remains unclear.