Relationship between GC content and intron size.

<p>GC contents in three size intervals from the three populations (DAF <0.1): YRI (A), CEU (B), and JPTCHB (C) as well as the combined data (all introns; D). The horizontal lines in the boxplots indicate the upper, the median, and the lower quartiles (from the top to the bottom).</p

RDI (DAF<0.1) when examining dependence of GC-effect on intron length.

<p>RDI (DAF<0.1) when examining dependence of GC-effect on intron length.</p

RDI (DAF<0.1) in different intron size intervals from combined datasets of the three populations.

<p>RDI (DAF<0.1) in different intron size intervals from combined datasets of the three populations.</p

RDI (DAF<0.1) under variable size intervals and GC-contents.

<p>RDI (DAF<0.1) under variable size intervals and GC-contents.</p

Median GC contents in variable intron size intervals and regions.

<p>*We pooled both 5′-exon and 3′-exon data as flanking exon data and compared them with intron data. The <i>P</i> values were calculated based on Wilcoxon rank sum test.</p

Estimation of key parameters.

<p>The distributions of derived allele frequency or DAF (A) and GC content (B) of minimal introns among the three studied populations: Africans (YRI), Europeans (CEU), and Asians (JPTCHB). The dashed lines divide the thresholds for DAF (A) and intron GC content (B).</p

High and Selective Carbon Dioxide Capture in Nitrogen-Containing Aerogels via Synergistic Effects of Electrostatic In-Plane and Dispersive π–π-Stacking Interactions

A new strategy for CO₂ capture is reported based on the synergistic effect of electrostatic in-plane and dispersive π–π-stacking interactions of amide and indole with CO₂. Density functional theory illustrated that the amide group can have an increased ability to capture CO₂ molecules that were just desorbed from an adjacent indole unit. We used this strategy to fabricate a microporous aerogel that exhibited a superior CO₂ capture performance in both dry and wet conditions. The proposed synergistic effect is expected to be a new rationale for the design of CO₂ capture materials

Dynamic Molecular Behavior on Thermoresponsive Polymer Brushes

The surface dynamics of individual surfactant and polymer molecules on thermally responsive polymer brushes (poly­(<i>N</i>-isopropylacrylamide), PNIPAAM) were studied using high throughput single molecule tracking microscopy. The probe molecules universally exhibited intermittent hopping motion, in which the diffusion switched between mobility and confinement with a broad distribution of waiting times; this was analyzed in the context of a continuous time random walk (CTRW) model described using “waiting time” and “flight length” distributions. We found that the surface mobility, which was affected by waiting times and flight lengths, of both probe molecules increased abruptly with temperature above the 32 °C lower critical solution temperature (LCST) transition of the PNIPAAM brush. In particular, above the LCST, where the polymer brush collapsed into a more hydrophobic dense polymer film, the effective diffusion coefficients and mobile fraction of probe molecule increased, suggesting that mobility was inhibited by penetration into the brush at lower temperatures. Waiting times at lower temperature were twice as long as at higher temperatures, and the longest flight length increased from 0.9 to 1.8 μm. Moreover, we found that the high density of strong binding sites available on the swollen PNIPAAM brush led to long waiting times and a high probability of readsorption, which resulted in short flight lengths, while the absence of strong binding sites on collapsed PNIPAAM films led to short waiting times and long flights

Nanoscale Topography Influences Polymer Surface Diffusion

Using high-throughput single-molecule tracking, we studied the diffusion of poly(ethylene glycol) chains at the interface between water and a hydrophobic surface patterned with an array of hexagonally arranged nanopillars. Polymer molecules displayed anomalous diffusion; in particular, they exhibited intermittent motion (<i>i.e.</i>, immobilization and “hopping”) suggestive of continuous-time random walk (CTRW) behavior associated with desorption-mediated surface diffusion. The statistics of the molecular trajectories changed systematically on surfaces with pillars of increasing height, exhibiting motion that was increasingly subdiffusive and with longer waiting times between diffusive steps. The trajectories were well-described by kinetic Monte Carlo simulations of CTRW motion in the presence of randomly distributed permeable obstacles, where the permeability (the main undetermined parameter) was conceptually related to the obstacle height. These findings provide new insights into the mechanisms of interfacial transport in the presence of obstacles and on nanotopographically patterned surfaces

Temporally Anticorrelated Motion of Nanoparticles at a Liquid Interface

Quantum dots at the hexane–glycerol interface exhibited unexpected behavior including highly dynamic adsorption/desorption, where the lateral nanoparticle motion was anomalously fast immediately after adsorption and prior to desorption. At the interface, particles exhibited pseudo-Brownian lateral motion, in which the instantaneous diffusion coefficient was temporally anticorrelated, in agreement with our simulations involving fractional Brownian motion in the surface-normal direction. These phenomena suggest that, in contrast to the conventional picture for colloidal particles, nanoparticles explore a landscape of metastable interfacial positions, with different exposures to the two adjacent phases