256 research outputs found

    Crystal growth furnace safety system validation

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    The findings are reported regarding the safe operation of the NASA crystal growth furnace (CGF) and potential methods for detecting containment failures of the furnace. The main conclusions are summarized by ampoule leak detection, cartridge leak detection, and detection of hazardous species in the experiment apparatus container (EAC)

    Microporous scaffolds loaded with immunomodulatory lentivirus to study the contribution of immune cell populations to tumor cell recruitment in vivo

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    Metastases are preceded by stochastic formation of a hospitable microenvironment known as the premetastatic niche, which has been difficult to study. Herein, we employ implantable polycaprolactone scaffolds as an engineered premetastatic niche to independently investigate the role of interleukin‐10 (IL10), CXCL12, and CCL2 in recruiting immune and tumor cells and impacting breast cancer cell phenotype via lentiviral overexpression. Lentivirus delivered from scaffolds in vivo achieved sustained transgene expression for 56 days. IL10 lentiviral expression, but not CXCL12 or CCL2, significantly decreased tumor cell recruitment to scaffolds in vivo. Delivery of CXCL12 enhanced CD45+ immune cell recruitment to scaffolds while delivery of IL10 reduced immune cell recruitment. CCL2 did not alter immune cell recruitment. Tumor cell phenotype was investigated using conditioned media from immunomodulated scaffolds, with CXCL12 microenvironments reducing proliferation, and IL10 microenvironments enhancing proliferation. Migration was enhanced with CCL2 and reduced with IL10‐driven microenvironments. Multiple linear regression identified populations of immune cells associated with tumor cell abundance. CD45+ immune and CD8+ T cells were associated with reduced tumor cell abundance, while CD11b+Gr1+ neutrophils and CD4+ T cells were associated with enhanced tumor cell abundance. Collectively, biomaterial scaffolds provide a tool to probe the formation and function of the premetastatic niche.Metastases are preceded by stochastic formation of a hospitable microenvironment known as the premetastatic niche, which has been difficult to study. Herein, we employ implantable polycaprolactone scaffolds as an engineered premetastatic niche to independently investigate the role of interleukin‐10 (IL10), CXCL12, and CCL2 in recruiting immune and tumor cells and impacting breast cancer cell phenotype via lentiviral overexpression.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/153114/1/bit27179.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/153114/2/bit27179_am.pd

    Polarized He-3 gas compression system using metastability-exchange optical pumping

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    Dense samples (10-100 bar cm) of nuclear spin polarized He-3 are utilized in high energy physics, neutron scattering, atomic physics, and magnetic resonance imaging. Metastability exchange optical pumping can rapidly produce high He-3 polarizations (≈ 80%) at low pressures (few mbar). We describe a polarized He-3 gas compressor system which accepts 0.26 bar l h(-1) of He-3 gas polarized to 70% by a 4 W neodymium doped lanthanum magnesium hexaluminate (Nd:LMA) laser and compresses it into a 5 bar cm target with final polarization of 55%. The spin relaxation rates of the system\u27s components have been measured using nuclear magnetic resonance and a model of the He-3 polarization loss based on the measured relaxation rates and the gas flow is in agreement with a He-3 polarization measurement using neutron transmission. © 2005 American Institute of Physics

    Search for Matter-Dependent Atmospheric Neutrino Oscillations in Super-Kamiokande

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    We consider muon neutrino to tau neutrino oscillations in the context of the Mass Varying Neutrino (MaVaN) model, where the neutrino mass can vary depending on the electron density along the flight path of the neutrino. Our analysis assumes a mechanism with dependence only upon the electron density, hence ordinary matter density, of the medium through which the neutrino travels. Fully-contained, partially-contained and upward-going muon atmospheric neutrino data from the Super--Kamiokande detector, taken from the entire SK--I period of 1489 live days, are compared to MaVaN model predictions. We find that, for the case of 2-flavor oscillations, and for the specific models tested, oscillation independent of electron density is favored over density dependence. Assuming maximal mixing, the best-fit case and the density-independent case do not differ significantly.Comment: 6 pages, 1 figur

    Olanzapine-Induced Hyperphagia and Weight Gain Associate with Orexigenic Hypothalamic Neuropeptide Signaling without Concomitant AMPK Phosphorylation

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    The success of antipsychotic drug treatment in patients with schizophrenia is limited by the propensity of these drugs to induce hyperphagia, weight gain and other metabolic disturbances, particularly evident for olanzapine and clozapine. However, the molecular mechanisms involved in antipsychotic-induced hyperphagia remain unclear. Here, we investigate the effect of olanzapine administration on the regulation of hypothalamic mechanisms controlling food intake, namely neuropeptide expression and AMP-activated protein kinase (AMPK) phosphorylation in rats. Our results show that subchronic exposure to olanzapine upregulates neuropeptide Y (NPY) and agouti related protein (AgRP) and downregulates proopiomelanocortin (POMC) in the arcuate nucleus of the hypothalamus (ARC). This effect was evident both in rats fed ad libitum and in pair-fed rats. Of note, despite weight gain and increased expression of orexigenic neuropeptides, subchronic administration of olanzapine decreased AMPK phosphorylation levels. This reduction in AMPK was not observed after acute administration of either olanzapine or clozapine. Overall, our data suggest that olanzapine-induced hyperphagia is mediated through appropriate changes in hypothalamic neuropeptides, and that this effect does not require concomitant AMPK activation. Our data shed new light on the hypothalamic mechanism underlying antipsychotic-induced hyperphagia and weight gain, and provide the basis for alternative targets to control energy balance
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