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The hyperspectral image (HSI) super-resolution reconstruction has attracted much attention and been used widely in various study fields due to its low requirements on hardware in practice. However, most of the hyperspectral image super-resolution reconstruction studies apply one strategy for images with varying complexity of spatial information. This is not conducive to the improvement of Image processing efficiency and the extraction of complex details. Given the above, a new method named MSDESR (multilevel streams and detail enhancement) is proposed to reconstruct HSI by using partition reconstruction and detail enhancement. The MSDESR consists of a sub-map shunt block, a high-low-frequency information extraction with detail enhancement block, and a partition image reconstruction block. Firstly, the sub-map shunt block is designed to pre-classify hyperspectral images. The images are divided into complex and simple parts according to the spatial information distribution of the reconstructed sub-map. Secondly, the multiscale Retinex with detail enhancement algorithm is constructed to purify high-frequency noise-contaminated and enhance the image details by separating the samples into high- and low-frequency information. Finally, branching networks of different complexities are designed to reconstruct the images with high credibility and clear content. In this paper, datasets of QUST-1, Pavia University, Chikusei, the Washington DC Mal and XiongAn are applied in the experiments. The results show that MSDESR outperforms state-of-the-art CNN-based methods in terms of quantitative metrics, visual quality, and computational effort, with a 4.18% and 9.35% improvement in SRE and MPSNR metrics, and a 37% saving in FLOPs. Overall, the MSDESR performs well in hyperspectral image super-resolution reconstruction, which is time saving and preserves the details of spatial information. [ABSTRACT FROM AUTHOR]

Computation-intensive applications offloading is challenging, especially in the designated regions where communication infrastructure is absent or compromised. In this paper, we present a Space–Air–Ground integrated Mobile Edge Computing (SAGiMEC) system for these regions to provide quality computational services, where the unmanned aerial vehicles (UAVs) act as in-fight edge servers to provide low-latency edge computing and the satellite provides resident cloud computing. A joint optimization problem is formulated considering UAV deployment, ground device (GD) access, and computation offloading to minimize the system average response latency. To cope with the problem's complexity, we propose a Particle Swarm Optimization (PSO) and Greedy Strategy (GS)-based algorithm (PSO&GS) to obtain an approximate optimal solution. Extensive simulations validate the convergence of the proposed algorithm. Numerical results show that the proposed approach has excellent convergence, and the system average response latency is about 0.65x–0.85x that of the benchmark algorithm. [ABSTRACT FROM AUTHOR]

In this work, the effects of the solvents, pH, and concentration on the photolysis of CH3I under UV irradiation were investigated. The photolysis of CH3I mainly occurs in the gas phase and is faster in its aqueous solution compared to in its n-hexane and methanol–water solutions. UV irradiation-induced photolysis of CH3I produces I2 and I3− whereas the formation of the latter is affected by the former. In addition, both the pH and concentration of CH3I aqueous solutions affect the formation and transformation of I3− and I2. The results are helpful and referable to understanding the photolysis behavior of CH3I under UV irradiation. [ABSTRACT FROM AUTHOR]

Recently, hyperspectral image (HSI) super-resolution (SR) techniques based on deep learning have been actively developed. However, most hyperspectral image super-resolution reconstruction methods usually use all spectral bands simultaneously, leading to a mismatch of spectral properties between reconstructed HSI bands. Therefore, we proposed a new method of spatial-spectral dual path residual network (SGDPRN) based on spectral response function (SRF) to address the above problem. The SGDPRN is composed of the SRF guided grouping part, the spatial-spectral feature extraction part, and the final reconstruction part. Firstly, the reconstructed features for different spectral ranges are identified separately using SRF as a guide. Then, based on the grouping results, a spatial-spectral dual-path residual block is used to explore the spatial and spectral features by the designed parallel structure simultaneously. The spatial path is designed to extract sharp edges and realistic textures, and the spectral path is designed to model inter-spectral correlations to refine spectral features. At last, the third block of SGDPRN concatenates features of all groups and finishes the reconstruction of HSISR. QUST-1 satellite images have been applied in experiments, and the results showed that SGDPRN produced a higher peak signal to noise ratio, structural similarity metric, correlation coefficient, and lower spectral angle mapper, root mean square error than the other methods. This demonstrates that our method can effectively maintain the correlation of spectral bands while improving the spatial resolution. [ABSTRACT FROM AUTHOR]

