RESUMEN
PURPOSE: This study aims to develop a diagnostic model that combines computed tomography (CT) images and radiomic features to differentiate indeterminate small (5-20 mm) solid pulmonary nodules (SSPNs). METHODS: This study retrospectively enrolled 413 patients who had had SSPNs surgically removed and histologically confirmed between 2017 and 2019. The SSPNs included solid malignant pulmonary nodules (n = 210) and benign pulmonary nodules (n = 203). The least absolute shrinkage and selection operator was used for radiomic feature selection, and random forest algorithms were used for radiomic model construction. The clinical model and nomogram were established using univariate and multivariable logistic regression analyses combined with clinical symptoms, subjective CT findings, and radiomic features. The area under the curve (AUC) of the receiver operating characteristic curve was used to evaluate the performance of the models. RESULTS: The AUC for the clinical model was 0.77 in the training cohort [n = 289; 95% confidence interval (CI): 0.71-0.82; P = 0.001] and 0.75 in the validation cohort (n = 124; 95% CI: 0.66-0.83; P = 0.016). The AUCs for the nomogram were 0.92 (95% CI: 0.89-0.95; P < 0.001) and 0.85 (95% CI: 0.78-0.91; P < 0.001), respectively. The radiomic score (Rad-score), sex, pleural indentation, and age were the independent predictors that were used to build the nomogram. CONCLUSION: The radiomic nomogram derived from clinical features, subjective CT signs, and the Rad-score can potentially identify the risk of indeterminate SSPNs and aid in the patient's preoperative diagnosis.
Asunto(s)
Neoplasias Pulmonares , Humanos , Neoplasias Pulmonares/diagnóstico por imagen , Neoplasias Pulmonares/patología , Nomogramas , Estudios Retrospectivos , Tomografía Computarizada por Rayos X/métodos , Factores de RiesgoRESUMEN
The water-soluble polyacrylamide (PAM) can accumulate in ecosystems and cause serious environmental pollution. Biological approach achieves poor PAM degradation efficiency, due to the extreme resistance of PAM to the microbial metabolism. In the present work, the potential of bioelectrochemical system (BES) as an effective tool to degrade the PAM is adequately evaluated. The closed-circuit operation of BES obtains COD removal efficiencies of 29.2 and 33.6 % for the PAM and polyacrylic acid (PAA), respectively. In comparison, 4.3 and 2.7 % of COD are removed after the PAM and PAA are treated in the open-circuit BES, and 7.3 and 6.6 % are removed in the aerobic BES. These results suggest the bioelectricity generation is crucial to trigger the activity of bioanode for the effective degradation of PAM. Bioelectricity generation not only favors the decomposition of carbon backbone but also facilitates the hydrolysis of amide group in the side-chain of PAM. Microbial attack on the carbon backbone of PAM is proposed to initiate at the head-to-head linkage, resulting in the formation of ether bond within the shortened carbon chain. The Ignavibacterium sp. and phenotypically uncharacterized bacteria are classified as the dominant species on the anode of PAM-fed BES.
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Resinas Acrílicas/metabolismo , Bacteroidetes/metabolismo , Fuentes de Energía Bioeléctrica , Técnicas Electroquímicas/métodos , Contaminantes Químicos del Agua/metabolismo , Purificación del Agua/métodos , Resinas Acrílicas/análisis , Biodegradación Ambiental , Carbono/metabolismo , Electrodos , Hidrólisis , Contaminantes Químicos del Agua/análisisRESUMEN
The wide application of water-soluble linear polyacrylamides (PAMs) can cause serious environmental pollution. Biological treatment of PAMs receives very limited efficiency due to their recalcitrance to the microbial degradation. Here, we show the bioelectrochemical system (BES) can be used as an effective strategy to improve the biodegradation efficiency of PAMs. A linear PAM with viscosity-average molecular weight of 5 × 10(6) was treated in the anodic chamber of BES reactor, and the change of PAM structure during the degradation process was investigated. The anodic bacteria in the BES demonstrated abilities to utilize the PAM as the sole carbon and nitrogen source to generate electricity. Both the anode-attached and planktonic bacteria contributed to the electricity generation, while the anode-attached community exhibited stronger electron transfer ability than the planktonic one. The closed-circuit and open-circuit operations of the BES reactor obtained chemical oxygen demand (COD) removal efficiencies of 32.5 and 7.4 %, respectively, implying the generation of bioelectricity could enhance the biodegradation of PAM. Structure analysis suggested the carbon chain of PAM was partially degraded in the BES, producing polymeric products with lower molecular weight. The microbial cleavage of the carbon chain was proposed to start from the "head-to-head" linkages and end with the formation of ether bonds.
