Structural, dynamic and photophysical properties of a fluorescent dye incorporated in an amorphous hydrophobic polymer bundle.

The properties of a low molecular weight organic dye, namely 4-naphthyloxy-1-methoxy-2,2,6,6-tetramethylpiperidine, covalently bound to an apolar polyolefin were investigated by means of a multi-level approach, combining classical molecular dynamics simulations, based on purposely parameterized force fields, and quantum mechanical calculations based on density functional theory (DFT) and its time-dependent extension (TD-DFT). The structure and dynamics of the dye in its embedding medium were analyzed and discussed taking the entangling effect of the surrounding polymer into account, and also by comparing the results to those obtained for a different environment, i.e. toluene solution. Finally, the influence was investigated of long lived cages found in the polymeric embedding on photophysical properties, in terms of the slow and fast dye's internal dynamics, by comparing computed IR and UV spectra with their experimental counterparts.

Clinical effects of betamethasone and hyaluronan, and of defocalized carbon dioxide laser treatment on traumatic arthritis in the fetlock joints of horses.

The clinical effects of intra-articular betamethasone together with hyaluronan (betaM/HA) and treatment with a defocalized carbon dioxide laser on acute traumatic arthritis of the fetlock joint were assessed. The horses in these studies were selected using a thorough lameness examination, including intra-articular anaesthesia abolishing the lameness. This investigation comprised an observer-blind study, including 10 sport horses (10 joints), and a prospective study, including 180 sport horses (333 joints). In both studies, the material was divided into two groups treated with either betaM/HA or a carbon dioxide laser. The treatment doses were 12 mg of betaM, 20 mg of HA or 60 J/cm2 of treated area. Convalescence before training was 21 days for both groups in the observer-blind study. In the prospective study, convalescence in the betaM/HA group was 21 days but was only 7 days for the laser-treated group. In the observer-blind study, three of five treated joints recovered in both cohorts. In the prospective study, the groups had significantly different recovery rates--68% of the betaM/HA-treated joints and 80% of the carbon dioxide laser-treated joints. These results indicate that the defocalized carbon dioxide laser should be an applicable mode of treatment of acute traumatic synovitis in horses. However, the biochemical functions related to carbon dioxide laser treatment require further elucidation.