Reversible Fluorination of Graphene: towards a Two-Dimensional Wide Bandgap Semiconductor

We report the synthesis and evidence of graphene fluoride, a two-dimensional wide bandgap semiconductor derived from graphene. Graphene fluoride exhibits hexagonal crystalline order and strongly insulating behavior with resistance exceeding 10 G$\Omega$ at room temperature. Electron transport in graphene fluoride is well described by variable-range hopping in two dimensions due to the presence of localized states in the band gap. Graphene obtained through the reduction of graphene fluoride is highly conductive, exhibiting a resistivity of less than 100 k$\Omega$ at room temperature. Our approach provides a new path to reversibly engineer the band structure and conductivity of graphene for electronic and optical applications.Comment: 7 pages, 5 figures, revtex, to appear in PR

Avian infectious bronchitis vírus (IBV): effect of vaccine doses on mucosal imune responses and protection after challenge in chickens.

Projeto/Plano de Ação: 05.11.11.002

Immune-protection mechanisms against late challenge with avian infectious bronchitis vírus (IBV) induced by a single-dose of an attenuated vaccine in day-old chicks.

Projeto/Plano de Ação: 05.11.11.00

Cloned nucleoprotein (NP) gene of avian influenza virus for using as a positive control in syber green I real time RT-PCR (RRT-PCR).

Projeto/Plano de Ação: 11.11.11.111

Observation of Magnon Polarization

We measure the mode-resolved direction of the precessional motion of the magnetic order, i.e., magnon polarization, via the chiral term of inelastic polarized neutron scattering spectra. The magnon polarization is a unique and unambiguous signature of magnets and is important in spintronics, affecting thermodynamic properties such as the magnitude and sign of the spin Seebeck effect. However, it has never been directly measured in any material until this work. The observation of both signs of magnon polarization in Y3Fe5O12 also gives direct proof of its ferrimagnetic nature. The experiments agree very well with atomistic simulations of the scattering cross section

Sedimentation rates test models of oceanic detachment faulting

This is the accepted manuscript version.The final version is available from Wiley at http://onlinelibrary.wiley.com/doi/10.1002/2014GL061555/full.Long-lived detachment faults play an important role in the construction of new oceanic crust at slow-spreading mid-oceanic ridges. Although the corrugated surfaces of exposed low-angle faults demonstrate past slip, it is difficult to determine whether a given fault is currently active. If inactive, it is unclear when slip ceased. This judgment is crucial for tectonic reconstructions where detachment faults are present, and for models of plate spreading. We quantify variation in sediment thickness over two corrugated surfaces near 16.5°N at the Mid-Atlantic Ridge using near-bottom CHIRP data. We show that the distribution of sediment and tectonic features at one detachment fault is consistent with slip occurring today. In contrast, another corrugated surface 20 km to the south shows a sediment distribution suggesting that slip ceased ~150,000 years ago. Data presented here provide new evidence for active detachment faulting, and suggest along-axis variations in fault activity occur over tens of kilometers.This work was supported by the National Science Foundation grant number OCE-1155650

Multiple early gastric cancer with duodenal invasion

This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens