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Background: This pilot study aims at exploiting machine learning techniques to extract color Doppler ultrasound (CDUS) features and to build an artificial neural network (ANN) model based on these CDUS features for improving the diagnostic performance of thyroid cancer classification. Methods: A total of 674 patients with 712 thyroid nodules (TNs) (512 from internal dataset and 200 from external dataset) were randomly selected in this retrospective study. We used ANN to build a model (TDUS‐Net) for classifying malignant and benign TNs using both the automatically extracted quantitative CDUS features (whole ratio, intranodular ratio, peripheral ratio, and number of vessels) and gray‐scale ultrasound (US) features defined by the American College of Radiology (ACR) Thyroid Imaging Reporting and Data System (TI‐RADS). Then, we compared the diagnostic performance of the model, the performance of another ANN model based on the gray‐scale US features alone (TUS‐Net), and that of radiologists. Results: The TDUS‐Net (0.898, 95% CI: 0.868–0.922) achieved a higher area under the curve (AUC) than that of TUS‐Net (0.881, 95% CI: 0.850–0.908) in the internal tests. Compared with radiologists, TDUS‐Net (AUC: 0.925, 95% CI: 0.880–0.958) performed better than radiologists (AUC: 0.810, 95% CI: 0.749–0.862) in the external tests. Conclusions: Applying a machine learning model by combining both gray‐scale US features and CDUS features can achieve comparable or even higher performance than radiologists in classifying TNs. [ABSTRACT FROM AUTHOR]

The waterway from Chongqing to Yibin in the upper Yangtze River provides strong support for the socioeconomic development in Western China, while it also has a negative influence on the river ecosystem, such as river fragmentation, wetland disconnectivity, fish habitat, and biodiversity. Accurately characterizing the exploitation, economic efficiency, and ecological pressure of the waterway from Chongqing to Yibin is of great significance for the further development of the upper Yangtze River. In this study, based on statistical data from the National Bureau of Statistics of China, the waterway development, economic benefits, and ecological pressure of the waterway from Chongqing to Yibin were evaluated. The sustainability index (SI) was introduced to comprehensively assess the sustainability of waterways using the hierarchical model, which integrates the exploitation ratio (ER), economic efficiency index (EEI), and ecological pressure index (EPI). A relatively low ER (41.04%), a low consistency index (CI, 0.31), a high EEI (9037.18 USA$/gha), and a low EPI (0.33) yielded an SI of 0.70, indicating that the waterway from Chongqing to Yibin in the upper Yangtze River is in a sustainable development stage. Compared with the typical global Golden Inland Waterways, the waterway from Chongqing to Yibin still has great development potential under the prioritizing ecological protection. [ABSTRACT FROM AUTHOR]

A comprehensive computational fluid dynamic (CFD) model of CEES‐developed polyethylenimine impregnated protonated titanate nanotubes (PEI‐PTNTs) was developed using the Multiphase Flow with Interphase eXchanges (MFiX) package to evaluate the performance of the PEI‐PTNTs in a 1‐MW pilot‐scale carbon capture reactor developed by the National Energy Technology Laboratory (NETL). In this CFD model, the momentum, continuity, and energy transport equations were integrated with the first‐order chemistry model for chemical kinetics of heterogeneous reactions to predict the adsorption of CO2 onto amine‐based sorbent particles and the reactor temperature. Based on the amount of the CO2 adsorption obtained in the small‐scale experiment, the coefficients for the chemical reaction equations of PEI‐PTNTs are adjusted. The adjusted PEI‐PTNTs model is applied to the simplified numerical model of 1‐MW pilot‐scale carbon capture system, which is calibrated through the comparison between our simulation results and the results provided by NETL. This calibrated CFD model is used for selecting the optimized flow rate of the gas phase. Our study shows that the optimized gas flow rate to absorb 100% CO2 without loss is 1.5 kg/s, but if higher absorption rate is preferable despite some loss of CO2 absorption in the reactor, a higher flow rate than 1.5 kg/s can be selected. [ABSTRACT FROM AUTHOR]

Solid absorbents made with polyethylenimine (PEI), which is loaded on different porous substrates, are promising for postcombustion carbon dioxide capture. Herein, theoretical studies of polyamine applications, including PEI for carbon dioxide capture, are reviewed and the development of experimental work on carbon dioxide capture by using PEI summarized. The mechanisms of carbon dioxide capture are discussed at different reaction sites of the polyamines, such as primary, secondary, and tertiary amine groups. Experimental achievements in carbon dioxide capture are investigated by the incorporation of PEI with different support materials, such as mesoporous silica; nanotubes; membranes; and other materials, such as alumina, zeolite, resin, metal-organic frameworks, and glass fibers, through impregnation, grafting, and synthesis. The excellent carbon dioxide capture capacity and great stability of PEI-impregnated nanomaterials highlight PEI as one of the greatest candidates for carbon dioxide capture from flue gas or air. [ABSTRACT FROM AUTHOR]

Combined quantum mechanical calculations and classical molecular dynamics simulations were conducted to investigate the hydration properties of carboxybetaine zwitterion brushes with varying separation distances between the quaternary ammonium cation and carboxylic anion. The brushes consist of zwitterion trimers and are investigated to mimic interacting zwitterion chains grafted on a substrate as well as polymers with interacting zwitterion side chains. Our results show that the values of both positive and negative charges, their separation distances as well as chain interactions appear to play a critical role in the hydration properties of the zwitterions. The overall hydration property of these zwitterions is dictated by the competition between the strong hydration of the charged groups and the dehydration of the hydrocarbon chains. The strongest hydration occurs when the -CH2- unit in the hydrocarbon chain reaches 6-8 for these trimers. Further increase in the hydrocarbon chain length to 10-14 leads to significant and sudden dehydration of the trimers. The water structure and the water residence time surrounding the zwitterions also demonstrate substantial alteration at this length scale. This hydrophilic-to-hydrophobic transition is induced by the hydrophobic interactions of the trimer chains. Our hydration results could explain the observed trend of the superiority of the methylated carbohydrates and poly(ethylene glycol) as antifouling materials compared to corresponding hydroxylterminated compounds. [ABSTRACT FROM AUTHOR]