239 research outputs found

    Coiled phononic crystal with periodic rotational locking: subwavelength bragg band gaps

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    Phononic crystals (PnC) are spatially periodic materials with band gaps that form by Bragg scattering of elastic waves. Within the frequency range of a band gap, wave propagation is not admitted. A long-standing limitation of this class of materials is that the wavelength for band-gap formation must be on the order of the unit-cell size. This restricts the presence of band gaps to relatively high frequencies for a given lattice spacing. Locally resonant metamaterials, on the other hand, enable the opening of low-frequency, subwavelength band gaps through resonance hybridization. However, their band gaps are characteristically narrow and require large or massive local resonators to form. Here, we break both limitations using beam-based PnCs by (1) locking the rotation degree of freedom at the edges of the primitive unit cell, and (2) coiling the PnC by applying full beam-axis rotations at the locked locations. These respective kinematic and geometric transformations convert a conventional beam PnC from its extended form with a nominal lattice constant to an extremely compact coiled configuration with a greatly reduced lattice constant. With the periodic rotational locking, the band gaps remain intact and are still large, and in fact increase noticeably in size. With the subsequent coiling, the band gaps remain based on Bragg scattering and are quantitatively conserved except now appearing at lower frequencies as dictated by the ratio of the extended-to-coiled lattice constants. This ratio defines a coiling factor, which is a measure of the reduction in the PnC unit-cell length in the direction of wave transmission while maintaining the band structure of its original extended form except for the favorable changes induced by the periodic rotational locking. A coiling factor of ß lowers, by construction, the location of the normalized central frequency of any given band gap by a factor of ß . The only limitation is the need for lateral space to accommodate the coiling of the beam segments. The vibration behavior of a finite version of the coiled structure is experimentally tested demonstrating a matching band-gap response, despite the reduction in length, to that obtained by finite-element analysis of the extended rotationally locked version. This concept creates effectively subwavelength Bragg band gaps. It clears the path for PnCs to serve in applications that are orders-of-magnitude smaller in scale than are currently possible, while featuring band gaps that are significantly larger than those generated by locally resonant metamaterials.This research is funded by the Air Force Office of Scientific Research under grant number 20RXCOR058.Peer ReviewedPostprint (author's final draft

    Psychosocial predictors of doping intentions and use in sport and exercise: a systematic review and meta-analysis

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    Objective: To conduct a meta-analytic review of psychosocial predictors of doping intention, doping use and inadvertent doping in sport and exercise settings. Design: Systematic review and meta-analysis. Data sources: Scopus, Medline, Embase, PsychINFO, CINAHL Plus, ProQuest Dissertations/Theses and Open Grey. Eligibility criteria: Studies (of any design) that measured the outcome variables of doping intention, doping use and/or inadvertent doping and at least one psychosocial determinant of those three variables. Results: We included studies from 25 experiments (N=13 586) and 186 observational samples (N=3 09 130). Experimental groups reported lower doping intentions (g=−0.21, 95% CI (−0.31 to –0.12)) and doping use (g=−0.08, 95% CI (−0.14 to –0.03), but not inadvertent doping (g=−0.70, 95% CI (−1.95 to 0.55)), relative to comparators. For observational studies, protective factors were inversely associated with doping intentions (z=−0.28, 95% CI −0.31 to –0.24), doping use (z=−0.09, 95% CI −0.13 to to –0.05) and inadvertent doping (z=−0.19, 95% CI −0.32 to –0.06). Risk factors were positively associated with doping intentions (z=0.29, 95% CI 0.26 to 0.32) and use (z=0.17, 95% CI 0.15 to 0.19), but not inadvertent doping (z=0.08, 95% CI −0.06 to 0.22). Risk factors for both doping intentions and use included prodoping norms and attitudes, supplement use, body dissatisfaction and ill-being. Protective factors for both doping intentions and use included self-efficacy and positive morality. Conclusion: This study identified several protective and risk factors for doping intention and use that may be viable intervention targets for antidoping programmes. Protective factors were negatively associated with inadvertent doping; however, the empirical volume is limited to draw firm conclusions

    Psychosocial predictors of doping intentions and use in sport and exercise: a systematic review and meta-analysis

    Get PDF
    Objective: To conduct a meta-analytic review of psychosocial predictors of doping intention, doping use and inadvertent doping in sport and exercise settings. Design: Systematic review and meta-analysis. Data sources: Scopus, Medline, Embase, PsychINFO, CINAHL Plus, ProQuest Dissertations/Theses and Open Grey. Eligibility criteria: Studies (of any design) that measured the outcome variables of doping intention, doping use and/or inadvertent doping and at least one psychosocial determinant of those three variables. Results: We included studies from 25 experiments (N=13 586) and 186 observational samples (N=3 09 130). Experimental groups reported lower doping intentions (g=−0.21, 95% CI (−0.31 to –0.12)) and doping use (g=−0.08, 95% CI (−0.14 to –0.03), but not inadvertent doping (g=−0.70, 95% CI (−1.95 to 0.55)), relative to comparators. For observational studies, protective factors were inversely associated with doping intentions (z=−0.28, 95% CI −0.31 to –0.24), doping use (z=−0.09, 95% CI −0.13 to to –0.05) and inadvertent doping (z=−0.19, 95% CI −0.32 to –0.06). Risk factors were positively associated with doping intentions (z=0.29, 95% CI 0.26 to 0.32) and use (z=0.17, 95% CI 0.15 to 0.19), but not inadvertent doping (z=0.08, 95% CI −0.06 to 0.22). Risk factors for both doping intentions and use included prodoping norms and attitudes, supplement use, body dissatisfaction and ill-being. Protective factors for both doping intentions and use included self-efficacy and positive morality. Conclusion: This study identified several protective and risk factors for doping intention and use that may be viable intervention targets for antidoping programmes. Protective factors were negatively associated with inadvertent doping; however, the empirical volume is limited to draw firm conclusions

