The Karnofsky Performance Scale (KPS) was evaluated in a geriatric outpatient population with regard to three issues: its strength of association with widely used and validated geriatric instruments; its ability to predict patient outcomes; and its ability to serve as an identifier of high-risk patients. The 134-patient sample was given a comprehensive geriatric assessment which included the KPS, the Activities of Daily Living (ADL) scale, the Instrumental Activities of Daily Living (IADL) scale, and other psychosocial and sensory tests. The KPS, ADL, and IADL were significantly correlated with each other, and the KPS showed the strongest associations with other functional measures. The KPS was also highly predictive of outcomes, performing better or equally well as the ADL and IADL. The KPS designation of high- and low-risk groups resulted in statistically significant score differences between groups in all but one assessment area, demonstrating better ability to discriminate than either the ADL or IADL. Thus, the KPS was shown to serve as an effective proxy score for a patient's health and functional status. It also was a significant predictor of hospitalizations, survival time, community residence, and institutionalization. Finally, the KPS was shown to adequately distinguish risk groups to aid in the targeting of services to ambulatory geriatric patients.
The prevalence of visual impairment among elderly patients admitted to hospital is unknown. This group of patients may be particularly at risk from poor vision which could jeopardise their independence. A prospective study of visual impairment and its aetiology in acute geriatric admissions assessed after the acute illness had settled was performed. Subjects were all patients aged 65 years or over, excluding those chronically confused, admitted to the Department of Geriatric Medicine at the Royal Liverpool University Hospital with an acute medical illness. After the acute illness had settled visual impairment, as defined by the American criteria (best acuity 6/18), was assessed on the ward with a Snellen chart read at 6 m using binocular vision and current glasses. Those patients identified with impaired vision on initial screening were formally assessed in the ophthalmology department to identify the cause. 200 patients were examined. 101 patients (50.5%) had impaired vision. In these patients, correctable refractive errors were present in 40%, cataract in 37% and senile macular degeneration in 14%. Of the 101 patients with impaired vision 79% had a reversible cause. Comparing these results with a recent study in the community showed a much higher incidence for patients admitted to hospital. There was a particularly high prevalence in those elderly patients who were admitted with falls (76%, p = 0.0003). In conclusion, elderly patients, especially those presenting with falls, admitted to hospital have a high prevalence of visual impairment. Visual impairment may be compounding or causing falls. Hence, screening the elderly ‘faller’ admitted to hospital for visual impairment may be beneficial to the patient and cost-effective as many of the causes are simply reversible.
We report the synthesis of highly transparent poly(stearyl methacrylate)-poly(2,2,2-trifluoroethyl methacrylate) (PSMA–PTFEMA) diblock copolymer nanoparticles via polymerization-induced self-assembly (PISA) in nonpolar media at 70 °C. This was achieved by chain-extending a PSMA precursor block via reversible addition–fragmentation chain transfer (RAFT) dispersion polymerization of TFEMA in n-tetradecane. This n-alkane has the same refractive index as the PTFEMA core-forming block at 70 °C, which ensures high light transmittance when targeting 33 nm spherical nanoparticles. Such isorefractivity enables visible absorption spectra to be recorded with minimal light scattering even at 30% w/w solids. However, in situ monitoring of the trithiocarbonate RAFT end-groups during PISA requires selection of a weak n → π* band at 446 nm. Conversion of TFEMA into PTFEMA causes a contraction in the reaction solution volume, leading to an initial increase in absorbance that enables the kinetics of polymerization to be monitored via dilatometry. At ∼98% TFEMA conversion, this 446 nm band remains constant for 2 h at 70 °C, indicating surprisingly high RAFT chain-end fidelity (and hence pseudoliving character) under monomer-starved conditions. In situ 19F NMR spectroscopy studies provide evidence for (i) the onset of micellar nucleation, (ii) solvation of the nanoparticle cores by TFEMA monomer, and (iii) surface plasticization of the nanoparticle cores by n-tetradecane at 70 °C. Finally, the kinetics of RAFT chain-end removal can be conveniently monitored by in situ visible absorption spectroscopy: addition of excess initiator at 70 °C causes complete discoloration of the dispersion, with small-angle X-ray scattering studies confirming no change in nanoparticle morphology under these conditions.
Core cross-linked poly(stearyl methacrylate)–poly(benzyl methacrylate)–poly(ethylene glycol dimethacrylate) [S31–B200–E20] triblock copolymer nanoparticles were synthesized directly in an industrial mineral oil via polymerization-induced self-assembly (PISA). Gel permeation chromatography analysis of the S31–B200 diblock copolymer precursor chains indicated a well-controlled reversible addition–fragmentation chain transfer dispersion polymerization, while transmission electron microscopy, dynamic light-scattering (DLS), and small-angle X-ray scattering studies indicated the formation of well-defined spheres. Moreover, DLS studies performed in THF, which is a common solvent for the S and B blocks, confirmed successful covalent stabilization because well-defined solvent-swollen spheres were obtained under such conditions. Tribology experiments using a mini-traction machine (MTM) indicated that 0.50% w/w dispersions of S31–B200–E20 spheres dramatically reduce the friction coefficient of base oil within the boundary lubrication regime. Given their efficient and straightforward PISA synthesis at high solids, such nanoparticles offer new opportunities for the formulation of next-generation ultralow-viscosity automotive engine oils.
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