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•A smart anticorrosion system composed of PEO, LDH and slippery layers was produced.•LDH film could effectively seal PEO defects, encapsulate inhibitor and anchor lubricant.•The ...system qualified Mg alloy for durable and self-healing anticorrosion ability.
Inspirations from nature have led to extensive developments of biomimetic nonwetting surfaces and intelligent self-healing technologies toward corrosion protection of metals. Integration of both intriguing features contributes to achieving diversified protections. In this work, we engineered a novel anticorrosion system composed of a plasma electrolytic oxidation (PEO) film, a layered double hydroxide (LDH) film and a lubricant-infused slippery surface on Mg alloy. The PEO film grown in situ on Mg alloy could render a moderate corrosion barrier, and the sandwiched LDH film integrated ternary roles involving loading corrosion inhibitor, anchoring lubricant and sealing PEO defects. The outermost slippery surface exhibited durable repellence against water and also self-reparable capability to surface damage. The robust and self-reparable film barrier coupled with active corrosion inhibition endowed this system with superb anticorrosion performance. The dynamic self-healing processes associated with barrier regeneration and corrosion inhibition were substantiated at microscale using scanning Kelvin probe and scanning vibrating electrode technique, respectively. It is expected that this research would shed light on the design of multifunctional anticorrosion systems for Mg alloy.
Prompt diagnosis of early gastric cancer (EGC) is crucial for improving patient survival. However, most previous computer-aided-diagnosis (CAD) systems did not concretize or explain diagnostic ...theories. We aimed to develop a logical anthropomorphic artificial intelligence (AI) diagnostic system named ENDOANGEL-LA (logical anthropomorphic) for EGCs under magnifying image enhanced endoscopy (M-IEE).
We retrospectively collected data for 692 patients and 1897 images from Renmin Hospital of Wuhan University, Wuhan, China between Nov 15, 2016 and May 7, 2019. The images were randomly assigned to the training set and test set by patient with a ratio of about 4:1. ENDOANGEL-LA was developed based on feature extraction combining quantitative analysis, deep learning (DL), and machine learning (ML). 11 diagnostic feature indexes were integrated into seven ML models, and an optimal model was selected. The performance of ENDOANGEL-LA was evaluated and compared with endoscopists and sole DL models. The satisfaction of endoscopists on ENDOANGEL-LA and sole DL model was also compared.
Random forest showed the best performance, and demarcation line and microstructures density were the most important feature indexes. The accuracy of ENDOANGEL-LA in images (88.76%) was significantly higher than that of sole DL model (82.77%, p = 0.034) and the novices (71.63%, p<0.001), and comparable to that of the experts (88.95%). The accuracy of ENDOANGEL-LA in videos (87.00%) was significantly higher than that of the sole DL model (68.00%, p<0.001), and comparable to that of the endoscopists (89.00%). The accuracy (87.45%, p<0.001) of novices with the assistance of ENDOANGEL-LA was significantly improved. The satisfaction of endoscopists on ENDOANGEL-LA was significantly higher than that of sole DL model.
We established a logical anthropomorphic system (ENDOANGEL-LA) that can diagnose EGC under M-IEE with diagnostic theory concretization, high accuracy, and good explainability. It has the potential to increase interactivity between endoscopists and CADs, and improve trust and acceptability of endoscopists for CADs.
This work was partly supported by a grant from the Hubei Province Major Science and Technology Innovation Project (2018-916-000-008) and the Fundamental Research Funds for the Central Universities (2042021kf0084).
In the present work, the early-stage growth behaviour of titania on titanium (Ti) substrate during plasma electrolytic oxidation (PEO) process in an aqueous electrolyte rich in Ca and P was ...investigated. Microstructural characterization reveals the dramatic evolutions of morphology, porosity, phase component and chemical composition of titania during the early stage of PEO process. The PEO coating initially exhibits ultrafine pores with a completely amorphous structure after oxidation for 5 s, which displays a relatively low Ca/P ratio. With the extension of oxidation periods, titania gradually transforms to grooved morphology with an increased Ca/P ratio, which mainly consists of crystalline anatase phase. Finally, with the prolongation of oxidation period to 1 min, titania exhibits porous morphology typical for PEO coating, which comprises of both rutile and anatase crystals. Along with the prolongation of oxidation periods, the surface wettability of titania remains relatively stable whereas the corrosion resistance changes dramatically, which is closely associated with the combined effects of its porosity and thickness. The results of our present work advance the understanding of early-stage growth of titania during the PEO process, which offer theoretical guidance for the controllable synthesis of PEO coating on Ti and its alloys.
•The growth behaviour of titania prior to dielectric breakdown was examined.•Titania initially displays ultrafine pores, transforms to grooved morphology and finally stabilizes as porous structure.•The initial titania is amorphous, which transforms to anatase and finally becomes the mixture of rutile and anatase.•The Ca/P ratio gradually increases with the prolongation of oxidation periods and finally reaches ~0.9.•The combined effect of porosity and thickness results in the dramatic modification of corrosion resistance in titania.
