Characterization of Thin p-on-p Radiation Detectors with Active Edges

Active edge p-on-p silicon pixel detectors with thickness of 100 $\mu$m were fabricated on 150 mm Float zone silicon wafers at VTT. By combining measured results and TCAD simulations, a detailed study of electric field distributions and charge collection performances as a function of applied voltage in a p-on-p detector was carried out. A comparison with the results of a more conventional active edge p-on-n pixel sensor is presented. The results from 3D spatial mapping show that at pixel-to-edge distances less than 100 $\mu$m the sensitive volume is extended to the physical edge of the detector when the applied voltage is above full depletion. The results from a spectroscopic measurement demonstrate a good functionality of the edge pixels. The interpixel isolation above full depletion and the breakdown voltage were found to be equal to the p-on-n sensor while lower charge collection was observed in the p-on-p pixel sensor below 80 V. Simulations indicated this to be partly a result of a more favourable weighting field in the p-on-n sensor and partly of lower hole lifetimes in the p-bulk.Comment: 23 pages, 16 figures, 1 tabl

Technical note : Comparison of methane ebullition modelling approaches used in terrestrial wetland models

Emission via bubbling, i.e. ebullition, is one of the main methane (CH4) emission pathways from wetlands to the atmosphere. Direct measurement of gas bubble formation, growth and release in the peat-water matrix is challenging and in consequence these processes are relatively unknown and are coarsely represented in current wetland CH4 emission models. In this study we aimed to evaluate three ebullition modelling approaches and their effect on model performance. This was achieved by implementing the three approaches in one process-based CH4 emission model. All the approaches were based on some kind of threshold: either on CH4 pore water concentration (ECT), pressure (EPT) or free-phase gas volume (EBG) threshold. The model was run using 4 years of data from a boreal sedge fen and the results were compared with eddy covariance measurements of CH4 fluxes. Modelled annual CH4 emissions were largely unaffected by the different ebullition modelling approaches; however, temporal variability in CH4 emissions varied an order of magnitude between the approaches. Hence the ebullition modelling approach drives the temporal variability in modelled CH4 emissions and therefore significantly impacts, for instance, high-frequency (daily scale) model comparison and calibration against measurements. The modelling approach based on the most recent knowledge of the ebullition process (volume threshold, EBG) agreed the best with the measured fluxes (R-2 = 0.63) and hence produced the most reasonable results, although there was a scale mismatch between the measurements (ecosystem scale with heterogeneous ebullition locations) and model results (single horizontally ho-mogeneous peat column). The approach should be favoured over the two other more widely used ebullition modelling approaches and researchers are encouraged to implement it into their CH4 emission models.Peer reviewe

Revealing sources of CH4 in a boreal upland forest

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Revealing sources of biological methane production in boreal upland forests

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Everolimus-induced pneumonitis associates with favourable outcome in patients with metastatic renal cell carcinoma

Background: Mammalian target of rapamycin inhibitors may induce pneumonitis. We analysed the association of pneumonitis with outcomes in everolimus treated metastatic renal cell carcinoma (mRCC) patients. Patients and methods: Eighty-five mRCC patients received everolimus at Helsinki University Hospital (cohort A). Computed tomography (CT) verified pneumonitis was correlated with outcome using Kaplan-Meier, Cox regression and logistic regression. An independent cohort of 148 everolimus treated mRCC patients (cohort B) at Aarhus University Hospital was assessed for validation. Results: In cohort A, CT-verified pneumonitis (N = 29, 34.1%) was associated with improved overall survival (OS) (24.7 versus 8.5 months; P <0.001), progression-free survival (PFS) (5.5 versus 3.2 months; P = 0.002) and clinical benefit rate (CBR) 57.1% versus 24.1% (P = 0.003). In multivariate analyses pneumonitis was associated with improved OS (hazard ratio [HR], 0.22; 95% confidence interval [CI] 0.12-0.44; P <0.001), PFS (HR 0.37; 95% CI 0.21-0.66; P = 0.001) and CBR (odds ratio [OR] 4.11; 95% CI 1.42-11.95; P = 0.01). In cohort B, CT-verified pneumonitis (N = 29, 19.6%) was associated with improved OS (12.9 versus 6.0 months; P = 0.02), PFS (6.0 versus 2.8 months; P = 0.02) and CBR (79.3% versus 39.5%; P <0.001). In multivariate analyses pneumonitis was associated with improved OS (HR 0.58; 95% CI 0.36-0.94; P = 0.03), PFS (HR 0.61; 95% CI 0.39-0.95; P = 0.03) and CBR (OR 5.65; 95% CI 2.10-15.18; P = 0.001). In a combined multivariate analysis (N = 233), with pneumonitis as a time-dependent covariate, CT-verified pneumonitis was associated with longer OS (HR, 0.67; 95% CI 0.46-0.97; P = 0.03). Furthermore, in a landmark analysis, pneumonitis was associated with longer OS (17.4 versus 7.8 months; P = 0.01). Conclusions: Everolimus-induced pneumonitis is associated with improved outcome in patients with mRCC and may serve as a biomarker of everolimus efficacy. (C) 2017 Elsevier Ltd. All rights reserved.Peer reviewe