Search

The PDI-EH molecule was synthesized and integrated into ternary OSCs to obtain miscibility-driven morphology optimization. The relationship between the optimized morphology and charge carrier dynamics was explored by PiFM and TP-AFM characterization.

Circular RNAs (circRNAs) play important roles in a variety of physiological and pathological processes. Researches demonstrated that circRNAs provided novel strategies for the prevention and treatment of IS. However, the biological function of hsa_circ_0045932 (circUSP36) has not been revealed yet. Here, we explored the effect of circUSP36 on IS and its mechanism. In the present study, we found that circUSP36 expression was significantly decreased in the peripheral blood of IS patients and was negatively correlated with the severity, infarct volume and poor prognosis of IS. Functionally, circUSP36 silencing inhibited cellular activity and proliferation and promoted apoptosis after oxygen-glucose deprivation/reperfusion (OGD/R) treatment, while circUSP36 overexpression reversed these cellular phenotypes in vitro. Adeno-associated virus (AAV)-mediated overexpression of circUSP36 attenuates brain injury and neurological deficit and promotes motor function recovery of transient middle cerebral artery occlusion (tMCAO) mice. Subsequently, the RNA antisense purification (RAP) and luciferase reporter assay confirmed that circUSP36 acts as a sponge to adsorb miR-139-3p, and miR-139-3p could bind and inhibit SMAD3 expression. Further rescue experiments showed that both miR-139-3p overexpression and SMAD3 silencing could abolish the antiapoptotic effect of circUSP36. In summary, we reveal for the first time that circUSP36 attenuates ischemic stroke injury through the miR-139-3p/SMAD3/Bcl2 signal axis, which make circUSP36 a potential therapeutic target for IS.

SummaryDevelopment of vaccines and therapeutics that are broadly effective against known and emergent coronaviruses is an urgent priority. Current strategies for developing pan-coronavirus countermeasures have largely focused on the receptor binding domain (RBD) and S2 regions of the coronavirus Spike protein; it has been unclear whether the N-terminal domain (NTD) is a viable target for universal vaccines and broadly neutralizing antibodies (Abs). Additionally, many RBD-targeting Abs have proven susceptible to viral escape. We screened the circulating B cell repertoires of COVID-19 survivors and vaccinees using multiplexed panels of uniquely barcoded antigens in a high-throughput single cell workflow to isolate over 9,000 SARS-CoV-2-specific monoclonal Abs (mAbs), providing an expansive view of the SARS-CoV-2-specific Ab repertoire. We observed many instances of clonal coalescence between individuals, suggesting that Ab responses frequently converge independently on similar genetic solutions. Among the recovered antibodies was TXG-0078, a public neutralizing mAb that binds the NTD supersite region of the coronavirus Spike protein and recognizes a diverse collection of alpha- and beta-coronaviruses. TXG-0078 achieves its exceptional binding breadth while utilizing the same VH1-24 variable gene signature and heavy chain-dominant binding pattern seen in other NTD supersite-specific neutralizing Abs with much narrower specificity. We also report the discovery of CC24.2, a pan-sarbecovirus neutralizing mAb that targets a novel RBD epitope and shows similar neutralization potency against all tested SARS-CoV-2 variants, including BQ.1.1 and XBB.1.5. A cocktail of TXG-0078 and CC24.2 provides protection againstin vivochallenge with SARS-CoV-2, suggesting potential future use in variant-resistant therapeutic Ab cocktails and as templates for pan-coronavirus vaccine design.

