Abstract: The present disclosure provides a pellet. In an embodiment, the pellet includes a body having a first end and an opposing second end. The body is composed of a polymeric material. The body has a length and a diameter (body diameter). A channel having a diameter (channel diameter), extends through the body from the first end to the second end. The pellet has a channel diameter-to-body diameter ratio from 0.05 to 0.45. The present disclosure also provides a process for soaking the pellet in a liquid additive and forming a loaded pellet with the additive in the pellet body.

Abstract: A charge-modified particle comprising the inorganic core and a shell surrounding the inorganic core, wherein the shell comprises a copolymer comprising monomeric units corresponding to free-radically polymerizable monomers, and wherein at least one of the monomeric units comprises a substituted benzotriazolylphenolate salt. Methods of making the charge-modified particle by admicellar polymerization are also disclosed.

Abstract: A polymerizable system includes a curable composition and one or more encapsulated initiator particles. The curable composition can include one or more 1,1-disubstituted alkene compounds and the encapsulated initiator particles can include one or more polymerization initiators encapsulated by a cured composition. The cured composition includes one or more 1,1-disubstituted alkene compounds.

Abstract: The present invention provides for transdermal delivery devices having microneedle arrays, as well as methods for their manufacture and use. In one embodiment, a transdermal delivery device is provided. The transdermal delivery device includes a polymer layer which has microneedles projecting from one of its surfaces. The microneedles are compositionally homogenous with the polymer base layer.

Abstract: The present invention relates to a method for manufacturing solid round emulsion beads by dropping liquid emulsion into a cryogenic freezing refrigerant. The obtained solid round emulsion beads can be stored and used at a low temperature. The solid round emulsion beads can be coated with a solution containing a composition which is solid at room temperature or which can form gel. The emulsion beads can be prepared by using liquid emulsion containing additional composition, which is solid at room temperature or can form gel, in the water phase of oil-in-water (O/W) emulsion or the oil phase of oil-in-water (W/O) emulsion. The emulsion beads prepared by the present invention can maintain its shape without swelling and/or damage but with stability and does not give any grainy feeling when the liquid emulsion was applied on the skin.

Abstract: Heat-expandable microspheres having an almost spherical shape and high expansion performance and exhibiting good workability when mixed with a resin, a process for producing the heat-expandable microspheres, and applications thereof. The heat-expandable microspheres include a thermoplastic resin shell and a blowing agent encapsulated therein and vaporizable by heating. The thermoplastic resin is produced by polymerizing a polymerizable component containing a methacrylate monomer and a carboxyl-containing monomer, and optionally containing a nitrile monomer in an amount ranging from 0 to 30 parts by weight to 100 parts by weight of the total amount of the methacrylate monomer and the carboxyl-containing monomer. The blowing agent contains a hydrocarbon having at least 8 carbon atoms per molecule.

Abstract: The present invention relates to the field of heat sensitive optically variable inks and tamper indicating markings obtained thereof. The present invention relates to the field of irreversible changes in color and/or changes in structure upon a tampering attempt against articles or items comprising said tamper indicating markings through the use of temperature variation. In particular, the present invention provides optically variable ink compositions comprising a plurality of optically variable pigment particles and a plurality of thermally expandable spheres; tamper indicating marking comprising the optically variable ink compositions described herein; their uses as a proof of an illegal action as well as methods for detecting a tampering activity of a marking including the optically variable ink composition described herein.

Abstract: A controlled release particle includes a core formed by suspension polymerization of a core ingredient component containing an antibiotic compound and a first polymerizable vinyl monomer, and containing a first polymer of the first polymerizable vinyl monomer and the antibiotic compound present in the first polymer; and a shell formed by suspension polymerization of a second polymerizable vinyl monomer having affinity with water of the same or higher than that of the first polymerizable vinyl monomer, containing a second polymer obtained from the second polymerizable vinyl monomer, and covering the core.

Abstract: An auto-repairing photoresist composition comprises 1 to 10 wt % of microcapsule having a capsule wall and a capsule core based on the total weight of the photoresist composition, wherein the capsule wall includes an alkali-insoluble resin, and the capsule core includes: 10 to 60 wt % of a photo-curable unsaturated resin oligomer; 10 to 50 wt % of a photo-curable monomers; 10 to 70 wt % of a first black pigment paste; 0.1 to 10 wt % of a first photo-initiator; and 0.1 to 5 wt % of a coupling agent, based on the total weight of the capsule core. The photoresist composition of embodiments of the present invention can be used for preparation of Black Matrix, and has an auto-repairing property to improve substantially the pass yield of product. A method of preparing the photoresist composition, a color filter substrate, and a display apparatus are also disclosed.

