Analysis of time-of-flight photocurrents in a-Si:H deposited by expanding thermal plasma

The drift mobility of electrons and holes was studied in a standard time-of-flight (TOF) experiment, as a function of temperature and applied electric field, for several series of a-Si:H samples that were deposited at high growth rate in an expanding thermal plasma (ETP) at substrate temperatures near 400°C. Room-temperature electron mobilities are somewhat lower than for standard plasma-enhanced chemical vapor deposited (PECVD) material, but the hole mobility is more than one decade higher. The dispersion of the photocurrent transients is comparable to the one in PECVD samples, but both electron and hole mobilities of the ETP material are remarkably insensitive to the magnitude of applied electric fields in the measured range of 0.1 to 5.0 × 104 V/cm. The temperature dependence of the mobilities, on the contrary, is high, with resolved activation energies of ∼0.24 eV for electrons and ∼0.40 eV for holes. Standard multiple-trapping analysis of the above results in terms of the underlying density of localized states suggests rather wide distributions of tail states on both sides of the gap. To account simultaneously for the weak field dependencies it is necessary to consider non-negligible recombination or deep trapping of the carriers. Measurements and analysis of the post-transit TOF signals do support the presence of a strong deep-trapping component in the transient signal

Early drop in systolic blood pressure and worsening renal function in acute heart failure: Renal results of Pre-RELAX-AHF

Aims We aimed to determine the relation between baseline systolic blood pressure (SBP), change in SBP, and worsening renal function (WRF) in acute heart failure (AHF) patients enrolled in the Pre-RELAX-AHF trial. Methods and resultsThe Pre-RELAX-AHF study enrolled 234 patients within 16 h of admission (median 7 h) for AHF and randomized them to relaxin given intravenous (i.v.) for 48 h or placebo. Blood pressure was measured at baseline, at 3, 6, 9, 12, 24, 36, and 48 h and at 3, 4, and 5 days after enrolment. Worsening renal function was defined as a serum creatinine increase of <0.3 mg/dL by Day 5. Worsening renal function was found in 68 of the 225 evaluable patients (30). Patients with WRF were older (73.5 ± 9.4 vs. 69.1 ± 10.6 years; P 0.003), had a higher baseline SBP (147.3 ± 19.9 vs. 140.8 ± 16.7 mmHg; P 0.01), and had a greater early drop in SBP (37.9 ± 16.0 vs. 31.4 ± 12.2 mmHg; P 0.004). In a multivariable model, higher age, higher baseline creatinine, and a greater early drop in SBP, but not baseline SBP, remained independent predictors of WRF. Furthermore, WRF was associated with a higher Day 60 (P 0.01), and Day 180 (P 0.003) mortality. ConclusionsWorsening renal function in hospitalized AHF patients is related to a poor clinical outcome and is predicted by a greater early drop in SBP. © 2011 The Author