The invention relates to a coating composition, to a formulation comprising said coating composition, to methods of coating surfaces with the coating composition, and to articles coated with the coating composition. The coating composition is based on a complex of polyelectrolytes and oppositely charged surfactants. The surfactants contain fluorine bonded covalently to carbon atoms. The coating material imparts oleophobic and/or hydrophobic properties to various surfaces. The degree of hydrophobicity and other properties such as, for instance, gas or moisture permeation can be adjusted over a wide range. Through the use of additives, the coating can be executed as a permanent or temporary coating. The readily variable profile of properties, the uncomplicated application, and the low coat thickness result in a wide scope for application as, for example, an antisoiling, antigraffiti or antiadhesion coating.

The invention relates to a coating composition, to a formulation comprising said coating composition, to methods of coating surfaces with the coating composition, and to articles coated with the coating composition. The coating composition is based on a complex of polyelectrolytes and oppositely charged surfactants. The surfactants contain fluorine bonded covalently to carbon atoms. The coating material imparts oleophobic and/or hydrophobic properties to various surfaces. The degree of hydrophobicity and other properties such as, for instance, gas or moisture permeation can be adjusted over a wide range. Through the use of additives, the coating can be executed an a permanent or temporary coating. The readily variable profile of properties, the uncomplicated application, and the low coat thickness result in a wide scope for application as, for example, an antisoiling, antigraffiti or antiadhesion coating.
In the field of coating techniques, there exists a virtually innumerable number of different coating materials, each for very specific applications. In some cases a combination of polyelectrolytes and surfactants has been described.
DE 42 20 975 A1 describes oleophobic and/or permanent hydrophobic finishing for polymeric surfaces with a thin film. The film is formed from at least one layer of a water-soluble polycation and/or of a cationic synthetic resain. To further improve the oleophobic and/or permanently hydrophobic properties, the film may further comprise a long-chain surfactant or an alkyl-substituted polyanion. In the process described, the surface is first treated with a polycation solution and then treated, if desired, with an alkyl-substituted polyanion as second component or with a long-chain surfactant. Therefore, at least two different operations are required for coating. Furthermore, a prerequisite for application of the process is that the surface to be coated possesses a negative zeta potential.
This layer-by-layer construction by adsorption from aqueous solution has already been used for many years for scientific purposes and is described in a review by Decher (Science 277 (1997), 1232-1237).
International Patent Application Wo 96/11981 describes a fluorocarbon-containing additive which is applied subsequently to painted substrates and protects them against soiling or makes them easier to clean. These additives are based on discrete oligomers comprising a polyfunctional oligomeric core to which fluorinated alkyl chains are bonded covalently. The dirt repellency feature is achieved through the fluorinated alkyl chains, while adhesion to the paint is induced by the functionalized core. This type of protection by means of additives is strongly limited to well-defined, i.e. dust-free, painted surfaces. Furthermore, reaction times of from 6 hours to two weeks are necessary for preparing the fluorinated additives.
U.S. Pat. No. 5,330,788 describes a temporary coating for surfaces, developed in particular for protecting automobiles in transit. The coating is based on a film-forming acrylic acid polymer, a nonionic acetylenically unsaturated surfactant, if desired, a phosphate ester surfactant, and a base for neutralization. The coating material can be removed rapidly in contact with a special alkaline aqueous medium, which is likewise described in the patent. Extremely disadvantageous are, apparently, the long drying times for the coating, which are stated as being xe2x80x9covernightxe2x80x9d or 24 hours. Since the principal component, the polyacrylic acid, is a polyelectrolyte which finds application as a super-absorbent (used, for example, in diapers and to improve the water retention capacity of arid soils), it cannot be assumed that these drying times, which are unreasonably long from an economic standpoint, might be substantially reduced.
U.S. Pat. No. 5,387,434 describes an antigraffiti composition whose protective action derives from sodium silicate. Since this is soluble in water, the interface between substrate and environment must be made hydrophobic. This is achieved by means of latex, silicones, or waxes. Particularly suitable are microcrystalline wax emulsions which are stabilized by sodium lignin-sulfonate. Graffiti removal requires high-pressure steam jets with a pressure of 100 psi, and temperatures of up to 90xc2x0 C. Consequently, this process is suitable only for very specific substrates which permit these conditions without damage. No statement concerning the drying time of the coating can be found in the patent. However, it must be assumed that the crosslinking of the silicate requires several hours to days. Furthermore, it is likely that drying, which is retarded as a result of the added wax, will likewise take at least one day under dry conditions.
DE 36 30 520 C1 describes a process for protecting applications of color to surfaces of natural and synthetic stone. The process consists of two steps: first, an inorganic impregnation is applied, which is not specified in any great detail. This is followed by the application of a color-accepting, detachable, wax-like coating which can be removed by means of high-pressure hot water. Owing to the fact that it necessitates at least two different operations, this process is very time-consuming. In the case of typical inorganic impregnations, from at least one to three days are necessary given dry weather. Furthermore, this process is applicable only to a very limited number of specific substrates.
European Patent Application EP 0 695 772 A1 describes a class of fluorine-containing polyethers which are applied to masonry where they crosslink and form an impermeable antigraffiti film. The synthesis of the crosslinkable substances, however, is time-consuming and costly, and the raw material applied requires a drying time of 48 hours on the masonry in order to crosslink sufficiently. Furthermore, the field of use is limited to the coating of masonry.
Available on the market there is a surface protection is system from the company PSS (Protective Surface System) which is based or a polysaccharide mixture. According to an examination certificate from the German Federal Institute of Materials Research (Report No. 3.14.3441-91), effective protection against graffiti with the system PSS 20 requires three coats with drying times of from 24 to 72 hours in each case. Thus from 3 to 9 days are necessary for the application of the protective coat.
All of the abovementioned coating processes are characterized by a closely limited field of use and, in some cases, by drying times of several days for the protective coats.
DE-A-44 28 641 describes mesomorphic complexes comprising anionic polyelectrolytes, cationic polyelectrolytes and/or polyampholytes, and cationic, anionic, nonionic and/or amphoteric surfactants. As a consequence of the mesomorphic structure, generally improved material properties, such as increased mechanical strength, for example, are expected. The materials constructed of these amorphous or mesomorphic polyelectrolytes, such as films or membranes, include as an essential component surfactants having a hydrocarbon framework. Coatings with low-energy surfaces, however, cannot be produced using the fluorine-free complexes described therein.
Antonietti et al. (Adv. Mater. 8 (1996), 41-45) and Lochhaas et al. (Polyelectrolyte-surfactant complexes with fluorinated surfactants: A new type of material for coatings (3rd conference in the series: High Performance Coating Materials, Fluorine in Coatings II, Feb. 24-26, 1997, Munich, Germany) describe complexes comprising cationic polyelectrolytes and anionic fluorinated surfactants. Cationic polyelectrolyte components disclosed include polyacrylic acid, polymethacrylic acid, and poly(diallyldimethylammonium chloride). On contact with moisture these complexes have a very high propensity to absorb water; they swell rapidly and in doing so become soft to gelatinous. This leads to a considerable deterioration in the mechanical properties, so rendering them unsuitable for practical applications as coating material.
It is an object of the present invention to develop a coating material in which at least some of the disadvantages of the prior art are eliminated. In particular, the coating material should be applicable by simple methods to any desired surfaces and should produce a low-energy surface even when small amounts are used. Furthermore, the coating material should be highly stable to a water-containing environment.
This object is achieved through the provision of a coating material based on a complex which comprises at least one nonhygroscopic polyelectrolyte and at least one oppositely charged, fluorinated surfactant.
The coating material of the invention surprisingly allows an accumulation of fluorinated organic groupsxe2x80x94alkyl chains, for examplexe2x80x94at its surface, so that the oleophobicxe2x80x94or hydrophobicxe2x80x94properties of the coated surface are improved. Through the combination of nonhygroscopic polyelectrolyte and fluorinated ionic surfactant a highly ordered, mechanically stable complex is formed which both adheres to almost any substrate and forms a highly fluorinate, low-energy surface. Sufficient adhesion and the formation of low-energy surfaces are inherently contradictory principles, which can surprisingly be unified in one material by the novel combination of nonhygroscopic polyelectrolyte and fluoro surfactant.
The complex of the invention may comprise a cationic polyelectrolyte and an anionic surfactant, or an anionic polyelectrolyte and a cationic surfactant. It is preferred to use cationic polyelectrolytes and anionic surfactants.
The stoichiometry of the complex, based on the charges of polyelectrolyte and surfactant, is preferably such that there is essentially charge compensation in respect of the polyelectrolyte on the one side and surfactant on the other. Advantageously, therefore, the stoichiometry of the complex, based on the charges of polyelectrolyte and surfactant, is from about 1.5:1 to 1:1.5, with particular preference from about 1.3:1 to 1:1.3, and most preferably about 1:1.
In addition, the complex preferably has a mesomorphic structure, as may be determined by measuring the small-angle X-ray scattering. It is further preferable that the complexes of the invention possess no crystallinity, as can be determined by measuring the wide-angle X-ray scattering.
The complexes of the invention are obtainable by adding an aqueous solution of the polyelectrolyte to an aqueous solution of the fluorinated surfactant and isolating the resultant precipitate, which forms spontaneously. Both when adding a cationic polyelectrolyte in aqueous solution to an aqueous solution of the anionic fluorinated surfactant, and when adding an anionic polyelectrolyte to a cationic fluorinated surfactant, the complex preferred in accordance with the invention is formed with a stoichiometry of about 1:1, based on the charges of polyelectrolyte and surfactant. Moreover, the formation of this preferred complex is favored by working at an elevated temperature of at least 40xc2x0 C., with particular preference from 50 to 90xc2x0 C. In the converse casexe2x80x94the addition of a surfactant solution to the polyelectrolyte solutionxe2x80x94it is not unusual for there to be considerable deviations from the preferred stoichiometry, which in certain instances may result in an unwanted sharp increase in the hygroscopicity.
The resultant novel supramolecular polymer complex precipitate may be dissolved in polar organic solvents. This is surprising, since polymeric materials having a high fluorine content are usually of extremely low solubility or else completely insoluble. When this complex solution is applied to a surface and the solvent is evaporated, a thin, usually transparent film of the complex material is formed on the surface. It has been found that the surface energy after coating with the complex materials of the invention was lower in all cases than prior to coating. A consequence of this is reduced adhesion of impurities on the surface. This effect was found on a large number of different surfaces, examples being glass, stone, wood, paper, metal, plastics, natural materials such as cotton fibers, for instance, and on painted surfaces as well; in other words, the effect is independent of the type of substrate and is accompanied by good coating adhesion.
A further surprising finding has been that the complexes of the invention are readily emulsifiable with nonionic surfactants, preferably nonionic fluorinated surfactants. In this way, the complexes may also be processed with an aqueous carrier material and hence applied in a particularly environment-friendly way.
The present invention therefore further provides a complex comprising polyelectrolyte and ionic fluorinated surfactant, said complex further comprising at least one nonionic surfactant, preferably a nonionic fluorinated surfactant. The proportion of the nonionic surfactant may be varied over a wide range depending on the nature of the application and may, for example, be up to 200% (w/w) based on the weight of the complex.
By varying the proportion of emulsifier, i.e., nonionic surfactant, it is possible to control the permanence of the coating. For the application of permanent coatings, the proportion of the nonionic surfactant should be up to not more than 20%, preferably up to 10% and, with particular preference, up to 5%, based in each case on the weight of the complex. For temporary coatings, proportions of the nonionic surfactant of from 20 to 200% and, in particular, from 50 to 80%, based on the weight of the complex, are preferred. With a high proportion of emulsifier, the coating may be washed off using customary domestic surfactant solutions. This is of great interest in particular for the temporary intransit coating of, say, automobiles.
It has been found, furthermore, that the gas permeability and water absorption capacity may both be varied widely by means of appropriate combinations of polyelectrolyte and surfactant. This is of great importance since with many coatings, such as antigraffiti coats, for example, it is necessary not to seal the surfaces, in order to prevent the formation of mold and fungus.
The complex compounds of the invention can be prepared easily and quickly, from aqueous solution, for example.
They can be processed both as solutions and as aqueous emulsions to form thin films on any desired surfaces. For very low expenditure of material, these films greatly reduce the surface energy, and so can be used almost universally wherever surfaces having Teflon-like properties are required or desired.
Owing to the low coat thicknesses required to reduce the surface energy, the ease of preparation, and the short drying times, the coating is very cost-effective per unit area. The drying times of the films may be reduced to a few minutes or hours. The coating permits elastic flexing of the coated articles. The film coatings are preferably transparent and are impossible or difficult to perceive under light which is incident, for example, at an oblique angle. The breathability, i.e., the permeability to gases and water vapor, and also water absorption, can be adjusted within wide limits.
