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BACKGROUND: A previously trained deep learning-based smartphone app provides an artificial intelligence solution to help diagnose biliary atresia from sonographic gallbladder images, but it might be impractical to launch it in real clinical settings. This study aimed to redevelop a new model using original sonographic images and their derived smartphone photos and then test the new model's performance in assisting radiologists with different experiences to detect biliary atresia in real-world mimic settings. METHODS: A new model was first trained retrospectively using 3659 original sonographic gallbladder images and their derived 51,226 smartphone photos and tested on 11,410 external validation smartphone photos. Afterward, the new model was tested in 333 prospectively collected sonographic gallbladder videos from 207 infants by 14 inexperienced radiologists (9 juniors and 5 seniors) and 4 experienced pediatric radiologists in real-world mimic settings. Diagnostic performance was expressed as the area under the receiver operating characteristic curve (AUC). RESULTS: The new model outperformed the previously published model in diagnosing BA on the external validation set (AUC 0.924 vs 0.908, P = 0.004) with higher consistency (kappa value 0.708 vs 0.609). When tested in real-world mimic settings using 333 sonographic gallbladder videos, the new model performed comparable to experienced pediatric radiologists (average AUC 0.860 vs 0.876) and outperformed junior radiologists (average AUC 0.838 vs 0.773) and senior radiologists (average AUC 0.829 vs 0.749). Furthermore, the new model could aid both junior and senior radiologists to improve their diagnostic performances, with the average AUC increasing from 0.773 to 0.835 for junior radiologists and from 0.749 to 0.805 for senior radiologists. CONCLUSIONS: The interpretable app-based model showed robust and satisfactory performance in diagnosing biliary atresia, and it could aid radiologists with limited experiences to improve their diagnostic performances in real-world mimic settings.
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Atresia Biliar , Aplicaciones Móviles , Lactante , Niño , Humanos , Vesícula Biliar/diagnóstico por imagen , Inteligencia Artificial , Atresia Biliar/diagnóstico por imagen , Estudios Retrospectivos , RadiólogosRESUMEN
CO2 methanation has attracted considerable attention as a promising strategy for recycling CO2 and generating valuable methane. This study presents a niobium-doped CeO2-supported Ni catalyst (Ni/NbCe), which demonstrates remarkable performance in terms of CO2 conversion and CH4 selectivity, even when operating at a low temperature of 250 °C. Structural analysis reveals the incorporation of Nb species into the CeO2 lattice, resulting in the formation of a Nb-Ce-O solid solution. Compared with the Ni/CeO2 catalyst, this solid solution demonstrates an improved spatial distribution. To comprehend the impact of the Nb-Ce-O solid solution on refining the electronic properties of the Ni-Ce interfacial sites, facilitating H2 activation, and accelerating the hydrogenation of CO2* into HCOO*, in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) analysis and density functional theory (DFT) calculations were conducted. These investigations shed light on the mechanism through which the activity of CO2 methanation is enhanced, which differs from the commonly observed CO* pathway triggered by oxygen vacancies (OV). Consequently, this study provides a comprehensive understanding of the intricate interplay between the electronic properties of the catalyst's active sites and the reaction pathway in CO2 methanation over Ni-based catalysts.
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Photocatalytic overall splitting of pure water (H2O) without sacrificial reagent to hydrogen (H2) and oxygen (O2) holds a great potential for achieving carbon neutrality. Herein, by anchoring cobalt sulfide (Co9S8) as cocatalyst and cadmium sulfide (CdS) as light absorber to channel wall of a porous polymer microreactor (PP12), continuous violent H2 and O2 bubbling productions from photocatalytic overall splitting of pure H2O without sacrificial reagent is achieved, with H2 and O2 production rates as high as 4.41 and 2.20 mmol h-1 gcat.-1 respectively. These are significantly enhanced than those in the widely used stirred tank-type reactor in which no O2 is produced and H2 production rate is only 0.004 mmol h-1 gcat.-1. Besides improved charge separation and interaction of H2O with photocatalyst in PP12, bonding interaction of Co9S8 with PP12 creates abundant catalytic active sites for simultaneous productions of H2 and O2, thus leading to the significantly enhanced H2 and O2 bubbling productions in PP12. This offers a new strategy to enhance photocatalytic overall splitting of pure H2O without sacrificial reagent.
