Processing of Visual Speech Cues in Speech-in-Noise Comprehension Depends on Working Memory Capacity and Enhances Neural Speech Tracking in Older Adults With Hearing Impairment.

Comprehending speech in noise (SiN) poses a challenge for older hearing-impaired listeners, requiring auditory and working memory resources. Visual speech cues provide additional sensory information supporting speech understanding, while the extent of such visual benefit is characterized by large variability, which might be accounted for by individual differences in working memory capacity (WMC). In the current study, we investigated behavioral and neurofunctional (i.

Activation of fibroblast metabolism in a dermal and skin equivalent model: a screening test for activity of peptides.

Skin firmness, elasticity and tone are gradually lost with age. These changes originate in the dermis and correspond to a decrease in the ability of cells, particularly the fibroblasts, to regenerate the molecules which make up the extracellular matrix. Skin ageing is also characterized by a reduction of the epidermal thickness and by a flattening of the basal membrane.

A skin equivalent model for cosmetological trials: an in vitro efficacy study of a new biopeptide.

The European Community directive, imposing that effects claimed for cosmetic actives must be validated using non-animal procedures, has stimulated the use of in vitro models for pharmacotoxicological trials. In this paper, an efficacy study of a new biopeptide, a hydrolysate obtained by fermentation of milk proteins, was performed using an in vitro skin equivalent (SE). This SE is obtained by seeding normal human keratinocytes onto a dermal equivalent comprising a collagen-glycosaminoglycan(GAG)-chitosan porous matrix populated by normal human fibroblasts, which neosynthesize their own extracellular matrix (ECM).

Cytocompatibility of calf pericardium treated by glutaraldehyde and by the acyl azide methods in an organotypic culture model.

Glutaraldehyde (GTA) is used to cross-link collagen-based biomaterials, but these materials are often cytotoxic. In order to overcome this problem, we have proposed the use of the acyl azide methods with either hydrazine or diphenylphosphoryl azide (DPPA) as reagents. In this paper we determine the cytocompatibility of acyl azide- and GTA-treated pericardium in vitro, by an organotypic chick aorta culture technique developed for the evaluation of the propensity of vascular cells (both endothelial and smooth muscle cells) to migrate and grow on the surface of biomaterials.

Use of diphenylphosphorylazide for cross-linking collagen-based biomaterials.

Cross-linking of collagen-based biomaterials increases their strength and persistence in vivo. Recently, we described an efficient cross-linking process via the formation of acyl azide groups on methylated carboxyl groups of collagen using hydrazine and nitrous acid (referred to here as the hydrazine method). In this report, we propose a simpler, faster way to prepare acyl azide groups and to cross-link collagen-based biomaterials, using diphenylphosphorylazide (DPPA) as a reagent.