A technique is described to measure a surface self-diffusion coefficient (D) of a metal (gold) by scanning tunneling microscopy. Micro-hills formed on a gold face show a shape evolution by a diffusion transport of kink site atoms. D is determined via a measurement of the hill apex radius as a function of time and includes corrections of image errors. The technique shows that STM can be used to ...

In this article, we study eigenvalue problems with the p-Laplacian operator: −(|y′|p−2y′)′ = (p− 1)(λρ(x)− q(x))|y|p−2y on (0, πp), where p > 1 and πp ≡ 2π/(p sin(π/p)). We show that if ρ ≡ 1 and q is singlewell with transition point a = πp/2, then the second Neumann eigenvalue is greater than or equal to the first Dirichlet eigenvalue; the equality holds if and only if q is constant. The same ...

The dissociation of the horse hemoglobin molecule into 2 half molecules in 4 M urea solutions has been well established (16). The effect of concentrated urea on the equilibrium between oxygen and hemoglobin has, however, not been determined. The present experiments const.itute a study of this equilibrium. The reaction between oxygen and hemoglobin is best described if it is assumed that 4 molec...

This brief perspective article focuses on the most common errors and pitfalls, as well as the do's and don'ts in drug combination studies, in terms of experimental design, data acquisition, data interpretation, and computerized simulation. The Chou-Talalay method for drug combination is based on the median-effect equation, derived from the mass-action law principle, which is the unified theory ...

1 Center for Nanotechnology in Drug Delivery, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States, 2 Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States, 3 UNC Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, United S...

During the last few years, a number of works in computer simulation have focused on the clustering and percolation properties of simple fluids based in an energetic connectivity criterion proposed long ago by T.L. Hill [J. Chem. Phys. 23, 617 (1955)]. This connectivity criterion appears to be the most appropriate in the study of gas-liquid phase transition. So far, integral equation theories ha...

Genome-scale microarray datasets are noisy. We have previously reported an algorithm that yields highly specific genome-scale discovery of states of genetic expression. In its original implementation, the algorithm computes parameters by globally fitting data to a function containing a linear combination of elements that are similar to the Hill equation and the Michaelis-Menten differential equ...

Nonlinear analysis of anisotropic structures is described by using Hill’s yield criterion that anisotropic yield contour is assumed to be retained its shape during the hardening process. Nonlinear constitutive equation of anisotropic material is derived using plastic potential concept. Linear strain hardening model is utilized and forward Euler method is employed as a stress integration method....

In this paper, we will give, for the periodic solution of the scalar Newtonian 5 equation, some twist criteria which can deal with the fourth order resonant 6 case. These are established by developing some new estimates for the periodic 7 solution of the Ermakov–Pinney equation, for which the associated Hill equa8 tion may across the fourth order resonances. As a concrete example, the least 9 a...

The Ca2+ and voltage dependence of Ca(2+)-activated Cl- currents in rat parotid acinar cells was examined with the whole-cell patch clamp technique. Acinar cells were dialyzed with buffered free Ca2+ concentrations ([Ca2+]i) from < 1 nM to 5 microM. Increasing [Ca2+]i induced an increase in Cl- current at all membrane potentials. In cells dialyzed with [Ca2+]i > 25 nM, depolarizing test pulses ...