| 1. |
- Dimitrevski, K., et al.
(författare)
-
Analysis of stable self-trapping of laser beams in cubic-quintic nonlinear media
- 1998
-
Ingår i: Physics Letters A. - : Elsevier. - 0375-9601 .- 1873-2429. ; 248:5-6, s. 369-376
-
Tidskriftsartikel (refereegranskat)abstract
- A numerical and analytical analysis of two-dimensional laser beam propagation in cubic-quintic nonlinear optical media demonstrates the existence of stable stationary radially symmetric modes. By means of a variational method, involving super-Gaussian trial functions and Ritz optimization, approximate stationary solutions are obtained, showing very good agreement with numerical results, even in the strongly non-linear, almost saturated, regime. The stability of the stationary modes are verified by analytical analysis and by direct numerical simulations.
|
|
| 2. |
- Eckardt, Johanna, et al.
(författare)
-
Long-term frozen storage of wheat bread and dough : Effect of time, temperature and fibre on sensory quality, microstructure and state of water
- 2013
-
Ingår i: Journal of Cereal Science. - : Elsevier BV. - 0733-5210 .- 1095-9963. ; 57:1, s. 125-133
-
Tidskriftsartikel (refereegranskat)abstract
- The objective of this study was to determine effect of storage time, storage temperature and addition of fibre on sensory quality, state of water, microstructure and texture of bread and dough. Samples with and without fibre, were stored frozen for 2, 3.5 and 6 months at temperatures of -19, -16 and -8 °C as dough and bread. Sensory quality was evaluated by a trained analytical panel. Microstructure was analysed by light microscopy. Texture measurements were performed on bread, and the state of water was measured by differential scanning calorimetry. Bread without fibre stored as dough at -19 °C was the sample most like freshly baked bread. Sensory evaluation also confirmed that quality of the final bread was improved if samples were stored as dough compared to stored as bread. The microstructure had larger gaps between the starch and gluten phases when stored at warmer temperatures, due to retrogradation of starch, dehydration of gluten and water migration. DSC measurements showed that bread stored at -19 °C gained extra amount of freezable water, but lost ice after storage at -8 °C. Texture measurements showed that firmness increased with extended storage time. Bread stored at -8 °C had lowest quality in all measurements.
|
|
| 3. |
- Persson, Eva M., et al.
(författare)
-
Is there an effect of food on the biliary secretion of cyclosporine and three in vivo formed metabolites in a porcine model?
- 2007
-
Ingår i: Journal of Drug Delivery Science and Technology. - 1773-2247. ; 17:4, s. 253-258
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to investigate the effect of lipids and P-glycoprotein (P-gp) inhibition on the biliary secretion of cyclosporine (CsA) and in vivo formed metabolites in pigs. A parallel group design including 12 pigs in four groups and a combined single-pass intestinal perfusion and bile collection method was employed. CsA was perfused through the jejunum in an isotonic fluid alone and with verapamil or lipids added. The study showed that there was no difference between the administration groups, except for the fraction of the absorbed dose that was excreted in bile was twice as high when CsA was administered together with lipids. In conclusion, CsA is excreted via the biliary route in pigs without any significant involvement of P-gp. Concomitant food-intake could increase the secretion to the bile, presumably by prolonged associations between the CsA and the lipid species.
|
|
| 4. |
- Öhgren, Camilla, et al.
(författare)
-
Surface-directed structure formation of β-lactoglobulin inside droplets
- 2011
-
Ingår i: Biomacromolecules. - : American Chemical Society (ACS). - 1525-7797 .- 1526-4602. ; 12:6, s. 2235-2242
-
Tidskriftsartikel (refereegranskat)abstract
- The morphology of β-lactoglobulin structures inside droplets was studied during aggregation and gelation using confocal laser scanning microscopy (CLSM) equipped with a temperature stage and transmission electron microscopy (TEM). The results showed that there is a strong driving force for the protein to move to the interface between oil and water in the droplet, and the β-lactoglobulin formed a dense shell around the droplet built up from the inside of the droplets. Less protein was found inside the droplets. The longer the β-lactoglobulin was allowed to aggregate prior to gel formation, the larger the part of the protein went to the interface, resulting in a thicker shell and very little material being left inside the droplets. The droplets were easily deformed because no network stabilizes them. When 0.5% emulsifier, polyglycerol polyresinoleat (PGPR), was added to the oil phase, the β-lactoglobulin was situated both inside the droplets and at the interface between the droplets and the oil phase; when 2% PGPR was added, the β-lactoglobulin structure was concentrated to the inside of the droplets. The possibility to use the different morphological structures of β-lactoglobulin in droplets to control the diffusion rate through a β-lactoglobulin network was evaluated by fluorescence recovery after photobleaching (FRAP). The results show differences in the diffusion rate due to heterogeneities in the structure: the diffusion of a large water-soluble molecule, FITC-dextran, in a dense particulate gel was 1/4 of the diffusion rate in a more open particulate β-lactoglobulin gel in which the diffusion rate was similar to that in pure water.
|
|
