Dynamics of a noncommutative monopole

We consider an electrically charged particle simultaneously interacting with a magnetic monopole and a dual monopole in the momentum space. It is a prototype of a three-dimensional system involving noncommuting and/or noncanonical variables but having geometric and also gauge symmetries in both the position and momentum spaces. We discuss the main features of the motions and conservation laws and the analogies to the case of planar motion.     

Antioxidant activity,lipophilicity and extractability of polyphenols from pig skin – development of analytical methods for skin permeation studies

Permeation of polyphenols through the stratum corneum barrier is a precondition for the protective action of polyphenols against oxidative skin damage. Prior to in vitro skin permeation experiments, we developed a method for the quantification of polyphenols in pig skin, including organic solvent extraction and HPLC analysis. Catechine hydrate, epigallocatechin gallate, trans‐resveratrol, quercetin, rutin and protocatechuic acid were chosen for this study as representatives of phenolics with different lipophilicity and molecular weight. The antioxidative activities of polyphenols as well as their octanol–water partition coefficients at different pH values were determined. Extraction of polyphenols from pig skin was optimized by variation of solvent composition, homogenization intensity and time, as well as partial exclusion of oxygen during extraction. The highest recovery rates could be reached by extraction with the methanol–water mixture (90:10, v/v), containing 0.2 g/L l ‐ascorbic acid, after the cryo‐milling for 4 min. Recoveries of 72% for total phenolics, 96% for quercetin and protocatechuic acid, 90% for rutin and 74% for trans‐resveratrol, were achieved. These extraction parameters will be selected for the polyphenol extraction from pig skin for further in vitro drug permeation studies. Copyright © 2013 John Wiley & Sons, Ltd.     

A comparison of the Discontinuous-Galerkin- and Spectral-Difference-Method on triangulations using PKD polynomials

This paper gives a first numerical comparison of the Discontinuous-Galerkin-(DG) and Spectral-Difference-Method (SD) under almost equivalent conditions for smooth test cases.     

On Weak Solutions of Stochastic Differential Equations II

In the first part of this article a new method of proving existence of weak solutions to stochastic differential equations with continuous coefficients having at most linear growth was developed. In this second part, we show that the same method may be used even if the linear growth hypothesis is replaced with a suitable Lyapunov condition.     

Increasing Complexity: A Practical Synthetic Approach to Three-Dimensional,Cyclic Sulfoximines and First Insights into Their in Vitro Properties

A short synthetic approach with broad scope to access five- to seven-membered cyclic sulfoximines in only two to three steps from readily available thiophenols is reported. Thus, simple building blocks were converted to complex molecular structures by a sequence of S-alkylation and one-pot sulfoximine formation, followed by intramolecular cyclization. Seventeen structurally diverse cyclic sulfoximines were prepared in high overall yields. In vitro evaluation of these underrepresented, three-dimensional, cyclic sulfoximines with respect to properties relevant to medicinal chemistry did not reveal any intrinsic flaw for application in drug discovery.