759 results about "Semipermeable membranes" patented technology

Disclosed are esophageal anti-reflux valve prostheses, and tools and procedures for peroral implantation and extraction of the prostheses. The prostheses disclosed have a semipermeable membrane to allow retrograde passage of gas, magnets disposed at a distal end of the sleeve to facilitate closure, and an outwardly bendable array of spikes that are longitudinally aligned for peroral insertion and lockable into a radially outwardly deployed configuration to keep the prosthesis from dislocating after implantation. The implantation tool has inner and outer concentric tubes, the inner tube releasably threadably connected to the prosthesis, the outer tube reverse threaded with the inner tube to advance a distal headpiece to engage, deploy and lock the spikes into the deployed configuration. A vacuum assist can be used to help impact the lumen wall on the spikes. The extraction tool is similar to the implantation tool with an inner tube for threadably engaging the prosthesis, an outer tube with a distal crown with a plurality of shoes to unseat and unlock the spikes, and an overtube shield to receive the spikes and facilitate extraction of the prosthesis.

When forming a separating functional layer containing crosslinked polyamide, by carrying this out in the presence of 1) carboxylic acid ester with a total of 8 or more carbons, or 2) carboxylic acid, it is possible to provide a composite semipermeable membrane which, while still maintaining a high rejection rate, is more outstanding in its water permeability than hitherto.

A composite semipermeable membrane comprising a porous support membrane on which a separating functional polyamide layer resulting from the polycondensation reaction of polyfunctional aromatic amines with polyfunctional acid halides is formed, wherein the separating functional polyamide layer has carboxy groups, amino groups, phenolic hydroxyl groups, and azo groups, wherein XA, the ratio of the amino groups (molar equivalent of the amino groups / (molar equivalent of the azo groups+molar equivalent of the phenolic hydroxyl groups+molar equivalent of the amino groups)) on a feed water contact surface of the separating functional polyamide layer (an A surface), is in the range 0.5 or less, and XB, the ratio of the amino groups (molar equivalent of the amino groups / (molar equivalent of the azo groups+molar equivalent of the phenolic hydroxyl groups+molar equivalent of the amino groups)) on a permeate-side surface of the separating functional polyamide layer (a B surface), i.e., the opposite side to the A surface, is in the range of 0.5 to 1. The present invention provides a composite semipermeable membrane that achieves a balance between high solute removal properties and a high permeate flow rate and has high organic-solvent resistance, and a method for producing same.

A composite semipermeable membrane which satisfies the following relationship when seawater at 25° C. having a pH of 6.5, a boron concentration of 5 ppm and a TDS concentration of 3.5% by weight is permeated under an operation pressure of 5.5 MPa: Boron removal ratio (%)≧95−4×membrane permeation flow rate (m3 / m2·day).

A system which includes a separation element (11) employing semipermeable membrane material (17), which system is designed so that it can operate either in an RO mode to produce high quality water or in a PRO mode to generate power from two aqueous solutions of different salt concentrations. In a preferred embodiment, a rotary pressure transfer device (29) is included to transfer pressure from an outlet stream exiting the separation element to an inlet stream being supplied to the separation element.

The invention provides a process for producing a tubular membrane assembly comprising helically winding at least one strip of fibrous material on a mandrel to produce at least a single ply tubular support member for a semi-permeable membrane, characterized by passing the strip through a heated section of the mandrel during the helical winding thereof to flatten and smooth fibers protruding along the cross-sectional width of the strip, whereby a tube with a smooth inner bore along its entire length is formed.

Laser-induced phase-separation polymerization of a porous acrylate polymer is used for in-situ fabrication of dialysis membranes inside glass microchannels. A shaped 355 nm laser beam is used to produce a porous polymer membrane with a thickness of about 15 μm, which bonds to the glass microchannel and form a semi-permeable membrane. Differential permeation through a membrane formed with pentaerythritol triacrylate was observed and quantified by comparing the response of the membrane to fluorescein and fluorescently tagging 200 nm latex microspheres. Differential permeation was observed and quantified by comparing the response to rhodamine 560 and lactalbumin protein in a membrane formed with SPE-methylene bisacrylamide. The porous membranes illustrate the capability for the present technique to integrate sample cleanup into chip-based analysis systems.

Methods and materials for making complex, living, vascularized tissues for organ and tissue replacement, especially complex and / or thick structures, such as liver tissue is provided. Tissue lamina is made in a system comprising an apparatus having (a) a first mold or polymer scaffold, a semi-permeable membrane, and a second mold or polymer scaffold, wherein the semi-permeable membrane is disposed between the first and second molds or polymer scaffolds, wherein the first and second molds or polymer scaffolds have means defining microchannels positioned toward the semi-permeable membrane, wherein the first and second molds or polymer scaffolds are fastened together; and (b) animal cells. Methods for producing complex, three-dimensional tissues or organs from tissue lamina are also provided.

