During an outbreak of respiratory diseases including atypical pneumonia in Wuhan, a previously unknown β‐coronavirus was detected in patients. The newly discovered coronavirus is similar to some ...β‐coronaviruses found in bats but different from previously known SARS‐CoV and MERS‐CoV. High sequence identities and similarities between 2019‐nCoV and SARS‐CoV were found. In this study, we searched the homologous templates of all nonstructural and structural proteins of 2019‐nCoV. Among the nonstructural proteins, the leader protein (nsp1), the papain‐like protease (nsp3), the nsp4, the 3C‐like protease (nsp5), the nsp7, the nsp8, the nsp9, the nsp10, the RNA‐directed RNA polymerase (nsp12), the helicase (nsp13), the guanine‐N7 methyltransferase (nsp14), the uridylate‐specific endoribonuclease (nsp15), the 2'‐O‐methyltransferase (nsp16), and the ORF7a protein could be built on the basis of homology templates. Among the structural proteins, the spike protein (S‐protein), the envelope protein (E‐protein), and the nucleocapsid protein (N‐protein) can be constructed based on the crystal structures of the proteins from SARS‐CoV. It is known that PL‐Pro, 3CL‐Pro, and RdRp are important targets for design antiviral drugs against 2019‐nCoV. And S protein is a critical target candidate for inhibitor screening or vaccine design against 2019‐nCoV because coronavirus replication is initiated by the binding of S protein to cell surface receptors. It is believed that these proteins should be useful for further structure‐based virtual screening and related computer‐aided drug development and vaccine design.
Highlights
High sequence identities between 2019‐nCoV and SARS‐CoV were found. Homology templates of all structural proteins of 2019‐nCoV were identified. Homology templates of all nonstructural proteins of 2019‐nCoV were identified.
Next‐generation energy storage devices should be soft, stretchable, and self‐healable. Previously reported self‐healable batteries mostly possess limited stretchability and rely on healable ...electrodes or electrolytes rather than achieving full‐device self‐healability. Herein, an all‐component self‐bonding strategy is reported to obtain an all‐eutectogel soft battery (AESB) that simultaneously achieves full‐cell autonomous self‐healability and omnidirectional intrinsic stretchability (>1000% areal strain) over a broad temperature range (−20~60 °C). Without requiring any external stimulus, the five‐layered soft battery can efficiently recover both its mechanical and electrochemical performance at full‐cell level. The developed AESB can be easily configured into various 3D architectures with highly interfacial compatible eutectogel electrodes, electrolyte, and substrate, presenting an excellent opportunity for the development of embodied energy technologies. The present work provides a general and user‐friendly soft electronic material platform for fabricating a variety of intrinsic self‐healing stretchable multi‐layered electronics, which are promising beyond the field of energy storage, such as displays, sensors, circuits, and soft robots.
Most reported self‐healable batteries possess limited stretchability and unable to achieve full‐device self‐healability. Herein, an all‐component self‐bonding strategy is presented to obtain an all‐eutectogel soft battery (AESB) that simultaneously achieves full‐cell autonomous self‐healability and omnidirectional intrinsic stretchability (>1000% areal strain) even at –20 °C. The present work provides a general soft electronic material platform for fabricating next‐generation self‐healing stretchable electronics.
A series of solid supramolecules based on acrylamide–phenylpyridium copolymers with various substituent groups (P−R: R=−CN, −CO2Et, −Me, −CF3) and cucurbit7uril (CB7) are constructed to exhibit ...tunable second‐level (from 0.9 s to 2.2 s) room‐temperature phosphorescence (RTP) in the amorphous state. Compared with other solid supramolecules P−R/CB7 (R=−CN, −CO2Et, −Me), P−CF3/CB7 displays the longest lifetime (2.2 s), which is probably attributed to the fluorophilic interaction of cucurbiturils leading to a uncommon host–guest interaction between 4‐phenylpyridium with −CF3 and CB7. Furthermore, the RTP solid supramolecular assembly (donors) can further react with organic dyes Eosin Y or SR101 (acceptors) to form ternary supramolecular systems featuring ultralong phosphorescence energy transfer (PpET) and visible delayed fluorescence (yellow for EY at 568 nm and red for SR101 at 620 nm). Significantly, the ultralong multicolor PpET supramolecular assembly can be further applied in fields of anti‐counterfeiting and information encryption and painting.
