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Thin films of nc-TiC/ a-C:H nanocornposite have been deposited by reactive magnetron sputtering at substrate bias values of-240 and-91 V. The grain size and grain separation, which together define the nanostructure, are correlated to the amount of the amorphous phase. From the size of the TiC grains measured by x-ray diffraction and the amorphous hydrogenated carbon (a-C:H) phase content determined by x-ray photoelectron spectroscopy, the mean grain separation is estimated using a simple model for the nanostructure. Films deposited at-240 V show a hardness enhancement for a-C:H phase contents in the range 10% to 30% with TiC grain sizes around 5 nm. The mean grain separation for such films was estimated to be 0.3 nm. Films with higher a-C:H phase contents still have 5 nm small grains, but their mean grain separation is larger than 0.5 nm; their hardness is thus determined by the properties of the amorphous matrix. A less pronounced hardness enhancement is observed for films deposited at-91 V. They have larger grains and larger mean gain separations and show smaller hardness values. The hardness of the films, among other mechanical properties, is controlled by the nanostructure. Raman measurements have shown that a-C:H is present in films with mean grain separation down to 0.2 nm. Coefficients of friction against steel lower than 0.3, independent of the substrate bias, are found for films with mean grain separations as low as 0.15 nm. Self-lubrication due to a-C:H can explain the observed friction behavior, although the presence of a-C:H cannot be proved by Raman spectroscopy for films with mean grain sepm•ations smaller than 0.2 nm. It is shown that the substrate bias is crucial in obtaining increased hardness of nc-TiCI a-C:H nanocomposite thin films. In contrast lo the hardness of the coatings, their friction behavior is not affected by the substrate bias.

Titanium aluminum nitride films (Ti 1Ϫx Al x N) have been deposited by reactive magnetron cosputtering. Elemental compositions of these films have been determined by core level photoelectron spectroscopy. Scanning electron microscopy reveals a columnar film growth. This is also reflected by the topography of film surfaces as studied by atomic force microscopy. By x-ray diffraction a crystalline atomic structure is revealed. Single phase samples can be obtained, consisting of the substitutional solid solution ͑Ti, Al͒N. Crystallites show preferential orientation. The optical properties of these films have been investigated by spectrophotometry in the UV-VIS-NIR wavelength range. Depending on the elemental composition, the optical constants vary from metallic to dielectric behavior. For film compositions with xϽ0.5 typical features are a tunable transmission maximum and reflection minimum in the visible spectral range, a high infrared reflection, and a low infrared absorption. Due to these optical properties, Ti 1Ϫx Al x N films are promising candidates for applications such as coatings for solar control windows and optical selective solar absorbers.

for the QABE investigatorsBackground and Purpose-Thrombolysis improves outcome of patients with acute ischemic stroke, but it is unknown whether thrombolysis has a measurable effect on long-term outcome in a defined population. Methods-We prospectively assessed demographic data, management, and outcome of acute ischemic stroke patients admitted within 48 hours to 18 primary care hospitals of the canton of Bern (969 299 inhabitants) during 12 months. Blinded follow-up was obtained at 3 and 12 months. Predictors of mortality and favorable outcome (modified Rankin Scale score Յ2) at 3 and 12 months using logistic regression were analyzed. Results-From December 2007 to December 2008, 807 patients (mean age, 72 years) were included. Median NationalInstitutes of Health Stroke Scale score on admission was 5; 107 patients (13%) received intravenous, intra-arterial, or mechanical thrombolysis. Estimated cumulative mortality at 3 months was 20.6% and at 12 months 27.4%. Age 75 years or older, higher National Institutes of Health Stroke Scale scores, and higher Charlson comorbidity index were independent predictors of mortality at 3 and 12 months. Estimated favorable outcome at 3 months was 48.2% and at 12 months was 44.6%. Thrombolysis was the only modifiable independent predictor of favorable outcome at 3 (relative risk, 1.49; 95% CI, 1.18 -1.89) and 12 months (relative risk, 1.59; 95% CI, 1.24 -2.04), whereas age younger than 75 years, male gender, National Institutes of Health Stroke Scale score Ͻ4, and lower Charlson comorbidity index were nonmodifiable predictors. Conclusions-Thirteen percent of acute ischemic stroke patients admitted within 48 hours to Bernese hospitals underwent thrombolysis, which exerted a measurable effect on 3-month outcome in this population. This effect was sustained at 12 months. Age, stroke severity, Charlson comorbidity index, and male gender were independent nonmodifiable predictors of outcome.