To overcome the drawbacks of the single N-doped carbon materials, the further development of dual-heteroatoms (N and S) co-doped electrocatalysts is highly anticipated. Herein, N, S-doping and Fe-based carbon materials were synthesized by pyrolyzing a metal–organic framework (MIL-88) with the addition of N-/N, and S-containing ligands (chitosan and L-Cysteine) in the case of iron salt. The resulting electrocatalyst heat-treated at 850 °C (FeNSC-850) displays superior oxygen reduction reaction (ORR) performances to MIL-88-850, with an overall electron transfer number of 3.97 and a minor yield of HO2- (<2.6%). In addition to the comparable activity to commercial Pt/C in catalyzing the ORR in alkaline solution, the FeNSC-850 also shows higher stability, with a slight decline in half-wave potential (∆E1/2 = 15 mV) after 5000-cycle scanning of cyclic voltammetry. In view of the multiple Fe-based active sites, the additional S doping within FeNSC-850 creates more FeSx active sites for boosting the ORR performances in alkaline solution. [ABSTRACT FROM AUTHOR]

Surface enhanced Raman scattering (SERS) is a highly sensitive spectral analysis technique for ultra‐low trace molecule detection. Conventionally, noble metals like silver (Ag) and gold (Au) are used to prepare the SERS substrates; however, it usually requires careful experiment design and accurate process control, which defers their wide applications in practice. In this paper, a one‐step and low‐cost approach to prepare silver decorated porous carbon (Ag NPs/PCN) films for SERS application is reported. Experimentally, gelatin‐silver nitrate mixed solution was first spin‐coated on the Si substrates to form the thin films, and then, the substrates were carbonized at the different temperatures to obtain the Ag NPs/PCN films. The SERS performance of the Ag NPs/PCN films was evaluated by using the R6G as Raman reporter. Results reveal that the SERS activity is closely related to the spin‐coating rate and carbonization temperature. And detection limit of 10−8 M with the Raman enhancement factor of 1.64 × 106 (10−4‐M R6G) can be obtained on the most optimal substrate. Moreover, large‐scale mapping measurement further evidences that excellent Raman signal uniformity with the RSD of 6.93% also can be achieved. [ABSTRACT FROM AUTHOR]

Although titanium dioxide (TiO2) has a wide range of potential applications, the photocatalytic performance of TiO2 is limited by both its limited photoresponse range and fast recombination of the photogenerated charge carriers. In this work, the preparation of nitrogen (N)-doped TiO2 accompanied by the introduction of oxygen vacancy (Vo) has been achieved via a facile annealing treatment with urea as the N source. During the annealing treatment, the presence of urea not only realizes the N-doping of TiO2 but also creates Vo in N-doped TiO2 (N-TiO2), which is also suitable for commercial TiO2 (P25). Unexpectedly, the annealing treatment-induced decrease in the specific surface area of N-TiO2 is inhibited by the N-doping and, thus, more active sites are maintained. Therefore, both the N-doping and formation of Vo as well as the increased active sites contribute to the excellent photocatalytic performance of N-TiO2 under visible light irradiation. Our work offers a facile strategy for the preparation of N-TiO2 with Vo via the annealing treatment with urea. [ABSTRACT FROM AUTHOR]

Surface‐enhanced Raman scattering (SERS) technology is a cutting‐edge analytical tool for molecule detection. Attractive SERS performance has been achieved on noble metal nanostructures; however these substrates usually suffer from difficulties of direct adjusting of the physical structures to achieve tunable SERS performance. Studies on semiconductor oxides have revealed that attractive SERS performance can be obtained on them, but strategies of engineering material properties for SERS performance improvement still pose a challenge. Here, an electrically programmable SERS substrate is prepared by depositing hydrothermally synthesized MoOx/Ag hybrids within electrodes as the SERS active region. In the experiment, an electrical field is applied on the electrodes to regulate Ag+ ion migration and redeposition in the MoOx solid electrolyte. Through adjusting the leakage current level, the size of the Ag nanoparticles in the MoOx/Ag hybrids is electrically controlled. The SERS performance of the substrate is evaluated using rhodamine 6G as the Raman reporter. The results evidence that Raman enhancement factors of 1.13 × 105, 4.75 × 105, and 1.04 × 106 can be obtained by programming the leakage current level to 10−7, 10−5, and 10−3 A, respectively. A maximum detection limit of 10−8 m is achieved on the 10−3 A substrate. [ABSTRACT FROM AUTHOR]

