Durable and self-healing superamphiphobic coatings with high repellency to both cool and hot liquids are successfully prepared on various substrates by the combination of rodlike palygorskite and ...organosilanes via spray-coating. The coatings feature high mechanical, environmental and chemical durability, and are self-healing.
Gait recognition is of great importance in the fields of surveillance and forensics to identify human beings since gait is the unique biometric feature that can be perceived efficiently at a ...distance. However, the accuracy of gait recognition to some extent suffers from both the variation of view angles and the deficient gait templates. On one hand, the existing cross-view methods focus on transforming gait templates among different views, which may accumulate the transformation error in a large variation of view angles. On the other hand, a commonly used gait energy image template loses temporal information of a gait sequence. To address these problems, this paper proposes multi-task generative adversarial networks (MGANs) for learning view-specific feature representations. In order to preserve more temporal information, we also propose a new multi-channel gait template, called period energy image (PEI). Based on the assumption of view angle manifold, the MGANs can leverage adversarial training to extract more discriminative features from gait sequences. Experiments on OU-ISIR, CASIA-B, and USF benchmark data sets indicate that compared with several recently published approaches, PEI + MGANs achieves competitive performance and is more interpretable to cross-view gait recognition.
Gait is a unique biometric feature that can be recognized at a distance; thus, it has broad applications in crime prevention, forensic identification, and social security. To portray a gait, existing ...gait recognition methods utilize either a gait template which makes it difficult to preserve temporal information, or a gait sequence that maintains unnecessary sequential constraints and thus loses the flexibility of gait recognition. In this paper, we present a novel perspective that utilizes gait as a deep set , which means that a set of gait frames are integrated by a global-local fused deep network inspired by the way our left- and right-hemisphere processes information to learn information that can be used in identification. Based on this deep set perspective, our method is immune to frame permutations , and can naturally integrate frames from different videos that have been acquired under different scenarios, such as diverse viewing angles, different clothes, or different item-carrying conditions. Experiments show that under normal walking conditions, our single-model method achieves an average rank-1 accuracy of 96.1 percent on the CASIA-B gait dataset and an accuracy of 87.9 percent on the OU-MVLP gait dataset. Under various complex scenarios, our model also exhibits a high level of robustness. It achieves accuracies of 90.8 and 70.3 percent on CASIA-B under bag-carrying and coat-wearing walking conditions respectively, significantly outperforming the best existing methods. Moreover, the proposed method maintains a satisfactory accuracy even when only small numbers of frames are available in the test samples; for example, it achieves 85.0 percent on CASIA-B even when using only 7 frames. The source code has been released at https://github.com/AbnerHqC/GaitSet .
Exosomes: An emerging factor in atherosclerosis Wang, Yanan; Xie, Yingyu; Zhang, Ao ...
Biomedicine & pharmacotherapy,
July 2019, 2019-Jul, 2019-07-00, 20190701, 2019-07-01, Letnik:
115
Journal Article
Recenzirano
Odprti dostop
Atherosclerosis is the main reason for morbidity and death caused by cardiovascular disease which leads to approximately 20% of total death around the world. Exosomes secreted by the cells is a kind ...of extracellular vesicles with lipid bilayer structure, containing a variety of cell specific lipid, nucleic acid and protein, involved in intercellular communication, plays an important role in different physiological and pathological process. In recent years, with the deepening of research, the role of exosomes in cardiovascular diseases has received extensive attention. This review summarizes the roles of exosomes and exosome-derived from microRNAs, proteins and DNA as biomarkers in the development of atherosclerosis, and explores the mechanism of exosome-mediated intercellular crosstalk in atherosclerosis, providing potential roles for diagnosis and treatment.
Inspired by the self-cleaning and water-repellent properties of plants and animals in the natural world, superhydrophobic and superoleophobic materials develop quickly, and are of great interest in ...academic and industrial areas. Although various chemicals have been used, silanes and silicones play very important roles in the preparation of superhydrophobic and superoleophobic materials. Approximately 25% of the literature about superhydrophobic and superoleophobic materials is based on silanes and silicones. Thus, we believe that an exhaustive literature review from the viewpoint of silane and silicone chemistry is now pertinent to give an overview of the recent progress about their roles in the preparation of superhydrophobic and superoleophobic materials. First of all, we hope to overview the roles of silanes and silicones in constructing micro-/nanostructures, decreasing the surface energy and/or as binders for the fabrication of superhydrophobic and superoleophobic surfaces. We will then focus on the roles of silanes and silicones in the formation of superhydrophobic and superoleophobic particles, sponges and aerogels. In the conclusions, we will summarize the roles of silanes and silicones in forming superhydrophobic and superoleophobic materials, and the challenges in the field. Overall, this review will hopefully help readers to use silanes and silicones dexterously in the design of novel superhydrophobic and superoleophobic materials.
The roles of silanes and silicones in forming superhydrophobic and superoleophobic materials are summarized, and the challenges are also listed.
