Diagnostic and prognostic performance of artificial intelligence-based fully-automated on-site CT-FFR in patients with CAD.

Currently, clinically available coronary CT angiography (CCTA) derived fractional flow reserve (CT-FFR) is time-consuming and complex. We propose a novel artificial intelligence-based fully-automated, on-site CT-FFR technology, which combines the automated coronary plaque segmentation and luminal extraction model with reduced order 3 dimentional (3D) computational fluid dynamics. A total of 463 consecutive patients with 600 vessels from the updated China CT-FFR study in Cohort 1 undergoing both CCTA and invasive fractional flow reserve (FFR) within 90 d were collected for diagnostic performance evaluation. For Cohort 2, a total of 901 chronic coronary syndromes patients with index CT-FFR and clinical outcomes at 3-year follow-up were retrospectively analyzed. In Cohort 3, the association between index CT-FFR from triple-rule-out CTA and major adverse cardiac events in patients with acute chest pain from the emergency department was further evaluated. The diagnostic accuracy of this CT-FFR in Cohort 1 was 0.82 with an area under the curve of 0.82 on a per-patient level. Compared with the manually dependent CT-FFR techniques, the operation time of this technique was substantially shortened by 3 times and the number of clicks from about 60 to 1. This CT-FFR technique has a highly successful (> 99%) calculation rate and also provides superior prediction value for major adverse cardiac events than CCTA alone both in patients with chronic coronary syndromes and acute chest pain. Thus, the novel artificial intelligence-based fully automated, on-site CT-FFR technique can function as an objective and convenient tool for coronary stenosis functional evaluation in the real-world clinical setting.

Edge-Type Hyperintense Intracranial Artery Plaque: A Potential MRI Biomarker of Stroke Recurrence.

BACKGROUND: Identifying patients at high risk of stroke recurrence is important for stroke prevention and treatment. PURPOSE: To explore the characteristics of T1 hyperintense plaques (HIP) and their relationship with stroke recurrence in patients with symptomatic intracranial atherosclerotic stenosis (sICAS). STUDY TYPE: Retrospective. POPULATION: One hundred fifty-seven patients with moderate-to-severe (≥50%) nonocclusive sICAS and MRI studies (42 females and 115 males, mean age 58.69 ± 10.68 years). FIELD STRENGTH/SEQUENCE: 3D higher-resolution black-blood T1-weighted fast-spin-echo sequence at 3.0 T. ASSESSMENT: HIP (signal intensity [SI] of plaque-to-adjacent gray matter >1.0 on non-contrast T1-weighted images) and non-HIP plaques were identified. HIP plaques were categorized as edge type (high SI adjacent to lumen) and non-edge type (high SI within plaque). Clinical and imaging features of different plaque types were compared. Stroke recurrence was assessed through telephone or medical records at 3 and 6 months, and then once a year post-MRI. The relationship between edge type and non-edge types HIP with stroke recurrence was analyzed. STATISTICAL TESTS: Student's t test, Mann-Whitney U-test, chi square test and Fisher's exact test to compare features between plaque types. Kaplan-Meier curves (with log-rank tests) and Cox proportional hazards regression to assess relationship between stroke recurrence and different plaque types. A two-tailed P-value of <0.05 was considered statistically significant. RESULTS: Of 157 culprit lesions, 87 (55%) were HIPs (43 edge type, 44 non-edge type) and 70 (45%) were non-HIPs. Plaque thickness, area, and volume were significantly higher for HIPs than for non-HIPs. Among patients with HIPs, edge type was significantly more likely in the posterior circulation (53.5% vs. 27.3%), and had significantly higher plaque thickness, length, area, volume, plaque burden, and remodeling index than non-edge type. Edge-type HIP was significantly more common than non-edge HIP in patients with diabetes mellitus (51.2% vs. 29.5%) and dyslipidemia (79.1% vs. 54.5%). During median follow-up of 27 months, 33 patients experienced stroke recurrence. Recurrence was associated with edge-type HIP (adjusted hazard ratio = 2.83; 95% confidence interval: 1.40-5.69), both in the overall cohort (34.9% vs. 15.8%) and in patients with HIP (34.9% vs. 9.0%). Age ≥60 years and edge-type HIP had a significant interaction. DATA CONCLUSIONS: Hyperintense plaque may be categorized as edge type or non-edge type. Edge-type HIP may be a potential MRI biomarker of stroke recurrence. EVIDENCE LEVEL: 3 TECHNICAL EFFICACY: Stage 2.

Coronary Computed Tomography Angiography-derived Fractional Flow Reserve: An Expert Consensus Document of Chinese Society of Radiology.