Abstract: Polymeric particles comprising a polymeric matrix that has been formed from a blend of monomers comprising a first monomer which is an ethylenically unsaturated ionic monomer and a second monomer which is an ethylenically unsaturated hydrophobic monomer which is capable of forming a homopolymer of glass transition temperature in excess of 50° C., wherein secondary particles are distributed throughout the matrix, in which the secondary particles comprise a hydrophobic polymer that has been formed from an ethylenically unsaturated hydrophobic monomer which is capable of forming a homopolymer of glass transition temperature in excess of 50° C. and optionally other monomers, which hydrophobic polymer is different from the polymeric matrix. Also claimed is a process for preparing particles. The particles have improved shatter resistance. Preferably the polymeric particles comprise an active ingredient, especially a colorant.

Abstract: The present invention relates to a method for preparing capsules comprising a liquid core, a stiffened intermediate envelope and a gelled external envelope, comprising a step of forming a multi-component liquid drop, a gelification step and a stiffening step. The present invention also relates to a method for preparing capsules comprising a liquid core and a stiffened envelope, comprising a step of forming a multi-component liquid drop, a gelification step, a stiffening step and a depolymerizing step.

Abstract: A thermoplastic molding composition is provided, which comprises A) from 30 to 90% by weight of at least one thermoplastic polymer, B) from 10 to 70% by weight of microcapsules with a capsule core made of latent-heat-accumulator material and a polymer as capsule wall, where the latent-heat-accumulator material has its solid/liquid phase transition in the temperature range from ?20° C. to 120° C.

Abstract: The present invention relates to benefit agent containing delivery particles, compositions comprising said particles, and processes for making and using the aforementioned particles and compositions. When employed in compositions, for example, cleaning or fabric care compositions, such particles increase the efficiency of benefit agent delivery, there by allowing reduced amounts of benefit agents to be employed. In addition to allowing the amount of benefit agent to be reduced, such particles allow a broad range of benefit agents to be employed.

Abstract: Encapsulated cure systems are provided wherein a curative is incorporated into a solid or semi-solid carrier material whereby mere fracturing or failure of the capsule wall encapsulating such cure systems will not provide for or allow sufficient release of the curative. Also provided are adhesive systems incorporating said encapsulated cure systems.

Abstract: The invention provides a three layered reprographic paper having improved strength, stiffness and curl resistance properties, and a method for making same. The paper has a central core layer made largely of cellulose and bulked with a bulking agent such as a diamide salt. A starch-based metered size press coating is pressed on both sides of the core layer, wherein the starch has a high solid content. The coating forms a three layered paper having an I-beam arrangement with high strength outer layers surrounding a low density core.

Abstract: The present invention concerns microcapsules comprising a capsule core and a capsule wall, the capsule wall being constructed from 30% to 90% by weight of one or more C1-C24-alkyl esters of acrylic and/or methacrylic acid, acrylic acid, methacrylic acid and/or maleic acid (monomers I), 10% to 70% by weight of a mixture of divinyl and polyvinyl monomers (monomers II), the fraction of polyvinyl monomers being in the range from 2% to 90% by weight based on the monomers II, and also 0% to 30% by weight of one or more miscellaneous monomers (monomer III), all based on the total weight of the monomers, a process for their production and their use in textiles, bindered building materials and heat transfer fluids.

Abstract: The present invention relates to a sheet-like construction element composed of composite material, comprising two metallic outer layers, a rigid polyurethane foam layer, and a compact polyurethane layer which comprises microcapsules with a capsule core composed of latent-heat-accumulator material, and also to a process for its production, and to its use.

Abstract: The invention provides a three layered reprographic paper having improved strength, stiffness and curl resistance properties, and a method for making same. The paper has a central core layer made largely of cellulose and bulked with a bulking agent such as a diamide salt. A starch-based metered size press coating is pressed on both sides of the core layer, wherein the starch has a high solid content. The coating forms a three layered paper having an I-beam arrangement with high strength outer layers surrounding a low density core.

