The Investigation of Suspected Fracture-a Comparison of Ultrasound With Conventional Imaging.

Background: Ultrasound imaging can be used to diagnose fractures in patients with acute trauma. Its main advantages over conventional imaging are the absence of radiation exposure and its greater availability.

Methods: A systematic search in electronic databases (Medline, Embase, Cochrane CENTRAL) was supplemented by a manual search on the Internet and in the reference lists of pertinent publications.

Diffusion-limited energy transfer in blends of oligofluorenes with an anthracene derivative.

Organic semiconductor devices such as light-emitting diodes and solar cells frequently comprise a blend of molecular or polymeric materials. Consequently, resonant energy transfer between the components plays a major role in determining device performance. Energy transfer may take place through either single-step donor-acceptor transfer, realized for example as Förster transfer, or as a sequence of donor-donor transfers toward the acceptor site.

The influence of π-π-stacking on the light-harvesting properties of perylene bisimide antennas that are covalently linked to a [60]fullerene.

A flexible organic triad consisting of two perylene bisimide antennas covalently linked to a [60]fullerene by flexible spacers has been synthesized and studied by electrochemistry, steady-state and time-resolved spectroscopy. We found that π-π-stacking of the two antenna subunits has considerable impact on the photophysics of the system and leads to a reduction of the effective light-harvesting efficiency of the assembly. This finding is important for light harvesting in flexible materials based on the dye antenna-fullerene concept.

Mutual interplay of light harvesting and triplet sensitizing in a perylene bisimide antenna-fullerene dyad.

A flexible organic dyad consisting of a perylene bisimide antenna covalently linked to a [60]fullerene has been synthesized and studied by electrochemistry, steady-state spectroscopy, and time-resolved spectroscopy. We found that the energy absorbed by the perylene bisimide is transferred to the fullerene with an efficiency close to 100%. The fullerene in turn undergoes intersystem crossing followed by triplet energy transfer back to the perylene bisimide with an efficiency of at least 20%.

Energy- and charge-transfer processes in flexible organic donor-acceptor dyads.

Organic donor-bridge-acceptor dyads consisting of a triphenyldiamine donor that was linked to a perylenebisimide acceptor by a flexible nonconjugated bridge have been investigated by complementary spectroscopic techniques as a function of the length and the polarity of the linker. Time-resolved fluorescence spectroscopy revealed a quenching of the donor emission accompanied by a corresponding rise in the acceptor fluorescence, which indicates an efficient energy transfer between the donor and acceptor moieties. A second fluorescence quenching process that affects the acceptor emission is ascribed to a ground-state electron transfer from the donor to the acceptor.