Magnetic, durable, and superhydrophobic polyurethane (PU) sponges were fabricated by chemical vapor deposition (CVD) of tetraethoxysilane (TEOS) to bind the Fe3O4 nanoparticles tightly on the sponge ...and then dip-coating in a fluoropolymer (FP) aqueous solution. The sponges were characterized using scanning electron microscopy and other analytical techniques. The effects of CVD time of TEOS and FP concentration on wettability, mechanical properties, oil absorbency, and oil/water selectivity of the sponges were also investigated. The sponges exhibit fast magnetic responsivity and excellent superhydrophobicity/superoleophilicity (CAwater = 157° and CAoil ≈ 0°). The sponges also show very high efficiency in oil/water separation and could, driven by a magnet, quickly absorb floating oils on the water surface and heavy oils under water. Moreover, the PU@Fe3O4@SiO2@FP sponges could be used as membranes for oil/water separation and for continuous separation of large amounts of oil pollutants from the water surface with the help of a pump. The in turn binding of Fe3O4 nanoparticles, SiO2, and FP can also improve mechanical properties of the PU sponge. The sponges maintain the superhydrophobicity even when they are stretched with 200% strain or compressed with 50% strain. The sponges also show excellent mechanical stability, oil stability, and reusability in terms of superhydrophobicity and oil absorbency. The magnetic, durable, and superhydrophobic PU sponges are very promising materials for practical oil absorption and oil/water separation.
Unlike conventional facial expressions, microexpressions are instantaneous and involuntary reflections of human emotion. Because microexpressions are fleeting, lasting only a few frames within a ...video sequence, they are difficult to perceive and interpret correctly, and they are highly challenging to identify and categorize automatically. Existing recognition methods are often ineffective at handling subtle face displacements, which can be prevalent in typical microexpression applications due to the constant movements of the individuals being observed. To address this problem, a novel method called the Facial Dynamics Map is proposed to characterize the movements of a microexpression in different granularity. Specifically, an algorithm based on optical flow estimation is used to perform pixel-level alignment for microexpression sequences. Each expression sequence is then divided into spatiotemporal cuboids in the chosen granularity. We also present an iterative optimal strategy to calculate the principal optical flow direction of each cuboid for better representation of the local facial dynamics. With these principal directions, the resulting Facial Dynamics Map can characterize a microexpression sequence. Finally, a classifier is developed to identify the presence of microexpressions and to categorize different types. Experimental results on four benchmark datasets demonstrate higher recognition performance and improved interpretability.
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•Combination of epoxy paint and superamphiphobic coating provides long-term protection for Mg alloys.•Mg alloy shows high stability during 70 d 3.5 wt% NaCl immersion and 35 d neutral ...salt spray tests.•Differences of superhydrophobic and superamphiphobic coatings in anti-corrosion are revealed.•Corrosion resistance of super anti-wetting coatings in neutral salt spray test is improved.
Magnesium (Mg) alloys have many unique properties but suffer from poor corrosion resistance. Effective anti-corrosion strategies are highly desirable for widespread applications of Mg alloys. Bioinspired super anti-wetting coatings are promising for metal protection, but are limited by some issues. Here, we report a bi-layer superamphiphobic coating for efficient protection of Mg alloy by sequentially spray-coating a conventional epoxy anti-corrosion coating and a superamphiphobic coating (perfluorodecyl polysiloxane modified SiO2). The coating showed excellent anti-corrosion performance owing to high superamphiphobicity and “synergistic effect” of the bi-layer structure. The coating retained excellent anti-corrosion performance even after 70 d immersion and 35 d neutral salt spray tests. The long-term anti-corrosion performance is superior to a superhydrophobic coating with similar initial anti-corrosion performance, and better than reported and commercial anti-corrosion coatings. This is because the coating maintained high superamphiphobicity in the corrosion tests owing to high chemical stability of the C-F groups and easy roll off of small NaCl drops. Hence, the contact area and contact time of NaCl on the coating are limited. So, the coating could effectively block diffusion of corrosive substances, providing long-lasting efficient protection. We believe that the strategy will shed a new light on designing novel anti-corrosion coatings.
Superhydrophobic coatings are expected to solve the rain attenuation issue of 5G radomes. However, it is very challenging to design and construct such superhydrophobic coatings with good impalement ...resistance, mechanical robustness, and weather resistance, which remains as one of the main bottlenecks hindering their practical applications. Here, we report the design of superhydrophobic coatings with all these merits mentioned above by spray-coating a suspension of adhesive/fluorinated silica core/shell microspheres onto substrates. The core/shell microspheres are formed by phase separation of the adhesive and adhesion between the adhesive and fluorinated silica nanoparticles. The coatings have an approximately isotropic three-tier hierarchical micro-/micro-/nanostructure, a dense but rough surface at the nanoscale, and chemically inert composition with low surface energy. Consequently, the coatings show excellent impalement resistance, mechanical robustness and weather resistance compared with previous studies, and the mechanisms are revealed. Furthermore, we realize large-scale preparation, extension, and practical application of the coatings for efficiently preventing rain attenuation of 5G/weather radomes. By taking these advantages, we believe that the superhydrophobic coatings have great application potential and market prospect. The findings here will boost preparation and real-world applications of superhydrophobic coatings.
Ultralight, compressible and multifunctional carbon aerogels (UCM aerogels) have broad potential applications in various fields including thermal insulation, oil absorption and electronics. However, ...the preparation of UCM aerogels has been proven to be very challenging. Herein, we report a novel approach for the fabrication of UCM aerogels by pyrolysis of aerogels composed of kapok fibers (KFs), a kind of natural cellulose with a tubular structure. Different from the frequently used freeze-drying approach, the wet KF aerogels can be dried directly in an oven without any shrinkage. The fascinating UCM aerogels feature ultralow density (∼1.0 mg cm −3 ), high compressibility, high electrical conductivity (0.1 S cm −1 ), excellent fire-resistance and very high absorption capacity (147–292 g g −1 ) for organic liquids. Furthermore, the UCM aerogels can be easily endowed with various other functions, e.g. , magnetic responsivity and superhydrophobicity. The successful creation of the UCM aerogels may provide new insights into the design of UCM aerogels for various applications, as the UCM aerogels can be prepared via a very simple procedure.
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