Simultaneously increasing the activity and stability of the single-atom active sites of M-N-C catalysts is critical but remains a great challenge. Here, we report an Fe-N-C catalyst with ...nitrogen-coordinated iron clusters and closely surrounding Fe-N
active sites for oxygen reduction reaction in acidic fuel cells. A strong electronic interaction is built between iron clusters and satellite Fe-N
due to unblocked electron transfer pathways and very short interacting distances. The iron clusters optimize the adsorption strength of oxygen reduction intermediates on Fe-N
and also shorten the bond amplitude of Fe-N
with incoherent vibrations. As a result, both the activity and stability of Fe-N
sites are increased by about 60% in terms of turnover frequency and demetalation resistance. This work shows the great potential of strong electronic interactions between multiphase metal species for improvements of single-atom catalysts.
In the past decade, the introduction of molecularly targeted agents and immune-checkpoint inhibitors has led to improved survival outcomes for patients with advanced-stage lung cancer; however, this ...disease remains the leading cause of cancer-related mortality worldwide. Two large randomized controlled trials of low-dose CT (LDCT)-based lung cancer screening in high-risk populations - the US National Lung Screening Trial (NLST) and NELSON - have provided evidence of a statistically significant mortality reduction in patients. LDCT-based screening programmes for individuals at a high risk of lung cancer have already been implemented in the USA. Furthermore, implementation programmes are currently underway in the UK following the success of the UK Lung Cancer Screening (UKLS) trial, which included the Liverpool Health Lung Project, Manchester Lung Health Check, the Lung Screen Uptake Trial, the West London Lung Cancer Screening pilot and the Yorkshire Lung Screening trial. In this Review, we focus on the current evidence on LDCT-based lung cancer screening and discuss the clinical developments in high-risk populations worldwide; additionally, we address aspects such as cost-effectiveness. We present a framework to define the scope of future implementation research on lung cancer screening programmes referred to as Screening Planning and Implementation RAtionale for Lung cancer (SPIRAL).
Ellipsometric scatterometry has gained wide industrial applications in semiconductor manufacturing after ten years of development. Among the various types of ellipsometers, Mueller matrix ...ellipsometer (MME) can provide all 16 elements of the 4 by 4 Mueller matrix, and consequently, MME-based scatterometry can acquire much more useful information about the sample and thereby can achieve better measurement sensitivity and accuracy. In this paper, the basic principles and instrumentation of MME are presented, and the data analysis in MME-based nanostructure metrology is revisited from the viewpoint of computational metrology. It is pointed out that MME-based nanometrology is essentially a computational metrology technique by modeling a complicated forward process followed by solving a nonlinear inverse problem. Several case studies are finally provided to demonstrate the potential of MME in nanostructure metrology.
•Principles of Mueller matrix ellipsometry (MME) based scatterometry are presented.•We developed a broadband dual rotating-compensator Mueller matrix ellipsometer.•The data analysis is revisited from the viewpoint of computational metrology.•Potential of MME in nanostructure metrology is demonstrated using case studies.
Van der Waals heterostructures (vdWHs) based on 2D layered materials with selectable materials properties pave the way to integration at the atomic scale, which may give rise to fresh ...heterostructures exhibiting absolutely novel physics and versatility. This feature article reviews the state‐of‐the‐art research activities that focus on the 2D vdWHs and their optoelectronic applications. First, the preparation methods such as mechanical transfer and chemical vapor deposition growth are comprehensively outlined. Then, unique energy band alignments generated in 2D vdWHs are introduced. Furthermore, this feature article focuses on the applications in light‐emitting diodes, photodetectors, and optical modulators based on 2D vdWHs with novel constructions and mechanisms. The recently reported novel constructions of the devices are introduced in three primary aspects: light‐emitting diodes (such as single defect light‐emitting diodes, circularly polarized light emission arising from valley polarization), photodetectors (such as photo‐thermionic, tunneling, electrolyte‐gated, and broadband photodetectors), and optical modulators (such as graphene integrated with silicon technology and graphene/hexagonal boron nitride (hBN) heterostructure), which show promising applications in the next‐generation optoelectronics. Finally, the article provides some conclusions and an outlook on the future development in the field.
van der Waals heterostructures (VdWHs) have experienced a booming development in recent years. In this feature article, preparation methods, electronic and optical properties, and applications in optoelectronics of vdWHs are presented.
