Hydrogels that degrade under appropriate conditions of pH and temperature by virtue of crosslinking compounds that cleave through an elimination reaction are described. The hydrogels may be used for delivery of various agents, such as pharmaceuticals. This invention provides hydrogels that degrade to smaller, soluble components in a non-enzymatic process upon exposure to physiological conditions and to methods to prepare them. The hydrogels are prepared from crosslinking agents that undergo elimination reactions under physiological conditions, thus cleaving the crosslinking agent from the backbone of the hydrogel. The invention also relates to the crosslinking agents themselves and intermediates in forming the hydro gels of the invention. The biodegradable hydro gels prepared according to the methods of the invention may be of use in diverse fields, including biomedical engineering, absorbent materials, and as carriers for drug delivery.

The present invention provides novel compounds and methods for hydrocyanines derived from near-infrared cyanine dyes, as reactive oxygen species probes in imaging. In certain embodiments, the present invention provides reduced dyes as substrates for ELISA and Western blots.

Sterile and non-toxic pharmaceutical compositions of near IR, closed chain, sulfo-cyanine dyes and methods for visualizing tissue under illumination with near-infrared radiation are provided.

An object of the present invention is to provide a color developing composition which develops colors in a high density and does not significantly discolor when aged, a lithographic printing plate precursor which has excellent plate-inspecting properties by means of color development and is capable of maintaining strong color development even when aged after color development, a plate making method for a lithographic printing plate in which the lithographic printing plate precursor is used, and a new compound that can be preferably used as a color developer.

The color developing composition of the present invention includes a compound represented by Formula 1. The compound in the present invention is represented by Formula 1. In Formula 1, R.sup.1 represents a group in which an R.sup.1O bond is cleaved by heat or exposure to infrared rays.

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Compounds used as labels with properties comparable to known fluorescent compounds. The compounds can be conjugated to proteins and nucleic acids for biological imaging and analysis. Synthesis of the compounds, formation and use of the conjugated compounds, and specific non-limiting examples of each are provided.

Provided herein are heptamethine cyanine dyes having a large Stokes shift, and the salts and conjugates thereof. Also provided are methods of using and making such large Stokes shift dyes as fluorescence resonance energy transfer (FRET) acceptors or donors.

The present invention provides for heptamethine cyanine dyes that possess both nuclear and near-infrared imaging capabilities. These dyes can be used for imaging, targeting and detecting tumors in patients.

A photoelectric conversion element including a photoconductor layer, wherein the photoconductor layer contains semiconductor fine particles carrying a metal complex dye of Formula (I); a metal complex dye, a dye solution, a dye-adsorbed electrode, a dye-sensitized solar cell, and a method for producing the solar cell:
M(LD)(LA).Math.(CI) Formula (I) wherein M represents a metal ion; LD represents a tridentate ligand of formulas (DL-1) to (DL-4); LA represents a specific tridentate ligand; and CI represents a counter ion: ##STR00001## Y.sup.1 and Y.sup.2 represent an oxygen, sulfur, nitrogen, or phosphorus atom; AD and BD represent a hydrocarbon or hetero ring; L represents a linking group of formulas (L-1) to (L-4); and Ra and Rb represent a substituent, ##STR00002## X represents a nitrogen or carbon atom; CD represents hetero ring; T represents O, S, NR.sup.L2 or PR.sup.L3; R.sup.L1 to R.sup.L3 represent a hydrogen atom or a substituent; and Alk represents an alkylene group.

A photosensitizer is a dye represented by the following formula (I) or its salt. In the following chemical formula, m represents an integer of 0 through 4, and n represents an integer of 0 or 1, and p represents an integer of 0 to 2. R.sub.1, R.sub.2 and R.sub.3 represent a hydrogen atom, an alkyl group, an aryl group or the like. R.sub.4, R.sub.4, R.sub.4, R.sub.5, R.sub.6, R.sub.7, R.sub.8 and R.sub.9 represent a hydrogen atom, an alkyl group and the like. X represents a carbonyl group or the like. Z.sub.1 and Z.sub.2 represent a carboxyl group or the like:

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The invention relates to a family of dyes which fluoresce in the UV-VIS, far red and near infrared wavelengths of the spectrum and possess asymmetric lipophilic alkyl chains. The dyes of the invention are soluble in commercially available membrane staining vehicles, are useful as probes for rapidly staining lipophilic structures such as membranes in cells or isolated from cells, and are well-retained therein. Methods of utilizing the dyes to detect stained cells both in vivo and in vitro are also disclosed.