Abstract: The present invention concerns microcapsules comprising a capsule core and a capsule wall, the capsule wall being constructed from 30% to 90% by weight of one or more C1-C24-alkyl esters of acrylic and/or methacrylic acid, acrylic acid, methacrylic acid and/or maleic acid (monomers I), 10% to 70% by weight of a mixture of divinyl and polyvinyl monomers (monomers II), the fraction of polyvinyl monomers being in the range from 2% to 90% by weight based on the monomers II, and also 0% to 30% by weight of one or more miscellaneous monomers (monomer III), all based on the total weight of the monomers, a process for their production and their use in textiles, bindered building materials and heat transfer fluids.

Abstract: The invention relates to thermally expandable thermoplastic microspheres comprising a polymer shell made from ethylenically unsaturated monomers encapsulating a propellant, said ethylenically unsaturated monomers comprising from 20 to 80 wt % of acrylonitrile, from 20 to 80 wt % of monomers selected from the group consisting of esters of acrylic acid, from 0 to 10 wt % of methacrylonitrile, from 0 to 40 wt % of monomers selected from the group consisting of esters of methacrylic acid, the total amount of acrylonitrile and esters of acrylic acid constituting from 50 to 100 wt % of said ethylenically unsaturated monomers, and said propellant comprising at least one of methane, ethane, propane, isobutane, n-butane and isopentane. The invention further relates to the production and use of the microspheres.

Abstract: To provide capsular fine particles comprising an olefinic polymer which have a uniform particle size distribution and a uniform particle size, and which are spherical and free from the coagulation between particles. Capsular fine particles comprising the olefinic polymer, of which the ratio (L/M) of the outer diameter (L) to the inner diameter (M) is 1.1 to 6.0, and the average diameter is 0.6 to 40 ?m.

Abstract: An asphalt-based sheet roofing material includes capsules on its upper surface. When struck, as by hailstones, the capsules break to release a film forming fluid that spreads over the surface to heal the damage created by the hailstones.

Abstract: A method that heat-expandable microspheres includes the use of a shell of thermoplastic resin and a non-fluorine blowing agent encapsulated therein having a boiling point not higher than the softening point of the thermoplastic resin. The method includes, a step of dispersing an oily mixture containing a polymerizable component, the blowing agent, and a polymerization initiator containing a peroxydicarbonate in an aqueous dispersing medium to polymerize the polymerizable component contained in the oily mixture. The resultant heat-expandable microsphres have a shell which is less apt to become thinner than its theoretical value, contain minimum amount of resin particle inside their shell, and have excellent heat-expanding performance.

Abstract: The present invention relates to a coarsely divided microcapsule preparation with particles whose particle sizes are in the range from 200 ?m to 5 cm, comprising microcapsules with a capsule core of latent heat storage material and a thermosetting polymer as capsule wall and one or more polymeric binders whose binder polymer has thermoplastic properties and film-forming properties under processing conditions, where the binder content, calculated as solid, is 1-30% by weight, based on the total weight of the coarsely divided microcapsule preparation.

Abstract: A process for preparing a perfume composition, the process having the steps of; (a) contacting a perfume ingredient with a molten material to form a pre-mix; (b) contacting the pre-mix with a first solid material to form a soft-solid intermediate high active perfume material; (c) solidifying the molten material to form a hardened-solid intermediate high active perfume material; (d) contacting the hardened-solid intermediate high active perfume intermediate material with a second solid material to form a perfume composition, wherein the ratio of the wt % amount of perfume ingredient present in the hardened-solid intermediate high active perfume material to the wt % amount of perfume ingredient present in the perfume composition is greater than 1.5:1.

Abstract: The invention provides an article comprising, a mesoporous silicate matrix, such as a particle, having one or more pores; and one or more releasable caps obstructing one or more of the pores. The articles are useful as delivery vehicles for encapsulated agents such as therapeutic agents, polynucleotides, polypeptides and the like.

