https://www.selleckchem.com/products/itd-1.html Double-gate tunnel field-effect transistor (DG TFET) is expected to extend the limitations of leakage current and subthreshold slope. However, it also suffers from the ambipolar behavior with the symmetrical source/drain architecture. To overcome the ambipolar current, asymmetry must be introduced between the source and drain. In this paper, we investigate the performances of DG TFET with step channel thickness (SC TFET) by utilizing the 2D simulation. The asymmetry between source and drain is introduced through the step channel thickness; hence, the ambipolar behavior is expected to be relieved. The results show that the SC TFET exhibits significant reduction of ambipolar current compared with the conventional DG TFET. The mechanisms of SC TFET are thoroughly discussed to explore the physical insight. The impacts introduced by the structure parameters on onset voltage, subthreshold slope, drain current in on-state and ambipolar-state are also exhibited in determining the optimal structure.Background Block-sequential regularized expectation maximization (BSREM) is a fully convergent iterative image reconstruction algorithm. We hypothesize that tracers with different distribution patterns will result in different optimal settings for the BSREM algorithm. The aim of this study was to evaluate the image quality with variations in the applied β-value and acquisition time for three positron emission tomography (PET) tracers. NEMA image quality phantom measurements and clinical whole-body digital time-of-flight (TOF) PET/computed tomography (CT) examinations with 68Ga-DOTATOC (n = 13), 18F-fluoride (n = 10), and 11C-acetate (n = 13) were included. Each scan was reconstructed using BSREM with β-values of 133, 267, 400, and 533, and ordered subsets expectation maximization (OSEM; 3 iterations, 16 subsets, and 5-mm Gaussian post-processing filter). Both reconstruction methods included TOF and point spread function (PSF) recover