Avian influenza viruses preferentially recognize sialosugar chains terminating in sialic acid-␣2,3-galactose (SA␣2,3Gal), whereas human influenza viruses preferentially recognize SA␣2,6Gal. A conversion to SA␣2,6Gal specificity is believed to be one of the changes required for the introduction of new hemagglutinin (HA) subtypes to the human population, which can lead to pandemics. Avian influenza H5N1 virus is a major threat for the emergence of a pandemic virus. As of 12 June 2007, the virus has been reported in 45 countries, and 312 human cases with 190 deaths have been confirmed. We describe here substitutions at position 129 and 134 identified in a virus isolated from a fatal human case that could change the receptor-binding preference of HA of H5N1 virus from SA␣2,3Gal to both SA␣2,3Gal and SA␣2,6Gal. Molecular modeling demonstrated that the mutation may stabilize SA␣2,6Gal in its optimal cis conformation in the binding pocket. The mutation was found in approximately half of the viral sequences directly amplified from a respiratory specimen of the patient. Our data confirm the presence of H5N1 virus with the ability to bind to a human-type receptor in this patient and suggest the selection and expansion of the mutant with human-type receptor specificity in the human host environment.

Iron sulfides have been attracting great attention as anode materials for highperformance rechargeable sodium-ion batteries due to their high theoretical capacity and low cost. In practice, however, they deliver unsatisfactory performance because of their intrinsically low conductivity and volume expansion during charge-discharge processes. Here, a facile in situ synthesis of a 3D interconnected FeS@Fe 3 C@graphitic carbon (FeS@Fe 3 C@GC) composite via chemical vapor deposition (CVD) followed by a sulfuration strategy is developed. The construction of the double-layered Fe 3 C/GC shell and the integral 3D GC network benefits from the catalytic effect of iron (or iron oxides) during the CVD process. The unique nanostructure offers fast electron/Na ion transport pathways and exhibits outstanding structural stability, ensuring fast kinetics and long cycle life of the FeS@Fe 3 C@GC electrodes for sodium storage. A similar process can be applied for the fabrication of various metal oxide/carbon and metal sulfide/carbon electrode materials for high-performance lithium/sodium-ion batteries.

Edible bird's nest (EBN) is the nest of the swift that is made from its saliva. Although EBN has been widely used for enhancing immunocompetence, its antiviral efficacy has not been studied in detail. We found that EBN extract could strongly inhibit infection with influenza viruses in a host range-independent manner when it was hydrolyzed with Pancreatin F. Western blotting assay showed that the EBN extract bound to influenza virus. Furthermore, EBN extract could neutralize the infection of MDCK cells with influenza viruses and inhibit hemagglutination of influenza viruses to erythrocytes, but it could not inhibit the activity of influenza virus sialidase. Fluorometric HPLC indicated that the major molecular species of sialic acid in EBN is N-acetylneuraminic acid. The results suggest that EBN is a safe and valid natural source for the prevention of influenza viruses.

Heterostructures are attractive for advanced energy storage devices due to their rapid charge transfer kinetics, which is of benefit to the rate performance. The rational and facile construction of heterostructures with satisfactory electrochemical performance, however, is still a great challenge. Herein, ultrafine hetero-CoO/Co 3 S 4 nanoparticles embedded in N-doped carbon frameworks (CoO/Co 3 S 4 @N-C) are successfully obtained by employing metal-organic frameworks as precursors. As anodes for sodium ion batteries, the CoO/Co 3 S 4 @N-C electrodes exhibit high specific capacity (1029.5 mA h g −1 at 100 mA g −1 ) and excellent rate capability (428.0 mA h g −1 at 5 A g −1 ), which may be attributed to their enhanced electric conductivity, facilitated Na + transport, and intrinsic structural stability. Density functional theoretical calculations further confirm that the constructed heterostructures induce electric fields and promote fast reaction kinetics in Na + transport. This work provides a feasible approach to construct metal oxide/sulfide heterostructures toward high-performance metal-ion batteries.