Invasive fractional flow reserve (FFR) measured by a pressure wire is a reference standard for evaluating functional stenosis in coronary artery disease. Coronary computed tomography angiography-derived fractional flow reserve (CT-FFR) uses advanced computational analysis methods to noninvasively obtain FFR results from a single conventional coronary computed tomography angiography data to evaluate the hemodynamic significance of coronary artery disease. More and more evidence has found good correlation between the results of noninvasive CT-FFR and invasive FFR. CT-FFR has proven its potential in optimizing patient management, improving risk stratification and prognosis, and reducing total health care costs. However, there is still a lack of standardized interpretation of CT-FFR technology in real-world clinical settings. This expert consensus introduces the principle, workflow, and interpretation of CT-FFR; summarizes the state-of-the-art application of CT-FFR; and provides suggestions and recommendations for the application of CT-FFR with the aim of promoting the standardized application of CT-FFR in clinical practice.

Coral-Shaped MoS2 Decorated with Graphene Quantum Dots Performing as a Highly Active Electrocatalyst for Hydrogen Evolution Reaction.

We report a new CVD method to prepare coral-shaped monolayer MoS2 with a large amount of exposed edge sites for catalyzing hydrogen evolution reaction. The electrocatalytic activities of the coral-shaped MoS2 can be further enhanced by electronic band engineering via decorated with graphene quantum dot (GQD) decoration. Generally, GQDs improve the electrical conductivity of the MoS2 electrocatalyst. First-principles calculations suggest that the coral MoS2@GQD is a zero-gap material. The high electric conductivity and pronounced catalytically active sites give the hybrid catalyst outstanding electrocatalytic performance with a small onset overpotential of 95 mV and a low Tafel slope of 40 mV/dec as well as excellent long-term electrocatalytic stability. The present work provides a potential way to design two-dimensional hydrogen evolution reaction (HER) electrocatalysts through controlling the shape and modulating the electric conductivity.

Hollow Structured Micro/Nano MoS2 Spheres for High Electrocatalytic Activity Hydrogen Evolution Reaction.

Molybdenum disulfide (MoS2) has attracted extensive attention as a non-noble metal electrocatalyst for hydrogen evolution reaction (HER). Controlling the skeleton structure at the nanoscale is paramount to increase the number of active sites at the surface. However, hydrothermal synthesis favors the presence of the basal plane, limiting the efficiency of catalytic reaction. In this work, perfect hollow MoS2 microspheres capped by hollow MoS2 nanospheres (hH-MoS2) were obtained for the first time, which creates an opportunity for improving the HER electrocatalytic performance. Benefiting from the controllable hollow skeleton structure and large exposed edge sites, high-efficiency HER activity was obtained for stacked MoS2 thin shells with a mild degree of disorder, proving the presence of rich active sites and the validity of the combined structure. In general, the obtained hollow micro/nano MoS2 nanomaterial exhibits optimized electrocatalytic activity for HER with onset overpotential as low as 112 mV, low Tafel slope of 74 mV decade(-1), high current density of 10 mA cm(-2) at η = 214 mV, and high TOF of 0.11 H2 s(-1) per active site at η = 200 mV.

Preparation of hollow microsphere@onion-like solid nanosphere MoS2 coated by a carbon shell as a stable anode for optimized lithium storage.

A one-step hydrothermal method was successfully used to fabricate hollow microsphere@onion-like solid nanosphere MoS2. Then the as-prepared sS-MoS2 was decorated with a carbon shell using dopamine as a carbon source by a facile route, resulting in hollow microsphere@onion-like solid nanosphere MoS2 decorated with carbon shell (sS-MoS2@C). A synergistic effect was observed for the two-component material, leading to new electrochemical processes for lithium storage, with improved electroconductivity and structural soundness, triggering an ascending capacity upon cycling. The as-prepared sS-MoS2@C exhibits optimized electrochemical behaviour with high specific capacity (1107 mA h g(-1) at 100 mA g(-1)), superior high-rate capability (805 mA h g(-1) at 5000 mA g(-1)) and good cycling stability (91.5% of capacity retained after 100 cycles), suggesting its potential application in high-energy lithium-ion batteries.

Charge-Transfer Induced High Efficient Hydrogen Evolution of MoS2/graphene Cocatalyst.

The MoS2 and reduced graphite oxide (rGO) composite has attracted intensive attention due to its favorable performance as hydrogen evolution reaction (HER) catalyst, but still lacking is the theoretical understanding from a dynamic perspective regarding to the influence of electron transfer, as well as the connection between conductivity and the promoted HER performance. Based on the first-principles calculations, we here clearly reveal how an excess of negative charge density affects the variation of Gibbs free energy (ΔG) and the corresponding HER behavior. It is demonstrated that the electron plays a crucial role in the HER routine. To verify the theoretical analyses, the MoS2 and reduced graphite oxide (rGO) composite with well defined 3-dimensional configuration was synthesized via a facile one-step approach for the first time. The experimental data show that the HER performance have a direct link to the conductivity. These findings pave the way for a further developing of 2-dimension based composites for HER applications.

Multi-slice nanostructured WS2@rGO with enhanced Li-ion battery performance and a comprehensive mechanistic investigation.

