Here stretchable, self‐healable, and transparent gas sensors based on salt‐infiltrated hydrogels for high‐performance NO2 sensing in both anaerobic environment and air at room temperature, are ...reported. The salt‐infiltrated hydrogel displays high sensitivity to NO2 (119.9%/ppm), short response and recovery time (29.8 and 41.0 s, respectively), good linearity, low theoretical limit of detection (LOD) of 86 ppt, high selectivity, stability, and conductivity. A new gas sensing mechanism based on redox reactions occurring at the electrode–hydrogel interface is proposed to understand the sensing behaviors. The gas sensing performance of hydrogel is greatly improved by incorporating calcium chloride (CaCl2) in the hydrogel via a facile salt‐infiltration strategy, leading to a higher sensitivity (2.32 times) and much lower LOD (0.06 times). Notably, both the gas sensing ability, conductivity, and mechanical deformability of hydrogels are readily self‐healable after cutting off and reconnection. Such large deformations as 100% strain do not deprive the gas sensing capability, but rather shorten the response and recovery time significantly. The CaCl2‐infiltrated hydrogel shows excellent selectivity of NO2, with good immunity to the interference gases. These results indicate that the salt‐infiltrated hydrogel has great potential for wearable electronics equipped with gas sensing capability in both anaerobic and aerobic environments.
An intrinsically stretchable, self‐healing, transparent, and ion‐conductive hydrogel is utilized to fabricate NO2 gas sensors. The sensing mechanism reveals that the redox reaction of NO2 at the electrode–hydrogel interface induces current variation. The sensor exhibits high sensitivity (119.9%/ppm), ultralow limit of detection (86 ppt), good selectivity. Meanwhile, it can operate in both anaerobic and aerobic environments at room temperature.
Rearrangement reactions have attracted considerable interest over the past decades due to their high bond-forming efficiency and atom economy in the construction of complex organic architectures. In ...contrast to the well-established 3,3-rearrangement, 1,3 O-to-C rearrangement has been far less vigorously investigated, and stereospecific 1,3-rearrangement is extremely rare. Here, we report a metal-free intramolecular hydroalkoxylation/1,3-rearrangement, leading to the practical and atom-economical assembly of various valuable medium-sized lactams with wide substrate scope and excellent diastereoselectivity. Moreover, such an asymmetric cascade cyclization has also been realized by chiral Brønsted acid-catalyzed kinetic resolution. In addition, biological tests reveal that some of these medium-sized lactams displayed their bioactivity as antitumor agents against melanoma cells, esophageal cancer cells and breast cancer cells. A mechanistic rationale for the reaction is further supported by control experiments and theoretical calculations.
GetOrganelle is a state-of-the-art toolkit to accurately assemble organelle genomes from whole genome sequencing data. It recruits organelle-associated reads using a modified "baiting and iterative ...mapping" approach, conducts de novo assembly, filters and disentangles the assembly graph, and produces all possible configurations of circular organelle genomes. For 50 published plant datasets, we are able to reassemble the circular plastomes from 47 datasets using GetOrganelle. GetOrganelle assemblies are more accurate than published and/or NOVOPlasty-reassembled plastomes as assessed by mapping. We also assemble complete mitochondrial genomes using GetOrganelle. GetOrganelle is freely released under a GPL-3 license ( https://github.com/Kinggerm/GetOrganelle ).
Rogue wave patterns in the nonlinear Schrödinger equation are analytically studied. It is shown that when an internal parameter in the rogue waves (which controls the shape and phase of initial weak ...perturbations to the uniform background) is large, these waves would exhibit clear geometric structures, which are formed by Peregrine waves in shapes such as triangle, pentagon, heptagon and nonagon, with a possible lower-order rogue wave at its center. These rogue patterns are analytically determined by the root structures of the Yablonskii–Vorob’ev polynomial hierarchy, and their orientations are controlled by the phase of the large parameter. It is also shown that when multiple internal parameters in the rogue waves are large but satisfy certain constraints, similar rogue patterns would still hold. Comparison between true rogue patterns and our analytical predictions shows excellent agreement.
