Syntheses of C-5-spirocyclic C-glycoside SGLT2 inhibitors

Several syntheses of C-5-spirocycle-containing C-glycosides are discussed. A multigram-scale synthesis capitalizing on a one-pot aldol-Cannizzaro sequence is described. Spiro oxetane formation using an unprotected penta-ol C-glycoside as substrate is also exemplified. Functional assessment of these compounds for potency and selectivity was evaluated at human SGLT2 and SGLT1.     

Speciation Analyses by Differential Atomization Using a Platinum Loop-Carbon Bed Dual Stage Atomizer

It has become increasingly evident in recent years that the toxicity of a metal is dependent not only on its concentration but also on its particular chemical form. The chemical form of an element determines metabolic effects and therefore its toxicity. Speciation of heavy metals may also influence the synergistic effects of groups of elements in the biospheres¹.     

Optimal adaptive replacement in a renewal process

In this paper we present an exact method for computing the Weibull renewal function and its derivative for application in maintenance optimization. The computational method provides a solid extension to previous work by which an approximation to the renewal function was used in a Bayesian approach to determine optimal replacement times. In the maintenance scenario, under the assumption an item is replaced by a new one upon failure, the underlying process between planned replacement times is a renewal process. The Bayesian approach takes into account failure and survival information at each planned replacement stage to update the optimal time until the next planned replacement. To provide a simple approach to carry out in practice, we limit the decision process to a one‐step optimization problem in the sequential decision problem. We make the Weibull assumption for the lifetime distribution of an item and calculate accurately the renewal function and its derivative. A method for finding zeros of a function is adapted to the maintenance optimization problem, making use of the availability of the derivative of the renewal function. Furthermore, we develop the maximum likelihood estimate version of the Bayesian approach and illustrate it with simulated examples. The maintenance algorithm retains the adaptive concept of the Bayesian methodology but reduces the computational need. Copyright © 2014 John Wiley & Sons, Ltd.     

Indecomposability in inverse limits with set-valued functions

In this paper, we develop a sufficient condition for the inverse limit of upper semi-continuous functions to be an indecomposable continuum. This condition generalizes and extends those of Ingram and Varagona. Additionally, we demonstrate a method of constructing upper semi-continuous functions whose inverse limit has the full projection property.     

Topologically weakly mixing homeomorphisms of the Klein bottle that are uniformly rigid

In this paper we prove that there is a large family of topologically weakly mixing homeomorphisms of the Klein bottle that are uniformly rigid. We do this by viewing the Klein bottle as the quotient of the two-torus by an appropriate group action and producing topologically weakly mixing homeomorphisms of the two-torus that are uniformly rigid and equivariant with respect to the action.