    Analysis of two large functionally uncharacterized regions in the Methanopyrus kandleri AV19 genome

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    Background: For most sequenced prokaryotic genomes, about a third of the protein coding genes annotated are "orphan proteins", that is, they lack homology to known proteins. These hypothetical genes are typically short and randomly scattered throughout the genome. This trend is seen for most of the bacterial and archaeal genomes published to date.Results: In contrast we have found that a large fraction of the genes coding for such orphan proteins in the Methanopyrus kandleri AV19 genome occur within two large regions. These genes have no known homologs except from other M. kandleri genes. However, analysis of their lengths, codon usage, and Ribosomal Binding Site (RBS) sequences shows that they are most likely true protein coding genes and not random open reading frames.Conclusions: Although these regions can be considered as candidates for massive lateral gene transfer, our bioinformatics analysis suggests that this is not the case. We predict many of the organism specific proteins to be transmembrane and belong to protein families that are non-randomly distributed between the regions. Consistent with this, we suggest that the two regions are most likely unrelated, and that they may be integrated plasmids

    Moderate physical activity may prevent cartilage loss in women with knee osteoarthritis : data from the Osteoarthritis Initiative

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    All authors have completed the ICMJE uniform disclosure form at http://www.icmje.org/coi_disclosure.pdf and declare: data acquisition in this study was funded by the Osteoarthritis Initiative, a public–private partnership comprised of five contracts (N01-AR-2-2258; N01-AR-2-2259;N01-AR-2-2260; N01-AR-2-2261; N01-AR-2-2262) funded by the National Institutes of Health, a branch of the Department of Health and Human Services, and conducted by the Osteoarthritis Initiative study Investigators. Private funding partners of the OAI include Merck Research Laboratories, Novartis Pharmaceuticals Corporation, GlaxoSmithKline, and Pfizer, Inc. Private sector funding for the Osteoarthritis Initiative is managed by the Foundation for the National Institutes of Health. The image analysis in this study was partly funded by the FNIH OA Biomarkers Consortium, with grants, direct and in -kind contributions, provided by: AbbVie; Amgen Inc.; Arthritis Foundation; Bioiberica S.A.; DePuy Mitek, Inc.; Flexion Therapeutics, Inc.; GlaxoSmithKline; Merck KGaA; Rottapharm | Madaus; Sanofi; and Stryker. Other parts of funding were provided by a direct grant from Merck KGaA, by a contract with the University of Pittsburgh (Pivotal OAI MRI Analyses [POMA]: NIH/NHLBI Contract No. HHSN2682010000 21C), by a vendor contract from the OAI coordinating center at University of California, San Francisco (N01-AR-2-2258), and by an ancillary study to the OAI held by the Division of Rheumatology, Feinberg School of Medicine, Northwestern University (R01 AR52918). This research has also received funding from the European Union Seventh Framework Programme (FP7-PEOPLE-2013-ITN; KNEEMO) under grant agreement number 607510. AGC is supported by a National Health and Medical Research Council (NHMRC) of Australia Early Career Fellowship (Neil Hamilton Fairley Clinical Fellowship No.1121173). The sponsors were not involved in the design and conduct of this particular study, in the analysis and interpretation of the data, and in the preparation, review, or approval of the manuscript.Peer reviewedPostprin

    Nanoproteomic analysis of ischemia-dependent changes in signaling protein phosphorylation in colorectal normal and cancer tissue

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    Additional file 1: Table S1. Clinical data for the 20 patients analyzed in the study. Presents patient clinical data including tumor stage and grade

    Prevalence of pemphigus and pemphigoid autoantibodies in the general population

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    Background: Mucocutaneous blistering is characteristic of autoimmune bullous dermatoses (AIBD). Blisters are caused by autoantibodies directed against structural components of the skin. Hence, detection of specific autoantibodies has become a hallmark for AIBD diagnosis. Studies on prevalence of AIBD autoantibodies in healthy individuals yielded contradictory results. Methods: To clarify this, samples from 7063 blood donors were tested for presence of anti-BP180-NC16A, anti-BP230 and anti-Dsg1/3 IgG by indirect immunofluorescence (IF) microscopy using a biochip. Results: Cumulative prevalence of these autoantibodies was 0.9 % (CI: 0.7-1.1 %), with anti-BP180-NC16A IgG being most prevalent. Validation of IF findings using ELISA confirmed presence of autoantibodies in 7/15 (anti-Dsg1), 6/7 (anti-Dsg3), 35/37 (anti-BP180-NC16A) and 2/3 (anti-BP230) cases. Moreover, in 16 samples, anti-BP180-NC16A autoantibody concentrations exceeded the cut-off for the diagnosis of bullous pemphigoid. Interestingly, these anti-BP180-NC16A autoantibodies from healthy individuals formed immune complexes with recombinant antigen and dose-dependently activated neutrophils in vitro. However, fine-epitope mapping within NC16A showed a different binding pattern of anti-BP180-NC16A autoantibodies from healthy individuals compared to bullous pemphigoid patients, while IgG subclasses were identical. Conclusions: Collectively, we here report a low prevalence of AIBD autoantibodies in a large cohort of healthy individuals. Furthermore, functional analysis shows differences between autoantibodies from healthy donors and AIBD patients
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