Abstract: The invention relates to the synthesis of polyoxygenated nitrogen systems, comprising reactions between enamines of 1,3-dioxan-5-ones and nitroolefins. More specifically, the invention relates to the reaction between enamines having formula II which are derived from 1,3-dioxan-5-ones I and nitroolefins having formula III. In this way, novel polyoxygenated nitrogen systems are generated having formula IV and V, which, as they are or following simple transformations, constitute synthetic intermediates and/or analogues of different systems of proven biological/pharmacological interest, such as certain antibiotics, or tetrodotoxin, pancratistatin or the analogues thereof. The aforementioned reactions involve the use of enamines II in Michael-type addition reactions and in direct annealing processes with double acceptor systems at relative positions 1, 3. Said N acceptors include nitroolefins III, wherein R?CHO (alphanitroenals).

Abstract: The present invention relates to a process of obtaining taxosteroids and precursors thereof from the hydrindane bicyclic ring system. The compounds have a tetracyclic system which combines the structural characteristics of taxanes, such as the bicyclo[5.3.1]undecane system (cycles A and B), fused to a six-membered ring (C), and of steroids, such as the CD bicycle, the A ring and the side chain (Sc). The process of preparing the compounds and their application as compositions with pharmacological properties of interest are described.

Abstract: The present invention relates to a process of obtaining type II dehydroquinase enzyme inhibitors and the precursors thereof from (?)-quinic acid. The described compounds have a carboxycyclohexene structure. The process of preparing the compounds and their application as compositions with pharmacological properties and herbicides of interest are described.

Abstract: A process of obtaining silicon nitride (Si3N4) surface coatings on ceramic pieces and components by impregnation of the surfaces of the ceramic pieces with silicon powder suspensions with a particle size preferably less than 200 ?m. The thickness of the coatings depends on the impregnation time and on the properties of the slip and the ceramic piece. The subsequent nitridation of the coating by thermal treatment at temperatures between 1300° C. and 1500° C. in N2 atmospheres leads to a continuous Si3N4 coating. The chemical stability and compatibility between Si3N4 and molten silicon enables its application in silicon metallurgy, in manufacturing crucibles for silicon fusion or for housing said molten silicon, in manufacturing pipes and chutes for its transport or in manufacturing different components for its subsequent purification.

Abstract: The invention is directed to methods to distinguish among different protein conformers of the same protein such as proteins which form amyloid deposits. Using the methods of the invention, one or more protein conformers in a sample can be detected, differentiated, and quantitated. An example of a protein which is known to exist in at least two conformations is the normal prion protein (PrPC) and its infectious isoform (PrPSc). The invention provides means to distinguish PrPC from PrPSc and allows quantitation of each individually, even when the conformers are present together in a mixture. Thus, the methods of the invention can provide important tools for human and animal health.

Abstract: Application of nanoparticles based on hydrophilic polymers as pharmaceutical forms for the administration of active macromolecules. The nanoparticles (having a nanometric size and a hydrophilic character), also called nanospheres or latex, are colloidal systems comprised of the combination of hydrophilic polymers and an active ingredient having a high molecular weight (active macromolecule, molecular weight higher than 1000 daltons). The hydrophilic polymers are the chitosan (an aminopolysaccharide) or its derivatives and polyoxyethylene or its derivatives. The association of the active macromolecule to said nanoparticles takes place in an aqueous phase without having to use organic solvents or auxiliary toxic substances. The active ingredient charge capacity of the nanoparticles is extremely high and additionally said charge is released in a controlled and time extended way. Additionally, said nanoparticles have a positive surface electric charge whose intensity may vary in relation to its composition.

Abstract: Application of nanoparticles based on hydrophilic polymers as pharmaceutical forms for the administration of active macromolecules. The nanoparticles (having a nanometric size and a hydrophilic character), also called nanospheres or latex, are colloidal systems comprised of the combination of hydrophilic polymers and an active ingredient having a high molecular weight (active macromolecule, molecular weight higher than 1000 daltons). The hydrophilic polymers are the chitosan (an aminopolysaccharide) or its derivatives and polyoxyethylene or its derivatives. The association of the active macromolecule to said nanoparticles takes place in an aqueous phase without having to use organic solvents or auxiliary toxic substances. The active ingredient charge capacity of the nanoparticles is extremely high and additionally said charge is released in a controlled and time extended way. Additionally, said nanoparticles have a positive surface electric charge whose intensity may vary in relation to its composition.

Abstract: Stabilization of colloidal systems through the formation of lipid-polyssacharide complexes. Development of a procedure for the preparation of colloidal systems involving a combination of two ingredients: a water soluble and positively charged polyssacharide and a negatively charged phospholipid. Colloidal systems (submicron emulsions and polymeric nanoparticles and nanocapsules) are stabilized through the formation, at the interface, of an ionic complex: aminopolyssachride-phospholipid. These colloidal systems are characterized by their positive charge and their improved stability. Furthermore, they can be freeze-dried, stored in a dry state and hydrated when required. They can be interesting systems for the administration of drugs by the oral, transdermal, ocular, nasal and vaginal routes of administration. In addition, they can be of interest for cosmetic use.

Abstract: A cell culture plate with a system for lateral diffusion of molecules across a barrier membrane (FIG. 1), comprising a base consisting of two or more flat-bottomed open-topped wells, denominated the reservoir wells, each containing one or more wells of smaller size (diffusion wells), likewise open-topped and sharing the same flat base, characterized in that each of the diffusion wells communicates with the larger reservoir well which houses it via one or several slits located in the lateral wall(s) of the diffusion well(s), and in that each slit is covered by a semipermeable membrane that permits the passage of soluble substances while retaining insoluble particles and cells; and a removable lid. The cells deposited in the diffusion well(s) may interchange their metabolic products with the corresponding reservoir well containing culture medium or other cells.