für Naturforschung in cooperation with the Max Planck Society for the Advancement of Science under a Creative Commons Attribution 4.0 International License. Dieses Werk wurde im Jahr 2013 vom Verlag Zeitschrift für Naturforschung in Zusammenarbeit mit der Max-Planck-Gesellschaft zur Förderung der Wissenschaften e.V. digitalisiert und unter folgender Lizenz veröffentlicht: Creative Commons Namen...

Self-consistent GW calculations with efficient vertex corrections are employed to determine the electronic structure of liquid water. Nuclear quantum effects are taken into account through ab initio path-integral molecular dynamics simulations. We reveal a sizable band-gap renormalization of up to 0.7 eV due to hydrogen-bond quantum fluctuations. Our calculations lead to a band gap of 8.9 eV, i...

The structure and bonding in ionized water clusters, (H2O)(n)(+) (n = 3–9), has been studied using the basin hopping search algorithm in combination with quantum chemical calculations. Initially candidate low energy isomers were generated using basin hopping in conjunction with density functional theory. Subsequently, the structures and energies were refined using second order Møller–Plesset pe...

Dielectric and conductivity measurements are reported for bovine serum albumin as a function of hydration. Strong evidence is found for the existence of mobile charges whose short- and long-range hopping motion strongly depends on the physical state of the protein-bound water. These charges are considered to be protons. Insights into the nature of the electrical properties of protein-methylglyo...

The aquaporins (AQPs) are a family of small membrane-spanning proteins (monomer size approximately 30 kDa) that are expressed at plasma membranes in many cells types involved in fluid transport. This review is focused on the molecular structure and function of mammalian aquaporins. Basic features of aquaporin structure have been defined using mutagenesis, epitope tagging, and spectroscopic and ...

All aquaporins are efficient water transporters, while sustaining strict selectivity, even against protons, thereby maintaining the proton gradient across the cell membrane. Recently solved structures of these membrane channels have helped us to understand this remarkable property.

Intermolecular forces tend to organize water molecules into a tetrahedral lattice, conferring "crystalline" properties on the liquid. The simple ions, such as Na+, K+, and Cl-, have dinmensions which are of the same order as the water nmolecule. Therefore, in aqueous solution, ions can substitute for water molecules in the water lattice. However, because the force between ion and water molecule...

It is well known that positrons can live long enough to form complexes with atoms. The theoretical study of these complexes is important to interpret experimental data from both positron scattering by atoms and molecules and positron annihilation spectroscopy. There are typically two different kinds of positron complexes. In one of them a positron attaches to a neutral or ionic atom or molecule...

Land plants need water to replace the evaporation that occurs while atmospheric CO2 is diffusing into photosynthetic tissue. The water-for-carbon exchange rate is poor, and evolutionary history indicates a progression of innovations for cheap water transport—beginning in order with capillary suction at cell walls, stomatal regulation, hydroids, tracheids, secondary xylem, endodermis, and vessel...