The coating of surfaces with the polyelectrolyte-fluoro surfactant complexes of the invention is always judicious when the aim is to reduce natural or artificial soiling. For this purpose the surface is coated with a thin film. Irrespective of the nature of the surface, the surface energy is reduced as a result of the coating. The coating permits elastic flexing of the coated article without chipping or flaking. The films possess long-term stability at temperatures of up to 100xc2x0 C. Depending on the complex used, temperature stabilities of from 120 up to 230xc2x0 C. may even be attained.
With the exception of highly hygroscopic polyelectrolytes such as polyacrylic acid, polymethacrylic acid and poly(diallyldimethylammonium chloride), and salts thereof, any desired combinations of polyelectrolytes and fluorinated ionic surfactants are suitable. When using nonhygroscopic polyelectrolytes of the invention, the complexes obtained have a low water absorption of preferably not more than 5% (w/w), with particular preference not more than 4.5% (w/w), and most preferably not more than 4% (w/w), based on the weight of the complex, at 20xc2x0 C. and 100% relative atmospheric humidity.
Polyelectrolytes are substances containing two or more positive or negative charge carriers. A preferred class of cationic polyelectrolytes are polymers containing preferably at least 20% of one or more of the following monomer units, with the proviso that the resultant polyelectrolyte is a nonhygroscopic polyelectrolyte within the meaning of the present invention:
ethylenically unsaturated monomers which carry positively charged nitrogen groups, e.g., quaternary ammonium groups or N-substituted heteroaromatic groups, said monomers being in the form either of salts, as obtained by reacting basic amino functions with mineral acids, e.g., hydrochloric acid, sulfuric acid or nitric acid, or in quaternized form (e.g., by reaction with dialkyl sulfates such as dimethyl sulfate, diethyl sulfate, etc., alkyl chlorides such as methyl chloride, ethyl chloride, etc., or benzyl chloride), examples being dimethylaminoethyl acrylate hydrochloride, diallyldimethylammonium chloride, dimethylaminoethyl acrylate methosulface, di-methylaminopropylmethacrylamide methochloride, di-methylaminopropylmethacrylamide methosulfate, vinylpyridinium salts, and 1-vinylimidazolium salts.
In addition to the cationic monomer units, the cationic polyelectrolyte may if desired contain one or more nonionic monomers in an amount, for example, of up to 80 mol %. The presence of nonionic monomers is necessary in some instances, as in the case of poly(diallyldimethylammonium chloride), for example, in order to reduce the hygroscopicity.
Examples of suitable nonionic monomers are C1 to C20 alkyl esters and hydroxyalkyl esters, and especially amides and N-substituted amides, of monoethylenically unsaturated C3 to C10 monocarboxylic acids or C4 to C8 dicarboxylic acids, e.g., acrylamide, methacrylamide, N-alkylacrylamides or N,N-dialkylacrylamides having in each case 1 to 18 carbon atoms in the alkyl group, such as N-methylacrylamide, N,N-dimethylacrylamide, N-tert-butylacrylamide or N-octadecylacrylamide, N-methylhexylmaleimide, N-decylmaleimide, dimethylaminopropylmethacrylamide or acrylamidoglycolic acid, and also alkylaminoalkyl (meth)acrylates, examples being di-methylaminoethyl acrylate, dimethylaminoethyl methacrylate, ethylaminoechyl acrylate, diethylaminoethyl methacrylate, dimethylaminopropyl acrylate and di-methylaminopropyl methacrylate, and also vinyl esters, examples being vinyl formate, vinyl acetate and vinyl propionate, which after polymerization may also be present in hydrolyzed form, and also N-vinyl compounds, examples being N-vinylpyrrolidone, N-vinylcaprolactam, N-vinylformamide, N-vinyl-N-methylformamide, 1-vinylimidazole, 1vinyl-2-methylimidazole, and N-methylvinylacetamide.
An example of cationic polyelectrolytes composed of cationic and nonionic monomers is as follows:
copolymers of dialkenyldialkylanmonium salts, e.g., diallyldimethylammonium chloride, with nonionic monomers, e.g., N-methylvinylacetamide, in which the proportion of nonionic monomer is preferably at least 20 mol %.
Further preferred classes of cationic polyelectrolytes are the following:
polyethyleneimines and alkyl-substituted polyethyleneimines, e.g., poly(ethyleneimine-co-N-docosylethylimine);
ionenes, i.e., polymers having two or more quaternary ammonium groups and formed, for example, by reacting di-tertiary amines with xcex1,xcfx89-dihaloalkenes, e.g., 6,3-ionene, and
polysaccharides containing cationic groups, especially xcex2-glycosidically linked polysaccharidea, such as chitosan, for instance.
To prepare the complexes of the invention, said cationic polyelectrolytes can be used in base form, partially neutralized or tully neutralized.
In addition, anionic polyelectrolytes are also suitable for the method of the invention. A preferred class of such anionic polyelectrolytes are polymers containing preferably at least 20 mol % of one or more of the following monomer units, with the proviso that the resultant polyelectrolyte is a nonhygroscopic polyelectrolyte within the meaning of the present invention:
ethylenically unsaturated carboxylic acids and their salts and derivatives, e.g., C3 to c10 mono-carboxylic acids, their alkali metal and/or ammonium salts, examples being dimethylacrylic acid or ethylacrylic acid, C4 to C8 dicarboxylic acids, their monoesters, anhydrides, alkali metal salts and/or ammonium salts, e.g., maleic acid, fumaric acid, itaconic acid, mesaconic acid, methylenemalonic acid, citraconic acid, maleic anhydride, itaconic anhydride or methylmalonic anhydride;
ethylenically unsaturated monomers containing sulfonic acid groups, examples being allylsulfonic acid, styrenesulfonic acid, vinylsulfonic acid, 3-sulfopropyl acrylate, and 3-sulfopropyl methacrylate,
monoethylenically unsaturated monomers containing phosphinic, phosphonic or phosphoric acid groups, e.g., vinylphosphonic acid, allylphosphonic acid, or acrylamidomethylpropanephosphonic acid.
If desired, these anionic polymers may contain one or more of the abovementioned nonionic monomers in a proportion, for example, of up to 80 mol %. The use of copolymers comprising anionic and nonionic monomers is preferred for some of the anionic monomers in order to reduce the hygroscopicity.
A further preferred class of anionic polyelectrolytes are polyaaccharides containing anionic groups.
The anionic polyelectrolytes can be used in the acid form, partially neutralized or fully neutralized.
Ionic fluorinated surfactants are substances which contain at least one fluorine atom attached to a carbon atom, preferably at least one xe2x80x94CF2 group and/or CF3 group, and at least one charge carrier.
Anionic fluorinated surfactants comprise at least one fluorine-containing hydrophobic group and at least one negative charge carrier. Examples of such compounds are fluorinated carboxylic acids and their salts with organic or inorganic cations, fluorinated sulfonic acids and their salts with organic or inorganic cations, fluorinated organic sulfuric acids and their salts with organic or inorganic cations, and fluorinated phosphinic, phosphonic or organ-phosphoric acids and their salts with organic or inorganic cations.
Among these classes of compound, preference is given to the following;
perfluorocarboxylic acids and their preferably water-soluble salts, such as perfluoroalkanoic acids, e.g., in particular, perfluoroalkanoic acids of the formula CF3(CF2)nxe2x80x94COOH, where n is preferablyxe2x89xa77;
partially fluorinated carboxylic acids and carboxylic acid salts, such as partially fluorinated alkanoic acids, partially fluorinated alkenoic acids, perfluoroalkoxyalkanoic acids, perfluoroalkylethyleneoxyalkanoic acids, perfluoroalkoxybenzoic acids, and partially fluorinated carboxylic acids containing sulfide, sulfone, carboxamide, hydroxyl, oxo and/or ether groups, and salts of such acids; e.g., lithium 3-[(1H, 1H, 2H, 2H-fluoroalkyl) thio]propionate, Zonyl FSA(copyright), Du Pont;
perfluorosulfonic acids and their preferably water-soluble salts, such as perfluoroalkanesulfonic acids of the formula CF3(CF2)mxe2x80x94SO3H, where mxe2x89xa71;
partially fluorinated sulfonic acids and their preferably water-soluble salts, such as partially fluorinated alkanesulfonic acids, e.g., perfluoroalkylethaniesulfonic acids, perfluoropropylalkanesulfonic acids, partially fluorinated arylsulfonic acids, e.g., perfluoroalkylbenzenesulfonic acids, perfluoroalkoxybenzenesulfonic acids, perfluoroacylbenzenesulfonic acids, partially fluorinated alkenesulfonic acids, and also partially fluorinated sulfonic acids containing sulfide, carboxamide, hydroxyl, oxo and/or ether groups, fluorinated sulfo esters, e.g., sulfosuccinic esters, perfluoroalkyl sulfopropionates, perfluoroalkyl sulfobutyrates and salts thereof; e.g. perfluoroalkylethylsulfonic acid ammonium salt, Zonyl TBS(copyright) Du Pont; sodium [succinic acid diperfluoroalkylethyl diester 2-sultonate], Fluowet SB(copyright), Hoechst;
fluorinated organic sulfuric acids and their salts, such as perfluoroalkylated methyl sulfates, fluorinated sulfatopoly(oxyethylene), perfluoropropoxylated sulfates, and salts thereof;
fluorinated phosphinic and phosphonic acids and their preferably water-soluble salts, e.g., Fluowet PL80(copyright), Hoechst;
fluorinated organic phosphoric acids and their salts, such as perfluoroalkylethanephosphoric acids, mono- and bis(fluoroalkyl)phosphoric acids, perfluoroalkylphosphoric acids, fluorinated alkene-phosphoric acids, fluorinated phosphate alkyl esters, e.g., phosphoric acid perfluoroalkyl ester ammonium salt, Zonyl FSE(copyright) and Zonyl FSP(copyright), Du Pont.
Cationic surfactants are also suitable for the method of the invention. Preferred classes of such compounds are as follows:
fluorinated amines and ammonium salts, such as fluoroalkylammonium salts, which may if desired contain carboxamide, sulfonamide, sulfide, ester and/or hydroxyl groups, or heterocyclic nitrogen compounds, e.g., perfluoroalkylethyltrialkylammonium methosulfate, Hoe-L-3658-1, Hoechst.
Examples of nonionic surfactants, especially fluorinated surfactants, are compounds containing one or more nonionic hydrophilic groups and one or more fluorine-containing hydrophobic groups. Preferred examples of such compounds are fluorinated alcohols, examples being those containing one or more oxyethylene or oxypropylene groups, fluorinated polyethers, fluorinated polyhydric alcohols, oxyalkylated perfluorophenols, perfluoroalkyl-2-ethanethiol derivatives, and also compounds containing carboxamide or sulfonamide groups.
Further judicious ionic fluorinated surfactants that can be used to prepare the complexes, and nonionic fluorinated surfactants that can be used as emulsifiers to prepare aqueous emulsions, are described in the book by Erik Kissa (Fluorinated Surfactants, Surfactant Science Series Vol. 50, Marcel Dekker, Inc., New York, 1994)
Complexes of the invention further comprising a nonionic surfactant are preferably prepared by adding the particular desired proportion of nonionic surfactant to a complex comprising polyelectrolyte and fluorinated ionic surfactant.
The present invention further provides a formulation comprising a complex of the invention, comprising polyelectrolyte and ionic fluorinated surfactant, in solution in a polar organic solvent. Said formulation comprises the complex preferably in a proportion of from 0.1 to 30% (w/w), with particular preference from 0.5 to 10% (w/w), and most preferably from 1 to 5% (w/w), based on the weight of the formulation. The solvent is preferably a volatile and largely nontoxic organic solvent, examples being methanol, ethanol, acetone, ethyl acetate, and mixtures thereof.
The present invention additionally provides a formulation comprising a complex of the invention, comprising polyelectrolyte and ionic fluorinated surfactant, and preferably nonionic surfactant, in emulsion in an aqueous solvent. The complex is present preferably in a proportion of from 0.1 to 30% (w/w), with particular preference from 0.5 to 10% (w/w), and most preferably from 1 to 5% (w/w), based on the weight of the emulsion. The emulsion of the invention is, surprisingly, stable at 20xc2x0 C. for at least two weeks.
The emulsion of the invention is obtainable by adding the particular desired amount of a nonionic surfactant to a complex comprising polyelectrolyte and ionic fluorinated surfactant, converting this mixture into a substantially homogeneous mixture, and diluting that mixture with water, preferably in portions, so as to obtain an aqueous emulsion.
The complexes of the invention, and the complex-containing compositions, might be used to coat surfaces. Exemplary applications are as antisoiling compositions, especially antigraffiti compositions, as protective compositions for vehicles in transit, e.g., automobiles or machines, as anti-icing protection, especially for civilian or military air travel, as marine antifouling coatings, as release agents and lubricants, in the production, for example, of tiles, bricks or construction shuttering, as compositions for impregnating textiles, e.g., cotton with GoreTex properties, and carpeting, and as a membrane, e.g., as a gas separation membrane.
The invention further provides a method of coating a surface, in which a formulation of the invention is applied to said surface and allowed to dry. This coating operation mayxe2x80x94where necessaryxe2x80x94also be repeated, using different complexes in each case if desired. Application may be made from an organic solution or from an aqueous emulsion. The drying time for organic solutions is preferably not more than 1 hour, with particular preference from a few seconds to a few minutes. The drying time for aqueous emulsions is preferably not more than 6 hours, with particular preference not more than 3 hours. The coating composition may be applied discontinuously or continuously by means of customary techniques such as, for instance, spraying, flow coating, dipping, or mechanical application, e.g., roller application. The thickness of the coating is preferably from 0.1 xcexcm to 1 mm, with particular preference from 1 to 10 xcexcm.
The present invention provides, further still, an article coated at least in part with a coating comprising a complex of the invention comprising polyelectrolyte and fluorinated ionic surfactant. The coated surface preferably has an energy of less than 20 mN/m. The coating is preferably substantially transparent, ie., transparent to visible light. Further, the coating is preferably stable to contact with a water-containing atmosphere; that is, it does not tend toward significant swelling. Furthermore, the coating is preferably stable up to a temperature of 100xc2x0 C. Depending on what is required, the coating may be permanent or temporary, permeable to air and/or moisture, or impermeable to air and/or moisture.
One advantage of the coatings of the invention is that at their surface facing the surroundings they have a heightened fluorine content as compared with the interior of the coating, a fact which contributes to reducing the surface energy. Furthermore, they possess preferably a contact angle hysteresis of between 5xc2x0 and 20xc2x0. In addition, the coatings of the invention exhibit low water absorption, preferably not more than 5% (w/w), with particular preference not more than 4.5% (w/w), and most preferably not more than 4% (w/w), based on the weight of the coating, at 20xc2x0 C. and 100% relative atmospheric humidity.