In this work, a cleaner and effective method for selective extraction of iron from vanadium slag was developed, including carbothermal reduction of iron from vanadium slag, chlorination of reduced ...slag, and electrolysis of chlorinated slag. In the reduction process of vanadium slag, the influence of temperature and C/slag mass ratio on the reduction percentage of FeO, V2O3, Cr2O3, MnO and TiO2 were also investigated by isothermal method. Under the optimal process conditions, the reduction percentage of FeO, V2O3, Cr2O3, MnO, and TiO2 in vanadium slag is 38.6% at 1100 °C for 135 min and the metallization ratio of Fe is 85.4%. After carbothermal reduction of vanadium slag, the unreduced iron oxide is chlorinated to obtain FeCl2 and the chlorination rate of unreduced iron oxide is 85.6% at 900 °C for 4 h. In the electrolysis process, the selective electrolysis of iron ions is achieved by controlling the potential of electrolysis to obtain metal Fe (95 wt%) with 0.9 wt% of V and 0.25 wt% of Cr at 1.6 V. This is a new and cleaner method for the selective removal of Fe from vanadium slag. This novel and cleaner process has potential application for processing materials with high Fe content and low content of other valuable elements (Ti, Cr, V, Nb, etc) such as rare earth iron ore, vanadium titanomagnetite ore, and chromite ore.
•A new process to selectively extract Fe from vanadium slag was proposed.•The reduction percentage of oxides in vanadium slag was 38.6% at 1100 °C for 135 min.•The chlorination rate of iron oxide in reduced slag is 85.6% at 900 °C for 4 h.•Metallic iron with 95 wt% Fe, 0.9 wt% V and 0.25 wt% Cr was obtained by electrolysis.
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•Broadband optical properties of graphene and HOPG are comparatively studied by MME.•Optical and dielectric models are constructed for the ellipsometric analysis.•Some intrinsic ...features of graphene and HOPG are observed and discussed.•Physical mechanisms of these intrinsic features are revealed and compared.
Optical properties of mono-graphene fabricated by chemical vapor deposition (CVD) and highly oriented pyrolytic graphite (HOPG) are comparatively studied by Mueller matrix ellipsometry (MME) over an ultra-wide energy range of 0.73–6.42 eV. A multilayer stacking model is constructed to describe the CVD mono-graphene, in which the roughness of the glass substrate and the water adsorption on the graphene are considered. We introduce a uniaxial anisotropic dielectric model to parameterize the optical constants of both the graphene and the HOPG. With the established models, broadband optical constants of the graphene and the HOPG are determined from the Mueller matrix spectra based on a point-by-point method and a non-linear regression method, respectively. Two significant absorption peaks at 4.75 eV and 6.31 eV are observed in the extinction coefficient spectra of the mono-graphene, which can be attributed to the von-Hove singularity (i.e., the π-to-π∗ exciton transition) near the M point and the σ-to-σ∗ exciton transition near the Γ point of the Brillouin zone, respectively. Comparatively, only a major absorption peak at 4.96 eV appears in the ordinary extinction coefficient spectra of the HOPG, which is mainly formed by the π-to-π∗ interband transition.
