Low-temperature single-crystal neutron and X-ray diffraction data were collected for bullvalene (Figure 1). X —N Fourier and multipole static deformation electron density maps were calculated and compared. Atomic mean-square-displacement parameters were analysed in the framework of the rigid-body motion model and the residual amplitudes (UOBS — t/TLS) were graphically interpreted. The prelimina...

We study the Euclidean two-point correlation function Gq(x) of the topological charge density in QCD. A general statement based on reflection positivity tells us that Gq(x) < 0 for x 6= 0. On the other hand the topological susceptibility χq = ∫ dxGq(x) is a positive quantity. This indicates that Gq(x) developes a positive contact term at x = 0, that contributes to the determination of the physi...

Crystallographic perturbations to valence charge densityand hydrogen-surface interactions

An analytical solution for the distribution of surface charge on a dielectric sphere due to the presence of an external point charge is presented. This solution describes how charge on the surface of the sphere is polarised in the electric field into regions of negative and positive charge. The polarisation effect (distribution of surface charge) generally varies with the separation between the...

T HE SURFACE CHARGE OF MAMMALIAN CELLS is considered to be one of several factors determining the balance between attractive and repulsive forces that operate between the cell periphery and other surfaces of potential contact.1’2 The surface-charge density of the leukocyte may be important in determining surface characteristics such as adhesiveness, deformability, and pseudopod formation. Varia...

T HE SURFACE CHARGE OF MAMMALIAN CELLS is considered to be one of several factors determining the balance between attractive and repulsive forces that operate between the cell periphery and other surfaces of potential contact.1’2 The surface-charge density of the leukocyte may be important in determining surface characteristics such as adhesiveness, deformability, and pseudopod formation. Varia...

T HE SURFACE CHARGE OF MAMMALIAN CELLS is considered to be one of several factors determining the balance between attractive and repulsive forces that operate between the cell periphery and other surfaces of potential contact.1’2 The surface-charge density of the leukocyte may be important in determining surface characteristics such as adhesiveness, deformability, and pseudopod formation. Varia...

T HE SURFACE CHARGE OF MAMMALIAN CELLS is considered to be one of several factors determining the balance between attractive and repulsive forces that operate between the cell periphery and other surfaces of potential contact.1’2 The surface-charge density of the leukocyte may be important in determining surface characteristics such as adhesiveness, deformability, and pseudopod formation. Varia...

We have developed a theoretical model [1] for ionic transport through synthetic conical nanopores. The results have been compared with experiments obtained for single, gold–coated conical nanopores. The model [1] describes quantitatively the ionic transport through synthetic conical nanopores. It is based on the Poisson and Nernst-Planck (PNP) equations and allows the calculation of realistic p...

A mixed bilayer of cholesterol and dimyristoylphosphatidylcholine has been formed on a gold-coated block of quartz by fusion of small unilamellar vesicles. The formation of this bilayer lipid membrane on a conductive surface allowed us to study the influence of the support's surface charge on the structure and hydration of the bilayer lipid membrane. We have employed electrochemical measurement...