Owing to their significant physiological functions, especially as selective relays for translocation of physiological relevant species through cellular membranes, natural ion channels play important ...role in the living organisms. During the last decades, the field of self‐assembled ion channels has been continuously developed. Convergent multidimensional self‐assembly strategies have been used for the synthesis of unimolecular channels or non‐covalent self‐organized channels, designed to mimic natural ion channel proteins and for which a rich array of interconverting or adaptive channel conductance states can be observed. In this review, we give an overview on the development of various self‐assembled artificial channels in a bottom‐up approach, especially their design, self‐assembly behaviour, transport activity in lipid bilayer membranes, mechanism of transport and comparison with natural ion channels. Finally, we discuss their applications, the potential challenges facing in this field as well as future development and perspectives.
This Review gives an overview of the various types of supramolecular self‐assembled artificial ion‐channels: capsules and cages, macrocyclic stacks, tubular helical architectures.
During the past several years, abundant progresses has been made in the development of immobilized oxidative enzymes with focus on finding new support materials, improving the immobilization methods ...and their applications. Nowadays, immobilized oxidative enzymes are broadly accepted as a green way to face the challenge of high amounts of micropollutants in nature. Among all oxidative enzymes, laccases and horseradish peroxidase were used frequently in recent years as they are general oxidative enzymes with ability to oxidize various types of compounds. Immobilized laccase or horseradish peroxidase are showed better stability, and reusability as well as easy separation from reaction mixture that make them more favorable and economic in compared to free enzymes. However, additional improvements are still essential such as: development of the new materials for immobilization with higher capacity, easy preparation, and cheaper price. Moreover, immobilization methods are still need improving to become more efficient and avoid enzyme wasting during immobilization and enzyme leakage through working cycles.
•Current status of immobilized oxidative enzymes for micropollutants bioremediation.•Immobilized enzymes vs. free enzymes for micropollutants degradation.•Micropollutants bioremediation by immobilized enzymes from analytical points of view.
In this work, the evolution of microstructure and fundamental mechanical properties with Mo concentration in the arc-melted (TiZrNbTa)100-xMox (0 ≤ x ≤ 20) high-entropy alloys (HEAs) are ...investigated. The arc-melted (TiZrNbTa)100-xMox alloys structurally consist of two bcc phases. The change in volume fractions of two phases in the microstructure is insignificant with Mo concentration, at levels of ∼75% for bcc1 and ∼25% for bcc2. The increases in microhardness and Young's modulus of the alloys linearly scale with Mo concentration. To compromise the strength and ductility, the (TiZrNbTa)90Mo10 exhibits an optimal combination of stiffness (E = 137 GPa), compressive yield strength (σy = 1370 MPa) and deformability (εp ≈ 25%). In addition, it is indicated that dislocation widths in bcc lattice of refractory HEAs are insensitive to the alloying complexity, reflecting that the Peierls barrier is excluded as a predominant factor of strengthening. Furthermore, a simple model is proposed to reveal the solid solution hardening (SSH) in bcc refractory HEAs, in which the solid solutions are treated as an imposition of distortion-free and distorted lattices. By applying this model to archived refractory HEAs, the predicted yield strength agrees well with experimentally measured values. It provides a simple empirical tool used for predicting the strength of bcc refractory HEAs and to assist new alloy design.
•Arc-melted (TiZrNbTa)Mo high-entropy alloys (HEAs) consist of two bcc phases in microstructure.•Microhardness and Young's modulus of the alloys increases with Mo concentration.•(TiZrNbTa)90Mo10 exhibits an optimal combination of compressive strength and deformability.•A simple model is proposed to reveal the solid solution hardening in bcc refractory HEAs.•Yield strength predicted with this model is good in agreement with experimental data.
RGB-D salient object detection (SOD) aims to segment the most attractive objects in a pair of cross-modal RGB and depth images. Currently, most existing RGB-D SOD methods focus on the foreground ...region when utilizing the depth images. However, the background also provides important information in traditional SOD methods for promising performance. To better explore salient information in both foreground and background regions, this paper proposes a Bilateral Attention Network (BiANet) for the RGB-D SOD task. Specifically, we introduce a Bilateral Attention Module (BAM) with a complementary attention mechanism: foreground-first (FF) attention and background-first (BF) attention. The FF attention focuses on the foreground region with a gradual refinement style, while the BF one recovers potentially useful salient information in the background region. Benefited from the proposed BAM module, our BiANet can capture more meaningful foreground and background cues, and shift more attention to refining the uncertain details between foreground and background regions. Additionally, we extend our BAM by leveraging the multi-scale techniques for better SOD performance. Extensive experiments on six benchmark datasets demonstrate that our BiANet outperforms other state-of-the-art RGB-D SOD methods in terms of objective metrics and subjective visual comparison. Our BiANet can run up to 80 fps on <inline-formula> <tex-math notation="LaTeX">224\times 224 </tex-math></inline-formula> RGB-D images, with an NVIDIA GeForce RTX 2080Ti GPU. Comprehensive ablation studies also validate our contributions.
