363 research outputs found

    Thermoremanence acquisition and demagnetization for titanomagnetite under lithospheric pressures

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    ©2017. American Geophysical Union.The geological sources of large-scale lithospheric magnetic field anomalies are poorly constrained. Understanding the magnetic behavior of rocks and minerals under the pressures and temperatures encountered at large crustal depths is particularly important in that task. The impact of lithospheric pressure is not well known and most of the time neglected in numerical models of the geological sources of magnetic anomalies. We present thermal remanent magnetization (TRM) acquisition and stepwise thermal demagnetization on synthetic titanomagnetite dispersed powder, within an amagnetic cell under hydrostatic pressure up to 1 GPa. TRM is measured after thermal cycling within a cryogenic magnetometer. Pressure-dependent increase in the Curie temperature (initially in the 50-70°C range) is observed, mostly between 0.3 and 0.6 GPa, on the order of 20 K/GPa. TRM intensity also increases with pressure up to 200% at 675 MPa, although the pressure variation with temperature inside the cell complicates the interpretation

    Inhibiting the oncogenic translation program is an effective therapeutic strategy in multiple myeloma

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    Published in final edited form as: Sci Transl Med. 2017 May 10; 9(389). https://doi.org/10.1126/scitranslmed.aal2668.Multiple myeloma (MM) is a frequently incurable hematological cancer in which overactivity of MYC plays a central role, notably through up-regulation of ribosome biogenesis and translation. To better understand the oncogenic program driven by MYC and investigate its potential as a therapeutic target, we screened a chemically diverse small-molecule library for anti-MM activity. The most potent hits identified were rocaglate scaffold inhibitors of translation initiation. Expression profiling of MM cells revealed reversion of the oncogenic MYC-driven transcriptional program by CMLD010509, the most promising rocaglate. Proteome-wide reversion correlated with selective depletion of short-lived proteins that are key to MM growth and survival, most notably MYC, MDM2, CCND1, MAF, and MCL-1. The efficacy of CMLD010509 in mouse models of MM confirmed the therapeutic relevance of these findings in vivo and supports the feasibility of targeting the oncogenic MYC-driven translation program in MM with rocaglates

    The effect of hydrostatic pressure up to 1.61 GPa on the Morin transition of hematite-bearing rocks: Implications for planetary crustal magnetization

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    © 2015. American Geophysical Union. All Rights Reserved. We present new experimental data on the dependence of the Morin transition temperature (TM) on hydrostatic pressure up to 1.61 GPa, obtained on a well-characterized multidomain hematite-bearing sample from a banded iron formation. We used a nonmagnetic high-pressure cell for pressure application and a Superconducting Quantum Interference Device magnetometer to measure the isothermal remanent magnetization (IRM) under pressure on warming from 243 K to room temperature (T0). IRM imparted at T0 under pressure in 270 mT magnetic field (IRM270mT) is not recovered after a cooling-warming cycle. Memory effect under pressure was quantified as IRM recovery decrease of 10%/GPa. TM, determined on warming, reaches T0 under hydrostatic pressure 1.38-1.61 GPa. The pressure dependence of TM up to 1.61 GPa is positive and essentially linear with a slope dTM/dP = (25 ± 2) K/GPa. This estimate is more precise than previous ones and allows quantifying the effect of a pressure wave on the upper crust magnetization, with special emphasis on Mars

    New Integrated High-Resolution Dinoflagellate Cyst Stratigraphy and Litho- and Chemostratigraphy from the Paris and Dieppe–Hampshire Basins for the “Sparnacian”

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    The Paris Basin represents an historical cradle of Palaeogene stratigraphy, where during the nineteenth century the Palaeocene Series and the “Sparnacian Stage” were established. As highlighted by Aubry et al. (2005), whereas the chronostratigraphic connotation of the “Sparnacian Stage” has been controversial since its definition, modern studies of the late Palaeocene–early Eocene interval have revealed that the so-called “Sparnacian” deposits encompass a remarkable and short (~170 kyr) episode of the Cenozoic, the Palaeocene–Eocene Thermal Maximum (PETM, ~55.8–55.6 Ma). Dinoflagellate assemblages from the “Sparnacian” of the Dieppe–Hampshire and Paris basins do not contain the key species Apectodinium augustum, whereas it is present in the northern Belgian Basin Tienen Formation and is coeval there with the CIE and the Apectodinium acme interval. However, our calibration of the Apectodinium acme to the CIE in the Dieppe–Hampshire and Paris basins suggests its attribution to the A. augustum zone. The absence of species A. augustum in the Anglo–Paris Basin may be explained by its restriction to more offshore conditions

    Sleep quality in middle-aged and elderly Chinese: distribution, associated factors and associations with cardio-metabolic risk factors

