[Body adiposity and abdominal muscle resistance in young people with Down syndrome]. / Adiposidad corporal y resistencia muscular abdominal en jóvenes con síndrome de Down.

OBJECTIVE: to verify the relationship between abdominal muscle endurance and the level of body fat, measured through the waist-to-height ratio, in young people with Down syndrome (DS). SUBJECT AND METHOD: A comparative descriptive study was carried out in 115 young people with DS (n = 65 men and n = 50 women) aged between 10 and 18 years, from the Maule Region. Age, weight, height, and waist circumference were evaluated. Body mass index (BMI) and waist-to-height ratio (WHtR) were calculated. The abdominal muscle endurance test (AME) was evaluated in 60 seconds and clas sified into two categories (low AME and acceptable AME). RESULTS: Subjects of both sexes classified with adequate levels of AME showed lower WHtR and BMI values (p < 0.05), while those classified with low levels of AME showed higher values of WHtR and BMI (p < 0.05). The correlations between adiposity and AME were negative and ranged in both sexes from r = 0.20 to 0.25, p < 0.05. Conclu sion: The study showed that young people of both sexes with DS classified with adequate levels of AME, presented decreased values of WHtR.

Stitching together a nm thick peptide-based semiconductor sheet using UV light.

Langmuir monolayer allows for a two-dimensional nano-scale organization of amphiphilic molecules. We have adapted this technique to measure lateral and transverse conductivity in confined peptide nanosheets for the first time. We reported that two retro-isomers amphipathic peptides form stable monolayers showing a semiconductor-like behavior. Both peptides exhibit the same hydrophobicity and surface stability. They differ in the lateral conductivity and current-voltage due to the asymmetric peptide bond backbone orientation at the interface. Both peptides contain several tyrosines allowing the lateral crosslinking in neighboring molecules induced by UVB. UVB-light induces changes in the lateral conductivity and current-voltage behavior as well as monolayer heterogeneity monitored by Brewster Angle Microscopy. The semiconductor properties depend on the peptide bond backbone orientation and tyrosine crosslinking. Our results indicate that one may design extended nano-sheets with particular electric properties, reminiscent of semiconductors. We propose to exploit such properties for biosensing and neural interfaces.