ABSTRACT
Though local structures in ionic liquids are dominated by strong Coulomb forces, directional hydrogen bonds can also influence the physicochemical properties of imidazolium-based ionic liquids. In particular, the C-2 position of the imidazolium cation is acidic and can bind with suitable hydrogen bond acceptor sites of molecular solvents dissolved in imidazolium-based ionic liquids. In this report, we identify hydrogen-bonded microenvironments of the model ionic liquid, 1-ethyl-3-methylimidazolium tris(pentafluoroethyl) trifluorophosphate, and the changes that occur when molecular solvents are dissolved in it by using a C-D infrared reporter at the C-2 position of the cation. Our linear and nonlinear infrared experiments, along with computational studies, indicate that the molecular solvent dimethyl sulfoxide can form strong hydrogen-bonded dimers with the cation of the ionic liquid at the C-2 position. In contrast, acetone, which is also a hydrogen bond acceptor similar to dimethyl sulfoxide, does not show evidence of cation-solvent hydrogen-bonded conformers at the C-2 position. The outcome of our study on a broad scale strengthens the importance of cation-solute interactions in ionic liquids.
ABSTRACT
AIMS: To examine whether stroke care processes and outcomes are improved following the institution of an acute stroke unit (ASU) at a medium-sized New Zealand hospital. METHODS: Two retrospective audits over 12-month periods were carried out at Hutt Valley Hospital before and after the institution of a 6-bed ASU. Data was collected on demographics, length of stay, stroke type, investigations, processes of care and outcomes. RESULTS: 139 strokes pre ASU and 155 strokes post ASU were studied. 86.8% of strokes received stroke unit care in the 2009 audit. There were more intracerebral haemorrhages in 2006 (17.2% vs. 9.0%). Significant improvements were seen between 2006 and 2009 in time to aspirin administration (52.7 versus 14.5 hours), swallow assessment within 24 hours (88.5% versus 96.1%), lag time to carotid Doppler studies (21 days versus 4.5 days), pressure risk assessments (19.6%, versus 87.2%) and urinary infection rates (10.8% versus 2.0% ). Total length of stay (TLOS) and mortality were reduced but the difference was not statistically significant. (20.5 days versus 18.3 days p=0.34, Inpatient mortality 16.2% versus 10% p=0.12). CONCLUSIONS: The introduction of an ASU has resulted in improvements in several key processes of stroke care. Overall mortality and total length of stay showed a trend to improvement after the establishment of an ASU.