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    Background Poor sleep quality has been associated with increased risk of heart disease, diabetes and mortality. However, limited information exists on the distribution and determinants of sleep quality and its associations with cardio-metabolic risk factors in Chinese populations. We aimed to evaluate this in the current study. Methods A cross-sectional survey conducted in 2005 of 1,458 men and 1,831 women aged 50–70 years from urban and rural areas of Beijing and Shanghai. Using a questionnaire, sleep quality was measured in levels of well, common and poor. Comprehensive measures of socio-demographical and health factors and biomarkers of cardio-metabolic disease were recorded. These were evaluated in association with sleep quality using logistic regression models. Results Half of the population reported good sleep quality. After adjusting for potential confounders, women and Beijing residents had almost half the probability to report good sleep quality. Good physical and mental health (good levels of self-rated health (OR 2.48; 95%CI 2.08 to 2.96) and no depression (OR 4.05; 95%CI 3.12 to 5.26)) related to an increased chance of reporting good sleep quality, whereas short sleep duration (<7 hrs OR 0.10; 95%CI 0.07 to 0.14)) decreased it substantially. There were significant associations between levels of sleep quality and concentrations of plasma insulin, total and LDL cholesterol, and index of insulin resistance. Conclusion Levels of good sleep quality in middle-age and elderly Chinese were low. Gender, geographical location, self-rated health, depression and sleep quantity were major factors associated with sleep quality. Prospective studies are required to distil the factors that determine sleep quality and the effects that sleep patterns exert on cardio-metabolic health

    Stromal regulatory T-cells are associated with a favourable prognosis in gastric cancer of the cardia

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    <p>Abstract</p> <p>Background</p> <p>Recent evidence suggests that CD4<sup>+</sup>CD25<sup>+</sup>FoxP3<sup>+ </sup>regulatory T-cells (Treg) may be responsible for the failure of host anti-tumour immunity by suppressing cytotoxic T- cells. We assessed the prognostic significance of tumour infiltrating lymphocytes (TIL) in intestinal-type gastric cardiac cancer.</p> <p>Methods</p> <p>Tumour infiltrating lymphocyte (TIL) subsets and tumour infiltrating macrophages (TIM) were investigated in 52 cases using tissue microarrays. The interrelationship between the cell populations (CD3+, CD8+, CD20+, CD68+, GranzymeB+, FoxP3+) in different compartments and NED-survival was investigated (median follow-up time: 61 months).</p> <p>Results</p> <p>Intraepithelial infiltration with TIL and TIM including Treg was generally low and not related to NED-survival. However, patients with large numbers of FoxP3<sup>+ </sup>Treg in the tumour stroma (>125.9 FoxP3<sup>+</sup>TILs/mm<sup>2</sup>) had a median survival time of 58 months while those with low FoxP3<sup>+ </sup>TIL counts (<125.9 FoxP3<sup>+</sup>TILs/mm<sup>2</sup>) had a median survival time of 32 months (p = 0.006). Patients with high versus low stromal CD68<sup>+</sup>/FoxP3<sup>+ </sup>cell ratios in primary tumour displayed median survivals of 32 and 55 months, respectively (p = 0.008).</p> <p>Conclusion</p> <p>Our results suggest that inflammatory processes within the tumour stroma of gastric intestinal-type adenocarcinomas located at the gastric cardia may affect outcome in two ways. Tumour-infiltrating macrophages are likely to promote carcinogenesis while large numbers of Treg are associated with improved outcome probably by inhibiting local inflammatory processes promoting carcinogenesis. Thus, inhibition of Treg may not be a feasible treatment option in gastric adenocarcinoma.</p

    Thermal plasma synthesis of Li2S nanoparticles for application in lithium-sulfur batteries

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    Abstract : Inductively-coupled thermal plasma processes were used to produce nanosized Li2S. Prior to the syntheses, the feasibility of forming Li2S was first evaluated using FactSage by considering the phase diagrams of sulfur and different lithium precursors in reducing atmospheres; Li2O, LiOH·H2O, Li2CO3 and Li2SO4·H2O all showed promises in producing Li2S nanoparticles, as confirmed by experiments. Argon and hydrogen mixtures were used as plasma gases, and a carbothermal reduction was implemented for Li2SO4·H2O. In addition, carbon-coated Li2S nanoparticles were synthesized with downstream injection of methane. Carbon was shown to stabilize Li2S upon contact with ambient air. The Li2S nanoparticles were electrochemically tested in half-cells using electrolytes containing LiNO3 or Li2S6 as additives. It was found that adding LiNO3 to the electrolyte was detrimental to the electrochemical performance of Li2S, whereas the combination of Li2S6 and LiNO3 as additives doubled the charge and discharge capacities of the half-cell over 10 cycles
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