6,410 research outputs found

    SPICE compact modeling of bipolar/unipolar memristor switching governed by electrical thresholds

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    In this work we propose a physical memristor/resistive switching device SPICE compact model, that is able to accurately fit both unipolar/bipolar devices settling to its current-voltage relationship. The proposed model is capable of reproducing essential device characteristics such as multilevel storage, temperature dependence, cycle/event handling and even the evolution of variability/parameter degradation with time.The developed compact model has been validated against two physical devices, fitting unipolar and bipolar switching. With no requirement of Verilog-A code, LTSpice and Spectre simulations reproduce distinctive phenomena such as the preforming state, voltage/cycle dependent<br/

    Differential modulation of IL-8 and TNF-α expression in human keratinocytes by buflomedil chlorhydrate and pentoxifylline

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    Pentoxifylline (PTX) is a methylxanthine derivative used in a wide range of dermatoses. As well as its hemorrheologic activity, PTX has anti-inflammatory properties. Buflomedil chlorhydrate (BC) is another hemorrheological drug with peripheral vasodilatory action, whose clinical uses are similar to those of PTX. Both drugs increase intracellular levels of cAMP, either secondary to phosphodiesterase inhibition (PTX) or adenyl-cyclase stimulation (BC). Long-term cultures of normal human keratinocytes were prepared in a free-serum medium, and stimulated with 1 mg/ml of phorbol 12-myristate 13-acetate (TPA) and PTX or BC (100-1000 micrograms/ml). Levels of TNF-alpha, IL-1 alpha, IL-1 beta, IL-8 and TGF-beta 1 using ELISA and Northern blot or RT-PCR techniques were measured. TPA-induced TNF-alpha and IL-8 release from keratinocytes. TPA did not induce IL-1 alpha or IL-1 beta release of keratinocytes. TPA increased RNA expression of the TNF-alpha, IL-1 alpha, IL-1 beta, IL-8 and TGF-beta 1. BC diminished TPA-induced TNF-alpha and IL-8 release from keratinocytes; in the case of IL-8 it is possible that this inhibition occur to transcriptional level. Moreover PTX was unable to inhibit TNF-alpha and IL-8 synthesis and expression. PTX and BC reduced TPA-induced IL-1 alpha and beta expression. It is possible that BC action is specifically exerted on keratinocytes, because we did not find similar results with TNF-alpha and IL-8 synthesis in mononuclear peripheral blood cells

    Towards a new generation axion helioscope

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    We study the feasibility of a new generation axion helioscope, the most ambitious and promising detector of solar axions to date. We show that large improvements in magnetic field volume, x-ray focusing optics and detector backgrounds are possible beyond those achieved in the CERN Axion Solar Telescope (CAST). For hadronic models, a sensitivity to the axion-photon coupling of \gagamma\gtrsim {\rm few} \times 10^{-12} GeV1^{-1} is conceivable, 1--1.5 orders of magnitude beyond the CAST sensitivity. If axions also couple to electrons, the Sun produces a larger flux for the same value of the Peccei-Quinn scale, allowing one to probe a broader class of models. Except for the axion dark matter searches, this experiment will be the most sensitive axion search ever, reaching or surpassing the stringent bounds from SN1987A and possibly testing the axion interpretation of anomalous white-dwarf cooling that predicts mam_a of a few meV. Beyond axions, this new instrument will probe entirely unexplored ranges of parameters for a large variety of axion-like particles (ALPs) and other novel excitations at the low-energy frontier of elementary particle physics.Comment: 37 pages, 11 figures, accepted for publication in JCA

    The International Axion Observatory (IAXO)

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    The International Axion Observatory (IAXO) is a new generation axion helioscope aiming at a sensitivity to the axion-photon coupling of a few 1012^{12} GeV1^{-1}, i.e. 1 - 1.5 orders of magnitude beyond the one currently achieved by CAST. The project relies on improvements in magnetic field volume together with extensive use of x-ray focusing optics and low background detectors, innovations already successfully tested in CAST. Additional physics cases of IAXO could include the detection of electron-coupled axions invoked to solve the white dwarfs anomaly, relic axions, and a large variety of more generic axion-like particles (ALPs) and other novel excitations at the low-energy frontier of elementary particle physics. This contribution is a summary of our paper [1] to which we refer for further details.Comment: 4 pages, 2 figures. To appear in the proceedings of the 7th Patras Workshop on Axions, WIMPs and WISPs, Mykonos, Greece, 201

    SEOM clinical guideline in ovarian cancer (2020)

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    Despite remarkable advances in the knowledge of molecular biology and treatment, ovarian cancer remains the leading cause of death from gynecologic cancer. In the last decade, there have been important advances both in systemic and surgical treatment. However, there is no doubt that the incorporation of PARP inhibitors as maintenance after the response to platinum-based chemotherapy, first in recurrent disease and recently also in first line, will change the natural history of the disease. The objective of this guide is to summarize the current evidence for the diagnosis, treatment, and follow-up of ovarian cancer, and to provide evidence-based recommendations for clinical practice

    Operational experience, improvements, and performance of the CDF Run II silicon vertex detector

