As serious natural disasters, sandstorms have caused massive damages to the natural environment, national economy, and human health in the Middle East, Northern Africa, and Northern China. To avoid such damages, wireless sensor networks (WSNs) can be deployed in the regions where sandstorms generally originate so that sensor nodes can collaboratively monitor the origin and development of sandst...

Photosystem II uses water as an enzymatic substrate. It has been hypothesized that this water is vectored to the active site for water oxidation via water channels that lead from the surface of the protein complex to the Mn4O5Ca metal cluster. The radiolysis of water by synchrotron radiation produces amino acid residue-modifying OH(•) and is a powerful technique to identify regions of proteins ...

In response to membrane depolarization, voltage-gated ion channels undergo a structural rearrangement that moves charges or dipoles in the membrane electric field and opens the channel-conducting pathway. By combination of site-specific fluorescent labeling of the Shaker potassium channel protein with voltage clamping, this gating conformational change was measured in real time. During channel ...

We report on the fabrication of nanofluidic channels directly buried in silicate glass with transverse widths down to less than 50 nm using three-dimensional (3D) femtosecond laser direct writing. Using this technique, integrated micro-nanofluidic systems have been produced by simultaneously writing micro- and nanofluidic channels arranged into various 3D configurations in glass substrates. The...

Membrane proteins span a large variety of different functions such as cell-surface receptors, redox proteins, ion channels, and transporters. Proteins with functional pores show different characteristics of helix-helix packing as other helical membrane proteins. We found that the helix-helix contacts of 13 nonhomologous high-resolution structures of membrane channels and transporters are mainly...

We investigate the ability of polarization filtering to improve direct imaging of absorbing objects which are buried within scattering environments. We extend on previous empirical investigations by exploiting an efficient perturbation-based formalism, which is applicable to arbitrarily arranged sources and detectors with arbitrary polarizations. From this approach, we are able in some cases to...

We have probed internal and external accessibility of S4 residues to the membrane-impermeant thiol reagent methanethiosulfonate-ethyltrimethlammonium (MTSET) in both open and closed, cysteine-substituted Shaker K+ channels. Our results indicate that S4 traverses the membrane with no more than 5 amino acids in the closed state, and that the distribution of buried residues changes when channels o...

ground penetration radar (gpr) as a nondestructive method for identifying underground objects has been successfully applied to different fields of science such as geotechnical investigations, oil and gas exploration, geology, pipe detection and archeology investigations. metallic and nonmetallic objects can be identified by this method.  the depth of penetration is dictated by the gpr antennas....

The nicotinic acetylcholine receptor (nAChR) is a cation-selective channel central to both neuronal and muscular processes and is considered the prototype for ligand-gated ion channels, motivating a structural determination effort that spanned several decades [Unwin N (2005) Refined structure of the nicotinic acetylcholine receptor at 4 A resolution. J Mol Biol 346:967-989]. Purified nAChR must...

Here, we present a study of polar residues within the membrane core of alpha-helical membrane proteins. As expected, polar residues are less frequent in the membrane than expected. Further, most of these residues are buried within the interior of the protein and are only rarely exposed to lipids. However, the polar groups often border internal water filled cavities, even if the rest of the side...