A system is disclosed for providing service to a vehicle (1) positioned at a service site (2) and billing a person or company for the service provided, wherein the vehicle (1) is provided with a vehicle processing unit (10) which includes a receiver-transmitter connected to a vehicle antenna (12) and with element for manually activating the vehicle processing unit, and wherein the service site (2) comprises element for providing service (3), a site processing unit (20) which includes a receiver-transmitter connected to a site antenna (22), which site processing unit includes element for registering the transaction and means for billing the person or company for the service provided, which system further comprises means for automatically correlating the act of servicing the vehicle with the vehicle (1), which element may comprise a passive tag (30) located at the element for providing service (5), element for energizing the passive tag located on the vehicle (1) and a secondary antenna (33) on the vehicle (1) connected to the vehicle processing unit (10).

European patent No. 461 888 discloses automatically identifying a vehicle approaching a service site, providing service to the vehicle at the service site, and billing a person or company for the service provided. The known system relies on determining electronically whether an approaching vehicle is stopping for service and on identifying electronically the approaching vehicle as it enters into a service site. To this end the vehicle is provided with a passive tag which is activated by a signal from a site antenna that is always energized. When the service has been provided the transaction is registered and the costs associated with the service are billed.
In the known system, every approaching vehicle is identified, even when the driver passes through the service site in order to visit a shop or a toilet that is present on the premises. Furthermore, special precautions have to be taken to prevent any other nearby service site from identifying the vehicle after it has been identified by the service site where it stops.
The present invention provides a system and a method for providing service to a vehicle positioned at a service site wherein the driver manually starts the process of identifying the vehicle, and wherein in addition the transaction itself is monitored as well.


