Comparison of nonhuman primates identified the suitable model for COVID-19

Identification of a suitable nonhuman primate(NHP)model of COVID-19 remains challenging.Here,we characterized severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection in three NHP species:Old World monkeys Macaca mulatta(M.mulatta)and Macaca fascicularis(M.fascicularis)and New World monkey Callithrix jacchus(C.jacchus).Infected M.mulatta and M.fascicularis showed abnormal chest radiographs,an increased body temperature and a decreased body weight.Viral genomes were detected in swab and blood samples from all animals.Viral load was detected in the pulmonary tissues of M.mulatta and M.fascicularis but not C.jacchus.Furthermore,among the three animal species,M.mulatta showed the strongest response to SARS-CoV-2,including increased inflammatory cytokine expression and pathological changes in the pulmonary tissues.Collectively,these data revealed the different susceptibilities of Old World and New World monkeys to SARS-CoV-2 and identified M.mulatta as the most suitable for modeling COVID-19.

A multi-step induced strategy to fabricate core-shell Pt-Ni alloy as symmetric electrocatalysts for overall water splitting

Devising an electrocatalyst with brilliant efficiency and satisfactory durability for hydrogen production is of considerable demand,especially for large-scale application.Herein,we adopt a multi-step consequential induced strategy to construct a bifunctional electrocatalyst for the overall water splitting.Graphene oxide(GO)was used as a carbon matrix and in situ oxygen source,which was supported by the octahedral PtNi alloy to form the PtxNiy-GO precursor.When calcinating in Ar atmosphere,the oxygen in GO induced the surface segregation of Ni from the PtNi octahedron to form a core-shell structure of Ptx@Niy.Then,the surface-enriched Ni continuously induced the reformation of C in reduced graphene oxide(rGO)to enhance the degree of graphitization.This multi-step induction formed a nanocatalyst Pt_(x)@Ni_(y)-rGO which has very high catalytic efficiency and stability.By optimizing the feeding ratio of PtNi(Pt:Ni=1:2),the electrolytic overall water splitting at 10 mA·cm^(-2) can be driven by an electrolytic voltage of as low as 1.485 V,and hydrogen evolution reaction(HER)only needs an overpotential of 37 mV in 1.0 M KOH aqueous solution.Additionally,the catalyst exhibited consistent existence form in both HER and oxygen evolution reaction(OER),which was verified by switching the anode and cathode of the cell in the electrolysis of water.This work provides a new idea for the synthesis and evaluation of the bifunctional catalysts for water splitting.

The olfactory route is a potential way for SARS-CoV-2 to invade the central nervous system of rhesus monkeys

Neurological manifestations are frequently reported in the COVID-19 patients.Neuromechanism of SARS-CoV-2 remains to be elucidated.In this study,we explored the mechanisms of SARS-CoV-2 neurotropism via our established non-human primate model of COVID-19.In rhesus monkey,SARS-CoV-2 invades the CNS primarily via the olfactory bulb.Thereafter,viruses rapidly spread to functional areas of the central nervous system,such as hippocampus,thalamus,and medulla oblongata.The infection of SARS-CoV-2 induces the inflammation possibly by targeting neurons,microglia,and astrocytes in the CNS.Consistently,SARS-CoV-2 infects neuro-derived SK-N-SH,glial-derived U251,and brain microvascular endothelial cells in vitro.To our knowledge,this is the first experimental evidence of SARS-CoV-2 neuroinvasion in the NHP model,which provides important insights into the CNS-related pathogenesis of SARS-CoV-2.