Plane-wave ultrasound imaging has ultra-fast temporal resolution and can image at frame rates exceeding 1 kHz, enabling breakthrough technologies like shear wave elastography. However, the imaging process of this technology lacks focus and poor imaging quality and usually requires beamforming technology to assist imaging, such as Coherent Plane-Wave Compounding (CPWC). The imaging quality of this method is often directly related to the number of beams, sacrificing the time advantage of single-beam plane wave imaging. This study proposes a Wavelet-based Generative Adversarial Network for Super-Resolution (WSRGAN) to meet the growing demand for high-quality imaging of single-beam plane waves. WSRGAN uses the encoding and decoding network as the generator and uses wavelet transform to replace the sampling process. Furthermore, we further designed adaptive wavelet attention to enable the model to focus attention on different levels of features at different stages. Wavelet GAN loss was proposed as GAN loss, and a new combined loss function was designed for the generator. The experiment was conducted on the Plane-wave Imaging Challenge in Medical UltraSound (PICMUS) 2016 dataset. On the point target, the Full Width at Half Maximum (FWHM) of WSRGAN reached 0.268 mm to 0.502 mm. On the cyst target, the contrast of WSRGAN reaches 26.156 dB to 37.223 dB. Among invivo targets, the Peak Signal-to-Noise Ratio (PSNR) of WSRGAN is 41.518 dB, and the Structural Similarity Index Measurement (SSIM) is 0.984. Experiments show that each module proposed by the model has a total contribution and is helpful for various experiments. All targets performed well. [ABSTRACT FROM AUTHOR]

Stimuli-responsive hydrogels with fibrous structure are highly promising in biological sensors and actuators because of their fast response rate. In this paper, we first fabricate poly(N-isopropylacrylamide) based hydrogels consisting of electrospun nanofibers and applied them as hydrogel matrices to introduce doped poly(aniline) (PANI) via in-situ polymerization. Regardless of the PANI introduced, the fast thermal-responsive feature brought by the fibrous structure is maintained successfully. The continuous channel for electron transfer is provided by PANI located at fibers' surfaces and inside fibers. The effect of PANI incorporated in hydrogel matrices on: 1) fiber morphology in both swollen and contracted states; 2) swelling/contraction capability of the hydrogels and 3) conductivity of the hybrid hydrogels are investigated. The electric conductive properties of this hybrid hydrogel vary consistently with its swelling degree in response to temperature alternation. Subsequently, an evaluation system, aiming at general understanding and comparison of both conductive and responsive capabilities for this type of hybrid hydrogel, is established. This evaluation system is applied to forecast their potential applications based on corresponding thermal-responsive and conductive properties. [Display omitted] • Introduction of PANI into PNIPAM-based nanofibers via in-situ polymerization. • Reservation of the thermal responsiveness and electrical conductivity. • Correlation of the thermal responsiveness and electrical conductivity of the PNIPAM/PANI hybrid hydrogels. • Establishment of the thermal responsiveness-electrical conductivity model to guide the potential applications. [ABSTRACT FROM AUTHOR]