•Rogue wave patterns in the nonlinear Schrodinger equation are analytically determined.•A deep connection between rogue patterns and Yablonskii–Vorob’ev polynomials is found.•Analytical predictions of rogue patterns match true ones perfectly.
Conspectus Supramolecular self-assembly, which creates the ordered structures as a result of spontaneous organization of building blocks driven by noncovalent interactions (NCIs), is ubiquitous in ...nature. Recently, it has become increasingly clear that nature often builds up complex structures by employing a hierarchical self-assembly (HSA) strategy, in which the components are brought together in a stepwise process via multiple NCIs. Inspired by the dedicated biological structures in nature, HSA has been widely explored to construct well-defined assemblies with increasing complexity. The employment of direct metal–ligand bonds to drive the formation of discrete metallosupramolecular architectures has proven to be a highly efficient strategy to prepare structurally diverse architectures like two-dimensional (2-D) polygons and three-dimensional (3-D) polyhedra with well-defined shapes, sizes, and geometries. Such well-defined organometallic assemblies provide an ideal platform for designing novel artificial supramolecular systems with the increasing complexity though HSA. The presence of a well-defined organometallic scaffold brings an additional dimension to the final nanoscale structures. Moreover, the multilevel dynamic nature of hierarchical self-assemblies brings more structural and functional possibilities of resultant supramolecular systems. This Account will focus on our recent advance on construction of stimuli-responsive functional materials through HSA involving coordination interactions. In our study, a series of functionalized metallacycles were first constructed through coordination-driven self-assembly (CDSA). Then, the secondary noncovalent interaction sites were integrated within the functionalized metallacycle system via either preassembly or postassembly approach. Different segments, such as alkyl chains, dendrimers, cholesteryl moiety, covalent macrocycles, and even polymeric fragments, which could provide hydrophobic and hydrophilic interactions, van der Waals forces, hydrogen bonding, CH−π and π–π interactions, and host–guest interactions, have been utilized to provide the secondary NCIs. Further self-assembly of functionalized metallacycles gives rise to the formation of complex higher-order structures driven by other NCIs by taking advantages of orthogonal property of coordination bonds with other NCIs. By changing the type of additional NCIs embodied in building blocks, different supramolecular architectures, such as the ordered nanostructures, supramolecular polymers and gels, fluorescent materials and sensors, have been successfully prepared with the tailored chemical and physical properties. In particular, the dynamic nature of coordination bonds as well as other NCIs endows final assemblies with stimuli-responsive functions. Collectively, our studies suggest that combining coordination and other NCIs in a well-defined and precise manner is a highly efficient strategy to achieve the complex architectures and functional materials. Therefore, it is very promising to develop the desired functional materials with high precision and fidelity by employing HSA involving coordination interactions.
Water disinfection can result in the unintended formation of halogenated disinfection byproducts (DBPs), which have been the subject of intensive investigation over the past 40 years. Robust methods ...for evaluating and characterizing the formation of halogenated DBPs are prerequisites for ultimately controlling the formation of DBPs and ensuring quality and safe disinfected water. Only a fraction of the total organic halogen (TOX) formed during disinfection has been chemically identified or even well characterized by the classical (derivatization-)gas chromatography/mass spectrometry (GC/MS) method. Such a method may not be amenable to the detection of polar halogenated DBPs, which constitute a major portion of the TOX that is still unaccounted for. Accordingly, a novel precursor ion scan (PIS) method using (liquid chromatography/) electrospray ionization-triple quadrupole mass spectrometry was developed for the rapid selective detection of all polar halogenated DBPs—no matter whether the DBPs are known or unknown—in water. This article reviews recent literature on the application of the PIS method for evaluating the occurrence, formation and control of polar halogenated DBPs in disinfected waters. The challenges in developing the PIS method were briefly summarized. Application of the powerful method pinpointed >150 previously unknown DBPs and revealed the formation, speciation and transformation of halogenated DBPs in disinfected drinking water, wastewater effluents, and swimming pool water. For the same source water, positive correlations were found between the total ion intensity (TII) levels in the PIS spectra of m/z 35/79/126.9 and the total organic chlorine/bromine/iodine levels in the disinfected water sample, and a disinfected sample with a higher TII level generally showed a higher toxic potency. Accordingly, the TII value can be used as a surrogate to comparatively reflect the water quality and assess the efficiency of a DBP control approach. To achieve a more comprehensive and systematic understanding of the DBP compositions in different waters and thus better control the DBP formation and reduce their overall toxicity, topics for future work were discussed.
