Search

MRI-guided radiotherapy systems enable beam gating by tracking the target on planar, two-dimensional cine images acquired during treatment. This study aims to evaluate how deep-learning (DL) models for target tracking that are trained on data from one fraction can be translated to subsequent fractions. Cine images were acquired for six patients treated on an MRI-guided radiotherapy platform (MRIdian, Viewray Inc.) with an onboard 0.35 T MRI scanner. Three DL models (U-net, attention U-net and nested U-net) for target tracking were trained using two training strategies: (1) uniform training using data obtained only from the first fraction with testing performed on data from subsequent fractions and (2) adaptive training in which training was updated each fraction by adding 20 samples from the current fraction with testing performed on the remaining images from that fraction. Tracking performance was compared between algorithms, models and training strategies by evaluating the Dice similarity coefficient (DSC) and 95% Hausdorff Distance (HD95) between automatically generated and manually specified contours. The mean DSC for all six patients in comparing manual contours and contours generated by the onboard algorithm (OBT) were 0.68 ± 0.16. Compared to OBT, the DSC values improved 17.0 − 19.3% for the three DL models with uniform training, and 24.7 − 25.7% for the models based on adaptive training. The HD95 values improved 50.6 − 54.5% for the models based on adaptive training. DL-based techniques achieved better tracking performance than the onboard, registration-based tracking approach. DL-based tracking performance improved when implementing an adaptive strategy that augments training data fraction-by-fraction. [ABSTRACT FROM AUTHOR]

Finite control set model predictive control (FCS-MPC) strategy for power converter system outputs single optimal vector by vector ergodic optimization algorithm, with flaws of low vector control accuracy, unfixed switching frequency and high computational burden for microprocessor. In this paper, a hybrid vector and sector model predictive control (HVS-MPC) strategy is proposed for medium and small power converter systems with high control frequency to improve system performance on three aspects. First, a sector optimization algorithm is adopted to reduce computational burden according to radiation range of basic vector and sector location of target vector. Second, a vector synthesis algorithm is adopted in linear modulation area to improve vector control accuracy with fixed switching frequency by vector operation time calculation and sequence setting. Third, in order to improve system performance in over modulation area without extra computational burden, the hybrid vector modulation algorithm is proposed based on target vector length and modulation area. Finally, the proposed strategy is verified through experiment and simulation. [ABSTRACT FROM AUTHOR]

Dye-sensitized photoelectrodes consisting of photosensitizers and molecular catalysts with tunable structures and adjustable energy levels are attractive for low-cost and eco-friendly solar-assisted synthesis of energy rich products. Despite these advantages, dye-sensitized NiO photocathodes suffer from severe electron-hole recombination and facile molecule detachment, limiting photocurrent and stability in photoelectrochemical water-splitting devices. In this work, we develop an efficient and robust biohybrid dye-sensitized NiO photocathode, in which the intermolecular charge transfer is enhanced by a redox polymer. Owing to efficient assisted electron transfer from the dye to the catalyst, the biohybrid NiO photocathode showed a satisfactory photocurrent of 141±17 μA·cm−2 at neutral pH at 0 V versus reversible hydrogen electrode and a stable continuous output within 5 h. This photocathode is capable of driving overall water splitting in combination with a bismuth vanadate photoanode, showing distinguished solar-to-hydrogen efficiency among all reported water-splitting devices based on dye-sensitized photocathodes. These findings demonstrate the opportunity of building green biohybrid systems for artificial synthesis of solar fuels. A robust and efficient dye-sensitized NiO bio-hybrid photocathode based on a redox polymer and [FeFe]- hydrogenase has been developed to couple with a BiVO4 photoanode for water splitting without applied bias. [ABSTRACT FROM AUTHOR]

This document is a correction notice for an article titled "Identification of a Kavain Analog with Efficient Anti-inflammatory Effects" published in Scientific Reports. The original article contained errors in Figure 5C, where an image belonging to a different dataset partially overlapped with the corresponding panel. The corrected figure and legend have been provided. Additionally, there was an error in the Materials and Methods section regarding the age of the mice used in the study, which has been corrected. The authors of the article are Olivier Huck, Xiaxian Han, Hannah Mulhall, Iryna Gumenchuk, Bin Cai, James Panek, Radha Iyer, and Salomon Amar. [Extracted from the article]

A universal strategy for a rapid colorimetric method for Hg2+ in an aqueous solution is described. The specific binding of Hg2+ (thymine-Hg2+-thymine) with thiolated DNA-functionalized gold nanoparticles (AuNPs) via Au–S bonds increases the spatial hindrance of the AuNP surface, resulting in a weakened catalytic ability of AuNPs to catalyze the reaction between p-nitrophenol and NaBH4. Therefore, the color change time (CCT) of the solution from yellow to colorless becomes longer. Based on the kinetic curve of absorbance over time measured by a UV spectrometer, the level of Hg2+ in aqueous solutions can be easily quantified. A linear relationship between CCT and Hg2+ concentration was obtained in the 10–600-nM range with a detection limit of 0.20 nM, which is much lower than the limit value (10 nM) defined by the US Environmental Protection Agency for Hg2+ in drinking water. The excellent sensitivity comes from CCT as the signal output of the probe, rather than the absorbance or wavelength change used in traditional colorimetric probes as the signal output. [ABSTRACT FROM AUTHOR]