Ammonia (NH 3) volatilization is the main pathway, by which nitrogen (N) losses from calcareous and alkaline soils occur, and is responsible for economic losses and environmental hazards. We hypothesize that the application of biochar and urease inhibitor (NBPT) can mitigate NH 3 production from urea by reducing its hydrolysis and the abundance of related microbial genes. To clarify this hypothesis, soil N fluxes and the genes controlling hydrolysis and nitrification were investigated under the combined application of urea (0, 75, 150, 225 and 300 kg N ha−1), biochar (7.5 Mg ha−1) and NBPT (2 %) for maize under field conditions. Soil moisture, temperature, pH, mineral N, NH 3 , urease activity (UA) and N cycle related genes (ureC , amoB and amoA) were quantified each 6–17 days during two growing seasons. The combined application of NBPT and biochar reduced NH 3 by 13% of the control, which is twofold higher than the separate additions. All investigated parameters were raised with increasing N rate except pH, which was reduced. Biochar and NBPT mediated these effects of N fertilizer by increasing the soil pH, genes abundance, ammonium and nitrate contents, and reducing urea hydrolysis. Biochar maximized the ammonium and nitrate contents one week and three weeks following the N urea application, respectively. Accordingly, NH 3 and UA peaked directly after N fertilization; nevertheless, NBPT delayed the peaks for three weeks and reduced their intensity by 24 % and 36 %, respectively, under the addition of 300 kg N ha−1. NBPT reduced ureC and amoB genes abundance by 14 % and 8 %, respectively, and increased amoA by 3 %. Biochar increased amoA and amoB abundance and nitrate content, while reduced the ureC gene. Biochar and/or NBPT reduced the negative effects of the soil pH on ureC gene. NBPT mitigated the reduction effects of pH on the amoB and amoA genes. In conclusion, NBPT mitigated NH 3 emission by decreasing the ureC gene and UA, whereas biochar had a synergistic effect with NBPT by increasing amoB and amoA abundance and accelerating nitrification. • Combined addition of biochar and urease inhibitor mitigated ammonia emission. • Nitrogen fertilizer increased the abundance of ureC , amoB and amoA genes. • Biochar augmented both amoB and amoA genes and accelerated nitrification. • Urease inhibitor reduced the abundances of ureC , amoB genes copies. • Urease inhibitor decreased the promoting effect of soil moisture on ureC and amoA. [ABSTRACT FROM AUTHOR]

A UV-initiated crosslinking agent was incorporated in a poly(N-isopropylacrylamide) (PNIPAM)-based copolymer. Thermally-responsive hydrogels were then fabricated by the electrospinning of a PNIPAM-based copolymer and subsequently crosslinked under UV-treatment. The morphology of the fibrous structure was well maintained after many temperature induced swelling and de-swelling cycles. Both considerable degree of swelling and de-swelling ratios, along with an excellent response rate, were achieved with temperature variation. The influence of the crosslinker incorporated in the copolymer was investigated in terms of swelling/de-swelling ratios and rate, as well as the compressive strength and viscoelasticity of the hydrogels. Incorporation of crosslinker led to a 15% increase in copolymer molecular weight and 2 °C decrease of the volume phase transition temperature (VPTT). The diameters of fully swollen and shrunk electrospun fibers were around 10 times and 3 times those of as-spun fibers, respectively. Also, compared to as-spun fiber membrane, 4 times swelling in thickness and an unusual 0.6 time shrinking in the length and width are reported and explained for the first time. In terms of response time, both swelling and de-swelling equilibrium were reached within 10 min for samples with 0.7 mm thickness; negligible impact on the response rate was observed when the crosslinker to monomer ratio increased from 100:1 to 100:5. However, the increase of crosslinker ratio showed significant negative impact on equilibrium swelling and de-swelling ratio (about 700% and 15% decrease respectively). A viscoelastic, but close to elastic, behavior in both swelling and de-swelling equilibrium states under small-amplitude oscillatory shear was observed. The results of this work are expected to accelerate research in applications such as actuators and soft robotics. Image 1 • Fabricating PNIPAM-based hydrogels by electrospinning. • Showing the effect of crosslinker ratio on polymer hydrogel properties. • Investigating the effect of crosslinker ratio on response rate and hydrogel deformation ratio. • Studying the rheology and mechanical strength of these PNIPAM-based hydrogels. [ABSTRACT FROM AUTHOR]

