Browsing by Author "Hu, X"

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    Correlates of Parent-Child Physiological Synchrony and Emotional Parenting: Differential Associations in Varying Interactive Contexts
    (Journal of Child and Family Studies, 2019-04-01) Han, ZR; Gao, MM; Yan, J; Hu, X; Zhou, W; Li, X
    © 2019, The Author(s). Objectives: Parent-child synchrony during interaction might possess important features that underlie parenting processes throughout development. However, little is known regarding the association between parent-child physiological synchrony and emotional parenting behaviors during middle childhood. The main goal of the study was to examine whether emotional parenting was positively or negatively associated with parent-child physiological synchrony for school-age children. Methods: Adopting a biopsychosocial perspective, we incorporated the interbeat interval (IBI) and behavioral observation data of 150 parent-child dyads (child M age = 8.77, SD= 1.80) to explore the patterns of moment-to-moment dyadic physiological synchrony and to investigate whether these patterns were associated with two emotional parenting behaviors (psychological control and psychological unavailability). Results: Our findings provided some initial evidence that in low to moderately stressful situations that mimic daily parent-child interaction, parent-child physiological synchrony was indicative of different emotional parenting behaviors in various parent-child interactive situations. Specifically, in the collaborative context (parent-child working together to complete a task), parent-child physiological synchrony was indicative of less psychological unavailability, whereas in the competitive context (parent-child resolving disagreement with each other), parent-child physiological synchrony was indicative of less psychological control. The study implications and future research directions are discussed. Conclusions: Overall, our findings suggested that dyadic physiological synchrony, indexed by parent-child moment-to-moment matching of IBI, was associated with fewer negative emotional parenting behaviors.
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    Magnetophoretic circuits for digital control of single particles and cells.
    (Nat Commun, 2014-05-14) Lim, B; Reddy, V; Hu, X; Kim, K; Jadhav, M; Abedini-Nassab, R; Noh, Y; Lim, YT; Yellen, BB; Kim, C
    The ability to manipulate small fluid droplets, colloidal particles and single cells with the precision and parallelization of modern-day computer hardware has profound applications for biochemical detection, gene sequencing, chemical synthesis and highly parallel analysis of single cells. Drawing inspiration from general circuit theory and magnetic bubble technology, here we demonstrate a class of integrated circuits for executing sequential and parallel, timed operations on an ensemble of single particles and cells. The integrated circuits are constructed from lithographically defined, overlaid patterns of magnetic film and current lines. The magnetic patterns passively control particles similar to electrical conductors, diodes and capacitors. The current lines actively switch particles between different tracks similar to gated electrical transistors. When combined into arrays and driven by a rotating magnetic field clock, these integrated circuits have general multiplexing properties and enable the precise control of magnetizable objects.
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    Predicting the frequency dispersion of electronic hyperpolarizabilities on the basis of absorption data and thomas-kuhn sum rules
    (Journal of Physical Chemistry C, 2010-02-11) Hu, X; Xiao, D; Keinan, S; Asselberghs, I; Therien, MJ; Clays, K; Yang, W; Beratan, DN
    Successfully predicting the frequency dispersion of electronic hyperpolarizabilities is an unresolved challenge in materials science and electronic structure theory. We show that the generalized Thomas-Kuhn sum rules, combined with linear absorption data and measured hyperpolarizability at one or two frequencies, may be used to predict the entire frequency-dependent electronic hyperpolarizability spectrum. This treatment includes two- and three-level contributions that arise from the lowest two or three excited electronic state manifolds, enabling us to describe the unusual observed frequency dispersion of the dynamic hyperpolarizability in high oscillator strength M-PZn chromophores, where (porphinato)zinc(II) (PZn) and metal(II)polypyridyl (M) units are connected via an ethyne unit that aligns the high oscillator strength transition dipoles of these components in a head-to-tail arrangement. We show that some of these structures can possess very similar linear absorption spectra yet manifest dramatically different frequency dependent hyperpolarizabilities, because of three-level contributions that result from excited state-to excited state transition dipoles among charge polarized states. Importantly, this approach provides a quantitative scheme to use linear optical absorption spectra and very limited individual hyperpolarizability measurements to predict the entire frequency-dependent nonlinear optical response. Copyright © 2010 American Chemical Society.