| 1. |
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| 2. |
- Beer, Netta, et al.
(författare)
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A qualitative study on caretakers' perceived need of bed-nets after reduced malaria transmission in Zanzibar, Tanzania
- 2012
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Ingår i: BMC Public Health. - : Springer Science and Business Media LLC. - 1471-2458. ; 12, s. 606-
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Tidskriftsartikel (refereegranskat)abstract
- Background: The elimination of malaria in Zanzibar is highly dependent on sustained effective coverage of bed-nets to avoid malaria resurgence. The Health Belief Model (HBM) framework was used to explore the perceptions of malaria and bed-net use after a noticeable reduction in malaria incidence. Methods: Nineteen in-depth interviews were conducted with female and male caretakers of children under five in North A district, Zanzibar. Deductive content analysis was used to identify meaning units that were condensed, coded and assigned to pre-determined elements of the HBM. Results: Awareness of malaria among caretakers was high but the illness was now seen as easily curable and uncommon. In addition to the perceived advantage of providing protection against malaria, bed-nets were also thought to be useful for avoiding mosquito nuisance, especially during the rainy season when the malaria and mosquito burden is high. The discomfort of sleeping under a net during the hot season was the main barrier that interrupted consistent bed-net usage. The main cue to using a bed-net was high mosquito density, and children were prioritized when it came to bed-net usage. Caretakers had high perceived self-efficacy and did not find it difficult to use bed-nets. Indoor Residual Spraying (IRS), which was recognized as an additional means of mosquito prevention, was not identified as an alternative for bed-nets. A barrier to net ownership was the increasingly high cost of bed-nets. Conclusions: Despite the reduction in malaria incidence and the resulting low malaria risk perceptions among caretakers, the benefit of bed-nets as the most proficient protection against mosquito bites upholds their use. This, in combination with the perceived high self-efficacy of caretakers, supports bed-net usage, while seasonality interrupts consistent use. High effective coverage of bed-nets could be further improved by reinforcing the benefits of bed-nets, addressing the seasonal heat barrier by using nets with larger mesh sizes and ensuring high bed-net ownership rates through sustainable and affordable delivery mechanisms.
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| 3. |
- Campos, J, et al.
(författare)
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On the interaction between adsorbed layers of monoolein and the lipase action on the formed layers
- 2002
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Ingår i: Colloids and Surfaces B: Biointerfaces. - 1873-4367 .- 0927-7765. ; 26:1-2, s. 172-182
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Tidskriftsartikel (refereegranskat)abstract
- We used the Surface Force Apparatus (SFA) and ellipsometry techniques to study the interaction forces and the adsorption behavior of monoolein (MO), respectively. MO was adsorbed from water to a hydrophobised mica or silica surface. In addition the effect of added lipase, Thermomyces (Humicula) lanuginosa lipase (TLL), to an adsorbed layer of MO was investigated. The force versus distance curves between two MO covered surfaces feature a strong repulsive interaction beneath 400 A. The range of the repulsive force decreases, however, with the number of approaches. No adhesion was observed, provided that the surfaces were not taken to hydrophobic contact. The surface separation at MO-MO contact was determined to about 55 Angstrom This means a layer thickness of about 27 Angstrom, which is comparable to the thickness (25 Angstrom) determined by ellipsometry. The repulsive force may arise from compression of a cubic phase of MO. This phase are suggested to form between the surfaces when they approach close contact due to capillary induced phase separation (CIPS) from the saturated MO solution. The repulsive force changes significantly with time after addition of TLL (concentration of about 1 x 10(-8) M). In contrast to the force curves recorded before adding TLL, the surfaces do not seem to be completely covered with MO as we always observed an attractive force (inward jump) of similar range as was observed between pure OTE surfaces. Ellipsometry measurement of TLL action on MO covered hydrophobic surface reveals a significant and sharp decrease of the amounts adsorbed. Furthermore, the rate of decrease and reduction in adsorbed amount increased with TLL concentration. (C) 2002 Elsevier Science B.V. All rights. reserved.
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| 4. |
- Davidsson, K.O., et al.