Sufficient sunlight absorption and exciton generation are critical for developing efficient nonfullerene organic solar cells (OSCs). In this work, polyelectrolyte polystyrenesulfonate (PSS)-coated plasmonic gold nanorods (GNRs@PSS) were incorporated, for the first time, into the inverted nonfullerene OSCs as rear interfacial modifiers to improve sunlight absorption and charge generation via the near-field plasmonic and backscattering effects. The plasmonic GNRs effectively improved the sunlight absorption and enhanced the charge generation. Meanwhile, the negatively charged PSS shell ensured the uniform dispersion of the GNRs on the surface of the photoactive layer, optimized the interfacial contact, and further promoted the hole transport to the electrode. These concerted synergistic effects augmented the efficiency (10.11%) by nearly 20% relative to the control device (8.47%). Remarkably, the ultrathin (∼2.2 nm) organic layer on the surface of GNRs was closely examined by acquiring the carbon contrast image through energy-filtered transmission electron microscopy (EF-TEM), which clearly confirmed the coating uniformity from the side to end-cap of GNRs. The surface plasmon resonance (SPR) effect of the GNRs@PSS on the surface of the photoactive layer was unprecedentedly mapped by photoinduced force microscopy (PiFM) under the illumination of a tunable wavelength supercontinuum laser mimicking sunlight. Furthermore, investigations into the effect of size, surface coverage, and incorporation location of GNRs@PSS on the performance of OSCs revealed that the appropriate design and incorporation of the plasmonic nanostructures are crucial, otherwise the performance can be decreased, as evidenced in the case of front interface integration.

Handgrip force prediction is widely used in the rehabilitation of the arm and prosthetic control. To investigate the effects of different measurement positions and feature parameters on the results of handgrip force prediction, a model based on electrical impedance myography (EIM) and long short-term memory (LSTM) networks was proposed to compare and determine a better scheme for handgrip force prediction. We conducted the signal acquisition experiments of impedance and handgrip force on the anterior forearm muscles and brachioradialis muscle. Afterwards, three evaluationmetrics were introduced to compare the prediction results of various models, and the variability between models was analyzed using paired sample t-tests. The results showed that the model of handgrip force prediction based on anterior forearm muscles exhibited better performance in predicting. The evaluation metrics of R^2, explained variance score (EVS) and normalized mean square error (NMSE) for the model fusing the feature parameters resistance (R) and reactance (X) were 0.9023, 0.9173 and 0.0114, respectively. Therefore, the feature parameters fusing R and X are the optimal input for the handgrip force prediction model. The anterior forearm muscles are the preferred position for impedance measurement over the brachioradialis muscle. This paper validated the feasibility of EIM for handgrip force prediction and provided a new reference and implementation scheme for muscle rehabilitation training and prosthetic control.

Plasmonic polymeric nanoassemblies offer valuable opportunities in photoconversion applications. Localized surface plasmon mechanisms behind such nanoassemblies govern their functionalities under light illumination. However, an in-depth investigation at the single nanoparticle (NP) level is still challenging, especially when the buried interface is involved, due to the availability of suitable techniques. Here, we synthesized an anisotropic heterodimer composed of a self-assembled polymer vesicle (THPG) capped with a single gold NP, enabling an 8-fold enhancement in hydrogen generation compared to the nonplasmonic THPG vesicle. We explored the anisotropic heterodimer at the single particle level by employing advanced transmission electron microscopes, including one equipped with a femtosecond pulsed laser, which allows us to visualize the polarization- and frequency-dependent distribution of the enhanced electric near fields at the vicinity of Au cap and Au–polymer interface. These elaborated fundamental findings may guide designing new hybrid nanostructures tailored for plasmon-related applications.