The hydroxyapatite (HA)-based/TiO2-based composite coating was produced through plasma electrolytic oxidation (PEO) method in the present work. The microstructural evolution of the composite coating ...was examined as a function of PEO duration. It was observed that CaP phase initially appears at the cracks of TiO2-based layer in form of plates of micrometre scales after PEO duration of 5 min and then transforms to the hybrid of plates and floccules, which finally convert to clusters composed of nano-sized plates by self-assembly. After 15 min oxidation, a two-layered composite coating was revealed, including TiO2-based inner layer and HA-based outer layer. It is also noticed that the thickness of HA-based layer continuously increases as the oxidation period extends whereas both the thickness of TiO2-based layer beneath the HA-based layer and the coverage rate of CaP phase on TiO2-based layer remain relatively stable at the late stage of PEO process. The microstructural variation inevitably affects the biocompatibilities and corrosion properties of the composition coatings. With the extension of oxidation periods, an increased amount of CaP phase was produced in the composite coating, which thus results in an improved corrosion resistance due to its insulation property, hydrophobicity and physical barrier effect. Meanwhile, the enhanced biocompatibility of the composite coating could also be achieved with the prolongation of PEO duration, which is associated with the high bioactivity of CaP phase.
•The hydroxyapatite/TiO2 composite coating has been successfully produced through plasma electrolytic oxidation.•The formation of hydroxyapatite is closely associated with cracks in the TiO2-based layer.•The presence of hydroxyapatite retards the growth of underlying TiO2.•The coverage rate of hydroxyapatite initially increases dramatically and finally remains stable at approximately 80%.•An increased amount of hydroxyapatite results in an improved corrosion resistance and biocompatibility of the coating.
To investigate the impact of the computer-assisted system on esophagogastroduodenoscopy (EGD) training for novice trainees in a prospective randomized controlled trial.
We have constructed a ...computer-aided system (CAD) using retrospective images based on deep learning which could automatically monitor the 26 anatomical landmarks of the upper digestive tract and document standard photos. Six novice trainees were allocated and grouped into the CAD group and control group. Each of them took the training course, pre and post-test, and EGD examination scored by two experts. The CAD group was trained with the assistance of the CAD system and the control group without.
Both groups achieved great improvements in EGD skills. The CAD group received a higher examination grading score in the EGD examination (72.83 ± 16.12 vs. 67.26 ± 15.64,
= 0.039), especially in the mucosa observation (26.40 ± 6.13 vs. 24.11 ± 6.21,
= 0.020) and quality of collected images (7.29 ± 1.09 vs. 6.70 ± 1.05). The CAD showed a lower blind spot rate (2.19 ± 2.28 vs. 3.92 ± 3.30,
= 0.008) compared with the control group.
The artificial intelligence assistant system displayed assistant capacity on standard EGD training, and assisted trainees in achieving a learning curve with high operation quality, which has great potential for application.
This trial is registered at https:/clinicaltrials.gov/, number NCT04682821.
Water electrolysis is of great importance for high-efficient hydrogen production. Replacing noble metal-based electrocatalysts by highly efficient and inexpensive non-noble metal based catalysts is ...critical for the practical application of these technologies. Here we report a novel hybrid of nitrogen-doped carbon shell coated CoP nanocrystals encapsulated in porous nitrogen-doped carbon substrate (CoP/PNC), which is synthesized through sol-gel and consequent pyrolysis-oxidation-phosphorization method. The obtained CoP/PNC exhibits promising electrocatalytic performance toward HER and OER due to the synergistic effect between N-doped carbon and CoP nanocrystals. When the CoP/PNC catalyst is applied in a two-electrode water splitting device, the cell potential at 10 mA cm−2 could be as low as 1.68 V. Besides, it still remains current retention of 78.7% after continuous run for 24 h.
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S-doped graphene oxide hybrid nanosheets are prepared by a facile in situ-polymerization method. The electrochemical performance is evaluated using cyclic voltammetry, galvanostatic charge/discharge ...techniques and impedance spectroscopy in 2 M KOH. As an electroactive material, it exhibits good capacitive performance in alkali aqueous electrolyte, high specific capacitance (up to 296 F g−1) at a current density of 0.3 A g−1, which is calculated via charge/discharge curve in three electrode systems. The electrical conductivity is also measured. More importantly, over 91.86% of the long-term stability is retained after repeating the galvanostatic charge/discharge over 4000 cycles. Furthermore, larger energy density (up to 148 W h kg−1 at a power density of 41.6 W kg−1) of the GO-TB-based three-electrode device is obtained with alkali aqueous electrolytes.
•S-doped graphene oxide hybrid nanosheets were prepared by a facile method.•Hybrid nanosheets exhibits good capacitive performance.•Large energy density of the GO-TB-based three-electrode device was obtained.
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