(författare)
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Countermeasures against alkali-related problems during combustion of biomass in a circulating fluidized bed boiler
- 2008
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Ingår i: Chemical Engineering Science. - : Elsevier. - 0009-2509 .- 1873-4405. ; 63:21, s. 5314-5329
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of this work was to study different ways to mitigate alkali-related problems during combustion of biomass in circulating fluidized beds. Wood chips and wood pellets were fired together with straw pellets, while the tendency to agglomerate and form deposits was monitored. In addition to a reference case, a number of countermeasures were applied in related tests. Those were addition of elemental sulphur, ammonium sulphate and kaolin to a bed of silica sand, as well as use of olivine sand and blast-furnace slag as alternative bed materials. The agglomeration temperature, composition and structure of bed-ash samples were examined. The flue-gas composition, including gaseous alkali chlorides, was measured in the hot flue gases and in the stack. Particles in the flue gas were collected and analysed for size distribution and composition. Deposits were collected on a probe in hot flue gases and their amount and composition were analysed. Addition of kaolin was found to be the best method to counteract the agglomeration problem. The deposition problem is effectively counteracted with addition of ammonium sulphate, while kaolin is too expensive to be used commercially against deposits, and sulphur is less effective than ammonium sulphate.
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| 5. |
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| 6. |
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| 7. |
- Eskilsson, Anna, et al.
(författare)
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Distribution of microsomal prostaglandin E synthase-1 in the mouse brain
- 2014
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Ingår i: Journal of Comparative Neurology. - : John Wiley & Sons. - 0021-9967 .- 1096-9861. ; 522:14, s. 3229-3244
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Tidskriftsartikel (refereegranskat)abstract
- Previous studies in rats have demonstrated that microsomal prostaglandin E synthase-1 (mPGES-1) is induced in brain vascular cells that also express inducible cyclooxygenase-2, suggesting that such cells are the source of the increased PGE2 levels that are seen in the brain following peripheral immune stimulation, and that are associated with sickness responses such as fever, anorexia, and stress hormone release. However, while most of what is known about the functional role of mPGES-1 for these centrally evoked symptoms is based on studies on genetically modified mice, the cellular localization of mPGES-1 in the mouse brain has not been thoroughly determined. Here, using a newly developed antibody that specifically recognizes mouse mPGES-1 and dual-labeling for cell-specific markers, we report that mPGES-1 is constitutively expressed in the mouse brain, being present not only in brain endothelial cells, but also in several other cell types and structures, such as capillary-associated pericytes, astroglial cells, leptomeninges, and the choroid plexus. Regional differences were seen with particularly prominent labeling in autonomic relay structures such as the area postrema, the subfornical organ, the paraventricular hypothalamic nucleus, the arcuate nucleus, and the preoptic area. Following immune stimulation, mPGES-1 in brain endothelial cells, but not in other mPGES-1-positive cells, was coexpressed with cyclooxygenase-2, whereas there was no coexpression between mPGES-1 and cyclooxygenase-1. These data imply a widespread synthesis of PGE2 or other mPGES-1-dependent products in the mouse brain that may be related to inflammation-induced sickness symptom as well as other functions, such as blood flow regulation.
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| 8. |
- Eskilsson, K, et al.
(författare)
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DNA-surfactant complexes at solid surfaces
- 2001
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Ingår i: Langmuir. - 0743-7463 .- 1520-5827. ; 17, s. 1666-1669
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Tidskriftsartikel (refereegranskat)abstract
- In this work, we report on the adsorption of complexes between DNA of different molecular weight and a cationic surfactant, cetyltrimethylammonium bromide (CTAB), on hydrophobized and hydrophilic negatively charged silica surfaces as measured by ellipsometry. We will demonstrate how the adsorption is affected by the state of the DNA-surfactant complexes formed in bulk solution. High molecular weight DNA molecules, which condense (transform from coil to globule state) on addition of small amounts of cationic surfactants, do not adsorb on hydrophilic silica prior to phase separation. However, DNA-surfactant complexes formed from low molecular weight DNA were found to adsorb. For these complexes surfactants interact with DNA, without condensation of the DNA. Adsorbed DNA-surfactant complexes can easily be removed from the hydrophilic silica surface when replacing the bulk DNA-surfactant solution with pure salt solution. At the hydrophobic surface the DNA adsorbs without addition of cationic surfactant. However, with addition of a very low amount of surfactant, a rapid increase in adsorbed amount and a simultaneous decrease in adsorbed layer thickness are observed. This compaction of the adsorbed layer is to some extent reversible when replacing the bulk DNA-surfactant solution with pure salt solution.