Avian-to-human transmission of highly pathogenic avian influenza viruses (HPAIV) and their subsequent adaptation to humans are of great concern to public health. Surveillance and early warning of AIVs with the potential to infect humans and pandemic potential is crucial. In this study, we determined whether adaptive evolution occurred in human-isolated H5 viruses. We evaluated all available genomes of H5N1 and H5N6 avian influenza A virus. Firstly, we systematically identified several new mutations in H5 AIV that might be associated with human adaptation using a combination of novel comparative phylogenetic methods and structural analysis. Some changes are the result of parallel evolution, further demonstrating their importance. In total, we identified 102 adaptive evolution sites in eight genes. Some residues had been previously identified, such as 227 in HA and 627 in PB2, while others have not been reported so far. Ten sites from four genes evolved in parallel but no obvious positive selection was detected. Our study suggests that during infection of humans, H5 viruses evolved to adapt to their new host environment and that the sites of adaptive/parallel evolution might play a role in crossing the species barrier and are the response to new selection pressure. The results provide insight to implement early detection systems for transitional stages in H5 AIV evolution before its potential adaptation for humans. Author summary line The prerequisite of surveillance and early warning of avian influenza viruses with the potential to infect humans depends on the identification of human-adaptation related mutations. In this study, we used a novel approach combining both phylogenetic and structural analysis to identify possible human-adaptation related mutations in H5 AIVs. Previous studies reported human-adaptation related mutations and some novel mutations exhibiting parallel evolution. Our result provides new insights into how AIVs adapt to humans by point mutations.

Previous studies on intentional and incidental face memory have investigated the effects of emotional facial expression on facial recognition itself. However, it is still uncertain whether facial expression influences later recognition of other emotional stimuli, such as emotional scenes. To address this issue, participants during the encoding phase were presented with emotional scenes together with facial expressions. The emotion of the scenes was either congruent or incongruent with that of the facial expression. In order to increase the attention towards faces/facial expressions, the task was related to faces rather than scenes, for example, the participants were asked either to memorize the facial identities (intentional face learning, Experiment 1) or to identify the gender of the faces (incidental face learning, Experiment 2). Subsequently, the participants were asked to perform an unexpected old/new recognition task regarding the scene pictures. In general, the results showed that recognition of threat-related scenes was enhanced by a preceding emotionally incongruent facial expression irrespective of intentional or incidental face learning. The findings indicate that facial expression influences recognition of contextual threat-related scenes.

Stroke was the third leading cause of global disability-adjusted life years and its treatment drugs were limited. Researchers still need to find reliable diagnostic biomarkers and therapeutic targets. This study aimed to explore hub genes associated with ischemic stroke (IS) through bioinformatics analysis and identify its potential diagnostic biomarkers and therapeutic targets. The microarray data sets of GSE58294 and GSE16561 related to IS were downloaded from the Gene Expression Omnibus (GEO) database. Weighted co-expression network analysis (WGCNA) and differential expression analysis were integrated to find overlapping genes, and then hub genes were screened by Least absolute shrinkage and selection operator (LASSO) regression. NetworkAnalyst database was used to construct the TF-gene network and miRNA-TF regulatory network of the hub genes. DGIdb and CMap databases were used to predict targeted drugs and small molecule compounds. Through the Comprehensive analysis of GSE58294 and GSE16561, 10 hub genes were screened by LASSO regression, namely ARG1, LY96, ABCA1, SLC22A4, CD163, TPM2, SLC25A42, ID3, FAM102A and CD79B. NetworkAnalyst database analysis showed that ABCA1 was the hub gene most regulated by miRNA and TF. TRRUST and NetworkAnalyst databases showed that SP1 (P=0.0246) was a key transcription factor for hub genes. Finally, DGIdb database analysis identified 7 therapeutic drugs targeted with ABCA1 and SLC22A4, and 4 small molecule compounds targeted with ID3 and SLC22A4 were obtained from CMap database. We identified IS-related diagnostic biomarkers and therapeutic drugs, which can provide new insights for the diagnosis and treatment of IS.

