6,253 research outputs found
Hydration of a B-DNA Fragment in the Method of Atom-atom Correlation Functions with the Reference Interaction Site Model Approximation
We propose an efficient numerical algorithm for solving integral equations of
the theory of liquids in the Reference Interaction Site Model (RISM)
approximation for infinitely dilute solution of macromolecules with a large
number of atoms. The algorithm is based on applying the nonstationary iterative
methods for solving systems of linear algebraic equations. We calculate the
solvent-solute atom-atom correlation functions for a fragment of the B-DNA
duplex d(GGGGG).d(CCCCC) in infinitely dilute aqueous solution. The obtained
results are compared with available experimental data and results from computer
simulations.Comment: 9 pages, RevTeX, 9 pages of ps figures, accepted for publications in
JC
Condensation of Silica Nanoparticles on a Phospholipid Membrane
The structure of the transient layer at the interface between air and the
aqueous solution of silica nanoparticles with the size distribution of
particles that has been determined from small-angle scattering has been studied
by the X-ray reflectometry method. The reconstructed depth profile of the
polarizability of the substance indicates the presence of a structure
consisting of several layers of nanoparticles with the thickness that is more
than twice as large as the thickness of the previously described structure. The
adsorption of 1,2-distearoyl-sn-glycero-3-phosphocholine molecules at the
hydrosol/air interface is accompanied by the condensation of anion silica
nanoparticles at the interface. This phenomenon can be qualitatively explained
by the formation of the positive surface potential due to the penetration and
accumulation of Na+ cations in the phospholipid membrane.Comment: 7 pages, 5 figure
Structure And Properties of Nanoparticles Formed under Conditions of Wire Electrical Explosion
Structure and properties of nanoparticles formed under conditions of wire
electrical explosion were studied. It was shown that the state of WEE power
particles can be characterized as a metastable state. It leads to an increased
stability of nanopowders at normal temperatures and an increased reactivity
during heating, which is revealed in the form of threshold phenomena.Comment: Submitted on behalf of TIMA Editions
(http://irevues.inist.fr/tima-editions
Distances to 10 nearby galaxies observed with the Hubble space telescope
Images of 10 galaxies in F814W and F606W filters obtained on the Hubble Space
Telescope (HST) are used to construct color-magnitude diagrams for the star
population of these galaxies. The distances to the galaxies are estimated from
the luminosity of the tip of the red giant branch. The galaxies examined here
have radial velocities from 250 to 760 km/s relative to the centroid of the
Local Group and distances ranging from 3.7 to 13.0 Mpc. Several other observed
galaxies with low radial velocities are noted at distances beyond the limit of
13 Mpc.Comment: 7 pages, 1 table, 4 figures, published in Astrofizic
- …