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| 9. |
- Eskilsson, K, et al.
(författare)
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Effects of adsorption of low-molecular-weight triblock copolymers on interactions between hydrophobic surfaces in water
- 1999
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Ingår i: Langmuir. - 0743-7463 .- 1520-5827. ; 15, s. 3242-3249
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Tidskriftsartikel (refereegranskat)abstract
- In this work, we report on the interaction forces between hydrophobized silica surfaces immersed in polymer solutions. The polymers studied were a series of polyethylene oxide-polytetrahydrofuran-polyethylene oxide (PEO-PTHF-PEO) triblock copolymers and a polyethylene oxide homopolymer. The interaction forces were measured by the interfacial gauge technique. We show how the interactions depend on the adsorbed state of the copolymers, which in turn depends both on the copolymer concentration and the adsorption time. Above a critical surface coverage, the interaction between approaching surfaces was found to begin with a steric repulsion due to overlap of the adsorbed polymer layers. This repulsion increases as the distance between the surfaces was decreased. The energy-distance curve could, in this regime, be accounted for by the theory of grafted polymer brushes by Alexander-de Gennes. However, the interaction curves did not follow this prediction for small surface-to-surface distances. Instead, the repulsion stabilised at a more or less constant level with decreasing inter-surface separation. Finally, however, hard wall contact was established between the two surfaces. We infer that adsorbed copolymers to a large extent are expelled from the gap between the surfaces in this surface-to-surface distance range. The force needed to expel copolymers from the inter-surface gap was shown to be equal to the surface pressure at the solid-liquid interface. We also studied the influence of the rate of approach and separation of the surfaces on the energy-distance curves. The process of expelling polymers from the surface-to-surface gap was shown to depend on the velocity of the approaching surfaces and the surface coverage. For high approach rates and/or large surface coverage's, the lateral mobility of the polymers was generally observed to restrict the expulsion process of polymers from the gap. However, rapidly repeated force curves measured at constant rate in succession were found to be perfectly reproducible.
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| 10. |
- Eskilsson, K, et al.
(författare)
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Equilibrium and kinetic features of triblock copolymers at hydrophobic surfaces
- 1997
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Ingår i: Macromolecules. - 0024-9297 .- 1520-5835. ; 30, s. 6323-6332
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Tidskriftsartikel (refereegranskat)abstract
- The adsorption of a series of (ethylene oxide-tetrahydrofuran-ethylene oxide), EOn/2THFmEOn/2, triblock copolymers has been studied at the water/hydrophobic silica interface by time-resolved ellipsometry. The copolymers form monolayers with the middle tetrahydrofuran block anchoring at the surface and the ethylene oxide groups either anchoring at the surface or protruding into the aqueous phase. The degree of anchoring of the EO chains depends critically on the surface coverage. The copolymer isotherms are generally rather well described by the conventional Langmuir expression, and the plateau surface area per polymer molecule increases linearly with the molecular weight. However, the plateau thickness exhibits a more complex behavior. At low coverages, the adsorbed layer thickness is small, and both THF and EO chains form trains at the surface. As the surface coverage increases, however, the EO chains are increasingly forced away from the surface, and the mean thickness of the adsorbed layer exhibits a relatively strong linear dependence on the surface excess. At higher coverages, closer to the adsorption plateau, a weaker dependence is observed. The thickness increase is in this latter region due to the increasing steric repulsion between protruding EO chains. Outside the adsorbed layer, we also found support for the existence of a depletion layer. We show further that there are three regimes in the kinetics of adsorption. In the first (low surface coverage), the process is diffusion controlled and the rate is proportional to the concentration difference between the bulk solution and the subsurface located just outside the adsorbed layer. In the second regime (intermediate coverages and adsorption times), the kinetics are governed by the rate of displacement of anchored EO chains by THF chains of adsorbing copolymers. In the third regime (high surface coverages), the adsorption slows down markedly due to the energy barrier caused by presence of the relatively dense brush of adsorbed EO chains. In this regime, the surface excess varies proportionally with log t, which was also observed to be the case during the desorption process.