Polymer-inorganic hybrid Janus nanoparticles (PI-JNPs) have attracted extensive attention due to their special structures and functions. However, achieving the synergistic enhancement of photochemical activity between polymer and inorganic moieties in PI-JNPs remains challenging. Herein, we report the construction of a novel Janus Au-porphyrin polymersome (J-AuPPS) heterostructure by a facile one-step photocatalytic synthesis. The near-field enhancement (NFE) effect between porphyrin polymersome (PPS) and Au nanoparticles in J-AuPPS is achieved to enhance its near-infrared (NIR) light absorption and electric/thermal field intensity at their interface, which improve the energy transfer and energetic charge carrier generation. Therefore, J-AuPPS shows a higher NIR-activated photothermal conversion efficiency (48.4%) and generates more singlet oxygen compared with non-Janus core-particle Au-PPS nanostructure (28.4%). As a result, J-AuPPS exhibits excellent dual-mode (photothermal/photodynamic) antibacterial and antibiofilm performance and thereby significantly enhances in vivo therapeutic effect on the implant-associated infection rat model. We believe this work will motivate the rational design of advanced hybrid Janus nanoparticles with the desirable NFE effect and further extend their biological applications. This article is protected by copyright. All rights reserved.

Exposure to metals during pregnancy may affect maternal and infant health. However, studies on the combined effects of metals on the telomere length (TL) of newborns are limited. A prospective cohort study was conducted among 1313 mother-newborn pairs in the Guangxi Zhuang Birth Cohort. The concentrations of metals in maternal plasma during the first trimester were measured using inductively coupled plasma-mass spectrometry. We explored the associations between nine plasma metals and newborn TL using generalized linear models (GLMs), principal component analysis (PCA), quantile g-computation (qgcomp), and Bayesian kernel machine regression (BKMR). The GLMs revealed the inverse association between plasma arsenic (percent change, -5.56%; 95% CI: -7.69%, -3.38%) and barium concentrations (-9.84%; 95% CI: -13.81%, -5.68%) and newborn TL. Lead levels were related to significant decreases in newborn TL only in females. The PCA revealed a negative association between the PC3 and newborn TL (-4.52%; 95% CI: -6.34%, -2.68%). In the BKMR, the joint effect of metals was negatively associated with newborn TL. Qgcomp indicated that each one-tertile increase in metal mixture levels was associated with shorter newborn TL (-9.39%; 95% CI: -14.32%, -4.18%). The single and joint effects of multiple metals were more pronounced among pregnant women carrying female fetuses and among pregnant women28 years of age. The finding suggests that prenatal exposure to arsenic, barium, antimony, and lead and mixed metals may shorten newborn TLs. The relationship between metal exposures and newborn TL may exhibit heterogeneities according to infant sex and maternal age.

The circular RNA (circRNA) circLAMA3 is significantly downregulated in bladder cancer tissues and cell lines. However, its function in bladder cancer has not yet been explored, and further research is needed. In this study, functional experiments demonstrated that circLAMA3 significantly inhibited the proliferation, migration, and invasion of bladder cancer cells and inhibited bladder cancer growth

WO3 films are the most widely used electrochromic functional layers. It is known that WO3 films prepared by pure chemical method generally possess novel nanostructures, but the adhesion between WO3 films and substrates is weak. However, WO3 films prepared by pure physical method usually show relatively dense morphology, which limits their electrochromic properties. In order to break through these bottlenecks and further improve their electrochromic properties, this work first prepared nanostructured WO3 powder by chemical method, and then using this powder as the evaporation source, nanostructured WO3 films were fabricated by vacuum thermal evaporation method. Properties of nanostructured WO3 films were systematically compared with those of ordinary WO3 films. It turned out that the nanostructured WO3 film exhibited better cyclic stability and memory effect, and also the optical modulation rate was 14% higher than that of the ordinary WO3 film. More importantly, the nanostructured WO3 film showed better adhesion with the ITO substrates. These results demonstrate that a combination of chemical and physical methods is an effective preparation method to improve the electrochromic properties of WO3 films.