cell design have presented numerous safety hazards and economic challenges, [3][4][5] which make LIBs less suitable for largescale applications. Compared with organic LIBs, aqueous rechargeable Zn-ion batteries (ZIBs) equipped with nonflammable and highly ion conductive aqueous electrolytes are highly desirable. They benefit from a high theoretical capacity (a gravimetric capacity of 820 mAh g −1 and a volumetric capacity of 5855 mAh cm −3 ) and a low plating/stripping potential (−0.76 V vs standard hydrogen electrode), as well as a high natural abundance of metallic Zn. [6][7][8] Unfortunately, the uncontrolled formation of dendrites, undesired side reactions (e.g., corrosion, hydrogen evolution, and by-product formation), and huge volume variation during repeated Zn deposition-dissolution processes of the host-less metallic Zn anode not only limit the efficiency of plating and stripping, but also result in a remarkably short lifespan, or even internal short-circuiting. [9][10][11] In order to address the issues mentioned above, several strategies have been proposed to regulate the Zn plating/stripping behaviors for stable Zn metal batteries, including surface modification, [12][13][14] electrolyte optimization, [15][16][17] and electrode structural design. [18][19][20] For instance, an ultrathin MXene layer and glucose have been used as an artificial layer and a multifunctional electrolyte additive to stabilize Zn metal anodes, Aqueous Zn metal batteries have attracted much attention due to their high intrinsic capacity, high safety, and low cost. Nevertheless, uncontrollable dendrite growth and adverse side reactions of Zn anodes seriously hinder their further application. Herein, a three-dimensional (3D) porous graphene-carbon nanotubes scaffold decorated with metal-organic framework derived ZnO/C nanoparticles (3D-ZGC) is fabricated as the host for dendrite-free Zn-metal composite anodes. The zincophilic ZnO/C nanoparticles act as preferred deposition sites with low nucleation barriers to induce homogeneous Zn deposition. The mechanically robust 3D scaffold with high conductivity not only suppresses the formation of dendritic Zn by reducing the local current density and homogenizing Zn 2+ ion flux, but also inhibits volume changes during the long-term plating/stripping process. As a result, the 3D-ZGC composite anodes afford unprecedented Zn plating-stripping stability at an ultrahigh current density of 20 mA cm -2 for 1500 cycles with low overpotential (<65 mV) when used in a symmetric cell. When coupled with MnO 2 cathodes, the assembled Zn@3D-ZGC//MnO 2 full batteries deliver an enhanced cycling stability for up to 6000 cycles at 2000 mA g -1 , demonstrating the potential of the 3D-ZGC composite anode for advanced Zn metal batteries.

Carbon dots (CDs) are a new type of carbon nanomaterial that have unique physical and chemical properties, good biocompatibility, low toxicity, easy surface functionalization, making them widely used in biological...

Zn-based aqueous batteries (ZABs) have been regarded as promising candidates for safe and large-scale energy storage in the "post-Li" era. However, kinetics and stability problems of Zn capture cannot be concomitantly regulated, especially at high rates and loadings. Herein, a hierarchical confinement strategy is proposed to design zincophilic and spatial traps through a host of porous Co-embedded carbon cages (denoted as CoCC). The zincophilic Co sites act as preferred nucleation sites with low nucleation barriers (within 0.5 mA h cm −2 ), and the carbon cage can further spatially confine Zn deposition (within 5.0 mA h cm −2 ). Theoretical simulations and in situ/ ex situ structural observations reveal the hierarchical spatial confinement by the elaborated all-in-one network (within 12 mA h cm −2 ). Consequently, the elaborate strategy enables a dendrite-free behavior with excellent kinetics (low overpotential of ca. 65 mV at a high rate of 20 mA cm −2 ) and stable cycle life (over 800 cycles), pushing forward the next-generation high-performance ZABs.

Rotavirus is the most common cause of severe gastroenteritis in infants and children worldwide. The cell attachment of most animal rotaviruses, which belong to the neuraminidase-sensitive strains, requires sialic acid residues on the host cell membranes. On the other hand, most human rotaviruses are classified as neuraminidase-insensitive strains. The involvement of gangliosides on the host cell surface in human rotavirus infection was investigated by immunostaining analysis of target cells, and by assaying the neutralization of infection by rotavirus and the blocking of target cellular receptors. In host cells (MA104 cells) pretreated with Arthrobacter ureafaciens neuraminidase, which were still infected by human rotaviruses (KUN and MO strains), GM(3) was hydrolyzed markedly by the neuraminidase, while GM(1a) was not hydrolyzed at all. Infection by the rotaviruses was strongly inhibited by exogenous ganglioside GM(1a), but not GA(1). Infection was also inhibited by pretreatment of the MA104 cells with cholera toxin B-subunit, which specifically blocked ganglioside GM(1a) on the plasma membrane. The treatment of MA104 cells with the endoglycoceramidase attenuated human rotavirus infection. From these findings, we concluded that GM(1a) on the plasma membrane of the host cells was involved in the infection by human rotavirus KUN and MO strains.