871 research outputs found

    The dielectric constant of PbTe at 4.2 K and ν~\tilde ν=84.15 cm1^{-1}, 96.97 cm1^{-1}, 103.60 cm1^{-1}

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    The dielectric constant of a PbTe epitaxial layer has been measured by surface wave spectroscopy using an optically pumped far-infrared laser and the technique of attenuated total reflection

    Investigation of fluorescent properties of plasma exosomes in diagnosis and prognosis of colorectal cancer

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    Exosomes of blood plasma were studied using multiphoton tomography (two-photon microscopy). Exosomes were isolated in patients with colorectal cancer and in healthy donors. Images of fluorescence of exosomes were obtained at a wavelength of 760 nm and second harmonic generation at a wavelength of 380 nm. As a result of the analysis of the obtained data, qualitative differences were found between samples from patients with colorectal cancer and healthy donors

    Age-dependent alterations of monocyte subsets and monocyte-related chemokine pathways in healthy adults

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    <p>Abstract</p> <p>Background</p> <p>Recent experimental approaches have unraveled essential migratory and functional differences of monocyte subpopulations in mice. In order to possibly translate these findings into human physiology and pathophysiology, human monocyte subsets need to be carefully revisited in health and disease. In analogy to murine studies, we hypothesized that human monocyte subsets dynamically change during ageing, potentially influencing their functionality and contributing to immunosenescence.</p> <p>Results</p> <p>Circulating monocyte subsets, surface marker and chemokine receptor expression were analyzed in 181 healthy volunteers (median age 42, range 18-88). Unlike the unaffected total leukocyte or total monocyte counts, non-classical CD14<sup>+</sup>CD16<sup>+ </sup>monocytes significantly increased with age, but displayed reduced HLA-DR and CX<sub>3</sub>CR1 surface expression in the elderly. Classical CD14<sup>++</sup>CD16<sup>- </sup>monocyte counts did not vary dependent on age. Serum MCP-1 (CCL2), but not MIP1α (CCL3), MIP1β (CCL4) or fractalkine (CX<sub>3</sub>CL1) concentrations increased with age. Monocyte-derived macrophages from old or young individuals did not differ with respect to cytokine release <it>in vitro </it>at steady state or upon LPS stimulation.</p> <p>Conclusions</p> <p>Our study demonstrates dynamic changes of circulating monocytes during ageing in humans. The expansion of the non-classical CD14<sup>+</sup>CD16<sup>+ </sup>subtype, alterations of surface protein and chemokine receptor expression as well as circulating monocyte-related chemokines possibly contribute to the preserved functionality of the monocyte pool throughout adulthood.</p

    Relevance of Serum Leptin and Leptin-Receptor Concentrations in Critically Ill Patients

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    The adipocyte-derived cytokine leptin was implicated to link inflammation and metabolic alterations. We investigated the potential role of leptin components in critically ill patients, because systemic inflammation, insulin resistance, and hyperglycemia are common features of critical illness. Upon admission to Medical Intensive Care Unit (ICU), free leptin and soluble leptin-receptor serum concentrations were determined in 137 critically ill patients (95 with sepsis, 42 without sepsis) and 26 healthy controls. Serum leptin or leptin-receptor did not differ between patients or controls and were independent of sepsis. However, serum leptin was closely associated with obesity and diabetes and clearly correlated with markers of metabolism and liver function. Leptin-receptor was an unfavourable prognostic indicator, associated with mortality during three years follow-up. Our study indicates a functional role of leptin in the pathogenesis of severe illness and emphasizes the impact of complex metabolic alterations on the clinical outcome of critically ill patients
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