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Solar-energy-driven photoreduction of CO2 is promising in alleviating environment burden, but suffers from low efficiency and over-reliance on sacrificial agents. Herein, rhenium (Re) is atomically dispersed in In2O3 to fabricate a 2Re-In2O3 photocatalyst. In sacrificial-agent-free photoreduction of CO2 with H2O, 2Re-In2O3 shows a long-term stable efficiency which is enhanced by 3.5 times than that of pure In2O3 and is also higher than those on Au-In2O3, Ag-In2O3, Cu-In2O3, Ir-In2O3, Ru-In2O3, Rh-In2O3 and Pt-In2O3 photocatalysts. Moreover, carbon-based product of the photoreduction overturns from CO on pure In2O3 to CH3OH on 2Re-In2O3. Re promotes charge separation, H2O dissociation and CO2 activation, thus enhancing photoreduction efficiency of CO2 on 2Re-In2O3. During the photoreduction, CO is a key intermediate. CO prefers to desorption rather than hydrogenation on pure In2O3, as CO binds to pure In2O3 very weakly. Re strengthens the interaction of CO with 2Re-In2O3 by 5.0 times, thus limiting CO desorption but enhancing CO hydrogenation to CH3OH. This could be the origin for photoreduction product overturn from CO on pure In2O3 to CH3OH on 2Re-In2O3. The present work opens a new way to boost sacrificial-agent-free photoreduction of CO2.
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By supporting platinum (Pt) and cadmium sulfide (CdS) nanoparticles on indium oxide (In2 O3 ), we fabricated a CdS/Pt/In2 O3 photocatalyst. Selective photoreduction of carbon dioxide (CO2 ) to methane (CH4 ) was achieved on CdS/Pt/In2 O3 with electronic Pt-In2 O3 interactions, with CH4 selectivity reaching to 100 %, which is higher than that on CdS/Pt/In2 O3 without electronic Pt-In2 O3 interactions (71.7 %). Moreover, the enhancement effect of electronic Pt-(metal-oxide) interactions on selective photoreduction of CO2 to CH4 also occurs by using other common metal oxides, such as photocatalyst supports, including titanium oxide, gallium oxide, zinc oxide, and tungsten oxide. The electronic Pt-(metal-oxide) interactions separate photogenerated electron-hole pairs and convert CO2 into CO2 δ- , which can be easily hydrogenated into CH4 via a CO2 δ- âHCOO*âHCO*âCH*âCH4 path, thus boosting selective photoreduction of CO2 to CH4 . This offers a new way to achieve selective photoreduction of CO2 .
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Photocatalytic hydrogen (H2 ) production is significant to overcome challenges like fossil fuel depletion and carbon dioxide emission, but its efficiency is still far below that which is needed for commercialization. Herein, we achieve long-term stable H2 bubbling production from water (H2 O) and lactic acid via visible-light-driven photocatalysis in a porous microreactor (PP12); the catalytic system benefits from photocatalyst dispersion, charge separation, mass transfer, and dissociation of O-H bonds associated with H2 O. With the widely used platinum/cadmium-sulfide (Pt/CdS) photocatalyst, PP12 leads to a H2 bubbling production rate of 602.5â mmol h-1 m-2 , which is 1000â times higher than that in a traditional reactor. Even when amplifying PP12 into a flat-plate reactor with an area as large as 1â m2 and extending the reaction time to 100â h, the H2 bubbling production rate still remains at around 600.0â mmol h-1 m-2 , offering great potential for commercialization.
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The absorption coefficient of fused silica for a mid-infrared (IR) laser is higher than that for a near-IR laser, but smaller than that for a far-IR laser. Therefore, the energy coupling efficiency of the mid-IR laser is higher than that for the near-IR laser, while the penetration depth is higher than that for the far-IR laser. Thus, the mid-IR laser is highly efficient in mitigating damage growth. In this study, a deuterium fluoride (DF) laser with a center wavelength of 3.8 µm was used to interact with fused silica. The temperature variation, changes in the reflected and transmitted intensities of the probe light incident on the laser irradiation area, and the vaporization and melting sputtering process were analyzed. The results demonstrate that when the laser intensity was low (<1.2 kW/cm2), no significant melting was observed, and the reflection and transmission properties gradually recovered after the end of the laser irradiation process. With a further increase in the laser intensity, the sample gradually melted and vaporized. At a laser intensity above 5.1 kW/cm2, the temperature of the sample increased rapidly and vapors in huge quantity evaporated from the surface of the sample. Moreover, when the laser intensity was increased to 9.5 kW/cm2, the sample melted and an intense melting sputtering process was observed, and the sample was melted through.
