Asymmetric Membrane
Mostrando 13-24 de 166 artigos, teses e dissertações.
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13. Preparo e caracterização de membranas de quitosana modificadas com poli (ácido acrílico)
The aim of this study was to generate an asymmetric biocompactible and biodegradable chitosan membrane modified by the contact with a poly(acrylic acid) solution at one of its sides at room temperature and 60◦C. The pure chitosan membrane, as well as the ones treated with poly(acrylic acid) were characterized by infrared spectroscopy (FTIRATR) at
Publicado em: 2006
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14. Preparação, caracterização e aplicação de membranas de poli (fluoreto de vinilideno) para a redução de cor de efluente textil modelo
The textile industry processes deal with many different materiais being responsible for a large volume of potential pollutant streams, mainly due to losses of dyes occurring during the dyeing process of the fibers, which are discarded in the effluent. Membrane separation processes are considered potential good new alternatives for the treatment of textile ef
Publicado em: 2004
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15. DifusÃo e transporte na presenÃa de macromolÃculas. Imagens e espectroscopia por RMN
The electronic Overhauser effect was employed to enhance nuclear magnetic resonance images obtained in a magnetic eld of only 16 mT. Despite the weak magnetic eld, the technique can reveal, in some systems, various aspects of ionic transport and kinetics apparently not observed in conventional high-eld magnetic resonance imaging. We employed Overhauser imagi
Publicado em: 2004
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16. Preparação, caracterização e aplicação de membranas polimericas microporosas assimetricas
This work starts with the preparation of asymmetric microporous polymeric membranes through phase inversion technique by immersion-coagulation in the presence of a non-solvent. The poly (vinylidene fluoride)-PVDF was used pure or blended with lithium chloride and one of the following polymeric additives: poly (vinyl acetate)-PVAc or poly (ethylene glycol)-PE
Publicado em: 2002
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17. Pervaporação pressurizada
This thesis reports on pure liquid and solution pervaporation experiments, in which the feed is kept at 0,3 to 1,4 MPa pressure. Silicone rubber flat membranes made of RTV resin were used throughout. The preparation of a new type of silicone membranes displaying an asymmetric structure is also described. Pervaporation experiments were performed using a steel
Publicado em: 1991
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18. Identification of a functional role for lipid asymmetry in biological membranes: Phosphatidylserine-skeletal protein interactions modulate membrane stability
Asymmetric distribution of phospholipids is ubiquitous in the plasma membranes of many eukaryotic cells. The majority of the aminophospholipids are located in the inner leaflet whereas the cholinephospholipids are localized predominantly in the outer leaflet. Several functional roles for asymmetric phospholipid distribution in plasma membranes have been sugg
The National Academy of Sciences.
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19. Asymmetric distribution of the apical plasma membrane during neurogenic divisions of mammalian neuroepithelial cells
At the onset of neurogenesis in the mammalian central nervous system, neuroepithelial cells switch from symmetric, proliferative to asymmetric, neurogenic divisions. In analogy to the asymmetric division of Drosophila neuroblasts, this switch of mammalian neuroepithelial cells is thought to involve a change in cleavage plane orientation from perpendicular (v
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20. The N terminus of the Drosophila Numb protein directs membrane association and actin-dependent asymmetric localization
Drosophila Numb is a membrane associated protein of 557 amino acids (aa) that localizes asymmetrically into a cortical crescent in mitotic neural precursor cells and segregates into one of the daughter cells, where it is required for correct cell fate specification. We demonstrate here that asymmetric localization but not membrane localization of Numb in Dro
The National Academy of Sciences of the USA.
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21. Osmotic flow through asymmetric membrane: A means for controlled delivery of drugs with varying solubility
A nondisintegrating, controlled release, asymmetric membrane capsular system of flurbiprofen was developed and evaluated for controlled release of the drug to overcome some of its side effects. Asymmetric membrane capsules were prepared using fabricated glass mold pins by phase inversion process. The effect of different formulation variables was studied base
Springer-Verlag.
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22. Membrane phospholipid asymmetry as a determinant of erythrocyte recognition by macrophages.
To assess the role of transbilayer phospholipid distribution in the recognition and phagocytosis of erythrocytes by macrophages, human erythrocytes with either a symmetric or asymmetric distribution of membrane phospholipids were prepared by hypotonic hemolysis and then incubated with cultures of human monocyte-derived macrophages. Erythrocytes with an abnor
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23. Asymmetric budding of viruses in epithelial monlayers: a model system for study of epithelial polarity.
Infection of two different lines of polarized epithelial cells grown as monolayers with several types of enveloped viruses results, for each virus type, in a characteristic asymmetric budding of virions. Influenza virus (WSN strain), simian virus 5, and Sendai virus bud exclusively from the free (apical) surface of the cells, while vesicular stomatitis virus
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24. Selective and asymmetric molecular transport across electroporated cell membranes.
Transport of a divalent cation (Ca2+) and three DNA indicators [ethidium bromide (EB), propidium iodide (PI), and ethidium homodimer (EthD-1)] across electroporated membranes of several mammalian cell lines was found to be selective and asymmetrical. In low salt medium, Ca2+ and EB were preferentially transported across the anodefacing cell membrane while PI