Stroke is the third leading cause of disability-adjusted life years worldwide, and drugs available for its treatment are limited. This study aimed to explore high-confidence candidate genes associated with ischemic stroke (IS) through bioinformatics analysis and identify potential diagnostic biomarkers and gene-drug interactions. Weighted gene coexpression network analysis (WGCNA) and differentially expressed genes (DEGs) were integrated to identify overlapping genes. Then, high-confidence candidate genes were screened by least absolute shrinkage and selection operator (LASSO) regression. Receiver operating characteristic (ROC) curves were used to evaluate the diagnostic value of high-confidence candidate genes as biomarkers for IS. The NetworkAnalyst database was used to construct the TF-gene network and miRNA-TF regulatory network of the high-confidence candidate genes. The DGIdb database was used to identified gene-drug interactions. Through the comprehensive analysis of GSE58294 and GSE16561, 10 high-confidence candidate genes were identified by LASSO regression: ARG1, LY96, ABCA1, SLC22A4, CD163, TPM2, SLC25A42, ID3, FAM102A and CD79B. FAM102A had the highest diagnostic value, and the area under curve (AUC), sensitivity and specificity values were 0.974, 0.919 and 0.936, respectively. The HPA database demonstrated that 10 high-confidence candidate genes were expressed in the brain and blood in normal humans. Finally, DGIdb database analysis identified 8 gene-drug interactions. We identified IS-related diagnostic biomarkers and gene-drug interactions that potentially provide new insights into the diagnosis and treatment of IS.

Background Pseudorabies virus (PRV) causes Aujeszky's disease in pigs and can be transmitted to other mammals, including humans. In the current study, we systematically studied the interspecies transmission and evolutionary history of PRV. Methods We performed comprehensive analysis on the phylodynamics, selection, and structural biology to summarize the phylogenetic and adaptive evolution of PRV based on all available full-length and major glycoprotein sequences. Results PRV can be divided into 2 main clades with frequent interclade and intraclade recombination. Clade 2.2 (variant PRV) is currently the most prevalent genotype worldwide, and most commonly involved in cross-species transmission events (including humans). We also found that the population size of clade 2.2 has increased since 2011, and the effective reproduction number was >1 from 2011 to 2016, indicating that PRV may be still circulating in swine herds and is still a risk in relation with cross-species transmission in China. Of note, we identified amino acid sites in some important glycoproteins gB, gC, gD, and gE that may be associated with PRV adaptation to new hosts and immune escape to vaccines. Conclusions Our study provides important genetic insight into the interspecies transmission and evolution of PRV within and between different hosts that warrant additional surveillance.

The codon usage pattern can reveal the adaptive changes that allow virus survival and fitness adaptation to their particular host, as well as the external environment. Although still considered a novel influenza virus, there is an increasing number of influenza D viruses (IDVs) reported. Considering the vital role of the hemagglutinin-esterase fusion (HEF) gene in receptor binding, receptor degradation, and membrane fusion, we investigated the codon usage pattern of the IDV HEF gene to better understand its adaptive changes during evolution. Based on the HEF gene, three groups including, D/OK, D/660, and D/Japan were identified. We found a low codon usage bias, which allowed IDV to replicate in the corresponding hosts by reducing competition during evolution, that was mainly driven by natural selection and mutation pressure, with a profound role of natural selection. Furthermore, the interaction between the codon adaption index (CAI) and the relative codon deoptimization index (RCDI) revealed the adaption of IDV to multiple hosts, especially cattle which is currently considered its reservoir. Additionally, similarity index (SiD) analysis revealed that the swine exerted a stronger evolutionary pressure on IDV than cattle, though cattle is considered the primary reservoir. In addition, the conserved PB1 gene showed a similar pattern of codon usage compared to HEF. Therefore, we hypothesized that IDV has a preference to maintain infection in multiple hosts. The study aids the understanding of the evolutionary changes of IDV, which could assist this novel virus prevention and control.

