Abstract: Provided is an activatable probe that undergoes intramolecular cyclization and subsequent aggregation in apoptotic tumor cells upon peptidase-initiated, and most advantageously caspase-3, activation. These caspase-sensitive nano-aggregation probes (C-SNAFs) are generally biocompatible, possess NIR spectral properties or may serve as PET or MRI imaging agents, and have a mechanism of target-mediated nanostructure self-assembly amenable to in vivo use. The probes encompass biocompatible condensation chemistry products that comprise D-cysteine and 2-cyano-6-hydroxyquinoline (CHQ) moieties linked to an amino-luciferin scaffold, and which can be activated by a two-step reaction requiring caspase-3/7-mediated cleavage of an aspartate-glutamate-valine-aspartate (L-DEVD) capping peptide and the free intracellular thiol-mediated reduction of the disulfide bond.

Abstract: Provided is an activatable probe that undergoes intramolecular cyclization and subsequent aggregation in apoptotic tumor cells upon peptidase-initiated, and most advantageously caspase-3, activation. These caspase-sensitive nano-aggregation probes (C-SNAFs) are generally biocompatible, possess NIR spectral properties or may serve as PET or MRI imaging agents, and have a mechanism of target-mediated nanostructure self-assembly amenable to in vivo use. The probes encompass biocompatible condensation chemistry products that comprise D-cysteine and 2-cyano-6-hydroxyquinoline (CHQ) moieties linked to an amino-luciferin scaffold, and which can be activated by a two-step reaction requiring caspase-3/7-mediated cleavage of an aspartate-glutamate-valine-aspartate (L-DEVD) capping peptide and the free intracellular thiol-mediated reduction of the disulfide bond.

Abstract: An evacuated envelope includes front and back walls and a plurality of spaced, parallel support walls between and perpendicular thereto. The support walls form therebetween a plurality of channels. In each of the channels is at least one beam guide which confines electrons injected into the guide in a beam which travels along the beam guide but permits selective deflection of the beam out of the guide toward a phosphor screen on the inner surface of the front wall. A gun structure extends across one end of the channels for generating electrons and directing the electrons into the beam guides. The gun structure includes a thermionic emissive cathode extending across the ends of the channels and support members at spaced points along the cathode which support the cathode within the envelope but allow movement of the cathode with respect to the support members as a result of expansion or contraction of the cathode.