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Host-based antivirals could offer broad-spectrum therapeutics and prophylactics against the constantly-mutating viruses including the currently-ravaging coronavirus, yet must target cellular vulnerabilities of viruses without grossly endangering the host. Here we show that the master lipid regulator SREBP1 couples the phospholipid scramblase TMEM41B to constitute a host “metabolism-to-manufacture” cascade that maximizes membrane supplies to support coronaviral genome replication, harboring biosynthetic enzymes including Lipin1 as druggable viral-specific-essential (VSE) host genes. Moreover, pharmacological inhibition of Lipin1, by a moonlight function of the widely-prescribed beta-blocker Propranolol, metabolically uncouples the SREBP1-TMEM41B cascade and consequently exhibits broad-spectrum antiviral effects against coronaviruses, Zika virus, and Dengue virus. The data implicate a metabolism-based antiviral strategy that is well tolerated by the host, and a potential broad-spectrum medication against current and future coronavirus diseases.

The anti-penetration performance of the composite armor structures, which are composed of steel, Kevlar composite, and ultra-high molecular weight polyethylene (UHMWPE) composite, were investigated...

Codonopsis Radix (CR) is recorded as the roots of Codonopsis pilosula, C. pilosula var. modesta and Codonopsis tangshen. It is difficult to evaluate the quality of CR because of the existence of many original plants. In this paper, a strategy integrating chromatographic analysis and chemometrics for the quality control of CR is proposed. Systematic analysis of the chemical composition of CR was achieved through high performance liquid chromatography (HPLC) fingerprinting. Based on the HPLC fingerprinting data, chemometrics, including unsupervised principal component analysis (PCA) and supervised orthogonal partial least squares-discrimination analysis (OPLS-DA), were applied to classify all CR samples. Components with variable importance in projection values higher than 1 in the OPLS-DA model were selected as potential chemical markers for distinguishing the origins of CR. Finally, an HPLC method was validated for determining the five characteristic ingredients in the CR samples. HPLC characteristic fingerprints showed 17 common peaks for C. pilosula, 13 for C. pilosula var. modesta, and 9 for C. tangshen, and all of them showed good similarity (>0.9). Additionally, there were 9 common peaks for all CR samples with relatively poor similarity, ranging from 0.607 to 0.970. PCA could differentiate CR from the three origins, except for a partial overlap between C. pilosula and C. pilosula var. Modesta, and the OPLS-DA model achieved excellent classification results. Eight components (peaks 12, 8, lobetyolin, 10, codonopsin І, syringin, 3, and 11) were selected as potential chemical markers. There was a large discrepancy in the contents of the five characteristic ingredients in all samples, with the relative standard deviation ranging from 36.0% (lobetyolin) to 85.9% (atractylenolide Ⅲ). The average contents of the five characteristic ingredients were similar between C. pilosula and C. pilosula var. modesta samples and notably higher than those of C. tangshen samples. Consequently, a rapid, precise, and feasible strategy was established for the discrimination and quality control of CR with different origins.

The dynamic responses of layered polyvinyl chloride (PVC) foam sandwich panels under air blast loads were investigated by employing 3D numerical simulation method. PVC foam of different densities a...

Character-level Chinese dependency parsing has been a concern of several studies that naturally handle word segmentation, POS (Part of Speech) tagging and dependency parsing jointly in an end-to-end way. Previous work mostly concentrates on a transition-based framework for this task because of its easy adaption, which is extremely important when feature representation relies heavily on the decoding strategy, particularly under the traditional statistical setting. Recently, on the one hand, sophisticated deep neural networks and deep contextualized word representations have greatly weakened the dependence between feature representation and decoding. On the other hand, (first-order) graph-based models, especially the biaffine parsers, are straightforward for dependency parsing, and meanwhile they can yield competitive parsing performance. In this paper, we make a comprehensive investigation of the deep graph-based character-level dependency parsing for Chinese. We start from an extension of a standard graph-based biaffine parser, and then exploit Chinese BERT as well as our improved encoders based on transformers to enhance the character-level dependency parsing model. We conduct a series of experiments on the Chinese benchmark datasets, showing the performances of various graph-based character-level models and analyzing the advantages of the character-level dependency parsing under the deep neural setting.

Stepper motors and actuators are among the main constituents of control motion devices. They are complex multibody systems with rather large overall volume due to their multifunctional parts and elaborate technological assembly processes. Miniaturization of individual parts is still posing assembly problems. In this paper, a single-step lithography process to fabricate a micro-stepper engine with an accurate micrometric rotation axis and an overall sub-millimeter size is demonstrated. The device is based on the frictional contacts and chiral metamaterials to get rid of the dependence on the accuracy of parts. The functional aspects of fabricated samples are discussed for many rotation cycles and for different frictional surfaces.