Solid supramolecules based on acrylamide–phenylpyridium copolymers with various substituent groups and cucurbit7uril not only exhibit tunable ultralong phosphorescence with lifetimes varying from 0.9 s to 2.2 s, but also co‐assemble with organic dyes Eosin Y or SR101 to display high‐performance phosphorescence energy transfer with multicolor delayed fluorescence properties.
Abstract
The dynamic regulation of supramolecular chirality in non-equilibrium systems can provide valuable insights into molecular self-assembly in living systems. Herein, we demonstrate the use of ...chemical fuels for regulating self-assembly pathway, which thereby controls the supramolecular chirality of assembly in non-equilibrium systems. Depending on the nature of different fuel acids, the system shows pathway-dependent non-equilibrium self-assembly, resulting in either dynamic self-assembly with transient supramolecular chirality or kinetically trapped self-assembly with inverse supramolecular chirality. More importantly, successive conducting of chemical-fueled process and thermal annealing process allows for the sequential programmability of the supramolecular chirality between four different chiral hydrogels, affording a new example of a multistate supramolecular chiroptical switch that can be recycled multiple times. The current finding sheds new light on the design of future supramolecular chiral materials, offering access to alternative self-assembly pathways and kinetically controlled non-equilibrium states.
Persistent organic pollutants (POPs) exist widely in the environment and place significant impact on human health by bioaccumulation. Efficient recognition of POPs and their removal are highly ...challenging tasks because their specific structures interact often very weakly with the capture materials. Herein, a molecular nanocage (1) is studied as an efficient sensing and sorbent material for POPs, which is demonstrated by a representative and stable perfluorooctane sulfonate (PFOS) substrate containing a hydrophilic sulfonic group and a hydrophobic fluoroalkyl chain. A highly sensitive and unusual turn-on fluorescence response within 10 s and a 97% total removal of PFOS from water in 20 min have been achieved owing to the strong host–guest interactions between 1 and PFOS. The binding constant of 1 to PFOS is 2 orders of magnitude higher than state-of-the-art adsorbents for PFOS and thus represents a new benchmark material for the recognition and removal of PFOS. The host–guest interaction has been elucidated by solid-state NMR spectroscopy and single-crystal X-ray diffraction, which provide key insights at a molecular level for the design of new advanced sensing/sorbent materials for POPs.
First‐principles density‐functional calculations are performed to investigate the electronic structure and magnetic properties of d0 magnetic short‐period heterostructures (MC)1/(SiC)1 (0001) (M = Ca ...and K) in wurtzite structure. We found that they are thermodynamically and mechanically stable by the calculations and analyses of formation energies, cohesive energies, and elastic stiffness constants. Moreover, the dynamic stabilities of them were checked from ab initio molecular dynamics. After adding onsite Coulomb repulsion, both (CaC)1/(SiC)1 and (KC)1/(SiC)1 short‐period heterostructures are predicted to be magnetic semiconductors. The two carbons per cell couple ferromagnetically and ferrimagnetically for (CaC)1/(SiC)1 and (KC)1/(SiC)1 short‐period heterostructures, respectively.
First-principles calculations were used to investigate several inverse Ti2CoSi-based compounds. Our results indicate that Ti2CoSi could transform from a spin-gapless semiconductor to a half metal if ...a quarter of the Co atoms are replaced by Ti. Ti2.25Co0.75Si would keep stable half-metallic properties in a large range of lattice parameter under the effect of hydrostatic strain, and would become a gapless half metal under the effect of tetragonal distortion. Furthermore, we substituted B, Al, Ga, P, As, and Sb for Si in the Ti2.25Co0.75Si compound. Our results demonstrate that Ti2.25Co0.75Si0.5B0.5, Ti2.25Co0.75Si0.5Al0.5, and Ti2.25Co0.75Si0.5Ga0.5 are half-metallic ferromagnetic materials, and Ti2.25Co0.75Si0.5P0.5, Ti2.25Co0.75Si0.5As0.5, and Ti2.25Co0.75Si0.5Sb0.5 are spin-gapless semiconducting materials. The introduced impurity atoms may adjust the valence electron configuration, change the charge concentration, and shift the location of the Fermi level.
