Nurses' perceptions of aids and obstacles to the provision of optimal end of life care in ICU

Contains fulltext : 172380.pdf (publisher's version ) (Open Access

Controlling solubility of polymeric anions in supramolecular assemblies with poly(aniline) for microsensors and actuators in human tissue

The supramolecular assembly of poly(aniline) and poly(vinylsulfonate) (PAni/PVS) represents a particularly suitable catalytic material for oxidation of Vitamin C in sensor applications. PAni/PVS assemblies were prepared on platinum at increasing deoxygenation levels (LD ? MD ? HD) and in two thickness sizes of 2 ?m (thick) and 200 nm (thin). Thick HD disks with diameters of 500 ?m and 2 ?m were stable over 90 min in a stirred buffer solution at pH 7 containing 300 ?M Vitamin C. Stirring stability was lost after storage in air, but not after storage under argon. In MD disks PVS was partly lost after 3 h exposure to unstirred neutral buffer solution. Loss could be significantly reduced by oxidative enforcement with ferulic acid (F), a precursor of plant lignin. Application of elliptical F-PAni/PVS microelectrodes with diameters of 20 ?m × 30 ?m in brain parenchyma of rats showed surprisingly weak influence of intraperitoneal Vitamin C injections on the brain tissue level of Vitamin C. After 3 h of tissue exposure poly(aniline) redox activity in acidic solution decreased slightly. Factors which caused enhanced PVS solubility are discussed in detail.<br/

Promoting game theory techniques for targeted advertisements for Social TV business models

In this work the authors assess the main stakeholders involved in using Internet Protocol Television (IPTV) from the perspective of how users can interact in a business model that will be mutually beneficial to all. Then, Social TV is well placed to leverage the benefits to both business players and end users in an advertising business model that will be summarized by authors using game theory techniques

High loading of single atomic iron sites in Fe-NC oxygen reduction catalysts for proton exchange membrane fuel cells

Non-precious iron-based catalysts (Fe-NCs) require high active site density (SD) to meet the performance targets as cathode catalysts in proton exchange membrane fuel cells (PEMFCs). SD is generally limited to that achieved at 1-3 wt%(Fe) loading due to the undesired formation of iron-containing nanoparticles at higher loadings. Here we show that by pre-forming a carbon-nitrogen matrix using a sacrificial metal (Zn) in the initial synthesis step and then exchanging iron into this preformed matrix we achieve 7 wt% iron coordinated solely as single atom Fe-N4 sites as identified by 57Fe cryo Mössbauer spectroscopy and X-ray absorption spectroscopy. SD values measured by in situ nitrite stripping and ex situ CO chemisorption methods are 4.7x1019 and 7.8x1019 sitesg-1, with a turnover frequency of 5.4 electrons̭sites-1s-1 at 0.80 V in 0.5M H2SO4 electrolyte. The catalyst delivers excellent PEMFC performance with current densities of 41.3 mAcm-2 at 0.90 ViR-free using H2-O2 (10.6 Ag-1) and 145 mA cm-2 at 0.80 V (199 mAcm-2 at 0.80 ViR-free) using H2-air

Controlling Near-Surface Ni Composition in Octahedral PtNi(Mo) Nanoparticles by Mo Doping for a Highly Active Oxygen Reduction Reaction Catalyst

We report and study the translation of exceptionally high catalytic oxygen electroreduction activities of molybdenum-doped octahedrally shaped PtNi(Mo) nanoparticles from conventional thin-film rotating disk electrode screenings (3.43 ± 0.35 A mgPt–1 at 0.9 VRHE) to membrane electrode assembly (MEA)-based single fuel cell tests with sustained Pt mass activities of 0.45 A mgPt–1 at 0.9 Vcell, one of the highest ever reported performances for advanced shaped Pt alloys in real devices. Scanning transmission electron microscopy with energy dispersive X-ray analysis (STEM-EDX) reveals that Mo preferentially occupies the Pt-rich edges and vertices of the element-anisotropic octahedral PtNi particles. Furthermore, by combining in situ wide-angle X-ray spectroscopy, X-ray fluorescence, and STEM-EDX elemental mapping with electrochemical measurements, we finally succeeded to realize high Ni retention in activated PtNiMo nanoparticles even after prolonged potential-cycling stability tests. Stability losses at the anodic potential limits were mainly attributed to the loss of the octahedral particle shape. Extending the anodic potential limits of the tests to the Pt oxidation region induced detectable Ni losses and structural changes. Our study shows on an atomic level how Mo adatoms on the surface impact the Ni surface composition, which, in turn, gives rise to the exceptionally high experimental catalytic ORR reactivity and calls for strategies on how to preserve this particular surface composition to arrive at performance stabilities comparable with state-of-the-art spherical dealloyed Pt core–shell catalysts

A large-scale collaborative effort for noise-robust speaker verification

Contains fulltext : 116114.pdf (author's version ) (Open Access)Interspeech 2013, 25 augustus 201