Can pediatric sleep questions be incorporated into a risk model to predict respiratory complications following adenotonsillectomy?

Background: Adenotonsillectomy, one of the most frequent surgical procedures in children, is usually performed for sleep-disordered breathing, a disease spectrum from primary snoring to obstructive sleep apnea. Children undergoing an adenotonsillectomy may be at risk for perioperative respiratory complications, necessitating intervention or escalation of care. However, there is no effective preoperative screening or risk-stratification model for perioperative respiratory complications that incorporates not only clinical history and physical examination but also sleep question responses for children as there is for adults.

Determining the Gaussian Modulus and Edge Properties of 2D Materials: From Graphene to Lipid Bilayers.

The dominant deformation behavior of two-dimensional materials (bending) is primarily governed by just two parameters: bending rigidity and the Gaussian modulus. These properties also set the energy scale for various important physical and biological processes such as pore formation, cell fission and generally, any event accompanied by a topological change. Unlike the bending rigidity, the Gaussian modulus is, however, notoriously difficult to evaluate via either experiments or atomistic simulations.

Rigid proteins and softening of biological membranes-with application to HIV-induced cell membrane softening.

A key step in the HIV-infection process is the fusion of the virion membrane with the target cell membrane and the concomitant transfer of the viral RNA. Experimental evidence suggests that the fusion is preceded by considerable elastic softening of the cell membranes due to the insertion of fusion peptide in the membrane. What are the mechanisms underpinning the elastic softening of the membrane upon peptide insertion? A broader question may be posed: insertion of rigid proteins in soft membranes ought to stiffen the membranes not soften them.

Anomalous piezoelectricity in two-dimensional graphene nitride nanosheets.

Piezoelectricity is a unique property of materials that permits the conversion of mechanical stimuli into electrical and vice versa. On the basis of crystal symmetry considerations, pristine carbon nitride (C3N4) in its various forms is non-piezoelectric. Here we find clear evidence via piezoresponse force microscopy and quantum mechanical calculations that both atomically thin and layered graphitic carbon nitride, or graphene nitride, nanosheets exhibit anomalous piezoelectricity.

Ferroelectric switching of elastin.

Ferroelectricity has long been speculated to have important biological functions, although its very existence in biology has never been firmly established. Here, we present compelling evidence that elastin, the key ECM protein found in connective tissues, is ferroelectric, and we elucidate the molecular mechanism of its switching. Nanoscale piezoresponse force microscopy and macroscopic pyroelectric measurements both show that elastin retains ferroelectricity at 473 K, with polarization on the order of 1 μC/cm(2), whereas coarse-grained molecular dynamics simulations predict similar polarization with a Curie temperature of 580 K, which is higher than most synthetic molecular ferroelectrics.