In this article, the design of the hourglass truss sandwich structure is improved by optimizing the number of layers to enhance the compressive strength of both the core and the face sheet and then its mechanical performance. The hourglass truss structures characterized by three different numbers of layers are manufactured using an interlocking and vacuum brazing method. The effect of the layer number of the hourglass core panels on their out-of-plane compression and in-plane compression performance is investigated, and the results from calculations and experiments are in reasonable agreement. The results show that as the layer number of the hourglass core increases, the out-of-plane compressive strengths show little change, but their energy absorption properties are effectively increased. The in-plane compressive failure mechanism maps are constructed, and the specimens are designed to examine the local elastic and inelastic buckling failure modes of the face sheets. The results suggest that as the number of layers of the hourglass core increases, its maximum in-plane compressive load increases. The maximum in-plane compressive loads of the two-layer hourglass truss panels are 57%–70% higher than those of the single-layer panels. It can also be concluded that the out-of-plane and in-plane compression mechanical properties of the multilayer hourglass truss outperform those of the pyramidal truss. Furthermore, the number of layers of the hourglass core is optimized in consideration of both mechanical properties and fabrication cost.

To explore desirable structures with both higher fundamental frequency and better vibration suppression, we designed and fabricated carbon fiber composite bi-directional corrugated sandwich cylindr...

A new type of composite armor, which is composed of the front steel plate, medium dual-layer piecewise ceramic tiles separated by steel grid and the Kevlar back plate, was designed based on the bio...

Lightweight and high-strength sandwich structures with advanced materials are essential for the sustainable development of future industrial development. This paper focuses on investigating the fabrication technology and compression properties of the three-dimensional sandwich structure with lattice cores fabricated by using the continuous carbon fiber reinforced thermoplastic polyether ether ketone (CCF/PEEK). A novel fabrication technology for continuous carbon fiber reinforced thermoplastic polyether ether ketone lattice core is proposed utilizing the unique characteristic of repeated thermoforming of continuous carbon fiber reinforced thermoplastic polyether ether ketone. A mould was designed and then the continuous carbon fiber reinforced thermoplastic polyether ether ketone lattice cores were fabricated. Typical adhesive technology is selected to connect facesheets and lattice cores. The out-of-plane compression behaviors of continuous carbon fiber reinforced thermoplastic polyether ether ketone sandwich structures with lattice cores were investigated by experiment and simulation. Compared with the experimental results, the reliability and correctness of the simulation model were verified. By dint of the simulation model, the effect of stacking sequence of the lattice cores on the structural compression properties was investigated, and the correctness of lattice cores adopted [Formula: see text] stacking sequence in this paper was proved. The continuous carbon fiber reinforced thermoplastic polyether ether ketone lattice sandwich structures exhibit the competitive compression strength with other thermoplastic sandwich structures and surpasses some metal foams at a range of densities.

This paper experimentally and numerically investigates the free vibration, quasi-static compressive and split Hopkinson pressure bar impact responses of hybrid composite pyramidal truss sandwich panels. Such sandwich panels made of carbon fibre composite face sheets and aluminium alloy pyramidal truss cores are fabricated using an interlocking and adhesive bonding approach. Modal tests and quasi-static compression tests are conducted. A good consistency for natural frequencies, modal shapes and static stress–strain curves of the specimen with the same specification is obtained, which ensures the good repeatability of the present specimens. Considering the effect of strain rate, a series of split Hopkinson pressure bar tests combined with numerical simulations is carried out to investigate their dynamic compression responses. A good agreement between simulation results and experimental data is observed, which shows that the adopted split Hopkinson pressure bar testing device and the modified Johnson-Cook model are reasonable and reliable. Results show that the dynamic compression modulus and strength of specimen are strongly influenced by the relative density of the truss cores and much higher than the corresponding static compression modulus and strength. Furthermore, it is also revealed that all the specimens have excellent energy absorption performance, which may have greatly advantage in shock isolation application.

The global poultry industry has grown to the extent that the number of chickens now well exceeds the number of humans on Earth.

Noise reduction and other manipulation of sound waves has been a major concern in science and engineering. Here, we propose a ventilated soundproof acoustic metamaterial consisting of resonant cavities arranged around a central air passage. This metamaterial can accomplish strong sound insulation performance. The transmission loss is larger than 30 dB within a wide frequency range (625–1695 Hz) due to the prohibited band. More intriguingly, we discover that rotating the opening, somewhat like an acoustic switch, can directly control the sound transmission of the deaf band. This is particularly useful for opening a narrow but high transmission window at the frequency of interest, which provides a new degree of freedom for sound control. Through band structure analysis and effective parameter calculation, we discover the sound insulation mechanism of the ventilated metamaterial and reveal the underlying mechanism of the switchable narrow-band sound transmission. Beyond the 1D study, the proposed acoustic metamaterial is expanded to a 3D soundproof metacage. We find that the sound insulation performance and switchable sound transmission phenomena are still retained for the metacage. The results reported here may inspire more exploration of sound barriers and multifunctional applications, such as innovative building facades for noise reduction and logic components for acoustic circuits.