18 research outputs found

    Atypical Development of Attentional Control Associates with Later Adaptive Functioning, Autism and ADHD Traits

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    Funder: H2020 European Research Council; doi: http://dx.doi.org/10.13039/100010663Funder: Research Foundation FlandersFunder: Universiteit Gent; doi: http://dx.doi.org/10.13039/501100004385Funder: Marguerite-Marie DelacroixFunder: Autistica; doi: http://dx.doi.org/10.13039/100011706Funder: Riksbankens Jubileumsfond; doi: http://dx.doi.org/10.13039/501100004472; Grant(s): NHS14-1802:1Funder: K.F. Hein FondsFunder: Scott Family Junior Research FellowshipAbstract: Autism is frequently associated with difficulties with top-down attentional control, which impact on individuals’ mental health and quality of life. The developmental processes involved in these attentional difficulties are not well understood. Using a data-driven approach, 2 samples (N = 294 and 412) of infants at elevated and typical likelihood of autism were grouped according to profiles of parent report of attention at 10, 15 and 25 months. In contrast to the normative profile of increases in attentional control scores between infancy and toddlerhood, a minority (7–9%) showed plateauing attentional control scores between 10 and 25 months. Consistent with pre-registered hypotheses, plateaued growth of attentional control was associated with elevated autism and ADHD traits, and lower adaptive functioning at age 3 years

    Block copolymers as bile salt sequestrants: intriguing structures formed in a mixture of an oppositely charged amphiphilic block copolymer and bile salt

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    To study the formation and characterize the structure of mixed complexes of oppositely charged block copolymers and surfactants are of great significance for practical applications, e.g., in drug carrier formulations that are based on electrostatically assisted assembly. In this context, biocompatible block copolymers and biosurfactants (like bile salts) are particularly interesting. In this work, we report on the co-assembly in dilute aqueous solution between a cationic poly(N-isopropyl acryl amide) (PNIPAM) diblock copolymer and the oppositely charged bile salt surfactant sodium deoxycholate at ambient temperature. The cryogenic transmission electron microscopy (cryo-TEM) experiments revealed the co-existence of two types of co-assembled complexes of radically different morphology and inner structure. They are formed mainly as a result of the electrostatic attraction between the positively charged copolymer blocks and bile salt anions and highlight the potential of using linear amphiphilic block copolymers as bile salt sequestrants in the treatment of bile acid malabsorption and hypercholesterolemia. The first complex of globular morphology has a coacervate core of deoxycholate anions and charged copolymer blocks surrounded by a PNIPAM corona. The second complex has an intriguing tape-like supramolecular morphology of several micrometer in length that is striped in the direction of the long axis. A model is presented in which the stretched cationic blocks of several block copolymers interact electrostatically with the bile salt molecules that are associated to form a zipper-like structure. The tape is covered on both sides by the PNIPAM chains that stabilize the overall complex in solution. In addition to cryo-TEM, the mixed system was investigated in a range of molar charge fractions at a constant copolymer concentration by static light scattering, small angle X-ray scattering, and electrophoretic mobility measurements. © 2019 the Owner Societies

    Effect of temperature on the association behavior in aqueous mixtures of an oppositely charged amphiphilic block copolymer and bile salt

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    The association in aqueous mixtures of a thermoresponsive cationic diblock copolymer composed of poly(N-isopropylacrylamide) (PNIPAM) and poly(3-acrylamidopropyl)-trimethylammonium-chloride (PAMPTMA(+)) and the oppositely charged bile salt sodium deoxycholate (NaDC) is investigated at different compositions by light and X-ray scattering, calorimetry, and electrophoretic mobility measurements. Clouding reveals aggregation upon heating. The addition of NaDC to the copolymer solution lowers the temperature of the transition and increases its cooperativity. At high temperature and low NaDC fractions, mixed aggregates with a dehydrated PNIPAM-rich interior and a PAMPTMA(+)-rich shell partially neutralized by DC– anions are formed. At high NaDC fractions, the aggregates present internal regularly spaced segregated nanoregions of dehydrated PNIPAM and PAMPTMA(+)/DC– (microphase separation). The results suggest that the mixed aggregates have appealing composition-controlled thermoresponse. The system phase separates at body temperature and the highest NaDC fractions investigated, meaning in conditions accomplished when the use of the polymer as a bile salt sequestrant is hypothesized

    Atypical Development of Attentional Control Associates with Later Adaptive Functioning, Autism and ADHD Traits

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    Autism is frequently associated with difficulties with top-down attentional control, which impact on individuals’ mental health and quality of life. The developmental processes involved in these attentional difficulties are not well understood. Using a data-driven approach, 2 samples (N = 294 and 412) of infants at elevated and typical likelihood of autism were grouped according to profiles of parent report of attention at 10, 15 and 25 months. In contrast to the normative profile of increases in attentional control scores between infancy and toddlerhood, a minority (7–9%) showed plateauing attentional control scores between 10 and 25 months. Consistent with pre-registered hypotheses, plateaued growth of attentional control was associated with elevated autism and ADHD traits, and lower adaptive functioning at age 3 years
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