Although the photodimerization of acenaphthylene (ACE) has been known for 100 years, the asymmetric cycloaddition of its 1‐substituted derivatives is unknown. Herein, we report a supramolecular ...photochirogenic approach in which a homochiral and photoactive Δ/Λ‐Pd6(RuL3)828+ metal–organic cage (Δ/Λ‐MOC‐16) is used as a supramolecular reactor for the enantioselective exited‐state photocatalysis of 1‐Br‐ACE. Owing to preorganization of the substrates by the supramolecular cage, stereochemical control of the triplet state, and nanospace transfer of energy and chirality, the cycloaddition of ACE proceeded with high selectivity for the formation of anti over syn stereoisomers, whereas the regio‐, stereo‐, and enantioselective cycloaddition of unsymmetrical 1‐Br‐ACE showed effective enantiodifferentiation of a pair of anti head‐to‐head stereoisomers. The enzyme‐mimicking photocatalysis was verified by catalytic turnover, rate enhancement, and competing‐guest inhibition experiments.
Control freak: A photoactive homochiral metal–organic cage (MOC) promoted the stereo‐, regio‐, and enantioselective 2+2 cycloaddition of an acenaphthylene derivative in a supramolecular catalytic sense under sustainable conditions (see picture). The high regio‐ and stereoselectivity resulted from preorganization of the substrates by the supramolecular cage, stereochemical control of the triplet state, and nanospace transfer of energy and chirality.
Video stabilization techniques are essential for most hand-held captured videos due to high-frequency shakes. Several 2D-, 2.5D-, and 3D-based stabilization techniques have been presented previously, ...but to the best of our knowledge, no solutions based on deep neural networks had been proposed to date. The main reason for this omission is shortage in training data as well as the challenge of modeling the problem using neural networks. In this paper, we present a video stabilization technique using a convolutional neural network. Previous works usually propose an off-line algorithm that smoothes a holistic camera path based on feature matching. Instead, we focus on low-latency, real-time camera path smoothing that does not explicitly represent the camera path and does not use future frames. Our neural network model, called StabNet, learns a set of mesh-grid transformations progressively for each input frame from the previous set of stabilized camera frames and creates stable corresponding latent camera paths implicitly. To train the network, we collect a dataset of synchronized steady and unsteady video pairs via a specially designed hand-held hardware. Experimental results show that our proposed online method performs comparatively to the traditional off-line video stabilization methods without using future frames while running about 10 times faster. More importantly, our proposed StabNet is able to handle low-quality videos, such as night-scene videos, watermarked videos, blurry videos, and noisy videos, where the existing methods fail in feature extraction or matching.
We demonstrate that based on NbTa as the base solution, ternary equiatomic HfNbTa and TiNbTa single-phase body-centered-cubic (BCC) solid solutions are achieved at arc-melted alloy ingots. These add ...interesting new members into the group of ternary refractory medium-entropy alloys (RMEAs), previously available only in NbTiZr. Moreover, HfNbTa and TiNbTa are the first two ternary RMEAs that exhibit tensile ductility, with HfNbTa having a combination of yield strength and tensile strain on par with its high-entropy counterpart, the Senkov alloy TiZrHfNbTa. We also show that alloying Hf into the base NbTa solution manifests a much higher strengthening potency compared with Ti. This difference can be rationalized using empirical parameters and models accounting for the size and modulus misfits among constituent elements.
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•Arc-melted equiatomic HfNbTa and TiNbTa alloys formed BCC solid solutions.•HfNbTa and TiNbTa are the first two ternary RMEAs that exhibit tensile ductility.•Alloying Hf into NbTa solution shows higher strengthening potency compared with Ti.•This difference can be rationalized using empirical parameters.•Fictive lattice model is also applicable to these RMEAs.
Hydrocolloids are among the most commonly used ingredients in the food industry. They function as thickeners, gelling agents, emulsifiers, stabilizers, fat replacers, clarifying agents, flocculating ...agents, clouding agents and whipping agents; additionally, they have applications in the areas of edible films, encapsulating flavors and crystallization inhibition. Besides, hydrocolloids are currently being found to have many increasing applications in the health realm: they provide low-calorie dietary fiber, among many other uses. This review focuses on the trends and progress in the exploration of hydrocolloids to fit the demands for different food products, gives an encyclopedic description of their applications in the food industry as ingredients, food additives and health promoters. Since the use of hydrocolloids is on the rise in many fields, this review that covers both functionality and nutrition of hydrocolloids in foods is both timely and of great interest.
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•The definition of hydrocolloids was put forward.•The comprehensive classification of hydrocolloids was proposed.•The functional properties of hydrocolloids were summarized.•The nutritional effects of hydrocolloids were listed.
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