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    The Collider Detector at Fermilab (CDF) pursues a broad physics program at Fermilab's Tevatron collider. Between Run II commissioning in early 2001 and the end of operations in September 2011, the Tevatron delivered 12 fb-1 of integrated luminosity of p-pbar collisions at sqrt(s)=1.96 TeV. Many physics analyses undertaken by CDF require heavy flavor tagging with large charged particle tracking acceptance. To realize these goals, in 2001 CDF installed eight layers of silicon microstrip detectors around its interaction region. These detectors were designed for 2--5 years of operation, radiation doses up to 2 Mrad (0.02 Gy), and were expected to be replaced in 2004. The sensors were not replaced, and the Tevatron run was extended for several years beyond its design, exposing the sensors and electronics to much higher radiation doses than anticipated. In this paper we describe the operational challenges encountered over the past 10 years of running the CDF silicon detectors, the preventive measures undertaken, and the improvements made along the way to ensure their optimal performance for collecting high quality physics data. In addition, we describe the quantities and methods used to monitor radiation damage in the sensors for optimal performance and summarize the detector performance quantities important to CDF's physics program, including vertex resolution, heavy flavor tagging, and silicon vertex trigger performance.Comment: Preprint accepted for publication in Nuclear Instruments and Methods A (07/31/2013

    CAST constraints on the axion-electron coupling

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    In non-hadronic axion models, which have a tree-level axion-electron interaction, the Sun produces a strong axion flux by bremsstrahlung, Compton scattering, and axio-recombination, the "BCA processes." Based on a new calculation of this flux, including for the first time axio-recombination, we derive limits on the axion-electron Yukawa coupling g_ae and axion-photon interaction strength g_ag using the CAST phase-I data (vacuum phase). For m_a < 10 meV/c2 we find g_ag x g_ae< 8.1 x 10^-23 GeV^-1 at 95% CL. We stress that a next-generation axion helioscope such as the proposed IAXO could push this sensitivity into a range beyond stellar energy-loss limits and test the hypothesis that white-dwarf cooling is dominated by axion emission

    Positive words carry less information than negative words

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    We show that the frequency of word use is not only determined by the word length \cite{Zipf1935} and the average information content \cite{Piantadosi2011}, but also by its emotional content. We have analyzed three established lexica of affective word usage in English, German, and Spanish, to verify that these lexica have a neutral, unbiased, emotional content. Taking into account the frequency of word usage, we find that words with a positive emotional content are more frequently used. This lends support to Pollyanna hypothesis \cite{Boucher1969} that there should be a positive bias in human expression. We also find that negative words contain more information than positive words, as the informativeness of a word increases uniformly with its valence decrease. Our findings support earlier conjectures about (i) the relation between word frequency and information content, and (ii) the impact of positive emotions on communication and social links.Comment: 16 pages, 3 figures, 3 table

    CAST constraints on the axion-electron coupling

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    In non-hadronic axion models, which have a tree-level axion-electron interaction, the Sun produces a strong axion flux by bremsstrahlung, Compton scattering, and axiorecombination, the "BCA processes." Based on a new calculation of this flux, including for the first time axio-recombination, we derive limits on the axion-electron Yukawa coupling gae and axion-photon interaction strength ga using the CAST phase-I data (vacuum phase). For ma <~ 10 meV/c2 we find ga gae < 8.1 × 10−23 GeV−1 at 95% CL. We stress that a next-generation axion helioscope such as the proposed IAXO could push this sensitivity into a range beyond stellar energy-loss limits and test the hypothesis that white-dwarf cooling is dominated by axion emission

    Nivolumab and sunitinib combination in advanced soft tissue sarcomas : A multicenter, single-arm, phase Ib/II trial

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    Sarcomas exhibit low expression of factors related to immune response, which could explain the modest activity of PD-1 inhibitors. A potential strategy to convert a cold into an inflamed microenvironment lies on a combination therapy. As tumor angiogenesis promotes immunosuppression, we designed a phase Ib/II trial to test the double inhibition of angiogenesis (sunitinib) and PD-1/PD-L1 axis (nivolumab). This single-arm, phase Ib/II trial enrolled adult patients with selected subtypes of sarcoma. Phase Ib established two dose levels: level 0 with sunitinib 37.5 mg daily from day 1, plus nivolumab 3 mg/kg intravenously on day 15, and then every 2 weeks; and level-1 with sunitinib 37.5 mg on the first 14 days (induction) and then 25 mg per day plus nivolumab on the same schedule. The primary endpoint was to determine the recommended dose for phase II (phase I) and the 6-month progression-free survival rate, according to Response Evaluation Criteria in Solid Tumors 1.1 (phase II). From May 2017 to April 2019, 68 patients were enrolled: 16 in phase Ib and 52 in phase II. The recommended dose of sunitinib for phase II was 37.5 mg as induction and then 25 mg in combination with nivolumab. After a median follow-up of 17 months (4-26), the 6-month progression-free survival rate was 48% (95% CI 41% to 55%). The most common grade 3-4 adverse events included transaminitis (17.3%) and neutropenia (11.5%). Sunitinib plus nivolumab is an active scheme with manageable toxicity in the treatment of selected patients with advanced soft tissue sarcoma, with almost half of patients free of progression at 6 months
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