Image-guided combined chemo-thermal therapy assists in optimizing treatment time, enhancing therapeutic efficiency, and circumventing side effects. In the present study, we developed a ...chemo-photothermal theranostic platform based on polydopamine (PDA)-coated gold nanorods (GNRs). The PDA coating was thin; however, it significantly suppressed the cytotoxicity of the cetyltrimethylammonium bromide template and allowed high cisplatin loading efficiency, arginine-glycine-aspartic acid (RGD) peptide (c(RGDyC)) conjugation, and chelator-free iodine-125 labeling (RGD-125IPt-PDA@GNRs). While loaded cisplatin was released in a pH-sensitive manner, labeled 125I was outstandingly stable under biological conditions. RGD-125IPt-PDA@GNRs had a high specificity for αvβ3 integrin, and consequently, they could selectively accumulate in tumors, as revealed by single photon emission computed tomography/CT imaging, and in target tumor angiogenic vessels, as shown by high-resolution photoacoustic imaging. As RGD-125IPt-PDA@GNRs targets tumor angiogenesis, it is a highly potent tumor therapy. Combined chemo-photothermal therapy with probes could thoroughly ablate tumors and inhibit tumor relapse via a synergistic antitumor effect. Our studies demonstrated that RGD-125IPt-PDA@GNRs is a robust platform for image-guided, chemo-thermal tumor therapy with outstanding synergistic tumor killing and relapse inhibition effects.
Disposal of slags from alloy steelmaking is a serious problem as the toxic metals in the slag such as chromium and vanadium can be leached out. Recovery of the valuable metals needs an effective, ...economically viable method with a minimum number of unit processes. In the present work, a novel process for simultaneous recovery of iron, vanadium, titanium, chromium, and manganese from vanadium slag is proposed including the chlorination of vanadium slag in molten salt and electrolysis of the salt bath. The optimal conditions for the chlorination are an AlCl3–slag mass ratio of 1.5:1 and a salt bath composition (NaCl–KCl)–AlCl3 mass ratio of 1.66:1, at 900 °C for 8 h. The chlorination ratio of iron, vanadium, chromium, and manganese can reach 90.3%, 76.5%, 81.9%, and 97.3%, respectively, and the titanium volatilization ratio was 79.9%. Metal chlorides in molten salts are electrolyzed at 900 °C with graphite electrodes. Valuable metals (Fe, V, Cr, Mn) were deposited on the cathode in terms of alloy or metal of granular shape. The possible mechanisms involved in these findings were explored. The main compositions of residue are Al2O3 and SiO2, which has the potential usage for landfilling and or building by mixing with other substances for instance.
A new n‐type polymer, PF3N‐2TNDI, with high electron mobility, is developed as efficient cathode interfacial material and interconnecting layer (ICL) for constructing high‐performance tandem organic ...solar cells. Tandem cells employing the ICL with structure of PF3N‐2TNDI/Ag/PEDOT:PSS achieve a high power conversion efficiency (PCE) of 11.35%. Moreover, flexible tandem cells with PCE over 10% are also demonstrated.
Objectives
To identify the radiomics signature allowing preoperative discrimination of lung invasive adenocarcinomas from non-invasive lesions manifesting as ground-glass nodules.
Methods
This ...retrospective primary cohort study included 160 pathologically confirmed lung adenocarcinomas. Radiomics features were extracted from preoperative non-contrast CT images to build a radiomics signature. The predictive performance and calibration of the radiomics signature were evaluated using intra-cross (n=76), external non-contrast-enhanced CT (n=75) and contrast-enhanced CT (n=84) validation cohorts. The performance of radiomics signature and CT morphological and quantitative indices were compared.
Results
355 three-dimensional radiomics features were extracted, and two features were identified as the best discriminators to build a radiomics signature. The radiomics signature showed a good ability to discriminate between invasive adenocarcinomas and non-invasive lesions with an accuracy of 86.3%, 90.8%, 84.0% and 88.1%, respectively, in the primary and validation cohorts. It remained an independent predictor after adjusting for traditional preoperative factors (odds ratio 1.87,
p
< 0.001) and demonstrated good calibration in all cohorts. It was a better independent predictor than CT morphology or mean CT value.
Conclusions
The radiomics signature showed good predictive performance in discriminating between invasive adenocarcinomas and non-invasive lesions. Being a non-invasive biomarker, it could assist in determining therapeutic strategies for lung adenocarcinoma.
Key Points
• The radiomics signature was a non-invasive biomarker of lung invasive adenocarcinoma.
• The radiomics signature outweighed CT morphological and quantitative indices.
• A three-centre study showed that radiomics signature had good predictive performance.
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