Abstract: A W/O emulsion is produced from an aqueous solution containing a substance to be entrapped in a vesicle in a dissolved or suspended state and an oil phase containing an emulsifier; subsequently, the W/O emulsion is cooled to a temperature at which the aqueous solution of the W/O emulsion becomes a frozen particle and the oil phase maintains a liquid state, and the oil phase is removed; thereafter, an oil phase containing a vesicle constituent lipid is added to the frozen particle, and the obtained mixture is then stirred, so as to substitute the emulsifier on the surface of the frozen particle with the vesicle constituent lipid; and thereafter, an external Water phase is added to the frozen particle coated with a lipid membrane, so as to hydrate the lipid membrane by the external water phase. This process achieves a high entrapment yield of a desired substance while controlling desired physical properties such as particle diameter.

Abstract: An aqueous dispersion of polymeric particles and process for forming thereof is provided. The particles comprise a first polymer comprising, when dry, at least one void; and, substantially encapsulating the first polymer, at least one second polymer comprising, as polymerized units, at least one ethylenically unsaturated monomer.

Abstract: A production method for heat-expandable microspheres, which have high expanding ratio and are thermally expanded into hollow particulates having excellent repeated-compression durability, and application thereof are provided. The method produces heat-expandable microspheres a shell of thermoplastic resin and a blowing agent being encapsulated therein and having a boiling point not higher than the softening point of the thermoplastic resin.

Abstract: The invention described herein relates to a method of preparing microcapsules comprising a capsule core, a polymeric capsule wall and also, disposed on the outer surface of the capsule wall, a polyelectrolyte having an average molecular weight in the range from 500 g/mol to 10 million g/mol, the polymeric capsule wall being formed from specified monomers, where the microcapsules have an average particle size of 1.5-2.5 ?m and 90% of the particles have a particle size ?4 ?m, by microencapsulating a capsule core with a polymeric capsule wall and then contacting the polymeric capsule wall with one or more polyelectrolytes in water or an aqueous medium.

Abstract: A micronetwork made from microcapsules with or without nanomaterials and/or micromaterials such as microtubes, nanotubes and/or buckyballs; the micronetworks can be formulated to provide for unique properties such as reduction of crack propagation and/or corrosion.

Abstract: A decomposable thin film comprising a plurality of polyelectrolyte layers of alternating charge, wherein decomposition of the thin film is characterized by degradation of at least a portion of the polyelectrolyte layers.

Abstract: Hollow thermoexpandable particles or microspheres are provided that contain hydrocarbon blowing agents and have a shell polymer that can be softened at the onset of the expansion temperature and solidified at a higher temperature (thermoset) in an expanded state. Preferably, the microspheres have a shell of thermally expandable and thermally crosslinkable polymer and a hollow interior that contains a hydrocarbon liquid that boils at a temperature below the heat activated crosslinking temperature of the polymer shell. The crosslinking of the shell polymer during or after expansion, which is heat activated at an elevated temperature, can solidify the shell polymer and, then, maintain the expanded volume of the microspheres. The thermoexpandable thermoset polymer particles are useful in insulation, packaging, for making foam materials such as polyurethane or polyisocyanurate rigid foams.

Abstract: The present invention relates to a method for producing a porous resin particle having a functional group X, the method including: dissolving a radical polymerizable aromatic monovinyl monomer and a radical polymerizable aromatic divinyl monomer together with a polymerization initiator in an organic solvent to prepare a monomer solution, dispersing the monomer solution in water in the presence of a dispersion stabilizer to obtain a suspension polymerization reaction mixture, and performing a suspension copolymerization while adding, when 0 to 80% of the entire polymerization time of the suspension copolymerization is passed, a mercapto compound represented by the formula (I): HS—R—X??(I) in which R represents an alkylene group having a carbon number of 2 to 12, and the functional group X represents a functional group selected from a hydroxy group and a primary amino group, to the suspension polymerization reaction mixture; and the porous resin particle obtained by the method.

Abstract: A fireproof insulating foamed cementitious composition with thermal energy storage capacity is provided for use in producing wall insulation boards, fireproof claddings for steel structures, inner cores of fire resistant wall or door panels, and the like. The composition demonstrates improved energy efficiency in which phase change materials, such as microencapsulates, are used in conjunction with a cementitious mixture of calcined gypsum and hydraulic cement, lightweight aggregates, a polymer latex, and a foaming solution to create stable air bubbles inside the cementitious matrix. The calcined gypsum and the hydraulic cement are present in a weight ratio range from about 1:3 to about 3:1. The composition may further include reinforced fibers, surfactants, inorganic flame retardants, and other additives.