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Resinas Acrílicas/química , Fuentes de Energía Bioeléctrica , Bacterias/metabolismo , Biodegradación Ambiental , Análisis de la Demanda Biológica de Oxígeno , Biomasa , Carbono/metabolismo , Técnicas Electroquímicas , Contaminación Ambiental , Nitrógeno/metabolismoRESUMEN
The chelated-iron process is among the most promising techniques for the hydrogen sulfide (H2S) removal due to its double advantage of waste minimization and resource recovery. However, this technology has encountered the problem of chelate degradation which made it difficult to ensure reliable and economical operation. This work aims to develop a novel fuel-cell-assisted chelated-iron process which employs an air-cathode fuel cell for the catalyst regeneration. By using such a process, sulfur and electricity were effectively recovered from H2S and the problem of chelate degradation was well controlled. Experiment on a synthetic sulfide solution showed the fuel-cell-assisted chelated-iron process could maintain high sulfur recovery efficiencies generally above 90.0%. The EDTA was preferable to NTA as the chelating agent for electricity generation, given the Coulombic efficiencies (CEs) of 17.8 ± 0.5% to 75.1 ± 0.5% for the EDTA-chelated process versus 9.6 ± 0.8% to 51.1 ± 2.7% for the NTA-chelated process in the pH range of 4.0-10.0. The Fe (III)/S(2-) ratio exhibited notable influence on the electricity generation, with the CEs improved by more than 25% as the Fe (III)/S(2-) molar ratio increased from 2.5:1 to 3.5:1. Application of this novel process in treating a H2S-containing biogas stream achieved 99% of H2S removal efficiency, 78% of sulfur recovery efficiency, and 78.6% of energy recovery efficiency, suggesting the fuel-cell-assisted chelated-iron process was effective to remove the H2S from gas streams with favorable sulfur and energy recovery efficiencies.
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Fuentes de Energía Bioeléctrica , Quelantes/química , Sulfuro de Hidrógeno/química , Hierro/química , Aire , Anaerobiosis , Biocombustibles , Reactores Biológicos , Ácido Edético/química , Electrodos , Gases , Concentración de Iones de Hidrógeno , Oxígeno/química , Sulfuros/química , Azufre/químicaRESUMEN
Due to the high redox activity of Fe(II) and its abundance in natural waters, the electro-oxidation of Fe(II) can be found in many air-cathode fuel cell systems, such as acid mine drainage fuel cells and sediment microbial fuel cells. To deeply understand these iron-related systems, it is essential to elucidate the kinetics and mechanisms involved in the electro-oxidation of Fe(II). This work aims to develop a kinetic model that adequately describes the electro-oxidation process of Fe(II) in air-cathode fuel cells. The speciation of Fe(II) is incorporated into the model, and contributions of individual Fe(II) species to the overall Fe(II) oxidation rate are quantitatively evaluated. The results show that the kinetic model can accurately predict the electro-oxidation rate of Fe(II) in air-cathode fuel cells. FeCO3, Fe(OH)2, and Fe(CO3)2(2-) are the most important species determining the electro-oxidation kinetics of Fe(II). The Fe(II) oxidation rate is primarily controlled by the oxidation of FeCO3 species at low pH, whereas at high pH Fe(OH)2 and Fe(CO3)2(2-) are the dominant species. Solution pH, carbonate concentration, and solution salinity are able to influence the electro-oxidation kinetics of Fe(II) through changing both distribution and kinetic activity of Fe(II) species.