Visuo-attentional correlates of Autism Spectrum Disorder (ASD) in children with Down syndrome: A comparative study with children with idiopathic ASD.

BACKGROUND: Children with Down syndrome (DS) are at increased likelihood of Autism Spectrum Disorder (ASD) relative to the general population. To better understand the nature of this comorbidity, we examined the visuo-attentional processes associated with autistic trait expression in children with DS, focusing specifically on attentional disengagement and visual search performance. METHOD: We collected eye-tracking data from children with DS (n = 15) and children with idiopathic ASD (iASD, n = 16) matched according to chronological age. Seven children with DS had a formal clinical diagnosis of ASD (DS+ASD). RESULTS: In children with iASD, but not DS, higher autistic trait levels were associated with decreased temporal facilitation on a gap-overlap task, implying increased visuospatial orienting efficiency. In all cases, higher autistic trait levels were associated with improved visual search performance according to decreased target detection latency. On a visual search task, children with DS+ASD outperformed their peers with DS-ASD, mirroring the phenotypic advantage associated with iASD. We found no evidence of a relationship between attentional disengagement and visual search performance, providing preliminary evidence of a differentiation in terms of underlying visuo-attentional mechanism. CONCLUSION: We illustrate the value of progressing beyond insensitive behavioural measures of phenotypic description to examine, in a more fine-grained way, the attentional features associated with ASD comorbidity in children with DS

Electrodeposition of bismuth at a graphene modified carbon electrode and its application as an easily regenerated sensor for the electrochemical determination of the antimicrobial drug metronidazole

Metronidazole is a well-known antimicrobial drug that belongs to the nitroimidazole family of antibiotics. It has been widely used in the treatment of infections, but its accumulation in aquatic environments is an emerging concern. In this study a glassy carbon electrode was modified with graphene (Gr) nanoplatelets and bismuth. Both the Gr and Bi were electrochemically deposited onto the glassy carbon and the modified electrode was employed in the electrochemical detection of metronidazole. At the modified electrode, the reduction of metronidazole was found to be an adsorption-controlled reaction. The optimised sensor, which was fabricated within 6 min, exhibited good selectivity in the presence of various inorganic and organic compounds, good recovery in tap water, and exhibited a linear calibration curve extending from 0.005 to 260 μM, with a limit of detection of 0.9 nM. The sensor was easily regenerated through the simple oxidation of the Bi deposit followed by a 100 s reduction period in the Bi(III) solution to give a newly generated surface. Good reproducibility was achieved using this simple regeneration approach

Simple dispersion of carbon nanofibers in a naturally occurring polyphenol in water and their electrochemical characteristics

Carbon nanofibers are hydrophobic with poor dispersion in water. They are normally functionalised using highly acidic solutions and elevated temperatures. In this communication, we show that tannic acid can be employed at room temperature using a simple sonication method to give very good dispersions of the CNFs in distilled water. Using a factorial design, the three components, the sonication period, the concentration of tannic acid and the concentration of CNFs were found to be significant, while the concentration of the tannic acid as a single component had an equally significant effect. The optimum conditions were 1.0–1.25 mg mL−1 of CNFs, and 0.85 – 1.0 mM of tannic acid with a sonication period between 50 and 60 min. The well-dispersed CNFs exhibited very good electrochemical characteristics, with efficient electron transfer in the oxidation of acetaminophen, which was used as a model analyte