Objectives: To explore the performance of low-dose computed tomography (LDCT) with deep learning reconstruction (DLR) for the improvement of image quality and assessment of lung parenchyma. Methods: Sixty patients underwent chest regular-dose CT (RDCT) followed by LDCT during the same examination. RDCT images were reconstructed with hybrid iterative reconstruction (HIR) and LDCT images were reconstructed with HIR and DLR, both using lung algorithm. Radiation exposure was recorded. Image noise, signal-to-noise ratio, and subjective image quality of normal and abnormal CT features were evaluated and compared using the Kruskal–Wallis test with Bonferroni correction. Results: The effective radiation dose of LDCT was significantly lower than that of RDCT (0.29 ± 0.03 vs 2.05 ± 0.65 mSv, p < 0.001). The mean image noise ± standard deviation was 33.9 ± 4.7, 39.6 ± 4.3, and 31.1 ± 3.2 HU in RDCT, LDCT HIR-Strong, and LDCT DLR-Strong, respectively (p < 0.001). The overall image quality of LDCT DLR-Strong was significantly better than that of LDCT HIR-Strong (p < 0.001) and comparable to that of RDCT (p > 0.05). LDCT DLR-Strong was comparable to RDCT in evaluating solid nodules, increased attenuation, linear opacity, and airway lesions (all p > 0.05). The visualization of subsolid nodules and decreased attenuation was better with DLR than with HIR in LDCT but inferior to RDCT (all p < 0.05). Conclusion: LDCT DLR can effectively reduce image noise and improve image quality. LDCT DLR provides good performance for evaluating pulmonary lesions, except for subsolid nodules and decreased lung attenuation, compared to RDCT-HIR. Clinical relevance statement: The study prospectively evaluated the contribution of DLR applied to chest low-dose CT for image quality improvement and lung parenchyma assessment. DLR can be used to reduce radiation dose and keep image quality for several indications. Key Points: • DLR enables LDCT maintaining image quality even with very low radiation doses. • Chest LDCT with DLR can be used to evaluate lung parenchymal lesions except for subsolid nodules and decreased lung attenuation. • Diagnosis of pulmonary emphysema or subsolid nodules may require higher radiation doses. [ABSTRACT FROM AUTHOR]

Research on highly efficient nitrogen and sulfur co-doped carbon materials is crucial for the development of Fe-based non-noble metal electrocatalysts (NNMEs) as alternatives to platinum-group metal-based electrocatalysts for the oxygen reduction reaction (ORR) in fuel cells. In this work, complexes were derived from iron salt and biomass ligands, subsequently mixed with active carbon nanoparticles (NPs) and pyrolyzed at 800 °C to obtain the resulting electrocatalysts Fe/NSC (800) and Fe/NC (800). Through screening the synthetic parameters, it was found that the N and S co-decorated Fe-based electrocatalyst of Fe/NSC (800) displays better ORR performances in terms of the onset potential (Eonset) and the half-wave potential (E1/2) than those of the Fe-free electrocatalyst of NSC (800) and the N-doped electrocatalyst of Fe/NC (800). The improved ORR activity can be mainly ascribed to the FeN4 active sites, as well as the additional S-doping within the carbon matrixes. Additionally, Fe/NSC (800) displays good durability superior to that of 20 wt% Pt/C in 0.1 M KOH solution. This synthetic approach is beneficial for the synthesis of NNMEs with biomass ligands for boosting the ORR performances in an alkaline solution. [ABSTRACT FROM AUTHOR]

BACKGROUND: Pulse-inversion-based tissue harmonic imaging has been utilized for many years because it can effectively eliminate the harmonic leakage and produce low side-lobe. However, the pulse inversion method is sensitive to imaging object movements, which may result in motion artifacts. Spatial resolution and contrast were limited. OBJECTIVE: To improve ultrasound image quality by a new pulse-inversion-based tissue harmonic imaging technique. METHODS: Continuous wavelet transform is applied to investigate the correlation between mother wavelet and the received echoes from two opposite pulses. To get a better correlation, a novel mother wavelet named 'tissue wavelet' is designed based on the Khokhlov-Zabolotskaya- Kuznetsov (KZK) wave equation. Radio frequency data were obtained from open Ultrasonix SonixTouch imaging system. Experiments were carried on ultrasonic tissue phantom, human carotid artery and human liver. RESULTS: The average improvement of lateral spatial resolution is 49.52% compared to pulse-inversion-based tissue second-harmonic Imaging (PIHI). Contrast ratio (CR) and contrast-to-noise ratio (CNR) increased by 5.55 dB and 1.40 dB over PIHI. Tissue wavelet performs better than Mexh and Morl wavelet in lateral spatial resolution, CR, and CNR. CONCLUSION: The proposed technique effectively improves the imaging quality in lateral spatial resolution, CR, and CNR. [ABSTRACT FROM AUTHOR]

