3,853 research outputs found

    Localization and function of neurosecretory protein GM, a novel small secretory protein, in the chicken hypothalamus.

    Get PDF
    Recently, we discovered a novel cDNA encoding the precursor of a small secretory protein, neurosecretory protein GL (NPGL), in the hypothalamic infundibulum of chickens. NPGL plays an important role in the regulation of growth and feeding. A database search indicated that the NPGL gene has a paralogous gene: neurosecretory protein GM (NPGM), also in chickens. We identified cDNA encoding the NPGM precursor in chickens. Morphological analysis showed that NPGM-containing cells are specifically localized in the medial mammillary nucleus (MM) and infundibular nucleus (IN) in the hypothalamus. In addition, we found that NPGM and NPGL are co-localized, especially in the MM. The expression levels of NPGM mRNA gradually decreased during post-hatch development, in contrast to those of NPGL mRNA. Moreover, we investigated the relationship between NPGM and other known factors. NPGM was found to be produced in histaminergic neurons in the MM. NPGM and histidine decarboxylase, a histamine-producing enzyme, displayed similar expression patterns during post-hatch development. Acute intracerebroventricular injection of NPGM decreased food intake, similar to the effect of histamine. To our knowledge, this is the first report of the localization and function of NPGM in the brain of vertebrates. These results will further advance the understanding mechanisms underlying energy homeostasis

    Modelling and experimental validation of a fluidized bed reactor freeboard region: application to natural gas combustion

    Get PDF
    A theoretical and experimental study of natural gas-air mixture combustion in a fluidized bed of sand particles is presented. The operating temperatures are lower than a critical temperature of 800 °C above which the combustion occurs in the vicinity of the fluidized bed. Our study focusses on the freeboard zone where most of the methane combustion takes place at such temperatures. Experimental results show the essential role of the projection zone in determining the global thermal efficiency of the reactor. The dense bed temperature, the fluidizing velocity and the mean particle diameter significantly affect the thermal behaviours. A model for natural gas-air mixture combustion in fluidized beds is proposed, counting for interactions between dense and dilute regions of the reactor [Pré et al. (1998)] supplemented with the freeboard region modelling of Kunii-Levenspiel (1990). Thermal exchanges due to the convection between gas and particles, and due to the conduction and radiation phenomena between the gas-particle suspension and the reactor walls are counted. The kinetic scheme for the methane conversion is that proposed by Dryer and Glassman (1973). Model predictions are in good agreement with the measurements

    An Exploration of MODIS Cloud Regimes

    Get PDF
    Posters presented at the MODIS Science Team Meeting in Columbia, MD April 29-May 1 will be made available on the MODIS website

    Eribulin sensitizes oral squamous cell carcinoma cells to cetuximab via induction of mesenchymal-to-epithelial transition

    Get PDF
    Inhibition of epidermal growth factor receptor (EGFR) signalling has emerged as a new treatment strategy for oral squamous cell carcinoma (OSCC). Previously, we found that loss of EGFR expression in OSCC was associated with epithelial-mesenchymal transition (EMT), and may have functional implications with regard to resistance to cetuximab, a monoclonal anti-EGFR antibody. Eribulin (a microtubule inhibitor) reportedly renders breast cancer less aggressive, and less likely to metastasise, by triggering mesenchymal-to-epithelial (MET) transition. In the present study we evaluated whether eribulin-induced MET was associated with re-sensitization of resistant OSCC cell lines to cetuximab. In vitro antiproliferative activities were determined in three human OSCC lines (OSC-20, OSC-19 and HOC313) treated with eribulin. These three human OSCC represented different EMT/MET states. Interestingly, HOC313 cells (mesenchymal phenotype) were highly sensitive to eribulin in comparison with other cell lines, and significantly enhanced the anti-proliferative effect of cetuximab in response to the drug. Eribulin also underwent a MET-associated gene switch that resulted in morphological changes and high EGFR expression in HOC313 cells, and abrogated a TGF-β-induced EMT gene expression signature. Eribulin-dependent sensitization of OSCC to cetuximab is likely due to induction of MET. Combination therapies based on eribulin and cetuximab have potential as a novel treatment regimen in OSCC

    An Examination of the Nature of Global MODIS Cloud Regimes

    Get PDF
    We introduce global cloud regimes (previously also referred to as "weather states") derived from cloud retrievals that use measurements by the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument aboard the Aqua and Terra satellites. The regimes are obtained by applying clustering analysis on joint histograms of retrieved cloud top pressure and cloud optical thickness. By employing a compositing approach on data sets from satellites and other sources, we examine regime structural and thermodynamical characteristics. We establish that the MODIS cloud regimes tend to form in distinct dynamical and thermodynamical environments and have diverse profiles of cloud fraction and water content. When compositing radiative fluxes from the Clouds and the Earth's Radiant Energy System instrument and surface precipitation from the Global Precipitation Climatology Project, we find that regimes with a radiative warming effect on the atmosphere also produce the largest implied latent heat. Taken as a whole, the results of the study corroborate the usefulness of the cloud regime concept, reaffirm the fundamental nature of the regimes as appropriate building blocks for cloud system classification, clarify their association with standard cloud types, and underscore their distinct radiative and hydrological signatures