An object of the present invention is to provide a gradual disintegration-type, sustained-release pharmaceutical solid preparation whose pharmacologically active substance release behavior is controlled. The solid pharmaceutical preparation of the present invention is a matrix-type preparation containing: (a) a pharmacologically active substance; (b) calcium polycarbophil; and (c) a specific sugar and/or sugar alcohol.

There have been many attempts in the pharmaceutical industry to control drug release and maintain drug concentration in the blood at an appropriate level for a long period of time. In order to maintain drug concentration in the blood at an appropriate level for a long period of time, a pharmaceutical advancement (release control) to maintain drug absorption for a long time is necessary. Such release-controlled pharmaceutical preparations are referred to as "sustained-release preparations".
Sustained-release preparations are defined as pharmaceutical preparations in which the release rate, release time, and release location of the pharmaceutically active ingredient are controlled with the purpose of reducing the frequency of administration, or decreasing side effects. Immediate-release preparations are defined as pharmaceutical preparations whose pharmacologically active substance release is not particularly controlled. For example, with respect to oral preparations, water-insoluble matrix-type, hydrogel matrix-type, film coating-type, osmotic pump-type, or like sustained-release preparations are widely known.
Immediate-release preparations and sustained-release preparations can be classified according to the length of disintegration time of the pharmaceutical preparation, instead of whether the release is controlled or not. More specifically, immediate-release preparations disintegrate in a short time and immediately release a pharmacologically active substance. Sustained-release preparations disintegrate over a long period of time and gradually release a pharmacologically active substance. To control the disintegration rate of a pharmaceutical preparation, the incorporation of a disintegrant into the pharmaceutical preparation is important. To obtain a desired disintegration rate, the selection of an optimal disintegrant is also important. Disintegration induced by disintegrants can be roughly classified into two types: swelling and capillary action (wicking). Swelling-type disintegrants disintegrate pharmaceutical preparations with their excellent water absorption and swelling capabilities. In contrast, wicking-type disintegrants cause water to quickly penetrate into pores in the pharmaceutical preparation to break the bonds between particles, thus dispersing the particles.
However, each type of disintegrants, i.e., swelling-type disintegrants and wicking-type disintegrants, has disadvantages. Since even a small amount of swelling-type disintegrant is highly effective in quickly causing the internal disintegration of pharmaceutical preparations, disintegrants of this type are unsuitable for prolonged disintegration control, i.e., sustained release. Wicking-type disintegrants have a low swelling ability and are thus less likely to cause internal disintegration of pharmaceutical preparations. However, even a slight decrease or increase in the amount of wicking-type disintegrant may result in insufficient disintegration or disintegration behavior similar to that of immediate-release pharmaceutical preparations. That is, precise adjustment of the amount of wicking-type disintegrant is difficult.
It is thus extremely difficult to achieve sustained release by controlling disintegration through mere selection of a disintegrant and mere adjustment of the amount of disintegrant used.


A method is provided for synchronizing the playback of a digital audio broadcast on a plurality of network output devices by inserting an audio waveform sample in an audio stream of the digital audio broadcast. The method includes the steps of outputting a first unique signal as part of an audio signal which has unique identifying characteristics and is regularly occurring, outputting a second unique signal so that the time between the first and second unique signals must be significantly greater than the latency between sending and receiving devices, and coordinating play of audio by an audio waveform sample assuring the simultaneous output of the audio signal from multiple devices. An algorithm in hardware, software, or a combination of the two identifies the audio waveform sample in the audio stream. The digital audio broadcast from multiple receivers does not present to a listener any audible delay or echo effect.

In order to achieve a depth and richness of sound, two or more audio devices are used to provide a surround sound effect to the listener. These audio devices may be cabled to a controller device which provides the audio data to them. A bus may be used to supply this data. Alternatively, the different devices may communicate with each other through wireless communication, such as through an RF or infrared port.
In a system in which one computer or device broadcasts a single digital audio stream that is then simultaneously received by more than one receiving device, the different receiving devices will often play their audio slightly out of sync with each other, due to differing latencies in receiving and processing the digital audio stream. This produces an echo or delay effect which causes a listener to receive the same audio at slightly different times from the multiple devices. The listener's enjoyment is thereby impaired.
A method and apparatus for synchronizing the playback of audio from several devices is needed.

This patent is subject to a terminal disclaimer.

Method of synchronizing the playback of a digital audio broadcast using an audio waveform sample


A card reader may include a conveying passage; a magnetic head structured to abut with a magnetic stripe on the card; a head moving mechanism structured to move the magnetic head in a widthwise direction of the conveying passage between an abutting position and a retreated position; an IC contact block having a plurality of IC contact springs to contact a plurality of external connection terminals of an IC chip formed on the card; and a contact block moving mechanism structured to move the IC contact block between a contact position retreated position. The conveying passage may be formed with an opening part through which the magnetic head is passed. The magnetic head may be located at the head abutting position and is abutted with the one face of the card at a time when the IC contact springs and the external connection terminals are contacted with each other.

Conventionally, a magnetic head moving type magnetic stripe reading/writing device has been known where reading of magnetic data from a magnetic stripe formed on a magnetic medium and writing of magnetic data to the magnetic stripe are performed (see, for example, Patent Literature 1). A magnetic medium which is processed in the magnetic stripe reading/writing device described in Patent Literature 1 is formed with a magnetic stripe in a direction perpendicular to a conveying direction of the magnetic medium. The magnetic stripe reading/writing device includes a slide mechanism which moves the magnetic head in a direction where the magnetic stripe is formed and conveying rollers for conveying the magnetic medium in a direction perpendicular to the moving direction of the magnetic head. Further, in the magnetic stripe reading/writing device, an opening part for moving the magnetic head is formed in a conveying passage for a magnetic medium.
Further, conventionally, a card reader has been known where data communication is performed with a contact type IC card having a built-in IC chip (see, for example, Patent Literature 2). A surface of a contact type IC card is formed with external connection terminals of an IC chip. The card reader described in Patent Literature 2 includes an IC contact block having IC contact springs for contacting with the external connection terminals of the card.
Further, conventionally, a magnetic head moving type card processing device has been known where reading of magnetic data from a magnetic stripe formed on a card and writing of magnetic data to the magnetic stripe are performed (see, for example, Patent Literature 2). In the card processing device described in Patent Literature 2, a pad is provided for abutting a magnetic head with the magnetic stripe at a predetermined abutting pressure when reading and writing of magnetic data are to be performed. The pad is provided so as to face the magnetic head. Further, the pad is provided over the entire region of a moving range of the magnetic head in a moving direction of the magnetic head.
A shape of a card having a magnetic stripe is specified in the international standard and JIS standard and is formed in a substantially rectangular shape whose four corners are rounded. Further, in a card with a magnetic stripe in conformity with the international standard and JIS standard, the magnetic stripe is formed in a long and thin strip shape which is parallel to a longitudinal direction of the card formed in a substantially rectangular shape and is formed on a rear face of the card. Further, a position of the magnetic stripe in the short widthwise direction of the card is also specified in the international standard and JIS standard and the magnetic stripe is formed in a predetermined range with one end of the card in the short widthwise direction of the card as a reference.
Further, there is an embossing card which is formed with characters, digits or the like formed by embossing. In an embossed card in conformity with the international standard and JIS standard, an embossing area where embossing is performed is determined and a predetermined area with the other end in the short widthwise direction of the card is determined as the embossing area. Further, a predetermined area except both end sides in a longitudinal direction of the card is determined as the embossing area. Characters, digits or the like which are formed in the embossing area by embossing are protruded to a front face side of a card.


A method and apparatus for tracking a special service delivery by a carrier of a mail item created by an office worker. The method utilizes one or more special service indicators on the mail item to ensure that the office worker can obtain information about the status of the mail item by the simple placement of one of the special service stickers on the mail item.

Mail communication systems (for purposes herein such systems include postal services as well as private carrier services) are designed to provide for the delivery of physical mail items. These systems include mailers (senders of mail items), service providers (carriers and postal operators and their suppliers) and recipients. When a mailer sends a physical mail item (letter, flat, or parcel) he or she is typically interested in 1) knowing that the mail item has been delivered, 2) knowing the time of delivery and 3) in many cases having some (hopefully legally admissible) proof of delivery. Moreover, the mailer may also be interested in checking on the status of a yet to be delivered mail item particularly if there is some concern that the mail item may be lost. Traditional postal and carrier systems address this need by offering premium "track & trace" services. These traditional track and trace services assign a unique carrier generated number to each mail item which is used to track the mailpiece through the carrier distribution system. Confirmation of final delivery of the mail item is accomplished by either providing the sender with a physical document containing information about delivery or alternatively allowing the sender to access a web site of the service provider where the unique carrier generated number can be found if the mail item has been delivered. Additionally, inquiries regarding mail item tracking status are checked via the unique carrier assigned number.
One of the major problems of these traditional track and trace services is that the sender must go to the carrier's retail location to deliver the mail item personally in order to get the unique carrier generated number. Additionally, while some carriers have now introduced the ability to obtain a unique carrier generated number over the internet which can be applied to the mailpiece by the sender, this approach has the downside of requiring the sender to be connected to the carrier's website via the internet whenever use of the track and trace service is required. Furthermore, in the web-based system just described, the carrier loses control of ensuring that a particular unique carrier generated number was actually affixed to a specific mailpiece.
Each of the aforementioned United States Patent Applications address one solution to some of the problems set forth above by having the sender provide on a mail item a unique sender generated identifier consisting of a unique number and an electronic address such as an e-mail address of the sender. This identifier can then be used by the carrier service to provide information to the e-mail address about, for example, the delivery of the mail item. The problem with this solution is that it relies on the sender generated unique number for tracking the mailpiece. Carriers may consider this to be unacceptable since they would have to rely on the quality of the sender generated unique number for tracking mail items through their system.
In addition to the above, yet another problem exists in an office building environment where mail is generated by individual office workers and sent to a mailroom for final processing. That is, the function of the mail room is to collect mail items created by office workers, finish the mail items by applying postage thereon and submit the mail items to postal operators (or other carrier) for processing and delivery. Mail rooms are typically equipped with mailing machines, postage meters, scales and other equipment for mechanization of such finishing work. Conventional mailing machines are capable of automatic feeding, sealing and metering of mixed mail items. However, currently there is no effective way of processing value added services mail items (mail that is accounted for such as proof of deposit, receipt, or delivery—also referred to previously as premium service mail items) through a mailing machine. Thus, these premium service mail items have to be created and processed in essentially a manual way.
Accordingly, what is needed is a system and method that allows office workers to obtain track and trace and/or confirmation of special services delivery of a mail item in a more automated manner than the prior art systems.