Organic agriculture plays a positive role in promoting genetic diversity, including living organisms, plants, and cultivated crops in the soil. However, few comparative studies reported whether different soil types were suitable for organic cultivation. In this study, loam and clay-loam soils under continuous organic cultivation were analyzed. The results showed that there were no significant differences between two soil types in soil pH, bulk density, total porosity, moisture content and three soil phases. The capillary porosity and organic matter content of loam were significantly higher than those of clay-loam. Compared with clay-loam soil, the contents of total nitrogen, phosphorus, potassium, calcium, zinc and silicon in loam soil were also significantly higher. The microbial diversity was higher in loam and the dominant microbes differed between the two soils. Glycosyl transferases and carbohydrate esterases were enriched in loam, whereas glycoside hydrolases and carbohydrate-binding modules were enriched in clay loam. The potato yield in loam was significantly higher than that in clay loam. Among the tuber quality indicators, the protein content of potatoes in loam was higher than that in clay-loam, but the reducing sugar content was lower for loam than for clay-loam. In conclusion, compared with clay loam, loam was more suitable for organic cultivation of potatoes on account of the high contents of nitrogen, phosphorus, and potassium and the rich microbial community, thus promoting a high yield of tubers. This study provided a theoretical reference for the selection of soil type suitable for organic cultivation. [ABSTRACT FROM AUTHOR]

Organic agriculture plays a positive role in promoting genetic diversity, including living organisms, plants, and cultivated crops in the soil. However, few comparative studies reported whether different soil types were suitable for organic cultivation. In this study, loam and clay-loam soils under continuous organic cultivation were analyzed. The results showed that there were no significant differences between two soil types in soil pH, bulk density, total porosity, moisture content and three soil phases. The capillary porosity and organic matter content of loam were significantly higher than those of clay-loam. Compared with clay-loam soil, the contents of total nitrogen, phosphorus, potassium, calcium, zinc and silicon in loam soil were also significantly higher. The microbial diversity was higher in loam and the dominant microbes differed between the two soils. Glycosyl transferases and carbohydrate esterases were enriched in loam, whereas glycoside hydrolases and carbohydrate-binding modules were enriched in clay loam. The potato yield in loam was significantly higher than that in clay loam. Among the tuber quality indicators, the protein content of potatoes in loam was higher than that in clay-loam, but the reducing sugar content was lower for loam than for clay-loam. In conclusion, compared with clay loam, loam was more suitable for organic cultivation of potatoes on account of the high contents of nitrogen, phosphorus, and potassium and the rich microbial community, thus promoting a high yield of tubers. This study provided a theoretical reference for the selection of soil type suitable for organic cultivation. [ABSTRACT FROM AUTHOR]

FeCo-based non-noble metal electrocatalysts (NNMEs) of FeCo/MCS-NPCS was fabricated by immobilization of hemin on mesoporous carbon shells modified N-doped porous carbon spheres (MCS-NPCS). The obtained FeCo/MCS-NPCS exhibits a half-wave potential (E 1/2) of 0.851 ​V versus the reversible hydrogen electrode (vs. RHE) and a limited-diffusion current density (J L) of 5.45 ​mA ​cm−2. In addition, FeCo/MCS-NPCS shows comparable oxygen reduction reaction (ORR) performances to 20 ​wt% Pt/C in terms of E 1/2 and J L and better electrochemical properties, including the methanol tolerance and durability in alkaline solution. Such outstanding electrochemical activities of FeCo/MCS-NPCS can be ascribed to Fe and/or Co-based nitrides and carbides as well as N-doped carbon matrixes modified with mesoporous carbon shells. This research introduces a promising path to design and synthesize highly efficient FeCo–N–C electrocatalysts towards ORR. [Display omitted] • MCS-NPCS was fabricated by modifying ZIF-67 with polydopamine (PDA) and tetraethoxysilane (TEOS). • FeCo/MCS-NPCS was obtained by supporting hemin over the MCS-NPCS followed by pyrolysis and acid-leaching. • FeCo/MCS-NPCS decorated with mesoporous carbon shells are in favor of improving the ORR performance in alkaline solution. • FeCo/MCS-NPCS displays comparable ORR performance and better durability relative to commercial Pt/C in alkaline solution. [ABSTRACT FROM AUTHOR]

