نتایج جستجو برای: ha1
تعداد نتایج: 489 فیلتر نتایج به سال:
where w = v · v and G(1) = 1. At zero recoil (w = 1) heavy-quark symmetry requires FB→D∗(1) to be close to 1. So, |Vcb| is determined by dividing measurements of dΓ/dw by the phase space and well-known factors, and extrapolating to w → 1. This yields |Vcb|FB→D∗(1), and FB→D∗(1) is taken from “theory.” To date models [ 1] or a combination of a rigorous inequality plus judgment [ 2] have been use...
BACKGROUND The Swiss Sentinel system for influenza virus surveillance reports influenza-like illness in the community through a network of primary care practitioners, but the epidemiologic, demographic, and virological characterization may differ from that observed in hospitalized patients with influenza. OBJECTIVE To compare demographic and virological data from hospital influenza cases with...
BACKGROUND The genetic and antigenic characteristics of influenza A viruses (IAV) within and between species change over time due to antigenic shift and drift. Although pigs are known to play a key role in the epidemiology of IAV between species, little is known about the molecular evolution of IAV hemagglutinin (HA) in pigs. OBJECTIVES The aim of this study was to evaluate the HA drift of an...
1-Chlorohexane halidohydrolase from Arthrobacter sp. strain HA1 was purified to homogeneity by fractional precipitation, ion-exchange chromatography, gel filtration, and high-performance liquid chromatography gel filtration. The enzyme was a monomer with a molecular weight of about 37,000; its amino acid composition and N-terminal sequence were determined. The enzyme had a broad optimum around ...
Quantifying adaptive evolution at the genomic scale is an essential yet challenging aspect of evolutionary biology. Here, we develop a method that extends and generalizes previous approaches to estimate the rate of genomic adaptation in rapidly evolving populations and apply it to a large data set of complete human influenza A virus genome sequences. In accord with previous studies, we observe ...
OBJECTIVE To use functional magnetic resonance imaging to map the auditory cortical fields that are activated, or nonreactive, to sounds in patient M.L., who has auditory agnosia caused by trauma to the inferior colliculi. BACKGROUND The patient cannot recognize speech or environmental sounds. Her discrimination is greatly facilitated by context and visibility of the speaker's facial movement...
As HIV-1-encoded envelope protein traverses the secretory pathway, it may be modified with N- and O-linked carbohydrate. When the gp120s of HIV-1 NL4-3, HIV-1 YU2, HIV-1 Bal, HIV-1 JRFL, and HIV-1 JRCSF were expressed as secreted proteins, the threonine at consensus position 499 was found to be O-glycosylated. For SIVmac239, the corresponding threonine was also glycosylated when gp120 was recom...
Epidemics of influenza A vary greatly in size and age distribution of cases, and this variation is attributed to varying levels of pre-existing immunity. Recent studies have shown that antibody-mediated immune responses are more cross-reactive than previously believed, and shape patterns of humoral immunity to influenza A viruses over long periods. Here we quantify antibody responses to the hem...
Current influenza vaccines are produced in embryonated chicken eggs. However, egg-based vaccines have various problems. To address these problems, recombinant protein vaccines have been developed as new vaccine candidates. Unfortunately, recombinant proteins frequently encounter aggregation and low stability during their biogenesis. It has been previously demonstrated that recombinantly express...
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