Method and apparatus for tracking a special service delivery of a mail item created by an office worker


An image display system may include an image display device, and first and second attachments. The image display device may include a frame wearable on a user's face, a display unit, display controlling unit causing the display unit to display an image, and a joint portion provided on the frame, capable of having the first attachment mounted thereon, capable of having the second attachment mounted thereon, and capable of selectively having one of the first and second attachments mounted thereon when the image display device is used. The first attachment may include an engaging portion capable of engaging with a use's head and a first attaching portion that attaches the engaging portion to the joint portion. The second attachment may include a fixing portion fixable to headwear covering the user's head and a second attaching portion that attaches the fixing portion to the joint portion.

Japanese Patent Application Publication No. 2014-93050 (referred to as Patent Literature 1 hereinbelow) describes an image display device to be worn on a face of a user when used, for example. This image display device is provided with a frame wearable on a face of a user, a display unit configured to be arranged at positions facing right and left eyes of the user in a case where the frame is worn on the face of the user, and a display controlling unit configured to cause the display unit to display an image.


The present invention relates to a saturable nonwoven material comprising fluoropolymer floc and aramid floc, which can be used as a substrate for a liner for self-lubricating bearings and for other applications.

1. Field of the Invention
This invention relates to saturable nonwoven materials comprising fluoropolymer fibers and other additional wettable structural organic fibers. Such nonwovens may be used as a liner material for self-lubricating bearing surfaces, as a sealant, in filtration systems, as electrical insulation and in other applications.
2. Description of the Related Art
The use of a woven or knitted fabric as a liner material for self-lubricating bearings is well known in the art. These woven or knitted fabrics typically consist of fluoropolymer yarn and structural yarns (for example, cotton, polyester or glass fiber etc.).
U.S. Pat. Nos. 2,804,886 (White), U.S. Pat. No. 3,055,788 (Stanhope et al.), U.S. Pat. No. 3,037,893 (White) and GB 861,506 (Wright et al.) disclose the use of woven fluoropolymer fabric in friction applications. However, liners based on such fabrics are very expensive and typically limited to a thickness of about 0.127 mm or greater. Such woven fabrics known in the industry require complex and expensive manufacturing processes and are characterized by a significant resistance to heat flow. This heat resistance results in the bearings becoming overheated at or above relative speeds in the range of about 0.5 m/s causing increased levels of friction, thus reducing their service life, as indicated by a significant loss of liner material, thereby limiting their operating conditions and requiring more numerous replacements of such liners which results in increased production or operating costs.
Also, a nonwoven structure comprising fluoropolymer fibers and an amount of a binder sufficient to provide an appropriate level of wet and dry strength to the nonwoven structure is well known in the art. U.S. Pat. No. 3,114,672 (Schott) discloses such a material, wherein it can be used for the filtration of hot gases that are chemically active.
Also known in the art, is a pressboard material, which consists of m-aramid fiber, m-aramid fibrids, and fluoropolymer fiber. The pressboard material is primarily utilized as electrical insulation as is described in U.S. Pat. No. 4,888,578 (Hendren, Provost et al.).
The present invention offers the advantage of providing a saturable or open porous, nonwoven structure, which can be impregnated with a resin such that the resin permeates throughout the entire structure, comprising fluoropolymer fibers blended with other additional wettable structural organic fibers. Additionally, saturable nonwoven structures having the thickness of the present invention and the applications of the present invention have not been described in the art. Further, the present invention addresses the problems recognized within the industry that are encountered through the use of thick woven fabrics by providing a thin structure. Further, the present invention offers several other advantages in that it can be used at higher speeds than conventional materials, or it can be used at similar speeds as conventional materials yet have an increased service life, and it may be utilized at higher loading capacities.

Nonwoven material for low friction bearing surfaces


In a display and operating device for the functions of a menu, which includes multiple functions, in a vehicle having a screen display and input device for preselection of a function by dialing a respective screen symbol, all the functions of the menu may be displayed simultaneously on the screen display and may be preselected individually in a visually discernible manner by the input device. The preselected functions are jointly activatable in response to a switch command.

The invention relates to a display and operating device for the functions of a menu including multiple functions in a vehicle having a screen display and an input device for preselection of a function by selecting a respective screen symbol.
A device of the above-mentioned type is known from DE 38 36 555 A, wherein the functions of a menu are called up individually using an input device designed as a pushbutton-rotary switch. As a rule, only one function may be preselected per menu.
It is also known from DE 102 29 890 A that the functions of a menu may be displayed simultaneously on a screen. There, an option is provided for selecting individual functions therefrom and activating the individual functions. The selected individual functions, activated simultaneously when they are selected, are displayed on a separate screen.
The object of the present invention is to create a device of the above-mentioned type, wherein a greater freedom in the choice of functions of a menu is granted to a vehicle user by a simple procedure.
This object is achieved by the present invention through a display and operating device for the functions of a menu including multiple functions in a vehicle having a screen display and an input device for preselection of a function by selecting a respective screen symbol. All the functions of the menu may be displayed simultaneously on the screen display; a partial extent of these functions may be preselected; and this partial extent of preselected functions may be activated jointly in response to a switch command.
Since all the functions of the menu are displayed simultaneously on the screen display, the user of the vehicle has a complete overview of the input and operating options offered by that particular menu. The user need not make a decision from items one after the other without knowing the subsequent options. This prevents premature decisions and the associated attempts to correct these decisions. It is thus possible to define the effective functions of the menu rapidly and in a clear-cut manner.
In contrast with the device known from DE 102 29 890 A, the user also has an opportunity to correct his selection up until the end, i.e., until he implements the decision to, in fact, activate the selected functions. In the present invention, the selection process is uncoupled in time from the activation process.
One example may illustrate this. As part of the "Settings" menu, it should be possible to have warning information played back acoustically and/or visually. If the user of the vehicle receives the two alternatives "acoustic playback" and "visual playback" separately and one after the other, it is not usually possible to make a clear-cut decision without leaving doubt for the type of playback he would in fact like to have. However, if the two options are offered/presented simultaneously to the user of the vehicle, the decision will be made rapidly, correctly and in a clear-cut manner.
Further advantageous embodiments of the invention are described and claimed herein.
For the preselection of the partial extent of the functions relevant for the user, several alternatives may be considered. This partial extent may be identical to the partial extent activated in a previous operating phase.
The partial extent may also be automatically preselected in accordance with the respective operating state and/or the respective operating conditions of the vehicle. Operating states that may be mentioned include the instantaneous vehicle speed and driving in forward gear or in reverse gear. Operating conditions include, for example, ambient brightness, the inside or outside temperature, or the seat occupancy.
The partial extent may also be preselected individually. A cursor, such as that known from screen displays from the PC field, in particular may be used as input devices for the individual preselection of functions. The entire selection process can be performed especially rapidly if a pushbutton-rotary switch is used, so the screen symbols are approached one by one with a rotary movement and the functions thus approached can be selected by pressing the button.
The menu with its functions may likewise be called up on the screen display with such a pushbutton-rotary switch. Menu selection and changing between different menus are greatly improved by comparison with a switch allocated individually to each menu, such that when the switch is operated, the functions of the menu on the screen display can be displayed and/or activated simultaneously.
A visual emphasis of the functions then activated on the screen display may be associated with activation of the preselected functions as input means. According to the optical and technical circuit design, it may be possible to differentiate between preselection, selection and actual activation of the respective function.
The visual emphasis may also be limited in time following the input of the switch command. Thus, the visual support is provided only as long as is necessary and appropriate for safely performing the selection process.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.

Bayerische Motoren Werke Aktiengesellschaft


A fastener for use in soft tissue repair includes a resorbable polymer or suture core having one or more collagen bands in surrounding relation to the core. The bands are expandable between a dehydrated state for insertion and a hydrated state for healing, and are dimensioned and positioned to bring two sides of a tear into apposition to promote healing of the tear. The fastener insertion method includes driving an elongated tube across the tear, inserting a fastener down the tube until it breaches the tears and removing the tube, leaving the fastener in position to expand and promote healing of the tear.