Pseudo Color Fusion of Infrared and Visible Images Based on the Rattlesnake Vision Imaging System

Image fusion is a key technology in the field of digital image processing.In the present study,an effect-based pseudo color fusion model of infrared and visible images based on the rattlesnake vision imaging system(the rattlesnake bimodal cell fusion mechanism and the visual receptive field model)is proposed.The innovation point of the proposed model lies in the following three features:first,the introduction of a simple mathematical model of the visual receptive field reduce computational complexity;second,the enhanced image is obtained by extracting the common information and unique information of source images,which improves fusion image quality;and third,the Waxman typical fusion structure is improved for the pseudo color image fusion model.The performance of the image fusion model is verified through comparative experiments.In the subjective visual evaluation,we find that the color of the fusion image obtained through the proposed model is natural and can highlight the target and scene details.In the objective quantitative evaluation,we observe that the best values on the four indicators,namely standard deviation,average gradient,entropy,and spatial frequency,accounts for 90%,100%,90%,and 100%,respectively,indicating that the fusion image exhibits superior contrast,image clarity,information content,and overall activity.Experimental results reveal that the performance of the proposed model is superior to that of other models and thus verified the validity and reliability of the model.

Reverse genetics in virology:A double edged sword

Reverse genetics via targeted modification of gene sequences to obtain a phenotype and the inference of a gene's function or regulatory mechanism is widely used as a potent tool in viral biology and application.However,while reverse genetics has contributed significantly to our understanding of molecular biology and the pathogenesis of viruses,its accessibility(operation)and openness(data)have raised many concerns regarding biosafety and biosecurity.In this review,we retrospectively examine the development of reverse genetics and its applications in virology,then emphasize global biosafety and biosecurity concerns regarding reverse genetics,and summarize global regulations,governance,and laws on reverse genetics.This review seeks to enhance our understanding and rational application of reverse genetics technology for the benefit of humankind.

Advanced Flexible Carbon‑Based Current Collector for Zinc Storage

Carbon cloth(CC)-based electrodes have attracted extensive attention for next-generation wearable energy-storage devices due to their excellent electrical conductivity and mechanical flexibility.However,the application of conventional CC-based electrodes for zinc(Zn)storage severely hinders Zn ion transport and induces deleterious Zn dendrite growth,resulting in poor electrochemical reliability.Herein,a novel oxygen plasma-treated carbon cloth(OPCC)is rationally designed as a current collector for flexible hybrid Zn ion supercapacitors(ZISs).The modified interface of OPCC with abundant oxygenated groups enables enhanced electrolyte wettability and uniform superficial electric field distribution.A prolonged working lifespan for Zn electrodeposition is achieved by the OPCC due to the improved interfacial kinetics and homogenized ion gradient.The as-prepared hybrid ZIS also delivers excellent cycling endurance(98.5%capacity retention for 1500 cycles)with outstanding operation stability under various extreme conditions.This facile surface modification strategy provides a new way for developing future flexible electrodes for wearable electronic products.

Three doses of prototypic SARS-CoV-2 inactivated vaccine induce cross-protection against its variants of concern

Variants are globally emerging very quickly following pandemic prototypic SARS-CoV-2.To evaluate the cross-protection of prototypic SARS-CoV-2 vaccine against its variants,we vaccinated rhesus monkeys with three doses of prototypic SARS-CoV-2 inactivated vaccine,followed by challenging with emerging SARS-CoV-2 variants of concern(VOCs).

Short sellers' accusations against Chinese reverse mergers: Information analytics or guilt by association?

This paper studies short sellers' trading strategies and their effects on the financial market by examining their accusations of fraud against Chinese reverse merger firms(CRMs) in the US. We find that short sellers rely on firms' fundamental information, especially relative financial indicators, to locate their "prey." Specifically, they compare a target firm's financial indicators(e.g., growth and receivables) with both the industry average and the firm's history. We find no evidence that short sellers accuse CRMs simply because of their reverse merger label. Additionally, we test the accuracy of short sellers' accusations in the long run and find that accused firms are more likely to delist and less likely to recover from price plunges. Our results also indicate that CRMs' high exposure to short sellers' accusations stem from adverse selection problems: firms with high litigation risk are more likely to choose reverse mergers to access the US capital market. Overall, our results support the view that short sellers are sophisticated investors and shed some light on their decision processes.