Langzeitversuche zur Reproduzierbarkeit von Jodbestimmungen in Bewuchsproben nach der Sandell-Kolthoff-Reaktion

Ohne ZusammenfassungWir danken Herrn Prof. Dr. H. W. Nürnberg, Direktor des Instituts für Angewandte Physikalische Chemie für sein stetes Interesse am Fortgang der Arbeiten, Herrn R. Flucht für zuverlässige Mitarbeit.     

A multidimensional nonlinear sixth-order quantum diffusion equation

This paper is concerned with the analysis of a sixth-order nonlinear parabolic equation whose solutions describe the evolution of the particle density in a quantum fluid. We prove the global-in-time existence of weak nonnegative solutions in two and three space dimensions under periodic boundary conditions. Moreover, we show that these solutions are smooth and classical whenever the particle density is strictly positive, and we prove the long-time convergence to the spatial homogeneous equilibrium at a universal exponential rate. Our analysis strongly uses the Lyapunov property of the entropy functional.     

Cahn–Hilliard and thin film equations with nonlinear mobility as gradient flows in weighted-Wasserstein metrics

In this paper, we establish a novel approach to proving existence of non-negative weak solutions for degenerate parabolic equations of fourth order, like the Cahn–Hilliard and certain thin film equations. The considered evolution equations are in the form of a gradient flow for a perturbed Dirichlet energy with respect to a Wasserstein-like transport metric, and weak solutions are obtained as curves of maximal slope. Our main assumption is that the mobility of the particles is a concave function of their spatial density. A qualitative difference of our approach to previous ones is that essential properties of the solution – non-negativity, conservation of the total mass and dissipation of the energy – are automatically guaranteed by the construction from minimizing movements in the energy landscape.     

Existence of Weak Solutions to a Class of Fourth Order Partial Differential Equations with Wasserstein Gradient Structure

We prove the global-in-time existence of nonnegative weak solutions to a class of fourth order partial differential equations on a convex bounded domain in arbitrary spatial dimensions. Our proof relies on the formal gradient flow structure of the equation with respect to the L²-Wasserstein distance on the space of probability measures. We construct a weak solution by approximation via the time-discrete minimizing movement scheme; necessary compactness estimates are derived by entropy-dissipation methods. Our theory essentially comprises the thin film and Derrida-Lebowitz-Speer-Spohn equations.     

Zur Bestimmung der schwefligen S?ure im Hackfleisch

Ohne Zusammenfassung     

1,3,4-Oxadiazole-containing hybrids as potential anticancer agents: Recent developments,mechanism of action and structure-activity relationships

Chemotherapy is an important therapeutic approach for the treatment of cancer. Currently, many anticancer drugs are available in the market that plays an important role in cancer treatment, but concerns such as, drug resistance and side effects create an urgent need for the development of new anti-tumor drugs with high potency and less side effects. Heterocycles are of great interest due to their fascinating anticancer activity. Among them, 1,3,4-oxadiazoles showed attracting anti-tumor activity and its derivatives are under clinical trials for the treatment of cancer. Hybridization of 1,3,4-oxadiazole moiety with other heterocyclic pharmacophoresis a promising approach to overcome various disadvantages of current anticancer drugs such as drug resistance, toxicity, and other side effects. Thus, 1,3,4-oxadiazole-heterocycle hybrids occupy a significant position in the discovery of anti-tumor drugs. Among the reported oxadiazole-based hybrids reviewed here, compounds 45i, 59j, and 62x showed the highest anticancer activity with IC₅₀ values in the nanomolar range. This review summarizes the recent developments in the anticancer potential, structure–activity relationships, and mechanisms of actions of 1,3,4-oxadiazole-heterocycle hybrids.