1. Field of the Invention
The present invention relates to surgical devices and methods for repairing tissue tears and, more particularly, to a device and method for repairing a meniscal tear in a knee.
2. Description of Related Art
The menisci of the knee are C-shaped disks of cartilaginous tissue interposed between the condyles of the tibia and the femur. They are actually extensions of the tibia that serve to deepen the articular surfaces of the tibial plateau to accommodate better the condyles of the femur (see FIG. 1). The material of the menisci is collagenous, and the fibers are oriented generally circumferentially.
As the menisci were long considered functionless remains of leg muscle, injury to this tissue had been treated by their total removal, called meniscectomy. A better understanding of these structures, combined with improvements in arthroscopic surgical techniques, has led to the development of meniscal repair techniques.
Posterior peripheral tears of the menisci may be treated by an open technique, wherein sutures are placed along the tear. An arthroscopic technique may also comprise placing sutures along the tear, but in this method through a cannula.
There are a number of fastener-type devices that are known in the art. A surgical fastener is disclosed by Screiber (U.S. Pat. No. 4,873,976) that comprises a shaft having at least one barb for locking the shaft in place when inserted into soft tissue. Also described is an applicator consisting of a cylinder into which the fastener is placed and out of which the fastener is pushed when positioned at the tear site.
Bays et al. (U.S. Pat. Nos. 4,884,572 and 4,895,148) describe a surgical-repair tack and applicator and method of using them. The tack has a barb member and is made of biodegradable material having a degradation time selected to coincide with the healing time of the tissue. In an alternate embodiment, the tack's barb comprises a continuous helical barb.
The method and apparatus for repairing a meniscal tear disclosed by Winters (U.S. Pat. No. 5,059,206) comprises a fastener having protrusions or barbs that is applied to a meniscal tear with a delivery device. The delivery device has a flexible tip that is manipulable through a curved radius to enable the surgeon to insert the device into the central part of the knee and then extend the fastener radially outward into and across a meniscal tear.
A fastener, driving device, and method have been described by Justin and Winters (U.S. Pat. Nos. 5,569,252 and a later issued patent) wherein the fastener has a helical protrusion that is advanced across a tear in a screwing motion. In the latter patent, the protrusion has a variable-pitch for bringing two sides of the tear into apposition as the fastener is advanced across the tear. The fastener material preferably is a bioabsorbable, biocompatible, nontoxic plastic that is specifically designed to bioabsorb generally within the time span of the healing process. A delivery device for introducing the fastener was also provided that includes an elongated needle rotationally coupled with the fastener.
Stone et al. (Clin. Orthopaed. Rel. Res., No. 252, March 1990) introduced a resorbable collagen template for induced meniscal regeneration.
No method of repairing meniscal tissue with a device made from a core of bioabsorbable material and outer tubes or bands of expanding collagen is known to have been disclosed, however.

Device for repairing a meniscal tear in a knee and method


A bidirectional text display method embodied in a functional programming language which first assigns bidirectional attributes to a logical character stream. Next, through explicit processing, level numbers are assigned, honoring any directional overrides present in the logical character stream. Subsequent weak and neutral type processing potentially causes attribute types to change based upon surrounding attribute types. Then, implicit processing assigns final level numbers to the stream which control reordering. Finally, reordering processing produces a sequence of characters in display order. By separating the facets of layout dealing with reordering from those that are concerned with rendering, such as line breaking, glyph selection, and shaping, the Haskell-based method is more discernible and comprehendable, thereby allowing it to be more useful as a model upon which others may base bidirectional implementations.