Abstract: The invention discloses a population of selected permeability microcapsule particles comprising an oil soluble or dispersible core material and a wall material at least partially surrounding the core material. The microcapsule wall material comprises the reaction product of a first composition in the presence of a second composition comprising an anionic emulsifier. The first composition comprises a reaction product of i) an oil soluble or dispersible amine with ii) a multifunctional acrylate or methacrylate monomer or oligomer, an oil soluble acid and an initiator. The anionic emulsifier comprises a water soluble or water dispersible acrylic acid alkyl acid copolymer, an optional initiator and an alkali or alkali salt. The reaction product of the first composition and second composition can result in the formation of a low permeability microcapsule wall. Optionally, one or both of the first composition initiator or water phase initiator is an energy-activated initiator, such as a UV initiator.

Abstract: The present invention teaches a cationically charged or neutral microcapsule particle comprising an oil soluble or dispersible core material and a wall material at least partially surrounding the core material, the microcapsule wall material comprising the reaction product of a first composition in the presence of a second composition comprising an emulsifier which is cationic or nonionic, the first composition comprising a reaction product of i) an oil soluble or dispersible amine with ii) a multifunctional acrylate or methacrylate monomer or oligomer, an oil soluble acid and an initiator. The cationic or nonionic emulsifier comprises a water soluble or water dispersible material and optionally a water phase initiator. The first composition initiator and the water phase initiator is an energy-activated initiator.

Abstract: Microcapsules possessing Lewis acid-Lewis base salt walls incorporate water-immiscible materials, such as N,N-diethyl-m-toluamide (DEET), as a core component. Such microcapsules, or similar microcapsules incorporating other core components, may be made by emulsifying a water-immiscible core component in an aqueous solution of one wall-forming reactant, such as the Lewis base, and then mixing that solution with the other wall-forming reactant, such as the Lewis acid. Various adjuvants may be included with the core component to contribute additional characteristics, such as enhancement of a controlled release characteristic or improved mechanical stability.

Abstract: A novel method of forming water in oil microcapsules is disclosed. According to the invention microcapsules are obtained by steps comprising dispersing an oil soluble amine modified polyfunctional polyvinyl monomer and an oil soluble bi- or polyfunctional vinyl monomer along with a thermal or UV free radical initiator (optionally included in one or both of the oil or water phases) and an organic acid into an internal phase oil; heating or UV exposing for a time (and temperature) sufficient to oligomerize the amine modified polyfunctional polyvinyl monomer and oil soluble bi- or polyfunctional vinyl monomer forming a pre-polymer. Thereafter the process involves adding to the oil phase oil a water phase comprising a dispersion in water of an anionic emulsifier (and optionally initiator), and adding an emulsifying agent. Emulsifying the water phase into the oil phase (W/O) is controlled through the quantity of water employed.

Abstract: The invention relates to polymer granules suitable as infill material for artificial turf structures wherein the granules have one or more hollow spaces, wherein each hollow space occupies at least 10% of the total volume of a polymer granule. The invention further relates to artificial turf structures comprising a backing sheet with an upper surface provided with fibres of a selected length, the fibres extending upwardly from the upper surface and an infill layer of hollow polymer granules or an e-layer comprising said hollow granules.

Abstract: The present invention includes a method for preparing polymer hydrogel spherical particles on a nanometer scale (nanogels). The method includes encapsulating hydrogel-forming components into liposomes, diluting the large unilamellar liposomes suspension to prevent polymerization outside the liposomes, and polymerizing the encapsulated hydrogel-forming components. The lipid bilayer may be solubilized with detergent. The phospholipid and detergent molecules and their micelles may then be removed by dialysis. The resulting nanogels may then be dried by evaporation in a temperature gradient. Poly(acrylamide), poly(N-isopropylacrylamide), and poly(N-isopropylacrylamide-co-1-vinylimidazole) hydrogel particles with a diameter from 30 to 300 nm were detected and characterized by dynamic light scattering technique. The solvent, temperature, pH, and ionic sensitivities of the nanogels were studied.

Abstract: The present invention relates to microencapsulated compositions of isothiazolone derivatives and other water insoluble biocides or antifouling agents. In particular, the present invention relates to microencapsulated 4,5 dichloro 2 n-octyl-3(2H)-isothiazolone (DCOIT), useful in marine antifouling coatings and paints.