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| 11. |
- Eskilsson, K, et al.
(författare)
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Interaction between hydrophilic surfaces in triblock copolymer solution
- 1998
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Ingår i: Langmuir. - 0743-7463 .- 1520-5827. ; 14, s. 7287-7291
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Tidskriftsartikel (refereegranskat)abstract
- We report on the interactions between fused quarts surfaces immersed in solutions of low molecular weight nonionic homopolymers and triblock copolymers. The polymers studied were a polyethylene oxide homopolymer and a triblock copolymer of the type polyethylene oxide - polytetrahydrofuran - polyethylene oxide. The surface force measurements were done by the interfacial gauge technique. In water, a strong repulsive force was observed at short surface separations. Similar effects, previously attributed to the presence of hydration water, are due to electro-steric interactions imposed by partial stabilisation and formation of a gel layer on silica. Interestingly, this repulsive interaction was suppressed and not noticed when small amounts of polymers were adsorbed, or when water was substituted for ethanol as medium. Adsorbed polymers induce a long range steric repulsion of a quite different character. However, in solutions of PEO homo polymers, when the distance between the surfaces decreases, the repulsive interaction levels off. It remains more or less constant with decreasing surface-to-surface distance in this region. In this depletion range polymers are partly expelled from the gap between the surfaces. When the surfaces were separated after compression, an adhesive force was observed. This indicates that some adsorbed macromolecules remained in the gap after compression. For the PEO homopolymer the interaction both on approach and separation, showed a weak dependence on polymer concentration over a wide range. For the block copolymers, however, a stronger concentration dependence was observed. For instance, close to the surface aggregation concentration we observed an attractive interaction at some distances. This attraction is caused by bridging of surface micelles. It does not shows up at higher copolymer concentrations where the surface are fully covered by polymers. At low copolymer concentrations the copolymer aggregates are expelled to some extent from the gap between the surfaces at small surface-to surface distances. This depletion leads to a weak distance indifferent region with a small constant repulsion. At higher concentrations the interaction is purely repulsive at all surface-to surface distances, at both approach and separation. We studied also the role of solvent on interaction between surfaces in copolymer solutions. Adsorption of copolymers to silica from ethanol did not show long range interaction patterns but was sufficient to induce adhesion between the surfaces.
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| 12. |
- Eskilsson, K, et al.
(författare)
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Interfacial behaviour of triblock copolymers at hydrophilic surfaces
- 1998
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Ingår i: Macromolecules. - 0024-9297 .- 1520-5835. ; 31, s. 5075-5083
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Tidskriftsartikel (refereegranskat)abstract
- We report on the adsorption of a series of poly(ethylene oxide)-polytetrahydrofuran-poly(ethylene oxide) copolymers, EOn/2THFmEOn/2, at hydrophilic silica surfaces and relate our findings to the corresponding behavior at hydrophobic surfaces. The adsorption of these copolymers is similar to that of poly(ethylene oxide) homopolymers at low bulk concentrations. However, the copolymer adsorption increases strongly above a certain threshold concentration. This increase, which begins more than 1 order of magnitude below the critical micellar concentration (cmc), is related to the concomitant formation of micellar-like structures at the hydrophilic surfaces. We show in this work that a commercial (ethylene oxide-propylene oxide-ethylene oxide) triblock copolymer, Pluronic F127, exhibits a similar behavior at silica. Due to surface aggregation, much thicker layers are measured on silica than at the hydrophobic surface, where the adsorption results in the formation of a monolayer structure. The adsorbed amount and layer thickness measured on bare silica tend to decrease when the bulk concentration is raised above the cmc. We infer that this is due to changes of the molecular weight distribution and relative block sizes of the copolymers in the surface aggregates, i.e., a polydispersity effect. This study also covers some aspects of the adsorption and desorption kinetics exhibited by the copolymers at silica. As is common for adsorbing polymers, the concentration dependent adsorption process is generally observed to be much faster than the desorption process. The adsorption process is in parts diffusion controlled but overall to a complex to be fully analyzed. During adsorption from solutions with bulk concentrations exceeding the cmc, a clear overshoot of the surface excess is observed after intermediate adsorption times. Again, this is interpreted as being due to polydispersity. Finally, after an initial rapid desorption regime, the surface excess exhibits a logarithmic decay with time during desorption.