    The Emission from Inner Disk and Corona in the Low and Intermediate Spectral States of Black Hole X-ray Binaries

    Full text link
    Recent observations reveal that a cool disk may survive in the innermost stable circular orbit (ISCO) for some black hole X-ray binaries in the canonical low/hard state. The spectrum is characterized by a power law with a photon index Γ1.52.1\Gamma \sim 1.5-2.1 in the range of 2-10 keV and a weak disk component with temperature of 0.2\sim 0.2 keV. In this work, We revisit the formation of such a cool, optically thick, geometrically thin disk in the most inner region of black hole X-ray binaries at the low/hard state within the context of disk accretion fed by condensation of hot corona. By taking into account the cooling process associated with both Compton and conductive processes in a corona, and the irradiation of the hot corona to the disk, we calculate the structure of the corona. For viscosity parameter α=0.2\alpha=0.2, it's found that the inner disk can exist for accretion rate ranging from M˙0.0060.03M˙Edd\dot M \sim 0.006-0.03 \dot M_{\rm Edd}, over which the electron temperatures of the corona are in the range of 15×109 K1-5\times 10^9\ \rm K producing the hard X-ray emission. We calculate the emergent spectra of the inner disk and corona for different mass accretion rates. The effect of viscosity parameter α\alpha and albedo aa (aa is defined as the energy ratio of reflected radiation from the surface of the thin disk to incident radiation upon it from the corona) to the emergent spectra are also presented. Our model is used to explain the recent observations of GX 339-4 and Cyg X-1, in which the thin disk may exist at ISCO region in the low/hard state at luminosity around a few percent of LEddL_{\rm Edd}. It's found that the observed maximal effective temperature of the thermal component and the hard X-ray photon index Γ\Gamma can be matched well by our model.Comment: Accepted for publication by Ap

    Precision measurement of the n=2 triplet P J=1-to-J=0 fine structure of atomic helium using frequency-offset separated oscillatory fields

    Full text link
    Increasing accuracy of the theory and experiment of the nn==22 3^3P fine structure of helium has allowed for increasingly-precise tests of quantum electrodynamics (QED), determinations of the fine-structure constant α\alpha, and limitations on possible beyond-the-Standard-Model physics. Here we present a 2~part-per-billion (ppb) measurement of the JJ==11-to-JJ==00 interval. The measurement is performed using frequency-offset separated-oscillatory-fields. Our result of 29616955018(60)29\,616\,955\,018(60)~Hz represents a landmark for helium fine-structure measurements, and, for the first time, will allow for a 1-ppb determination of the fine-structure constant when QED theory for the interval is improved.Comment: 6 pages, 6 figures. arXiv admin note: substantial text overlap with arXiv:1807.0792

    Global smooth solutions and exponential stability for a nonlinear beam

    No full text
    Published versio

    Regulation of PD-L1 expression in a high-grade invasive human oral squamous cell carcinoma microenvironment

    Get PDF
    Blockade of the programmed-death 1 receptor (PD-1)/programmed-death ligand (PD-L1) pathway efficiently reduces tumour growth and improves survival. Durable tumour regression with blockade of the PD-1/PD-L1 checkpoint has been demonstrated in recent clinical studies. Oral squamous cell carcinoma (OSCC) is highly immunosuppressive, and PD-L1 expression has been proposed as a potential mechanism responsible for this phenotype. Despite the fact that anti-PD-1 treatment can produce durable responses, such therapy appears to benefit only a subset of patients. Thus, it is important to understand the mechanisms underlying regulation of PD-L1 expression in the OSCC microenvironment. In this study, we showed that PD-L1 expression in high-grade invasive OSCC cell lines was lower than that in a low-grade invasive OSCC line and found a close correlation between PD-L1 expression and the epithelial-mesenchymal transition (EMT). PD-L1 expression was upregulated in macrophages and dendritic cells (DCs) in high-grade invasive human OSCC tissues or co-cultured with mesenchymal-phenotype OSCC cells in vitro. TLR4-inhibitory peptide successfully suppressed PD-L1 upregulation on macrophages and DCs co-cultured with mesenchymal-phenotype OSCC cells, suggesting that some EMT-induced tumour antigen is critical for PD-L1 induction on tumour-associated macrophages and DCs. Further studies are necessary to explore the impact of EMT on the tumour immune microenvironment and to identify potential biomarkers for selecting patients who might preferentially benefit from PD-1/PD-L1 blockade or immunotherapies more broadly
    corecore