1. Field of the Invention
This invention relates to the technologies of computer displays and interpretation of file and data for display on a computer. This invention especially relates to the technologies of bi-directional display methods for displaying portions of data which require orientation from left-to-right and from right-to-left to support various international character sets and languages.
2. Description of the Related Art
Prior to the introduction of rich encoding schemes such as Unicode and ISO10646, most text streams consisted of characters originating from a single script. Traditionally an encoding was comprised of one national script plus a subset of the Latin script (ASCII 7) which fit within the confines of an 8 bit character type. In such an environment, presentation of text is a relatively trivial matter.
For the most part, the order in which a program stores its characters (logical order) is equivalent to the order in which they are visually presented (display order). Thus, there is a direct correlation between the logical order and display order. Exceptions to this rule include scripts which are written from right to left, such as Arabic, Hebrew, Farsi, Urdu, and Yiddish.
One existing method to solve this problem is to require computer users, such as computer programmers or web browser users, to enter characters in display order. This is no problem for users of left-to-right languages. However, for users of right-to-left languages, this requires the user to enter the characters and words in "reverse order". For example, to create a text stream containing Arabic characters, the user must enter them backwards.
This solution is not elegant, and it becomes cumbersome when right-to-left and left-to-right scripts are intermixed, creating bi-directional scripts.
Another solution known in the art is to allow users to enter text in logical order, but to require them to use some explicit directional formatting codes within the script, for example, 0x202B and 0x202A in Unicode, for segments of text that run contrary to the base text direction. As this is acceptable in some instances, it has problems in practice, as well. First, it is undefined what a computer should do with the explicit control codes in tasks other than displaying the script. This may cause problems when these formatting codes are received by searching algorithms, or when they are interchanged between systems.
These explicit formatting codes require specific code points to be set-aside for them, as well. In some encodings, this may be unacceptable due to the fixed number of code points available and the number of code points required to represent the script itself.
Ideally, a system of encoding mixed direction scripts would maintain the flexibility of entering characters in logical order while still achieving the correct visual appearance and display order. Such algorithms do exist, and are called "implicit layout algorithms".
Implicit layout algorithms require no explicit directional codes nor any higher order protocols. These algorithms can automatically determine the correct visual layout by simply examining the logical text stream. Yet in certain cases correct layout of a text stream may still remain ambiguous. Consider the following example in TABLE 1 in which Arabic letters are represented by upper case Latin characters.
TABLE 1Ambiguous layoutfred does not believe TAHT YAS SYAWLA I
In the absence of context, such as a base or paragraph direction, there are two possible ways to display the sentence. When displayed from left to right, it appears as "Fred does not believe I always say that", and when displayed from right to left, it appears as "I always say that Fred does not believe". As evident from this example, the two interpretations can represent completely different meanings, and may give no clue whatsoever that there has been an error in the display of the script.
The Unicode Bi-directional Algorithm rectifies such problems by providing a mechanism for unambiguously determining the visual representation of all raw streams of Unicode text. The algorithm is based upon existing implicit layout algorithms and is supplemented by the addition of explicit directional control codes.
Generally the Unicode implicit rules are sufficient for the layout of most text streams. However, there are cases in which the Unicode algorithm may give inappropriate or inaccurate display results. For example, a telephone number appearing in a stream of Arabic letters "MY NUMBER IS (321)713-0261." This should not be rendered as a mathematical expression as show in TABLE 2. As demonstrated, without knowledge of the use of the numbers in this context, the correct display cannot correctly be determined.
TABLE 2Rendering numbersIncorrect display:0261-713 (321) SI REBMUN YMCorrect display:(321) 713-0261 SI REBMUN YM
Various implementations of the Unicode Bi-directional Algorithm have been proposed in technical reports, such as Unicode Technical Report #9, including "Pretty Good Bidi Algorithm" (PGBA), "Free Implementation of the Bidi Algorithm" (FriBidi)], "IBM Classes for Unicode" (ICU), Java 1.2, Unicode Java Reference, and Unicode C Reference.
Currently, there exist two reference implementations of the Unicode Bidirectional algorithm, one in Java and the other in C, as well as printed textual descriptions contained in technical reports such as Unicode Technical Report #9.
Upon our testing of the reference implementations of the Unicode Bidirectional algorithm on a large number of concise and carefully crafted test cases of basic bidirectional text, several problems and ambiguous results are found.
To simulate Arabic and Hebrew input/output, a simple set of rules can be utilized. These rules make use of characters from the Latin-1 character set. The character mappings allow Latin-1 text to be used instead of real Unicode characters for Arabic, Hebrew, and control codes. This is an enormous convenience in writing, reading, running and printing the test cases. This form is the same as the one used by the Unicode Bidirectional Reference Java Implementation, as shown in TABLE 3.
Unfortunately not all the implementations adhere to these rules in their test cases. To compensate for this, changes were made to some of the implementations.
TABLE 3Bidirectional character mappingsTypeArabicHebrewMixedEnglishLa–za–za–za–zALA–ZA–MRA–ZN–ZAN0–95–9EN0–90–40–9LRE[[[[LRO{{{{RLE]]]]RLO}}}}PDF{circumflex over ( )}{circumflex over ( )}{circumflex over ( )}{circumflex over ( )}NSM~~~~
In the Unicode C reference implementation, additional character mapping tables were added to match those of the Unicode Java Reference implementation. Also the bidirectional control codes were remapped from the control range 0x00–0x1F to the printable range 0x20–0x7E. This remapping allowed test results to be compared more easily.
In PGBA and FriBidi, the character attribute tables were modified to match the character mappings outlined in TABLE 3. However, the strategy we used for evaluation of ICU and Java was slightly different. In the ICU and Java test cases, the character types are used rather than a character mapping. So, in places where our test cases required a specific type, that type was simply used rather than a character mapping.
The test cases employed are presented in TABLES 4 through 7. The "source" column of each table shows the test case script input and a test case number, and the "expected" column sets forth what the correct display order output should have been.
TABLE 4Arabic Charmap TestsSourceExpected1car is THE CAR in arabiccar is RAC EHT in arabic2CAR IS the car IN ENGLISHHSILGNE NI the car SI RAC3he said "IT IS 123, 456, OK"he said "KO ,456 ,123 SI TI"4he said "IT IS (123, 456), OK"he said "KO ,(456 ,123) SI TI"5he said "IT IS 123,456, OK"he said "KO ,123,456 SI TI"6he said "IT IS (123,456), OK"he said "KO ,(123,456) SI TI"7HE SAID "it is 123, 456, ok""it is 123, 456, ok" DIAS EH8<H123>shalom</H123><123H/>shalom<123H>9HE SAID "it is a car!" AND RANNAR DNA "!it is a car" DIASEH10HE SAID "it is a car!x"NAR DNA "it is a car!x" DIAS AND RANEH11−2 CELSIUS IS COLDDLOC SI SUISLEC −212SOLVE 1*5 1 − 5 1/5 1 + 55 + 1 5/1 5 − 1 5*1 EVLOS13THE RANGE IS 2.5..55..2.5 SI EGNAR EHT14IOU $1010$ UOI15CHANGE - 10%%10- EGNAHC16- 10% CHANGEEGNAHC %10-17he said "IT IS A CAR!"he said "RAC A SI TI!"18he said "IT IS A CAR!X"he said "X!RAC A SI TI"19(TEST) abcabc (TSET)20abc (TEST)abc (TSET)21#@$TESTTSET $@#22TEST 23 ONCE abcabc ECNO 23 TSET23he said "THE VALUES ARE 123,he said "KO ,789 ,456 ,456, 789, OK"123 ERA SEULAV EHT".24he said "IT IS A bmw 500, OK."he said "A SI TI bmw KO ,500."
TABLE 5Hebrew Charmap TestsSourceExpected1HE SAID "it is 123, 456, ok"."it is 123, 456, ok" DIAS EH2<H123>shalom</H123><123H/>shalom<123H>3<h123>SAALAM</h123><h123>MALAAS</h123>4−2 CELSIUS IS COLDDLOC SI SUISLEC −25-10% CHANGEEGNAHC -10%6TEST ~~~23%%% ONCE abcabc ECNO 23%%%~~~ TSET7TEST abc ~~~23%%% ONCEabc ECNO abc ~~~23%%%abcTSET8TEST abc@23@cde ONCEECNO abc@23@cde TSET9TEST abc 23 cde ONCEECNO abc 23 cde TSET10TEST abc 23 ONCE cdecde ECNO abc 23 TSET11Xa 2 ZZ a 2X
TABLE 6Mixed Charmap TestsSourceExpected1A~~~~A2A~a~a~~A3A11A4A11 A5A~11~A6117a1a18N11 N9A~~ 11 ~~A10A~a1a1~A11N11N12a1a113A~N11N~A14NOa1a1ON151/2½161, 21, 2175, 65, 618A1/22/1A19A1, 51, 5A20A1, 21, 2A211, .21, .2221, A22A, 123A5, 15, 1A24+$1+$1251+$1 + $265 + 15 + 127A + $11$ + A28A1 + $$ + 1A291 + /21 + /2305+5+31+$+$32N + $1+$1N33+12$+12$34a/1a/1351, 51, 536+5+5
TABLE 7Explicit Override TestsSourceExpected1a}}}defafed2a}}}DEFaFED3a}}}defDEFaFEDfed4a}}}DEFdefafedFED5a{{{defadef6a{{{DEFaDEF7a{{{defDEFadefDEF8a{{{DEFdefaDEFdef9A}}}deffedA10A}}}DEFFEDA11A}}}defDEFFEDfedA12A}}}DEFdeffedFEDA13A{{{defdefA14A{{{DEFDEFA15A{{{defDEFdefDEFA16A{{{DEFdefDEFdefA17{circumflex over ( )}{circumflex over ( )}abcabc18{circumflex over ( )}{circumflex over ( )}}abccba19}{circumflex over ( )}abcabc20{circumflex over ( )}}{circumflex over ( )}abcabc21}{circumflex over ( )}}abccba22}{circumflex over ( )}{abcabc23}{circumflex over ( )}{circumflex over ( )}}abccba24}}abcDEFFEDcba
All implementations were tested by using the test cases from TABLES 4 through 6. The implementations that support the Unicode directional control codes (LRO, LRE, RLO, RLE, and PDF) were further tested using the test cases from TABLE 7. At this time, the directional control codes are only supported by ICU, Java 1.2, Unicode Java reference, and Unicode C reference.
When the results of the test cases were compared, the placement of directional control codes and choice of mirrors was ignored. This is permitted as the final placement of control codes is arbitrary and mirroring may optionally be handled by a higher order protocol.
TABLES 8–10 detail the test result differences among the implementations with respect to the expected results. Only PGBA, FriBidi and the Unicode C implementations returned results that were different from the expected results; the Unicode Java reference, Java 1.2, and ICU passed all test cases.
TABLE 8aArabic Test Differences for PGBA 2.44he said "KO ,)456 ,123( SI TI"6he said "KO ,)123,456( SI TI"121 + 5 1/5 1 − 5 5*1 EVLOS14$10 UOI15%-10 EGNAHC16EGNAHC %-1019abc )TSET(24he said "A SI TI bmw 500, KO."
TABLE 8b.Arabic Test Differences for FriBidi 1.122SI RAC the car NI ENGLISH7"ok ,456 ,123 it is" DIAS EH8<123H>shalom</123H>9DIAS EH "it is a car!" DNA RAN10DIAS EH "it is a car!x" DNA RAN11-SI SUISLEC 2 COLD1510- EGNAHC%16-10% CHANGE19(TSET) abc21#@$ TEST22ECNO 23 TSET abc
TABLE 8c.Arabic Test Differences for Unicode C Reference7"ok ,456 ,123 it is" DIAS EH11DLOC SI SUISLEC 2–12
TABLE 9Hebrew Test DifferencesPGBA 2.4FriBidi 1.125EGNAHC %- 106abc ECNO %%%23~~~TSET7abc ECON %%%23~~~abc TSET11Z 2 aXa 2X
TABLE 10Mixed test differencesPGBAFriBidi 1.121A~~2~a~A~Aa~101a~A~Aa1141a~A181/2A1/2A195.1A212, 1231, 5A27+$1A281 + $A3215N355, 1
In the PGBA reference implementation, types AL and R are treated as being equivalent. This in itself does not present a problem as long as the data stream is free of AL and EN (European number). However, a problem arises when AL is followed by a EN. For example, test case 18 from TABLE 6. In this situation, the ENs should be treated as AN's (Arabic number) and not left as EN's.
The handling of NSM is also different in PGBA. PGBA treats NSM as being equal to ON (other neutral). This delays the handling of NSM until the neutral type resolution phase rather than in the weak type resolution phase. By delaying their handling, the wrong set of rules are used to resolve the NSM type. For example, in test case 2 from TABLE 6 the last NSM should be treated as type L instead of type R.
There are a few problems with the FriBidi implementation, as well. Specifically, when an AL is followed by a EN the EN is not being changed to type AN. See test case 18 in TABLE 6. This is the same symptom as was found in PGBA, but the root cause is different. In FriBidi, step W2 (weak processing phase rule two) the wrong type is being examined it should be type EN instead of type N. Additionally, there is a problem in determining the first strong directional character. The only types that are recognized as having a strong direction are types R and L. Type AL should also be recognized as a strong directional character. For example, when test case 1 from TABLE 6 is examined FriBidi incorrectly determines that there are no strong directional characters present. It then proceeds to default the base direction to type L when it should actually be of type R. This problem also causes test cases 2, 9, and 11 from TABLE 4 to fail.
The greatest hindrance to the creation of a method for converting logical data streams to display streams lies in the problem description. The problem of bidirectional layout is ill defined with respect to the input(s) and output(s).
Certainly the most obvious input is the data stream itself. Several situations require additional input in order to correctly determine the output stream. For example, in Farsi mathematical expressions are written left to right while in Arabic they are written right to left. This may require a special sub input (directional control code) to appear within stream for proper handling to occur. If it becomes necessary to use control codes for obtaining the desired results the purpose of an algorithm becomes unclear.
The situation becomes even more cloudy when one considers other possible inputs (paragraph levels, line breaks, shaping, directional overrides, numeric overrides, etc.) Are to be treated as separate inputs? If they are treated as being distinct, when, where and how should they be used? Determining the output(s) is not simple either. The correct output(s) is largely based on the context in which an algorithm be used. If an algorithm is used to render text, then appropriate outputs might be a glyph vector and a set of screen positions. On the other hand, if an algorithm is simply being used determine character reordering, then an acceptable output might just be a reordered character stream.
The Unicode Bidirectional algorithm has gone through several iterations over the years. The current textual reference been greatly refined. Nevertheless, we believe that there is room for improvement. Implementing a bidirectional layout algorithm is not a trivial matter even when one restricts an implementation to just reordering. Part of the difficulty can be attributed to the textual description of the algorithm. Additionally there are areas that require further clarification.
As an example consider step L2 of the Unicode Bidirectional Reference Algorithm. It states the following, "From the highest level found in the text to the lowest odd level on each reverse any contiguous sequence of characters that are at level or higher." This has more than one possible interpretation. It could mean that once the highest level has been found and processed the next level for processing should one less than the current level. It could also be interpreted meaning that the next level to be processed is the next lowest level actually present in the text, which may be greater one less than the current level. It was only through an examination of Unicode's Java implementation that we were to determine the answer.
There are also problems concerning the bounds of the Uni-code Bidirectional Algorithm. In the absence of higher order protocols it is not always possible to perform all the steps of Unicode Bidirectional Algorithm. In particular, step L4 requires mirrored characters to be depicted by mirrored glyphs their resolved directionality is R. However, glyph selection requires knowledge of fonts and glyph substitution tables. One possible mechanism for avoiding glyph substitutions is to perform mirroring via character substitutions. In this approach mirrored characters are replaced by their corresponding character mirrors. In most situations this approach yields the same results. The only drawback occurs when a mirrored character does not have its corresponding mirror encoded in Unicode. For example, the square root character (U221A) does not have its corresponding mirror encoded.
Such situations have placed developers in a quandary. One solution is to use the implementations (Java and C) as a reference. But these implementations don't agree in every case. Furthermore the implementations have different goals. The Java implementation follows the textual reference closely while the C implementation offers performance improvements.
However, if computer source code is to be used as a reference design, then source code that is more attuned to describing these types of methods and algorithms is required. The flexibility, extensibility, and understandability of the imperative language references causes these references to be inadequate.
For example, using the imperative language reference, it matters what character encoding one uses (UCS4, UCS2, or UTF8). In "C", the size of types are not guaranteed to be portable, making C unsuitable as a reference. In the Java, reference implementation the ramifications of moving to UCS4 are unclear.
Therefore, there is a need in the art for a new reference method for bidirectional text script interpretation for display, which avoids the errors in interpretation of the existing references, as well as provides a framework upon which future, improved models may be realized. Preferably, the new method should separate details that are not directly related to the method such that text and character reordering is completely independent from character encoding.