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| 13. |
- Eskilsson, K, et al.
(författare)
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Self-aggregation of triblock copolymers at the solid silica-water interface
- 1999
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Ingår i: Langmuir. - 0743-7463 .- 1520-5827. ; 15, s. 5150-5157
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Tidskriftsartikel (refereegranskat)abstract
- We report on the adsorption and surface aggregation behavior of triblock copoly(ethylene oxide-tetrahydrofuran-ethylene oxide) copolymers, EOn/2THFmEOn/2, at the silica-water interface. In this work, we have used both time-resolved fluorescence spectroscopy and atomic force microscopy to study the morphology of the adsorbed layers. We confirm previous suggestions that the copolymers self-assemble at the silica surface to form discrete micelle-like structures. The surface aggregation, however, starts at a much lower copolymer concentration than the corresponding micellization process in solution. The time-resolved fluorescence measurements reveal that the copolymer aggregates are smaller at the surface than those in bulk solution. The AFM measurements that were performed clearly confirm the existence of discrete micelle-like copolymer aggregates at the silica surface. An interesting result seen in the AFM surface topography images is that, for the high molecular weight copolymer, we observe no surface aggregates at some parts of surface. We believe this is related to the polydispersity of the copolymer. Single high molecular weight copolymers may effectively compete for surface area with surface aggregates formed by a copolymer fraction of lower molecular weight.
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| 14. |
- Eskilsson, K, et al.
(författare)
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Self-aggregation of triblock copolymers at the solid silica-water interface
- 1999
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Ingår i: LANGMUIR. - : AMER CHEMICAL SOC. - 0743-7463. ; 15:15, s. 5150-5157
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- We report on the adsorption and surface aggregation behavior of triblock copoly(ethylene oxide-tetrahydrofuran-ethylene oxide) copolymers, EOn/2THFmEOn/2, at the silica-water interface. In this work, we have used both time-resolved fluorescence spectrosco
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| 15. |
- Kapilashrami, A, et al.
(författare)
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Drying of oil-in-water emulsions on hydrophobic and hydrophilic substrates
- 2004
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Ingår i: Colloids and Surfaces A. - 0927-7757 .- 1873-4359. ; 233, s. 155-161
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Tidskriftsartikel (refereegranskat)abstract
- We have investigated the effect of the hydrophobic/hydrophilic character of the substrates on the drying behaviour of dilute silicone oil-in-water (o/w) emulsions by light microscopy and ellipsometry. The poly(dimethylsiloxane) (PDMS) emulsion droplets, which are stabilised by a triblock PEO/PPO/PEO copolymer, form a close-packed structure containing domains of hexagonally packed droplets on the hydrophilic substrate. We find that the hydrophilic substrate does not destabilise the emulsion droplets; the close-packed structures are very stable and coalesce very slowly only when most of the water has evaporated. This is supported by ellipsometry measurements, which showed that the emulsion droplets do not adsorb to the hydrophilic substrate. The hydrophobic substrate, on the other hand, destabilises the emulsion and we observed a significant increase in the coalescence rate. Ellipsometry measurements suggest that destabilisation is promoted by the strong interaction between the emulsion droplets and the hydrophobic substrate. We also find that the emulsion undergoes dewetting followed by a release of oil and rewetting of the substrate when the o/w emulsion film reaches a critical thickness on the hydrophobic substrate
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| 16. |
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| 17. |
- Kapilashrami, A, et al.
