In order to determine gene frequencies of human platelet antigen (HPA) and establish a panel of accredited HPA-1a, -2a, -4a, -5a and -6a-negative donors as well as an HPA-typed platelet donor registry, a total of 1000 Chinese donors of Han nationality (500 from north China and 500 from south China) were typed for HPA-1 through -16 using a DNA-based polymerase chain reaction with sequence-specific primers genotyping method. The gene frequencies of HPA-1b, -2b, -3b, -4b, -5b, -6bw, -10bw and -15b were 0.0060, 0.0485, 0.4055, 0.0045, 0.0140, 0.0135, 0.0005 and 0.4680, respectively. The HPA-7bw, -8bw, -9bw, -11bw, -12bw, -13bw, -14bw and -16bw alleles were not found. The HPA-2b and -5b homozygous donors were detected at low frequencies. The HPA mismatch probabilities potentially leading to alloimmunization in random platelet transfusion vary with a region from 0.1% to 37% depending on the distribution patterns of common and less common alleles in each system. This study provides a useful HPA-typed plateletpheresis donor registry in China and could improve platelet antibody detection and HPA-matched platelet transfusion in alloimmune thrombocytopenic patients.

H9N2 influenza virus is undergoing extensive genetic and antigenic evolution, warranting detailed antigenic mapping of its hemagglutinin (HA). Through examining antibody escape mutants of an Asian avian H9N2 virus, we identified 9 critical amino acid positions in H9 antigenic sites. Five of these positions, 164, 167, 168, 196, and 207, have not been reported previously and, thus, represent novel molecular markers for monitoring the antigenic change of H9N2 virus. H9N2 influenza virus is circulating in poultry worldwide. H9N2 virus infection is usually mild in nature but may lead to higher mortality if it is associated with secondary infection (1, 2). In Asia, since its introduction into land-based poultry in the late 1980s, H9N2 virus has been spreading to various avian and mammalian species, including pigs (3, 4). Due to the Q226L mutation (change of Gln to Leu at position 226) in the hemagglutinin (HA) (5-7), a significant proportion of H9N2 isolates have acquired human virus-like receptor specificity (5,8). Consistent with this receptor specificity change, multiple human cases of H9N2 virus infection have been reported (9-12). Moreover, H9N2 virus has provided internal genes for the highly pathogenic H5N1 (9, 13, 14) and novel H7N9 (15) viruses. These have put H9N2 virus high on the list of influenza viruses with pandemic potential.Although the crystal structure of H9 has been solved (16), no details for H9 antigenic epitopes have been elucidated. Previous investigations by other groups have identified multiple amino acids in H9 antigenic sites (17, 18). These are nevertheless far from being sufficient for understanding the H9 antigenic structure. To identify more amino acids constituting H9 antigenic sites, we performed an antigenic mapping of the HA of an avian H9N2 virus A/Chicken/Jiangsu/X1/2004 (hereinafter called X1) (GenBank nucleotide sequence accession number KF688983) with monoclonal antibodies (MAbs).H9-specific MAbs were generated through the fusion of myeloma Sp2/0 cells with splenocytes from a BALB/c mouse immunized with X1 virus (19). The immunization included 3 intraperitoneal inoculations at 2-week intervals and a final boost with live X1 virus (on day 3 before the fusion). Hybridomas were screened by indirect immunofluorescence assay using chicken embryo fibroblast cells infected with X1 virus as the antigen, followed by screening with a hemagglutination inhibition (HI) assay using 4 hemagglutination units of X1 virus (20). Ascitic fluid of each selected hybridoma was generated in mice and used directly (e.g., without further purification or treatment with receptor-destroying enzyme) in the characterization of each MAb. All animal experiments were done in accordance with the institutional animal care guidelines, and the protocol (number 06R015) was approved by the Animal Care Committee at Yangzhou University. A microneutralization (MN) assay was performed in Madin-Darby canine kidney (MDCK) cells, following a previous protocol (21), except that 100 median tissue infectious doses (TCID 50 ) o...

Molecular hydrogen is one of the essential reactants in the chemical industry, and its generation from renewable sources such as biomass materials and water is of great benefit to the future society. Generally, molecular oxygen should be pre-eliminated in the hydrogen evolution reactions (HERs) in order to avoid the reverse hydrogen oxidation reaction (HOR). Here, we report a highly efficient HER from a formaldehyde/water mixture using MgO supported Ag nanoparticles (AgNPs/MgO) as the catalyst and molecular oxygen as a promoter. The HER rate depends almost linearly on the oxygen partial pressure, and the optimal turnover frequency (TOF) of the silver catalyst exceeds 6,600 h–1. Based on the experimental and theoretical results, a surface stabilized MgO/Ag–•OOH complex is suggested to be the main catalytically active species for the HER.

Strong metal–support interaction (SMSI) is a phenomenon commonly observed on heterogeneous catalysts. Here, direct evidence of SMSI between noble metal and 2D TiB2 supports is reported. The temperature‐induced TiB2 overlayers encapsulate the metal nanoparticles, resulting in core–shell nanostructures that are sintering‐resistant with metal loadings as high as 12.0 wt%. The TiOx‐terminated TiB2 surfaces are the active sites catalyzing the dehydrogenation of formic acid at room temperature. In contrast to the trade‐off between stability and activity in conventional SMSI, TiB2‐based SMSI promotes catalytic activity and stability simultaneously. By optimizing the thickness and coverage of the overlayer, the Pt/TiB2 catalyst displays an outstanding hydrogen productivity of 13.8 mmol g−1cat h−1 in 10.0 m aqueous solution without any additive or pH adjustment, with >99.9% selectivity toward CO2 and H2. Theoretical studies suggest that the TiB2 overlayers are stabilized on different transition metals through an interplay between covalent and electrostatic interactions. Furthermore, the computationally determined trends in metal–TiB2 interactions are fully consistent with the experimental observations regarding the extent of SMSI on different transition metals. The present research introduces a new means to create thermally stable and catalytically active metal/support interfaces for scalable chemical and energy applications.