20 research outputs found

    Nodal Landau Fermi-Liquid Quasiparticles in Overdoped La1.77_{1.77}Sr0.23_{0.23}CuO4_4

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    Nodal angle resolved photoemission spectra taken on overdoped La1.77_{1.77}Sr0.23_{0.23}CuO4_4 are presented and analyzed. It is proven that the low-energy excitations are true Landau Fermi-liquid quasiparticles. We show that momentum and energy distribution curves can be analyzed self-consistently without quantitative knowledge of the bare band dispersion. Finally, by imposing Kramers-Kronig consistency on the self-energy Σ\Sigma, insight into the quasiparticle residue is gained. We conclude by comparing our results to quasiparticle properties extracted from thermodynamic, magneto-resistance, and high-field quantum oscillation experiments on overdoped Tl2_2Ba2_2CuO6+δ_{6+\delta}.Comment: Accepted for publication in Phys. Rev.

    An Integrated Metabolomic and Genomic Mining Workflow to Uncover the Biosynthetic Potential of Bacteria

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    Microorganisms are a rich source of bioactives; however, chemical identification is a major bottleneck. Strategies that can prioritize the most prolific microbial strains and novel compounds are of great interest. Here, we present an integrated approach to evaluate the biosynthetic richness in bacteria and mine the associated chemical diversity. Thirteen strains closely related to Pseudoalteromonas luteoviolacea isolated from all over the Earth were analyzed using an untargeted metabolomics strategy, and metabolomic profiles were correlated with whole-genome sequences of the strains. We found considerable diversity: only 2% of the chemical features and 7% of the biosynthetic genes were common to all strains, while 30% of all features and 24% of the genes were unique to single strains. The list of chemical features was reduced to 50 discriminating features using a genetic algorithm and support vector machines. Features were dereplicated by tandem mass spectrometry (MS/MS) networking to identify molecular families of the same biosynthetic origin, and the associated pathways were probed using comparative genomics. Most of the discriminating features were related to antibacterial compounds, including the thiomarinols that were reported from P. luteoviolacea here for the first time. By comparative genomics, we identified the biosynthetic cluster responsible for the production of the antibiotic indolmycin, which could not be predicted with standard methods. In conclusion, we present an efficient, integrative strategy for elucidating the chemical richness of a given set of bacteria and link the chemistry to biosynthetic genes. IMPORTANCE We here combine chemical analysis and genomics to probe for new bioactive secondary metabolites based on their pattern of distribution within bacterial species. We demonstrate the usefulness of this combined approach in a group of marine Gram-negative bacteria closely related to Pseudoalteromonas luteoviolacea, which is a species known to produce a broad spectrum of chemicals. The approach allowed us to identify new antibiotics and their associated biosynthetic pathways. Combining chemical analysis and genetics is an efficient “mining” workflow for identifying diverse pharmaceutical candidates in a broad range of microorganisms and therefore of great use in bioprospecting

    Evaluation of quadrivalent HPV 6/11/16/18 vaccine efficacy against cervical and anogenital disease in subjects with serological evidence of prior vaccine type HPV infection

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    Objective: In the quadrivalent (types 6/11/16/18) HPV vaccine (GARDASIL®/SILGARD®) clinical program, 73% of women aged 16-26 were naïve to all vaccine HPV types. In these women, prophylactic administration of the vaccine was highly effective in preventing HPV 6/11/16/18-related cervical disease. Of the remaining women, 15% of had evidence of past infection with one or more vaccine HPV types (seropositive and DNA negative) at the time of enrollment. Here we present an analysis in this group of women to determine the efficacy of the HPV 6/11/16/18 vaccine against new cervical and external anogenital disease related to the same vaccine HPV type which had previously been cleared. Vaccine tolerability in this previously infected population was also assessed. Results: Subjects were followed for an average of 40 months. Seven subjects in the placebo group developed cervical disease, and eight subjects developed external genital disease related to a vaccine HPV type they had previously encountered. No subject receiving HPV 6/11/16/18 vaccine developed disease to a vaccine HPV type to which they were seropositive and DNA negative at enrollment. Methods: 18,174 women were enrolled into three clinical studies. The data presented comprise a subset of these subjects (n = 2,617) who were HPV seropositive and DNA negative at enrollment (for ?1 vaccine type). In each study, subjects were randomized in a 1:1 ratio to receive HPV 6/11/16/18 vaccine or placebo at day 1, month 2 and month 6 (without knowledge of baseline HPV status). Procedures performed for efficacy data evaluation included detailed genital examination, Pap testing and collection of cervicovaginal and external genital specimens. Analyses of efficacy were carried out in a population stratified by HPV serology and HPV DNA status at enrollment. Conclusions: These results suggest that natural HPV infection-elicited antibodies may not provide complete protection over time, however the immune response to the HPV 6/11/16/18 vaccine appears to prevent reinfection or reactivation of disease with vaccine HPV types. Vaccine-related adverse experiences were higher among subjects receiving vaccine, mostly due to increased injection site adverse experiences. © 2009 Landes Bioscience

    Evaluation of quadrivalent HPV 6/11/16/18 vaccine efficacy against cervical and anogenital disease in subjects with serological evidence of prior vaccine type HPV infection

    No full text
    Objective: In the quadrivalent (types 6/11/16/18) HPV vaccine (GARDASIL®/SILGARD®) clinical program, 73% of women aged 16-26 were naïve to all vaccine HPV types. In these women, prophylactic administration of the vaccine was highly effective in preventing HPV 6/11/16/18-related cervical disease. Of the remaining women, 15% of had evidence of past infection with one or more vaccine HPV types (seropositive and DNA negative) at the time of enrollment. Here we present an analysis in this group of women to determine the efficacy of the HPV 6/11/16/18 vaccine against new cervical and external anogenital disease related to the same vaccine HPV type which had previously been cleared. Vaccine tolerability in this previously infected population was also assessed. Results: Subjects were followed for an average of 40 months. Seven subjects in the placebo group developed cervical disease, and eight subjects developed external genital disease related to a vaccine HPV type they had previously encountered. No subject receiving HPV 6/11/16/18 vaccine developed disease to a vaccine HPV type to which they were seropositive and DNA negative at enrollment. Methods: 18,174 women were enrolled into three clinical studies. The data presented comprise a subset of these subjects (n = 2,617) who were HPV seropositive and DNA negative at enrollment (for ≥1 vaccine type). In each study, subjects were randomized in a 1:1 ratio to receive HPV 6/11/16/18 vaccine or placebo at day 1, month 2 and month 6 (without knowledge of baseline HPV status). Procedures performed for efficacy data evaluation included detailed genital examination, Pap testing and collection of cervicovaginal and external genital specimens. Analyses of efficacy were carried out in a population stratified by HPV serology and HPV DNA status at enrollment. Conclusions: These results suggest that natural HPV infection-elicited antibodies may not provide complete protection over time, however the immune response to the HPV 6/11/16/18 vaccine appears to prevent reinfection or reactivation of disease with vaccine HPV types. Vaccine-related adverse experiences were higher among subjects receiving vaccine, mostly due to increased injection site adverse experiences. © 2009 Landes Bioscience.link_to_OA_fulltex
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