Pharmacophore features for machine learning in pharmaceutical virtual screening

Molecular Diversity - Methods of three-dimensional molecular alignment generally treat all pharmacophore features equally when superimposing. However, some pharmacophore features can be more...     

Interaction between a stationary mercury electrode and a hydrogen bubble in an aqueous sodium dodecyl sulphate solution

The stability and rupture of thin liquid films formed from an aqueous solution of Na₂SO₄ (0.05 mol dm⁻³) in the presence of 5 × 10⁻⁵ mol dm⁻³ sodium dodecyl sulphate between a stationary mercury electrode and a hydrogen bubble has been investigated as a function of electrode potential. The electrostatic component of disjoining pressure has been calculated using the results of capacity measurement for the mercury-solution interface. Special attention has been paid to films formed on positively charged mercury surfaces. In this case, despite the positive electrode polarization, the outer Helmholtz plane potential is found to be negative due to the high surface activity of the dodecyl sulphate anion. The van der Waals component of disjoining pressure has been calculated on the basis of a double sheath model of the two interacting surfaces, taking into consideration the orientation of the adsorbed surfactant layers at the interfaces. Calculations of the total disjoining pressure can explain film stability at negative mercury potentials, but do not explain film rupture when the polarization of the mercury is positive. The existence of a hydrophobic attractive interaction is postulated in the latter case.     

Canonical kernels for density estimation

The kernel function in density estimation is uniquely determined up to a scale factor. In this paper, we advocate one particular rescaling of a kernel function, called the canonical kernel, because it is the only version which uncouples the problems of choice of kernel and choice of scale factor. This approach is useful for both pictorial comparison of kernel density estimators and for optimal kernel theory.     

Initial stages of oxidation of GaAs(111)2 × 2-Ga surfaces

The initial interaction of oxygen at room temperature with GaAs(111)2 × 2-Ga surfaces has been studied by quantitative Auger analysis and low-energy electron diffraction, under different electron irradiation and gas ionization conditions. Oxygen fills first the non-vacancy overlayer sites with a preferential bond to the Ga atoms. This adsorption phase is characterized by the absence of chemical shifts in the Ga Auger peaks that involve core levels. The oxidation stage begins with the occupation of the underlayer sites below the first Ga-As bilayer. For coverages lower than 2 monolayers oxygen adsorption and incorporation takes place without any loss of Ga or As atoms of the surface layers. Electron irradiation and gas ionization of the oxygen-covered surface increase the kinetics up to two orders of magnitude, but no changes in the adsorption sites and/or occupation sequence have been detected.     

Fuzzy confidence intervals in a theory of economic rationality

This paper discusses the treatment of uncertainty as it appears in economic affairs. A focal theory of rational behavior under uncertainty is proposed and an empirical implication is pointed out in industrial economics. The central formal concept is the fuzzy confidence interval.     

Influence of sintering conditions on chemical composition of NASICON

The influence of various sintering conditions on the chemical composition and on some physical properties of undoped and CaO or MgO doped NASICON ceramics was studied. The synthesized material was characterized by a few experimental techniques, including the wet chemical analysis and the admittance spectroscopy. The dopants were found to be located in the glassy phase formed during sintering of NASICON material. The electrical properties of NASICON were strongly affected by sintering conditions.     

Comments on the symmetry relations in the hyperon radiative decays

We demonstrate that in general Hara's theorem which gives various symmetry relations for the hyperon radiative decays is not valid. The new relations we derive are different from those given by Hara. But for the Σ⁺→P_γ decay, the asymmetry parameter is still zero in the exact SU(3) limit.     

BRS analysis of Zamolodchikov's spin 2 and 3 current algebra

We construct the BRS operator of Zamolodchikov's spin 2 and 3 associative current algebra. This algebra is not a Lie algebra, since the commutator of two spin 3 fields involves the square of the spin 2 field. Nevertheless, the associated BRS operator is nilpotent when the central charge of the Virasoro subalgebra is 100 and the energy of the vacuum −4.     

Solution of the TDHF equation for atomic collisions by expanding the one-particle density matrix into gaussian matrices

The TDHF equation for the one-particle density matrix is solved by expanding the density matrix into gaussian matrices. The method is specialized to spherically symmetric problems of many-electron atoms and applied to the calculation of probabilities for excitation and ionisation of Li⁺ created by β⁻ - decay of ⁶He.