Abstract: Microencapsulated delivery vehicles comprising an active agent are disclosed. In one embodiment, the microencapsulated delivery vehicles are heat delivery vehicles capable of generating heat upon activation. The microencapsulated heat delivery vehicles may be introduced into wet wipes such that, upon activation, the wet wipe solution is warmed resulting in a warm sensation on a user's skin. Any number of other active ingredients, such as cooling agents and biocides, can also be incorporated into a microencapsulated delivery vehicle.

Abstract: The present invention relates to a nanocapsule-type structure having an average particle diameter of 1 to 50 nm, said nanocapsule-type structure comprising an aqueous solution of a metal compound encapsulated in the inside thereof. Preferably, the nanocapsule-type structure is such that the nanocapsule structure is formed by self-organization of a surfactant in an organic solvent. This nanocapsule structure is in a nanometer size, and high in dispersibility even in a high-concentration region in an organic solvent, and does not undergo aggregation, and it is useful as a catalyst for a CVD method.

Abstract: The present invention relates to a microcapsular powder having a latent heat storage material as a capsule core and a capsule wall constructed of from 10% to 100% by weight of one or more C1-C24-alkyl esters of acrylic and/or methacrylic acid (monomers I), from 0% to 80% by weight of a water-insoluble or substantially water-insoluble bi- or polyfunctional monomer (monomers II), and from 0% to 90% by weight of other monomers (monomer III) all based on the total weight of the monomers, having an average particle size in the range of 150-400 ?m and having 80% by weight of particles ?90 ?m in diameter, to a process for its production and to its use in bindered building materials, textiles and dumped beds.

Abstract: Lipobeads (liposome-encapsulated hydrogels) combine properties of hydrogels and liposomes to create systems that are sensitive to environmental conditions and respond to changes in those conditions in a fast time scale. Lipobeads may be produced by polymerizing anchored or unanchored hydrogels within liposomes or by mixing anchored or unanchored hydrogels with liposomes. Giant lipobeads may be produced by shrinking unanchored nanogels in lipobeads and fusing the resulting lipobead aggregates, long-term aging of anchored or unanchored lipobeads, or mixing anchored or unanchored aggregated nanogels with liposomes. Poly(acrylamide), poly(N-isopropylacrylamide), and poly(N-isopropylacrylamide-co-1-vinylimidazole) lipobeads were produced and characterized.

Abstract: The hollow polymer particles of the present invention comprise a shell wall having for a main component thereof a copolymer obtained by polymerizing a monomer group (I) including a radical polymerizable water-soluble monomer (A) and a radical polymerizable water-insoluble monomer (B), and have a thickness of the shell wall of 5 to 80 nm. In addition, in the hollow polymer particle production process of the present invention, a monomer group (I) including a radical polymerizable water-soluble monomer (A) and a radical polymerizable water-insoluble monomer (B) is radical-polymerized using a polymerization initiator in an aqueous medium.

Abstract: A microcapsule comprising A) a core containing a hydrophobic liquid or wax, B) a polymeric shell comprising a) a polymer formed from a monomer mixture containing: i) 1 to 95% by weight of a hydrophobic mono functional ethylenically unsaturated monomer, ii) 5 to 99% by weight of a polyfunctional ethylenically unsaturated monomer, and iii) 0 to 60% by weight of other mono functional monomer, and b) a further hydrophobic polymer which is insoluble in the hydrophobic liquid or wax. The invention includes a process for the manufacture of particles and the use of particles in articles, such as fabrics, and coating compositions, especially for textiles.

Abstract: A process for producing a microparticulate hardening catalyst, comprising the steps of jetting a liquid composition containing epoxy resin hardening catalyst (A), monomer having an ethylenically unsaturated group (B) and photopolymerization initiator (C) through a minute nozzle into a gas so as to form microparticles; and while the microparticles are floating, irradiating the same with high-energy rays to thereby effect polymerization of the monomer having an ethylenically unsaturated group (B).

Abstract: The present invention provides methods for microencapsulation of active ingredients for topical application, whereby double-layer and triple-layer microcapsules are obtained. The microcapsules protect the active ingredients, maintain their original activity throughout processing, formulation and storage, and enable controlled release of the active ingredient only upon application onto the skin.