Objective: To investigate the accuracy, diagnostic confidence, and interobserver agreement of subtraction coronary CT angiography (CCTA) versus invasive coronary angiography on 320-row CT in coronary segments with severe or non-severe calcification. Materials/methods: Sixty-four patients (33 men, 66.6 ± 8.2 years) with suspected coronary artery disease (CAD) were prospectively enrolled from October 2019 to June 2020. The cross-sectional circumferential extent of calcification was used to classify calcified segments as non-severely (< 180°) or severely calcified (≥ 180°). Three independent, blinded radiologists evaluated the severity of coronary stenosis. Interobserver agreement was evaluated using Fleiss' kappa (κ). A multiple-reader multiple-case receiver operating characteristic (ROC) method was conducted, and diagnostic accuracy was measured using the mean areas under the ROC curves (AUCs), with ≥ 50% stenosis as a cut-off. Diagnostic confidence, diagnostic accuracy, and interobserver agreement were compared between CCTA with or without subtraction information in severely and non-severely calcified segments. Results: In cases with severe calcification (51 patients, 146 segments), CCTA with subtraction information achieved better diagnostic accuracy (per-patient AUC: 0.73 vs 0.57, p = 0.03; per-segment AUC: 0.85 vs 0.62, p = 0.01), diagnostic confidence (3.7 vs 2.6, p < 0.001), and interobserver agreement (κ: 0.59 vs 0.30). Diagnostic accuracy (per-patient AUC: 0.81 vs 0.93, p = 0.30; per-patient AUC: 0.79 vs 0.82, p = 0.54) was not increased in cases with non-severe calcification (13 patients, 190 segments). Conclusions: CCTA with subtraction information achieved better diagnostic accuracy in cases of severe calcification (circumferential extent ≥ 180°). However, for non-severe calcification (circumferential extent < 180°), the effect of calcium subtraction was unclear, as it did not improve diagnostic accuracy. Key Points: • Subtraction coronary CT angiography achieves better diagnostic accuracy, higher diagnostic confidence, and increased interobserver agreement for severe calcification (circumferential extent ≥ 180°). • Calcium subtraction does not improve the diagnostic accuracy of coronary CT angiography for calcification with a circumferential extent of < 180°. [ABSTRACT FROM AUTHOR]

Atomically dispersed Fe−N−C electrocatalysts have displayed excellent catalytic performances towards the oxygen reduction reaction (ORR), while the identification of the genuine active sites remains a challenge. Herein, we report a Fe−N−C electrocatalyst of FeSA/HNPC featuring single‐atomic FeN4 sites on hierarchically N‐doped porous carbon (HNPC), which shows a very competitive ORR activity in alkaline solution even at a low electrocatalyst loading of 0.2 mg cm−2 on the working electrode. A comparison of energy barriers in ORR reveals that the single‐atomic FeN4 active sites in FeSA/HNPC existing in the form of pyrrole‐N4−Fe is more favorable than that of pyridine‐N4−Fe for the enhanced ORR activity. Understanding the nature of FeN4 active sites will greatly benefit the design of Fe−N−C electrocatalysts with highly effective ORR performances. [ABSTRACT FROM AUTHOR]

