2,097 research outputs found

    An Atypical Presentation of a Rare Disease

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    A 76-year-old white woman presented for evaluation of asymptomatic skin lesions on her right shin, right buttock, and left arm. All lesions initially underwent slow growth and plateaued and then remained stable in size. A complete review of systems revealed normal results. She had 3 well-demarcated erythematous round plaques ranging from 1.5 to 3 cm, all with a central depression, yellow hue, and prominent telangiectasias (Figs 1 and 2). An excisional biopsy was performed. Histologically, there were palisading granulomas within the papillary and reticular dermis, predominantly composed of a histiocytic cell population with multiple large giant cells (S100-; Fig 3)

    Shaping nanoparticle fingerprints at the interface of cholesteric droplets

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    The ordering of nanoparticles into predetermined configurations is of importance to the design of advanced technologies. In this work, we moderate the surface anchoring against the bulk elasticity of liquid crystals to dynamically shape nanoparticle assemblies at a fluid interface. By tuning the degree of nanoparticle hydrophobicity with surfactants that alter the molecular anchoring of liquid crystals, we pattern nanoparticles at the interface of cholesteric liquid crystal emulsions. Adjusting the particle hydrophobicity more finely further modifies the rigidity of assemblies. We establish that patterns are tunable by varying both surfactant and chiral dopant concentrations. Since particle assembly occurs at the interface with the desired structures exposed to the surrounding phase, we demonstrate that particles can be readily crosslinked and manipulated, forming structures that retain their shape under external perturbations. This study establishes the templating of nanomaterials into reconfigurable arrangements. Interfacial assembly is tempered by elastic patterns that arise from the geometric frustration of confined cholesterics. This work serves as a basis for creating materials with chemical heterogeneity and with linear, periodic structures, essential for optical and energy applications.Comment: 16 pages with 5 figures, 4 page supplementary with 5 supplementary figure

    Elastocapillary driven assembly of particles at free-standing smectic-A films

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    Colloidal particles at complex fluid interfaces and within films assemble to form ordered structures with high degrees of symmetry via interactions that include capillarity, elasticity, and other fields like electrostatic charge. Here we study microparticle interactions within free-standing smectic-A films, in which the elasticity arising from the director field distortion and capillary interactions arising from interface deformation compete to direct the assembly of motile particles. New colloidal assemblies and patterns, ranging from 1D chains to 2D aggregates, sensitive to the initial wetting conditions of particles at the smectic film, are reported. This work paves the way to exploiting LC interfaces as a means to direct spontaneously formed, reconfigurable, and optically active materials.Comment: 8 pages, 6 figures. Supplementary Materials: 3 pages, 3 figure

    Shades of meaning: Uncovering the geometry of ambiguous word representations through contextualised language models

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    Lexical ambiguity presents a profound and enduring challenge to the language sciences. Researchers for decades have grappled with the problem of how language users learn, represent and process words with more than one meaning. Our work offers new insight into psychological understanding of lexical ambiguity through a series of simulations that capitalise on recent advances in contextual language models. These models have no grounded understanding of the meanings of words at all; they simply learn to predict words based on the surrounding context provided by other words. Yet, our analyses show that their representations capture fine-grained meaningful distinctions between unambiguous, homonymous, and polysemous words that align with lexicographic classifications and psychological theorising. These findings provide quantitative support for modern psychological conceptualisations of lexical ambiguity and raise new challenges for understanding of the way that contextual information shapes the meanings of words across different timescales

    Early-Life Socioeconomic Status and Adult Physiological Functioning: A Life Course Examination of Biosocial Mechanisms

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    A growing literature has demonstrated a link between early-life socioeconomic conditions and adult health at a singular point in life. No research exists, however, that specifies the life course patterns of socioeconomic status (SES) in relation to the underlying biological processes that determine health. Using an innovative life course research design consisting of four nationally representative longitudinal datasets that collectively cover the human life span from early adolescence to old age (Add Health, MIDUS, NSHAP, and HRS), we address this scientific gap and assess how SES pathways from childhood into adulthood are associated with biophysiological outcomes in different adult life stages. For each dataset, we constructed standardized, composite measures of early-life SES and adult SES and harmonized biophysiological measurements of immune and metabolic functioning. We found that the relative importance of early-life and adult SES varied across young-, mid-, and late-adulthood, such that early-life SES sets a life course trajectory of socioeconomic well-being and operates through adult SES to influence health as adults age. We also documented evidence of the detrimental health effects of downward mobility and persistent socioeconomic disadvantage. These findings are the first to specify the life course patterns of SES that matter for underlying biophysiological functioning in different stages of adulthood. The study thus contributes new knowledge critical for improving population health by identifying the particular points in the life course in which interventions might be most effective in preventing disease and premature mortality
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