Structure, Optical Properties, and Photocatalytic Activity towards H 2

High quality single crystalline GaN nanowires with large aspect ratio (>100) are synthesized on n-type Si (111) substrate via Au-catalyzed vapor-liquid-solid process. Morphology, crystal structure, and optical property of the as-synthesized GaN nanowires are characterized by means of X-ray diffraction, scanning/transmission electron microscopy, UV-vis diffuse reflection spectroscopy, and room temperature photoluminescence. The results indicate that the as-prepared GaN nanowires with a large aspect ratio are well crystallized in the hexagonal wurtzite structure, and a slight blue shift appears in both the absorption edge and emission peak probably due to the quantization effect. Photocatalytic H2 evolution over the as-prepared GaN nanowires is performed with the incorporation of Pt or Rh as the cocatalyst, exhibiting greatly enhanced capability compared to the GaN powder tested under the same conditions. Moreover, photocatalytic CO2 reduction over the GaN nanowires is also successfully realized using Pt or Rh as the cocatalyst, depending on which the products show a strong selectivity inherently related to the reductive electrons transferred by cocatalyst

Value of contrast-enhanced CT based radiomic machine learning algorithm in differentiating gastrointestinal stromal tumors with KIT exon 11 mutation: a two-center study

PURPOSEKnowing the genetic phenotype of gastrointestinal stromal tumors (GISTs) is essential for patients who receive therapy with tyrosine kinase inhibitors. The aim of this study was to develop a radiomic algorithm for predicting GISTs with KIT exon 11 mutation.METHODSWe enrolled 106 patients (80 in the training set, 26 in the validation set) with clinicopathologically confirmed GISTs from two centers. Preoperative and postoperative clinical characteristics were selected and analyzed to construct the clinical model. Arterial phase, venous phase, delayed phase, and tri-phase combined radiomics algorithms were generated from the training set based on contrast-enhanced computed tomography (CE-CT) images. Various radiomics feature selection methods were used, namely least absolute shrinkage and selection operator (LASSO); minimum redundancy maximum relevance (mRMR); and generalized linear model (GLM) as a machine-learning classifier. Independent predictive factors were determined to construct preoperative and postoperative radiomics nomograms by multivariate logistic regression analysis. The performances of the clinical model, radiomics algorithm, and radiomics nomogram in distinguishing GISTs with the KIT exon 11 mutation were evaluated by area under the curve (AUC) of the receiver operating characteristics.RESULTSOf 106 patients who underwent genetic analysis, 61 had the KIT exon 11 mutation. The combined radiomics algorithm was found to be the best prediction model for differentiating the expression status of the KIT exon 11 mutation (AUC = 0.836; 95% confidence interval [CI], 0.640-0.951) in the validation set. The clinical model, and preoperative and postoperative radiomics nomograms had AUCs of 0.606 (95% CI, 0.397-0.790), 0.715 (95% CI, 0.506-0.873), and 0.679 (95% CI, 0.468-0.847), respectively, with the validation set.CONCLUSIONThe radiomics algorithm could distinguish GISTs with the KIT exon 11 mutation based on CE-CT images and could potentially be used for selective genetic analysis to support the precision medicine of GISTs

Hierarchical nanowire arrays based on carbon nanotubes and Co3O4 decorated ZnO for enhanced photoelectrochemical water oxidation

A highly enhanced activity for photoelectrochemical water splitting was achieved by fabricating carbon nanotube (CNT) and Co3O4 decorated hierarchical ZnO nanowire (NW) arrays via a facile stepwise synthesis strategy. The ternary CNT-ZnO-Co3O4 NW composite exhibits an increased photocurrent density (1.9 mA cm(-2) at 0.6 V vs. Ag/AgCl, 2.7 times larger than that of the pristine ZnO NWs) and improved incident photon to current conversion efficiency (52.5% at 340 nm, 5.1 times higher than that of the pristine ZnO NWs) as a photoanode under AM 1.5G simulated sunlight. This enhancement is attributed to the specific heterogeneous ternary architecture, which results in promoted electron-hole charge separation and transfer, decreased water oxidation overpotential as well as increased reaction rates of water splitting by decorating ZnO NWs with CNTs and Co3O4

In situ synthesis of ordered mesoporous Co-doped TiO2 and its enhanced photocatalytic activity and selectivity for the reduction of CO2

Ordered mesoporous cobalt-doped titanium dioxide was successfully synthesized by a multicomponent self-assembly process. The doped Co species change the construction of the conduction band and valence band of TiO2, leading to visible-light absorption for TiO2. The designed cobalt-doped titanium dioxide exhibits a higher visible light activity for the reduction of CO2 among the commonly reported photocatalysts. In addition, the selectivity of the reduction products is improved by optimizing the energy-band configurations of cobalt-doped titanium dioxide through varying the molar ratio of Co/Ti. When the doping content of cobalt species increases to some extent, Co3O4/Co-doped TiO2 nanocomposites with oxygen vacancies were obtained, which markedly improve the generation rate of CH4