50 research outputs found
Defect-unbinding transitions and inherent structures in two dimensions
We present a large-scale (36000-particle) computational study of the
"inherent structures" (IS) associated with equilibrium, two-dimensional,
one-component Lennard-Jones systems. Our results provide strong support both
for the inherent-structures theory of classical fluids, and for the KTHNY
theory of two-stage melting in two dimensions. This support comes from the
observation of three qualitatively distinct "phases" of inherent structures: a
crystal, a "hexatic glass", and a "liquid glass". We also directly observe, in
the IS, analogs of the two defect-unbinding transitions (respectively, of
dislocations, and disclinations) believed to mediate the two equilibrium phase
transitions. Each transition shows up in the inherent structures---although the
free disclinations in the "liquid glass" are embedded in a percolating network
of grain boundaries. The bond-orientational correlation functions of the
inherent structures show the same progressive loss of order as do the three
equilibrium phases: long-range to quasi-long-range to short-range.Comment: RevTeX, 8 pages, 15 figure
International Consensus Statement on Rhinology and Allergy: Rhinosinusitis
Background: The 5 years since the publication of the first International Consensus Statement on Allergy and Rhinology: Rhinosinusitis (ICARâRS) has witnessed foundational progress in our understanding and treatment of rhinologic disease. These advances are reflected within the more than 40 new topics covered within the ICARâRSâ2021 as well as updates to the original 140 topics. This executive summary consolidates the evidenceâbased findings of the document. Methods: ICARâRS presents over 180 topics in the forms of evidenceâbased reviews with recommendations (EBRRs), evidenceâbased reviews, and literature reviews. The highest grade structured recommendations of the EBRR sections are summarized in this executive summary. Results: ICARâRSâ2021 covers 22 topics regarding the medical management of RS, which are grade A/B and are presented in the executive summary. Additionally, 4 topics regarding the surgical management of RS are grade A/B and are presented in the executive summary. Finally, a comprehensive evidenceâbased management algorithm is provided. Conclusion: This ICARâRSâ2021 executive summary provides a compilation of the evidenceâbased recommendations for medical and surgical treatment of the most common forms of RS
Bacteriocin-like activity of oral Fusobacterium nucleatum isolated from human and non-human primates Atividade semelhante a bacteriocina de Fusobacterium nucleatum orais isolados de primatas humanos e nĂŁo-humanos
Fusobacterium nucleatum is indigenous of the human oral cavity and has been involved in different infectious processes. The production of bacteriocin-like substances may be important in regulation of bacterial microbiota in oral cavity. The ability to produce bacteriocin-like substances by 80 oral F. nucleatum isolates obtained from periodontal patients, healthy individuals and Cebus apella monkeys, was examinated. 17.5% of all tested isolates showed auto-antagonism and 78.8% iso- or hetero-antagonism. No isolate from monkey was capable to produce auto-inhibition. In this study, the antagonistic substances production was variable in all tested isolates. Most of the F. nucleatum showed antagonistic activity against tested reference strains. These data suggest a possible participation of these substances on the oral microbial ecology in humans and animals. However, the role of bacteriocins in regulating dental plaque microbiota in vivo is discussed.<br>Fusobacterium nucleatum Ă© indĂgena da cavidade oral humana e tem sido envolvido em diferentes processos infecciosos. A produção de substĂąncias semelhantes a bacteriocinas pode ser importante na regulação da microbiota bacteriana da cavidade oral. A capacidade de produzir substĂąncias tipo bacteriocina de 80 isolados de F. nucleatum orais, obtidos de pacientes com doença periodontal, indivĂduos sadios e macaco Cebus apella, foi avaliada. 17,5% de todos os isolados mostrou auto-antagonismo e 78,8% iso- ou hetero-antagonismo. Nenhum isolado de macaco foi capaz de produzir auto-inibição. Neste estudo, a produção de substĂąncias antagonĂstas foi variĂĄvel em todos os isolados testados. A maioria dos F. nucleatum mostrou atividade antagonĂsta para as cepas de referĂȘncia testadas. Esses dados sugerem a possĂvel participação dessas substĂąncias sobre a ecologia microbiana em humanos e animais. Entretanto, o papel das bacteriocinas na regulação da microbiota da placa dental in vivo Ă© discutida