Harry L Anderson — Page 2

PubMed2002

Cyclodextrin-threaded conjugated polyrotaxanes as insulated molecular wires with reduced interstrand interactions.

Control of intermolecular interactions is crucial to the exploitation of molecular semiconductors for both organic electronics and the viable manipulation and incorporation of single molecules into nano-engineered devices. Here we explore the properties of a class of materials that are engineered at a supramolecular level by threading a conjugated macromolecule, such as poly(para-phenylene), poly(4,4'-diphenylene vinylene) or polyfluorene through alpha- or beta-cyclodextrin rings, so as to reduce intermolecular interactions and solid-state packing effects that red-shift and partially quench the luminescence. Our approach preserves the fundamental semiconducting properties of the conjugated wires, and is effective at both increasing the photoluminescence efficiency and blue-shifting the emission of the conjugated cores, in the solid state, while still allowing charge-transport. We used the polymers to prepare single-layer light-emitting diodes with Ca and Al cathodes, and observed blue and green emission. The reduced tendency for polymer chains to aggregate allows solution-processing of individual polyrotaxane wires onto substrates, as revealed by scanning force microscopy.

Cyclodextrins↗

PubMedDate not supplied

Adrenal gland trauma is associated with high injury severity and mortality.

PURPOSE: To review a statewide experience of adrenal gland trauma (AGT), incidence, demographics, associated injuries, Injury Severity Score (ISS), Glasgow Coma Scale (GCS), mechanisms of injury, and complications, associated with AGT. METHODS: A retrospective analysis of patients admitted to accredited trauma centers in the Commonwealth of Pennsylvania who sustained AGT from January 1, 1989 to December 31, 2000. RESULTS: Adrenal trauma was found in 322 of 210,508 cases (0.15%). There were 76.4% men and 23.6% women. Seventy-one percent of patients had an ISS greater than 20. The overall mortality was 32.6%. The mechanism of injury was blunt in 81.4% of the cases and penetrating in 18.6%. Vehicular accidents constituted 48.8% of the cases. Younger age was associated with male predominance and greater proportion of penetrating injuries. Although exact indications are not known, advanced imaging studies were done in 163 of 322 (50.6%) patients: computed tomography in 133 (41.3%), ultrasound in 26 (8.1%), and angiography in 4 cases (1.2%). Exploratory laparotomy was done in 60 (18.6%), splenectomy in 25 (7.8%), nephrectomy in 14 (4.3%), and adrenalectomy in 8 (2.5%). Penetrating injuries had a 43.8% rate of exploratory laparotomy, whereas it was 12.4% in blunt trauma. Associated injuries included liver injury (57.8%), rib fractures (50.9%), kidney injury (41.3%), and spleen injury (32.9%). Pulmonary complications were most common, followed by infection/sepsis, and cardiovascular. Nearly 45% of patients were discharged home, 17% of patients were discharged to a rehabilitation facility, and 3.4% to nursing homes. CONCLUSIONS: Adrenal gland trauma is a rare and largely coincidental finding diagnosed either during an initial radiologic examination or surgical exploration for other injuries. Surgical exploration was carried out in 21.4% of patients, with adrenalectomy in 2.5% of cases and nephrectomy in 4.3% of cases. Adrenal injury is associated with high injury severity, and with mortality rates up to 5 times higher than non-AGT trauma.

Adolescent↗