A thin nanoslice structured WS2@reduced graphene oxide (rGO) composite was successfully fabricated by a facile hydrothermal synthesis method. The layered structure and morphology of the composite were investigated by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The WS2@rGO composite structure demonstrated significantly enhanced rate capability performance in comparison with pristine WS2 when used as an anode material for lithium-ion batteries (LIBs). The composite demonstrated a capacity of 565 mA h g(-1) after 100 cycles when cycled at 0.1 A g(-1) and it could still deliver a stable capacity of about 337 mA h g(-1) at 2 A g(-1). Electrochemical impedance spectroscopy (EIS) measurement showed that the synergistic effect between WS2 and rGO could remarkably reduce the contact resistance and improve the corresponding electrochemical performances. In order to analyze and interpret the corresponding results from a theoretically sound perspective, first principles calculations was further performed to investigate the corresponding inner mechanisms of pristine WS2 and WS2@graphene composite. The nudged elastic band (NEB) method was used to investigate the diffusion properties of Li in the different structures. Molecular dynamics (MD) simulation and Young's modulus calculation were further employed to explore the stability and mechanical properties of the two structures for the first time. These new perspectives pave the way for the design and fabrication of graphene-TMDs based composites as the next generation of LIB anode materials with high power density and cycling stability.

Synthesis of the MoS2@CuO heterogeneous structure with improved photocatalysis performance and H2O adsorption analysis.

MoS2@CuO heterogeneous structure nanoflowers were synthesized through a two-step hydrothermal method for the first time. The valence band offset (VBO) and conduction band offset (CBO) of the MoS2@CuO heterojunction, and the bases for the design of the heterogeneous structure were determined by X-ray photoemission spectroscopy (XPS). For the increased specific surface area and the formation of staggered type-II band alignment of the composite structure, a significantly enhanced photocatalytic ability of the MoS2@CuO heterojunction was obtained by studying the photodegradation of methylene blue (MB). After irradiation for 100 min, the residual MB in solution was about 27.5% for pristine MoS2 nanoflowers while it was 4.3% for MoS2@CuO hetero-nanoflowers, respectively. The humidity sensing properties of the two nanostructures were also studied for comparison. The results showed that better response/recover times were obtained. In order to give a theoretical explanation for this phenomenon, we performed first-principles calculation to analyse the corresponding humidity sensing mechanisms of MoS2 and MoS2@CuO in detail. The calculated results showed that water molecules could bind stronger to the CuO surface compared to MoS2, which is in line with the experimental observations.

Novel photoluminescence properties and enhanced photocatalytic activities for V2O5-loaded ZnO nanorods.

Three different kinds of V2O5/ZnO heteronanorods were synthesized through a CVD process and oxidized in air at temperatures of 350, 420 and 500 °C. These 1D heteronanorods were formed from ZnO nanorods (NRs) coated with V2O5 nanoparticles (NPs). With the rise of oxidation temperature, the coated V2O5 NPs were found to be growing and their crystallinity gradually improved. Photoluminescence (PL) spectra for these V2O5/ZnO samples exhibited some novel characteristics, such as the appearance of new emission peaks, the variation in PL intensity, and the tremendously enhanced visible emission for the 500 °C sample. Photocatalysis investigation for all V2O5/ZnO samples showed enhanced photocatalytic activities compared to their single-component counterparts. Furthermore, their photocatalytic activities were also influenced by the oxidation temperature. The 350 °C sample showed the highest photocatalytic activity, and gradually decreased photocatalytic activities were observed for the other two samples. The novel PL properties and enhanced photocatalytic activities were attributed to the coupling between ZnO NRs and V2O5 NPs, and can be attributed to the collective effect of the V-doped ZnO layer near the interface, the decreased defect concentration in V2O5 NPs, and the improved particle crystallinity.

Enhanced field emission and photocatalytic performance of MoS2 titania nanoheterojunctions via two synthetic approaches.

Two types of molybdenum disulfide (MoS2) titania nanoheterojunctions with different morphologies were synthesized via two different approaches. They were facile and additive-free hydrothermal processes, which resulted in a high material productivity and controllable morphologies. Both the synthesis and their growth mechanisms are discussed in this paper. The field emission properties of MoS2 titania nanoheterojunctions were investigated in this research. The experimental data indicated that the MoS2@TiO2 heterojunctions had an excellent field emission performance with a turn-on field of 2.2 V µm(-1) and threshold field of 3.6 V µm(-1) on Si substrate because of the large quantities of sharp edges. Furthermore, because the p-n heterojunctions were formed, the photocatalytic activities of both composites were evaluated by monitoring the photodegradation of methylene blue. The results showed that the TiO2@MoS2 heterojunctions had better photocatalytic properties with 90% degradation within 100 minutes. The morphological differences generated from different synthetic approaches made a huge impact on the composites' properties.