Search results for "swelling"
showing 10 items of 192 documents
Influence of brine concentration on swelling pressure of pork meat throughout salting.
2009
Abstract The influence of sodium chloride on the water holding capacity of meat is well known and described in literature. An increase in water holding capacity is associated with an increase in the swelling pressure in the protein matrix. A novel device was used to measure the swelling pressure during brine salting of muscle cylinders (40 × 50 mm), in different NaCl brine concentrations (2.5 to 25%) over 6 days at 4 °C. Changes in meat composition, weight and height of non-constrained control samples were also measured. The aim of this work was to prove the feasibility of using the developed device in order to quantify the influence of the brine concentration on the magnitude of the swelli…
Agarose/κ-carrageenan-based hydrogel film enriched with natural plant extracts for the treatment of cutaneous wounds.
2020
Abstract Hydrogels for complex and chronic wound dressings must be conformable, absorb and retain wound exudates and maintain hydration. They can incorporate and release bioactive molecules that can accelerate the healing process. Wound dressings have to be in contact with the wound and epidermis, even for long periods, without causing adverse effects. Hydrogel dressing formulations based on biopolymers derived from terrestrial or marine flora can be relatively inexpensive and well tolerated. In the present article hydrogel films composed by agarose (1.0 wt%), κ-carrageenan at three different concentrations (0.5, 1.0 and 1.5 wt%) and glycerol (3.0 wt%) were prepared without recourse to cros…
Increased Stability of Rubber-Modified Asphalt Mixtures to Swelling, Expansion and Rebound Effect during Post-Compaction
2017
The application of bituminous mixtures modified with rubber from scrap-tires require attention and care during mixing and compaction. Rubber modifies the properties because it reacts in the internal structure of bitumen at high temperatures changing the performance of the mixture (interaction process of solvents with binder-rubber aggregate). The main change is the increasing of the viscosity and elasticity of the binder due to the larger sizes of the rubber particles by dry process but, this positive effect is counteracted by short mixing times, compared to wet technology, and due to the transport processes, curing time and post-compaction of the mixtures. Therefore, negative effects as sw…
Aloin delivery on buccal mucosa: ex vivo studies and design of a new locoregional dosing system
2014
Context: Chemoprevention of potential malignant disorders or cancerous lesions that affect oral mucosae requires extended duration of treatment. Locoregional delivery of natural products could represent a promising strategy for this purpose. Objective: To investigate the aptitude of aloin to permeate through, or accumulate in, the buccal mucosa and to develop a new prolonged oro-mucosal drug delivery system. Materials and Methods: Permeation/accumulation of aloin from Curacao Aloe (containing 50% barbaloin) was evaluated ex vivo, using porcine buccal mucosa as the most useful model to simulate human epithelium. Oro-mucosal matrix tablets were prepared by dispersing aloin (10% w/w) in Eudrag…
In vitro study of N-succinyl chitosan for targeted delivery of 5-aminosalicylic acid to colon
2011
In vitro study on N-succinyl chitosan and chitosan (control) matrices for selective colon delivery of 5-aminosalicylic acid is described. Matrices containing β-cyclodextrin were also prepared. As shown by DSC analyses, the drug was successfully loaded into the matrices reaching up to 95% entrapment efficiency. Swelling and drug release were studied at pH 1.2, pH 7.4, and in a pH gradient medium to simulate the gastro-intestinal transit. Main result of this study was a higher capability of N-succinyl chitosan alone to better control drug release in the simulated gastro-intestinal transit: N-succinyl chitosan gave the lowest release in acid medium (≅15%) and the highest in alkaline environmen…
Do female leaf beetles Galerucella nymphaeae choose their mates and does it matter?
1998
The role of active female choice in sexual selection is frequently difficult to ascertain, and this is particularly the case for many insect species. Also, it is uncertain whether choosing between males would affect offspring viability. We designed an experiment to investigate the presence of female choice in a Coleoptera species (Galerucella nymphaeae). We also estimated whether mate choice would have any effect on offspring performance. Females were first placed with two males in a test arena to see which of the males copulated with the virgin female, and how quickly. Subsequently the loser male was offered a new virgin female to test for any change in latency time until mating. The two-m…
Sorption Equilibria of Ethanol on Cork
2013
International audience; We report here for the first time a thermodynamic study of gaseous ethanol sorption on raw cork powder and plate. Our study aims at a better understanding of the reactivity of this material when used as a stopper under enological conditions, thus in close contact with a hydroethanolic solution, wine. Sorption−desorption isotherms were accurately measured by thermogravimetry at 298 K in a large range of relative pressures. Sorption enthalpies were determined by calorimetry as a function of loading. Sorption−desorption isotherms exhibit a hysteresis loop probably due to the swelling of the material and the absorption of ethanol. Surprisingly, the sorption enthalpy of e…
Equilibrium swelling properties of polyampholytic hydrogels
1996
The role of counter ions and ion dissociation in establishing the equilibrium swelling of balanced and unbalanced polyampholytic hydrogels has been investigated experimentally and theoretically. The swelling dependence on both the net charge offset and the external bath salt concentration has been examined using an acrylamide based polyampholytic hydrogels. By careful consideration of the swelling kinetics, we illustrate the effects of ion dissociation equilibria and counter ion shielding in polyampholytic hydrogels near their balance point where both polyelectrolyte and polyampholyte effects are present. The theory considers a Flory type swelling model where the Coulombic interactions betw…
Swellable microparticles containing Suprofen: evaluation of in vitro release and photochemical behaviour
1998
Suprofen, an anti-inflammatory drug was incorporated in polymer networks based on biocompatible macromolecules, such as alpha,beta-polyasparthydrazide (PAHy) and alpha,beta-poly(N-hydroxyethyl)-DL-aspartamide (PHEA) crosslinked by glutaraldehyde or gamma-rays, respectively. Swelling tests carried out in aqueous media showed that pH value affects the swelling degree of the prepared hydrogels. In vitro release tests were performed in simulated gastrointestinal fluids (pH 1/6.8) using the pH variation method and in phosphate-buffered saline, pH 7.4. Experimental data indicated that Suprofen was released in a sustained way both from PAHy and PHEA microparticles. Further, incorporation of Suprof…
Foreign body granulomatous reactions to cosmetic fillers
2012
Introduction: The use of different facial cosmetic fillers has increased in recent years. The introduction of apparently inert substances in the epidermis can give rise to foreign body granulomatous reactions. Objetives: A literature review is made of the foreign body granulomatous reactions to cosmetic fillers. Material and Methods: A PubMed-Medline search was made using the following keywords: “granulomatous reactions”, “foreign body reactions”, “esthetic fillers”, “cosmetic fillers”. The search was limited to articles published in English and Spanish during the last 10 years. A total of 22 articles were reviewed. Results: A great variety of substances have been found to give rise to fore…