Changes in the structural dimensionality of selenidostannates in ionic liquids: formation, structures, stability, and photoconductivity.

In situ transformations of selenidostannate frameworks in ionic liquids (ILs) were initiated by treatment of the starting phase K2[Sn2Se5] and the consecutive reaction products by means of temperature increase and/or amine addition. Along the reaction pathway, the framework dimensionalities of the five involved selenidostannate anions develop from 3D to 1D and back, both in top-down and bottom-up style. Addition of ethane-1,2-diamine (en) led to the reversion of the 2D→1D step from 2D-{[Sn24Se56](16-)} to 1D-{[Sn6Se14](4-)}.

The optics and performance of dual-focus fluorescence correlation spectroscopy.

Fluorescence correlation spectroscopy (FCS) is an important spectroscopic technique which can be used for measuring the diffusion and thus size of fluorescing molecules at pico- to nanomolar concentrations. Recently, we introduced an extension of conventional FCS, which is called dual-focus FCS (2fFCS) and allows absolute diffusion measurements with high precision and repeatability. It was shown experimentally that the method is robust against most optical and sample artefacts which are troubling conventional FCS measurements, and is furthermore able to yield absolute values of diffusion coefficients without referencing against known standards.

Impact orientation can significantly affect the outcome of a blunt impact to the rabbit patellofemoral joint.

This laboratory has developed a subfracture, joint trauma model in rabbits. Using a dropped impact mass directed onto a slightly abducted joint, chronic softening of retropatellar cartilage and thickening of underlying subchondral bone are documented in studies to 1 year post-insult. It has been hypothesized that these tissue changes are initiated by stresses developed during impact loading.

Chronic changes in rabbit retro-patellar cartilage and subchondral bone after blunt impact loading of the patellofemoral joint.

Animal models of acute joint injury are useful for study of changes in joint tissues that may eventually lead to degradative disease. Our laboratory has developed a joint trauma model using a single blunt impact to the patellofemoral joint of rabbits and documented softening of retro-patellar cartilage and thickening of its underlying bone out to 12 months post-trauma. In the present study, we examined changes in these joint tissues out to 36 months post-impact.