TRIM family proteins play an important role in antiviral innate immunity. However, the function of chicken TRIM25 (chTRIM25) protein remains unclear. In this study, we cloned the full-length of chTRIM25 gene and analyzed its function. Sequence analysis revealed that chicken TRIM25 contained a 1902-bp open-reading frame that probably encodes a 633-amino acid protein with a molecular weight of 71.42 kD. Structural analysis demonstrated that the chTRIM25 protein had a RING finger domain (amino acids 21–66), B-box1 (amino acids 110–146), B-box2 (amino acids 160–189), a coiled-coil region (amino acids 208–311) and B30.2 domain (amino acids 465–633). The homology analysis showed that the amino acid sequence homology of chicken TRIM25 with duck and goose TRIM25 was from 74% to 77%, while the amino acid sequence homology of chicken TRIM25 with human and mouse TRIM25 was about 46%. We further found that chTRIM25 promoted type I interferon-mediated immune response to avian influenza virus in chicken fibroblast cells. This study will help us to further understand the host antiviral innate immune response to avian influenza virus in chickens.

As a renewable agricultural solid waste, Camellia oleifera nut shell (CONS) is often discarded or burned, causing adverse environmental impact and a waste of resources. The purpose of this work was to develop a CONS-based bioadsorbent for the removal of heavy metals. Both CONS and ethanol/NaOH-modified CONS (MCONS) were prepared. The specimens were characterized using physiochemical composition, Fourier transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM) coupled with energy dispersive X-ray analysis (EDX). The effects of pH, initial metal concentration, adsorbent dosage, adsorption time, and temperature on the Cr(VI) and Cu(II) removal were evaluated. The adsorption kinetics, isotherms, and thermodynamics were determined. The MCONS sample had a higher carboxyl group content and surface area than the CONS sample, which helped explain its enhanced adsorption performance of heavy metals. The maximum uptake capacity of Cr(VI) and Cu(II) was 16.39 mg/g and 27.26 mg/g for MCONS, compared with 6.34 mg/g and 9.89 mg/g for CONS. The adsorption kinetics for CONS and MCONS fit well with the pseudo-second-order kinetic model. The adsorption isotherms fit well to the Langmuir model. The thermodynamic analyses revealed that the adsorption process was spontaneous and exothermic.

Conversion of clean solar energy to chemical fuels is one of the promising and up-and-coming applications of metal–organic frameworks. However, fast recombination of photogenerated charge carriers in these frameworks remains the most significant limitation for their photocatalytic application. Although the construction of homojunctions is a promising solution, it remains very challenging to synthesize them. Herein, we report a well-defined hierarchical homojunction based on metal–organic frameworks via a facile one-pot synthesis route directed by hollow transition metal nanoparticles. The homojunction is enabled by two concentric stacked nanoplates with slightly different crystal phases. The enhanced charge separation in the homojunction was visualized by in-situ surface photovoltage microscopy. Moreover, the as-prepared nanostacks displayed a visible-light-driven carbon dioxide reduction with very high carbon monooxide selectivity, and excellent stability. Our work provides a powerful platform to synthesize capable metal–organic framework complexes and sheds light on the hierarchical structure-function relationships of metal–organic frameworks., Homojunctions are very promising in photocatalysis, but challenging to achieve. Herein, authors report a well-defined hierarchical metal–organic framework-based homojunction, formed via a one-pot synthesis route directed by hollow transition metal nanoparticles, as photocatalysts for CO2 reduction.

Amazon Germany has formulated a series of marketing strategies based on the shopping habits of German consumers and it has achieved success. This article summarizes the current marketing strategies of Amazon in Germany, and explores the key factors for the success of this marketing strategy. By comparing with other e-commerce platforms, this article critically analyzes the innovation and deficiency of Amazon in Germany.

