Use of Immunomatrix Methods to Improve Protein-Protein Interaction Detection

Immunoprecipitation (IP) and coimmunoprecipitation (co-IP) are key techniques for studying protein-protein interactions. These methods utilize immobilized protein A or protein G to isolate antibody-bound target antigens. The main disadvantage of traditional immunoprecipitation and coimmunoprecipitation is that the conditions used to elute the precipitated antigen also release the antibody, contaminating the antigen and destroying the antibody support. To overcome these problems, we describe two methods to generate a reusable antibody support by cross-linking the antibody to immobilized protein A or protein G, or by coupling it directly to the resin. Our studies have demonstrated that the immobilization efficiency for the antibody coupling method was similar for several species of antibody. Furthermore, we illustrate that using both methods of antibody immobilization yields IP and co-IP results similar to traditional protocols but eliminates the antibody heavy and light chains contamination

Psychosocial determinants of physical activity in children attending afterschool programs : a path analysis.

Background: Physical activity (PA) is important for controlling childhood obesity, but a comprehensive PA model for school-aged children is lacking. Objectives: Guided by the youth PA promotion (YPAP) model, this study estimated the direct and indirect effects of self-efficacy, enjoyment, parental influence, and environment on self-reported PA and pedometer steps. A secondary purpose was to explore the association between self-reported PA and pedometer steps. Methods: An observational and prospective study was conducted among 133 children, aged 8–11 years old, from 10 elementary schools with afterschool programs in a Midwestern U.S. school district from August through October 2013. PA was assessed by a 7-day recall scale and pedometers. Other variables were assessed by validated questionnaires. Results: Approximately 65 (49%) children were overweight or obese—only 17 (13%) met national PA recommendations—and body mass index z score was negatively correlated with pedometer steps (r = .18, p = .042). A path analysis showed that self-efficacy had a direct effect on self-reported PA and pedometer steps, enjoyment had only a direct effect on self-reported PA, and parental influence had a direct effect on pedometer steps and an indirect effect on self-reported PA through self-efficacy and enjoyment. The association between self-reported PA and pedometer steps was not significant. Discussion: Because this study only partially supports the YPAP model, studies with a larger sample size and longitudinal design are essential to further examine this model. The nonsignificant relationship of self-reported PA with pedometer steps may be due to the systematic error resulted from a common method artifact of self-report. Given the importance of parental influence, enjoyment, and self-efficacy, targeting these three determinants in future interventions to increase PA among children is recommended

Selecting and tailoring implementation interventions: A concept mapping approach

© 2020 The Author(s). Background: To improve the uptake of research into practice, knowledge translation frameworks recommend tailoring implementation strategies to address practice barriers. This study reports our experience pairing the Theoretical Domains Framework with information from multiple stakeholder groups to co-develop practice-informed strategies for improving the implementation of an evidence-based outcome measurement tool across a large community health system for preschoolers with communication impairments. Methods: Concept mapping was used to identify strategies for improving implementation of the Focus on the Outcomes of Communication Under Six (FOCUS) in Ontario Canada\u27s Preschool Speech and Language Program. This work was done in five stages. First, we interviewed 37 speech-language pathologists (clinicians) who identified 90 unique strategies to resolve practice barriers to FOCUS implementation. Second, clinicians (n = 34), policy-makers (n = 3), and members of the FOCUS research team (n = 6) sorted and rated the strategies by importance and feasibility. Third, stakeholders\u27 sorting data were analyzed to generate a two-dimensional concept map. Based on the rating data from stakeholders, we prioritized a list of strategies that were rated as highly important and highly feasible, and summarized the practice barriers addressed by each of the prioritized strategies. Fourth, we validated these findings with stakeholders via an online survey. Fifth, the mechanisms of action of the prioritized list of strategies were considered based on available evidence from the Theoretical Domains Framework and associated behavior change literature. Results: Stakeholders categorized the 90 unique implementation strategies into a six-cluster concept map. Based on stakeholders\u27 ratings, a list of 14 implementation strategies were prioritized. These implementation strategies were reported to resolve barriers within the environmental context and resources and beliefs about consequences domains of the Theoretical Domains Framework. All but one of the prioritized strategies have a demonstrated link in resolving existing barriers according to the behavioral change literature. Conclusions: Our study contributes to a growing literature that demonstrates the process of tailoring implementation strategies to specific barriers. Practical drawbacks and benefits of using concept mapping as a way to engage stakeholders in implementation research are discussed

Direct Evidence of the Exfoliation Efficiency and Graphene Dispersibility of Green Solvents toward Sustainable Graphene Production

Achieving a sustainable production of pristine high-quality graphene and other layered materials at a low cost is one of the bottlenecks that needs to be overcome for reaching 2D material applications at a large scale. Liquid phase exfoliation in conjunction with N-methyl-2-pyrrolidone (NMP) is recognized as the most efficient method for both the exfoliation and dispersion of graphene. Unfortunately, NMP is neither sustainable nor suitable for up-scaling production due to its adverse impact on the environment. Here, we show the real potential of green solvents by revealing the independent contributions of their exfoliation efficiency and graphene dispersibility to the graphene yield. By experimentally separating these two factors, we demonstrate that the exfoliation efficiency of a given solvent is independent of its dispersibility. Our studies revealed that isopropanol can be used to exfoliate graphite as efficiently as NMP. Our finding is corroborated by the matching ratio between the polar and dispersive energies of graphite and that of the solvent surface tension. This direct evidence of exfoliation efficiency and dispersibility of solvents paves the way to developing a deeper understanding of the real potential of sustainable graphene manufacturing at a large scale

Mechanisms and kinetics of C-S-H nucleation approaching the spinodal line: Insights into the role of organics additives

Wet chemistry C-S-H precipitation experiments were performed under controlled conditions of solution supersaturation in the presence and absence of gluconate and three hexitol molecules. Characterization of the precipitates with SAXS and cryo-TEM experiments confirmed the presence of a multi-step nucleation pathway. Induction times for the formation of the amorphous C-S-H spheroids were determined from light transmittance. Analysis of those data with the classical nucleation theory revealed a significant increase of the kinetic prefactor in the same order as the complexation constants of calcium and silicate with each of the organics. Finally, two distinct precipitation regimes of the C-S-H amorphous precursor were identified: i) a nucleation regime at low saturation indexes (SI) and ii) a spinodal nucleation regime at high SI where the free energy barrier to the phase transition is found to be of the order of the kinetic energy or less.Comment: Accepted in Cement and Concrete Research. 30 pages plus supplementary materials. arXiv admin note: substantial text overlap with arXiv:2111.0274