Measurements of methane and nitrous oxide in human breath and the development of UK scale emissions.

Exhaled human breath can contain small, elevated concentrations of methane (CH4) and nitrous oxide (N2O), both of which contribute to global warming. These emissions from humans are not well understood and are rarely quantified in global greenhouse gas inventories. This study investigated emissions of CH4 and N2O in human breath from 104 volunteers in the UK population, to better understand what drives these emissions and to quantify national-scale estimates.

Superb resolution and contrast of transmission electron microscopy images of unstained biological samples on graphene-coated grids.

Background: In standard transmission electron microscopy (TEM), biological samples are supported on carbon films of nanometer thickness. Due to the similar electron scattering of protein samples and graphite supports, high quality images with structural details are obtained primarily by staining with heavy metals.

Methods: Single-layered graphene is used to support the protein self-assemblies of different molecular weights for qualitative and quantitative characterizations.

Dark-field transmission electron microscopy and the Debye-Waller factor of graphene.

Graphene's structure bears on both the material's electronic properties and fundamental questions about long range order in two-dimensional crystals. We present an analytic calculation of selected area electron diffraction from multi-layer graphene and compare it with data from samples prepared by chemical vapor deposition and mechanical exfoliation. A single layer scatters only 0.