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Opis: Polyacrylic acid (PAA)-coated magnetic nanoparticles (MNP@PAA) were synthesized and evaluated as draw solutes in the forward osmosis (FO) process. MNP@PAA were synthesized by microwave irradiation and chemical co-precipitation from aqueous solutions of Fe2+ and Fe3+ salts. The results showed that the synthesized MNPs have spherical shapes of maghemite Fe2O3 and superparamagnetic properties, which allow draw solution (DS) recovery using an external magnetic field. Synthesized MNP, coated with PAA, yielded an osmotic pressure of ~12.8 bar at a 0.7% concentration, resulting in an initial water flux of 8.1 LMH. The MNP@PAA particles were captured by an external magnetic field, rinsed in ethanol, and re-concentrated as DS in repetitive FO experiments with deionized water as a feed solution (FS). The osmotic pressure of the re-concentrated DS was 4.1 bar at a 0.35% concentration, resulting in an initial water flux of 2.1 LMH. Taken together, the results show the feasibility of using MNP@PAA particles as draw solutes.
Ključne besede: magnetic nanoparticles, microwave synthesis, polyacrilic acid, osmotic pressure, draw solution, forward osmosis
Objavljeno v DKUM: 05.12.2023; Ogledov: 431; Prenosov: 16
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Opis: The problem of wastewater is increasing as we face tighter regulations in limiting parameters for discharge into sewers or surface waters. At the same time, the challenge is also how to upgrade existing technology and identify new appropriate technologies for purification of industrial wastewater for re-use. The optimal solution, which can give the appropriate quality of purified water at acceptable operating costs also is not straightforward. However, increasing environmental legislative demands combined with increased fresh water consumption can facilitate implementation of emerging technologies which at the current state are not fully mature. Forward Osmosis (FO) is one such recent achievement which is considered as a promising membrane process and potentially a sustainable alternative to reverse osmosis (RO) process for wastewater reclamation and sea/brackish water desalination. However, there are many limiting parameters (e.g. membrane fouling, draw solutions) in FO process that needs to be studied and improved. To reduce the membrane fouling in FO, many improvements were attempted, e.g. synthesis of different membrane materials, fabrication of membrane modules, membrane coating etc. One of the novelties in membrane development research field is biomimetic membranes incorporate in separation processes. They employ natural proteins known as AQPs (aqpourins) to regulate the flow of water, providing increased permeability and near-perfect solute rejection. Membrane surface characteristics were measured on virgin, used and cleane membrane in order to confirm the resistance to different types of industrial wastewater and sewage.
Ključne besede: biomimetic membrane, forward osmosis, industrial wastewater, reverse osmosis, textile wastewater, ultrafiltration, wastewater reuse
Objavljeno v DKUM: 25.07.2018; Ogledov: 2064; Prenosov: 125
Celotno besedilo (4,64 MB)

Opis: The hERG potassium channel is essential for repolarization of the cardiac action potential. Due to this vital function, absence of unintended and potentially life-threatening interactions with hERG is required for approval of new drugs. The structure of hERG is therefore one of the most sought-after. To provide purified hERG for structural studies and new hERG biomimetic platforms for detection of undesirable interactions, we have developed a hERG expression platform generating unprecedented amounts of purified and functional hERG channels. Full-length hERG, with or without a C-terminally fused green fluorescent protein (GFP) His 8-tag was produced from a codon-optimized hERG cDNA in Saccharomyces cerevisiae. Both constructs complemented the high potassium requirement of a knock-out Saccharomyces cerevisiae strain, indicating correct tetramer assembly in vivo. Functionality was further demonstrated by Astemizole binding to membrane embedded hERG-GFP-His 8 with a stoichiometry corresponding to tetramer assembly. The 156 kDa hERG-GFP protein accumulated to a membrane density of 1.6%. Fluorescence size exclusion chromatography of hERG-GFP-His 8 solubilized in Fos-Choline-12 supplemented with cholesteryl-hemisuccinate and Astemizole resulted in a monodisperse elution profile demonstrating a high quality of the hERG channels. hERG-GFP-His 8 purified by Ni-affinity chromatography maintained the ability to bind Astemizole with the correct stoichiometry indicating that the native, tetrameric structure was preserved. To our knowledge this is the first reported high-yield production and purification of full length, tetrameric and functional hERG. This significant breakthrough will be paramount in obtaining hERG crystal structures, and in establishment of new high-throughput hERG drug safety screening assays.
Ključne besede: potassium channel, membrane protein production, functional expression, cardiac action potential
Objavljeno v DKUM: 29.06.2017; Ogledov: 1505; Prenosov: 345
Celotno besedilo (2,85 MB)
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Opis: The discovery of selective water channel proteins-aquaporins-has prompted growing interest in using these proteins, as the building blocks for designing new types of membranes. However, as with any other new and potentially disruptive technology, barriers for successful market entry exist. One category includes customer-related barriers, which can be influenced to some extent. Another category includes market-technical-related barriers, which can be very difficult to overcome by an organization/company aiming at successfully introducing their innovation on the market%in particular if both the organization and the technology are at early stages. Often, one faces barriers from both these categories at the same time, which makes it necessary to gain insight of the particular market when introducing a new innovative product. In this review we present the basic concepts and discuss some of these barriers and challenges associated with introducing biomimetic aquaporin membranes. These include technical issues in membrane production and product testing. Then we discuss possible business models for introducing new technologies in general, followed by a presentation of beach-head market segments relevant for biomimetic aquaporin membranes.
Ključne besede: aquaporin membranes, biomimetic, commercialization, early stage technology
Objavljeno v DKUM: 21.06.2017; Ogledov: 1516; Prenosov: 339
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