Generating user authentication challenges based in part on preferences of one or more contacts of a user includes receiving an authentication request from a user. One or more contacts of the user associated with the authentication request are determined. One or more preferences of the close contact or contacts are determined. An authentication challenge based on the one or more preferences of one or more of the user's contacts is generated. The authentication request is allowed or denied based on the completion on the authentication challenge.

Websites provide the capability for users to login to view their personal information, or other information that the user wants to keep private, or even access the functionality provided by the website. An added level of security is established by generating a challenge to the user attempting to login. Generally, the challenge is the generation of a secret question or the generation of a Completely Automated Public Turning test to tell Computer and Humans Apart (CAPTCHA) to guard against possible fraudulent login attempts, and login by bots and other automated devices; although, other methods exist. One other method utilizes the user's own preferences in an authentication challenge.

Generating authentication challenges based on preferences of a user's contacts


The invention provides a transgenic animal carrying two transgenes, one encoding a human decay accelerating factor (hDAF) and the other encoding a human heme oxygenase-1 (hHO)-1, which are useful for providing cells, tissues or organs therefrom for xenotransplantation.

Because of the insufficient supply of human organs, various xenogeneic sources have been studied for transplantation (Cooper D K. Transplant Proc. 1992; 24: 2393-2396). In this regard, a pig model for transplantation has been developed. However, the use of pigs as an organ source is limited because transplantation of pigs' organs to human bodies results in various immunological rejections to the grafted organs in the human bodies, including hyperacute rejection, delay xenograft rejection (DXR) including acute vascular rejection (also called delay vascular rejection) and acute cellular rejection, and chronic rejection (Nowak R., Science 1994; 266: 1148-1151). It was found that human decay accelerating factor (hDAF, also named CD55; Cozzi et al., Transplant Proc. 1994; 26: 1402-1403 and McCurry et. al., Nat. Med. 1995; 1: 423-427), membrane cofactor protein (MCP; McCurry et. al. supra), and CD59 (McCurry et. al. supra; and Fodor et al., Proc. Natl. Acad. Sci. USA 1994; 91: 11153-11157) can down-regulate the pathway of complement activation, and thus conquers hyperacute rejection to the organs from transgenic pigs. In ex-vivo perfusion studies, hyperacute rejection was prevented in the heart (Schmoeckel et al. Transplantation 1996; 62: 729-734; and Byrne et al., Transplantation 1997; 63: 149-155), kidney (Byrne et al. Supra, Kroshus et al., Transplantation 1996; 61: 1513-1521, Storck et al., Transplantation 1997; 63: 304-310) and lung (Kroshus et al. Supra, Storck et al. Supra, and Pierson R et al., J. Heart Lung Transplant 1997; 16: 231-239) of the transgenic pig introduced with a gene encoding hDAF or CD59. It was also demonstrated that expression of a functional human CD59 on cardiac endothelium of a transgenic pig inhibits the assembling of membrane attack complex, and reduces damages on the heart tissue of a baboon, to which the heart of the transgenic pig was transplanted (Diamond et al., Transplantation 1996; 61: 1241-1249). In addition, the Imutran Limited has provided data showing that transplantation of the kidney and heart from a hDAF transgenic pig to a non-human primate recipient allows the recipient to maintain a life period of over 78 days and one month, respectively (Cozzi et al., Transplantation 2000; 70: 15-21, and Vial et al., J. Heart Lung Transplant. 2000; 19: 224-229.)
In addition, problems regarding natural antibodies generated in human recipients against the epitope of gal-alpha1, 3-gal (i.e., alpha-Gal) carried by endothelial cells of donors' organs remain to be solved. Alpha-Gal is expressed in various tissues, especially the endothelial cells of capillaries, arterioles and arteries, and also in the parencyma of liver, proximal convoluted tubules, glomerulii and collecting ducts of kidney, alveoli of lung, and pancreas ducts (Sandrin M. S. and I. F. C. McKenzie. 1999. Modulation of α-Gal epitope expression on porcine cells. In: α-Gal and anti-Gal: α-1,3-Galactosyltransferase, α-Gal epitope, and the nature anti-Gal antibody. pp. 311-337). The synthesis of the epitope of alpha-Gal depends on the activity of the enzyme, alpha1, 3-galactosyltransferase (i.e., al, 3-GT) (Galili, U. Immun. Series, 1991; 55:355-337). This enzyme is active in New World monkeys (Galili, U. et al., J. Biol. Chem. 1988; 263:17755-17762), in most species including microbias (Larsen, R. D. et al., Proc. Natl. Acad. Sci. USA. 1989; 86:8227-8231), but not in ape, Old World monkeys and human (Galili, U. supra), wherein in human the α1, 3-GT gene is present as a processed pseudogene, which is non-functional due to frame shift mutations (Larsen, R. D. et al., J. Biol. Chem. 1990; 265:7055-7061). The gene encoding α1, 3-GT has been analyzed in mice (Sandrin, M. S. et al., Xenotransplantation 1994; 1:81-88.) and pigs (Joziasse, D. H. et al., J. Biol. Chem. 266: 6991-6998). It has been suggested that organs of genetically modified pigs in which the α1, 3-GT gene is knocked out might be suitable for xenograft. Recently, α1, 3-GT genetic knockout heterozygote (Dai Y et al., Nature Biotech. 2002; 20: 251-255, and Lai L et al., Science 2002; 295: 1089-1092) and homozygote (Phelps C J et al., Science 2002; 299:411-414) pigs have been cloned. However, the applicability of the α1, 3-GT genetic knockout pigs in xenograft remains to be elucidated. Alternatively, a strategy for competitively inhibiting the alpha-Gal expression in pigs' organs by transgenesis of alpha 1, 2-fucosyltransferase was reported but failed since the alpha-Gal was still expressed with a high density in the pigs' tissues (Sharma A et al., Proc. Natl. Acad. Sci. USA 1996; 93: 7190-7195).
Therefore, there is a need to develop a transgenic animal for providing a graft to be transplanted to a human subject in need thereof, wherein one or more immunological rejections to the graft in the human subject are reduced.
Heme oxygenases (HOs), rate-limiting enzymes in heme catabolism, also named HSP32, belong to members of heat shock proteins, wherein the heme ring is cleaved into ferrous iron, carbon monoxide (CO) and biliverdin that is then converted to bilirubin by biliverdin reductase. Three isoforms of HOs, including HO-1, HO-2 and HO-3, have been cloned. The expression of HO-1 is highly inducible, whereas HO-2 and HO-3 are constitutively expressed (Maines M D et al., Annual Review of Pharmacology & Toxicology 1997; 37:517-554, and Choi A M et al., American Journal of Respiratory Cell & Molecular Biology 1996; 15:9-19). An analysis of HO-1−/− mice suggests that the gene encoding HO-1 regulates iron homeostasis and acts as a cytoprotective gene having potent antioxidant, anti-inflammatory and anti-apoptotic effects (Poss K D et al., Proceedings of the National Academy of Sciences of the United States of America 1997; 94:10925-10930, Poss K D et al., Proceedings of the National Academy of Sciences of the United States of America 1997; 94:10919-10924, and Soares M P et al., Nature Medicine 1998; 4:1073-1077). Similar findings were recently described in a case report of HO-1 deficiency in humans (Yachie A et al., Journal of Clinical Investigation 1999; 103:129-135). The molecular mechanisms responsible for the cytoprotective effects of HO-1, including anti-inflammation, anti-oxidation and anti-apoptosis, are mediated by its' reaction products.
HO-1 expression can be modulated in vitro and in vivo by protoporphyrins with different metals. Cobalt protoporphyrins (CoPP) and iron protoporphyrins (FePP) can up-regulate the expression of HO-1. In contrast, tin protoporphyrins (SnPP) and zinc protoporphyrins (ZnPP) inhibit the activity of HO-1 at the protein level. Recently, it has been proved that the expression of HO-1 suppresses the rejection of mouse-to-rat cardiac transplants (Sato K et al., J. Immunol. 2001; 166:4185-4194), protects islet cells from apoptosis, and improves the in vivo function of islet cells after transplantation (Pileggi A et al., Diabetes 2001; 50: 1983-1991). It has also been proved that administration of HO-1 by gene transfer provides protection against hyperoxia-induced lung injury (Otterbein L E et al., J Clin Invest 1999; 103: 1047-1054), upregulation of HO-1 protects genetically fat Zucker rat livers from ischemia/reperfusion injury (Amersi F et al., J Clin Invest 1999; 104: 1631-1639), and ablation or expression of HO-1 gene modulates cisplatin-induced renal tubular apoptosis (Shiraishi F et al., Am J Physiol Renal Physiol 2000; 278:F726-F736). In transgenic animal models, it was shown that over-expression of HO-1 prevents the pulmonary inflammatory and vascular responses to hypoxia (Minamino T et al., Proc. Natl. Acad. Sci. USA 2001; 98:8798-8803) and protects heart against ischemia and reperfusion injury (Yet S F, et al., Cir Res 2001; 89:168-173).
So far, no transgenic pigs carrying both hDAF and hHO-1 transgenes have been developed for xenotransplantation, and no related teachings and motivation have been provided.

Transgenic pigs carrying both hHO-1 and hDAF transgenes for xenotransplantation