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Lead ion (Pb2+) is one of the most common water pollutants. Herein, with bamboo as the raw material, we fabricate a thin-walled hollow ellipsoidal carbon-based adsorbent (CPCs900) containing abundant O-containing groups and carbon defects and having a specific surface area as large as 730.87 m2 g-1. CPCs900 shows a capacity of 37.26 mg g-1 for adsorbing Pb2+ in water and an efficiency of 98.13% for removing Pb2+ from water. This is much better than the activated carbon commonly used for removing Pb2+ from water (12.19 mg g-1, 30.48%). The bond interaction of Pb2+ with the O-containing groups on CPCs900 and the electrostatic interaction of Pb2+ with the electron-rich carbon defects on CPCs900 could be the main forces to drive Pb2+ adsorption on CPCs900. The outstanding adsorption performance of CPCs900 could be due to the abundant O-containing groups and carbon defects as well as the large specific surface area of CPCs900. Bamboo has a large reserve and a low price. The present work successfully converts bamboo into adsorbents with outstanding performances in removing Pb2+ from water. This is of great significance for meeting the huge industrial demand on highly efficient adsorbents for removing toxic metal ions from water.
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Contaminantes Químicos del Agua , Contaminantes del Agua , Adsorción , Carbón Orgánico/química , Concentración de Iones de Hidrógeno , Iones , Cinética , Plomo , Agua , Contaminantes Químicos del Agua/análisisRESUMEN
COMSOL Multiphysics was employed to establish a dislocation model based on the Alexander and Haasen (AH) model, the heat conduction equation, and Hooke's law for calculating the dislocation distribution of germanium (Ge) under laser irradiation. The numerical simulation results were obtained. A continuous 1080 nm laser was utilized to ablate the monocrystalline Ge wafers to validate the model. The experimental results show that no surface damage appears until the irradiances go up to 234W/cm2 for 100 ms laser ablation. This is consistent with the numerical findings. The initiation times of surface damage by the experiments at 234W/cm2 and above agree well with the numerical results, which means that the model can efficiently predict the dislocation field.
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Three-dimensional and time-dependent thermal lens distribution was measured in K9 glass by a Mach-Zehnder interferometer in this paper. The thermal lens was introduced by focusing a millisecond pulse laser into the glass, and the phase information was extracted by Fourier analysis. The specific internal three-dimensional refractive index variation (RIV) was then deduced from phase maps by an inverse Abel algorithm. It is demonstrated that the stress-induced birefringence would lead to negative RIV, which is contrary to results of temperature increment. The method proposed herein would provide a novel idea for measurement of thermal lenses.
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A selective CO evolution from photoreduction of CO2 in water was achieved on a noble-metal-free, carbide-based composite catalyst, as demonstrated by a CO selectivity of 98.3% among all carbon-containing products and a CO evolution rate of 29.2 µmol h-1, showing superiority to noble-metal-based catalyst. A rapid separation of the photogenerated electron-hole pairs and improved CO2 adsorption on the surface of the carbide component are responsible for the excellent performance of the catalyst. The high CO selectivity is accompanied by a predominant H2 evolution, which is believed to provide a proton-deficient environment around the catalyst to favor the formation of hydrogen-deficient carbon products. The present work provides general insights into the design of a catalyst with a high product selectivity and also the carbon evolution chemistry during a photocatalytic reaction.
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Indium-oxide (In2O3) nanobelts coated by a 5-nm-thick carbon layer provide an enhanced photocatalytic reduction of CO2 to CO and CH4, yielding CO and CH4 evolution rates of 126.6 and 27.9 µmol h-1, respectively, with water as reductant and Pt as co-catalyst. The carbon coat promotes the absorption of visible light, improves the separation of photoinduced electron-hole pairs, increases the chemisorption of CO2, makes more protons from water splitting participate in CO2 reduction, and thereby facilitates the photocatalytic reduction of CO2 to CO and CH4.
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The surface damage morphologies of single-crystal silicon induced by a combined pulse laser (CPL) and a single millisecond laser are investigated, respectively. The CPL includes a millisecond (ms) laser superposed by a nanosecond (ns) laser. Inspected by an optical microscope, it was found that the surface damage was more serious when the sample was irradiated by the CPL than by a single ms laser with the same incident laser energy. Besides surface cleavage, obvious ablation and fold areas were discovered by CPL irradiation. A two-dimensional spatial axisymmetric model was established to assess the difference between single ms laser and CPL irradiation and explain the generation mechanism of the different surface damage. This was attributed to the preheating effect by the ms laser and the surface damage caused by the ns laser.
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Optical beam deflection and high-speed photographic methods are employed to investigate the interaction mechanism between a laser-induced bubble and a metal target for underwater laser propulsion. A preliminary theory is proposed to reveal the step increases of the kinetic energy transferred to the target during the process of increasing the incident laser energy. This theory also helps to explain the increasing coupling efficiency with incident laser energy for underwater laser propulsion.