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•Application of a powerful precursor ion scan method was comprehensively reviewed.•Numerous polar halogenated DBPs were selectively detected by the PIS method.•Dozens of new halogenated DBPs were identified with the aid of the PIS method.•The TII value in a PIS spectrum was used to indicate the overall DBP formation.•Areas for further development and application of the PIS method were indicated.
Microbial biochemicals have been indicated as the primary stimulators of innate immunity, the first line of the body's defence against infections. However, the influence of topological features on a ...microbe's surface on immune responses remains largely unknown. Here we demonstrate the ability of TiO
microparticles decorated with nanospikes (spiky particles) to activate and amplify the immune response in vitro and in vivo. The nanospikes exert mechanical stress on the cells, which results in potassium efflux and inflammasome activation in macrophages and dendritic cells during phagocytosis. The spiky particles augment antigen-specific humoral and cellular immune responses in the presence of monophosphoryl lipid A and elicit protective immunity against tumour growth and influenza viral infection. The study offers insights into how surface physical cues can tune the activation of innate immunity and provides a basis for engineering particles with increased immunogenicity and adjuvanticity.
As one of the main forms and intermediate carriers of energy, it is impressive to expand the application scope of heat energy, thereby boosting innovations in heat harvesting, conversion, storage, ...regulation, and utilization associated with the relevant techniques. Phase change materials (PCMs), as a state‐of‐the‐art latent heat storage technique, have garnered increasing interest in heat‐related applications over the past decades, and abundant high‐performance PCMs with excellent shape stability and salient thermal conductivity have been developed. This review focuses on the issues concerning organic PCMs from the perspectives of flexible, multifunctional, and smart phase change composites, along with emerging applications and processing technologies, which are expected to offer possible guidance for the exploration of next‐generation advanced functional phase change composites.
Next‐generation advanced functional phase change composites are analyzed from the perspectives of myriad phase change materials, promising applications, and mass‐manufactured processing technologies to boost their rapid implementation.
•A self-learning GA (SLGA) which combines both SARSA and Q-learning with GA is first proposed to solve FJSP.•The combined model of SLGA is constructed according to the features of GA and RL.•SARSA ...algorithm and Q-learning algorithm of RL are combined, which constitute the main part of learning module in SLGA.•The components of RL are designed, including the state of GA environment, action of parameters adjustment, and reward method.•The mixedstrategy of SARSA algorithm and Q-learning algorithm improve the efficiency of SLGA for FJSP.
As an important branch of production scheduling, flexible job-shop scheduling problem (FJSP) is difficult to solve and is proven to be NP-hard. Many intelligent algorithms have been proposed to solve FJSP, but their key parameters cannot be dynamically adjusted effectively during the calculation process, which causes the solution efficiency and quality not being able to meet the production requirements. Therefore, a self-learning genetic algorithm (SLGA) is proposed in this paper, in which genetic algorithm (GA) is adopted as the basic optimization method and its key parameters are intelligently adjusted based on reinforcement learning (RL). Firstly, the self-learning model is analyzed and constructed in SLGA, SARSA algorithm and Q-Learning algorithm are applied as the learning methods at initial and later stages of optimization, respectively, and the conversion condition is designed. Secondly, the state determination method and reward method are designed for RL in GA environment. Finally, the learning effect and performance of SLGA in solving FJSP are compared with other algorithms using two groups of benchmark data instances with different scales. Experiment results show that the proposed SLGA significantly outperforms its competitors in solving FJSP.
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