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•Electronic, magnetic and optical properties of antimonene were investigated.•The Cr-doped antimonene exhibits half-metallicity under strain of 6%.•The band gap closing can be ...achieved under strains range from −4% to −6%.•The absorption efficiency of visible light can be increased.
Our work develops a novel pathway for controllable and tunable spintronics and optoelectronics devices. The biaxial strain and doping functions on electronic structure, magnetic and optical properties were explored with the method of density functional theory (DFT). Results show that the Cr-doped antimonene is a narrow indirect band-gap semiconductor (0.44 eV), and the valence band maximum (VBM) changes from K to Г point due to spin-orbit coupling (SOC) interaction. Hence, there exists a remarkable spin splitting near EF caused by the coexistence of strong p-d hybridization and SOC effect. The total net magnetic moment is 3.00 µB in Cr-doped antimonene system, while the coupling interaction between them is anti-ferromagnetism (AFM) order, which facilitates its use in AFM-based spintronic devices. For the case of coexistence of strain and Cr dopant, the Cr-doped system transforms from magnetic semiconductor to magnetic half-metal material under the biaxial tensile strain of 6%. Most interestingly, the band gap closing can be achieved when biaxial strains range from −4% to −6%, so these systems present metal characteristics. Comparing with the unstrained doping system, the local magnetic moments increase to 4.49 and 5.00 µB at biaxial tensile strains of 6% and 8%, respectively. More importantly, we found that the absorption efficiency of visible light can be increased by Cr incorporation as well as biaxial compression strain applied to the Cr-doped antimonene system.
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•Electronic and magnetic properties of defective antimonene were investigated.•The Fe-doped antimonene can achieve RTFM.•Spin-orbit coupling effects lead to a spin splitting.•The ...defect complex tuned system presents AFM order.
We investigate the electronic and magnetic properties of Fe-doped (FeSb) and defect complex (FeSb + VSb) tuned antimonene systems. Our calculations showed that the method of generalized gradient approximation with on-site Coulomb repulsion (GGA+U) obtained a larger magnetic moment in the two defect systems than that of generalized gradient approximation (GGA). When the spin–orbit couplings (SOC) effects were turned on, the Fe-doped system transforms from a narrow band-gap semiconductor to a semi-metallic material by the scheme of GGA+U. Moreover, the concurrence of strong orbital hybridization (p-d) and spin-orbit interaction lead to a significant spin splitting around the Fermi level. Especially, stable room temperature ferromagnetism (RTFM) is obtained in Fe-doped systems. However, the system presents anti-ferromagnetism (AFM) order when two intrinsic vacancies (VSb) are introduced into the Fe-doped systems, which is not conducive to Fe-doped antimonene materials applied in spintronics devices. Comparing with pure antimonene, the relatively flat impurity band indicates lower carrier mobility in FeSb + VSb system. Hence, in Fe-doped antimonene materials, the intrinsic vacancies should be effectively suppressed in experimental fabrication.
A loop-mediated isothermal amplification (LAMP) assay was employed to develop a simple and efficient system for the detection of squash leaf curl virus (SLCV) in diseased plants of squash (Cucurbita ...pepo) and melon (Cucumis melo). Completion of LAMP assay required 30–60min under isothermal conditions at 65°C by employing a set of four primers targeting SLCV. Although the sensitivity of the LAMP assay and the polymerase chain reaction (PCR) assay was comparable at high virus concentrations, the LAMP assay was by a 10-fold dilution factor more sensitive than the PCR assay for the detection of SLCV in diseased plants. No reaction was detected in the tissues of healthy plants by either the LAMP or the PCR. The LAMP products can be visualized by staining directly in the tube with SYBR® Safe DNA gel stain dye. The sensitivity of the SYBR® Safe DNA gel stain is similar to analysis by gel electrophoresis. Although both the LAMP and the PCR methods were capable of detecting SLCV in infected tissues of squash and melon, the LAMP method would be more useful than the PCR method for detection of SLCV infection in cucurbitaceous plants because it is more rapid, simple, accurate and sensitive.
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