The osmotic devices of the present invention contain a unitary core comprising a salt of amantadine and an osmotic salt, wherein the two salts have an ion in common. The release rate of the amantadine is a sigmoidal release. The osmotic device includes a semipermeable membrane having a controlled porosity that can be adapted as needed to cooperate with the osmotic salt in providing a predetermined drug release profile. The osmotic salt need not be coated and it is in admixture with the amantadine salt. The osmotic device further includes a drug-containing coat external to the semipermeable membrane. The osmotic device can include one or more additional drugs in the core and / or the drug-containing coat.

A polyamide membrane comprising reaction product of an anhydrous solution comprising an anhydrous solvent, at least one polyfunctional secondary amine and a pre-polymer deposition catalyst; and an anhydrous, organic solvent solution comprising a polyfunctional aromatic amine-reactive reactant comprising one ring. A composite semipermeable membrane comprising the polyamide membrane on a porous support. A method of making a composite semipermeable membrane by coating a porous support with an anhydrous solution comprising an anhydrous solvent, a polyfunctional secondary amine and a pre-polymer deposition catalyst, to form an activated pre-polymer layer on the porous support and contacting the activated pre-polymer layer with an anhydrous, organic solvent solution comprising a polyfunctional amine-reactive reactant to interfacially condense the amine-reactive reactant with the polyfunctional secondary amine, thereby forming a cross-linked, interfacial polyamide layer on the porous support. A method of impregnating a composite semipermeable membrane with nanoparticles selected from heavy metals and / or oxides of heavy metals.

Methods and materials for making complex, living, vascularized tissues for organ and tissue replacement, especially complex and / or thick structures, such as liver tissue is provided. Tissue lamina is made in a system comprising an apparatus having (a) a first mold or polymer scaffold, a semi-permeable membrane, and a second mold or polymer scaffold, wherein the semi-permeable membrane is disposed between the first and second molds or polymer scaffolds, wherein the first and second molds or polymer scaffolds have means defining microchannels positioned toward the semi-permeable membrane, wherein the first and second molds or polymer scaffolds are fastened together; and (b) animal cells. Methods for producing complex, three-dimensional tissues or organs from tissue lamina are also provided.

The present invention provides a simple and improved rupturing controlled release device that is capable of providing a controlled release of active agent contained in the core first through a preformed passageway and then through an in situ formed second passageway into an environment of use in a standardized release profile manner. The rupturing controlled release device comprises a core comprising at least one drug and at least one osmopolymer, a semipermeable membrane enclosing the core and having at least one preformed passageway there through, wherein the semipermeable membrane ruptures during use to form a second passageway in the semipermeable membrane at a location spaced away from the preformed passageway, and a release-controlling subcoat between the core and the semipermeable membrane.

A metabolite monitoring system comprising a microdialysis probe including a semi-permeable membrane and a probe flow path passing from an inlet through a sensing volume adjacent to said semi-permeable membrane to an outlet, a fluid delivery device for delivering dialysate to said inlet; and a metabolite monitoring system associated with said outlet for monitoring a concentration of at least one metabolite in said dialysate from said microdialysis probe, wherein said fluid delivery device is configured to deliver a pulsed flow of said dialysate to said inlet.

The osmotic devices of the present invention contain a unitary core comprising a salt of amantadine and an osmotic salt, wherein the two salts have an ion in common. The release rate of the amantadine is modified from a first order release profile to a zero order, pseudo-zero order or sigmoidal release profile by increasing the amount of the osmotic salt in the core of the device. The osmotic device includes a semipermeable membrane having a controlled porosity that can be adapted as needed to cooperate with the osmotic salt in providing a predetermined drug release profile. The osmotic salt need not be coated and it is in admixture with the amantadine salt.

Disclosed is a method of forming graphene. A graphite positive electrode (or positive electrode together with graphite material) wrapped in a semipermeable membrane and a negative electrode are dipped in an acidic electrolyte to conduct an electrolysis process. As such, a first graphene oxide having a size larger than a pore size of the semipermeable membrane is exfoliated from the graphite positive electrode (or the graphite material). The electrolysis process is continuously conducted until a second graphene oxide is exfoliated from the first graphene oxide, wherein the second graphene oxide has a size which is smaller than the pore size of the semipermeable membrane to penetrate through the semipermeable membrane. The second graphene oxide diffused into the acidic electrolyte outside of the semipermeable membrane is collected. Finally, the collected second graphene oxide is chemically reduced to obtain a graphene.

An inkjet assembly comprising a vented ink reservoir for containing a liquid ink therein, the vented ink reservoir defining an internal volume occupied at least in part by a semipermeable membrane in fluid communication with a vent that automatically adjusts for pressure differentials by enabling gaseous diffusion between an environment external to the vented ink reservoir and the internal volume of the vented ink reservoir, while inhibiting liquid diffusion therethrough. A method is also disclosed for mounting the semipermeable membrane to at least one of an ink reservoir cap and an ink tank.