4 research outputs found
Poly(ethylene oxide)-sodium dodecyl sulfate interactions studied using static and dynamic light scattering
Static and dynamic light scattering measurements have been made on poly(ethy1ene oxide)
(PEO) in the presence of the ionic surfactant sodium dodecyl sulfate (SDS) in aqueous solution over a range
of relative concentrations. The purpose was, in part, to demonstrate the polyelectrolyte effecte which arise
in PEO on formation of the charged complex between the components in solution in which small SDS micelles
are incorporated into the flexible PEO coil. The influence of the ionic strength of the medium was studied.
Static light scattering measurements show that the radius of gyration changes as a function of SDS concentration
and the ionic strength of the medium. Diffusion coefficients from dynamic light scattering (DLS) reflect
changes in the pair interaction potential as the SDS and ionic strength are altered. Laplace inversion of the
DLS time correlation function gives relaxation time distributions consisting of the PEO/SDS complex as the
main component and free SDS micelles as the minor component. Changes in peak areas are related to the
increase in the degree of binding between SDS and PEO as the relative concentrations change and also the
increase in SDS micellar size with increase in the ionic strength of the medium
Interactions between a 30 Charged Polyelectrolyte and an Anionic Surfactant in Bulk and at a Solid−Liquid Interface
Study protocol of comprehensive risk evaluation for anorexia nervosa in twins (CREAT) : a study of discordant monozygotic twins with anorexia nervosa.
BACKGROUND: Anorexia nervosa (AN) is a severe disorder, for which genetic evidence suggests psychiatric as well as metabolic origins. AN has high somatic and psychiatric comorbidities, broad impact on quality of life, and elevated mortality. Risk factor studies of AN have focused on differences between acutely ill and recovered individuals. Such comparisons often yield ambiguous conclusions, as alterations could reflect different effects depending on the comparison. Whereas differences found in acutely ill patients could reflect state effects that are due to acute starvation or acute disease-specific factors, they could also reflect underlying traits. Observations in recovered individuals could reflect either an underlying trait or a "scar" due to lasting effects of sustained undernutrition and illness. The co-twin control design (i.e., monozygotic [MZ] twins who are discordant for AN and MZ concordant control twin pairs) affords at least partial disambiguation of these effects. METHODS: Comprehensive Risk Evaluation for Anorexia nervosa in Twins (CREAT) will be the largest and most comprehensive investigation of twins who are discordant for AN to date. CREAT utilizes a co-twin control design that includes endocrinological, neurocognitive, neuroimaging, genomic, and multi-omic approaches coupled with an experimental component that explores the impact of an overnight fast on most measured parameters. DISCUSSION: The multimodal longitudinal twin assessment of the CREAT study will help to disambiguate state, trait, and "scar" effects, and thereby enable a deeper understanding of the contribution of genetics, epigenetics, cognitive functions, brain structure and function, metabolism, endocrinology, microbiology, and immunology to the etiology and maintenance of AN