IBEX: an iterative immunolabeling and chemical bleaching method for high-content imaging of diverse tissues.

High-content imaging is needed to catalog the variety of cellular phenotypes and multicellular ecosystems present in metazoan tissues. We recently developed iterative bleaching extends multiplexity (IBEX), an iterative immunolabeling and chemical bleaching method that enables multiplexed imaging (>65 parameters) in diverse tissues, including human organs relevant for international consortia efforts. IBEX is compatible with >250 commercially available antibodies and 16 unique fluorophores, and can be easily adopted to different imaging platforms using slides and nonproprietary imaging chambers.

Brain findings associated with risperidone in rhesus monkeys: magnetic resonance imaging and pathology perspectives.

Brain changes associated with risperidone, a dopamine-2/serotonin-2 receptor antagonist, have been documented in rats and humans, but not in nonhuman primates. This study characterized brain changes associated with risperidone in nonhuman primates. Rhesus monkeys were orally administered risperidone in a dose-escalation paradigm up to a maximum tolerated dose of 0.

Optical Fluorescence Microscopy for Spatially Characterizing Electron Transfer across a Solid-Liquid Interface on Heterogeneous Electrodes.

Heterogeneous catalytic materials and electrodes are used for (electro)chemical transformations, including those important for energy storage and utilization. Due to the heterogeneous nature of these materials, activity measurements with sufficient spatial resolution are needed to obtain structure/activity correlations across the different surface features (exposed facets, step edges, lattice defects, grain boundaries, etc.).

Plasmonic color analysis of Ag-coated black-Si SERS substrate.

Red-Green-Blue (RGB) dark-field imaging can direct the choice of laser excitation for Raman enhancements on nanostructured plasmonic surfaces. Here we demonstrate that black silicon (b-Si) is a structured surface that has been shown to effectively absorb broad wavelengths of light, but also enables surface enhanced Raman scattering (SERS) when coated with silver (Ag). Coating b-Si with increasing amounts of Ag results in increased dark-field scattering at discrete frequencies associated with localized plasmon resonances.

Experimental correlation of electric fields and Raman signals in SERS and TERS.

Enhanced Raman scattering from plasmonic nanostructures associated with surface enhanced (SERS) and tip enhanced (TERS) is seeing a dramatic increase in applications from bioimaging to chemical catalysis. The importance of gap-modes for high sensitivity indicates plasmon coupling between nanostructures plays an important role. However, the observed Raman scattering can change with different geometric arrangements of nanoparticles, excitation wavelengths, and chemical environments; suggesting differences in the local electric field.

Nitrile vibrations as reporters of field-induced phase transitions in 4-cyano-4'-pentylbiphenyl (5CB).

4-Cyano-4'-pentylbiphenyl (5CB) is a liquid crystal forming compound with a terminal nitrile group aligned with the long axis of the molecule. Simulations of condensed-phase 5CB were carried out both with and without applied electric fields to provide an understanding of the Stark shift of the terminal nitrile group. A field-induced isotropic-nematic phase transition was observed in the simulations, and the effects of this transition on the distribution of nitrile frequencies were computed.

Imaging Electric Fields in SERS and TERS Using the Vibrational Stark Effect.

Electric fields associated with Raman enhancements are typically inferred from changes in the observed scattering intensity. Here we use the vibrational Stark effect from a nitrile reporter to determine the electric field dependent frequency shift of cyanide (CN) on a gold (Au) surface. Electroplated Au surfaces with surface enhanced Raman (SERS) activity exhibit larger Stark shifts near the edge and in areas with large roughness.

The role of lateral tension in calcium-induced DPPS vesicle rupture.

We assess the role of lateral tension in rupturing anionic dipalmitoylphosphatidyserine (DPPS), neutral dipalmitoylphosphatidylcholine (DPPC), and mixed DPPS-DPPC vesicles. Binding of Ca(2+) is known to have a significant impact on the effective size of DPPS lipids and little effect on the size of DPPC lipids in bilayer structures. In the present work we utilized laser transmission spectroscopy (LTS) to assess the effect of Ca(2+)-induced stress on the stability of the DPPS and DPPC vesicles.