(författare)
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Ellipsometric studies of nonionic block copolymers adsorbed at the solid/water and oil/water interfaces
- 2003
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Ingår i: Colloids ad Surfaces a-Physicochemical and Engineering Aspects. ; 225:1-3, s. 181-192
-
Tidskriftsartikel (refereegranskat)abstract
- We report on the interfacial behaviour of a series of nonionic diblock copolymers at solid hydrophobic and hydrophilic surfaces/water and silicone oil/water interfaces, studied by ellipsometry. The polymers consist of a hydrophobic C-18 chain linked to a hydrophilic poly(ethylene oxide) (PEO), block varying from 50 to 250 U. The adsorption of these copolymers at low bulk concentrations was found to be dominated by the PEO block at all interfaces. At higher concentration the copolymer forms surface aggregates at the silica surface whereas we observe a gradual increase in the adsorbed layer thickness with increased surface excess at the solid hydrophobic surface, indicating a transition from a flat conformation to brush-like layer structure. The results indicate a similar evolution in adsorbed amount with concentration at the silicone oil/water interface as at the hydrophobic silica surface. The influence of the rheological proper ies of the interface on the adsorption of the diblock copolymer was investigated by comparing results from two silicon oils with different viscosities. The copolymers were found to have stronger affinity to a low viscosity (990 mPa s) silicone oil than to a higher viscosity (12 800 mPa s) silicone oil and the hydrophobised silica surface. At the silicone oil/water interface the adsorption of a commercial nonionic triblock copolymer was furthermore investigated and compared with the diblock copolymers. (C) 2003 Elsevier B.V. All rights reserved.
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| 18. |
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| 19. |
- Kapilashrami, A., et al.
(författare)
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Ellipsometric studies of nonionic copolymers adsorbed at the solid/water and oil/water interfaces
- 2003
-
Ingår i: Colloids and Surfaces A. - 0927-7757 .- 1873-4359. ; 225, s. 181-192
-
Tidskriftsartikel (refereegranskat)abstract
- We report on the interfacial behaviour of a series of nonionic diblock copolymers at solid hydrophobic and hydrophilic surfaces/water and silicone oil/water interfaces, studied by ellipsometry. The polymers consist of a hydrophobic C18 chain linked to a hydrophilic poly(ethylene oxide) (PEO), block varying from 50 to 250 U. The adsorption of these copolymers at low bulk concentrations was found to be dominated by the PEO block at all interfaces. At higher concentration the copolymer forms surface aggregates at the silica surface whereas we observe a gradual increase in the adsorbed layer thickness with increased surface excess at the solid hydrophobic surface, indicating a transition from a flat conformation to brush-like layer structure. The results indicate a similar evolution in adsorbed amount with concentration at the silicone oil/water interface as at the hydrophobic silica surface. The influence of the rheological properties of the interface on the adsorption of the diblock copolymer was investigated by comparing results from two silicon oils with different viscosities. The copolymers were found to have stronger affinity to a low viscosity (990 mPa s) silicone oil than to a higher viscosity (12800 mPa s) silicone oil and the hydrophobised silica surface. At the silicone oil/water interface the adsorption of a commercial nonionic triblock copolymer was furthermore investigated and compared with the diblock copolymers
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| 20. |
- Lindman, Björn, et al.
(författare)
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DNA-lipid systems. An amphiphile self-assembly and polymer-surfactant perspective
- 2002
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Ingår i: Lipid and Polymer-Lipid Systems. - Berlin, Heidelberg : Springer Berlin Heidelberg. - 0340-255X .- 1437-8027. - 9783540430018 ; 120, s. 52-63
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Konferensbidrag (refereegranskat)abstract
- The interaction between DNA and oppositely charged surfactants has been investigated by several techniques, like fluorescence microscopy, electron microscopy, phase diagram determination, and ellipsometry. The phase behaviour is more strongly associative than that in previously studied systems. A precipitate is formed for very low amounts of surfactant and DNA. DNA compaction is a general phenomenon in the presence of multivalent ions and positively charged surfaces; because of the high charge density there are strong attractive ion correlation effects. The interaction between DNA and catanionic mixtures (i.e., mixtures of cationic and anionic surfactants) was also investigated. We observed that DNA compacts and adsorbs onto the surface of positively charged vesicles and that the addition of anionic surfactant can release free DNA back into solution from a compact globular complex between DNA and cationic surfactant. Finally, we investigated DNA interactions with polycations, chitosans with different chain lengths, by fluorescence microscopy, in vivo transfections assays and cryogenic transmission electron microscopy. The general conclusion is that a chitosan effective in promoting compaction is also efficient in transfection.
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| 21. |
- Mogren, Sofia, et al.