Game animals are wildlife species often traded and consumed as exotic food, and are potential reservoirs for SARS-CoV and SARS-CoV-2. We performed a meta-transcriptomic analysis of 1725 game animals, representing 16 species and five mammalian orders, sampled across China. From this we identified 71 mammalian viruses, with 45 described for the first time. Eighteen viruses were considered as potentially high risk to humans and domestic animals. Civets (Paguma larvata) carried the highest number of potentially high risk viruses. We identified the transmission of Bat coronavirus HKU8 from a bat to a civet, as well as cross-species jumps of coronaviruses from bats to hedgehogs and from birds to porcupines. We similarly identified avian Influenza A virus H9N2 in civets and Asian badgers, with the latter displaying respiratory symptoms, as well as cases of likely human-to-wildlife virus transmission. These data highlight the importance of game animals as potential drivers of disease emergence.Highlights1725 game animals from five mammalian orders were surveyed for viruses71 mammalian viruses were discovered, 18 with a potential risk to humansCivets harbored the highest number of potential ‘high risk’ virusesA species jump of an alphacoronavirus from bats to a civet was identifiedH9N2 influenza virus was detected in a civet and an Asian badgerHumans viruses were also identified in game animals

The emergence of a novel coronavirus, SARS-CoV-2, resulted in a pandemic. Here, we used recently released X-ray structures of human ACE2 bound to the receptor-binding domain (RBD) of the spike protein (S) from SARS-CoV-2 to predict its binding to ACE2 proteins from different animals, including pets, farm animals, and putative intermediate hosts of SARS-CoV-2. Comparing the interaction sites of ACE2 proteins known to serve or not serve as receptor allows to define residues important for binding. From the 20 amino acids in ACE2 that contact S up to seven can be replaced and ACE2 can still function as the SARS-CoV-2 receptor. These variable amino acids are clustered at certain positions, mostly at the periphery of the binding site, while changes of the invariable residues prevent S-binding or infection of the respective animal. Some ACE2 proteins even tolerate the loss or the acquisition of N-glycosylation sites located near the S-interface. Of note, pigs and dogs which are not or not effectively infected, respectively, have only a few changes in the binding site have relatively low levels of ACE2 in the respiratory tract. Comparison of the RBD of S of SARS-CoV-2 with viruses from bat and pangolin revealed that the latter contains only one substitution, whereas the bat virus exhibits five. However, ACE2 of pangolin exhibit seven changes relative to human ACE2, a similar number of substitutions is present in ACE2 of bats, raccoon, and civet suggesting that SARS-CoV-2 may not especially adapted to ACE2 of any of its putative intermediate hosts. These analyses provide new insight into the receptor usage and animal source/origin of SARS-COV-2.IMPORTANCESARS-CoV-2 is threatening people worldwide and there are no drugs or vaccines available to mitigate its spread. The origin of the virus is still unclear and whether pets and livestock can be infected and transmit SARS-CoV-2 are important and unknown scientific questions. Effective binding to the host receptor ACE2 is the first prerequisite for infection of cells and determines the host range. Our analysis provides a framework for the prediction of potential hosts of SARS-CoV-2. We found that ACE2 from species known to support SARS-CoV-2 infection tolerate many amino acid changes indicating that the species barrier might be low. However, the lower expression of ACE2 in the upper respiratory tract of some pets and livestock means more research and monitoring should be done to explore the animal source of infection and the risk of potential cross-species transmission. Finally, the analysis also showed that SARS-CoV-2 may not specifically adapted to any of its putative intermediate hosts.

Expression recognition is a relatively new direction in the field of face recognition, and the knowledge involved is not only unilateral, but its in-depth research has brought benefits to the development of artificial intelligence and even to human life. In response to this, this paper intends to design an improved real-time facial expression recognition system. The design first uses a deep learning method to design a facial expression recognition model, and then embeds the OpenCV framework and the cascading face detector of the Dlib open source library, and combines the ORB feature extraction algorithm to achieve real-time detection and recognition of facial expressions. To identify robustness, this study has achieved certain results in practice. The research has certain help in the fields of psychology and education, such as the feedback of classroom students’ teaching quality and the analysis of people’s real-time expressions. The dataset used in the study was the fer2013 facial expression dataset.