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A millisecond laser combined with a nanosecond laser was applied to machining transparent materials. The influences of delay between the two laser pulses on processing efficiencies and modified sizes were studied. In addition, a laser-supported combustion wave (LSCW) was captured during laser irradiation. An optimal delay corresponding to the highest processing efficiency was found for cone-shaped cavities. The modified size as well as the lifetime and intensity of the LSCW increased with the delay decreasing. Thermal cooperation effects of defects, overlapping effects of small modified sites, and thermal radiation from LSCW result in all the phenomena.
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A new form of double pulse composed of a nanosecond laser and a millisecond laser is proposed for laser machining transparent materials. To evaluate its advantages and disadvantages, experimental investigations are carried out and the corresponding results are compared with those of single millisecond laser. The mechanism is discussed from two aspects: material defects and effects of modifications induced by nanosecond laser on thermal stress field during millisecond laser irradiation. It is shown that the modifications of the sample generated by nanosecond laser improves the processing efficiency of subsequent millisecond laser, while limits the eventual size of modified region.
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Fabrication of organic thin films with highly dispersed inorganic nanoparticles is a very challenging topic. In this work, a new approach that combines electron-induced molecular self-assembly with simultaneous nanoparticle formation by room temperature electron reduction was developed to prepare peptide thin films with highly dispersed noble metal nanoparticles. Argon glow discharge was employed as the resource of electrons. The peptide motif KLVFF (Aß16-20) self-assembled into two-dimensional membranes under the influence of hydrated electrons, while the metal ions in solution can be simultaneously reduced by electrons to form nanoparticles. Our TEM imaging reveals that metal nanoparticles were well-distributed in the resulting peptide thin films. Our results also suggest that the size of metal nanoparticles can be tuned by varying the initial concentration of the metal ion. This simple approach can be viewed as a promising strategy to create hybrid thin films that integrate functional inorganics into biomolecule scaffolds.
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Nanopartículas del Metal/química , Péptidos/química , Argón/química , Oro/química , Microscopía de Fuerza Atómica , Propiedades de SuperficieRESUMEN
Objective: To evaluate the diagnostic performance and inter-observer agreement of the American College of Radiology Ovarian-Adnexal Reporting and Data System Ultrasound (O-RADS) in the diagnosis of ovarian masses in children. Methods: From June 2012 to December 2021, 163 ovarian masses in 159 patients with pathologic results were retrospectively analyzed. Each mass was classified into an O-RADS category according to the criteria. The diagnostic performance of O-RADS for detecting malignant ovarian masses was assessed using histopathology as the reference standard. Kappa (k) statistic was used to assess inter-observer agreement between a less-experienced and a well-experienced radiologist. Results: Out of 163 ovarian masses, 18 (11.0%) were malignant and 145 (89.0%) were benign. The malignancy rates of O-RADS 5, O-RADS 4, and O-RADS 3 masses were 72.7%, 34.6%, and 4.8%, respectively. The area under the receiver operating characteristic curve was 0.944 (95% CI, 0.908-0.981). The optimal cutoff value for predicting malignant ovarian masses was > O-RADS 3 with a sensitivity, specificity, and accuracy of 94.4%, 86.2% and 86.2% respectively. The inter-observer agreement of the O-RADS category was good (k = 0.777). Conclusions: O-RADS has a high diagnostic performance for children with ovarian masses. It provides an effective malignant risk classification for ovarian masses in children, which shows high consistency between radiologists with different levels of experience.
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Peptide assembly: a 2D peptide (Aß16-22) film was produced successfully by introducing hydrated electrons into the assembly process of Aß16-22. The interplay between experiment and theoretical calculation indicates that the film formation can be enhanced through the interactions between hydrated electrons and Aß16-22.
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Péptidos beta-Amiloides/química , Amiloide/química , Fragmentos de Péptidos/química , Péptidos/química , Simulación por Computador , Electrones , Estructura Secundaria de ProteínaRESUMEN
Photocatalytic hydrogen peroxide (H2O2) production will become a burgeoning strategy for solar energy utilization by selective oxygen reduction reaction (ORR). Polymeric carbon nitride (PCN) shows relatively high two-electron ORR selectivity for H2O2 production but still limited low H2O2 production efficiency due to slow exciton dissociation. Herein, we constructed a heptazine/triazine layer stacked carbon nitride heterojunction with fluorine/potassium (F/K) dual sites (FKHTCN). The introduction of F/K not only can regulate layer components to enhance the charge separation efficiency but, more importantly, also optimize the adsorption of surface oxygen molecules and intermediate *OOH during H2O2 production. Consequently, FKHTCN efficiently improves the photocatalytic H2O2 production rate up to 3380.9 µmol h-1 g-1, nearly 15 times higher than that of traditional PCN. Moreover, a production-utilization cascade system was designed to explore their practical application in environmental remediation. This work lays out the importance of engineering a layer-stacked configuration and active sites for enhancing photocatalysis.