An organic acid precursor having a structural moiety of the following formula ##STR1## bonded to a carbon atom. This acid precursor is useful as a development stopping agent in a photographic heat-developable process.

Catalytic ortho-alkylation process which comprises reacting a phenolic compound with an alcohol in the presence of a catalyst composite comprising a calcination residue derived from a catalyst preform prepared from an admixture of (1) a magnesium carbonate and/or magnesium hydroxide, (2) a manganese compound, and (3) a complex of poly(2,6-dimethyl-1,4-phenylene oxide) and a solvent selected from dichloromethane, dibromomethane, bromochloromethane and mixtures thereof.

The present invention provides new compound, 10-substituted-5,9-dioxatricyclo[6.4.0.0.sup.2,6 ]dodecane-4-one, which is very useful as an intermediate for prostaglandin synthesis.

The compounds of the formula I ##STR1## are precursors for organoleptic and antimicrobial compounds. The latter are generated in the presence of skin bacteria, enzymes or acidic or alkaline conditions. One precursor molecule can provide one or more different compounds.

The service life of fiber-reinforced polyimide composites in a high temperature oxidative environment is extended by coating with a polyimide coating precursor solution that is synthesized by reacting an aromatic dianhydride with an aromatic diamine in a non-reactive solvent. The reactive solution is heated to a temperature sufficent to reduce its viscosity prior to its use as a coating. Preferably, a mixture of meta-phenylenediamine and para-phenylenediamine is reacted with biphenyldianhydride ...

A population of T lymphocyte precursor cells is disclosed. In bone marrow, the earliest identifiable T lymphocyte precursor is CD34.sup.+, CD7.sup.+ and Leu 8.sup.+++. Methods of isolation and methods of therapeutic use of such cells also are disclosed.

A population of T lymphocyte precursor cells is disclosed. In bone marrow, the earliest identifiable T lymphocyte precursor is CD34.sup.+, CD7.sup.+ and Leu 8.sup.+++. Methods of isolation and methods of therapeutic use of such cells also are disclosed.

An activator-stabilizer precursor compound having an acid portion which is an alpha-sulfonylacetate is useful in a photographic composition which is responsive to heat for processing. The activator-stabilizer precursors are characterized in that their acid byproducts have reduced toxicity and volatility and are substantially inert in a processed photographic element.

An aroma precursor composition comprising: a hydrogen sulfide precursor, preferably cysteine; a dimethyl sulfide precursor, preferably S-methyl methionine; and an edible proteinaceous material, preferably soy protein. Upon heating or cooking in the presence of water, the precursor composition generates an aroma surprisingly reminiscent of cooked beef. Preferably, the precursor composition is substantially dry until ready to cook, then an effective amount of water is added thereto, whereby, upon ...

A technique suitable for cloning a cDNA having a base sequence coding for the ACTH/LPH precursor is disclosed. The invention is exemplified by the cloning of a cDNA fragment comprising a base sequence coding for the endorphin region. The fragment, hereinafter termed the endorphin gene cDNA sequence, was obtained from cultured mouse pituitary tumor cells known to produce the ACTH/LPH precursor protein.