(författare)
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Mast Cell Proteases Promote Diverse Effects on the Plasminogen Activation System and Wound Healing in A549 Alveolar Epithelial Cells
- 2022
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Ingår i: Cells. - : MDPI AG. - 2073-4409. ; 11:18
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Tidskriftsartikel (refereegranskat)abstract
- Tissue damage, epithelial alterations, and intraepithelial presence of mast cells (MCs) are characteristics of asthma pathogenesis. Increased alveolar infiltration of MC populations has also been identified as a feature of asthma and other chronic respiratory diseases. The asthma associated receptor, urokinase plasminogen activator receptor (uPAR), has been shown to regulate bronchial epithelial repair responses. However, the impact of MC tryptase and chymase on functional properties and expression of uPAR in alveolar epithelial cells have not been fully investigated. Alveolar epithelial cell migration and wound healing were investigated using holographic live cell imaging of A549 cells in a wound scratch model post stimulation with tryptase or chymase. The expression of uPAR was investigated on the protein and gene level from cellular supernatants and in bronchoalveolar lavage fluid fractions from allergic asthmatics. We found that tryptase improved wound healing capacity, cellular migration and membrane bound uPAR expression. Chymase reduced gap closure capacity, cellular migration and membrane bound uPAR expression but increased soluble uPAR release. Our data suggest a dual regulatory response from the MC proteases in events related to uPAR expression and wound healing which could be important features in asthmatic disease.
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| 22. |
- Samoshina, Yulia, et al.
(författare)
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Equilibrium aspects of polycation adsorption on silica surface: How the adsorbed layer responds to changes in bulk solution
- 2005
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Ingår i: Langmuir. - : American Chemical Society (ACS). - 0743-7463 .- 1520-5827. ; 21:13, s. 5872-5881
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Tidskriftsartikel (refereegranskat)abstract
- Adsorption of cationic high molecular weight polyacrylamides (CPAM) (M-w is about 800 kDa) with different fractions of cationic units tau = 0.09 and tau = 0.018 onto silica surface was studied over a wide range of pH (4-9) and KCl concentration (c(s) = 10(-3)-10(-1) M) by in-situ null ellipsometry. We discuss how the adsorbed layer depends on the bulk conditions as well as kinetically responds to changes in solution conditions. The adsorbed amount F of CPAM increases with pH for all studied electrolyte concentrations until a plateau F is reached at pH > 6. At low pH we observed an increase in adsorbed amount with electrolyte concentration. At high pH there is no remarkable influence of added salt on the values of the adsorbed amount. The thickness of adsorbed polymer layers, obtained by ellipsometry, increases with electrolyte concentration and decreases with pH. At low c(s) and high pH the polyelectrolyte adsorbs in a flat conformation. An overcompensation of the surface charge (charge reversal) by the adsorbed polyelectrolyte is observed at high c, and low pH. To reveal the reversibility of the polyelectrolyte adsorption with respect to the adsorbed amount and layer thickness, parameters such as polyelectrolyte concentration (cp), c(s) and pH were changed during the experiment. Generally, similar adsorbed layer properties were obtained independent of whether adsorption was obtained directly to initially bare surface or by changing pH, c(s) or the concentration of polyelectrolyte solution in the presence of a preadsorbed layer, provided that the coverage of the preadsorbed layer was low. Once a steady state of the measured parameters (Gamma, d) was reached, experimental conditions were restored to the original values and corresponding changes in Gamma and adsorbed layer thickness were recorded. For initially low surface coverage it was impossible to restore the layer properties, and in this case we always ended up with higher coverage than the initial values. For initial high surface coverage it was usually possible to restore the initial layer properties. Thus, we concluded that polyelectrolyte appears only partially reversible to changes in the solution conditions due the slow rearrangement process within the adsorbed layer.
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| 23. |
- Takook, Pegah, 1982, et al.
(författare)
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Prediction of tumor heatability in microwave hyperthermia applicators
- 2018
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Ingår i: IET Conference Publications. - : Institution of Engineering and Technology. ; 2018:CP741
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Konferensbidrag (refereegranskat)abstract
- In this paper, the heating efficiency of two hyperthermia applicators has been evaluated for the treatment of tumors in the brain. The effect of a high number of antennas and lower frequencies were investigated by employing one applicator with many antennas and one applicator with antennas operational in a lower frequency range. An investigation method was first used to find out the most difficult and easy places for heating inside the head. Given the applicator, patient model, and tumor position, the method is assessing whether or not the applicators are able to heat the tumor efficiently.
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| 24. |
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