Surface-enhanced Raman scattering (SERS) technique is a powerful spectrum analysis technique for the ultra-low molecular trace detection. Conventionally, noble metals like silver (Ag) and gold (Au) are used to prepare the SERS substrates; however, limitations of complicated experimental designs and sophisticated process steps impede their wide applications in practice. Recently, metal oxides arise as a promising material for SERS application, but relatively weak Raman signal enhancement and poor material stability still pose as a challenge. Here, a UV-light-assisted fabrication of MoO3−x/silver nanoparticles (MoO3−x/Ag NPs) film is proposed. In the experiment, the sub-transition-metal-oxide of MoO3−x was used as the Raman chemical enhancement substrate as well as the reducing agent. Through the spin-coating of MoO3−x layer on the silicon substrate and UV-light-assisted reduction of silver nitride (AgNO3) on the MoO3−x layer, a novel MoO3−x/Ag NPs one-layer film was fabricated. Using the Rhodamine B (RhB) as the Raman reporter, SERS measurement shows that enhancement factor (EF) of 1.195 × 106 could be achieved. Moreover, a Raman signal amplifying strategy is further demonstrated by constructing MoO3−x/Ag NPs multi-layer films. And result evidences that maximum gain of 2.07 for the RhB Raman peak at 1280 cm−1 can be obtained on the MoO3−x/Ag NPs three-layer film when referred to that on the MoO3−x/Ag NPs one-layer film. Meanwhile, the EF of the MoO3−x/Ag NPs three-layer film is also improved to 2.985 × 106, giving the minimum detectable concentration of 10−9 M. [ABSTRACT FROM AUTHOR]

Solid dynamic deformation and multiphase fluid coupling driven by numerical simulation have manifested their significance for many graphics applications during the past 2 decades. For example, the fluid implicit particle (FLIP) method and shape matching constraint based on position-based dynamics (PBD) have demonstrated their unique graphics strength in fluid and solid animation, respectively. In this paper, we propose a novel integrated approach supporting the seamless unification of FLIP and dynamic shape matching. We devise new algorithms to tackle existing difficulties when handling new phenomena such as high-fidelity fluid–solid interactions, solid deformations, melting and immiscible fluid coupling. The key innovation of this paper is a unified Lagrangian framework that seamlessly blends FLIP- and PBD-based shape matching constraints toward the natural yet flexible coupling between fluid and deformable solid. Within our integrated framework, it enables many complicated fluid–solid phenomena with ease. We conduct various kinds of experiments, all the results demonstrate the advantages of our unified hybrid approach toward visual fidelity, computational efficiency, numerical stability, and application versatility. [ABSTRACT FROM AUTHOR]

Abstract Tin sulfides have attracted significant interests as the anode materials of lithium-ion batteries (LIBs) due to their high capacity and layered structure. However, metal sulfides suffer from a fast capacity decay caused by the large volume change during cycling, and poor conductivity. In this work, we report on a rational design of lamellar nanostructure consisting of N-doped carbon layers, graphene nanosheets, and SnS nanoparticles. The SnS/graphene nanosheets with and without N-carbon coating have been investigated as the anode for LIBs to study the structure effect. It is found that N-carbon/SnS/graphene nanosheets deliver a high reversible capacity of 840 mA h g−1 after 150 cycles at a current density of 100 mA g−1 and higher rate properties in comparison to SnS/graphene. The improved electrochemical performances are attributed to the special lamellar structure with a combined synergic effect derived from the N-carbon coating layers and graphene nanosheets, which conduce to a faster lithium diffusion dynamics in the composite nanosheets, which has been analyzed by electrochemical impedance spectroscopy. This work propose an efficient pathway to manipulate metal sulfides based nanomaterials for use as anodes in LIBs with enhanced lithium storage performances. [ABSTRACT FROM AUTHOR]

The remaining authors declare no relationships with any companies whose products or services may be related to the subject matter of the article. The original article can be found online at https://doi.org/10.1007/s00330-021-08092-5. [Extracted from the article]

Five complexes have been synthesized by the reaction of lanthanide(III) nitrate with 2-thenoyltrifluoroacetone (HTTA) and p-hydroxybenzoic acid (L). The complexes have been characterized by elemental analysis, molar conductivity, FT-IR, UV-Vis, 1H NMR, TG-DTA, XPS, and transmission electron microscope. The general formula of the complexes is Na[Ln(TTA)3L] (Ln = La3+, Ce3+, Nd3+, Eu3+, Er3+). The antibacterial activities indicate that all five complexes exhibit antibacterial ability against Escherichia coli and Staphylococcus aureus with broad antimicrobial spectrums. The antitumor activity of the five complexes against K562 tumor cell in vitro is measured using methyl thiazolyl tetrazolium (MTT) colorimetry. The results show that the complexes induce K562 tumor cell apoptosis, and the complexes exhibit inhibitory effect on leukemia K562 cells. [ABSTRACT FROM AUTHOR]